| Age | Commit message (Collapse) | Author |
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smp_rescan_cpus() is called without the device_hotplug_lock, which can lead
to a dedlock when a new CPU is found and immediately set online by a udev
rule.
This was observed on an older kernel version, where the cpu_hotplug_begin()
loop was still present, and it resulted in hanging chcpu and systemd-udev
processes. This specific deadlock will not show on current kernels. However,
there may be other possible deadlocks, and since smp_rescan_cpus() can still
trigger a CPU hotplug operation, the device_hotplug_lock should be held.
For reference, this was the deadlock with the old cpu_hotplug_begin() loop:
chcpu (rescan) systemd-udevd
echo 1 > /sys/../rescan
-> smp_rescan_cpus()
-> (*) get_online_cpus()
(increases refcount)
-> smp_add_present_cpu()
(new CPU found)
-> register_cpu()
-> device_add()
-> udev "add" event triggered -----------> udev rule sets CPU online
-> echo 1 > /sys/.../online
-> lock_device_hotplug_sysfs()
(this is missing in rescan path)
-> device_online()
-> (**) device_lock(new CPU dev)
-> cpu_up()
-> cpu_hotplug_begin()
(loops until refcount == 0)
-> deadlock with (*)
-> bus_probe_device()
-> device_attach()
-> device_lock(new CPU dev)
-> deadlock with (**)
Fix this by taking the device_hotplug_lock in the CPU rescan path.
Cc: <stable@vger.kernel.org>
Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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The ASCE of an mm_struct can be modified after a task has been created,
e.g. via crst_table_downgrade for a compat process. The active_mm logic
to avoid the switch_mm call if the next task is a kernel thread can
lead to a situation where switch_mm is called where 'prev == next' is
true but 'prev->context.asce == next->context.asce' is not.
This can lead to a situation where a CPU uses the outdated ASCE to run
a task. The result can be a crash, endless loops and really subtle
problem due to TLBs being created with an invalid ASCE.
Cc: stable@kernel.org # v3.15+
Fixes: 53e857f30867 ("s390/mm,tlb: race of lazy TLB flush vs. recreation")
Reported-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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Right now the early machine detection code check stsi 3.2.2 for "KVM"
and set MACHINE_IS_VM if this is different. As the console detection
uses diagnose 8 if MACHINE_IS_VM returns true this will crash Linux
early for any non z/VM system that sets a different value than KVM.
So instead of assuming z/VM, do not set any of MACHINE_IS_LPAR,
MACHINE_IS_VM, or MACHINE_IS_KVM.
CC: stable@vger.kernel.org
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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Pull VFIO fixes from Alex Williamson:
- Fix trace header include path for in-tree builds (Masahiro Yamada)
- Fix overflow in unmap wrap-around test (Alex Williamson)
* tag 'vfio-v5.0-rc2' of git://github.com/awilliam/linux-vfio:
vfio/type1: Fix unmap overflow off-by-one
vfio/pci: set TRACE_INCLUDE_PATH to fix the build error
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git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound
Pull sound fixes from Takashi Iwai:
"A collection of small fixes for USB-audio, HD-audio and cs46xx.
The USB-audio fixes are for out-of-bound accesses and a regression in
the recent cleanup, while HD-audio fixes are usual device-specific
quirks"
* tag 'sound-5.0-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
ALSA: hda/realtek - Disable headset Mic VREF for headset mode of ALC225
ALSA: hda/realtek - Add unplug function into unplug state of Headset Mode for ALC225
ALSA: usb-audio: fix CM6206 register definitions
ALSA: cs46xx: Potential NULL dereference in probe
ALSA: hda/realtek - Support Dell headset mode for New AIO platform
ALSA: usb-audio: Fix an out-of-bound read in create_composite_quirks
ALSA: usb-audio: Always check descriptor sizes in parser code
ALSA: usb-audio: Check mixer unit descriptors more strictly
ALSA: usb-audio: Avoid access before bLength check in build_audio_procunit()
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Pull mtd fixes from Boris Brezillon:
"Core MTD Fixes:
- Fix a bug introduced when exposing MTD devs as NVMEM providers and
check for add_mtd_device() return code everywhere
raw NAND fixes:
- Fix a memory corruption in the QCOM driver"
* tag 'mtd/fixes-for-5.0-rc2' of git://git.infradead.org/linux-mtd:
mtd: rawnand: qcom: fix memory corruption that causes panic
mtd: Check add_mtd_device() ret code
mtd: Fix the check on nvmem_register() ret code
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This bug is from commit f553aa1c13cb ("csky: fixup relocation error with
807 & 860").
I forgot to compile with 810 for that patch.
Signed-off-by: Guo Ren <ren_guo@c-sky.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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The conversion to use a structure for mmu_notifier_invalidate_range_*()
unintentionally changed the usage in try_to_unmap_one() to init the
'struct mmu_notifier_range' with vma->vm_start instead of @address,
i.e. it invalidates the wrong address range. Revert to the correct
address range.
Manifests as KVM use-after-free WARNINGs and subsequent "BUG: Bad page
state in process X" errors when reclaiming from a KVM guest due to KVM
removing the wrong pages from its own mappings.
Reported-by: leozinho29_eu@hotmail.com
Reported-by: Mike Galbraith <efault@gmx.de>
Reported-and-tested-by: Adam Borowski <kilobyte@angband.pl>
Reviewed-by: Jérôme Glisse <jglisse@redhat.com>
Reviewed-by: Pankaj gupta <pagupta@redhat.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Ross Zwisler <zwisler@kernel.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Felix Kuehling <felix.kuehling@amd.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Fixes: ac46d4f3c432 ("mm/mmu_notifier: use structure for invalidate_range_start/end calls v2")
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Pull arch/csky bug fixes from Guo Ren:
"Here are some fixup patches for 5.0-rc1:
- fix compile error with pte_alloc
- fix handle_irq_perbit break irq flow
- fix CACHEV1 store instruction fast retire
- fix module relocation error with 807 & 860
- add csky kernel features to documentation"
* tag 'csky-for-linus-5.0-rc1' of git://github.com/c-sky/csky-linux:
irqchip/csky: fixup handle_irq_perbit break irq
csky: fixup compile error with pte_alloc
csky: fixup CACHEV1 store instruction fast retire
csky: fixup relocation error with 807 & 860
Documentation/features: Add csky kernel features
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Disable Headset Mic VREF for headset mode of ALC225.
This will be controlled by coef bits of headset mode functions.
[ Fixed a compile warning and code simplification -- tiwai ]
Signed-off-by: Kailang Yang <kailang@realtek.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
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for ALC225
Forgot to add unplug function to unplug state of headset mode
for ALC225.
Signed-off-by: Kailang Yang <kailang@realtek.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
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Merge misc fixes from Andrew Morton:
"14 fixes"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
mm, page_alloc: do not wake kswapd with zone lock held
hugetlbfs: revert "use i_mmap_rwsem for more pmd sharing synchronization"
hugetlbfs: revert "Use i_mmap_rwsem to fix page fault/truncate race"
mm: page_mapped: don't assume compound page is huge or THP
mm/memory.c: initialise mmu_notifier_range correctly
tools/vm/page_owner: use page_owner_sort in the use example
kasan: fix krealloc handling for tag-based mode
kasan: make tag based mode work with CONFIG_HARDENED_USERCOPY
kasan, arm64: use ARCH_SLAB_MINALIGN instead of manual aligning
mm, memcg: fix reclaim deadlock with writeback
mm/usercopy.c: no check page span for stack objects
slab: alien caches must not be initialized if the allocation of the alien cache failed
fork, memcg: fix cached_stacks case
zram: idle writeback fixes and cleanup
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The commit 594cc251fdd0 ("make 'user_access_begin()' do 'access_ok()'")
exposed incorrect implementations of access_ok() macro in several
architectures. This change fixes 2 issues found in OpenRISC.
OpenRISC was not properly using parenthesis for arguments and also using
arguments twice. This patch fixes those 2 issues.
I test booted this patch with v5.0-rc1 on qemu and it's working fine.
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Stafford Horne <shorne@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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syzbot reported the following regression in the latest merge window and
it was confirmed by Qian Cai that a similar bug was visible from a
different context.
======================================================
WARNING: possible circular locking dependency detected
4.20.0+ #297 Not tainted
------------------------------------------------------
syz-executor0/8529 is trying to acquire lock:
000000005e7fb829 (&pgdat->kswapd_wait){....}, at:
__wake_up_common_lock+0x19e/0x330 kernel/sched/wait.c:120
but task is already holding lock:
000000009bb7bae0 (&(&zone->lock)->rlock){-.-.}, at: spin_lock
include/linux/spinlock.h:329 [inline]
000000009bb7bae0 (&(&zone->lock)->rlock){-.-.}, at: rmqueue_bulk
mm/page_alloc.c:2548 [inline]
000000009bb7bae0 (&(&zone->lock)->rlock){-.-.}, at: __rmqueue_pcplist
mm/page_alloc.c:3021 [inline]
000000009bb7bae0 (&(&zone->lock)->rlock){-.-.}, at: rmqueue_pcplist
mm/page_alloc.c:3050 [inline]
000000009bb7bae0 (&(&zone->lock)->rlock){-.-.}, at: rmqueue
mm/page_alloc.c:3072 [inline]
000000009bb7bae0 (&(&zone->lock)->rlock){-.-.}, at:
get_page_from_freelist+0x1bae/0x52a0 mm/page_alloc.c:3491
It appears to be a false positive in that the only way the lock ordering
should be inverted is if kswapd is waking itself and the wakeup
allocates debugging objects which should already be allocated if it's
kswapd doing the waking. Nevertheless, the possibility exists and so
it's best to avoid the problem.
This patch flags a zone as needing a kswapd using the, surprisingly,
unused zone flag field. The flag is read without the lock held to do
the wakeup. It's possible that the flag setting context is not the same
as the flag clearing context or for small races to occur. However, each
race possibility is harmless and there is no visible degredation in
fragmentation treatment.
While zone->flag could have continued to be unused, there is potential
for moving some existing fields into the flags field instead.
Particularly read-mostly ones like zone->initialized and
zone->contiguous.
Link: http://lkml.kernel.org/r/20190103225712.GJ31517@techsingularity.net
Fixes: 1c30844d2dfe ("mm: reclaim small amounts of memory when an external fragmentation event occurs")
Reported-by: syzbot+93d94a001cfbce9e60e1@syzkaller.appspotmail.com
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Tested-by: Qian Cai <cai@lca.pw>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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This reverts b43a9990055958e70347c56f90ea2ae32c67334c
The reverted commit caused issues with migration and poisoning of anon
huge pages. The LTP move_pages12 test will cause an "unable to handle
kernel NULL pointer" BUG would occur with stack similar to:
RIP: 0010:down_write+0x1b/0x40
Call Trace:
migrate_pages+0x81f/0xb90
__ia32_compat_sys_migrate_pages+0x190/0x190
do_move_pages_to_node.isra.53.part.54+0x2a/0x50
kernel_move_pages+0x566/0x7b0
__x64_sys_move_pages+0x24/0x30
do_syscall_64+0x5b/0x180
entry_SYSCALL_64_after_hwframe+0x44/0xa9
The purpose of the reverted patch was to fix some long existing races
with huge pmd sharing. It used i_mmap_rwsem for this purpose with the
idea that this could also be used to address truncate/page fault races
with another patch. Further analysis has determined that i_mmap_rwsem
can not be used to address all these hugetlbfs synchronization issues.
Therefore, revert this patch while working an another approach to the
underlying issues.
Link: http://lkml.kernel.org/r/20190103235452.29335-2-mike.kravetz@oracle.com
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Reported-by: Jan Stancek <jstancek@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: "Aneesh Kumar K . V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Prakash Sangappa <prakash.sangappa@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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This reverts c86aa7bbfd5568ba8a82d3635d8f7b8a8e06fe54
The reverted commit caused ABBA deadlocks when file migration raced with
file eviction for specific hugetlbfs files. This was discovered with a
modified version of the LTP move_pages12 test.
The purpose of the reverted patch was to close a long existing race
between hugetlbfs file truncation and page faults. After more analysis
of the patch and impacted code, it was determined that i_mmap_rwsem can
not be used for all required synchronization. Therefore, revert this
patch while working an another approach to the underlying issue.
Link: http://lkml.kernel.org/r/20190103235452.29335-1-mike.kravetz@oracle.com
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Reported-by: Jan Stancek <jstancek@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: "Aneesh Kumar K . V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Prakash Sangappa <prakash.sangappa@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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LTP proc01 testcase has been observed to rarely trigger crashes
on arm64:
page_mapped+0x78/0xb4
stable_page_flags+0x27c/0x338
kpageflags_read+0xfc/0x164
proc_reg_read+0x7c/0xb8
__vfs_read+0x58/0x178
vfs_read+0x90/0x14c
SyS_read+0x60/0xc0
The issue is that page_mapped() assumes that if compound page is not
huge, then it must be THP. But if this is 'normal' compound page
(COMPOUND_PAGE_DTOR), then following loop can keep running (for
HPAGE_PMD_NR iterations) until it tries to read from memory that isn't
mapped and triggers a panic:
for (i = 0; i < hpage_nr_pages(page); i++) {
if (atomic_read(&page[i]._mapcount) >= 0)
return true;
}
I could replicate this on x86 (v4.20-rc4-98-g60b548237fed) only
with a custom kernel module [1] which:
- allocates compound page (PAGEC) of order 1
- allocates 2 normal pages (COPY), which are initialized to 0xff (to
satisfy _mapcount >= 0)
- 2 PAGEC page structs are copied to address of first COPY page
- second page of COPY is marked as not present
- call to page_mapped(COPY) now triggers fault on access to 2nd COPY
page at offset 0x30 (_mapcount)
[1] https://github.com/jstancek/reproducers/blob/master/kernel/page_mapped_crash/repro.c
Fix the loop to iterate for "1 << compound_order" pages.
Kirrill said "IIRC, sound subsystem can producuce custom mapped compound
pages".
Link: http://lkml.kernel.org/r/c440d69879e34209feba21e12d236d06bc0a25db.1543577156.git.jstancek@redhat.com
Fixes: e1534ae95004 ("mm: differentiate page_mapped() from page_mapcount() for compound pages")
Signed-off-by: Jan Stancek <jstancek@redhat.com>
Debugged-by: Laszlo Ersek <lersek@redhat.com>
Suggested-by: "Kirill A. Shutemov" <kirill@shutemov.name>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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One of the paths in follow_pte_pmd() initialised the mmu_notifier_range
incorrectly.
Link: http://lkml.kernel.org/r/20190103002126.GM6310@bombadil.infradead.org
Fixes: ac46d4f3c432 ("mm/mmu_notifier: use structure for invalidate_range_start/end calls v2")
Signed-off-by: Matthew Wilcox <willy@infradead.org>
Tested-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Jérôme Glisse <jglisse@redhat.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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The example in comment does not useable because the output binary is
named "page_owner_sort", not "sort".
Also add a reference to Documentation/vm/page_owner.rst
Link: http://lkml.kernel.org/r/1546515361-8317-1-git-send-email-miles.chen@mediatek.com
Signed-off-by: Miles Chen <miles.chen@mediatek.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Right now tag-based KASAN can retag the memory that is reallocated via
krealloc and return a differently tagged pointer even if the same slab
object gets used and no reallocated technically happens.
There are a few issues with this approach. One is that krealloc callers
can't rely on comparing the return value with the passed argument to
check whether reallocation happened. Another is that if a caller knows
that no reallocation happened, that it can access object memory through
the old pointer, which leads to false positives. Look at
nf_ct_ext_add() to see an example.
Fix this by keeping the same tag if the memory don't actually gets
reallocated during krealloc.
Link: http://lkml.kernel.org/r/bb2a71d17ed072bcc528cbee46fcbd71a6da3be4.1546540962.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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With CONFIG_HARDENED_USERCOPY enabled __check_heap_object() compares and
then subtracts a potentially tagged pointer with a non-tagged address of
the page that this pointer belongs to, which leads to unexpected
behavior.
Untag the pointer in __check_heap_object() before doing any of these
operations.
Link: http://lkml.kernel.org/r/7e756a298d514c4482f52aea6151db34818d395d.1546540962.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Instead of changing cache->align to be aligned to KASAN_SHADOW_SCALE_SIZE
in kasan_cache_create() we can reuse the ARCH_SLAB_MINALIGN macro.
Link: http://lkml.kernel.org/r/52ddd881916bcc153a9924c154daacde78522227.1546540962.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Suggested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Liu Bo has experienced a deadlock between memcg (legacy) reclaim and the
ext4 writeback
task1:
wait_on_page_bit+0x82/0xa0
shrink_page_list+0x907/0x960
shrink_inactive_list+0x2c7/0x680
shrink_node_memcg+0x404/0x830
shrink_node+0xd8/0x300
do_try_to_free_pages+0x10d/0x330
try_to_free_mem_cgroup_pages+0xd5/0x1b0
try_charge+0x14d/0x720
memcg_kmem_charge_memcg+0x3c/0xa0
memcg_kmem_charge+0x7e/0xd0
__alloc_pages_nodemask+0x178/0x260
alloc_pages_current+0x95/0x140
pte_alloc_one+0x17/0x40
__pte_alloc+0x1e/0x110
alloc_set_pte+0x5fe/0xc20
do_fault+0x103/0x970
handle_mm_fault+0x61e/0xd10
__do_page_fault+0x252/0x4d0
do_page_fault+0x30/0x80
page_fault+0x28/0x30
task2:
__lock_page+0x86/0xa0
mpage_prepare_extent_to_map+0x2e7/0x310 [ext4]
ext4_writepages+0x479/0xd60
do_writepages+0x1e/0x30
__writeback_single_inode+0x45/0x320
writeback_sb_inodes+0x272/0x600
__writeback_inodes_wb+0x92/0xc0
wb_writeback+0x268/0x300
wb_workfn+0xb4/0x390
process_one_work+0x189/0x420
worker_thread+0x4e/0x4b0
kthread+0xe6/0x100
ret_from_fork+0x41/0x50
He adds
"task1 is waiting for the PageWriteback bit of the page that task2 has
collected in mpd->io_submit->io_bio, and tasks2 is waiting for the
LOCKED bit the page which tasks1 has locked"
More precisely task1 is handling a page fault and it has a page locked
while it charges a new page table to a memcg. That in turn hits a
memory limit reclaim and the memcg reclaim for legacy controller is
waiting on the writeback but that is never going to finish because the
writeback itself is waiting for the page locked in the #PF path. So
this is essentially ABBA deadlock:
lock_page(A)
SetPageWriteback(A)
unlock_page(A)
lock_page(B)
lock_page(B)
pte_alloc_pne
shrink_page_list
wait_on_page_writeback(A)
SetPageWriteback(B)
unlock_page(B)
# flush A, B to clear the writeback
This accumulating of more pages to flush is used by several filesystems
to generate a more optimal IO patterns.
Waiting for the writeback in legacy memcg controller is a workaround for
pre-mature OOM killer invocations because there is no dirty IO
throttling available for the controller. There is no easy way around
that unfortunately. Therefore fix this specific issue by pre-allocating
the page table outside of the page lock. We have that handy
infrastructure for that already so simply reuse the fault-around pattern
which already does this.
There are probably other hidden __GFP_ACCOUNT | GFP_KERNEL allocations
from under a fs page locked but they should be really rare. I am not
aware of a better solution unfortunately.
[akpm@linux-foundation.org: fix mm/memory.c:__do_fault()]
[akpm@linux-foundation.org: coding-style fixes]
[mhocko@kernel.org: enhance comment, per Johannes]
Link: http://lkml.kernel.org/r/20181214084948.GA5624@dhcp22.suse.cz
Link: http://lkml.kernel.org/r/20181213092221.27270-1-mhocko@kernel.org
Fixes: c3b94f44fcb0 ("memcg: further prevent OOM with too many dirty pages")
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reported-by: Liu Bo <bo.liu@linux.alibaba.com>
Debugged-by: Liu Bo <bo.liu@linux.alibaba.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Liu Bo <bo.liu@linux.alibaba.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
It is easy to trigger this with CONFIG_HARDENED_USERCOPY_PAGESPAN=y,
usercopy: Kernel memory overwrite attempt detected to spans multiple pages (offset 0, size 23)!
kernel BUG at mm/usercopy.c:102!
For example,
print_worker_info
char name[WQ_NAME_LEN] = { };
char desc[WORKER_DESC_LEN] = { };
probe_kernel_read(name, wq->name, sizeof(name) - 1);
probe_kernel_read(desc, worker->desc, sizeof(desc) - 1);
__copy_from_user_inatomic
check_object_size
check_heap_object
check_page_span
This is because on-stack variables could cross PAGE_SIZE boundary, and
failed this check,
if (likely(((unsigned long)ptr & (unsigned long)PAGE_MASK) ==
((unsigned long)end & (unsigned long)PAGE_MASK)))
ptr = FFFF889007D7EFF8
end = FFFF889007D7F00E
Hence, fix it by checking if it is a stack object first.
[keescook@chromium.org: improve comments after reorder]
Link: http://lkml.kernel.org/r/20190103165151.GA32845@beast
Link: http://lkml.kernel.org/r/20181231030254.99441-1-cai@lca.pw
Signed-off-by: Qian Cai <cai@lca.pw>
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
cache failed
Callers of __alloc_alien() check for NULL. We must do the same check in
__alloc_alien_cache to avoid NULL pointer dereferences on allocation
failures.
Link: http://lkml.kernel.org/r/010001680f42f192-82b4e12e-1565-4ee0-ae1f-1e98974906aa-000000@email.amazonses.com
Fixes: 49dfc304ba241 ("slab: use the lock on alien_cache, instead of the lock on array_cache")
Fixes: c8522a3a5832b ("Slab: introduce alloc_alien")
Signed-off-by: Christoph Lameter <cl@linux.com>
Reported-by: syzbot+d6ed4ec679652b4fd4e4@syzkaller.appspotmail.com
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Commit 5eed6f1dff87 ("fork,memcg: fix crash in free_thread_stack on
memcg charge fail") fixes a crash caused due to failed memcg charge of
the kernel stack. However the fix misses the cached_stacks case which
this patch fixes. So, the same crash can happen if the memcg charge of
a cached stack is failed.
Link: http://lkml.kernel.org/r/20190102180145.57406-1-shakeelb@google.com
Fixes: 5eed6f1dff87 ("fork,memcg: fix crash in free_thread_stack on memcg charge fail")
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Rik van Riel <riel@surriel.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
This patch includes some fixes and cleanup for idle-page writeback.
1. writeback_limit interface
Now writeback_limit interface is rather conusing. For example, once
writeback limit budget is exausted, admin can see 0 from
/sys/block/zramX/writeback_limit which is same semantic with disable
writeback_limit at this moment. IOW, admin cannot tell that zero came
from disable writeback limit or exausted writeback limit.
To make the interface clear, let's sepatate enable of writeback limit to
another knob - /sys/block/zram0/writeback_limit_enable
* before:
while true :
# to re-enable writeback limit once previous one is used up
echo 0 > /sys/block/zram0/writeback_limit
echo $((200<<20)) > /sys/block/zram0/writeback_limit
..
.. # used up the writeback limit budget
* new
# To enable writeback limit, from the beginning, admin should
# enable it.
echo $((200<<20)) > /sys/block/zram0/writeback_limit
echo 1 > /sys/block/zram/0/writeback_limit_enable
while true :
echo $((200<<20)) > /sys/block/zram0/writeback_limit
..
.. # used up the writeback limit budget
It's much strightforward.
2. fix condition check idle/huge writeback mode check
The mode in writeback_store is not bit opeartion any more so no need to
use bit operations. Furthermore, current condition check is broken in
that it does writeback every pages regardless of huge/idle.
3. clean up idle_store
No need to use goto.
[minchan@kernel.org: missed spin_lock_init]
Link: http://lkml.kernel.org/r/20190103001601.GA255139@google.com
Link: http://lkml.kernel.org/r/20181224033529.19450-1-minchan@kernel.org
Signed-off-by: Minchan Kim <minchan@kernel.org>
Suggested-by: John Dias <joaodias@google.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Cc: John Dias <joaodias@google.com>
Cc: Srinivas Paladugu <srnvs@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
fix typo after a recent commit causing headphones to have no sound
Fixes: ad43d528a7ac (ALSA: usb-audio: Define registers for CM6206)
Signed-off-by: Amadeusz Sławiński <amade@asmblr.net>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
|
|
This changes the fork(2) syscall to record the process start_time after
initializing the basic task structure but still before making the new
process visible to user-space.
Technically, we could record the start_time anytime during fork(2). But
this might lead to scenarios where a start_time is recorded long before
a process becomes visible to user-space. For instance, with
userfaultfd(2) and TLS, user-space can delay the execution of fork(2)
for an indefinite amount of time (and will, if this causes network
access, or similar).
By recording the start_time late, it much closer reflects the point in
time where the process becomes live and can be observed by other
processes.
Lastly, this makes it much harder for user-space to predict and control
the start_time they get assigned. Previously, user-space could fork a
process and stall it in copy_thread_tls() before its pid is allocated,
but after its start_time is recorded. This can be misused to later-on
cycle through PIDs and resume the stalled fork(2) yielding a process
that has the same pid and start_time as a process that existed before.
This can be used to circumvent security systems that identify processes
by their pid+start_time combination.
Even though user-space was always aware that start_time recording is
flaky (but several projects are known to still rely on start_time-based
identification), changing the start_time to be recorded late will help
mitigate existing attacks and make it much harder for user-space to
control the start_time a process gets assigned.
Reported-by: Jann Horn <jannh@google.com>
Signed-off-by: Tom Gundersen <teg@jklm.no>
Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
The below referenced commit adds a test for integer overflow, but in
doing so prevents the unmap ioctl from ever including the last page of
the address space. Subtract one to compare to the last address of the
unmap to avoid the overflow and wrap-around.
Fixes: 71a7d3d78e3c ("vfio/type1: silence integer overflow warning")
Link: https://bugzilla.redhat.com/show_bug.cgi?id=1662291
Cc: stable@vger.kernel.org # v4.15+
Reported-by: Pei Zhang <pezhang@redhat.com>
Debugged-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Tested-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
|
|
The handle_irq_perbit function loop every bit in hwirq local variable.
handle_irq_perbit(hwirq) {
for_everyt_bit_in(hwirq) {
handle_domain_irq()
->irq_exit()
->invoke_softirq()
->__do_softirq()
->local_irq_enable() // Here will cause new interrupt.
}
}
When new interrupt coming at local_irq_enable, it will finish another
interrupt handler and pull down the interrupt source. But hwirq is the
local variable for handle_irq_perbit(), it can't get new interrupt
controller pending reg status. So we need update hwirq with pending reg
in every loop.
Also change write_relax to writel could prevent stw from fast retire.
When local_irq is enabled, intc regs is really set-in.
Signed-off-by: Guo Ren <ren_guo@c-sky.com>
Cc: Lu Baoquan <lu.baoquan@intellif.com>
|
|
Commit: 4cf58924951e remove the address argument of pte_alloc without
modify csky related code. linux-5.0-rc1 compile failed with csky.
Remove the unnecessary address testing in pte_alloc().
Signed-off-by: Guo Ren <ren_guo@c-sky.com>
Cc: Joel Fernandes (Google) <joel@joelfernandes.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
|
|
drivers/vfio/pci/vfio_pci_nvlink2.c cannot be compiled for in-tree
building.
CC drivers/vfio/pci/vfio_pci_nvlink2.o
In file included from drivers/vfio/pci/trace.h:102,
from drivers/vfio/pci/vfio_pci_nvlink2.c:29:
./include/trace/define_trace.h:89:42: fatal error: ./trace.h: No such file or directory
#include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
^
compilation terminated.
make[1]: *** [scripts/Makefile.build;277: drivers/vfio/pci/vfio_pci_nvlink2.o] Error 1
To fix the build error, let's tell include/trace/define_trace.h the
location of drivers/vfio/pci/trace.h
Fixes: 7f92891778df ("vfio_pci: Add NVIDIA GV100GL [Tesla V100 SXM2] subdriver")
Reported-by: Laura Abbott <labbott@redhat.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
|
|
For I/O access, 810/807 store instruction fast retire will cause wrong
primitive. For example:
stw (clear interrupt source)
stw (unmask interrupt controller)
enable interrupt
stw is fast retire instruction. When PC is run at enable interrupt
stage, the clear interrupt source hasn't finished. It will cause another
wrong irq-enter.
So use mb() to prevent above.
Signed-off-by: Guo Ren <ren_guo@c-sky.com>
Cc: Lu Baoquan <lu.baoquan@intellif.com>
|
|
810 doesn't support jsri instruction and csky-as will leave
jsri + nop for relocation. Module-probe need replace them with
lrw + jsr.
Signed-off-by: Guo Ren <ren_guo@c-sky.com>
Cc: Hui Kai <huikai@acoinfo.com>
|
|
This patch fixes a memory corruption that occurred in the
qcom-nandc driver since it was converted to nand_scan().
On boot, an affected device will panic from a NPE at a weird place:
| Unable to handle kernel NULL pointer dereference at virtual address 0
| pgd = (ptrval)
| [00000000] *pgd=00000000
| Internal error: Oops: 80000005 [#1] SMP ARM
| CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.19.9 #0
| Hardware name: Generic DT based system
| PC is at (null)
| LR is at nand_block_isbad+0x90/0xa4
| pc : [<00000000>] lr : [<c0592240>] psr: 80000013
| sp : cf839d40 ip : 00000000 fp : cfae9e20
| r10: cf815810 r9 : 00000000 r8 : 00000000
| r7 : 00000000 r6 : 00000000 r5 : 00000001 r4 : cf815810
| r3 : 00000000 r2 : cfae9810 r1 : ffffffff r0 : cf815810
| Flags: Nzcv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none
| Control: 10c5387d Table: 8020406a DAC: 00000051
| Process swapper/0 (pid: 1, stack limit = 0x(ptrval))
| [<c0592240>] (nand_block_isbad) from [<c0580a94>]
| [<c0580a94>] (allocate_partition) from [<c05811e4>]
| [<c05811e4>] (add_mtd_partitions) from [<c0581164>]
| [<c0581164>] (parse_mtd_partitions) from [<c057def4>]
| [<c057def4>] (mtd_device_parse_register) from [<c059d274>]
| [<c059d274>] (qcom_nandc_probe) from [<c0567f00>]
The problem is that the nand_scan()'s qcom_nand_attach_chip callback
is updating the nandc->max_cwperpage from 1 to 4. This causes the
sg_init_table of clear_bam_transaction() in the driver's
qcom_nandc_block_bad() to memset much more than what was initially
allocated by alloc_bam_transaction().
This patch restores the old behavior by reallocating the shared bam
transaction alloc_bam_transaction() after the chip was identified,
but before mtd_device_parse_register() (which is an alias for
mtd_device_register() - see panic) gets called. This fixes the
corruption and the driver is working again.
Cc: stable@vger.kernel.org
Fixes: 6a3cec64f18c ("mtd: rawnand: qcom: convert driver to nand_scan()")
Signed-off-by: Christian Lamparter <chunkeey@gmail.com>
Acked-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Boris Brezillon <bbrezillon@kernel.org>
|
|
The "chip->dsp_spos_instance" can be NULL on some of the ealier error
paths in snd_cs46xx_create().
Reported-by: "Yavuz, Tuba" <tuba@ece.ufl.edu>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
|
|
core/ cBPF-JIT : TODO |
core/ eBPF-JIT : TODO |
core/ generic-idle-thread : ok |
core/ jump-labels : TODO |
core/ tracehook : ok |
debug/ KASAN : TODO |
debug/ gcov-profile-all : TODO |
debug/ kgdb : TODO |
debug/ kprobes-on-ftrace : TODO |
debug/ kprobes : TODO |
debug/ kretprobes : TODO |
debug/ optprobes : TODO |
debug/ stackprotector : TODO |
debug/ uprobes : TODO |
debug/ user-ret-profiler : TODO |
io/ dma-contiguous : ok |
locking/ cmpxchg-local : TODO |
locking/ lockdep : TODO |
locking/ queued-rwlocks : ok |
locking/ queued-spinlocks : TODO |
locking/ rwsem-optimized : TODO |
perf/ kprobes-event : TODO |
perf/ perf-regs : TODO |
perf/ perf-stackdump : TODO |
sched/ membarrier-sync-core : TODO |
sched/ numa-balancing : .. |
seccomp/ seccomp-filter : TODO |
time/ arch-tick-broadcast : TODO |
time/ clockevents : ok |
time/ context-tracking : TODO |
time/ irq-time-acct : TODO |
time/ modern-timekeeping : ok |
time/ virt-cpuacct : TODO |
vm/ ELF-ASLR : TODO |
vm/ PG_uncached : TODO |
vm/ THP : .. |
vm/ batch-unmap-tlb-flush: TODO |
vm/ huge-vmap : TODO |
vm/ ioremap_prot : TODO |
vm/ numa-memblock : .. |
vm/ pte_special : TODO |
Signed-off-by: Guo Ren <ren_guo@c-sky.com>
Cc: Arnd Bergmann <arnd@arndb.de>
|
|
add_mtd_device() can fail. We should always check its return value
and gracefully handle the failure case. Fix the call sites where this
not done (in mtdpart.c) and add a __must_check attribute to the
prototype to avoid this kind of mistakes.
Signed-off-by: Boris Brezillon <bbrezillon@kernel.org>
|
|
Commit 20167b70c894 ("nvmem: use EOPNOTSUPP instead of ENOSYS") changed
the nvmem_register() ret code from ENOSYS to EOPNOTSUPP when
CONFIG_NVMEM is not enabled, but the check in mtd_nvmem_add() was not
adjusted accordingly.
Cc: Bartosz Golaszewski <brgl@bgdev.pl>
Cc: Alban Bedel <albeu@free.fr>
Fixes: c4dfa25ab307 ("mtd: add support for reading MTD devices via the nvmem API")
Reported-by: kernel test robot <rong.a.chen@intel.com>
Signed-off-by: Boris Brezillon <bbrezillon@kernel.org>
Reviewed-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Boris Brezillon <bbrezillon@kernel.org>
|
|
Dell has new platform for ALC274.
This will support to enable headset mode.
Signed-off-by: Kailang Yang <kailang@realtek.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
|
|
In `create_composite_quirk`, the terminating condition of for loops is
`quirk->ifnum < 0`. So any composite quirks should end with `struct
snd_usb_audio_quirk` object with ifnum < 0.
for (quirk = quirk_comp->data; quirk->ifnum >= 0; ++quirk) {
.....
}
the data field of Bower's & Wilkins PX headphones usb device device quirks
do not end with {.ifnum = -1}, wihch may result in out-of-bound read.
This Patch fix the bug by adding an ending quirk object.
Fixes: 240a8af929c7 ("ALSA: usb-audio: Add a quirck for B&W PX headphones")
Signed-off-by: Hui Peng <benquike@163.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
|
|
There are a few places where we access the data without checking the
actual object size from the USB audio descriptor. This may result in
OOB access, as recently reported.
This patch addresses these missing checks. Most of added codes are
simple bLength checks in the caller side. For the input and output
terminal parsers, we put the length check in the parser functions.
For the input terminal, a new argument is added to distinguish between
UAC1 and the rest, as they treat different objects.
Reported-by: Mathias Payer <mathias.payer@nebelwelt.net>
Reported-by: Hui Peng <benquike@163.com>
Tested-by: Hui Peng <benquike@163.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
|
|
We've had some sanity checks of the mixer unit descriptors but they
are too loose and some corner cases are overlooked. Add more strict
checks in uac_mixer_unit_get_channels() for avoiding possible OOB
accesses by malformed descriptors.
This also changes the semantics of uac_mixer_unit_get_channels()
slightly. Now it returns zero for the cases where the descriptor
lacks of bmControls instead of -EINVAL. Then the caller side skips
the mixer creation for such unit while it keeps parsing it.
This corresponds to the case like Maya44.
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
|
|
The parser for the processing unit reads bNrInPins field before the
bLength sanity check, which may lead to an out-of-bound access when a
malformed descriptor is given. Fix it by assignment after the bLength
check.
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
|
|
For some reasons, I accidentally got rid of "generic-y += shmparam.h"
from some architectures.
Restore them to fix building c6x, h8300, hexagon, m68k, microblaze,
openrisc, and unicore32.
Fixes: d6e4b3e326d8 ("arch: remove redundant UAPI generic-y defines")
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull more Kbuild updates from Masahiro Yamada:
- improve boolinit.cocci and use_after_iter.cocci semantic patches
- fix alignment for kallsyms
- move 'asm goto' compiler test to Kconfig and clean up jump_label
CONFIG option
- generate asm-generic wrappers automatically if arch does not
implement mandatory UAPI headers
- remove redundant generic-y defines
- misc cleanups
* tag 'kbuild-v4.21-3' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
kconfig: rename generated .*conf-cfg to *conf-cfg
kbuild: remove unnecessary stubs for archheader and archscripts
kbuild: use assignment instead of define ... endef for filechk_* rules
arch: remove redundant UAPI generic-y defines
kbuild: generate asm-generic wrappers if mandatory headers are missing
arch: remove stale comments "UAPI Header export list"
riscv: remove redundant kernel-space generic-y
kbuild: change filechk to surround the given command with { }
kbuild: remove redundant target cleaning on failure
kbuild: clean up rule_dtc_dt_yaml
kbuild: remove UIMAGE_IN and UIMAGE_OUT
jump_label: move 'asm goto' support test to Kconfig
kallsyms: lower alignment on ARM
scripts: coccinelle: boolinit: drop warnings on named constants
scripts: coccinelle: check for redeclaration
kconfig: remove unused "file" field of yylval union
nds32: remove redundant kernel-space generic-y
nios2: remove unneeded HAS_DMA define
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf tooling updates form Ingo Molnar:
"A final batch of perf tooling changes: mostly fixes and small
improvements"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (29 commits)
perf session: Add comment for perf_session__register_idle_thread()
perf thread-stack: Fix thread stack processing for the idle task
perf thread-stack: Allocate an array of thread stacks
perf thread-stack: Factor out thread_stack__init()
perf thread-stack: Allow for a thread stack array
perf thread-stack: Avoid direct reference to the thread's stack
perf thread-stack: Tidy thread_stack__bottom() usage
perf thread-stack: Simplify some code in thread_stack__process()
tools gpio: Allow overriding CFLAGS
tools power turbostat: Override CFLAGS assignments and add LDFLAGS to build command
tools thermal tmon: Allow overriding CFLAGS assignments
tools power x86_energy_perf_policy: Override CFLAGS assignments and add LDFLAGS to build command
perf c2c: Increase the HITM ratio limit for displayed cachelines
perf c2c: Change the default coalesce setup
perf trace beauty ioctl: Beautify USBDEVFS_ commands
perf trace beauty: Export function to get the files for a thread
perf trace: Wire up ioctl's USBDEBFS_ cmd table generator
perf beauty ioctl: Add generator for USBDEVFS_ ioctl commands
tools headers uapi: Grab a copy of usbdevice_fs.h
perf trace: Store the major number for a file when storing its pathname
...
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The semantics of what "in core" means for the mincore() system call are
somewhat unclear, but Linux has always (since 2.3.52, which is when
mincore() was initially done) treated it as "page is available in page
cache" rather than "page is mapped in the mapping".
The problem with that traditional semantic is that it exposes a lot of
system cache state that it really probably shouldn't, and that users
shouldn't really even care about.
So let's try to avoid that information leak by simply changing the
semantics to be that mincore() counts actual mapped pages, not pages
that might be cheaply mapped if they were faulted (note the "might be"
part of the old semantics: being in the cache doesn't actually guarantee
that you can access them without IO anyway, since things like network
filesystems may have to revalidate the cache before use).
In many ways the old semantics were somewhat insane even aside from the
information leak issue. From the very beginning (and that beginning is
a long time ago: 2.3.52 was released in March 2000, I think), the code
had a comment saying
Later we can get more picky about what "in core" means precisely.
and this is that "later". Admittedly it is much later than is really
comfortable.
NOTE! This is a real semantic change, and it is for example known to
change the output of "fincore", since that program literally does a
mmmap without populating it, and then doing "mincore()" on that mapping
that doesn't actually have any pages in it.
I'm hoping that nobody actually has any workflow that cares, and the
info leak is real.
We may have to do something different if it turns out that people have
valid reasons to want the old semantics, and if we can limit the
information leak sanely.
Cc: Kevin Easton <kevin@guarana.org>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Masatake YAMATO <yamato@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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