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Merge tag 'for-6.16/block-20250523' of git://git.kernel.dk/linux
Pull block updates from Jens Axboe:
- ublk updates:
- Add support for updating the size of a ublk instance
- Zero-copy improvements
- Auto-registering of buffers for zero-copy
- Series simplifying and improving GET_DATA and request lookup
- Series adding quiesce support
- Lots of selftests additions
- Various cleanups
- NVMe updates via Christoph:
- add per-node DMA pools and use them for PRP/SGL allocations
(Caleb Sander Mateos, Keith Busch)
- nvme-fcloop refcounting fixes (Daniel Wagner)
- support delayed removal of the multipath node and optionally
support the multipath node for private namespaces (Nilay Shroff)
- support shared CQs in the PCI endpoint target code (Wilfred
Mallawa)
- support admin-queue only authentication (Hannes Reinecke)
- use the crc32c library instead of the crypto API (Eric Biggers)
- misc cleanups (Christoph Hellwig, Marcelo Moreira, Hannes
Reinecke, Leon Romanovsky, Gustavo A. R. Silva)
- MD updates via Yu:
- Fix that normal IO can be starved by sync IO, found by mkfs on
newly created large raid5, with some clean up patches for bdev
inflight counters
- Clean up brd, getting rid of atomic kmaps and bvec poking
- Add loop driver specifically for zoned IO testing
- Eliminate blk-rq-qos calls with a static key, if not enabled
- Improve hctx locking for when a plug has IO for multiple queues
pending
- Remove block layer bouncing support, which in turn means we can
remove the per-node bounce stat as well
- Improve blk-throttle support
- Improve delay support for blk-throttle
- Improve brd discard support
- Unify IO scheduler switching. This should also fix a bunch of lockdep
warnings we've been seeing, after enabling lockdep support for queue
freezing/unfreezeing
- Add support for block write streams via FDP (flexible data placement)
on NVMe
- Add a bunch of block helpers, facilitating the removal of a bunch of
duplicated boilerplate code
- Remove obsolete BLK_MQ pci and virtio Kconfig options
- Add atomic/untorn write support to blktrace
- Various little cleanups and fixes
* tag 'for-6.16/block-20250523' of git://git.kernel.dk/linux: (186 commits)
selftests: ublk: add test for UBLK_F_QUIESCE
ublk: add feature UBLK_F_QUIESCE
selftests: ublk: add test case for UBLK_U_CMD_UPDATE_SIZE
traceevent/block: Add REQ_ATOMIC flag to block trace events
ublk: run auto buf unregisgering in same io_ring_ctx with registering
io_uring: add helper io_uring_cmd_ctx_handle()
ublk: remove io argument from ublk_auto_buf_reg_fallback()
ublk: handle ublk_set_auto_buf_reg() failure correctly in ublk_fetch()
selftests: ublk: add test for covering UBLK_AUTO_BUF_REG_FALLBACK
selftests: ublk: support UBLK_F_AUTO_BUF_REG
ublk: support UBLK_AUTO_BUF_REG_FALLBACK
ublk: register buffer to local io_uring with provided buf index via UBLK_F_AUTO_BUF_REG
ublk: prepare for supporting to register request buffer automatically
ublk: convert to refcount_t
selftests: ublk: make IO & device removal test more stressful
nvme: rename nvme_mpath_shutdown_disk to nvme_mpath_remove_disk
nvme: introduce multipath_always_on module param
nvme-multipath: introduce delayed removal of the multipath head node
nvme-pci: derive and better document max segments limits
nvme-pci: use struct_size for allocation struct nvme_dev
...
Merge cpufreq updates for 6.16-rc1:
- Refactor cpufreq_online(), add and use cpufreq policy locking guards,
use __free() in policy reference counting, and clean up core cpufreq
code on top of that (Rafael Wysocki).
- Fix boost handling on CPU suspend/resume and sysfs updates (Viresh
Kumar).
- Fix des_perf clamping with max_perf in amd_pstate_update() (Dhananjay
Ugwekar).
- Add offline, online and suspend callbacks to the amd-pstate driver,
rename and use the existing amd_pstate_epp callbacks in it (Dhananjay
Ugwekar).
- Add support for the "Requested CPU Min frequency" BIOS option to the
amd-pstate driver (Dhananjay Ugwekar).
- Reset amd-pstate driver mode after running selftests (Swapnil
Sapkal).
- Add helper for governor checks to the schedutil cpufreq governor and
move cpufreq-specific EAS checks to cpufreq (Rafael Wysocki).
- Populate the cpu_capacity sysfs entries from the intel_pstate driver
after registering asym capacity support (Ricardo Neri).
- Add support for enabling Energy-aware scheduling (EAS) to the
intel_pstate driver when operating in the passive mode on a hybrid
platform (Rafael Wysocki).
- Avoid shadowing ret in amd_pstate_ut_check_driver() (Nathan
Chancellor).
- Drop redundant cpus_read_lock() from store_local_boost() in the
cpufreq core (Seyediman Seyedarab).
- Replace sscanf() with kstrtouint() in the cpufreq code and use a
symbol instead of a raw number in it (Bowen Yu).
- Add support for autonomous CPU performance state selection to the
CPPC cpufreq driver (Lifeng Zheng).
* pm-cpufreq: (31 commits)
cpufreq: CPPC: Add support for autonomous selection
cpufreq: Update sscanf() to kstrtouint()
cpufreq: Replace magic number
cpufreq: drop redundant cpus_read_lock() from store_local_boost()
cpufreq/amd-pstate: Avoid shadowing ret in amd_pstate_ut_check_driver()
cpufreq: intel_pstate: Document hybrid processor support
cpufreq: intel_pstate: EAS: Increase cost for CPUs using L3 cache
cpufreq: intel_pstate: EAS support for hybrid platforms
cpufreq: Drop policy locking from cpufreq_policy_is_good_for_eas()
cpufreq: intel_pstate: Populate the cpu_capacity sysfs entries
arch_topology: Relocate cpu_scale to topology.[h|c]
cpufreq/sched: Move cpufreq-specific EAS checks to cpufreq
cpufreq/sched: schedutil: Add helper for governor checks
amd-pstate-ut: Reset amd-pstate driver mode after running selftests
cpufreq/amd-pstate: Add support for the "Requested CPU Min frequency" BIOS option
cpufreq/amd-pstate: Add offline, online and suspend callbacks for amd_pstate_driver
cpufreq: Force sync policy boost with global boost on sysfs update
cpufreq: Preserve policy's boost state after resume
cpufreq: Introduce policy_set_boost()
cpufreq: Don't unnecessarily call set_boost()
...
Merge energy model management code updates for 6.16-rc1:
- Fix potential division-by-zero error in em_compute_costs() (Yaxiong
Tian).
- Fix typos in energy model documentation and example driver code (Moon
Hee Lee, Atul Kumar Pant).
- Rearrange the energy model management code and add a new function for
adjusting a CPU energy model after adjusting the capacity of the
given CPU to it (Rafael Wysocki).
* pm-em:
PM: EM: Introduce em_adjust_cpu_capacity()
PM: EM: Move CPU capacity check to em_adjust_new_capacity()
PM: EM: Documentation: Fix typos in example driver code
PM: EM: Documentation: fix typo in energy-model.rst
PM: EM: Fix potential division-by-zero error in em_compute_costs()
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Merge tag 'vfs-6.16-rc1.pidfs' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull pidfs updates from Christian Brauner:
"Features:
- Allow handing out pidfds for reaped tasks for AF_UNIX SO_PEERPIDFD
socket option
SO_PEERPIDFD is a socket option that allows to retrieve a pidfd for
the process that called connect() or listen(). This is heavily used
to safely authenticate clients in userspace avoiding security bugs
due to pid recycling races (dbus, polkit, systemd, etc.)
SO_PEERPIDFD currently doesn't support handing out pidfds if the
sk->sk_peer_pid thread-group leader has already been reaped. In
this case it currently returns EINVAL. Userspace still wants to get
a pidfd for a reaped process to have a stable handle it can pass
on. This is especially useful now that it is possible to retrieve
exit information through a pidfd via the PIDFD_GET_INFO ioctl()'s
PIDFD_INFO_EXIT flag
Another summary has been provided by David Rheinsberg:
> A pidfd can outlive the task it refers to, and thus user-space
> must already be prepared that the task underlying a pidfd is
> gone at the time they get their hands on the pidfd. For
> instance, resolving the pidfd to a PID via the fdinfo must be
> prepared to read `-1`.
>
> Despite user-space knowing that a pidfd might be stale, several
> kernel APIs currently add another layer that checks for this. In
> particular, SO_PEERPIDFD returns `EINVAL` if the peer-task was
> already reaped, but returns a stale pidfd if the task is reaped
> immediately after the respective alive-check.
>
> This has the unfortunate effect that user-space now has two ways
> to check for the exact same scenario: A syscall might return
> EINVAL/ESRCH/... *or* the pidfd might be stale, even though
> there is no particular reason to distinguish both cases. This
> also propagates through user-space APIs, which pass on pidfds.
> They must be prepared to pass on `-1` *or* the pidfd, because
> there is no guaranteed way to get a stale pidfd from the kernel.
>
> Userspace must already deal with a pidfd referring to a reaped
> task as the task may exit and get reaped at any time will there
> are still many pidfds referring to it
In order to allow handing out reaped pidfd SO_PEERPIDFD needs to
ensure that PIDFD_INFO_EXIT information is available whenever a
pidfd for a reaped task is created by PIDFD_INFO_EXIT. The uapi
promises that reaped pidfds are only handed out if it is guaranteed
that the caller sees the exit information:
TEST_F(pidfd_info, success_reaped)
{
struct pidfd_info info = {
.mask = PIDFD_INFO_CGROUPID | PIDFD_INFO_EXIT,
};
/*
* Process has already been reaped and PIDFD_INFO_EXIT been set.
* Verify that we can retrieve the exit status of the process.
*/
ASSERT_EQ(ioctl(self->child_pidfd4, PIDFD_GET_INFO, &info), 0);
ASSERT_FALSE(!!(info.mask & PIDFD_INFO_CREDS));
ASSERT_TRUE(!!(info.mask & PIDFD_INFO_EXIT));
ASSERT_TRUE(WIFEXITED(info.exit_code));
ASSERT_EQ(WEXITSTATUS(info.exit_code), 0);
}
To hand out pidfds for reaped processes we thus allocate a pidfs
entry for the relevant sk->sk_peer_pid at the time the
sk->sk_peer_pid is stashed and drop it when the socket is
destroyed. This guarantees that exit information will always be
recorded for the sk->sk_peer_pid task and we can hand out pidfds
for reaped processes
- Hand a pidfd to the coredump usermode helper process
Give userspace a way to instruct the kernel to install a pidfd for
the crashing process into the process started as a usermode helper.
There's still tricky race-windows that cannot be easily or
sometimes not closed at all by userspace. There's various ways like
looking at the start time of a process to make sure that the
usermode helper process is started after the crashing process but
it's all very very brittle and fraught with peril
The crashed-but-not-reaped process can be killed by userspace
before coredump processing programs like systemd-coredump have had
time to manually open a PIDFD from the PID the kernel provides
them, which means they can be tricked into reading from an
arbitrary process, and they run with full privileges as they are
usermode helper processes
Even if that specific race-window wouldn't exist it's still the
safest and cleanest way to let the kernel provide the pidfd
directly instead of requiring userspace to do it manually. In
parallel with this commit we already have systemd adding support
for this in [1]
When the usermode helper process is forked we install a pidfd file
descriptor three into the usermode helper's file descriptor table
so it's available to the exec'd program
Since usermode helpers are either children of the system_unbound_wq
workqueue or kthreadd we know that the file descriptor table is
empty and can thus always use three as the file descriptor number
Note, that we'll install a pidfd for the thread-group leader even
if a subthread is calling do_coredump(). We know that task linkage
hasn't been removed yet and even if this @current isn't the actual
thread-group leader we know that the thread-group leader cannot be
reaped until
@current has exited
- Allow telling when a task has not been found from finding the wrong
task when creating a pidfd
We currently report EINVAL whenever a struct pid has no tasked
attached anymore thereby conflating two concepts:
(1) The task has already been reaped
(2) The caller requested a pidfd for a thread-group leader but the
pid actually references a struct pid that isn't used as a
thread-group leader
This is causing issues for non-threaded workloads as in where they
expect ESRCH to be reported, not EINVAL
So allow userspace to reliably distinguish between (1) and (2)
- Make it possible to detect when a pidfs entry would outlive the
struct pid it pinned
- Add a range of new selftests
Cleanups:
- Remove unneeded NULL check from pidfd_prepare() for passed struct
pid
- Avoid pointless reference count bump during release_task()
Fixes:
- Various fixes to the pidfd and coredump selftests
- Fix error handling for replace_fd() when spawning coredump usermode
helper"
* tag 'vfs-6.16-rc1.pidfs' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
pidfs: detect refcount bugs
coredump: hand a pidfd to the usermode coredump helper
coredump: fix error handling for replace_fd()
pidfs: move O_RDWR into pidfs_alloc_file()
selftests: coredump: Raise timeout to 2 minutes
selftests: coredump: Fix test failure for slow machines
selftests: coredump: Properly initialize pointer
net, pidfs: enable handing out pidfds for reaped sk->sk_peer_pid
pidfs: get rid of __pidfd_prepare()
net, pidfs: prepare for handing out pidfds for reaped sk->sk_peer_pid
pidfs: register pid in pidfs
net, pidfd: report EINVAL for ESRCH
release_task: kill the no longer needed get/put_pid(thread_pid)
pidfs: ensure consistent ENOENT/ESRCH reporting
exit: move wake_up_all() pidfd waiters into __unhash_process()
selftest/pidfd: add test for thread-group leader pidfd open for thread
pidfd: improve uapi when task isn't found
pidfd: remove unneeded NULL check from pidfd_prepare()
selftests/pidfd: adapt to recent changes
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Merge tag 'vfs-6.16-rc1.super' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull vfs freezing updates from Christian Brauner:
"This contains various filesystem freezing related work for this cycle:
- Allow the power subsystem to support filesystem freeze for suspend
and hibernate.
Now all the pieces are in place to actually allow the power
subsystem to freeze/thaw filesystems during suspend/resume.
Filesystems are only frozen and thawed if the power subsystem does
actually own the freeze.
If the filesystem is already frozen by the time we've frozen all
userspace processes we don't care to freeze it again. That's
userspace's job once the process resumes. We only actually freeze
filesystems if we absolutely have to and we ignore other failures
to freeze.
We could bubble up errors and fail suspend/resume if the error
isn't EBUSY (aka it's already frozen) but I don't think that this
is worth it. Filesystem freezing during suspend/resume is
best-effort. If the user has 500 ext4 filesystems mounted and 4
fail to freeze for whatever reason then we simply skip them.
What we have now is already a big improvement and let's see how we
fare with it before making our lives even harder (and uglier) than
we have to.
- Allow efivars to support freeze and thaw
Allow efivarfs to partake to resync variable state during system
hibernation and suspend. Add freeze/thaw support.
This is a pretty straightforward implementation. We simply add
regular freeze/thaw support for both userspace and the kernel.
efivars is the first pseudofilesystem that adds support for
filesystem freezing and thawing.
The simplicity comes from the fact that we simply always resync
variable state after efivarfs has been frozen. It doesn't matter
whether that's because of suspend, userspace initiated freeze or
hibernation. Efivars is simple enough that it doesn't matter that
we walk all dentries. There are no directories and there aren't
insane amounts of entries and both freeze/thaw are already
heavy-handed operations. If userspace initiated a freeze/thaw cycle
they would need CAP_SYS_ADMIN in the initial user namespace (as
that's where efivarfs is mounted) so it can't be triggered by
random userspace. IOW, we really really don't care"
* tag 'vfs-6.16-rc1.super' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
f2fs: fix freezing filesystem during resize
kernfs: add warning about implementing freeze/thaw
efivarfs: support freeze/thaw
power: freeze filesystems during suspend/resume
libfs: export find_next_child()
super: add filesystem freezing helpers for suspend and hibernate
gfs2: pass through holder from the VFS for freeze/thaw
super: use common iterator (Part 2)
super: use a common iterator (Part 1)
super: skip dying superblocks early
super: simplify user_get_super()
super: remove pointless s_root checks
fs: allow all writers to be frozen
locking/percpu-rwsem: add freezable alternative to down_read
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Merge tag 'vfs-6.16-rc1.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull misc vfs updates from Christian Brauner:
"This contains the usual selections of misc updates for this cycle.
Features:
- Use folios for symlinks in the page cache
FUSE already uses folios for its symlinks. Mirror that conversion
in the generic code and the NFS code. That lets us get rid of a few
folio->page->folio conversions in this path, and some of the few
remaining users of read_cache_page() / read_mapping_page()
- Try and make a few filesystem operations killable on the VFS
inode->i_mutex level
- Add sysctl vfs_cache_pressure_denom for bulk file operations
Some workloads need to preserve more dentries than we currently
allow through out sysctl interface
A HDFS servers with 12 HDDs per server, on a HDFS datanode startup
involves scanning all files and caching their metadata (including
dentries and inodes) in memory. Each HDD contains approximately 2
million files, resulting in a total of ~20 million cached dentries
after initialization
To minimize dentry reclamation, they set vfs_cache_pressure to 1.
Despite this configuration, memory pressure conditions can still
trigger reclamation of up to 50% of cached dentries, reducing the
cache from 20 million to approximately 10 million entries. During
the subsequent cache rebuild period, any HDFS datanode restart
operation incurs substantial latency penalties until full cache
recovery completes
To maintain service stability, more dentries need to be preserved
during memory reclamation. The current minimum reclaim ratio (1/100
of total dentries) remains too aggressive for such workload. This
patch introduces vfs_cache_pressure_denom for more granular cache
pressure control
The configuration [vfs_cache_pressure=1,
vfs_cache_pressure_denom=10000] effectively maintains the full 20
million dentry cache under memory pressure, preventing datanode
restart performance degradation
- Avoid some jumps in inode_permission() using likely()/unlikely()
- Avid a memory access which is most likely a cache miss when
descending into devcgroup_inode_permission()
- Add fastpath predicts for stat() and fdput()
- Anonymous inodes currently don't come with a proper mode causing
issues in the kernel when we want to add useful VFS debug assert.
Fix that by giving them a proper mode and masking it off when we
report it to userspace which relies on them not having any mode
- Anonymous inodes currently allow to change inode attributes because
the VFS falls back to simple_setattr() if i_op->setattr isn't
implemented. This means the ownership and mode for every single
user of anon_inode_inode can be changed. Block that as it's either
useless or actively harmful. If specific ownership is needed the
respective subsystem should allocate anonymous inodes from their
own private superblock
- Raise SB_I_NODEV and SB_I_NOEXEC on the anonymous inode superblock
- Add proper tests for anonymous inode behavior
- Make it easy to detect proper anonymous inodes and to ensure that
we can detect them in codepaths such as readahead()
Cleanups:
- Port pidfs to the new anon_inode_{g,s}etattr() helpers
- Try to remove the uselib() system call
- Add unlikely branch hint return path for poll
- Add unlikely branch hint on return path for core_sys_select
- Don't allow signals to interrupt getdents copying for fuse
- Provide a size hint to dir_context for during readdir()
- Use writeback_iter directly in mpage_writepages
- Update compression and mtime descriptions in initramfs
documentation
- Update main netfs API document
- Remove useless plus one in super_cache_scan()
- Remove unnecessary NULL-check guards during setns()
- Add separate separate {get,put}_cgroup_ns no-op cases
Fixes:
- Fix typo in root= kernel parameter description
- Use KERN_INFO for infof()|info_plog()|infofc()
- Correct comments of fs_validate_description()
- Mark an unlikely if condition with unlikely() in
vfs_parse_monolithic_sep()
- Delete macro fsparam_u32hex()
- Remove unused and problematic validate_constant_table()
- Fix potential unsigned integer underflow in fs_name()
- Make file-nr output the total allocated file handles"
* tag 'vfs-6.16-rc1.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (43 commits)
fs: Pass a folio to page_put_link()
nfs: Use a folio in nfs_get_link()
fs: Convert __page_get_link() to use a folio
fs/read_write: make default_llseek() killable
fs/open: make do_truncate() killable
fs/open: make chmod_common() and chown_common() killable
include/linux/fs.h: add inode_lock_killable()
readdir: supply dir_context.count as readdir buffer size hint
vfs: Add sysctl vfs_cache_pressure_denom for bulk file operations
fuse: don't allow signals to interrupt getdents copying
Documentation: fix typo in root= kernel parameter description
include/cgroup: separate {get,put}_cgroup_ns no-op case
kernel/nsproxy: remove unnecessary guards
fs: use writeback_iter directly in mpage_writepages
fs: remove useless plus one in super_cache_scan()
fs: add S_ANON_INODE
fs: remove uselib() system call
device_cgroup: avoid access to ->i_rdev in the common case in devcgroup_inode_permission()
fs/fs_parse: Remove unused and problematic validate_constant_table()
fs: touch up predicts in inode_permission()
...
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Merge tag 'vfs-6.16-rc1.async.dir' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull vfs directory lookup updates from Christian Brauner:
"This contains cleanups for the lookup_one*() family of helpers.
We expose a set of functions with names containing "lookup_one_len"
and others without the "_len". This difference has nothing to do with
"len". It's rater a historical accident that can be confusing.
The functions without "_len" take a "mnt_idmap" pointer. This is found
in the "vfsmount" and that is an important question when choosing
which to use: do you have a vfsmount, or are you "inside" the
filesystem. A related question is "is permission checking relevant
here?".
nfsd and cachefiles *do* have a vfsmount but *don't* use the non-_len
functions. They pass nop_mnt_idmap and refuse to work on filesystems
which have any other idmap.
This work changes nfsd and cachefile to use the lookup_one family of
functions and to explictily pass &nop_mnt_idmap which is consistent
with all other vfs interfaces used where &nop_mnt_idmap is explicitly
passed.
The remaining uses of the "_one" functions do not require permission
checks so these are renamed to be "_noperm" and the permission
checking is removed.
This series also changes these lookup function to take a qstr instead
of separate name and len. In many cases this simplifies the call"
* tag 'vfs-6.16-rc1.async.dir' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
VFS: change lookup_one_common and lookup_noperm_common to take a qstr
Use try_lookup_noperm() instead of d_hash_and_lookup() outside of VFS
VFS: rename lookup_one_len family to lookup_noperm and remove permission check
cachefiles: Use lookup_one() rather than lookup_one_len()
nfsd: Use lookup_one() rather than lookup_one_len()
VFS: improve interface for lookup_one functions
or aren't considered necessary for -stable kernels. 19 are for MM.
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Merge tag 'mm-hotfixes-stable-2025-05-25-00-58' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull hotfixes from Andrew Morton:
"22 hotfixes.
13 are cc:stable and the remainder address post-6.14 issues or aren't
considered necessary for -stable kernels. 19 are for MM"
* tag 'mm-hotfixes-stable-2025-05-25-00-58' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (22 commits)
mailmap: add Jarkko's employer email address
mm: fix copy_vma() error handling for hugetlb mappings
memcg: always call cond_resched() after fn()
mm/hugetlb: fix kernel NULL pointer dereference when replacing free hugetlb folios
mm: vmalloc: only zero-init on vrealloc shrink
mm: vmalloc: actually use the in-place vrealloc region
alloc_tag: allocate percpu counters for module tags dynamically
module: release codetag section when module load fails
mm/cma: make detection of highmem_start more robust
MAINTAINERS: add mm memory policy section
MAINTAINERS: add mm ksm section
kasan: avoid sleepable page allocation from atomic context
highmem: add folio_test_partial_kmap()
MAINTAINERS: add hung-task detector section
taskstats: fix struct taskstats breaks backward compatibility since version 15
mm/truncate: fix out-of-bounds when doing a right-aligned split
MAINTAINERS: add mm reclaim section
MAINTAINERS: update page allocator section
mm: fix VM_UFFD_MINOR == VM_SHADOW_STACK on USERFAULTFD=y && ARM64_GCS=y
mm: mmap: map MAP_STACK to VM_NOHUGEPAGE only if THP is enabled
...
Sean noted that scripts/Makefile.lib:name-fix-token rule will mangle
the module name with s/-/_/g.
Since this happens late in the build, only the kernel needs to bother
with this, the modpost tool still sees the original name.
Reported-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Tested-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Petr Pavlu <petr.pavlu@suse.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Instead of only accepting "module:${name}", extend it with a comma
separated list of module names and add tail glob support.
That is, something like: "module:foo-*,bar" is now possible.
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Reviewed-by: Petr Pavlu <petr.pavlu@suse.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Designate the "module:${modname}" symbol namespace to mean: 'only
export to the named module'.
Notably, explicit imports of anything in the "module:" space is
forbidden.
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Reviewed-by: Petr Pavlu <petr.pavlu@suse.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
When module load fails after memory for codetag section is ready, codetag
section memory will not be properly released. This causes memory leak,
and if next module load happens to get the same module address, codetag
may pick the uninitialized section when manipulating tags during module
unload, and leads to "unable to handle page fault" BUG.
Link: https://lkml.kernel.org/r/20250519163823.7540-1-00107082@163.com
Fixes: 0db6f8d782 ("alloc_tag: load module tags into separate contiguous memory")
Closes: https://lore.kernel.org/all/20250516131246.6244-1-00107082@163.com/
Signed-off-by: David Wang <00107082@163.com>
Acked-by: Suren Baghdasaryan <surenb@google.com>
Cc: Petr Pavlu <petr.pavlu@suse.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
On error, copy_from_user returns number of bytes not copied to
destination, but current implementation of copy_user_data_sleepable does
not handle that correctly and returns it as error value, which may
confuse user, expecting meaningful negative error value.
Fixes: a498ee7576 ("bpf: Implement dynptr copy kfuncs")
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20250523181705.261585-1-mykyta.yatsenko5@gmail.com
User space needs access to kernel BTF for many modern features of BPF.
Right now each process needs to read the BTF blob either in pieces or
as a whole. Allow mmaping the sysfs file so that processes can directly
access the memory allocated for it in the kernel.
remap_pfn_range is used instead of vm_insert_page due to aarch64
compatibility issues.
Signed-off-by: Lorenz Bauer <lmb@isovalent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Tested-by: Alan Maguire <alan.maguire@oracle.com>
Reviewed-by: Shakeel Butt <shakeel.butt@linux.dev>
Link: https://lore.kernel.org/bpf/20250520-vmlinux-mmap-v5-1-e8c941acc414@isovalent.com
Filesystems like XFS can implement atomic write I/O using either
REQ_ATOMIC flag set in the bio or via CoW operation. It will be useful
if we have a flag in trace events to distinguish between the two. This
patch adds char 'U' (Untorn writes) to rwbs field of the trace events
if REQ_ATOMIC flag is set in the bio.
<W/ REQ_ATOMIC>
=================
xfs_io-4238 [009] ..... 4148.126843: block_rq_issue: 259,0 WFSU 16384 () 768 + 32 none,0,0 [xfs_io]
<idle>-0 [009] d.h1. 4148.129864: block_rq_complete: 259,0 WFSU () 768 + 32 none,0,0 [0]
<W/O REQ_ATOMIC>
===============
xfs_io-4237 [010] ..... 4143.325616: block_rq_issue: 259,0 WS 16384 () 768 + 32 none,0,0 [xfs_io]
<idle>-0 [010] d.H1. 4143.329138: block_rq_complete: 259,0 WS () 768 + 32 none,0,0 [0]
Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://lore.kernel.org/r/44317cb2ec4588f6a2c1501a96684e6a1196e8ba.1747921498.git.ritesh.list@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
PVH dom0 is useless without XEN_UNPOPULATED_ALLOC, as otherwise it will
very likely balloon out all dom0 memory to map foreign and grant pages.
Enable it by default as part of xen.config. This also requires enabling
MEMORY_HOTREMOVE and ZONE_DEVICE.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Message-ID: <20250514092037.28970-1-roger.pau@citrix.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
The "try_" prefix is confusing, since it made people believe that
try_alloc_pages() is analogous to spin_trylock() and NULL return means
EAGAIN. This is not the case. If it returns NULL there is no reason to
call it again. It will most likely return NULL again. Hence rename it to
alloc_pages_nolock() to make it symmetrical to free_pages_nolock() and
document that NULL means ENOMEM.
Link: https://lkml.kernel.org/r/20250517003446.60260-1-alexei.starovoitov@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Harry Yoo <harry.yoo@oracle.com>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
BPF schedulers that use both builtin CPU idle mechanism and
ops.update_idle() may want to use the latter to create interlocking between
ops.enqueue() and CPU idle transitions so that either ops.enqueue() sees the
idle bit or ops.update_idle() sees the task queued somewhere. This can
prevent race conditions where CPUs go idle while tasks are waiting in DSQs.
For such interlocking to work, ops.update_idle() must be called after
builtin CPU masks are updated. Relocate the invocation. Currently, there are
no ordering requirements on transitions from idle and this relocation isn't
expected to make meaningful differences in that direction.
This also makes the ops.update_idle() behavior semantically consistent:
any action performed in this callback should be able to override the
builtin idle state, not the other way around.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-and-tested-by: Andrea Righi <arighi@nvidia.com>
Acked-by: Changwoo Min <changwoo@igalia.com>
Other subsystems may make use of the cgroup hierarchy with the cgroup_bpf
support being one such example. For such a feature, it's useful to be able
to hook into cgroup creation and destruction paths to perform
feature-specific initializations and cleanups.
Add cgroup_lifetime_notifier which generates CGROUP_LIFETIME_ONLINE and
CGROUP_LIFETIME_OFFLINE events whenever cgroups are created and destroyed,
respectively.
The next patch will convert cgroup_bpf to use the new notifier and other
uses are planned.
Signed-off-by: Tejun Heo <tj@kernel.org>
cgroup_bpf init and exit handling will be moved to a notifier chain. In
prepartion, reorganize cgroup_create() a bit so that the new cgroup is fully
initialized before any outside changes are made.
- cgrp->ancestors[] initialization and the hierarchical nr_descendants and
nr_frozen_descendants updates were in the same loop. Separate them out and
do the former earlier and do the latter later.
- Relocate cgroup_bpf_inherit() call so that it's after all cgroup
initializations are complete.
No visible behavior changes expected.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cross-merge networking fixes after downstream PR (net-6.15-rc8).
Conflicts:
80f2ab46c2 ("irdma: free iwdev->rf after removing MSI-X")
4bcc063939 ("ice, irdma: fix an off by one in error handling code")
c24a65b6a2 ("iidc/ice/irdma: Update IDC to support multiple consumers")
https://lore.kernel.org/20250513130630.280ee6c5@canb.auug.org.au
No extra adjacent changes.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This reverts commit 4a8f635a60.
Althought get_pid_task() internally already calls rcu_read_lock() and
rcu_read_unlock(), the find_vpid() was not.
The documentation for find_vpid() clearly states:
"Must be called with the tasklist_lock or rcu_read_lock() held."
Add proper rcu_read_lock/unlock() to protect the find_vpid().
Fixes: 4a8f635a60 ("bpf: remove unnecessary rcu_read_{lock,unlock}() in multi-uprobe attach logic")
Reported-by: Xuewen Yan <xuewen.yan@unisoc.com>
Signed-off-by: Di Shen <di.shen@unisoc.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20250520054943.5002-1-xuewen.yan@unisoc.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Subsystem rstat locks are dynamically allocated per-cpu. It was discovered
that a panic can occur during this allocation when the lock size is zero.
This is the case on non-smp systems, since arch_spinlock_t is defined as an
empty struct. Prevent this allocation when !CONFIG_SMP by adding a
pre-processor conditional around the affected block.
Signed-off-by: JP Kobryn <inwardvessel@gmail.com>
Reported-by: Klara Modin <klarasmodin@gmail.com>
Fixes: 748922dcfa ("cgroup: use subsystem-specific rstat locks to avoid contention")
Signed-off-by: Tejun Heo <tj@kernel.org>
The current allocation of VMAP stack memory is using (THREADINFO_GFP &
~__GFP_ACCOUNT) which is a complicated way of saying (GFP_KERNEL |
__GFP_ZERO):
<linux/thread_info.h>:
define THREADINFO_GFP (GFP_KERNEL_ACCOUNT | __GFP_ZERO)
<linux/gfp_types.h>:
define GFP_KERNEL_ACCOUNT (GFP_KERNEL | __GFP_ACCOUNT)
This is an unfortunate side-effect of independent changes blurring the
picture:
commit 19809c2da2 changed (THREADINFO_GFP |
__GFP_HIGHMEM) to just THREADINFO_GFP since highmem became implicit.
commit 9b6f7e163c then added stack caching
and rewrote the allocation to (THREADINFO_GFP & ~__GFP_ACCOUNT) as cached
stacks need to be accounted separately. However that code, when it
eventually accounts the memory does this:
ret = memcg_kmem_charge(vm->pages[i], GFP_KERNEL, 0)
so the memory is charged as a GFP_KERNEL allocation.
Define a unique GFP_VMAP_STACK to use
GFP_KERNEL | __GFP_ZERO and move the comment there.
Link: https://lkml.kernel.org/r/20250509-gfp-stack-v1-1-82f6f7efc210@linaro.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Reported-by: Mateusz Guzik <mjguzik@gmail.com>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
There are two data types: "struct vm_struct" and "struct vm_stack" that
have the same local variable names: vm_stack, or vm, or s, which makes the
code confusing to read.
Change the code so the naming is consistent:
struct vm_struct is always called vm_area
struct vm_stack is always called vm_stack
One change altering vfree(vm_stack) to vfree(vm_area->addr) may look like
a semantic change but it is not: vm_area->addr points to the vm_stack.
This was done to improve readability.
[linus.walleij@linaro.org: rebased and added new users of the variable names, address review comments]
Link: https://lore.kernel.org/20240311164638.2015063-4-pasha.tatashin@soleen.com
Link: https://lkml.kernel.org/r/20250509-fork-fixes-v3-2-e6c69dd356f2@linaro.org
Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "fork: Page operation cleanups in the fork code", v3.
This patchset consists of outtakes from a 1 year+ old patchset from Pasha,
which all stand on their own. See:
https://lore.kernel.org/all/20240311164638.2015063-1-pasha.tatashin@soleen.com/
These are good cleanups for readability so I split these off, rebased on
v6.15-rc1, addressed review comments and send them separately.
All mentions of dynamic stack are removed from the patchset as we have no
idea whether that will go anywhere.
This patch (of 3):
There is unneeded OR in the ifdef functions that are used to allocate and
free kernel stacks based on direct map or vmap.
Therefore, clean up by changing the order so OR is no longer needed.
[linus.walleij@linaro.org: rebased]
Link: https://lkml.kernel.org/r/20250509-fork-fixes-v3-1-e6c69dd356f2@linaro.org
Link: https://lkml.kernel.org/r/20250509-fork-fixes-v3-0-e6c69dd356f2@linaro.org
Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Link: https://lore.kernel.org/20240311164638.2015063-3-pasha.tatashin@soleen.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "sysfs: add counters for lockups and stalls", v2.
Commits 9db89b4111 ("exit: Expose "oops_count" to sysfs") and
8b05aa2633 ("panic: Expose "warn_count" to sysfs") added counters for
oopses and warnings to sysfs, and these two patches do the same for
hard/soft lockups and RCU stalls.
All of these counters are useful for monitoring tools to detect whether
the machine is healthy. If the kernel has experienced a lockup or a
stall, it's probably due to a kernel bug, and I'd like to detect that
quickly and easily. There is currently no way to detect that, other than
parsing dmesg. Or observing indirect effects: such as certain tasks not
responding, but then I need to observe all tasks, and it may take a while
until these effects become visible/measurable. I'd rather be able to
detect the primary cause more quickly, possibly before everything falls
apart.
This patch (of 2):
There is /proc/sys/kernel/hung_task_detect_count, /sys/kernel/warn_count
and /sys/kernel/oops_count but there is no userspace-accessible counter
for hard/soft lockups. Having this is useful for monitoring tools.
Link: https://lkml.kernel.org/r/20250504180831.4190860-1-max.kellermann@ionos.com
Link: https://lkml.kernel.org/r/20250504180831.4190860-2-max.kellermann@ionos.com
Signed-off-by: Max Kellermann <max.kellermann@ionos.com>
Cc:
Cc: Core Minyard <cminyard@mvista.com>
Cc: Doug Anderson <dianders@chromium.org>
Cc: Joel Granados <joel.granados@kernel.org>
Cc: Song Liu <song@kernel.org>
Cc: Kees Cook <kees@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Crash kernel will retrieve the dm crypt keys based on the dmcryptkeys
command line parameter. When user space writes the key description to
/sys/kernel/config/crash_dm_crypt_key/restore, the crash kernel will save
the encryption keys to the user keyring. Then user space e.g.
cryptsetup's --volume-key-keyring API can use it to unlock the encrypted
device.
Link: https://lkml.kernel.org/r/20250502011246.99238-6-coxu@redhat.com
Signed-off-by: Coiby Xu <coxu@redhat.com>
Acked-by: Baoquan He <bhe@redhat.com>
Cc: "Daniel P. Berrange" <berrange@redhat.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Jan Pazdziora <jpazdziora@redhat.com>
Cc: Liu Pingfan <kernelfans@gmail.com>
Cc: Milan Broz <gmazyland@gmail.com>
Cc: Ondrej Kozina <okozina@redhat.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
When there are CPU and memory hot un/plugs, the dm crypt keys may need to
be reloaded again depending on the solution for crash hotplug support.
Currently, there are two solutions. One is to utilizes udev to instruct
user space to reload the kdump kernel image and initrd, elfcorehdr and etc
again. The other is to only update the elfcorehdr segment introduced in
commit 2472627561 ("crash: add generic infrastructure for crash hotplug
support").
For the 1st solution, the dm crypt keys need to be reloaded again. The
user space can write true to /sys/kernel/config/crash_dm_crypt_key/reuse
so the stored keys can be re-used.
For the 2nd solution, the dm crypt keys don't need to be reloaded.
Currently, only x86 supports the 2nd solution. If the 2nd solution gets
extended to all arches, this patch can be dropped.
Link: https://lkml.kernel.org/r/20250502011246.99238-5-coxu@redhat.com
Signed-off-by: Coiby Xu <coxu@redhat.com>
Acked-by: Baoquan He <bhe@redhat.com>
Cc: "Daniel P. Berrange" <berrange@redhat.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Jan Pazdziora <jpazdziora@redhat.com>
Cc: Liu Pingfan <kernelfans@gmail.com>
Cc: Milan Broz <gmazyland@gmail.com>
Cc: Ondrej Kozina <okozina@redhat.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
When the kdump kernel image and initrd are loaded, the dm crypts keys will
be read from keyring and then stored in kdump reserved memory.
Assume a key won't exceed 256 bytes thus MAX_KEY_SIZE=256 according to
"cryptsetup benchmark".
Link: https://lkml.kernel.org/r/20250502011246.99238-4-coxu@redhat.com
Signed-off-by: Coiby Xu <coxu@redhat.com>
Acked-by: Baoquan He <bhe@redhat.com>
Cc: "Daniel P. Berrange" <berrange@redhat.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Jan Pazdziora <jpazdziora@redhat.com>
Cc: Liu Pingfan <kernelfans@gmail.com>
Cc: Milan Broz <gmazyland@gmail.com>
Cc: Ondrej Kozina <okozina@redhat.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
A configfs /sys/kernel/config/crash_dm_crypt_keys is provided for user
space to make the dm crypt keys persist for the kdump kernel. Take the
case of dumping to a LUKS-encrypted target as an example, here is the life
cycle of the kdump copies of LUKS volume keys,
1. After the 1st kernel loads the initramfs during boot, systemd uses
an user-input passphrase to de-crypt the LUKS volume keys or simply
TPM-sealed volume keys and then save the volume keys to specified
keyring (using the --link-vk-to-keyring API) and the keys will expire
within specified time.
2. A user space tool (kdump initramfs loader like kdump-utils) create
key items inside /sys/kernel/config/crash_dm_crypt_keys to inform
the 1st kernel which keys are needed.
3. When the kdump initramfs is loaded by the kexec_file_load
syscall, the 1st kernel will iterate created key items, save the
keys to kdump reserved memory.
4. When the 1st kernel crashes and the kdump initramfs is booted, the
kdump initramfs asks the kdump kernel to create a user key using the
key stored in kdump reserved memory by writing yes to
/sys/kernel/crash_dm_crypt_keys/restore. Then the LUKS encrypted
device is unlocked with libcryptsetup's --volume-key-keyring API.
5. The system gets rebooted to the 1st kernel after dumping vmcore to
the LUKS encrypted device is finished
Eventually the keys have to stay in the kdump reserved memory for the
kdump kernel to unlock encrypted volumes. During this process, some
measures like letting the keys expire within specified time are desirable
to reduce security risk.
This patch assumes,
1) there are 128 LUKS devices at maximum to be unlocked thus
MAX_KEY_NUM=128.
2) a key description won't exceed 128 bytes thus KEY_DESC_MAX_LEN=128.
And here is a demo on how to interact with
/sys/kernel/config/crash_dm_crypt_keys,
# Add key #1
mkdir /sys/kernel/config/crash_dm_crypt_keys/7d26b7b4-e342-4d2d-b660-7426b0996720
# Add key #1's description
echo cryptsetup:7d26b7b4-e342-4d2d-b660-7426b0996720 > /sys/kernel/config/crash_dm_crypt_keys/description
# how many keys do we have now?
cat /sys/kernel/config/crash_dm_crypt_keys/count
1
# Add key# 2 in the same way
# how many keys do we have now?
cat /sys/kernel/config/crash_dm_crypt_keys/count
2
# the tree structure of /crash_dm_crypt_keys configfs
tree /sys/kernel/config/crash_dm_crypt_keys/
/sys/kernel/config/crash_dm_crypt_keys/
├── 7d26b7b4-e342-4d2d-b660-7426b0996720
│ └── description
├── count
├── fce2cd38-4d59-4317-8ce2-1fd24d52c46a
│ └── description
Link: https://lkml.kernel.org/r/20250502011246.99238-3-coxu@redhat.com
Signed-off-by: Coiby Xu <coxu@redhat.com>
Acked-by: Baoquan He <bhe@redhat.com>
Cc: "Daniel P. Berrange" <berrange@redhat.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Jan Pazdziora <jpazdziora@redhat.com>
Cc: Liu Pingfan <kernelfans@gmail.com>
Cc: Milan Broz <gmazyland@gmail.com>
Cc: Ondrej Kozina <okozina@redhat.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "Support kdump with LUKS encryption by reusing LUKS volume
keys", v9.
LUKS is the standard for Linux disk encryption, widely adopted by users,
and in some cases, such as Confidential VMs, it is a requirement. With
kdump enabled, when the first kernel crashes, the system can boot into the
kdump/crash kernel to dump the memory image (i.e., /proc/vmcore) to a
specified target. However, there are two challenges when dumping vmcore
to a LUKS-encrypted device:
- Kdump kernel may not be able to decrypt the LUKS partition. For some
machines, a system administrator may not have a chance to enter the
password to decrypt the device in kdump initramfs after the 1st kernel
crashes; For cloud confidential VMs, depending on the policy the
kdump kernel may not be able to unseal the keys with TPM and the
console virtual keyboard is untrusted.
- LUKS2 by default use the memory-hard Argon2 key derivation function
which is quite memory-consuming compared to the limited memory reserved
for kdump. Take Fedora example, by default, only 256M is reserved for
systems having memory between 4G-64G. With LUKS enabled, ~1300M needs
to be reserved for kdump. Note if the memory reserved for kdump can't
be used by 1st kernel i.e. an user sees ~1300M memory missing in the
1st kernel.
Besides users (at least for Fedora) usually expect kdump to work out of
the box i.e. no manual password input or custom crashkernel value is
needed. And it doesn't make sense to derivate the keys again in kdump
kernel which seems to be redundant work.
This patchset addresses the above issues by making the LUKS volume keys
persistent for kdump kernel with the help of cryptsetup's new APIs
(--link-vk-to-keyring/--volume-key-keyring). Here is the life cycle of
the kdump copies of LUKS volume keys,
1. After the 1st kernel loads the initramfs during boot, systemd
use an user-input passphrase to de-crypt the LUKS volume keys
or TPM-sealed key and then save the volume keys to specified keyring
(using the --link-vk-to-keyring API) and the key will expire within
specified time.
2. A user space tool (kdump initramfs loader like kdump-utils) create
key items inside /sys/kernel/config/crash_dm_crypt_keys to inform
the 1st kernel which keys are needed.
3. When the kdump initramfs is loaded by the kexec_file_load
syscall, the 1st kernel will iterate created key items, save the
keys to kdump reserved memory.
4. When the 1st kernel crashes and the kdump initramfs is booted, the
kdump initramfs asks the kdump kernel to create a user key using the
key stored in kdump reserved memory by writing yes to
/sys/kernel/crash_dm_crypt_keys/restore. Then the LUKS encrypted
device is unlocked with libcryptsetup's --volume-key-keyring API.
5. The system gets rebooted to the 1st kernel after dumping vmcore to
the LUKS encrypted device is finished
After libcryptsetup saving the LUKS volume keys to specified keyring,
whoever takes this should be responsible for the safety of these copies of
keys. The keys will be saved in the memory area exclusively reserved for
kdump where even the 1st kernel has no direct access. And further more,
two additional protections are added,
- save the copy randomly in kdump reserved memory as suggested by Jan
- clear the _PAGE_PRESENT flag of the page that stores the copy as
suggested by Pingfan
This patchset only supports x86. There will be patches to support other
architectures once this patch set gets merged.
This patch (of 9):
Currently, kexec_buf is placed in order which means for the same machine,
the info in the kexec_buf is always located at the same position each time
the machine is booted. This may cause a risk for sensitive information
like LUKS volume key. Now struct kexec_buf has a new field random which
indicates it's supposed to be placed in a random position.
Note this feature is enabled only when CONFIG_CRASH_DUMP is enabled. So
it only takes effect for kdump and won't impact kexec reboot.
Link: https://lkml.kernel.org/r/20250502011246.99238-1-coxu@redhat.com
Link: https://lkml.kernel.org/r/20250502011246.99238-2-coxu@redhat.com
Signed-off-by: Coiby Xu <coxu@redhat.com>
Suggested-by: Jan Pazdziora <jpazdziora@redhat.com>
Acked-by: Baoquan He <bhe@redhat.com>
Cc: "Daniel P. Berrange" <berrange@redhat.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Liu Pingfan <kernelfans@gmail.com>
Cc: Milan Broz <gmazyland@gmail.com>
Cc: Ondrej Kozina <okozina@redhat.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
There is no reason to restrict scx_bpf_select_cpu_dfl() invocations to
ops.select_cpu() while allowing scx_bpf_select_cpu_and() to be used from
multiple contexts, as both provide equivalent functionality, with the
latter simply accepting an additional "allowed" cpumask.
Therefore, unify the two APIs, enabling both kfuncs to be used from
ops.select_cpu(), ops.enqueue(), and unlocked contexts (e.g., via BPF
test_run).
This allows schedulers to implement a consistent idle CPU selection
policy and helps reduce code duplication.
Signed-off-by: Andrea Righi <arighi@nvidia.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
&desc->lock is acquired on 2 consecutive lines in hwirq_show(). This leads
obviously to a deadlock. Drop the raw_spin_lock_irq() and keep guard().
Fixes: 5d964a9f7c ("genirq/irqdesc: Switch to lock guards")
Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20250521142541.3832130-1-claudiu.beznea.uj@bp.renesas.com
The PERF_RECORD_THROTTLE records are dumped for all throttled events.
It's not necessary for group events, which are throttled altogether.
Optimize it by only dump the throttle log for the leader.
The sample right after the THROTTLE record must be generated by the
actual target event. It is good enough for the perf tool to locate the
actual target event.
Suggested-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20250520181644.2673067-3-kan.liang@linux.intel.com
The current throttle logic doesn't work well with a group, e.g., the
following sampling-read case.
$ perf record -e "{cycles,cycles}:S" ...
$ perf report -D | grep THROTTLE | tail -2
THROTTLE events: 426 ( 9.0%)
UNTHROTTLE events: 425 ( 9.0%)
$ perf report -D | grep PERF_RECORD_SAMPLE -a4 | tail -n 5
0 1020120874009167 0x74970 [0x68]: PERF_RECORD_SAMPLE(IP, 0x1):
... sample_read:
.... group nr 2
..... id 0000000000000327, value 000000000cbb993a, lost 0
..... id 0000000000000328, value 00000002211c26df, lost 0
The second cycles event has a much larger value than the first cycles
event in the same group.
The current throttle logic in the generic code only logs the THROTTLE
event. It relies on the specific driver implementation to disable
events. For all ARCHs, the implementation is similar. Only the event is
disabled, rather than the group.
The logic to disable the group should be generic for all ARCHs. Add the
logic in the generic code. The following patch will remove the buggy
driver-specific implementation.
The throttle only happens when an event is overflowed. Stop the entire
group when any event in the group triggers the throttle.
The MAX_INTERRUPTS is set to all throttle events.
The unthrottled could happen in 3 places.
- event/group sched. All events in the group are scheduled one by one.
All of them will be unthrottled eventually. Nothing needs to be
changed.
- The perf_adjust_freq_unthr_events for each tick. Needs to restart the
group altogether.
- The __perf_event_period(). The whole group needs to be restarted
altogether as well.
With the fix,
$ sudo perf report -D | grep PERF_RECORD_SAMPLE -a4 | tail -n 5
0 3573470770332 0x12f5f8 [0x70]: PERF_RECORD_SAMPLE(IP, 0x2):
... sample_read:
.... group nr 2
..... id 0000000000000a28, value 00000004fd3dfd8f, lost 0
..... id 0000000000000a29, value 00000004fd3dfd8f, lost 0
Suggested-by: "Peter Zijlstra (Intel)" <peterz@infradead.org>
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20250520181644.2673067-2-kan.liang@linux.intel.com
The kerneldoc for futex_wait_setup() states it can return "0" or "<1".
This isn't true because the error case is "<0" not less than 1.
Document that <0 is returned on error. Drop the possible return values
and state possible reasons.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: André Almeida <andrealmeid@igalia.com>
Link: https://lore.kernel.org/r/20250517151455.1065363-6-bigeasy@linutronix.de
The commit dfa0a574cb ("sched/uclamg: Handle delayed dequeue")
has add the sched_delayed check to prevent double uclamp_dec/inc.
However, it put the uclamp_rq_inc() after enqueue_task().
This may lead to the following issues:
When a task with uclamp goes through enqueue_task() and could trigger
cpufreq update, its uclamp won't even be considered in the cpufreq
update. It is only after enqueue will the uclamp be added to rq
buckets, and cpufreq will only pick it up at the next update.
This could cause a delay in frequency updating. It may affect
the performance(uclamp_min > 0) or power(uclamp_max < 1024).
So, just like util_est, put the uclamp_rq_inc() before enqueue_task().
And as for the sched_delayed_task, same as util_est, using the
sched_delayed flag to prevent inc the sched_delayed_task's uclamp,
using the ENQUEUE_DELAYED flag to allow inc the sched_delayed_task's uclamp
which is being woken up.
Signed-off-by: Xuewen Yan <xuewen.yan@unisoc.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>
Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Tested-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Link: https://lore.kernel.org/r/20250417043457.10632-3-xuewen.yan@unisoc.com
To prevent double enqueue/dequeue of the util-est for sched_delayed tasks,
commit 729288bc68 ("kernel/sched: Fix util_est accounting for DELAY_DEQUEUE")
added the corresponding check. This check excludes double en/dequeue during
task migration and priority changes.
In fact, these conditions can be simplified.
For util_est_dequeue, we know that sched_delayed flag is set in dequeue_entity.
When the task is sleeping, we need to call util_est_dequeue to subtract
util-est from the cfs_rq. At this point, sched_delayed has not yet been set.
If we find that sched_delayed is already set, it indicates that this task
has already called dequeue_task_fair once. In this case, there is no need to
call util_est_dequeue again. Therefore, simply checking the sched_delayed flag
should be sufficient to prevent unnecessary util_est updates during the dequeue.
For util_est_enqueue, our goal is to add the util_est to the cfs_rq
when task enqueue. However, we don't want to add the util_est of a
sched_delayed task to the cfs_rq because the task is sleeping.
Therefore, we can exclude the util_est_enqueue for sched_delayed tasks
by checking the sched_delayed flag. However, when waking up a delayed task,
the sched_delayed flag is cleared after util_est_enqueue. As a result,
if we only check the sched_delayed flag, we would miss the util_est_enqueue.
Since waking up a sched_delayed task calls enqueue_task with the ENQUEUE_DELAYED flag,
we can determine whether to call util_est_enqueue by checking if the
enqueue_flag contains ENQUEUE_DELAYED.
Signed-off-by: Xuewen Yan <xuewen.yan@unisoc.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>
Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Tested-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Link: https://lore.kernel.org/r/20250417043457.10632-2-xuewen.yan@unisoc.com
Delayed dequeued feature keeps a sleeping task enqueued until its
lag has elapsed. As a result, it stays also visible in rq->nr_running.
So when in wake_affine_idle(), we should use the real running-tasks
in rq to check whether we should place the wake-up task to
current cpu.
On the other hand, add a helper function to return the nr-delayed.
Fixes: 152e11f6df ("sched/fair: Implement delayed dequeue")
Signed-off-by: Xuewen Yan <xuewen.yan@unisoc.com>
Reviewed-and-tested-by: Tianchen Ding <dtcccc@linux.alibaba.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>
Link: https://lore.kernel.org/r/20250303105241.17251-2-xuewen.yan@unisoc.com
double-free bug in af_alg.
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Merge tag 'v6.15-p7' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6
Pull crypto fixes from Herbert Xu:
"This fixes a regression in padata as well as an ancient double-free
bug in af_alg"
* tag 'v6.15-p7' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
crypto: algif_hash - fix double free in hash_accept
padata: do not leak refcount in reorder_work
Allow scx_bpf_select_cpu_and() to be used from an unlocked context, in
addition to ops.enqueue() or ops.select_cpu().
This enables schedulers, including user-space ones, to implement a
consistent idle CPU selection policy and helps reduce code duplication.
Signed-off-by: Andrea Righi <arighi@nvidia.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Validate locking correctness when accessing p->nr_cpus_allowed and
p->cpus_ptr inside scx_bpf_select_cpu_and(): if the rq lock is held,
access is safe; otherwise, require that p->pi_lock is held.
This allows to catch potential unsafe calls to scx_bpf_select_cpu_and().
Signed-off-by: Andrea Righi <arighi@nvidia.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Relocate the scx_kf_allowed_if_unlocked(), so it can be used from other
source files (e.g., ext_idle.c).
No functional change.
Signed-off-by: Andrea Righi <arighi@nvidia.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
There are a few places where a conditional check is performed to validate a
given css on its rstat participation. This new helper tries to make the
code more readable where this check is performed.
Signed-off-by: JP Kobryn <inwardvessel@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
It is possible to eliminate contention between subsystems when
updating/flushing stats by using subsystem-specific locks. Let the existing
rstat locks be dedicated to the cgroup base stats and rename them to
reflect that. Add similar locks to the cgroup_subsys struct for use with
individual subsystems.
Lock initialization is done in the new function ss_rstat_init(ss) which
replaces cgroup_rstat_boot(void). If NULL is passed to this function, the
global base stat locks will be initialized. Otherwise, the subsystem locks
will be initialized.
Change the existing lock helper functions to accept a reference to a css.
Then within these functions, conditionally select the appropriate locks
based on the subsystem affiliation of the given css. Add helper functions
for this selection routine to avoid repeated code.
Signed-off-by: JP Kobryn <inwardvessel@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Different subsystems may call cgroup_rstat_updated() within the same
cgroup, resulting in a tree of pending updates from multiple subsystems.
When one of these subsystems is flushed via cgroup_rstat_flushed(), all
other subsystems with pending updates on the tree will also be flushed.
Change the paradigm of having a single rstat tree for all subsystems to
having separate trees for each subsystem. This separation allows for
subsystems to perform flushes without the side effects of other subsystems.
As an example, flushing the cpu stats will no longer cause the memory stats
to be flushed and vice versa.
In order to achieve subsystem-specific trees, change the tree node type
from cgroup to cgroup_subsys_state pointer. Then remove those pointers from
the cgroup and instead place them on the css. Finally, change update/flush
functions to make use of the different node type (css). These changes allow
a specific subsystem to be associated with an update or flush. Separate
rstat trees will now exist for each unique subsystem.
Since updating/flushing will now be done at the subsystem level, there is
no longer a need to keep track of updated css nodes at the cgroup level.
The list management of these nodes done within the cgroup (rstat_css_list
and related) has been removed accordingly.
Conditional guards for checking validity of a given css were placed within
css_rstat_updated/flush() to prevent undefined behavior occuring from kfunc
usage in bpf programs. Guards were also placed within css_rstat_init/exit()
in order to help consolidate calls to them. At call sites for all four
functions, the existing guards were removed.
Signed-off-by: JP Kobryn <inwardvessel@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Adjust the implementation of css_is_cgroup() so that it compares the given
css to cgroup::self. Rename the function to css_is_self() in order to
reflect that. Change the existing css->ss NULL check to a warning in the
true branch. Finally, adjust call sites to use the new function name.
Signed-off-by: JP Kobryn <inwardvessel@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
An early init subsystem that attempts to make use of rstat can lead to
failures during early boot. The reason for this is the timing in which the
css's of the root cgroup have css_online() invoked on them. At the point of
this call, there is a stated assumption that a cgroup has "successfully
completed all allocations" [0]. An example of a subsystem that relies on
the previously mentioned assumption [0] is the memory subsystem. Within its
implementation of css_online(), work is queued to asynchronously begin
flushing via rstat. In the early init path for a given subsystem, having
rstat enabled leads to this sequence:
cgroup_init_early()
for_each_subsys(ss, ssid)
if (ss->early_init)
cgroup_init_subsys(ss, true)
cgroup_init_subsys(ss, early_init)
css = ss->css_alloc(...)
init_and_link_css(css, ss, ...)
...
online_css(css)
online_css(css)
ss = css->ss
ss->css_online(css)
Continuing to use the memory subsystem as an example, the issue with this
sequence is that css_rstat_init() has not been called yet. This means there
is now a race between the pending async work to flush rstat and the call to
css_rstat_init(). So a flush can occur within the given cgroup while the
rstat fields are not initialized.
Since we are in the early init phase, the rstat fields cannot be
initialized because they require per-cpu allocations. So it's not possible
to have css_rstat_init() called early enough (before online_css()). This
patch treats the combination of early init and rstat the same as as other
invalid conditions.
[0] Documentation/admin-guide/cgroup-v1/cgroups.rst (section: css_online)
Signed-off-by: JP Kobryn <inwardvessel@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Throughout the verifier's logic, there are multiple checks for
inconsistent states that should never happen and would indicate a
verifier bug. These bugs are typically logged in the verifier logs and
sometimes preceded by a WARN_ONCE.
This patch reworks these checks to consistently emit a verifier log AND
a warning when CONFIG_DEBUG_KERNEL is enabled. The consistent use of
WARN_ONCE should help fuzzers (ex. syzkaller) expose any situation
where they are actually able to reach one of those buggy verifier
states.
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Paul Chaignon <paul.chaignon@gmail.com>
Link: https://lore.kernel.org/r/aCs1nYvNNMq8dAWP@mail.gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
A recent patch that addressed a UAF introduced a reference count leak:
the parallel_data refcount is incremented unconditionally, regardless
of the return value of queue_work(). If the work item is already queued,
the incremented refcount is never decremented.
Fix this by checking the return value of queue_work() and decrementing
the refcount when necessary.
Resolves:
Unreferenced object 0xffff9d9f421e3d80 (size 192):
comm "cryptomgr_probe", pid 157, jiffies 4294694003
hex dump (first 32 bytes):
80 8b cf 41 9f 9d ff ff b8 97 e0 89 ff ff ff ff ...A............
d0 97 e0 89 ff ff ff ff 19 00 00 00 1f 88 23 00 ..............#.
backtrace (crc 838fb36):
__kmalloc_cache_noprof+0x284/0x320
padata_alloc_pd+0x20/0x1e0
padata_alloc_shell+0x3b/0xa0
0xffffffffc040a54d
cryptomgr_probe+0x43/0xc0
kthread+0xf6/0x1f0
ret_from_fork+0x2f/0x50
ret_from_fork_asm+0x1a/0x30
Fixes: dd7d37ccf6 ("padata: avoid UAF for reorder_work")
Cc: <stable@vger.kernel.org>
Signed-off-by: Dominik Grzegorzek <dominik.grzegorzek@oracle.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The text_size bit referred to by the comment has been removed as of commit
ac3b432839 ("module: replace module_layout with module_memory")
and is thus no longer relevant. Remove it and comment about the contents of
the masks array instead.
Signed-off-by: Valentin Schneider <vschneid@redhat.com>
Link: https://lore.kernel.org/r/20250429113242.998312-23-vschneid@redhat.com
Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
Section .static_call_sites holds data structures that need to be sorted and
processed only at module load time. This initial processing happens in
static_call_add_module(), which is invoked as a callback to the
MODULE_STATE_COMING notification from prepare_coming_module().
The section is never modified afterwards. Make it therefore read-only after
module initialization to avoid any (non-)accidental modifications.
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Link: https://lore.kernel.org/r/20250306131430.7016-4-petr.pavlu@suse.com
Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
Move the logic to mark special sections as read-only after module
initialization into a separate function, along other related code in
strict_rwx.c. Use a table with names of such sections to make it easier to
add more.
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Link: https://lore.kernel.org/r/20250306131430.7016-3-petr.pavlu@suse.com
Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
Minor cleanup, this is a non-functional change.
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Link: https://lore.kernel.org/r/20250306131430.7016-2-petr.pavlu@suse.com
Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
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Merge tag 'mm-hotfixes-stable-2025-05-17-09-41' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull hotfixes from Andrew Morton:
"Nine singleton hotfixes, all MM. Four are cc:stable"
* tag 'mm-hotfixes-stable-2025-05-17-09-41' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
mm: userfaultfd: correct dirty flags set for both present and swap pte
zsmalloc: don't underflow size calculation in zs_obj_write()
mm/page_alloc: fix race condition in unaccepted memory handling
mm/page_alloc: ensure try_alloc_pages() plays well with unaccepted memory
MAINTAINERS: add mm GUP section
mm/codetag: move tag retrieval back upfront in __free_pages()
mm/memory: fix mapcount / refcount sanity check for mTHP reuse
kernel/fork: only call untrack_pfn_clear() on VMAs duplicated for fork()
mm: hugetlb: fix incorrect fallback for subpool
Add a helper to check if an event is in freq mode to improve readability.
No functional changes.
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20250516182853.2610284-2-kan.liang@linux.intel.com
`pr_cont()` unfortunately does not work here, as other parts of the
Linux kernel log between the two log lines:
[18445.295056] r8152-cfgselector 4-1.1.3: USB disconnect, device number 5
[18445.295112] OOM killer enabled.
[18445.295115] Restarting tasks ...
[18445.295185] usb 3-1: USB disconnect, device number 2
[18445.295193] usb 3-1.1: USB disconnect, device number 3
[18445.296262] usb 3-1.5: USB disconnect, device number 4
[18445.297017] done.
[18445.297029] random: crng reseeded on system resumption
`pr_cont()` also uses the default log level, normally warning, if the
corresponding log line is interrupted.
Therefore, replace the `pr_cont()`, and explicitly log it as a separate
line with log level info:
Restarting tasks: Starting
[…]
Restarting tasks: Done
Signed-off-by: Paul Menzel <pmenzel@molgen.mpg.de>
Link: https://patch.msgid.link/20250511174648.950430-1-pmenzel@molgen.mpg.de
[ rjw: Rebase on top of an earlier analogous change ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Creating an irq domain that serves as an MSI parent requires
a substantial amount of esoteric boiler-plate code, some of
which is often provided twice (such as the bus token).
To make things a bit simpler for the unsuspecting MSI tinkerer,
provide a helper that does it for them, and serves as documentation
of what needs to be provided.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20250513172819.2216709-3-maz@kernel.org
irqdomain.c's kernel-doc exists, but is not plugged into Documentation/
yet.
Before plugging it in, fix it first: irq_domain_get_irq_data() and
irq_domain_set_info() were documented twice. Identically, by both
definitions for CONFIG_IRQ_DOMAIN_HIERARCHY and !CONFIG_IRQ_DOMAIN_HIERARCHY.
Therefore, switch the second kernel-doc into an ordinary comment -- change
"/**" to simple "/*". This avoids sphinx's: WARNING: Duplicate C
declaration
Next, in commit b7b377332b ("irqdomain: Fix the kernel-doc and plug it
into Documentation"), irqdomain.h's (header) kernel-doc was added into
core-api/genericirq.rst. But given the amount of irqdomain functions and
structures, move all these to core-api/irq/irq-domain.rst now.
Finally, add these newly fixed irqdomain.c's (source) docs there as
well.
Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20250319092951.37667-58-jirislaby@kernel.org
Most irq_domain_add_*() functions are unused now, so drop them. The
remaining ones are moved to the deprecated section and will be removed
during the merge window after the patches in various trees have been
merged.
Note: The Chinese docs are touched but unfinished. I cannot parse those.
[ tglx: Remove the leftover in irq-domain.rst and handle merge logistics ]
Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20250319092951.37667-41-jirislaby@kernel.org
There is no reason to export the function as an extra symbol. It is
simple enough and is just a wrapper to already exported functions.
Therefore, switch the exported function to an inline.
Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20250319092951.37667-13-jirislaby@kernel.org
All uses of of_node_to_fwnode() in non-irqdomain code were changed to
"officially" defined of_fwnode_handle(). Therefore, the former can be
dropped along with the last uses in the irqdomain code.
Due to merge logistics the inline cannot be dropped immediately. Move it to
a deprecated section, which will be removed during the merge window.
[ tglx: Handle merge logistics ]
Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20250319092951.37667-12-jirislaby@kernel.org
Currently, the ->gpwrap is not tested (at all per my testing) due to the
requirement of a large delta between a CPU's rdp->gp_seq and its node's
rnp->gpseq.
This results in no testing of ->gpwrap being set. This patch by default
adds 5 minutes of testing with ->gpwrap forced by lowering the delta
between rdp->gp_seq and rnp->gp_seq to just 8 GPs. All of this is
configurable, including the active time for the setting and a full
testing cycle.
By default, the first 25 minutes of a test will have the _default_
behavior there is right now (ULONG_MAX / 4) delta. Then for 5 minutes,
we switch to a smaller delta causing 1-2 wraps in 5 minutes. I believe
this is reasonable since we at least add a little bit of testing for
usecases where ->gpwrap is set.
[ Apply fix for Dan Carpenter's bug report on init path cleanup. ]
[ Apply kernel doc warning fix from Akira Yokosawa. ]
Tested-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Joel Fernandes <joelagnelf@nvidia.com>
The rcu_torture_reader() and rcu_torture_fwd_prog_cr() functions
run CPU-bound for extended periods of time (tens or even
hundreds of milliseconds), so they invoke tick_dep_set_task() and
tick_dep_clear_task() to ensure that the scheduling-clock tick helps
move grace periods forward.
So why doesn't rcu_torture_fwd_prog_nr() also invoke tick_dep_set_task()
and tick_dep_clear_task()? Because the point of this function is to test
RCU's ability to (eventually) force grace periods forward even when the
tick has been disabled during long CPU-bound kernel execution.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Joel Fernandes <joelagnelf@nvidia.com>
For built with CONFIG_PROVE_RCU=y and CONFIG_PREEMPT_RT=y kernels,
Disable BH does not change the SOFTIRQ corresponding bits in
preempt_count(), but change current->softirq_disable_cnt, this
resulted in the following splat:
WARNING: suspicious RCU usage
kernel/rcu/tree_plugin.h:36 Unsafe read of RCU_NOCB offloaded state!
stack backtrace:
CPU: 0 UID: 0 PID: 22 Comm: rcuc/0
Call Trace:
[ 0.407907] <TASK>
[ 0.407910] dump_stack_lvl+0xbb/0xd0
[ 0.407917] dump_stack+0x14/0x20
[ 0.407920] lockdep_rcu_suspicious+0x133/0x210
[ 0.407932] rcu_rdp_is_offloaded+0x1c3/0x270
[ 0.407939] rcu_core+0x471/0x900
[ 0.407942] ? lockdep_hardirqs_on+0xd5/0x160
[ 0.407954] rcu_cpu_kthread+0x25f/0x870
[ 0.407959] ? __pfx_rcu_cpu_kthread+0x10/0x10
[ 0.407966] smpboot_thread_fn+0x34c/0xa50
[ 0.407970] ? trace_preempt_on+0x54/0x120
[ 0.407977] ? __pfx_smpboot_thread_fn+0x10/0x10
[ 0.407982] kthread+0x40e/0x840
[ 0.407990] ? __pfx_kthread+0x10/0x10
[ 0.407994] ? rt_spin_unlock+0x4e/0xb0
[ 0.407997] ? rt_spin_unlock+0x4e/0xb0
[ 0.408000] ? __pfx_kthread+0x10/0x10
[ 0.408006] ? __pfx_kthread+0x10/0x10
[ 0.408011] ret_from_fork+0x40/0x70
[ 0.408013] ? __pfx_kthread+0x10/0x10
[ 0.408018] ret_from_fork_asm+0x1a/0x30
[ 0.408042] </TASK>
Currently, triggering an rdp offloaded state change need the
corresponding rdp's CPU goes offline, and at this time the rcuc
kthreads has already in parking state. this means the corresponding
rcuc kthreads can safely read offloaded state of rdp while it's
corresponding cpu is online.
This commit therefore add softirq_count() check for
Preempt-RT kernels.
Suggested-by: Joel Fernandes <joelagnelf@nvidia.com>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Zqiang <qiang.zhang1211@gmail.com>
Signed-off-by: Joel Fernandes <joelagnelf@nvidia.com>
It's safer to using kcalloc() because it can prevent overflow
problem.
Reviewed-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Su Hui <suhui@nfschina.com>
Signed-off-by: Joel Fernandes <joelagnelf@nvidia.com>
This reverts commit f7345ccc62.
swake_up_one_online() has been removed because hrtimers can now assign
a proper online target to hrtimers queued from offline CPUs. Therefore
remove the related hackery.
Link: https://lore.kernel.org/all/20241231170712.149394-4-frederic@kernel.org/
Reviewed-by: Usama Arif <usamaarif642@gmail.com>
Reviewed-by: Joel Fernandes <joelagnelf@nvidia.com>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Joel Fernandes <joelagnelf@nvidia.com>
It's now ok to perform a wake-up from an offline CPU because the
resulting armed scheduler bandwidth hrtimers are now correctly targeted
by hrtimer infrastructure.
Remove the obsolete hackerry.
Link: https://lore.kernel.org/all/20241231170712.149394-3-frederic@kernel.org/
Reviewed-by: Usama Arif <usamaarif642@gmail.com>
Reviewed-by: Joel Fernandes <joelagnelf@nvidia.com>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Joel Fernandes <joelagnelf@nvidia.com>
Fix those:
./kernel/futex/futex.h:208: warning: Function parameter or struct member 'drop_hb_ref' not described in 'futex_q'
./kernel/futex/waitwake.c:343: warning: expecting prototype for futex_wait_queue(). Prototype was for futex_do_wait() instead
./kernel/futex/waitwake.c:594: warning: Function parameter or struct member 'task' not described in 'futex_wait_setup'
Fixes: 93f1b6d79a ("futex: Move futex_queue() into futex_wait_setup()")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20250512185641.0450a99b@canb.auug.org.au # report
Link: https://lore.kernel.org/r/20250515171641.24073-1-bp@kernel.org # submission
perf always allocates contiguous AUX pages based on aux_watermark.
However, this contiguous allocation doesn't benefit all PMUs. For
instance, ARM SPE and TRBE operate with virtual pages, and Coresight
ETR allocates a separate buffer. For these PMUs, allocating contiguous
AUX pages unnecessarily exacerbates memory fragmentation. This
fragmentation can prevent their use on long-running devices.
This patch modifies the perf driver to be memory-friendly by default,
by allocating non-contiguous AUX pages. For PMUs requiring contiguous
pages (Intel BTS and some Intel PT), the existing
PERF_PMU_CAP_AUX_NO_SG capability can be used. For PMUs that don't
require but can benefit from contiguous pages (some Intel PT), a new
capability, PERF_PMU_CAP_AUX_PREFER_LARGE, is added to maintain their
existing behavior.
Signed-off-by: Yabin Cui <yabinc@google.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: James Clark <james.clark@linaro.org>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20250508232642.148767-1-yabinc@google.com
Affinity-managed interrupts can be shut down and restarted during CPU
hotunplug/plug. Thereby the interrupt may be left in an unexpected state.
Specifically:
1. Interrupt is affine to CPU N
2. disable_irq() -> depth is 1
3. CPU N goes offline
4. irq_shutdown() -> depth is set to 1 (again)
5. CPU N goes online
6. irq_startup() -> depth is set to 0 (BUG! driver expects that the interrupt
still disabled)
7. enable_irq() -> depth underflow / unbalanced enable_irq() warning
This is only a problem for managed interrupts and CPU hotplug, all other
cases like request()/free()/request() truly needs to reset a possibly stale
disable depth value.
Provide a startup function, which takes the disable depth into account, and
invoked it for the managed interrupts in the CPU hotplug path.
This requires to change irq_shutdown() to do a depth increment instead of
setting it to 1, which allows to retain the disable depth, but is harmless
for the other code paths using irq_startup(), which will still reset the
disable depth unconditionally to keep the original correct behaviour.
A kunit tests will be added separately to cover some of these aspects.
[ tglx: Massaged changelog ]
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Brian Norris <briannorris@chromium.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20250514201353.3481400-2-briannorris@chromium.org
GCC is not happy about a sprintf() call on a buffer that might be too small
for the given formatting string.
kernel/irq/debugfs.c:233:26: warning: 'sprintf' may write a terminating nul past the end of the destination [-Wformat-overflow=]
Fix this by bumping the size of the local variable for sprintf().
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20250515085516.2913290-1-andriy.shevchenko@linux.intel.com
Closes: https://lore.kernel.org/oe-kbuild-all/202505151057.xbyXAbEn-lkp@intel.com/
- Add proper pahole version dependency to CONFIG_GENDWARFKSYMS to avoid
module loading errors
- Fix UAPI header tests for the OpenRISC architecture
- Add dependency on the libdw package in Debian and RPM packages
- Disable -Wdefault-const-init-unsafe warnings on Clang
- Make "make clean ARCH=um" also clean the arch/x86/ directory
- Revert the use of -fmacro-prefix-map=, which causes issues with
debugger usability
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Merge tag 'kbuild-fixes-v6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull Kbuild fixes from Masahiro Yamada:
- Add proper pahole version dependency to CONFIG_GENDWARFKSYMS to avoid
module loading errors
- Fix UAPI header tests for the OpenRISC architecture
- Add dependency on the libdw package in Debian and RPM packages
- Disable -Wdefault-const-init-unsafe warnings on Clang
- Make "make clean ARCH=um" also clean the arch/x86/ directory
- Revert the use of -fmacro-prefix-map=, which causes issues with
debugger usability
* tag 'kbuild-fixes-v6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
kbuild: fix typos "module.builtin" to "modules.builtin"
Revert "kbuild, rust: use -fremap-path-prefix to make paths relative"
Revert "kbuild: make all file references relative to source root"
kbuild: fix dependency on sorttable
init: remove unused CONFIG_CC_CAN_LINK_STATIC
um: let 'make clean' properly clean underlying SUBARCH as well
kbuild: Disable -Wdefault-const-init-unsafe
kbuild: rpm-pkg: Add (elfutils-devel or libdw-devel) to BuildRequires
kbuild: deb-pkg: Add libdw-dev:native to Build-Depends-Arch
usr/include: openrisc: don't HDRTEST bpf_perf_event.h
kbuild: Require pahole <v1.28 or >v1.29 with GENDWARFKSYMS on X86
There is currently some confusion in the s390x JIT regarding whether
orig_call can be NULL and what that means. Originally the NULL value
was used to distinguish the struct_ops case, but this was superseded by
BPF_TRAMP_F_INDIRECT (see commit 0c970ed2f8 ("s390/bpf: Fix indirect
trampoline generation").
The remaining reason to have this check is that NULL can actually be
passed to the arch_bpf_trampoline_size() call - but not to the
respective arch_prepare_bpf_trampoline()! call - by
bpf_struct_ops_prepare_trampoline().
Remove this asymmetry by passing stub_func to both functions, so that
JITs may rely on orig_call never being NULL.
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Acked-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/r/20250512221911.61314-2-iii@linux.ibm.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
- Fix sample code that uses trace_array_printk()
The sample code for in kernel use of trace_array (that creates an instance
for use within the kernel) and shows how to use trace_array_printk() that
writes into the created instance, used trace_printk_init_buffers(). But
that function is used to initialize normal trace_printk() and produces the
NOTICE banner which is not needed for use of trace_array_printk(). The
function to initialize that is trace_array_init_printk() that takes the
created trace array instance as a parameter.
Update the sample code to reflect the proper usage.
- Fix preemption count output for stacktrace event
The tracing buffer shows the preempt count level when an event executes.
Because writing the event itself disables preemption, this needs to be
accounted for when recording. The stacktrace event did not account for
this so the output of the stacktrace event showed preemption was disabled
while the event that triggered the stacktrace shows preemption is enabled
and this leads to confusion. Account for preemption being disabled for the
stacktrace event.
The same happened for stack traces triggered by function tracer.
- Fix persistent ring buffer when trace_pipe is used
The ring buffer swaps the reader page with the next page to read from the
write buffer when trace_pipe is used. If there's only a page of data in
the ring buffer, this swap will cause the "commit" pointer (last data
written) to be on the reader page. If more data is written to the buffer,
it is added to the reader page until it falls off back into the write
buffer.
If the system reboots and the commit pointer is still on the reader page,
even if new data was written, the persistent buffer validator will miss
finding the commit pointer because it only checks the write buffer and
does not check the reader page. This causes the validator to fail the
validation and clear the buffer, where the new data is lost.
There was a check for this, but it checked the "head pointer", which was
incorrect, because the "head pointer" always stays on the write buffer and
is the next page to swap out for the reader page. Fix the logic to catch
this case and allow the user to still read the data after reboot.
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Merge tag 'trace-v6.15-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull tracing fixes from Steven Rostedt:
- Fix sample code that uses trace_array_printk()
The sample code for in kernel use of trace_array (that creates an
instance for use within the kernel) and shows how to use
trace_array_printk() that writes into the created instance, used
trace_printk_init_buffers(). But that function is used to initialize
normal trace_printk() and produces the NOTICE banner which is not
needed for use of trace_array_printk(). The function to initialize
that is trace_array_init_printk() that takes the created trace array
instance as a parameter.
Update the sample code to reflect the proper usage.
- Fix preemption count output for stacktrace event
The tracing buffer shows the preempt count level when an event
executes. Because writing the event itself disables preemption, this
needs to be accounted for when recording. The stacktrace event did
not account for this so the output of the stacktrace event showed
preemption was disabled while the event that triggered the stacktrace
shows preemption is enabled and this leads to confusion. Account for
preemption being disabled for the stacktrace event.
The same happened for stack traces triggered by function tracer.
- Fix persistent ring buffer when trace_pipe is used
The ring buffer swaps the reader page with the next page to read from
the write buffer when trace_pipe is used. If there's only a page of
data in the ring buffer, this swap will cause the "commit" pointer
(last data written) to be on the reader page. If more data is written
to the buffer, it is added to the reader page until it falls off back
into the write buffer.
If the system reboots and the commit pointer is still on the reader
page, even if new data was written, the persistent buffer validator
will miss finding the commit pointer because it only checks the write
buffer and does not check the reader page. This causes the validator
to fail the validation and clear the buffer, where the new data is
lost.
There was a check for this, but it checked the "head pointer", which
was incorrect, because the "head pointer" always stays on the write
buffer and is the next page to swap out for the reader page. Fix the
logic to catch this case and allow the user to still read the data
after reboot.
* tag 'trace-v6.15-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
ring-buffer: Fix persistent buffer when commit page is the reader page
ftrace: Fix preemption accounting for stacktrace filter command
ftrace: Fix preemption accounting for stacktrace trigger command
tracing: samples: Initialize trace_array_printk() with the correct function
The ring buffer is made up of sub buffers (sometimes called pages as they
are by default PAGE_SIZE). It has the following "pages":
"tail page" - this is the page that the next write will write to
"head page" - this is the page that the reader will swap the reader page with.
"reader page" - This belongs to the reader, where it will swap the head
page from the ring buffer so that the reader does not
race with the writer.
The writer may end up on the "reader page" if the ring buffer hasn't
written more than one page, where the "tail page" and the "head page" are
the same.
The persistent ring buffer has meta data that points to where these pages
exist so on reboot it can re-create the pointers to the cpu_buffer
descriptor. But when the commit page is on the reader page, the logic is
incorrect.
The check to see if the commit page is on the reader page checked if the
head page was the reader page, which would never happen, as the head page
is always in the ring buffer. The correct check would be to test if the
commit page is on the reader page. If that's the case, then it can exit
out early as the commit page is only on the reader page when there's only
one page of data in the buffer. There's no reason to iterate the ring
buffer pages to find the "commit page" as it is already found.
To trigger this bug:
# echo 1 > /sys/kernel/tracing/instances/boot_mapped/events/syscalls/sys_enter_fchownat/enable
# touch /tmp/x
# chown sshd /tmp/x
# reboot
On boot up, the dmesg will have:
Ring buffer meta [0] is from previous boot!
Ring buffer meta [1] is from previous boot!
Ring buffer meta [2] is from previous boot!
Ring buffer meta [3] is from previous boot!
Ring buffer meta [4] commit page not found
Ring buffer meta [5] is from previous boot!
Ring buffer meta [6] is from previous boot!
Ring buffer meta [7] is from previous boot!
Where the buffer on CPU 4 had a "commit page not found" error and that
buffer is cleared and reset causing the output to be empty and the data lost.
When it works correctly, it has:
# cat /sys/kernel/tracing/instances/boot_mapped/trace_pipe
<...>-1137 [004] ..... 998.205323: sys_enter_fchownat: __syscall_nr=0x104 (260) dfd=0xffffff9c (4294967196) filename=(0xffffc90000a0002c) user=0x3e8 (1000) group=0xffffffff (4294967295) flag=0x0 (0
Cc: stable@vger.kernel.org
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20250513115032.3e0b97f7@gandalf.local.home
Fixes: 5f3b6e839f ("ring-buffer: Validate boot range memory events")
Reported-by: Tasos Sahanidis <tasos@tasossah.com>
Tested-by: Tasos Sahanidis <tasos@tasossah.com>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
When using the stacktrace trigger command to trace syscalls, the
preemption count was consistently reported as 1 when the system call
event itself had 0 (".").
For example:
root@ubuntu22-vm:/sys/kernel/tracing/events/syscalls/sys_enter_read
$ echo stacktrace > trigger
$ echo 1 > enable
sshd-416 [002] ..... 232.864910: sys_read(fd: a, buf: 556b1f3221d0, count: 8000)
sshd-416 [002] ...1. 232.864913: <stack trace>
=> ftrace_syscall_enter
=> syscall_trace_enter
=> do_syscall_64
=> entry_SYSCALL_64_after_hwframe
The root cause is that the trace framework disables preemption in __DO_TRACE before
invoking the trigger callback.
Use the tracing_gen_ctx_dec() that will accommodate for the increase of
the preemption count in __DO_TRACE when calling the callback. The result
is the accurate reporting of:
sshd-410 [004] ..... 210.117660: sys_read(fd: 4, buf: 559b725ba130, count: 40000)
sshd-410 [004] ..... 210.117662: <stack trace>
=> ftrace_syscall_enter
=> syscall_trace_enter
=> do_syscall_64
=> entry_SYSCALL_64_after_hwframe
Cc: stable@vger.kernel.org
Fixes: ce33c845b0 ("tracing: Dump stacktrace trigger to the corresponding instance")
Link: https://lore.kernel.org/20250512094246.1167956-1-dolinux.peng@gmail.com
Signed-off-by: pengdonglin <dolinux.peng@gmail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Naked scx_root dereferences are being used as temporary markers to indicate
that they need to be updated to point to the right scheduler instance.
Explain the situation.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Andrea Righi <arighi@nvidia.com>
Record trace_clock information in the trace_scratch area and recover
the trace_clock when boot, so that reader can docode the timestamp
correctly.
Note that since most trace_clocks records the timestamp in nano-
seconds, this is not a bug. But some trace_clock, like counter and
tsc will record the counter value. Only for those trace_clock user
needs this information.
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/174720625803.1925039.1815089037443798944.stgit@mhiramat.tok.corp.google.com
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Instead of find_first_bit() use the dedicated bitmap_empty(),
and make upper_empty() a nice one-liner.
While there, fix opencoded BITS_PER_TYPE().
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20250429195119.620204-1-yury.norov@gmail.com
Signed-off-by: Yury Norov <yury.norov@gmail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
In preparation of hierarchical scheduling support, add @sch to scx_exit()
and friends:
- scx_exit/error() updated to take explicit @sch instead of assuming
scx_root.
- scx_kf_exit/error() added. These are to be used from kfuncs, don't take
@sch and internally determine the scx_sched instance to abort. Currently,
it's always scx_root but once multiple scheduler support is in place, it
will be the scx_sched instance that invoked the kfunc. This simplifies
many callsites and defers scx_sched lookup until error is triggered.
- @sch is propagated to ops_cpu_valid() and ops_sanitize_err(). The CPU
validity conditions in ops_cpu_valid() are factored into __cpu_valid() to
implement kf_cpu_valid() which is the counterpart to scx_kf_exit/error().
- All users are converted. Most conversions are straightforward.
check_rq_for_timeouts() and scx_softlockup() are updated to use explicit
rcu_dereference*(scx_root) for safety as they may execute asynchronous to
the exit path. scx_tick() is also updated to use rcu_dereference(). While
not strictly necessary due to the preceding scx_enabled() test and IRQ
disabled context, this removes the subtlety at no noticeable cost.
No behavior changes intended.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Andrea Righi <arighi@nvidia.com>
__scx_exit() is the base exit implementation and there are three wrappers on
top of it - scx_exit(), __scx_error() and scx_error(). This is more
confusing than helpful especially given that there are only a couple users
of scx_exit() and __scx_error(). To simplify the situation:
- Make __scx_exit() take va_list and rename it to scx_vexit(). This is to
ease implementing more complex extensions on top.
- Make scx_exit() a varargs wrapper around __scx_exit(). scx_exit() now
takes both @kind and @exit_code.
- Convert existing scx_exit() and __scx_error() users to use the new
scx_exit().
- scx_error() remains unchanged.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Andrea Righi <arighi@nvidia.com>
In preparation of hierarchical scheduling support, make SCX_CALL_OP*() take
explicit @sch instead of assuming scx_root. As scx_root is still the only
scheduler instance, this patch doesn't make any functional changes.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Andrea Righi <arighi@nvidia.com>
- Always cache scx_root into local variable sch before using.
- Don't use scx_root if cached sch is available.
- Wrap !sch test with unlikely().
- Pass @scx into scx_cgroup_init/exit().
No behavior changes intended.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Andrea Righi <arighi@nvidia.com>
With the goal of deprecating / removing VOLUNTARY preempt, live-patch
needs to stop relying on cond_resched() to make forward progress.
Instead, rely on schedule() with TASK_FREEZABLE set. Just like
live-patching, the freezer needs to be able to stop tasks in a safe /
known state.
[bigeasy: use likely() in __klp_sched_try_switch() and update comments]
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Tested-by: Petr Mladek <pmladek@suse.com>
Tested-by: Miroslav Benes <mbenes@suse.cz>
Acked-by: Miroslav Benes <mbenes@suse.cz>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Link: https://lore.kernel.org/r/20250509113659.wkP_HJ5z@linutronix.de
Kindly inform the MSI driver that the domain is torn down, providing the
allocation context previously populated on domain creation.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20250513163144.2215824-5-maz@kernel.org
The current device MSI infrastructure is subtly broken, as it will issue an
.msi_prepare() callback into the MSI controller driver every time it needs
to allocate an MSI. That's pretty wrong, as the contract (or unwarranted
assumption, depending who you ask) between the MSI controller and the core
code is that .msi_prepare() is called exactly once per device.
This leads to some subtle breakage in some MSI controller drivers, as it
gives the impression that there are multiple endpoints sharing a bus
identifier (RID in PCI parlance, DID for GICv3+). It implies that whatever
allocation the ITS driver (for example) has done on behalf of these devices
cannot be undone, as there is no way to track the shared state. This is
particularly bad for wire-MSI devices, for which .msi_prepare() is called
for each input line.
To address this issue, move the call to .msi_prepare() to take place at the
point of irq domain allocation, which is the only place that makes
sense. The msi_alloc_info_t structure is made part of the
msi_domain_template, so that its life-cycle is that of the domain as well.
Finally, the msi_info::alloc_data field is made to point at this allocation
tracking structure, ensuring that it is carried around the block.
This is all pretty straightforward, except for the non-device-MSI
leftovers, which still have to call .msi_prepare() at the old spot. One
day...
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20250513163144.2215824-4-maz@kernel.org
The ITS driver currently nukes the structure representing an endpoint
device translating via an ITS on freeing the last LPI allocated for it.
That's an unfortunate state of affair, as it is pretty common for a driver
to allocate a single MSI, do something clever, teardown this MSI, and
reallocate a whole bunch of them. The NVME driver does exactly that,
amongst others.
What happens in that case is that the core code is accidentaly issuing
another .msi_prepare() call, even if it shouldn't. This luckily cancels
the above behaviour and hides the problem.
In order to fix the core code, start by implementing the new
.msi_teardown() callback. Nothing calls it yet, so a side effect is that
the its_dev structure will not be freed and that the DID will stay
mapped. Not a big deal, and this will be solved in following patches.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20250513163144.2215824-3-maz@kernel.org
While the MSI ops do have a .msi_prepare() callback that is responsible for
setting up the relevant (usually per-device) allocation, there is no
callback reversing this setup.
For this purpose, add .msi_teardown() callback.
In order to avoid breaking the ITS driver that suffers from related issues,
do not call the callback just yet.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20250513163144.2215824-2-maz@kernel.org
Commit 8589e325ba ("genirq/manage: Rework irq_set_irq_wake()") updated
the irq_set_irq_wake() to use the new guards for locking the interrupt
descriptor.
However, in doing so it inadvertently changed irq_set_irq_wake() such that
the 'chip_bus_lock' is no longer acquired. This has caused system suspend
tests to fail on some Tegra platforms.
Fix this by correcting the guard used in irq_set_irq_wake() to ensure the
'chip_bus_lock' is held.
Fixes: 8589e325ba ("genirq/manage: Rework irq_set_irq_wake()")
Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20250514095041.1109783-1-jonathanh@nvidia.com
Instead of hardcoding the list of kfuncs that need prog->aux passed to
them with a combination of fixup_kfunc_call adjustment + __ign suffix,
combine both in __prog suffix, which ignores the argument passed in, and
fixes it up to the prog->aux. This allows kfuncs to have the prog->aux
passed into them without having to touch the verifier.
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20250513142812.1021591-1-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The "suspend in progress" check in device_wakeup_enable() does not
cover hibernation, but arguably it should do that, so introduce
pm_sleep_transition_in_progress() covering transitions during both
system suspend and hibernation to use in there and use it also in
pm_debug_messages_should_print().
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Link: https://patch.msgid.link/7820474.EvYhyI6sBW@rjwysocki.net
[ rjw: Move the new function definition under CONFIG_PM_SLEEP ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
- fprobe: Fix RCU warning message in list traversal
fprobe_module_callback() using hlist_for_each_entry_rcu() traverse
the fprobe list but it locks fprobe_mutex() instead of rcu lock
because it is enough. So add lockdep_is_held() to avoid warning.
- tracing: eprobe: Add missing trace_probe_log_clear for eprobe
__trace_eprobe_create() uses trace_probe_log but forgot to clear
it at exit. Add trace_probe_log_clear() calls.
- tracing: probes: Fix possible race in trace_probe_log APIs
trace_probe_log APIs are used in probe event (dynamic_events,
kprobe_events and uprobe_events) creation. Only dynamic_events uses
the dyn_event_ops_mutex mutex to serialize it. This makes kprobe and
uprobe events to lock the same mutex to serialize its creation to
avoid race in trace_probe_log APIs.
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Merge tag 'probes-fixes-v6.15-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull probes fixes from Masami Hiramatsu:
- fprobe: Fix RCU warning message in list traversal
fprobe_module_callback() using hlist_for_each_entry_rcu() traverse
the fprobe list but it locks fprobe_mutex() instead of rcu lock
because it is enough. So add lockdep_is_held() to avoid warning.
- tracing: eprobe: Add missing trace_probe_log_clear for eprobe
__trace_eprobe_create() uses trace_probe_log but forgot to clear it
at exit. Add trace_probe_log_clear() calls.
- tracing: probes: Fix possible race in trace_probe_log APIs
trace_probe_log APIs are used in probe event (dynamic_events,
kprobe_events and uprobe_events) creation. Only dynamic_events uses
the dyn_event_ops_mutex mutex to serialize it. This makes kprobe and
uprobe events to lock the same mutex to serialize its creation to
avoid race in trace_probe_log APIs.
* tag 'probes-fixes-v6.15-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
tracing: probes: Fix a possible race in trace_probe_log APIs
tracing: add missing trace_probe_log_clear for eprobes
tracing: fprobe: Fix RCU warning message in list traversal
Right now, if the clocksource watchdog detects a clocksource skew, it might
perform a per CPU check, for example in the TSC case on x86. In other
words: supposing TSC is detected as unstable by the clocksource watchdog
running at CPU1, as part of marking TSC unstable the kernel will also run a
check of TSC readings on some CPUs to be sure it is synced between them
all.
But that check happens only on some CPUs, not all of them; this choice is
based on the parameter "verify_n_cpus" and in some random cpumask
calculation. So, the watchdog runs such per CPU checks on up to
"verify_n_cpus" random CPUs among all online CPUs, with the risk of
repeating CPUs (that aren't double checked) in the cpumask random
calculation.
But if "verify_n_cpus" > num_online_cpus(), it should skip the random
calculation and just go ahead and check the clocksource sync between
all online CPUs, without the risk of skipping some CPUs due to
duplicity in the random cpumask calculation.
Tests in a 4 CPU laptop with TSC skew detected led to some cases of the per
CPU verification skipping some CPU even with verify_n_cpus=8, due to the
duplicity on random cpumask generation. Skipping the randomization when the
number of online CPUs is smaller than verify_n_cpus, solves that.
Suggested-by: Thadeu Lima de Souza Cascardo <cascardo@igalia.com>
Signed-off-by: Guilherme G. Piccoli <gpiccoli@igalia.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Paul E. McKenney <paulmck@kernel.org>
Link: https://lore.kernel.org/all/20250323173857.372390-1-gpiccoli@igalia.com
Since the shared trace_probe_log variable can be accessed and
modified via probe event create operation of kprobe_events,
uprobe_events, and dynamic_events, it should be protected.
In the dynamic_events, all operations are serialized by
`dyn_event_ops_mutex`. But kprobe_events and uprobe_events
interfaces are not serialized.
To solve this issue, introduces dyn_event_create(), which runs
create() operation under the mutex, for kprobe_events and
uprobe_events. This also uses lockdep to check the mutex is
held when using trace_probe_log* APIs.
Link: https://lore.kernel.org/all/174684868120.551552.3068655787654268804.stgit@devnote2/
Reported-by: Paul Cacheux <paulcacheux@gmail.com>
Closes: https://lore.kernel.org/all/20250510074456.805a16872b591e2971a4d221@kernel.org/
Fixes: ab105a4fb8 ("tracing: Use tracing error_log with probe events")
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Add a function for updating the Energy Model for a CPU after its
capacity has changed, which subsequently will be used by the
intel_pstate driver.
An EM_PERF_DOMAIN_ARTIFICIAL check is added to em_recalc_and_update()
to prevent it from calling em_compute_costs() for an "artificial" perf
domain with a NULL cb parameter which would cause it to crash.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Tested-by: Christian Loehle <christian.loehle@arm.com>
Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Link: https://patch.msgid.link/3637203.iIbC2pHGDl@rjwysocki.net
Move the check of the CPU capacity currently stored in the energy model
against the arch_scale_cpu_capacity() value to em_adjust_new_capacity()
so it will be done regardless of where the latter is called from.
This will be useful when a new em_adjust_new_capacity() caller is added
subsequently.
While at it, move the pd local variable declaration in
em_check_capacity_update() into the loop in which it is used.
No intentional functional impact.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Tested-by: Christian Loehle <christian.loehle@arm.com>
Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Link: https://patch.msgid.link/7810787.EvYhyI6sBW@rjwysocki.net
Introduce pm_suspend_in_progress() to be used for checking if a system-
wide suspend or resume transition is in progress, instead of comparing
pm_suspend_target_state directly to PM_SUSPEND_ON, and use it where
applicable.
No intentional functional impact.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Acked-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: Raag Jadav <raag.jadav@intel.com>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Link: https://patch.msgid.link/2020901.PYKUYFuaPT@rjwysocki.net
Commit cdb8c100d8 ("include/linux/suspend.h: Only show pm_pr_dbg
messages at suspend/resume") caused PM debug messages to only be
printed during system-wide suspend and resume in progress, but it
forgot about hibernation.
Address this by adding a check for hibernation in progress to
pm_debug_messages_should_print().
Fixes: cdb8c100d8 ("include/linux/suspend.h: Only show pm_pr_dbg messages at suspend/resume")
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Link: https://patch.msgid.link/4998903.GXAFRqVoOG@rjwysocki.net
There are three cases in the genirq code when the irq, as an unsigned
integer variable, is converted to text representation by sprintf().
In two cases it uses '%d' specifier which is for signed values. While
it's not a problem right now, potentially it might be in the future
in case too big (> INT_MAX) number will appear there.
Consistently use '%u' format specifier for @irq which is declared as
unsigned int in all these cases.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20250509154643.1499171-1-andriy.shevchenko@linux.intel.com
After the conversion to locking guards within the interrupt core code,
several builds with clang show the "Interrupts were enabled early"
WARN() in start_kernel() on boot.
In class_irqdesc_lock_constructor(), _t.flags is initialized via
__irq_get_desc_lock() within the _t initializer list. However, the C11
standard 6.7.9.23 states that the evaluation of the initialization list
expressions are indeterminately sequenced relative to one another,
meaning _t.flags could be initialized by __irq_get_desc_lock() then be
initialized to zero due to flags being absent from the initializer list.
To ensure _t.flags is consistently initialized, move the call to
__irq_get_desc_lock() and the assignment of its result to _t.lock out of
the designated initializer.
Fixes: 0f70a49f3f ("genirq: Provide conditional lock guards")
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Link: https://lore.kernel.org/all/20250513-irq-guards-fix-flags-init-v1-1-1dca3f5992d6@kernel.org
Right now these are performed in kernel/fork.c which is odd and a
violation of separation of concerns, as well as preventing us from
integrating this and related logic into userland VMA testing going
forward.
There is a fly in the ointment - nommu - mmap.c is not compiled if
CONFIG_MMU not set, and neither is vma.c.
To square the circle, let's add a new file - vma_init.c. This will be
compiled for both CONFIG_MMU and nommu builds, and will also form part of
the VMA userland testing.
This allows us to de-duplicate code, while maintaining separation of
concerns and the ability for us to userland test this logic.
Update the VMA userland tests accordingly, additionally adding a
detach_free_vma() helper function to correctly detach VMAs before freeing
them in test code, as this change was triggering the assert for this.
[akpm@linux-foundation.org: remove stray newline, per Liam]
Link: https://lkml.kernel.org/r/f97b3a85a6da0196b28070df331b99e22b263be8.1745853549.git.lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Reviewed-by: Pedro Falcato <pfalcato@suse.de>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Kees Cook <kees@kernel.org>
Reviewed-by: Suren Baghdasaryan <surenb@google.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Jann Horn <jannh@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This is a key step in our being able to abstract and isolate VMA
allocation and destruction logic.
This function is the last one where vm_area_free() and vm_area_dup() are
directly referenced outside of mmap, so having this in mm allows us to
isolate these.
We do the same for the nommu version which is substantially simpler.
We place the declaration for dup_mmap() in mm/internal.h and have
kernel/fork.c import this in order to prevent improper use of this
functionality elsewhere in the kernel.
While we're here, we remove the useless #ifdef CONFIG_MMU check around
mmap_read_lock_maybe_expand() in mmap.c, mmap.c is compiled only if
CONFIG_MMU is set.
Link: https://lkml.kernel.org/r/e49aad3d00212f5539d9fa5769bfda4ce451db3e.1745853549.git.lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Suggested-by: Pedro Falcato <pfalcato@suse.de>
Reviewed-by: Pedro Falcato <pfalcato@suse.de>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Reviewed-by: Suren Baghdasaryan <surenb@google.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Kees Cook <kees@kernel.org>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Jann Horn <jannh@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "sched/numa: Skip VMA scanning on memory pinned to one NUMA
node via cpuset.mems", v5.
This patch (of 2):
When the memory of the current task is pinned to one NUMA node by cgroup,
there is no point in continuing the rest of VMA scanning and hinting page
faults as they will just be overhead. With this change, there will be no
more unnecessary PTE updates or page faults in this scenario.
We have seen up to a 6x improvement on a typical java workload running on
VMs with memory and CPU pinned to one NUMA node via cpuset in a two-socket
AARCH64 system. With the same pinning, on a 18-cores-per-socket Intel
platform, we have seen 20% improvment in a microbench that creates a
30-vCPU selftest KVM guest with 4GB memory, where each vCPU reads 4KB
pages in a fixed number of loops.
Link: https://lkml.kernel.org/r/20250424024523.2298272-1-libo.chen@oracle.com
Link: https://lkml.kernel.org/r/20250424024523.2298272-2-libo.chen@oracle.com
Signed-off-by: Libo Chen <libo.chen@oracle.com>
Tested-by: Chen Yu <yu.c.chen@intel.com>
Tested-by: Srikanth Aithal <sraithal@amd.com>
Tested-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Cc: "Chen, Tim C" <tim.c.chen@intel.com>
Cc: Chris Hyser <chris.hyser@oracle.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: K Prateek Nayak <kprateek.nayak@amd.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Madadi Vineeth Reddy <vineethr@linux.ibm.com>
Cc: Mel Gorman <mgorman <mgorman@suse.de>
Cc: Michal Koutný <mkoutny@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Raghavendra K T <raghavendra.kt@amd.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
We have all generic code in place now to support Kexec with KHO. This
patch adds a config option that depends on architecture support to enable
KHO support.
Link: https://lkml.kernel.org/r/20250509074635.3187114-9-changyuanl@google.com
Signed-off-by: Alexander Graf <graf@amazon.com>
Co-developed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Signed-off-by: Changyuan Lyu <changyuanl@google.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Anthony Yznaga <anthony.yznaga@oracle.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Ashish Kalra <ashish.kalra@amd.com>
Cc: Ben Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Betkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Gowans <jgowans@amazon.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Krzysztof Kozlowski <krzk@kernel.org>
Cc: Marc Rutland <mark.rutland@arm.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Pratyush Yadav <ptyadav@amazon.de>
Cc: Rob Herring <robh@kernel.org>
Cc: Saravana Kannan <saravanak@google.com>
Cc: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleinxer <tglx@linutronix.de>
Cc: Thomas Lendacky <thomas.lendacky@amd.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Kexec has 2 modes: A user space driven mode and a kernel driven mode. For
the kernel driven mode, kernel code determines the physical addresses of
all target buffers that the payload gets copied into.
With KHO, we can only safely copy payloads into the "scratch area". Teach
the kexec file loader about it, so it only allocates for that area. In
addition, enlighten it with support to ask the KHO subsystem for its
respective payloads to copy into target memory. Also teach the KHO
subsystem how to fill the images for file loads.
Link: https://lkml.kernel.org/r/20250509074635.3187114-8-changyuanl@google.com
Signed-off-by: Alexander Graf <graf@amazon.com>
Co-developed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Co-developed-by: Changyuan Lyu <changyuanl@google.com>
Signed-off-by: Changyuan Lyu <changyuanl@google.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Anthony Yznaga <anthony.yznaga@oracle.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Ashish Kalra <ashish.kalra@amd.com>
Cc: Ben Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Betkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Gowans <jgowans@amazon.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Krzysztof Kozlowski <krzk@kernel.org>
Cc: Marc Rutland <mark.rutland@arm.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Pratyush Yadav <ptyadav@amazon.de>
Cc: Rob Herring <robh@kernel.org>
Cc: Saravana Kannan <saravanak@google.com>
Cc: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleinxer <tglx@linutronix.de>
Cc: Thomas Lendacky <thomas.lendacky@amd.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Introduce APIs allowing KHO users to preserve memory across kexec and get
access to that memory after boot of the kexeced kernel
kho_preserve_folio() - record a folio to be preserved over kexec
kho_restore_folio() - recreates the folio from the preserved memory
kho_preserve_phys() - record physically contiguous range to be
preserved over kexec.
The memory preservations are tracked by two levels of xarrays to manage
chunks of per-order 512 byte bitmaps. For instance if PAGE_SIZE = 4096,
the entire 1G order of a 1TB x86 system would fit inside a single 512 byte
bitmap. For order 0 allocations each bitmap will cover 16M of address
space. Thus, for 16G of memory at most 512K of bitmap memory will be
needed for order 0.
At serialization time all bitmaps are recorded in a linked list of pages
for the next kernel to process and the physical address of the list is
recorded in KHO FDT.
The next kernel then processes that list, reserves the memory ranges and
later, when a user requests a folio or a physical range, KHO restores
corresponding memory map entries.
Link: https://lkml.kernel.org/r/20250509074635.3187114-7-changyuanl@google.com
Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Co-developed-by: Changyuan Lyu <changyuanl@google.com>
Signed-off-by: Changyuan Lyu <changyuanl@google.com>
Cc: Alexander Graf <graf@amazon.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Anthony Yznaga <anthony.yznaga@oracle.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Ashish Kalra <ashish.kalra@amd.com>
Cc: Ben Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Betkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Gowans <jgowans@amazon.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Krzysztof Kozlowski <krzk@kernel.org>
Cc: Marc Rutland <mark.rutland@arm.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Pratyush Yadav <ptyadav@amazon.de>
Cc: Rob Herring <robh@kernel.org>
Cc: Saravana Kannan <saravanak@google.com>
Cc: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleinxer <tglx@linutronix.de>
Cc: Thomas Lendacky <thomas.lendacky@amd.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
When we have a KHO kexec, we get an FDT blob and scratch region to
populate the state of the system. Provide helper functions that allow
architecture code to easily handle memory reservations based on them and
give device drivers visibility into the KHO FDT and memory reservations so
they can recover their own state.
Include a fix from Arnd Bergmann <arnd@arndb.de>
https://lore.kernel.org/lkml/20250424093302.3894961-1-arnd@kernel.org/.
Link: https://lkml.kernel.org/r/20250509074635.3187114-6-changyuanl@google.com
Signed-off-by: Alexander Graf <graf@amazon.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Co-developed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Co-developed-by: Changyuan Lyu <changyuanl@google.com>
Signed-off-by: Changyuan Lyu <changyuanl@google.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Anthony Yznaga <anthony.yznaga@oracle.com>
Cc: Ashish Kalra <ashish.kalra@amd.com>
Cc: Ben Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Betkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Gowans <jgowans@amazon.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Krzysztof Kozlowski <krzk@kernel.org>
Cc: Marc Rutland <mark.rutland@arm.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Pratyush Yadav <ptyadav@amazon.de>
Cc: Rob Herring <robh@kernel.org>
Cc: Saravana Kannan <saravanak@google.com>
Cc: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleinxer <tglx@linutronix.de>
Cc: Thomas Lendacky <thomas.lendacky@amd.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Add the infrastructure to generate Kexec HandOver metadata. Kexec
HandOver is a mechanism that allows Linux to preserve state - arbitrary
properties as well as memory locations - across kexec.
It does so using 2 concepts:
1) KHO FDT - Every KHO kexec carries a KHO specific flattened device tree
blob that describes preserved memory regions. Device drivers can
register to KHO to serialize and preserve their states before kexec.
2) Scratch Regions - CMA regions that we allocate in the first kernel.
CMA gives us the guarantee that no handover pages land in those
regions, because handover pages must be at a static physical memory
location. We use these regions as the place to load future kexec
images so that they won't collide with any handover data.
Link: https://lkml.kernel.org/r/20250509074635.3187114-5-changyuanl@google.com
Signed-off-by: Alexander Graf <graf@amazon.com>
Co-developed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Co-developed-by: Pratyush Yadav <ptyadav@amazon.de>
Signed-off-by: Pratyush Yadav <ptyadav@amazon.de>
Co-developed-by: Changyuan Lyu <changyuanl@google.com>
Signed-off-by: Changyuan Lyu <changyuanl@google.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Anthony Yznaga <anthony.yznaga@oracle.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Ashish Kalra <ashish.kalra@amd.com>
Cc: Ben Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Betkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Gowans <jgowans@amazon.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Krzysztof Kozlowski <krzk@kernel.org>
Cc: Marc Rutland <mark.rutland@arm.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rob Herring <robh@kernel.org>
Cc: Saravana Kannan <saravanak@google.com>
Cc: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleinxer <tglx@linutronix.de>
Cc: Thomas Lendacky <thomas.lendacky@amd.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
It is possible for a reclaimer to cause demotions of an lruvec belonging
to a cgroup with cpuset.mems set to exclude some nodes. Attempt to apply
this limitation based on the lruvec's memcg and prevent demotion.
Notably, this may still allow demotion of shared libraries or any memory
first instantiated in another cgroup. This means cpusets still cannot
cannot guarantee complete isolation when demotion is enabled, and the docs
have been updated to reflect this.
This is useful for isolating workloads on a multi-tenant system from
certain classes of memory more consistently - with the noted exceptions.
Note on locking:
The cgroup_get_e_css reference protects the css->effective_mems, and calls
of this interface would be subject to the same race conditions associated
with a non-atomic access to cs->effective_mems.
So while this interface cannot make strong guarantees of correctness, it
can therefore avoid taking a global or rcu_read_lock for performance.
Link: https://lkml.kernel.org/r/20250424202806.52632-3-gourry@gourry.net
Signed-off-by: Gregory Price <gourry@gourry.net>
Suggested-by: Shakeel Butt <shakeel.butt@linux.dev>
Suggested-by: Waiman Long <longman@redhat.com>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Shakeel Butt <shakeel.butt@linux.dev>
Reviewed-by: Waiman Long <longman@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Koutný <mkoutny@suse.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "vmscan: enforce mems_effective during demotion", v5.
Change reclaim to respect cpuset.mems_effective during demotion when
possible. Presently, reclaim explicitly ignores cpuset.mems_effective
when demoting, which may cause the cpuset settings to violated.
Implement cpuset_node_allowed() to check the cpuset.mems_effective
associated wih the mem_cgroup of the lruvec being scanned. This only
applies to cgroup/cpuset v2, as cpuset exists in a different hierarchy
than mem_cgroup in v1.
This requires renaming the existing cpuset_node_allowed() to be
cpuset_current_now_allowed() - which is more descriptive anyway - to
implement the new cpuset_node_allowed() which takes a target cgroup.
This patch (of 2):
Rename cpuset_node_allowed to reflect that the function checks the current
task's cpuset.mems. This allows us to make a new cpuset_node_allowed
function that checks a target cgroup's cpuset.mems.
Link: https://lkml.kernel.org/r/20250424202806.52632-1-gourry@gourry.net
Link: https://lkml.kernel.org/r/20250424202806.52632-2-gourry@gourry.net
Signed-off-by: Gregory Price <gourry@gourry.net>
Acked-by: Waiman Long <longman@redhat.com>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Koutný <mkoutny@suse.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This patch introduces a new set of kfuncs for working with dynptrs in
BPF programs, enabling reading variable-length user or kernel data
into dynptr directly. To enable memory-safety, verifier allows only
constant-sized reads via existing bpf_probe_read_{user|kernel} etc.
kfuncs, dynptr-based kfuncs allow dynamically-sized reads without memory
safety shortcomings.
The following kfuncs are introduced:
* `bpf_probe_read_kernel_dynptr()`: probes kernel-space data into a dynptr
* `bpf_probe_read_user_dynptr()`: probes user-space data into a dynptr
* `bpf_probe_read_kernel_str_dynptr()`: probes kernel-space string into
a dynptr
* `bpf_probe_read_user_str_dynptr()`: probes user-space string into a
dynptr
* `bpf_copy_from_user_dynptr()`: sleepable, copies user-space data into
a dynptr for the current task
* `bpf_copy_from_user_str_dynptr()`: sleepable, copies user-space string
into a dynptr for the current task
* `bpf_copy_from_user_task_dynptr()`: sleepable, copies user-space data
of the task into a dynptr
* `bpf_copy_from_user_task_str_dynptr()`: sleepable, copies user-space
string of the task into a dynptr
The implementation is built on two generic functions:
* __bpf_dynptr_copy
* __bpf_dynptr_copy_str
These functions take function pointers as arguments, enabling the
copying of data from various sources, including both kernel and user
space.
Use __always_inline for generic functions and callbacks to make sure the
compiler doesn't generate indirect calls into callbacks, which is more
expensive, especially on some kernel configurations. Inlining allows
compiler to put direct calls into all the specific callback implementations
(copy_user_data_sleepable, copy_user_data_nofault, and so on).
Reviewed-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Link: https://lore.kernel.org/r/20250512205348.191079-3-mykyta.yatsenko5@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Make bpf_dynptr_slice_rdwr, bpf_dynptr_check_off_len and
__bpf_dynptr_write available outside of the helpers.c by
adding their prototypes into linux/include/bpf.h.
bpf_dynptr_check_off_len() implementation is moved to header and made
inline explicitly, as small function should typically be inlined.
These functions are going to be used from bpf_trace.c in the next
patch of this series.
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Link: https://lore.kernel.org/r/20250512205348.191079-2-mykyta.yatsenko5@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
A little bit invasive for rc6 but they're important fixes, pass tests fine
and won't break anything outside sched_ext.
- scx_bpf_cpuperf_set() calls internal functions that require the rq to be
locked. It assumed that the BPF caller has rq locked but that's not always
true. Fix it by tracking whether rq is currently held by the CPU and
grabbing it if necessary.
- bpf_iter_scx_dsq_new() was leaving the DSQ iterator in an uninitialized
state after an error. However, next() and destroy() can be called on an
iterator which failed initialization and thus they always need to be
initialized even after an init error. Fix by always initializing the
iterator.
- Remove duplicate BTF_ID_FLAGS() entries.
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Merge tag 'sched_ext-for-6.15-rc6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext
Pull sched_ext fixes from Tejun Heo:
"A little bit invasive for rc6 but they're important fixes, pass tests
fine and won't break anything outside sched_ext:
- scx_bpf_cpuperf_set() calls internal functions that require the rq
to be locked. It assumed that the BPF caller has rq locked but
that's not always true. Fix it by tracking whether rq is currently
held by the CPU and grabbing it if necessary
- bpf_iter_scx_dsq_new() was leaving the DSQ iterator in an
uninitialized state after an error. However, next() and destroy()
can be called on an iterator which failed initialization and thus
they always need to be initialized even after an init error. Fix by
always initializing the iterator
- Remove duplicate BTF_ID_FLAGS() entries"
* tag 'sched_ext-for-6.15-rc6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext:
sched_ext: bpf_iter_scx_dsq_new() should always initialize iterator
sched_ext: Fix rq lock state in hotplug ops
sched_ext: Remove duplicate BTF_ID_FLAGS definitions
sched_ext: Fix missing rq lock in scx_bpf_cpuperf_set()
sched_ext: Track currently locked rq
One low-risk patch to fix a cpuset bug where it over-eagerly tries to modify
CPU affinity of kernel threads.
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Merge tag 'cgroup-for-6.15-rc6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup fix from Tejun Heo:
"One low-risk patch to fix a cpuset bug where it over-eagerly tries to
modify CPU affinity of kernel threads"
* tag 'cgroup-for-6.15-rc6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
cgroup/cpuset: Extend kthread_is_per_cpu() check to all PF_NO_SETAFFINITY tasks
With CONFIG_GENDWARFKSYMS, __gendwarfksyms_ptr variables are
added to the kernel in EXPORT_SYMBOL() to ensure DWARF type
information is available for exported symbols in the TUs where
they're actually exported. These symbols are dropped when linking
vmlinux, but dangling references to them remain in DWARF.
With CONFIG_DEBUG_INFO_BTF enabled on X86, pahole versions after
commit 47dcb534e253 ("btf_encoder: Stop indexing symbols for
VARs") and before commit 9810758003ce ("btf_encoder: Verify 0
address DWARF variables are in ELF section") place these symbols
in the .data..percpu section, which results in an "Invalid
offset" error in btf_datasec_check_meta() during boot, as all
the variables are at zero offset and have non-zero size. If
CONFIG_DEBUG_INFO_BTF_MODULES is enabled, this also results in a
failure to load modules with:
failed to validate module [$module] BTF: -22
As the issue occurs in pahole v1.28 and the fix was merged
after v1.29 was released, require pahole <v1.28 or >v1.29 when
GENDWARFKSYMS is enabled with DEBUG_INFO_BTF on X86.
Reported-by: Paolo Pisati <paolo.pisati@canonical.com>
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
This user of SHA-256 does not support any other algorithm, so the
crypto_shash abstraction provides no value. Just use the SHA-256 library
API instead, which is much simpler and easier to use.
Tested with '/sbin/kexec --kexec-file-syscall'.
Link: https://lkml.kernel.org/r/20250428185721.844686-1-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Dave Young <dyoung@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
When updating `watchdog_thresh`, there is a race condition between writing
the new `watchdog_thresh` value and stopping the old watchdog timer. If
the old timer triggers during this window, it may falsely detect a
softlockup due to the old interval and the new `watchdog_thresh` value
being used. The problem can be described as follow:
# We asuume previous watchdog_thresh is 60, so the watchdog timer is
# coming every 24s.
echo 10 > /proc/sys/kernel/watchdog_thresh (User space)
|
+------>+ update watchdog_thresh (We are in kernel now)
|
| # using old interval and new `watchdog_thresh`
+------>+ watchdog hrtimer (irq context: detect softlockup)
|
|
+-------+
|
|
+ softlockup_stop_all
To fix this problem, introduce a shadow variable for `watchdog_thresh`.
The update to the actual `watchdog_thresh` is delayed until after the old
timer is stopped, preventing false positives.
The following testcase may help to understand this problem.
---------------------------------------------
echo RT_RUNTIME_SHARE > /sys/kernel/debug/sched/features
echo -1 > /proc/sys/kernel/sched_rt_runtime_us
echo 0 > /sys/kernel/debug/sched/fair_server/cpu3/runtime
echo 60 > /proc/sys/kernel/watchdog_thresh
taskset -c 3 chrt -r 99 /bin/bash -c "while true;do true; done" &
echo 10 > /proc/sys/kernel/watchdog_thresh &
---------------------------------------------
The test case above first removes the throttling restrictions for
real-time tasks. It then sets watchdog_thresh to 60 and executes a
real-time task ,a simple while(1) loop, on cpu3. Consequently, the final
command gets blocked because the presence of this real-time thread
prevents kworker:3 from being selected by the scheduler. This eventually
triggers a softlockup detection on cpu3 due to watchdog_timer_fn operating
with inconsistent variable - using both the old interval and the updated
watchdog_thresh simultaneously.
[nysal@linux.ibm.com: fix the SOFTLOCKUP_DETECTOR=n case]
Link: https://lkml.kernel.org/r/20250502111120.282690-1-nysal@linux.ibm.com
Link: https://lkml.kernel.org/r/20250421035021.3507649-1-luogengkun@huaweicloud.com
Signed-off-by: Luo Gengkun <luogengkun@huaweicloud.com>
Signed-off-by: Nysal Jan K.A. <nysal@linux.ibm.com>
Cc: Doug Anderson <dianders@chromium.org>
Cc: Joel Granados <joel.granados@kernel.org>
Cc: Song Liu <song@kernel.org>
Cc: Thomas Gleinxer <tglx@linutronix.de>
Cc: "Nysal Jan K.A." <nysal@linux.ibm.com>
Cc: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
There is a spelling mistake in a pr_warn message. Fix it.
Link: https://lkml.kernel.org/r/20250418120331.535086-1-colin.i.king@gmail.com
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Acked-by: Baoquan He <bhe@redhat.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The last use of relay_late_setup_files() was removed in 2018 by commit
2b47733045 ("drm/i915/guc: Merge log relay file and channel creation")
Remove it and the helper it used.
relay_late_setup_files() was used for eventually registering 'buffer only'
channels. With it gone, delete the docs that explain how to do that.
Which suggests it should be possible to lose the 'has_base_filename'
flags.
(Are there any other uses??)
Link: https://lkml.kernel.org/r/20250418234932.490863-1-linux@treblig.org
Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andriy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This reduces single-threaded overhead as it avoids one lock+irq trip on
exit.
It also improves scalability of spawning and killing threads within one
process (just shy of 5% when doing it on 24 cores on my test jig).
Both routines are moved below kcov and kmsan exit, which should be
harmless.
Link: https://lkml.kernel.org/r/20250319195436.1864415-1-mjguzik@gmail.com
Signed-off-by: Mateusz Guzik <mjguzik@gmail.com>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
On Intel TDX guest, unaccepted memory is unusable free memory which is not
managed by buddy, until it's accepted by guest. Before that, it cannot be
accessed by the first kernel as well as the kexec'ed kernel. The kexec'ed
kernel will skip these pages and fill in zero data for the reader of
vmcore.
The dump tool like makedumpfile creates a page descriptor (size 24 bytes)
for each non-free page, including zero data page, but it will not create
descriptor for free pages. If it is not able to distinguish these
unaccepted pages with zero data pages, a certain amount of space will be
wasted in proportion (~1/170). In fact, as a special kind of free page
the unaccepted pages should be excluded, like the real free pages.
Export the page type PAGE_UNACCEPTED_MAPCOUNT_VALUE to vmcoreinfo, so that
dump tool can identify whether a page is unaccepted.
[zhiquan1.li@intel.com: fix docs: "Title underline too short" warning]
Link: https://lore.kernel.org/all/20240809114854.3745464-5-kirill.shutemov@linux.intel.com/
Link: https://lkml.kernel.org/r/20250405060610.860465-1-zhiquan1.li@intel.com
Link: https://lore.kernel.org/all/20240809114854.3745464-5-kirill.shutemov@linux.intel.com/
Link: https://lkml.kernel.org/r/20250403030801.758687-1-zhiquan1.li@intel.com
Signed-off-by: Zhiquan Li <zhiquan1.li@intel.com>
Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Baoquan He <bhe@redhat.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Zhiquan Li <zhiquan1.li@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
It is useful to be able to access current->mm at task exit to, say, record
a bunch of VMA information right before the task exits (e.g., for stack
symbolization reasons when dealing with short-lived processes that exit in
the middle of profiling session). Currently, trace_sched_process_exit()
is triggered after exit_mm() which resets current->mm to NULL making this
tracepoint unsuitable for inspecting and recording task's
mm_struct-related data when tracing process lifetimes.
There is a particularly suitable place, though, right after
taskstats_exit() is called, but before we do exit_mm() and other exit_*()
resource teardowns. taskstats performs a similar kind of accounting that
some applications do with BPF, and so co-locating them seems like a good
fit. So that's where trace_sched_process_exit() is moved with this patch.
Also, existing trace_sched_process_exit() tracepoint is notoriously
missing `group_dead` flag that is certainly useful in practice and some of
our production applications have to work around this. So plumb
`group_dead` through while at it, to have a richer and more complete
tracepoint.
Note that we can't use sched_process_template anymore, and so we use
TRACE_EVENT()-based tracepoint definition. But all the field names and
order, as well as assign and output logic remain intact. We just add one
extra field at the end in backwards-compatible way.
[andrii@kernel.org: document sched_process_exit and sched_process_template relation]
Link: https://lkml.kernel.org/r/20250403174120.4087794-1-andrii@kernel.org
Link: https://lkml.kernel.org/r/20250402180925.90914-1-andrii@kernel.org
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Suggested-by: Ingo Molnar <mingo@kernel.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
uprobe_write_opcode() does some pretty low-level things that really, it
shouldn't be doing: for example, manually breaking COW by allocating
anonymous folios and replacing mapped pages.
Further, it does seem to do some shaky things: for example, writing to
possible COW-shared anonymous pages or zapping anonymous pages that might
be pinned. We're also not taking care of uffd, uffd-wp, softdirty ...
although rather corner cases here. Let's just get it right like ordinary
ptrace writes would.
Let's rewrite the code, leaving COW-breaking to core-MM, triggered by
FOLL_FORCE|FOLL_WRITE (note that the code was already using FOLL_FORCE).
We'll use GUP to lookup/faultin the page and break COW if required. Then,
we'll walk the page tables using a folio_walk to perform our page
modification atomically by temporarily unmap the PTE + flushing the TLB.
Likely, we could avoid the temporary unmap in case we can just atomically
write the instruction, but that will be a separate project.
Unfortunately, we still have to implement the zapping logic manually,
because we only want to zap in specific circumstances (e.g., page content
identical).
Note that we can now handle large folios (compound pages) and the shared
zeropage just fine, so drop these checks.
Link: https://lkml.kernel.org/r/20250321113713.204682-4-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <olsajiri@gmail.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Namhyung kim <namhyung@kernel.org>
Cc: Russel King <linux@armlinux.org.uk>
Cc: tongtiangen <tongtiangen@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
We already have the VMA, no need to look it up using
get_user_page_vma_remote(). We can now switch to get_user_pages_remote().
Link: https://lkml.kernel.org/r/20250321113713.204682-3-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <olsajiri@gmail.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Namhyung kim <namhyung@kernel.org>
Cc: Russel King <linux@armlinux.org.uk>
Cc: tongtiangen <tongtiangen@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "kernel/events/uprobes: uprobe_write_opcode() rewrite", v3.
Currently, uprobe_write_opcode() implements COW-breaking manually, which
is really far from ideal. Further, there is interest in supporting
uprobes on hugetlb pages [1], and leaving at least the COW-breaking to the
core will make this much easier.
Also, I think the current code doesn't really handle some things properly
(see patch #3) when replacing/zapping pages.
Let's rewrite it, to leave COW-breaking to the fault handler, and handle
registration/unregistration by temporarily unmapping the anonymous page,
modifying it, and mapping it again. We still have to implement zapping of
anonymous pages ourselves, unfortunately.
We could look into not performing the temporary unmapping if we can
perform the write atomically, which would likely also make adding hugetlb
support a lot easier. But, limited (e.g., only PMD/PUD) hugetlb support
could be added on top of this with some tweaking.
Note that we now won't have to allocate another anonymous folio when
unregistering (which will be beneficial for hugetlb as well), we can
simply modify the already-mapped one from the registration (if any). When
registering a uprobe, we'll first trigger a ptrace-like write fault to
break COW, to then modify the already-mapped page.
Briefly sanity tested with perf probes and with the bpf uprobes selftest.
This patch (of 3):
Pass VMA instead of MM to remove_breakpoint() and remove the "MM" argument
from install_breakpoint(), because it can easily be derived from the VMA.
Link: https://lkml.kernel.org/r/20250321113713.204682-1-david@redhat.com
Link: https://lkml.kernel.org/r/20250321113713.204682-2-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Jiri Olsa <olsajiri@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Namhyung kim <namhyung@kernel.org>
Cc: Russel King <linux@armlinux.org.uk>
Cc: tongtiangen <tongtiangen@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
PTRACE_SET_SYSCALL_INFO is a generic ptrace API that complements
PTRACE_GET_SYSCALL_INFO by letting the ptracer modify details of system
calls the tracee is blocked in.
This API allows ptracers to obtain and modify system call details in a
straightforward and architecture-agnostic way, providing a consistent way
of manipulating the system call number and arguments across architectures.
As in case of PTRACE_GET_SYSCALL_INFO, PTRACE_SET_SYSCALL_INFO also does
not aim to address numerous architecture-specific system call ABI
peculiarities, like differences in the number of system call arguments for
such system calls as pread64 and preadv.
The current implementation supports changing only those bits of system
call information that are used by strace system call tampering, namely,
syscall number, syscall arguments, and syscall return value.
Support of changing additional details returned by
PTRACE_GET_SYSCALL_INFO, such as instruction pointer and stack pointer,
could be added later if needed, by using struct ptrace_syscall_info.flags
to specify the additional details that should be set. Currently, "flags"
and "reserved" fields of struct ptrace_syscall_info must be initialized
with zeroes; "arch", "instruction_pointer", and "stack_pointer" fields are
currently ignored.
PTRACE_SET_SYSCALL_INFO currently supports only PTRACE_SYSCALL_INFO_ENTRY,
PTRACE_SYSCALL_INFO_EXIT, and PTRACE_SYSCALL_INFO_SECCOMP operations.
Other operations could be added later if needed.
Ideally, PTRACE_SET_SYSCALL_INFO should have been introduced along with
PTRACE_GET_SYSCALL_INFO, but it didn't happen. The last straw that
convinced me to implement PTRACE_SET_SYSCALL_INFO was apparent failure to
provide an API of changing the first system call argument on riscv
architecture.
ptrace(2) man page:
long ptrace(enum __ptrace_request request, pid_t pid, void *addr, void *data);
...
PTRACE_SET_SYSCALL_INFO
Modify information about the system call that caused the stop.
The "data" argument is a pointer to struct ptrace_syscall_info
that specifies the system call information to be set.
The "addr" argument should be set to sizeof(struct ptrace_syscall_info)).
Link: https://lore.kernel.org/all/59505464-c84a-403d-972f-d4b2055eeaac@gmail.com/
Link: https://lkml.kernel.org/r/20250303112044.GF24170@strace.io
Signed-off-by: Dmitry V. Levin <ldv@strace.io>
Reviewed-by: Alexey Gladkov <legion@kernel.org>
Reviewed-by: Charlie Jenkins <charlie@rivosinc.com>
Tested-by: Charlie Jenkins <charlie@rivosinc.com>
Reviewed-by: Eugene Syromiatnikov <esyr@redhat.com>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Andreas Larsson <andreas@gaisler.com>
Cc: anton ivanov <anton.ivanov@cambridgegreys.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Betkov <bp@alien8.de>
Cc: Brian Cain <bcain@quicinc.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christian Zankel <chris@zankel.net>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Davide Berardi <berardi.dav@gmail.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Dinh Nguyen <dinguyen@kernel.org>
Cc: Eugene Syromyatnikov <evgsyr@gmail.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Guo Ren <guoren@kernel.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Maciej W. Rozycki <macro@orcam.me.uk>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: Naveen N Rao <naveen@kernel.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Renzo Davoi <renzo@cs.unibo.it>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Russel King <linux@armlinux.org.uk>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Thomas Gleinxer <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vineet Gupta <vgupta@kernel.org>
Cc: WANG Xuerui <kernel@xen0n.name>
Cc: Will Deacon <will@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Move the code that calculates the type of the system call stop out of
ptrace_get_syscall_info() into a separate function
ptrace_get_syscall_info_op() which is going to be used later to implement
PTRACE_SET_SYSCALL_INFO API.
Link: https://lkml.kernel.org/r/20250303112038.GE24170@strace.io
Signed-off-by: Dmitry V. Levin <ldv@strace.io>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Alexey Gladkov (Intel) <legion@kernel.org>
Cc: Andreas Larsson <andreas@gaisler.com>
Cc: anton ivanov <anton.ivanov@cambridgegreys.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Betkov <bp@alien8.de>
Cc: Brian Cain <bcain@quicinc.com>
Cc: Charlie Jenkins <charlie@rivosinc.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christian Zankel <chris@zankel.net>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Davide Berardi <berardi.dav@gmail.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Dinh Nguyen <dinguyen@kernel.org>
Cc: Eugene Syromiatnikov <esyr@redhat.com>
Cc: Eugene Syromyatnikov <evgsyr@gmail.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Guo Ren <guoren@kernel.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Maciej W. Rozycki <macro@orcam.me.uk>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: Naveen N Rao <naveen@kernel.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Renzo Davoi <renzo@cs.unibo.it>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Russel King <linux@armlinux.org.uk>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Thomas Gleinxer <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vineet Gupta <vgupta@kernel.org>
Cc: WANG Xuerui <kernel@xen0n.name>
Cc: Will Deacon <will@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Not intuitive, but vm_area_dup() located in kernel/fork.c is not only used
for duplicating VMAs during fork(), but also for duplicating VMAs when
splitting VMAs or when mremap()'ing them.
VM_PFNMAP mappings can at least get ordinarily mremap()'ed (no change in
size) and apparently also shrunk during mremap(), which implies
duplicating the VMA in __split_vma() first.
In case of ordinary mremap() (no change in size), we first duplicate the
VMA in copy_vma_and_data()->copy_vma() to then call untrack_pfn_clear() on
the old VMA: we effectively move the VM_PAT reservation. So the
untrack_pfn_clear() call on the new VMA duplicating is wrong in that
context.
Splitting of VMAs seems problematic, because we don't duplicate/adjust the
reservation when splitting the VMA. Instead, in memtype_erase() -- called
during zapping/munmap -- we shrink a reservation in case only the end
address matches: Assume we split a VMA into A and B, both would share a
reservation until B is unmapped.
So when unmapping B, the reservation would be updated to cover only A.
When unmapping A, we would properly remove the now-shrunk reservation.
That scenario describes the mremap() shrinking (old_size > new_size),
where we split + unmap B, and the untrack_pfn_clear() on the new VMA when
is wrong.
What if we manage to split a VM_PFNMAP VMA into A and B and unmap A first?
It would be broken because we would never free the reservation. Likely,
there are ways to trigger such a VMA split outside of mremap().
Affecting other VMA duplication was not intended, vm_area_dup() being used
outside of kernel/fork.c was an oversight. So let's fix that for; how to
handle VMA splits better should be investigated separately.
With a simple reproducer that uses mprotect() to split such a VMA I can
trigger
x86/PAT: pat_mremap:26448 freeing invalid memtype [mem 0x00000000-0x00000fff]
Link: https://lkml.kernel.org/r/20250422144942.2871395-1-david@redhat.com
Fixes: dc84bc2aba ("x86/mm/pat: Fix VM_PAT handling when fork() fails in copy_page_range()")
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Rik van Riel <riel@surriel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
- Fix time keeping bugs in CLOCK_MONOTONIC_COARSE clocks
- Work around absolute relocations into vDSO code that
GCC erroneously emits in certain arm64 build environments
- Fix a false positive lockdep warning in the i8253 clocksource
driver
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'timers-urgent-2025-05-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull misc timers fixes from Ingo Molnar:
- Fix time keeping bugs in CLOCK_MONOTONIC_COARSE clocks
- Work around absolute relocations into vDSO code that GCC erroneously
emits in certain arm64 build environments
- Fix a false positive lockdep warning in the i8253 clocksource driver
* tag 'timers-urgent-2025-05-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
clocksource/i8253: Use raw_spinlock_irqsave() in clockevent_i8253_disable()
arm64: vdso: Work around invalid absolute relocations from GCC
timekeeping: Prevent coarse clocks going backwards
Make sure trace_probe_log_clear is called in the tracing
eprobe code path, matching the trace_probe_log_init call.
Link: https://lore.kernel.org/all/20250504-fix-trace-probe-log-race-v3-1-9e99fec7eddc@gmail.com/
Signed-off-by: Paul Cacheux <paulcacheux@gmail.com>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
When CONFIG_PROVE_RCU_LIST is enabled, fprobe triggers the following
warning:
WARNING: suspicious RCU usage
kernel/trace/fprobe.c:457 RCU-list traversed in non-reader section!!
other info that might help us debug this:
#1: ffffffff863c4e08 (fprobe_mutex){+.+.}-{4:4}, at: fprobe_module_callback+0x7b/0x8c0
Call Trace:
fprobe_module_callback
notifier_call_chain
blocking_notifier_call_chain
This warning occurs because fprobe_remove_node_in_module() traverses an
RCU list using RCU primitives without holding an RCU read lock. However,
the function is only called from fprobe_module_callback(), which holds
the fprobe_mutex lock that provides sufficient protection for safely
traversing the list.
Fix the warning by specifying the locking design to the
CONFIG_PROVE_RCU_LIST mechanism. Add the lockdep_is_held() argument to
hlist_for_each_entry_rcu() to inform the RCU checker that fprobe_mutex
provides the required protection.
Link: https://lore.kernel.org/all/20250410-fprobe-v1-1-068ef5f41436@debian.org/
Fixes: a3dc2983ca ("tracing: fprobe: Cleanup fprobe hash when module unloading")
Signed-off-by: Breno Leitao <leitao@debian.org>
Tested-by: Antonio Quartulli <antonio@mandelbit.com>
Tested-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Adding support to retrieve ref_ctr_offset for uprobe perf link,
which got somehow omitted from the initial uprobe link info changes.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yafang Shao <laoar.shao@gmail.com>
Link: https://lore.kernel.org/bpf/20250509153539.779599-2-jolsa@kernel.org
There are applications that have it hard coded to write into the top level
trace_marker instance (/sys/kernel/tracing/trace_marker). This can be
annoying if a profiler is using that instance for other work, or if it
needs all writes to go into a new instance.
A new option is created called "copy_trace_marker". By default, the top
level has this set, as that is the default buffer that writing into the
top level trace_marker file will go to. But now if an instance is created
and sets this option, all writes into the top level trace_marker will also
be written into that instance buffer just as if an application were to
write into the instance's trace_marker file.
If the top level instance disables this option, then writes to its own
trace_marker and trace_marker_raw files will not go into its buffer.
If no instance has this option set, then the write will return an error
and errno will contain ENODEV.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20250508095639.39f84eda@gandalf.local.home
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Add a helper function called handle_dereference_arg() to replace the logic
that is identical in two locations of test_event_printk().
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20250507191703.5dd8a61d@gandalf.local.home
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
There's several functions that have "goto out;" where the label out is just:
out:
return ret;
Simplify the code by just doing the return in the location and removing
all the out labels and jumps.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Tom Zanussi <zanussi@kernel.org>
Link: https://lore.kernel.org/20250507145456.121186494@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
According to trigger_data_alloc() doc, trigger_data_free() should be
used to free an event_trigger_data object. This fixes a mismatch introduced
when kzalloc was replaced with trigger_data_alloc without updating
the corresponding deallocation calls.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Tom Zanussi <zanussi@kernel.org>
Link: https://lore.kernel.org/20250507145455.944453325@goodmis.org
Link: https://lore.kernel.org/20250318112737.4174-1-linmq006@gmail.com
Fixes: e1f187d09e ("tracing: Have existing event_command.parse() implementations use helpers")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
[ SDR: Changed event_trigger_alloc/free() to trigger_data_alloc/free() ]
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The function event_trigger_alloc() creates an event_trigger_data
descriptor and states that it needs to be freed via event_trigger_free().
This is incorrect, it needs to be freed by trigger_data_free() as
event_trigger_free() adds ref counting.
Rename event_trigger_alloc() to trigger_data_alloc() and state that it
needs to be freed via trigger_data_free(). This naming convention
was introducing bugs.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Tom Zanussi <zanussi@kernel.org>
Link: https://lore.kernel.org/20250507145455.776436410@goodmis.org
Fixes: 86599dbe2c ("tracing: Add helper functions to simplify event_command.parse() callback handling")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The trace_array_cpu had a "buffer_page" field that was originally going to
be used as a backup page for the ring buffer. But the ring buffer has its
own way of reusing pages and this field was never used.
Remove it.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://lore.kernel.org/20250505212236.738849456@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The irqsoff tracer uses the per CPU "disabled" field to prevent corruption
of the accounting when it starts to trace interrupts disabled, but there's
a slight race that could happen if for some reason it was called twice.
Use atomic_inc_return() instead.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://lore.kernel.org/20250505212236.567884756@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The per CPU "disabled" counter is used for the latency tracers and stack
tracers to make sure that their accounting isn't messed up by an NMI or
interrupt coming in and affecting the same CPU data. But the counter is an
atomic_t type. As it only needs to synchronize against the current CPU,
switch it over to local_t type.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://lore.kernel.org/20250505212236.394925376@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The branch tracer currently checks the per CPU "disabled" field to know if
tracing is enabled or not for the CPU. As the "disabled" value is not used
anymore to turn of tracing generically, use tracing_tracer_is_on_cpu()
instead.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://lore.kernel.org/20250505212236.224658526@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Add the function ring_buffer_record_is_on_cpu() that returns true if the
ring buffer for a give CPU is writable and false otherwise.
Also add tracer_tracing_is_on_cpu() to return if the ring buffer for a
given CPU is writeable for a given trace_array.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://lore.kernel.org/20250505212236.059853898@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The per CPU "disabled" value was the original way to disable tracing when
the tracing subsystem was first created. Today, the ring buffer
infrastructure has its own way to disable tracing. In fact, things have
changed so much since 2008 that many things ignore the disable flag.
Do not bother setting the per CPU disabled flag of the array_buffer data
to use to determine what CPUs can write to the buffer and only rely on the
ring buffer code itself to disabled it.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://lore.kernel.org/20250505212235.885452497@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The per CPU "disabled" value was the original way to disable tracing when
the tracing subsystem was first created. Today, the ring buffer
infrastructure has its own way to disable tracing. In fact, things have
changed so much since 2008 that many things ignore the disable flag.
Do not bother disabling the function graph tracer if the per CPU disabled
field is set. Just record as normal. If tracing is disabled in the ring
buffer it will not be recorded.
Also, when tracing is enabled again, it will not drop the return call of
the function.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://lore.kernel.org/20250505212235.715752008@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The per CPU "disabled" value was the original way to disable tracing when
the tracing subsystem was first created. Today, the ring buffer
infrastructure has its own way to disable tracing. In fact, things have
changed so much since 2008 that many things ignore the disable flag.
The kdb_ftdump() function iterates over all the current tracing CPUs and
increments the "disabled" counter before doing the dump, and decrements it
afterward.
As the disabled flag can be ignored, doing this today is not reliable.
Instead, simply call tracer_tracing_off() and then tracer_tracing_on() to
disable and then enabled the entire ring buffer in one go!
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Daniel Thompson <danielt@kernel.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/20250505212235.549033722@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The per CPU "disabled" value was the original way to disable tracing when
the tracing subsystem was first created. Today, the ring buffer
infrastructure has its own way to disable tracing. In fact, things have
changed so much since 2008 that many things ignore the disable flag.
The ftrace_dump_one() function iterates over all the current tracing CPUs and
increments the "disabled" counter before doing the dump, and decrements it
afterward.
As the disabled flag can be ignored, doing this today is not reliable.
Instead use the new tracer_tracing_disable() that calls into the ring
buffer code to do the disabling.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://lore.kernel.org/20250505212235.381188238@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Allow a tracer to disable writing to its buffer for a temporary amount of
time and re-enable it.
The tracer_tracing_disable() will disable writing to the trace array
buffer, and requires a tracer_tracing_enable() to re-enable it.
The difference between tracer_tracing_disable() and tracer_tracing_off()
is that the disable version can nest, and requires as many enable() calls
as disable() calls to re-enable the buffer. Where as the off() function
can be called multiple times and only requires a singe tracer_tracing_on()
to re-enable the buffer.
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Daniel Thompson <danielt@kernel.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/20250505212235.210330010@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Marek reported that the rework of handle_nested_irq() introduced a inverted
condition, which prevents handling of interrupts. Fix it up.
Fixes: 2ef2e13094 ("genirq/chip: Rework handle_nested_irq()")
Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Closes: https://lore.kernel/org/all/46ed4040-ca11-4157-8bd7-13c04c113734@samsung.com
task_storage_{get,delete} has been moved to bpf_base_func_proto.
Suggested-by: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Signed-off-by: Feng Yang <yangfeng@kylinos.cn>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/bpf/20250506061434.94277-3-yangfeng59949@163.com
Commit ec5fbdfb99 ("cgroup/cpuset: Enable update_tasks_cpumask()
on top_cpuset") enabled us to pull CPUs dedicated to child partitions
from tasks in top_cpuset by ignoring per cpu kthreads. However, there
can be other kthreads that are not per cpu but have PF_NO_SETAFFINITY
flag set to indicate that we shouldn't mess with their CPU affinity.
For other kthreads, their affinity will be changed to skip CPUs dedicated
to child partitions whether it is an isolating or a scheduling one.
As all the per cpu kthreads have PF_NO_SETAFFINITY set, the
PF_NO_SETAFFINITY tasks are essentially a superset of per cpu kthreads.
Fix this issue by dropping the kthread_is_per_cpu() check and checking
the PF_NO_SETAFFINITY flag instead.
Fixes: ec5fbdfb99 ("cgroup/cpuset: Enable update_tasks_cpumask() on top_cpuset")
Signed-off-by: Waiman Long <longman@redhat.com>
Acked-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
Empty cpumasks can't intersect with any others. Therefore, testing for
non-emptyness is useless.
Signed-off-by: Yury Norov <yury.norov@gmail.com>
Reviewed-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
In preparation for supporting BPF load-acquire and store-release
instructions for architectures where bpf_jit_needs_zext() returns true
(e.g. riscv64), make insn_def_regno() handle load-acquires properly.
Acked-by: Björn Töpel <bjorn@kernel.org>
Tested-by: Björn Töpel <bjorn@rivosinc.com> # QEMU/RVA23
Signed-off-by: Peilin Ye <yepeilin@google.com>
Reviewed-by: Pu Lehui <pulehui@huawei.com>
Link: https://lore.kernel.org/r/09cb2aec979aaed9d16db41f0f5b364de39377c0.1746588351.git.yepeilin@google.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Turn the default 5 second test delay for hibernation into a
configurable module parameter, so users can determine how
long to wait in this pseudo-hibernate state before resuming
the system.
The configurable delay parameter has been added for suspend, so
add an analogous one for hibernation.
Example (wait 30 seconds);
# echo 30 > /sys/module/hibernate/parameters/pm_test_delay
# echo core > /sys/power/pm_test
Signed-off-by: Zihuan Zhang <zhangzihuan@kylinos.cn>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://patch.msgid.link/20250507063520.419635-1-zhangzihuan@kylinos.cn
[ rjw: Subject and changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
pm_show_wakelocks() is called to generate a string when showing
attributes /sys/power/wake_(lock|unlock), but the string ends
with an unwanted space that was added back by mistake by commit
c9d967b2ce ("PM: wakeup: simplify the output logic of
pm_show_wakelocks()").
Remove the unwanted space.
Fixes: c9d967b2ce ("PM: wakeup: simplify the output logic of pm_show_wakelocks()")
Signed-off-by: Zijun Hu <quic_zijuhu@quicinc.com>
Link: https://patch.msgid.link/20250505-fix_power-v1-1-0f7f2c2f338c@quicinc.com
[ rjw: Changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
In free_nsproxy() and the error path of create_new_namesapces() the
put_*_ns() calls are guarded by unnecessary NULL checks.
put_pid_ns(), put_ipc_ns(), put_uts_ns(), and put_time_ns() will never
receive a NULL argument unless their namespace type is disabled, and in
this case all four become no-ops at compile time anyway. put_mnt_ns()
will never receive a null argument at any time.
This unguarded usage is in line with other call sites of put_*_ns().
Signed-off-by: Joel Savitz <jsavitz@redhat.com>
Link: https://lore.kernel.org/20250508184930.183040-2-jsavitz@redhat.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
Now all the pieces are in place to actually allow the power subsystem
to freeze/thaw filesystems during suspend/resume. Filesystems are only
frozen and thawed if the power subsystem does actually own the freeze.
We could bubble up errors and fail suspend/resume if the error isn't
EBUSY (aka it's already frozen) but I don't think that this is worth it.
Filesystem freezing during suspend/resume is best-effort. If the user
has 500 ext4 filesystems mounted and 4 fail to freeze for whatever
reason then we simply skip them.
What we have now is already a big improvement and let's see how we fare
with it before making our lives even harder (and uglier) than we have
to.
We add a new sysctl know /sys/power/freeze_filesystems that will allow
userspace to freeze filesystems during suspend/hibernate. For now it
defaults to off. The thaw logic doesn't require checking whether
freezing is enabled because the power subsystem exclusively owns frozen
filesystems for the duration of suspend/hibernate and is able to skip
filesystems it doesn't need to freeze.
Also it is technically possible that filesystem
filesystem_freeze_enabled is true and power freezes the filesystems but
before freezing all processes another process disables
filesystem_freeze_enabled. If power were to place the filesystems_thaw()
call under filesystems_freeze_enabled it would fail to thaw the
fileystems it frozw. The exclusive holder mechanism makes it possible to
iterate through the list without any concern making sure that no
filesystems are left frozen.
Link: https://lore.kernel.org/r/20250402-work-freeze-v2-3-6719a97b52ac@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
While an event tears down all links to it as an aux, the iteration
happens on the event's group leader instead of the group itself.
If the event is a group leader, it has no effect because the event is
also its own group leader. But otherwise there would be a risk to detach
all the siblings events from the wrong group leader.
It just happens to work because each sibling's aux link is tested
against the right event before proceeding. Also the ctx lock is the same
for the events and their group leader so the iteration is safe.
Yet the iteration is confusing. Clarify the actual intent.
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20250424161128.29176-5-frederic@kernel.org
The CPU hotplug handlers are called twice: at prepare and online stage.
Their role is to:
1) Enable/disable a CPU context. This is irrelevant and even buggy at
the prepare stage because the CPU is still offline. On early
secondary CPU up, creating an event attached to that CPU might
silently fail because the CPU context is observed as online but the
context installation's IPI failure is ignored.
2) Update the scope cpumasks and re-migrate the events accordingly in
the CPU down case. This is irrelevant at the prepare stage.
3) Remove the events attached to the context of the offlining CPU. It
even uses an (unnecessary) IPI for it. This is also irrelevant at the
prepare stage.
Also none of the *_PREPARE and *_STARTING architecture perf related CPU
hotplug callbacks rely on CPUHP_PERF_PREPARE.
CPUHP_AP_PERF_ONLINE is enough and the right place to perform the work.
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20250424161128.29176-4-frederic@kernel.org
The following commit:
da916e96e2 ("perf: Make perf_pmu_unregister() useable")
has introduced two significant event's parent lifecycle changes:
1) An event that has exited now has EVENT_TOMBSTONE as a parent.
This can result in a situation where the delayed wakeup irq_work can
accidentally dereference EVENT_TOMBSTONE on:
CPU 0 CPU 1
----- -----
__schedule()
local_irq_disable()
rq_lock()
<NMI>
perf_event_overflow()
irq_work_queue(&child->pending_irq)
</NMI>
perf_event_task_sched_out()
raw_spin_lock(&ctx->lock)
ctx_sched_out()
ctx->is_active = 0
event_sched_out(child)
raw_spin_unlock(&ctx->lock)
perf_event_release_kernel(parent)
perf_remove_from_context(child)
raw_spin_lock_irq(&ctx->lock)
// Sees !ctx->is_active
// Removes from context inline
__perf_remove_from_context(child)
perf_child_detach(child)
event->parent = EVENT_TOMBSTONE
raw_spin_rq_unlock_irq(rq);
<IRQ>
perf_pending_irq()
perf_event_wakeup(child)
ring_buffer_wakeup(child)
rcu_dereference(child->parent->rb) <--- CRASH
This also concerns the call to kill_fasync() on parent->fasync.
2) The final parent reference count decrement can now happen before the
the final child reference count decrement. ie: the parent can now
be freed before its child. On PREEMPT_RT, this can result in a
situation where the delayed wakeup irq_work can accidentally
dereference a freed parent:
CPU 0 CPU 1 CPU 2
----- ----- ------
perf_pmu_unregister()
pmu_detach_events()
pmu_get_event()
atomic_long_inc_not_zero(&child->refcount)
<NMI>
perf_event_overflow()
irq_work_queue(&child->pending_irq);
</NMI>
<IRQ>
irq_work_run()
wake_irq_workd()
</IRQ>
preempt_schedule_irq()
=========> SWITCH to workd
irq_work_run_list()
perf_pending_irq()
perf_event_wakeup(child)
ring_buffer_wakeup(child)
event = child->parent
perf_event_release_kernel(parent)
// Not last ref, PMU holds it
put_event(child)
// Last ref
put_event(parent)
free_event()
call_rcu(...)
rcu_core()
free_event_rcu()
rcu_dereference(event->rb) <--- CRASH
This also concerns the call to kill_fasync() on parent->fasync.
The "easy" solution to 1) is to check that event->parent is not
EVENT_TOMBSTONE on perf_event_wakeup() (including both ring buffer
and fasync uses).
The "easy" solution to 2) is to turn perf_event_wakeup() to wholefully
run under rcu_read_lock().
However because of 2), sanity would prescribe to make event::parent
an __rcu pointer and annotate each and every users to prove they are
reliable.
Propose an alternate solution and restore the stable pointer to the
parent until all its children have called _free_event() themselves to
avoid any further accident. Also revert the EVENT_TOMBSTONE design
that is mostly here to determine which caller of perf_event_exit_event()
must perform the refcount decrement on a child event matching the
increment in inherit_event().
Arrange instead for checking the attach state of an event prior to its
removal and decrement the refcount of the child accordingly.
Fixes: da916e96e2 ("perf: Make perf_pmu_unregister() useable")
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
When inherit_event() fails after the child allocation but before the
parent refcount has been incremented, calling put_event() wrongly
decrements the reference to the parent, risking to free it too early.
Also pmu_get_event() can't be holding a reference to the child
concurrently at this point since it is under pmus_srcu critical section.
Fix it with restoring the deleted free_event() function and call it on
the failing child in order to free it directly under the verified
assumption that its refcount is only 1. The refcount to the parent is
then voluntarily omitted.
Fixes: da916e96e2 ("perf: Make perf_pmu_unregister() useable")
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20250424161128.29176-2-frederic@kernel.org
The ignore_pid boolean on the per CPU data descriptor is updated at
sched_switch when a new task is scheduled in. If the new task is to be
ignored, it is set to true, otherwise it is set to false. The current task
should always have the correct value as it is updated when the task is
scheduled in.
Instead of breaking up the read of this value, which requires preemption
to be disabled, just use this_cpu_read() which gives a snapshot of the
value. Since the value will always be correct for a given task (because
it's updated at sched switch) it doesn't need preemption disabled.
This will also allow trace events to be called with preemption enabled.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://lore.kernel.org/20250505212235.038958766@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The per CPU "disabled" value was the original way to disable tracing when
the tracing subsystem was first created. Today, the ring buffer
infrastructure has its own way to disable tracing. In fact, things have
changed so much since 2008 that many things ignore the disable flag.
There's no reason for the function tracer to check it, if tracing is
disabled, the ring buffer will not record the event anyway.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://lore.kernel.org/20250505212234.868972758@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The mmiotracer referenced the per CPU array_buffer->data descriptor but
never actually used it. Remove the references to it.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://lore.kernel.org/20250505212234.696945463@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Allocate kernel memory for processing CPU string
(/sys/kernel/tracing/osnoise/cpus) also in osnoise_cpus_write to allow
the writing of a CPU string of an arbitrary length.
This replaces the 256-byte buffer, which is insufficient with the rising
number of CPUs. For example, if I wanted to measure on every even CPU
on a system with 256 CPUs, the string would be 456 characters long.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20250425091839.343289-1-tglozar@redhat.com
Signed-off-by: Tomas Glozar <tglozar@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The structure ftrace_func_mapper only contains a single field and that is
a ftrace_hash. It is used to abstract it out from a normal hash to control
users of how it gets modified.
The freeing of a ftrace_func_mapper structure is:
free_ftrace_hash(&mapper->hash);
Without context, this looks like a bug. It should be commented that it is
not a bug and it is freed this way.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/20250416165420.5c717420@gandalf.local.home
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Depth is stored as int because the code uses negative values to break
out of iterations. But what is recorded is always zero or positive. So
expose it as unsigned int instead of int.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Link: https://lore.kernel.org/20250412221847.17310-3-iii@linux.ibm.com
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The function graph infrastructure uses subops of the function tracer.
These are not shown in enabled_functions. Add a "subops:" section to the
enabled_functions line to show what functions are attached via subops. If
the subops is from the function_graph infrastructure, then show the entry
and return callbacks that are attached.
Here's an example of the output:
schedule_on_each_cpu (1) tramp: 0xffffffffc03ef000 (ftrace_graph_func+0x0/0x60) ->ftrace_graph_func+0x0/0x60 subops: {ent:trace_graph_entry+0x0/0x20 ret:trace_graph_return+0x0/0x150}
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20250410153830.5d97f108@gandalf.local.home
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The lock guard conversion converted raw_spin_lock_irq() to
scoped_guard(raw_spinlock), which is obviously bogus and makes lockdep
mightily unhappy.
Note to self: Copy and pasta without using brain is a patently bad idea.
Fixes: 88a4df117a ("genirq/cpuhotplug: Convert to lock guards")
Reported-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Borislav Petkov <bp@alien8.de>
Doing cpufreq-specific EAS checks that require accessing policy
internals directly from sched_is_eas_possible() is a bit unfortunate,
so introduce cpufreq_ready_for_eas() in cpufreq, move those checks
into that new function and make sched_is_eas_possible() call it.
While at it, address a possible race between the EAS governor check
and governor change by doing the former under the policy rwsem.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Christian Loehle <christian.loehle@arm.com>
Tested-by: Christian Loehle <christian.loehle@arm.com>
Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Link: https://patch.msgid.link/2317800.iZASKD2KPV@rjwysocki.net
Add a helper for checking if schedutil is the current governor for
a given cpufreq policy and use it in sched_is_eas_possible() to avoid
accessing cpufreq policy internals directly from there.
No intentional functional impact.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Christian Loehle <christian.loehle@arm.com>
Tested-by: Christian Loehle <christian.loehle@arm.com>
Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Link: https://patch.msgid.link/3365956.44csPzL39Z@rjwysocki.net
In 'lookup_or_create_module_kobject()', an internal kobject is created
using 'module_ktype'. So call to 'kobject_put()' on error handling
path causes an attempt to use an uninitialized completion pointer in
'module_kobject_release()'. In this scenario, we just want to release
kobject without an extra synchronization required for a regular module
unloading process, so adding an extra check whether 'complete()' is
actually required makes 'kobject_put()' safe.
Reported-by: syzbot+7fb8a372e1f6add936dd@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=7fb8a372e1f6add936dd
Fixes: 942e443127 ("module: Fix mod->mkobj.kobj potentially freed too early")
Cc: stable@vger.kernel.org
Suggested-by: Petr Pavlu <petr.pavlu@suse.com>
Signed-off-by: Dmitry Antipov <dmantipov@yandex.ru>
Link: https://lore.kernel.org/r/20250507065044.86529-1-dmantipov@yandex.ru
Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
To receive 428dc9fc08 ("sched_ext: bpf_iter_scx_dsq_new() should always
initialize iterator") which conflicts with cdf5a6faa8 ("sched_ext: Move
dsq_hash into scx_sched"). The conflict is a simple context conflict which
can be resolved by taking changes from both changes in the right order.
BPF programs may call next() and destroy() on BPF iterators even after new()
returns an error value (e.g. bpf_for_each() macro ignores error returns from
new()). bpf_iter_scx_dsq_new() could leave the iterator in an uninitialized
state after an error return causing bpf_iter_scx_dsq_next() to dereference
garbage data. Make bpf_iter_scx_dsq_new() always clear $kit->dsq so that
next() and destroy() become noops.
Signed-off-by: Tejun Heo <tj@kernel.org>
Fixes: 650ba21b13 ("sched_ext: Implement DSQ iterator")
Cc: stable@vger.kernel.org # v6.12+
Acked-by: Andrea Righi <arighi@nvidia.com>
This code pattern trips clang up:
if (fail)
goto undo;
guard(lock)(lock);
do_stuff();
return 0;
undo:
...
as it somehow extends the scope of the guard beyond the return statement.
Replace it with a scoped guard to help it to get its act together.
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Closes: https://lore.kernel.org/oe-kbuild-all/202505071809.ajpPxfoZ-lkp@intel.com/
Split hib_submit_io into a sync and async version. The sync version is
a small wrapper around bdev_rw_virt which implements all the logic to
add a kernel direct mapping range to a bio and synchronously submits it,
while the async version is slightly simplified using the
bio_add_virt_nofail for adding the single range.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20250507120451.4000627-13-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
