commit c74ba8b348 ("arch: Introduce post-init read-only memory")
introduced the __ro_after_init attribute which allows to add variables
to the ro_after_init data section.
This new section was added to rodata, even though it contains writable
data. This in turn causes problems on architectures which mark the
page table entries read-only that point to rodata very early.
This patch allows architectures to implement an own handling of the
.data..ro_after_init section.
Usually that would be:
- mark the rodata section read-only very early
- mark the ro_after_init section read-only within mark_rodata_ro
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
ptep_flush_lazy and pmdp_flush_lazy use mm->context.attach_count to
decide between a lazy TLB flush vs an immediate TLB flush. The field
contains two 16-bit counters, the number of CPUs that have the mm
attached and can create TLB entries for it and the number of CPUs in
the middle of a page table update.
The __tlb_flush_asce, ptep_flush_direct and pmdp_flush_direct functions
use the attach counter and a mask check with mm_cpumask(mm) to decide
between a local flush local of the current CPU and a global flush.
For all these functions the decision between lazy vs immediate and
local vs global TLB flush can be based on CPU masks. There are two
masks: the mm->context.cpu_attach_mask with the CPUs that are actively
using the mm, and the mm_cpumask(mm) with the CPUs that have used the
mm since the last full flush. The decision between lazy vs immediate
flush is based on the mm->context.cpu_attach_mask, to decide between
local vs global flush the mm_cpumask(mm) is used.
With this patch all checks will use the CPU masks, the old counter
mm->context.attach_count with its two 16-bit values is turned into a
single counter mm->context.flush_count that keeps track of the number
of CPUs with incomplete page table updates. The sole user of this
counter is finish_arch_post_lock_switch() which waits for the end of
all page table updates.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The bitmap_equal function has optimized code for small bitmaps with less
than BITS_PER_LONG bits. For larger bitmaps the out-of-line function
__bitmap_equal is called.
For a constant number of bits divisible by BITS_PER_LONG the memcmp
function can be used. For s390 gcc knows how to optimize this function,
memcmp calls with up to 256 bytes / 2048 bits are translated into a
single instruction.
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The vunmap_pte_range() function calls ptep_get_and_clear() without any
locking. ptep_get_and_clear() uses ptep_xchg_lazy()/ptep_flush_direct()
for the page table update. ptep_flush_direct requires that preemption
is disabled, but without any locking this is not the case. If the kernel
preempts the task while the attach_counter is increased an endless loop
in finish_arch_post_lock_switch() will occur the next time the task is
scheduled.
Add explicit preempt_disable()/preempt_enable() calls to the relevant
functions in arch/s390/mm/pgtable.c.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The External-Time-Reference (ETR) clock synchronization interface has
been superseded by Server-Time-Protocol (STP). Remove the outdated
ETR interface.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The PTFF instruction can be used to retrieve information about UTC
including the current number of leap seconds. Use this value to
convert the coordinated server time value of the TOD clock to a
proper UTC timestamp to initialize the system time. Without this
correction the system time will be off by the number of leap seonds
until it has been corrected via NTP.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
It is possible to specify a user offset for the TOD clock, e.g. +2 hours.
The TOD clock will carry this offset even if the clock is synchronized
with STP. This makes the time stamps acquired with get_sync_clock()
useless as another LPAR migth use a different TOD offset.
Use the PTFF instrution to get the TOD epoch difference and subtract
it from the TOD clock value to get a physical timestamp. As the epoch
difference contains the sync check delta as well the LPAR offset value
to the physical clock needs to be refreshed after each clock
synchronization.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The PTFF instruction is not a function of ETR, rename and move the
PTFF definitions from etr.h to timex.h.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The sync clock operation of the channel subsystem call for STP delivers
the TOD clock difference as a result. Use this TOD clock difference
instead of the difference between the TOD timestamps before and after
the sync clock operation.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Reducing the size of reserved memory for the crash kernel will result
in an immediate crash on s390. Reason for that is that we do not
create struct pages for memory that is reserved. If that memory is
freed any access to struct pages which correspond to this memory will
result in invalid memory accesses and a kernel panic.
Fix this by properly creating struct pages when the system gets
initialized. Change the code also to make use of set_memory_ro() and
set_memory_rw() so page tables will be split if required.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Implement an s390 version of the weak crash_free_reserved_phys_range
function. This allows us to update the size of the reserved crash
kernel memory if it will be resized.
This was previously done with a call to crash_unmap_reserved_pages
from crash_shrink_memory which was removed with ("s390/kexec:
consolidate crash_map/unmap_reserved_pages() and
arch_kexec_protect(unprotect)_crashkres()")
Fixes: 7a0058ec78 ("s390/kexec: consolidate crash_map/unmap_reserved_pages() and arch_kexec_protect(unprotect)_crashkres()")
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The segment/region table that is part of the kernel image must be
properly aligned to 16k in order to make the crdte inline assembly
work.
Otherwise it will calculate a wrong segment/region table start address
and access incorrect memory locations if the swapper_pg_dir is not
aligned to 16k.
Therefore define BSS_FIRST_SECTIONS in order to put the swapper_pg_dir
at the beginning of the bss section and also align the bss section to
16k just like other architectures did.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Lets provide the basic machine information for dump_stack on
s390. This enables the "Hardware name:" line and results in
output like
[...]
Oops: 0004 ilc:2 [#1] SMP
Modules linked in:
CPU: 1 PID: 74 Comm: sh Not tainted 4.5.0+ #205
Hardware name: IBM 2964 NC9 704 (KVM)
[...]
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Show the dynamic and static cpu mhz of each cpu. Since these values
are per cpu this requires a fundamental extension of the format of
/proc/cpuinfo.
Historically we had only a single line per cpu and a summary at the
top of the file. This format is hardly extendible if we want to add
more per cpu information.
Therefore this patch adds per cpu blocks at the end of /proc/cpuinfo:
cpu : 0
cpu Mhz dynamic : 5504
cpu Mhz static : 5504
cpu : 1
cpu Mhz dynamic : 5504
cpu Mhz static : 5504
cpu : 2
cpu Mhz dynamic : 5504
cpu Mhz static : 5504
cpu : 3
cpu Mhz dynamic : 5504
cpu Mhz static : 5504
Right now each block contains only the dynamic and static cpu mhz,
but it can be easily extended like on every other architecture.
This extension is supposed to be compatible with the old format.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: Sascha Silbe <silbe@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Change the code to print all the current output during the first
iteration. This is a preparation patch for the upcoming per cpu block
extension to /proc/cpuinfo.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Add statistics that show how memory is mapped within the kernel
identity mapping. This is more or less the same like git
commit ce0c0e50f9 ("x86, generic: CPA add statistics about state
of direct mapping v4") for x86.
I also intentionally copied the lower case "k" within DirectMap4k vs
the upper case "M" and "G" within the two other lines. Let's have
consistent inconsistencies across architectures.
The output of /proc/meminfo now contains these additional lines:
DirectMap4k: 2048 kB
DirectMap1M: 3991552 kB
DirectMap2G: 4194304 kB
The implementation on s390 is lockless unlike the x86 version, since I
assume changes to the kernel mapping are a very rare event. Therefore
it really doesn't matter if these statistics could potentially be
inconsistent if read while kernel pages tables are being changed.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
For the kernel identity mapping map everything read-writeable and
subsequently call set_memory_ro() to make the ro section read-only.
This simplifies the code a lot.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
set_memory_ro() and set_memory_rw() currently only work on 4k
mappings, which is good enough for module code aka the vmalloc area.
However we stumbled already twice into the need to make this also work
on larger mappings:
- the ro after init patch set
- the crash kernel resize code
Therefore this patch implements automatic kernel page table splitting
if e.g. set_memory_ro() would be called on parts of a 2G mapping.
This works quite the same as the x86 code, but is much simpler.
In order to make this work and to be architecturally compliant we now
always use the csp, cspg or crdte instructions to replace valid page
table entries. This means that set_memory_ro() and set_memory_rw()
will be much more expensive than before. In order to avoid huge
latencies the code contains a couple of cond_resched() calls.
The current code only splits page tables, but does not merge them if
it would be possible. The reason for this is that currently there is
no real life scenarion where this would really happen. All current use
cases that I know of only change access rights once during the life
time. If that should change we can still implement kernel page table
merging at a later time.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Make pmd_wrprotect() and pmd_mkwrite() available independently from
CONFIG_TRANSPARENT_HUGEPAGE and CONFIG_HUGETLB_PAGE so these can be
used on the kernel mapping.
Also introduce a couple of pud helper functions, namely pud_pfn(),
pud_wrprotect(), pud_mkwrite(), pud_mkdirty() and pud_mkclean()
which only work on the kernel mapping.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Always use PAGE_KERNEL when re-enabling pages within the kernel
mapping due to debug pagealloc. Without using this pgprot value
pte_mkwrite() and pte_wrprotect() won't work on such mappings after an
unmap -> map cycle anymore.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Instead of open-coded SEGMENT_KERNEL and REGION3_KERNEL assignments use
defines. Also to make e.g. pmd_wrprotect() work on the kernel mapping
a couple more flags must be set. Therefore add the missing flags also.
In order to make everything symmetrical this patch also adds software
dirty, young, read and write bits for region 3 table entries.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Usually segment and region tables are 16k aligned due to the way the
buddy allocator works. This is not true for the vmem code which only
asks for a 4k alignment. In order to be consistent enforce a 16k
alignment here as well.
This alignment will be assumed and therefore is required by the
pageattr code.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
We have already two inline assemblies which make use of the csp
instruction. Since I need a third instance let's introduce a generic
inline assmebly which can be used by everyone.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Use memdup_user_nul to duplicate a memory region from user-space
to kernel-space and terminate with a NULL, instead of open coding
using kmalloc + copy_from_user and explicitly NULL terminating.
Signed-off-by: Muhammad Falak R Wani <falakreyaz@gmail.com>
[heiko.carstens@de.ibm.com: remove comment]
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
commit 1e133ab296 ("s390/mm: split arch/s390/mm/pgtable.c") factored
out the page table handling code from __gmap_zap and __s390_reset_cmma
into ptep_zap_unused and added a simple flag that tells which one of the
function (reset or not) is to be made. This also changed the behaviour,
as it also zaps unused page table entries on reset.
Turns out that this is wrong as s390_reset_cmma uses the page walker,
which DOES NOT take the ptl lock.
The most simple fix is to not do the zapping part on reset (which uses
the walker)
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Fixes: 1e133ab296 ("s390/mm: split arch/s390/mm/pgtable.c")
Cc: stable@vger.kernel.org # 4.6+
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Pull thermal management fixes from Zhang Rui:
- fix an ordering issue in cpu cooling that cooling device is
registered before it's ready (freq_table being populated).
(Lukasz Luba)
- fix a missing comment update (Caesar Wang)
* 'for-rc' of git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linux:
thermal: add the note for set_trip_temp
thermal: cpu_cooling: fix improper order during initialization
Pull block layer fixes from Jens Axboe:
"A small collection of fixes for the current series. This contains:
- Two fixes for xen-blkfront, from Bob Liu.
- A bug fix for NVMe, releasing only the specific resources we
requested.
- Fix for a debugfs flags entry for nbd, from Josef.
- Plug fix from Omar, fixing up a case of code being switched between
two functions.
- A missing bio_put() for the new discard callers of
submit_bio_wait(), fixing a regression causing a leak of the bio.
From Shaun.
- Improve dirty limit calculation precision in the writeback code,
fixing a case where setting a limit lower than 1% of memory would
end up being zero. From Tejun"
* 'for-linus' of git://git.kernel.dk/linux-block:
NVMe: Only release requested regions
xen-blkfront: fix resume issues after a migration
xen-blkfront: don't call talk_to_blkback when already connected to blkback
nbd: pass the nbd pointer for flags debugfs
block: missing bio_put following submit_bio_wait
blk-mq: really fix plug list flushing for nomerge queues
writeback: use higher precision calculation in domain_dirty_limits()
Pull GPIO fixes from Linus Walleij:
"A new bunch of GPIO fixes for v4.7.
This time I am very grateful that Ricardo Ribalda Delgado went in and
fixed my stupid refcounting mistakes in the removal path for GPIO
chips. I had a feeling something was wrong here and so it was. It
exploded on OMAP and it fixes their problem. Now it should be (more)
solid.
The rest i compilation, Kconfig and driver fixes. Some tagged for
stable.
Summary:
- Fix a NULL pointer dereference when we are searching the GPIO
device list but one of the devices have been removed (struct
gpio_chip pointer is NULL).
- Fix unaligned reference counters: we were ending on +3 after all
said and done. It should be 0. Remove an extraneous get_device(),
and call cdev_del() followed by device_del() in gpiochip_remove()
instead and the count goes to zero and calls the release() function
properly.
- Fix a compile warning due to a missing #include in the OF/device
tree portions.
- Select ANON_INODES for GPIOLIB, we're using that for our character
device. Some randconfig tests disclosed the problem.
- Make sure the Zynq driver clock runs also without CONFIG_PM enabled
- Fix an off-by-one error in the 104-DIO-48E driver
- Fix warnings in bcm_kona_gpio_reset()"
* tag 'gpio-v4.7-3' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio:
gpio: bcm-kona: fix bcm_kona_gpio_reset() warnings
gpio: select ANON_INODES
gpio: include <linux/io-mapping.h> in gpiolib-of
gpiolib: Fix unaligned used of reference counters
gpiolib: Fix NULL pointer deference
gpio: zynq: initialize clock even without CONFIG_PM
gpio: 104-dio-48e: Fix control port offset computation off-by-one error
Pull SCSI fixes from James Bottomley:
"Two current fixes:
- one affects Qemu CD ROM emulation, which stopped working after the
updates in SCSI to require VPD pages from all conformant devices.
Fix temporarily by blacklisting Qemu (we can relax later when they
come into compliance).
- The other is a fix to the optimal transfer size. We set up a
minefield for ourselves by being confused about whether the limits
are in bytes or sectors (SCSI optimal is in blocks and the queue
parameter is in bytes).
This tries to fix the problem (wrong setting for queue limits
max_sectors) and make the problem more obvious by introducing a
wrapper function"
* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
sd: Fix rw_max for devices that report an optimal xfer size
scsi: Add QEMU CD-ROM to VPD Inquiry Blacklist
Pull i2c fixes from Wolfram Sang:
- a bigger fix for i801 to finally be able to be loaded on some
machines again
- smaller driver fixes
- documentation update because of a renamed file
* 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
i2c: mux: reg: Provide of_match_table
i2c: mux: refer to i2c-mux.txt
i2c: octeon: Avoid printk after too long SMBUS message
i2c: octeon: Missing AAK flag in case of I2C_M_RECV_LEN
i2c: i801: Allow ACPI SystemIO OpRegion to conflict with PCI BAR
Pull DeviceTree fixes from Rob Herring:
- fix unflatten_dt_nodes when dad parameter is set.
- add vendor prefixes for TechNexion and UniWest
- documentation fix for Marvell BT
- OF IRQ kerneldoc fixes
- restrict CMA alignment adjustments to non dma-coherent
- a couple of warning fixes in reserved-memory code
- DT maintainers updates
* tag 'devicetree-fixes-for-4.7' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux:
drivers: of: add definition of early_init_dt_alloc_reserved_memory_arch
drivers/of: Fix depth for sub-tree blob in unflatten_dt_nodes()
drivers: of: Fix of_pci.h header guard
dt-bindings: Add vendor prefix for TechNexion
of: add vendor prefix for UniWest
dt: bindings: fix documentation for MARVELL's bt-sd8xxx wireless device
of: add missing const for of_parse_phandle_with_args() in !CONFIG_OF
of: silence warnings due to max() usage
drivers: of: of_reserved_mem: fixup the CMA alignment not to affect dma-coherent
of: irq: fix of_irq_get[_byname]() kernel-doc
MAINTAINERS: DeviceTree maintainer updates
Pull uvc compat XU ioctl fixes from Andy Lutomirski:
"uvc's compat XU ioctls go through tons of potentially buggy
indirection. The first patch removes the indirection. The second one
cleans up the code.
Compile-tested only. I have the hardware, but I have absolutely no
idea what XU does, how to use it, what software to recompile as
32-bit, or what to test in that software"
* tag '20160610_uvc_compat_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/luto/linux:
uvc_v4l2: Simplify compat ioctl implementation
uvc: Forward compat ioctls to their handlers directly
The uvc compat ioctl implementation seems to have copied user data
for no good reason. Remove a bunch of copies.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
The current code goes through a lot of indirection just to call a
known handler. Simplify it: just call the handlers directly.
Cc: stable@vger.kernel.org
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Pull btrfs fixes from Chris Mason:
"Has some fixes and some new self tests for btrfs. The self tests are
usually disabled in the .config file (unless you're doing btrfs dev
work), and this bunch is meant to find problems with the 64K page size
patches.
Jeff has a patch to help people see if they are using the hardware
assist crc32c module, which really helps us nail down problems when
people ask why crcs are using so much CPU.
Otherwise, it's small fixes"
* 'for-linus-4.7' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
Btrfs: self-tests: Fix extent buffer bitmap test fail on BE system
Btrfs: self-tests: Fix test_bitmaps fail on 64k sectorsize
Btrfs: self-tests: Use macros instead of constants and add missing newline
Btrfs: self-tests: Support testing all possible sectorsizes and nodesizes
Btrfs: self-tests: Execute page straddling test only when nodesize < PAGE_SIZE
btrfs: advertise which crc32c implementation is being used at module load
Btrfs: add validadtion checks for chunk loading
Btrfs: add more validation checks for superblock
Btrfs: clear uptodate flags of pages in sys_array eb
Btrfs: self-tests: Support non-4k page size
Btrfs: Fix integer overflow when calculating bytes_per_bitmap
Btrfs: test_check_exists: Fix infinite loop when searching for free space entries
Btrfs: end transaction if we abort when creating uuid root
btrfs: Use __u64 in exported linux/btrfs.h.
Pull powerpc fixes from
- ptrace: Fix out of bounds array access warning from Khem Raj
- pseries: Fix PCI config address for DDW from Gavin Shan
- pseries: Fix IBM_ARCH_VEC_NRCORES_OFFSET since POWER8NVL was added
from Michael Ellerman
- of: fix autoloading due to broken modalias with no 'compatible' from
Wolfram Sang
- radix: Fix always false comparison against MMU_NO_CONTEXT from Aneesh
Kumar K.V
- hash: Compute the segment size correctly for ISA 3.0 from Aneesh
Kumar K.V
- nohash: Fix build break with 64K pages from Michael Ellerman
* tag 'powerpc-4.7-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
powerpc/nohash: Fix build break with 64K pages
powerpc/mm/hash: Compute the segment size correctly for ISA 3.0
powerpc/mm/radix: Fix always false comparison against MMU_NO_CONTEXT
of: fix autoloading due to broken modalias with no 'compatible'
powerpc/pseries: Fix IBM_ARCH_VEC_NRCORES_OFFSET since POWER8NVL was added
powerpc/pseries: Fix PCI config address for DDW
powerpc/ptrace: Fix out of bounds array access warning
Pull hwmon fixes from Guenter Roeck:
- fix regression in fam15h_power driver
- minor variable type fix in lm90 driver
- document compatible statement for ina2xx driver
* tag 'hwmon-for-linus-v4.7-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging:
hwmon: (lm90) use proper type for update_interval
hwmon: (ina2xx) Document compatible for INA231
hwmon: (fam15h_power) Disable preemption when reading registers
Merge filesystem stacking fixes from Jann Horn.
* emailed patches from Jann Horn <jannh@google.com>:
sched: panic on corrupted stack end
ecryptfs: forbid opening files without mmap handler
proc: prevent stacking filesystems on top
Until now, hitting this BUG_ON caused a recursive oops (because oops
handling involves do_exit(), which calls into the scheduler, which in
turn raises an oops), which caused stuff below the stack to be
overwritten until a panic happened (e.g. via an oops in interrupt
context, caused by the overwritten CPU index in the thread_info).
Just panic directly.
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This prevents stacking filesystems (ecryptfs and overlayfs) from using
procfs as lower filesystem. There is too much magic going on inside
procfs, and there is no good reason to stack stuff on top of procfs.
(For example, procfs does access checks in VFS open handlers, and
ecryptfs by design calls open handlers from a kernel thread that doesn't
drop privileges or so.)
Signed-off-by: Jann Horn <jannh@google.com>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull arm64 fix from Will Deacon:
"A fix for an issue that Alex saw whilst swapping with hardware
access/dirty bit support enabled in the kernel: Fix a failure to fault
in old pages on a write when CONFIG_ARM64_HW_AFDBM is enabled"
* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
arm64: mm: always take dirty state from new pte in ptep_set_access_flags
Pull x86 fixes from Ingo Molnar:
"Misc fixes from all around the map, plus a commit that introduces a
new header of Intel model name symbols (unused) that will make the
next merge window easier"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/ioapic: Fix incorrect pointers in ioapic_setup_resources()
x86/entry/traps: Don't force in_interrupt() to return true in IST handlers
x86/cpu/AMD: Extend X86_FEATURE_TOPOEXT workaround to newer models
x86/cpu/intel: Introduce macros for Intel family numbers
x86, build: copy ldlinux.c32 to image.iso
x86/msr: Use the proper trace point conditional for writes
Pull perf fixes from Ingo Molnar:
"A handful of tooling fixes, two PMU driver fixes and a cleanup of
redundant code that addresses a security analyzer false positive"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/core: Remove a redundant check
perf/x86/intel/uncore: Remove SBOX support for Broadwell server
perf ctf: Convert invalid chars in a string before set value
perf record: Fix crash when kptr is restricted
perf symbols: Check kptr_restrict for root
perf/x86/intel/rapl: Fix pmus free during cleanup
