dma_supported has become too much spaghetti for my taste. Reflow it to
remove the duplicate use_dma_iommu condition and make the main path more
obvious.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Leon Romanovsky <leon@kernel.org>
When debugging drivers, it can often be useful to trace when memory gets
(un)mapped for DMA (and can be accessed by the device). Add some
tracepoints for this purpose.
Use u64 instead of phys_addr_t and dma_addr_t (and similarly %llx instead
of %pa) because libtraceevent can't handle typedefs in all cases.
Signed-off-by: Sean Anderson <sean.anderson@linux.dev>
Signed-off-by: Christoph Hellwig <hch@lst.de>
When the CMA allocation succeeds but isn't addressable, its buffer has
already been released and the page is set to NULL. So later when the
normal page allocation succeeds but isn't addressable, __free_pages()
can be used to free that normal page rather than using
dma_free_contiguous that does extra checks that are not needed.
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
DMA ops are a helper for architectures and not for drivers to override
the DMA implementation.
Unfortunately driver authors keep ignoring this. Make the fact more
clear by renaming the symbol to ARCH_HAS_DMA_OPS and having the two drivers
overriding their dma_ops depend on that. These drivers should probably be
marked broken, but we can give them a bit of a grace period for that.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com> # for IPU6
Acked-by: Robin Murphy <robin.murphy@arm.com>
Directly call into dma-iommu just like we have been doing for dma-direct
for a while. This avoids the indirect call overhead for IOMMU ops and
removes the need to have DMA ops entirely for many common configurations.
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Almost all instances of the dma_map_ops ->map_page()/map_sg() methods
implement ->unmap_page()/unmap_sg() too. The once instance which doesn't
dma_dummy_ops which is used to fail the DMA mapping and thus there won't
be any calls to ->unmap_page()/unmap_sg().
Remove the checks for ->unmap_page()/unmap_sg() and call them directly to
create an interface that is symmetrical to ->map_page()/map_sg().
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
The hardware DMA limit might not be power of 2. When RAM range starts
above 0, say 4GB, DMA limit of 30 bits should end at 5GB. A single high
bit can not encode this limit.
Use a plain address for the DMA zone limit instead.
Since the DMA zone can now potentially span beyond 4GB physical limit of
DMA32, make sure to use DMA zone for GFP_DMA32 allocations in that case.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Co-developed-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Petr Tesarik <ptesarik@suse.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
In dma_common_find_pages(), area->flags are compared directly with
VM_DMA_COHERENT. This works because VM_DMA_COHERENT is the only set
flag.
During development of a new feature (ASI [1]), a new VM flag is
introduced, and that flag can be injected into VM_DMA_COHERENT mappings
(among others). The presence of that flag caused
dma_common_find_pages() to return NULL for VM_DMA_COHERENT addresses,
leading to a lot of problems ending in crashing during boot. It took a
bit of time to figure this problem out.
It was a mistake to inject a VM flag to begin with, but it took a
significant amount of debugging to figure out the problem. Most users of
area->flags use bitmasking rather than equivalency to check for flags.
Update dma_common_find_pages() and dma_common_free_remap() to do the
same, which would have avoided the boot crashing. Instead, add a warning
in dma_common_find_pages() if any extra VM flags are set to catch such
problems more easily during development.
No functional change intended.
[1]https://lore.kernel.org/lkml/20240712-asi-rfc-24-v1-0-144b319a40d8@google.com/
Signed-off-by: Yosry Ahmed <yosryahmed@google.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Pull misc fixes from Andrew Morton:
"16 hotfixes. All except one are for MM. 10 of these are cc:stable and
the others pertain to post-6.10 issues.
As usual with these merges, singletons and doubletons all over the
place, no identifiable-by-me theme. Please see the lovingly curated
changelogs to get the skinny"
* tag 'mm-hotfixes-stable-2024-08-17-19-34' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
mm/migrate: fix deadlock in migrate_pages_batch() on large folios
alloc_tag: mark pages reserved during CMA activation as not tagged
alloc_tag: introduce clear_page_tag_ref() helper function
crash: fix riscv64 crash memory reserve dead loop
selftests: memfd_secret: don't build memfd_secret test on unsupported arches
mm: fix endless reclaim on machines with unaccepted memory
selftests/mm: compaction_test: fix off by one in check_compaction()
mm/numa: no task_numa_fault() call if PMD is changed
mm/numa: no task_numa_fault() call if PTE is changed
mm/vmalloc: fix page mapping if vm_area_alloc_pages() with high order fallback to order 0
mm/memory-failure: use raw_spinlock_t in struct memory_failure_cpu
mm: don't account memmap per-node
mm: add system wide stats items category
mm: don't account memmap on failure
mm/hugetlb: fix hugetlb vs. core-mm PT locking
mseal: fix is_madv_discard()
Pull powerpc fixes from Michael Ellerman:
- Fix crashes on 85xx with some configs since the recent hugepd rework.
- Fix boot warning with hugepages and CONFIG_DEBUG_VIRTUAL on some
platforms.
- Don't enable offline cores when changing SMT modes, to match existing
userspace behaviour.
Thanks to Christophe Leroy, Dr. David Alan Gilbert, Guenter Roeck, Nysal
Jan K.A, Shrikanth Hegde, Thomas Gleixner, and Tyrel Datwyler.
* tag 'powerpc-6.11-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
powerpc/topology: Check if a core is online
cpu/SMT: Enable SMT only if a core is online
powerpc/mm: Fix boot warning with hugepages and CONFIG_DEBUG_VIRTUAL
powerpc/mm: Fix size of allocated PGDIR
soc: fsl: qbman: remove unused struct 'cgr_comp'
Pull tracing fixes from Steven Rostedt:
"A couple of fixes for tracing:
- Prevent a NULL pointer dereference in the error path of RTLA tool
- Fix an infinite loop bug when reading from the ring buffer when
closed. If there's a thread trying to read the ring buffer and it
gets closed by another thread, the one reading will go into an
infinite loop when the buffer is empty instead of exiting back to
user space"
* tag 'trace-v6.11-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
rtla/osnoise: Prevent NULL dereference in error handling
tracing: Return from tracing_buffers_read() if the file has been closed
On RISCV64 Qemu machine with 512MB memory, cmdline "crashkernel=500M,high"
will cause system stall as below:
Zone ranges:
DMA32 [mem 0x0000000080000000-0x000000009fffffff]
Normal empty
Movable zone start for each node
Early memory node ranges
node 0: [mem 0x0000000080000000-0x000000008005ffff]
node 0: [mem 0x0000000080060000-0x000000009fffffff]
Initmem setup node 0 [mem 0x0000000080000000-0x000000009fffffff]
(stall here)
commit 5d99cadf1568 ("crash: fix x86_32 crash memory reserve dead loop
bug") fix this on 32-bit architecture. However, the problem is not
completely solved. If `CRASH_ADDR_LOW_MAX = CRASH_ADDR_HIGH_MAX` on
64-bit architecture, for example, when system memory is equal to
CRASH_ADDR_LOW_MAX on RISCV64, the following infinite loop will also
occur:
-> reserve_crashkernel_generic() and high is true
-> alloc at [CRASH_ADDR_LOW_MAX, CRASH_ADDR_HIGH_MAX] fail
-> alloc at [0, CRASH_ADDR_LOW_MAX] fail and repeatedly
(because CRASH_ADDR_LOW_MAX = CRASH_ADDR_HIGH_MAX).
As Catalin suggested, do not remove the ",high" reservation fallback to
",low" logic which will change arm64's kdump behavior, but fix it by
skipping the above situation similar to commit d2f32f23190b ("crash: fix
x86_32 crash memory reserve dead loop").
After this patch, it print:
cannot allocate crashkernel (size:0x1f400000)
Link: https://lkml.kernel.org/r/20240812062017.2674441-1-ruanjinjie@huawei.com
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Suggested-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Baoquan He <bhe@redhat.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Dave Young <dyoung@redhat.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Pull hardening fixes from Kees Cook:
- gcc-plugins: randstruct: Remove GCC 4.7 or newer requirement
(Thorsten Blum)
- kallsyms: Clean up interaction with LTO suffixes (Song Liu)
- refcount: Report UAF for refcount_sub_and_test(0) when counter==0
(Petr Pavlu)
- kunit/overflow: Avoid misallocation of driver name (Ivan Orlov)
* tag 'hardening-v6.11-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
kallsyms: Match symbols exactly with CONFIG_LTO_CLANG
kallsyms: Do not cleanup .llvm.<hash> suffix before sorting symbols
kunit/overflow: Fix UB in overflow_allocation_test
gcc-plugins: randstruct: Remove GCC 4.7 or newer requirement
refcount: Report UAF for refcount_sub_and_test(0) when counter==0
With CONFIG_LTO_CLANG=y, the compiler may add .llvm.<hash> suffix to
function names to avoid duplication. APIs like kallsyms_lookup_name()
and kallsyms_on_each_match_symbol() tries to match these symbol names
without the .llvm.<hash> suffix, e.g., match "c_stop" with symbol
c_stop.llvm.17132674095431275852. This turned out to be problematic
for use cases that require exact match, for example, livepatch.
Fix this by making the APIs to match symbols exactly.
Also cleanup kallsyms_selftests accordingly.
Signed-off-by: Song Liu <song@kernel.org>
Fixes: 8cc32a9bbf ("kallsyms: strip LTO-only suffixes from promoted global functions")
Tested-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Petr Mladek <pmladek@suse.com>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Link: https://lore.kernel.org/r/20240807220513.3100483-3-song@kernel.org
Signed-off-by: Kees Cook <kees@kernel.org>
Pull vfs fixes from Christian Brauner:
"VFS:
- Fix the name of file lease slab cache. When file leases were split
out of file locks the name of the file lock slab cache was used for
the file leases slab cache as well.
- Fix a type in take_fd() helper.
- Fix infinite directory iteration for stable offsets in tmpfs.
- When the icache is pruned all reclaimable inodes are marked with
I_FREEING and other processes that try to lookup such inodes will
block.
But some filesystems like ext4 can trigger lookups in their inode
evict callback causing deadlocks. Ext4 does such lookups if the
ea_inode feature is used whereby a separate inode may be used to
store xattrs.
Introduce I_LRU_ISOLATING which pins the inode while its pages are
reclaimed. This avoids inode deletion during inode_lru_isolate()
avoiding the deadlock and evict is made to wait until
I_LRU_ISOLATING is done.
netfs:
- Fault in smaller chunks for non-large folio mappings for
filesystems that haven't been converted to large folios yet.
- Fix the CONFIG_NETFS_DEBUG config option. The config option was
renamed a short while ago and that introduced two minor issues.
First, it depended on CONFIG_NETFS whereas it wants to depend on
CONFIG_NETFS_SUPPORT. The former doesn't exist, while the latter
does. Second, the documentation for the config option wasn't fixed
up.
- Revert the removal of the PG_private_2 writeback flag as ceph is
using it and fix how that flag is handled in netfs.
- Fix DIO reads on 9p. A program watching a file on a 9p mount
wouldn't see any changes in the size of the file being exported by
the server if the file was changed directly in the source
filesystem. Fix this by attempting to read the full size specified
when a DIO read is requested.
- Fix a NULL pointer dereference bug due to a data race where a
cachefiles cookies was retired even though it was still in use.
Check the cookie's n_accesses counter before discarding it.
nsfs:
- Fix ioctl declaration for NS_GET_MNTNS_ID from _IO() to _IOR() as
the kernel is writing to userspace.
pidfs:
- Prevent the creation of pidfds for kthreads until we have a
use-case for it and we know the semantics we want. It also confuses
userspace why they can get pidfds for kthreads.
squashfs:
- Fix an unitialized value bug reported by KMSAN caused by a
corrupted symbolic link size read from disk. Check that the
symbolic link size is not larger than expected"
* tag 'vfs-6.11-rc4.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
Squashfs: sanity check symbolic link size
9p: Fix DIO read through netfs
vfs: Don't evict inode under the inode lru traversing context
netfs: Fix handling of USE_PGPRIV2 and WRITE_TO_CACHE flags
netfs, ceph: Revert "netfs: Remove deprecated use of PG_private_2 as a second writeback flag"
file: fix typo in take_fd() comment
pidfd: prevent creation of pidfds for kthreads
netfs: clean up after renaming FSCACHE_DEBUG config
libfs: fix infinite directory reads for offset dir
nsfs: fix ioctl declaration
fs/netfs/fscache_cookie: add missing "n_accesses" check
filelock: fix name of file_lease slab cache
netfs: Fault in smaller chunks for non-large folio mappings
The regressing commit is new in 6.10. It assumed that anytime event->prog
is set bpf_overflow_handler() should be invoked to execute the attached bpf
program. This assumption is false for tracing events, and as a result the
regressing commit broke bpftrace by invoking the bpf handler with garbage
inputs on overflow.
Prior to the regression the overflow handlers formed a chain (of length 0,
1, or 2) and perf_event_set_bpf_handler() (the !tracing case) added
bpf_overflow_handler() to that chain, while perf_event_attach_bpf_prog()
(the tracing case) did not. Both set event->prog. The chain of overflow
handlers was replaced by a single overflow handler slot and a fixed call to
bpf_overflow_handler() when appropriate. This modifies the condition there
to check event->prog->type == BPF_PROG_TYPE_PERF_EVENT, restoring the
previous behavior and fixing bpftrace.
Signed-off-by: Kyle Huey <khuey@kylehuey.com>
Suggested-by: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Reported-by: Joe Damato <jdamato@fastly.com>
Closes: https://lore.kernel.org/lkml/ZpFfocvyF3KHaSzF@LQ3V64L9R2/
Fixes: f11f10bfa1 ("perf/bpf: Call BPF handler directly, not through overflow machinery")
Cc: stable@vger.kernel.org
Tested-by: Joe Damato <jdamato@fastly.com> # bpftrace
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20240813151727.28797-1-jdamato@fastly.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Daniel Hodges reported a kernel verifier crash when playing with sched-ext.
Further investigation shows that the crash is due to invalid memory access
in stacksafe(). More specifically, it is the following code:
if (exact != NOT_EXACT &&
old->stack[spi].slot_type[i % BPF_REG_SIZE] !=
cur->stack[spi].slot_type[i % BPF_REG_SIZE])
return false;
The 'i' iterates old->allocated_stack.
If cur->allocated_stack < old->allocated_stack the out-of-bound
access will happen.
To fix the issue add 'i >= cur->allocated_stack' check such that if
the condition is true, stacksafe() should fail. Otherwise,
cur->stack[spi].slot_type[i % BPF_REG_SIZE] memory access is legal.
Fixes: 2793a8b015 ("bpf: exact states comparison for iterator convergence checks")
Cc: Eduard Zingerman <eddyz87@gmail.com>
Reported-by: Daniel Hodges <hodgesd@meta.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20240812214847.213612-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
If a core is offline then enabling SMT should not online CPUs of
this core. By enabling SMT, what is intended is either changing the SMT
value from "off" to "on" or setting the SMT level (threads per core) from a
lower to higher value.
On PowerPC the ppc64_cpu utility can be used, among other things, to
perform the following functions:
ppc64_cpu --cores-on # Get the number of online cores
ppc64_cpu --cores-on=X # Put exactly X cores online
ppc64_cpu --offline-cores=X[,Y,...] # Put specified cores offline
ppc64_cpu --smt={on|off|value} # Enable, disable or change SMT level
If the user has decided to offline certain cores, enabling SMT should
not online CPUs in those cores. This patch fixes the issue and changes
the behaviour as described, by introducing an arch specific function
topology_is_core_online(). It is currently implemented only for PowerPC.
Fixes: 73c58e7e14 ("powerpc: Add HOTPLUG_SMT support")
Reported-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Closes: https://groups.google.com/g/powerpc-utils-devel/c/wrwVzAAnRlI/m/5KJSoqP4BAAJ
Signed-off-by: Nysal Jan K.A <nysal@linux.ibm.com>
Reviewed-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240731030126.956210-2-nysal@linux.ibm.com
Pull time keeping fixes from Thomas Gleixner:
- Fix a couple of issues in the NTP code where user supplied values are
neither sanity checked nor clamped to the operating range. This
results in integer overflows and eventualy NTP getting out of sync.
According to the history the sanity checks had been removed in favor
of clamping the values, but the clamping never worked correctly under
all circumstances. The NTP people asked to not bring the sanity
checks back as it might break existing applications.
Make the clamping work correctly and add it where it's missing
- If adjtimex() sets the clock it has to trigger the hrtimer subsystem
so it can adjust and if the clock was set into the future expire
timers if needed. The caller should provide a bitmask to tell
hrtimers which clocks have been adjusted.
adjtimex() uses not the proper constant and uses CLOCK_REALTIME
instead, which is 0. So hrtimers adjusts only the clocks, but does
not check for expired timers, which might make them expire really
late. Use the proper bitmask constant instead.
* tag 'timers-urgent-2024-08-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
timekeeping: Fix bogus clock_was_set() invocation in do_adjtimex()
ntp: Safeguard against time_constant overflow
ntp: Clamp maxerror and esterror to operating range
Pull irq fixes from Thomas Gleixner:
"Three small fixes for interrupt core and drivers:
- The interrupt core fails to honor caller supplied affinity hints
for non-managed interrupts and uses the system default affinity on
startup instead. Set the missing flag in the descriptor to tell the
core to use the provided affinity.
- Fix a shift out of bounds error in the Xilinx driver
- Handle switching to level trigger correctly in the RISCV APLIC
driver. It failed to retrigger the interrupt which causes it to
become stale"
* tag 'irq-urgent-2024-08-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
irqchip/riscv-aplic: Retrigger MSI interrupt on source configuration
irqchip/xilinx: Fix shift out of bounds
genirq/irqdesc: Honor caller provided affinity in alloc_desc()
Pull dma-mapping fix from Christoph Hellwig:
- avoid a deadlock with dma-debug and netconsole (Rik van Riel)
* tag 'dma-mapping-6.11-2024-08-10' of git://git.infradead.org/users/hch/dma-mapping:
dma-debug: avoid deadlock between dma debug vs printk and netconsole
When running the following:
# cd /sys/kernel/tracing/
# echo 1 > events/sched/sched_waking/enable
# echo 1 > events/sched/sched_switch/enable
# echo 0 > tracing_on
# dd if=per_cpu/cpu0/trace_pipe_raw of=/tmp/raw0.dat
The dd task would get stuck in an infinite loop in the kernel. What would
happen is the following:
When ring_buffer_read_page() returns -1 (no data) then a check is made to
see if the buffer is empty (as happens when the page is not full), it will
call wait_on_pipe() to wait until the ring buffer has data. When it is it
will try again to read data (unless O_NONBLOCK is set).
The issue happens when there's a reader and the file descriptor is closed.
The wait_on_pipe() will return when that is the case. But this loop will
continue to try again and wait_on_pipe() will again return immediately and
the loop will continue and never stop.
Simply check if the file was closed before looping and exit out if it is.
Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20240808235730.78bf63e5@rorschach.local.home
Fixes: 2aa043a55b ("tracing/ring-buffer: Fix wait_on_pipe() race")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Pull kprobe fixes from Masami Hiramatsu:
- Fix misusing str_has_prefix() parameter order to check symbol prefix
correctly
- bpf: remove unused declaring of bpf_kprobe_override
* tag 'probes-fixes-v6.11-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
kprobes: Fix to check symbol prefixes correctly
bpf: kprobe: remove unused declaring of bpf_kprobe_override
The recursive aes-arm-bs module load situation reported by Russell King
is getting fixed in the crypto layer, but this in the meantime fixes the
"recursive load hangs forever" by just making the waiting for the first
module load be interruptible.
This should now match the old behavior before commit 9b9879fc03
("modules: catch concurrent module loads, treat them as idempotent"),
which used the different "wait for module to be ready" code in
module_patient_check_exists().
End result: a recursive module load will still block, but now a signal
will interrupt it and fail the second module load, at which point the
first module will successfully complete loading.
Fixes: 9b9879fc03 ("modules: catch concurrent module loads, treat them as idempotent")
Cc: Russell King <linux@armlinux.org.uk>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull tracing fixes from Steven Rostedt:
- Have reading of event format files test if the metadata still exists.
When a event is freed, a flag (EVENT_FILE_FL_FREED) in the metadata
is set to state that it is to prevent any new references to it from
happening while waiting for existing references to close. When the
last reference closes, the metadata is freed. But the "format" was
missing a check to this flag (along with some other files) that
allowed new references to happen, and a use-after-free bug to occur.
- Have the trace event meta data use the refcount infrastructure
instead of relying on its own atomic counters.
- Have tracefs inodes use alloc_inode_sb() for allocation instead of
using kmem_cache_alloc() directly.
- Have eventfs_create_dir() return an ERR_PTR instead of NULL as the
callers expect a real object or an ERR_PTR.
- Have release_ei() use call_srcu() and not call_rcu() as all the
protection is on SRCU and not RCU.
- Fix ftrace_graph_ret_addr() to use the task passed in and not
current.
- Fix overflow bug in get_free_elt() where the counter can overflow the
integer and cause an infinite loop.
- Remove unused function ring_buffer_nr_pages()
- Have tracefs freeing use the inode RCU infrastructure instead of
creating its own.
When the kernel had randomize structure fields enabled, the rcu field
of the tracefs_inode was overlapping the rcu field of the inode
structure, and corrupting it. Instead, use the destroy_inode()
callback to do the initial cleanup of the code, and then have
free_inode() free it.
* tag 'trace-v6.11-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
tracefs: Use generic inode RCU for synchronizing freeing
ring-buffer: Remove unused function ring_buffer_nr_pages()
tracing: Fix overflow in get_free_elt()
function_graph: Fix the ret_stack used by ftrace_graph_ret_addr()
eventfs: Use SRCU for freeing eventfs_inodes
eventfs: Don't return NULL in eventfs_create_dir()
tracefs: Fix inode allocation
tracing: Use refcount for trace_event_file reference counter
tracing: Have format file honor EVENT_FILE_FL_FREED
Pull bcachefs fixes from Kent Overstreet:
"Assorted little stuff:
- lockdep fixup for lockdep_set_notrack_class()
- we can now remove a device when using erasure coding without
deadlocking, though we still hit other issues
- the 'allocator stuck' timeout is now configurable, and messages are
ratelimited. The default timeout has been increased from 10 seconds
to 30"
* tag 'bcachefs-2024-08-08' of git://evilpiepirate.org/bcachefs:
bcachefs: Use bch2_wait_on_allocator() in btree node alloc path
bcachefs: Make allocator stuck timeout configurable, ratelimit messages
bcachefs: Add missing path_traverse() to btree_iter_next_node()
bcachefs: ec should not allocate from ro devs
bcachefs: Improved allocator debugging for ec
bcachefs: Add missing bch2_trans_begin() call
bcachefs: Add a comment for bucket helper types
bcachefs: Don't rely on implicit unsigned -> signed integer conversion
lockdep: Fix lockdep_set_notrack_class() for CONFIG_LOCK_STAT
bcachefs: Fix double free of ca->buckets_nouse
Russell King reported that the arm cbc(aes) crypto module hangs when
loaded, and Herbert Xu bisected it to commit 9b9879fc03 ("modules:
catch concurrent module loads, treat them as idempotent"), and noted:
"So what's happening here is that the first modprobe tries to load a
fallback CBC implementation, in doing so it triggers a load of the
exact same module due to module aliases.
IOW we're loading aes-arm-bs which provides cbc(aes). However, this
needs a fallback of cbc(aes) to operate, which is made out of the
generic cbc module + any implementation of aes, or ecb(aes). The
latter happens to also be provided by aes-arm-cb so that's why it
tries to load the same module again"
So loading the aes-arm-bs module ends up wanting to recursively load
itself, and the recursive load then ends up waiting for the original
module load to complete.
This is a regression, in that it used to be that we just tried to load
the module multiple times, and then as we went on to install it the
second time we would instead just error out because the module name
already existed.
That is actually also exactly what the original "catch concurrent loads"
patch did in commit 9828ed3f69 ("module: error out early on concurrent
load of the same module file"), but it turns out that it ends up being
racy, in that erroring out before the module has been fully initialized
will cause failures in dependent module loading.
See commit ac2263b588 (which was the revert of that "error out early")
commit for details about why erroring out before the module has been
initialized is actually fundamentally racy.
Now, for the actual recursive module load (as opposed to just
concurrently loading the same module twice), the race is not an issue.
At the same time it's hard for the kernel to see that this is recursion,
because the module load is always done from a usermode helper, so the
recursion is not some simple callchain within the kernel.
End result: this is not the real fix, but this at least adds a warning
for the situation (admittedly much too late for all the debugging pain
that Russell and Herbert went through) and if we can come to a
resolution on how to detect the recursion properly, this re-organizes
the code to make that easier.
Link: https://lore.kernel.org/all/ZrFHLqvFqhzykuYw@shell.armlinux.org.uk/
Reported-by: Russell King <linux@armlinux.org.uk>
Debugged-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull misc fixes from Andrew Morton:
"Nine hotfixes. Five are cc:stable, the others either pertain to
post-6.10 material or aren't considered necessary for earlier kernels.
Five are MM and four are non-MM. No identifiable theme here - please
see the individual changelogs"
* tag 'mm-hotfixes-stable-2024-08-07-18-32' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
padata: Fix possible divide-by-0 panic in padata_mt_helper()
mailmap: update entry for David Heidelberg
memcg: protect concurrent access to mem_cgroup_idr
mm: shmem: fix incorrect aligned index when checking conflicts
mm: shmem: avoid allocating huge pages larger than MAX_PAGECACHE_ORDER for shmem
mm: list_lru: fix UAF for memory cgroup
kcov: properly check for softirq context
MAINTAINERS: Update LTP members and web
selftests: mm: add s390 to ARCH check
We are hit with a not easily reproducible divide-by-0 panic in padata.c at
bootup time.
[ 10.017908] Oops: divide error: 0000 1 PREEMPT SMP NOPTI
[ 10.017908] CPU: 26 PID: 2627 Comm: kworker/u1666:1 Not tainted 6.10.0-15.el10.x86_64 #1
[ 10.017908] Hardware name: Lenovo ThinkSystem SR950 [7X12CTO1WW]/[7X12CTO1WW], BIOS [PSE140J-2.30] 07/20/2021
[ 10.017908] Workqueue: events_unbound padata_mt_helper
[ 10.017908] RIP: 0010:padata_mt_helper+0x39/0xb0
:
[ 10.017963] Call Trace:
[ 10.017968] <TASK>
[ 10.018004] ? padata_mt_helper+0x39/0xb0
[ 10.018084] process_one_work+0x174/0x330
[ 10.018093] worker_thread+0x266/0x3a0
[ 10.018111] kthread+0xcf/0x100
[ 10.018124] ret_from_fork+0x31/0x50
[ 10.018138] ret_from_fork_asm+0x1a/0x30
[ 10.018147] </TASK>
Looking at the padata_mt_helper() function, the only way a divide-by-0
panic can happen is when ps->chunk_size is 0. The way that chunk_size is
initialized in padata_do_multithreaded(), chunk_size can be 0 when the
min_chunk in the passed-in padata_mt_job structure is 0.
Fix this divide-by-0 panic by making sure that chunk_size will be at least
1 no matter what the input parameters are.
Link: https://lkml.kernel.org/r/20240806174647.1050398-1-longman@redhat.com
Fixes: 004ed42638 ("padata: add basic support for multithreaded jobs")
Signed-off-by: Waiman Long <longman@redhat.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: Waiman Long <longman@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
When collecting coverage from softirqs, KCOV uses in_serving_softirq() to
check whether the code is running in the softirq context. Unfortunately,
in_serving_softirq() is > 0 even when the code is running in the hardirq
or NMI context for hardirqs and NMIs that happened during a softirq.
As a result, if a softirq handler contains a remote coverage collection
section and a hardirq with another remote coverage collection section
happens during handling the softirq, KCOV incorrectly detects a nested
softirq coverate collection section and prints a WARNING, as reported by
syzbot.
This issue was exposed by commit a7f3813e58 ("usb: gadget: dummy_hcd:
Switch to hrtimer transfer scheduler"), which switched dummy_hcd to using
hrtimer and made the timer's callback be executed in the hardirq context.
Change the related checks in KCOV to account for this behavior of
in_serving_softirq() and make KCOV ignore remote coverage collection
sections in the hardirq and NMI contexts.
This prevents the WARNING printed by syzbot but does not fix the inability
of KCOV to collect coverage from the __usb_hcd_giveback_urb when dummy_hcd
is in use (caused by a7f3813e58); a separate patch is required for that.
Link: https://lkml.kernel.org/r/20240729022158.92059-1-andrey.konovalov@linux.dev
Fixes: 5ff3b30ab5 ("kcov: collect coverage from interrupts")
Signed-off-by: Andrey Konovalov <andreyknvl@gmail.com>
Reported-by: syzbot+2388cdaeb6b10f0c13ac@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=2388cdaeb6b10f0c13ac
Acked-by: Marco Elver <elver@google.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Aleksandr Nogikh <nogikh@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Marcello Sylvester Bauer <sylv@sylv.io>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
"tracing_map->next_elt" in get_free_elt() is at risk of overflowing.
Once it overflows, new elements can still be inserted into the tracing_map
even though the maximum number of elements (`max_elts`) has been reached.
Continuing to insert elements after the overflow could result in the
tracing_map containing "tracing_map->max_size" elements, leaving no empty
entries.
If any attempt is made to insert an element into a full tracing_map using
`__tracing_map_insert()`, it will cause an infinite loop with preemption
disabled, leading to a CPU hang problem.
Fix this by preventing any further increments to "tracing_map->next_elt"
once it reaches "tracing_map->max_elt".
Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Fixes: 08d43a5fa0 ("tracing: Add lock-free tracing_map")
Co-developed-by: Cheng-Jui Wang <cheng-jui.wang@mediatek.com>
Link: https://lore.kernel.org/20240805055922.6277-1-Tze-nan.Wu@mediatek.com
Signed-off-by: Cheng-Jui Wang <cheng-jui.wang@mediatek.com>
Signed-off-by: Tze-nan Wu <Tze-nan.Wu@mediatek.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
When eventfs was introduced, special care had to be done to coordinate the
freeing of the file meta data with the files that are exposed to user
space. The file meta data would have a ref count that is set when the file
is created and would be decremented and freed after the last user that
opened the file closed it. When the file meta data was to be freed, it
would set a flag (EVENT_FILE_FL_FREED) to denote that the file is freed,
and any new references made (like new opens or reads) would fail as it is
marked freed. This allowed other meta data to be freed after this flag was
set (under the event_mutex).
All the files that were dynamically created in the events directory had a
pointer to the file meta data and would call event_release() when the last
reference to the user space file was closed. This would be the time that it
is safe to free the file meta data.
A shortcut was made for the "format" file. It's i_private would point to
the "call" entry directly and not point to the file's meta data. This is
because all format files are the same for the same "call", so it was
thought there was no reason to differentiate them. The other files
maintain state (like the "enable", "trigger", etc). But this meant if the
file were to disappear, the "format" file would be unaware of it.
This caused a race that could be trigger via the user_events test (that
would create dynamic events and free them), and running a loop that would
read the user_events format files:
In one console run:
# cd tools/testing/selftests/user_events
# while true; do ./ftrace_test; done
And in another console run:
# cd /sys/kernel/tracing/
# while true; do cat events/user_events/__test_event/format; done 2>/dev/null
With KASAN memory checking, it would trigger a use-after-free bug report
(which was a real bug). This was because the format file was not checking
the file's meta data flag "EVENT_FILE_FL_FREED", so it would access the
event that the file meta data pointed to after the event was freed.
After inspection, there are other locations that were found to not check
the EVENT_FILE_FL_FREED flag when accessing the trace_event_file. Add a
new helper function: event_file_file() that will make sure that the
event_mutex is held, and will return NULL if the trace_event_file has the
EVENT_FILE_FL_FREED flag set. Have the first reference of the struct file
pointer use event_file_file() and check for NULL. Later uses can still use
the event_file_data() helper function if the event_mutex is still held and
was not released since the event_file_file() call.
Link: https://lore.kernel.org/all/20240719204701.1605950-1-minipli@grsecurity.net/
Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Ajay Kaher <ajay.kaher@broadcom.com>
Cc: Ilkka Naulapää <digirigawa@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Dan Carpenter <dan.carpenter@linaro.org>
Cc: Beau Belgrave <beaub@linux.microsoft.com>
Cc: Florian Fainelli <florian.fainelli@broadcom.com>
Cc: Alexey Makhalov <alexey.makhalov@broadcom.com>
Cc: Vasavi Sirnapalli <vasavi.sirnapalli@broadcom.com>
Link: https://lore.kernel.org/20240730110657.3b69d3c1@gandalf.local.home
Fixes: b63db58e2f ("eventfs/tracing: Add callback for release of an eventfs_inode")
Reported-by: Mathias Krause <minipli@grsecurity.net>
Tested-by: Mathias Krause <minipli@grsecurity.net>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Currently, whenever a caller is providing an affinity hint for an
interrupt, the allocation code uses it to calculate the node and copies the
cpumask into irq_desc::affinity.
If the affinity for the interrupt is not marked 'managed' then the startup
of the interrupt ignores irq_desc::affinity and uses the system default
affinity mask.
Prevent this by setting the IRQD_AFFINITY_SET flag for the interrupt in the
allocator, which causes irq_setup_affinity() to use irq_desc::affinity on
interrupt startup if the mask contains an online CPU.
[ tglx: Massaged changelog ]
Fixes: 45ddcecbfa ("genirq: Use affinity hint in irqdesc allocation")
Signed-off-by: Shay Drory <shayd@nvidia.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/all/20240806072044.837827-1-shayd@nvidia.com
Currently the dma debugging code can end up indirectly calling printk
under the radix_lock. This happens when a radix tree node allocation
fails.
This is a problem because the printk code, when used together with
netconsole, can end up inside the dma debugging code while trying to
transmit a message over netcons.
This creates the possibility of either a circular deadlock on the same
CPU, with that CPU trying to grab the radix_lock twice, or an ABBA
deadlock between different CPUs, where one CPU grabs the console lock
first and then waits for the radix_lock, while the other CPU is holding
the radix_lock and is waiting for the console lock.
The trace captured by lockdep is of the ABBA variant.
-> #2 (&dma_entry_hash[i].lock){-.-.}-{2:2}:
_raw_spin_lock_irqsave+0x5a/0x90
debug_dma_map_page+0x79/0x180
dma_map_page_attrs+0x1d2/0x2f0
bnxt_start_xmit+0x8c6/0x1540
netpoll_start_xmit+0x13f/0x180
netpoll_send_skb+0x20d/0x320
netpoll_send_udp+0x453/0x4a0
write_ext_msg+0x1b9/0x460
console_flush_all+0x2ff/0x5a0
console_unlock+0x55/0x180
vprintk_emit+0x2e3/0x3c0
devkmsg_emit+0x5a/0x80
devkmsg_write+0xfd/0x180
do_iter_readv_writev+0x164/0x1b0
vfs_writev+0xf9/0x2b0
do_writev+0x6d/0x110
do_syscall_64+0x80/0x150
entry_SYSCALL_64_after_hwframe+0x4b/0x53
-> #0 (console_owner){-.-.}-{0:0}:
__lock_acquire+0x15d1/0x31a0
lock_acquire+0xe8/0x290
console_flush_all+0x2ea/0x5a0
console_unlock+0x55/0x180
vprintk_emit+0x2e3/0x3c0
_printk+0x59/0x80
warn_alloc+0x122/0x1b0
__alloc_pages_slowpath+0x1101/0x1120
__alloc_pages+0x1eb/0x2c0
alloc_slab_page+0x5f/0x150
new_slab+0x2dc/0x4e0
___slab_alloc+0xdcb/0x1390
kmem_cache_alloc+0x23d/0x360
radix_tree_node_alloc+0x3c/0xf0
radix_tree_insert+0xf5/0x230
add_dma_entry+0xe9/0x360
dma_map_page_attrs+0x1d2/0x2f0
__bnxt_alloc_rx_frag+0x147/0x180
bnxt_alloc_rx_data+0x79/0x160
bnxt_rx_skb+0x29/0xc0
bnxt_rx_pkt+0xe22/0x1570
__bnxt_poll_work+0x101/0x390
bnxt_poll+0x7e/0x320
__napi_poll+0x29/0x160
net_rx_action+0x1e0/0x3e0
handle_softirqs+0x190/0x510
run_ksoftirqd+0x4e/0x90
smpboot_thread_fn+0x1a8/0x270
kthread+0x102/0x120
ret_from_fork+0x2f/0x40
ret_from_fork_asm+0x11/0x20
This bug is more likely than it seems, because when one CPU has run out
of memory, chances are the other has too.
The good news is, this bug is hidden behind the CONFIG_DMA_API_DEBUG, so
not many users are likely to trigger it.
Signed-off-by: Rik van Riel <riel@surriel.com>
Reported-by: Konstantin Ovsepian <ovs@meta.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
The addition of the bases argument to clock_was_set() fixed up all call
sites correctly except for do_adjtimex(). This uses CLOCK_REALTIME
instead of CLOCK_SET_WALL as argument. CLOCK_REALTIME is 0.
As a result the effect of that clock_was_set() notification is incomplete
and might result in timers expiring late because the hrtimer code does
not re-evaluate the affected clock bases.
Use CLOCK_SET_WALL instead of CLOCK_REALTIME to tell the hrtimers code
which clock bases need to be re-evaluated.
Fixes: 17a1b8826b ("hrtimer: Add bases argument to clock_was_set()")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/all/877ccx7igo.ffs@tglx
Using syzkaller with the recently reintroduced signed integer overflow
sanitizer produces this UBSAN report:
UBSAN: signed-integer-overflow in ../kernel/time/ntp.c:738:18
9223372036854775806 + 4 cannot be represented in type 'long'
Call Trace:
handle_overflow+0x171/0x1b0
__do_adjtimex+0x1236/0x1440
do_adjtimex+0x2be/0x740
The user supplied time_constant value is incremented by four and then
clamped to the operating range.
Before commit eea83d896e ("ntp: NTP4 user space bits update") the user
supplied value was sanity checked to be in the operating range. That change
removed the sanity check and relied on clamping after incrementing which
does not work correctly when the user supplied value is in the overflow
zone of the '+ 4' operation.
The operation requires CAP_SYS_TIME and the side effect of the overflow is
NTP getting out of sync.
Similar to the fixups for time_maxerror and time_esterror, clamp the user
space supplied value to the operating range.
[ tglx: Switch to clamping ]
Fixes: eea83d896e ("ntp: NTP4 user space bits update")
Signed-off-by: Justin Stitt <justinstitt@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Miroslav Lichvar <mlichvar@redhat.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/all/20240517-b4-sio-ntp-c-v2-1-f3a80096f36f@google.com
Closes: https://github.com/KSPP/linux/issues/352
Using syzkaller alongside the newly reintroduced signed integer overflow
sanitizer spits out this report:
UBSAN: signed-integer-overflow in ../kernel/time/ntp.c:461:16
9223372036854775807 + 500 cannot be represented in type 'long'
Call Trace:
handle_overflow+0x171/0x1b0
second_overflow+0x2d6/0x500
accumulate_nsecs_to_secs+0x60/0x160
timekeeping_advance+0x1fe/0x890
update_wall_time+0x10/0x30
time_maxerror is unconditionally incremented and the result is checked
against NTP_PHASE_LIMIT, but the increment itself can overflow, resulting
in wrap-around to negative space.
Before commit eea83d896e ("ntp: NTP4 user space bits update") the user
supplied value was sanity checked to be in the operating range. That change
removed the sanity check and relied on clamping in handle_overflow() which
does not work correctly when the user supplied value is in the overflow
zone of the '+ 500' operation.
The operation requires CAP_SYS_TIME and the side effect of the overflow is
NTP getting out of sync.
Miroslav confirmed that the input value should be clamped to the operating
range and the same applies to time_esterror. The latter is not used by the
kernel, but the value still should be in the operating range as it was
before the sanity check got removed.
Clamp them to the operating range.
[ tglx: Changed it to clamping and included time_esterror ]
Fixes: eea83d896e ("ntp: NTP4 user space bits update")
Signed-off-by: Justin Stitt <justinstitt@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Miroslav Lichvar <mlichvar@redhat.com>
Link: https://lore.kernel.org/all/20240517-b4-sio-ntp-usec-v2-1-d539180f2b79@google.com
Closes: https://github.com/KSPP/linux/issues/354
The kernel sleep profile is no longer working due to a recursive locking
bug introduced by commit 42a20f86dc ("sched: Add wrapper for get_wchan()
to keep task blocked")
Booting with the 'profile=sleep' kernel command line option added or
executing
# echo -n sleep > /sys/kernel/profiling
after boot causes the system to lock up.
Lockdep reports
kthreadd/3 is trying to acquire lock:
ffff93ac82e08d58 (&p->pi_lock){....}-{2:2}, at: get_wchan+0x32/0x70
but task is already holding lock:
ffff93ac82e08d58 (&p->pi_lock){....}-{2:2}, at: try_to_wake_up+0x53/0x370
with the call trace being
lock_acquire+0xc8/0x2f0
get_wchan+0x32/0x70
__update_stats_enqueue_sleeper+0x151/0x430
enqueue_entity+0x4b0/0x520
enqueue_task_fair+0x92/0x6b0
ttwu_do_activate+0x73/0x140
try_to_wake_up+0x213/0x370
swake_up_locked+0x20/0x50
complete+0x2f/0x40
kthread+0xfb/0x180
However, since nobody noticed this regression for more than two years,
let's remove 'profile=sleep' support based on the assumption that nobody
needs this functionality.
Fixes: 42a20f86dc ("sched: Add wrapper for get_wchan() to keep task blocked")
Cc: stable@vger.kernel.org # v5.16+
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull timer fixes from Thomas Gleixner:
"Two fixes for the timer/clocksource code:
- The recent fix to make the take over of the broadcast timer more
reliable retrieves a per CPU pointer in preemptible context.
This went unnoticed in testing as some compilers hoist the access
into the non-preemotible section where the pointer is actually
used, but obviously compilers can rightfully invoke it where the
code put it.
Move it into the non-preemptible section right to the actual usage
side to cure it.
- The clocksource watchdog is supposed to emit a warning when the
retry count is greater than one and the number of retries reaches
the limit.
The condition is backwards and warns always when the count is
greater than one. Fixup the condition to prevent spamming dmesg"
* tag 'timers-urgent-2024-08-04' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
clocksource: Fix brown-bag boolean thinko in cs_watchdog_read()
tick/broadcast: Move per CPU pointer access into the atomic section
Pull scheduler fixes from Thomas Gleixner:
- When stime is larger than rtime due to accounting imprecision, then
utime = rtime - stime becomes negative. As this is unsigned math, the
result becomes a huge positive number.
Cure it by resetting stime to rtime in that case, so utime becomes 0.
- Restore consistent state when sched_cpu_deactivate() fails.
When offlining a CPU fails in sched_cpu_deactivate() after the SMT
present counter has been decremented, then the function aborts but
fails to increment the SMT present counter and leaves it imbalanced.
Consecutive operations cause it to underflow. Add the missing fixup
for the error path.
For SMT accounting the runqueue needs to marked online again in the
error exit path to restore consistent state.
* tag 'sched-urgent-2024-08-04' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/core: Fix unbalance set_rq_online/offline() in sched_cpu_deactivate()
sched/core: Introduce sched_set_rq_on/offline() helper
sched/smt: Fix unbalance sched_smt_present dec/inc
sched/smt: Introduce sched_smt_present_inc/dec() helper
sched/cputime: Fix mul_u64_u64_div_u64() precision for cputime
Pull locking fixes from Thomas Gleixner:
"Two fixes for locking and jump labels:
- Ensure that the atomic_cmpxchg() conditions are correct and
evaluating to true on any non-zero value except 1. The missing
check of the return value leads to inconsisted state of the jump
label counter.
- Add a missing type conversion in the paravirt spinlock code which
makes loongson build again"
* tag 'locking-urgent-2024-08-04' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
jump_label: Fix the fix, brown paper bags galore
locking/pvqspinlock: Correct the type of "old" variable in pv_kick_node()
The current "nretries > 1 || nretries >= max_retries" check in
cs_watchdog_read() will always evaluate to true, and thus pr_warn(), if
nretries is greater than 1. The intent is instead to never warn on the
first try, but otherwise warn if the successful retry was the last retry.
Therefore, change that "||" to "&&".
Fixes: db3a34e174 ("clocksource: Retry clock read if long delays detected")
Reported-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/all/20240802154618.4149953-2-paulmck@kernel.org
