- The 3 patch series "mm, swap: improve cluster scan strategy" from
Kairui Song improves performance and reduces the failure rate of swap
cluster allocation.
- The 4 patch series "support large align and nid in Rust allocators"
from Vitaly Wool permits Rust allocators to set NUMA node and large
alignment when perforning slub and vmalloc reallocs.
- The 2 patch series "mm/damon/vaddr: support stat-purpose DAMOS" from
Yueyang Pan extend DAMOS_STAT's handling of the DAMON operations sets
for virtual address spaces for ops-level DAMOS filters.
- The 3 patch series "execute PROCMAP_QUERY ioctl under per-vma lock"
from Suren Baghdasaryan reduces mmap_lock contention during reads of
/proc/pid/maps.
- The 2 patch series "mm/mincore: minor clean up for swap cache
checking" from Kairui Song performs some cleanup in the swap code.
- The 11 patch series "mm: vm_normal_page*() improvements" from David
Hildenbrand provides code cleanup in the pagemap code.
- The 5 patch series "add persistent huge zero folio support" from
Pankaj Raghav provides a block layer speedup by optionalls making the
huge_zero_pagepersistent, instead of releasing it when its refcount
falls to zero.
- The 3 patch series "kho: fixes and cleanups" from Mike Rapoport adds a
few touchups to the recently added Kexec Handover feature.
- The 10 patch series "mm: make mm->flags a bitmap and 64-bit on all
arches" from Lorenzo Stoakes turns mm_struct.flags into a bitmap. To
end the constant struggle with space shortage on 32-bit conflicting with
64-bit's needs.
- The 2 patch series "mm/swapfile.c and swap.h cleanup" from Chris Li
cleans up some swap code.
- The 7 patch series "selftests/mm: Fix false positives and skip
unsupported tests" from Donet Tom fixes a few things in our selftests
code.
- The 7 patch series "prctl: extend PR_SET_THP_DISABLE to only provide
THPs when advised" from David Hildenbrand "allows individual processes
to opt-out of THP=always into THP=madvise, without affecting other
workloads on the system".
It's a long story - the [1/N] changelog spells out the considerations.
- The 11 patch series "Add and use memdesc_flags_t" from Matthew Wilcox
gets us started on the memdesc project. Please see
https://kernelnewbies.org/MatthewWilcox/Memdescs and
https://blogs.oracle.com/linux/post/introducing-memdesc.
- The 3 patch series "Tiny optimization for large read operations" from
Chi Zhiling improves the efficiency of the pagecache read path.
- The 5 patch series "Better split_huge_page_test result check" from Zi
Yan improves our folio splitting selftest code.
- The 2 patch series "test that rmap behaves as expected" from Wei Yang
adds some rmap selftests.
- The 3 patch series "remove write_cache_pages()" from Christoph Hellwig
removes that function and converts its two remaining callers.
- The 2 patch series "selftests/mm: uffd-stress fixes" from Dev Jain
fixes some UFFD selftests issues.
- The 3 patch series "introduce kernel file mapped folios" from Boris
Burkov introduces the concept of "kernel file pages". Using these
permits btrfs to account its metadata pages to the root cgroup, rather
than to the cgroups of random inappropriate tasks.
- The 2 patch series "mm/pageblock: improve readability of some
pageblock handling" from Wei Yang provides some readability improvements
to the page allocator code.
- The 11 patch series "mm/damon: support ARM32 with LPAE" from SeongJae
Park teaches DAMON to understand arm32 highmem.
- The 4 patch series "tools: testing: Use existing atomic.h for
vma/maple tests" from Brendan Jackman performs some code cleanups and
deduplication under tools/testing/.
- The 2 patch series "maple_tree: Fix testing for 32bit compiles" from
Liam Howlett fixes a couple of 32-bit issues in
tools/testing/radix-tree.c.
- The 2 patch series "kasan: unify kasan_enabled() and remove
arch-specific implementations" from Sabyrzhan Tasbolatov moves KASAN
arch-specific initialization code into a common arch-neutral
implementation.
- The 3 patch series "mm: remove zpool" from Johannes Weiner removes
zspool - an indirection layer which now only redirects to a single thing
(zsmalloc).
- The 2 patch series "mm: task_stack: Stack handling cleanups" from
Pasha Tatashin makes a couple of cleanups in the fork code.
- The 37 patch series "mm: remove nth_page()" from David Hildenbrand
makes rather a lot of adjustments at various nth_page() callsites,
eventually permitting the removal of that undesirable helper function.
- The 2 patch series "introduce kasan.write_only option in hw-tags" from
Yeoreum Yun creates a KASAN read-only mode for ARM, using that
architecture's memory tagging feature. It is felt that a read-only mode
KASAN is suitable for use in production systems rather than debug-only.
- The 3 patch series "mm: hugetlb: cleanup hugetlb folio allocation"
from Kefeng Wang does some tidying in the hugetlb folio allocation code.
- The 12 patch series "mm: establish const-correctness for pointer
parameters" from Max Kellermann makes quite a number of the MM API
functions more accurate about the constness of their arguments. This
was getting in the way of subsystems (in this case CEPH) when they
attempt to improving their own const/non-const accuracy.
- The 7 patch series "Cleanup free_pages() misuse" from Vishal Moola
fixes a number of code sites which were confused over when to use
free_pages() vs __free_pages().
- The 3 patch series "Add Rust abstraction for Maple Trees" from Alice
Ryhl makes the mapletree code accessible to Rust. Required by nouveau
and by its forthcoming successor: the new Rust Nova driver.
- The 2 patch series "selftests/mm: split_huge_page_test:
split_pte_mapped_thp improvements" from David Hildenbrand adds a fix and
some cleanups to the thp selftesting code.
- The 14 patch series "mm, swap: introduce swap table as swap cache
(phase I)" from Chris Li and Kairui Song is the first step along the
path to implementing "swap tables" - a new approach to swap allocation
and state tracking which is expected to yield speed and space
improvements. This patchset itself yields a 5-20% performance benefit
in some situations.
- The 3 patch series "Some ptdesc cleanups" from Matthew Wilcox utilizes
the new memdesc layer to clean up the ptdesc code a little.
- The 3 patch series "Fix va_high_addr_switch.sh test failure" from
Chunyu Hu fixes some issues in our 5-level pagetable selftesting code.
- The 2 patch series "Minor fixes for memory allocation profiling" from
Suren Baghdasaryan addresses a couple of minor issues in relatively new
memory allocation profiling feature.
- The 3 patch series "Small cleanups" from Matthew Wilcox has a few
cleanups in preparation for more memdesc work.
- The 2 patch series "mm/damon: add addr_unit for DAMON_LRU_SORT and
DAMON_RECLAIM" from Quanmin Yan makes some changes to DAMON in
furtherance of supporting arm highmem.
- The 2 patch series "selftests/mm: Add -Wunreachable-code and fix
warnings" from Muhammad Anjum adds that compiler check to selftests code
and fixes the fallout, by removing dead code.
- The 10 patch series "Improvements to Victim Process Thawing and OOM
Reaper Traversal Order" from zhongjinji makes a number of improvements
in the OOM killer: mainly thawing a more appropriate group of victim
threads so they can release resources.
- The 5 patch series "mm/damon: misc fixups and improvements for 6.18"
from SeongJae Park is a bunch of small and unrelated fixups for DAMON.
- The 7 patch series "mm/damon: define and use DAMON initialization
check function" from SeongJae Park implement reliability and
maintainability improvements to a recently-added bug fix.
- The 2 patch series "mm/damon/stat: expose auto-tuned intervals and
non-idle ages" from SeongJae Park provides additional transparency to
userspace clients of the DAMON_STAT information.
- The 2 patch series "Expand scope of khugepaged anonymous collapse"
from Dev Jain removes some constraints on khubepaged's collapsing of
anon VMAs. It also increases the success rate of MADV_COLLAPSE against
an anon vma.
- The 2 patch series "mm: do not assume file == vma->vm_file in
compat_vma_mmap_prepare()" from Lorenzo Stoakes moves us further towards
removal of file_operations.mmap(). This patchset concentrates upon
clearing up the treatment of stacked filesystems.
- The 6 patch series "mm: Improve mlock tracking for large folios" from
Kiryl Shutsemau provides some fixes and improvements to mlock's tracking
of large folios. /proc/meminfo's "Mlocked" field became more accurate.
- The 2 patch series "mm/ksm: Fix incorrect accounting of KSM counters
during fork" from Donet Tom fixes several user-visible KSM stats
inaccuracies across forks and adds selftest code to verify these
counters.
- The 2 patch series "mm_slot: fix the usage of mm_slot_entry" from Wei
Yang addresses some potential but presently benign issues in KSM's
mm_slot handling.
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Merge tag 'mm-stable-2025-10-01-19-00' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:
- "mm, swap: improve cluster scan strategy" from Kairui Song improves
performance and reduces the failure rate of swap cluster allocation
- "support large align and nid in Rust allocators" from Vitaly Wool
permits Rust allocators to set NUMA node and large alignment when
perforning slub and vmalloc reallocs
- "mm/damon/vaddr: support stat-purpose DAMOS" from Yueyang Pan extend
DAMOS_STAT's handling of the DAMON operations sets for virtual
address spaces for ops-level DAMOS filters
- "execute PROCMAP_QUERY ioctl under per-vma lock" from Suren
Baghdasaryan reduces mmap_lock contention during reads of
/proc/pid/maps
- "mm/mincore: minor clean up for swap cache checking" from Kairui Song
performs some cleanup in the swap code
- "mm: vm_normal_page*() improvements" from David Hildenbrand provides
code cleanup in the pagemap code
- "add persistent huge zero folio support" from Pankaj Raghav provides
a block layer speedup by optionalls making the
huge_zero_pagepersistent, instead of releasing it when its refcount
falls to zero
- "kho: fixes and cleanups" from Mike Rapoport adds a few touchups to
the recently added Kexec Handover feature
- "mm: make mm->flags a bitmap and 64-bit on all arches" from Lorenzo
Stoakes turns mm_struct.flags into a bitmap. To end the constant
struggle with space shortage on 32-bit conflicting with 64-bit's
needs
- "mm/swapfile.c and swap.h cleanup" from Chris Li cleans up some swap
code
- "selftests/mm: Fix false positives and skip unsupported tests" from
Donet Tom fixes a few things in our selftests code
- "prctl: extend PR_SET_THP_DISABLE to only provide THPs when advised"
from David Hildenbrand "allows individual processes to opt-out of
THP=always into THP=madvise, without affecting other workloads on the
system".
It's a long story - the [1/N] changelog spells out the considerations
- "Add and use memdesc_flags_t" from Matthew Wilcox gets us started on
the memdesc project. Please see
https://kernelnewbies.org/MatthewWilcox/Memdescs and
https://blogs.oracle.com/linux/post/introducing-memdesc
- "Tiny optimization for large read operations" from Chi Zhiling
improves the efficiency of the pagecache read path
- "Better split_huge_page_test result check" from Zi Yan improves our
folio splitting selftest code
- "test that rmap behaves as expected" from Wei Yang adds some rmap
selftests
- "remove write_cache_pages()" from Christoph Hellwig removes that
function and converts its two remaining callers
- "selftests/mm: uffd-stress fixes" from Dev Jain fixes some UFFD
selftests issues
- "introduce kernel file mapped folios" from Boris Burkov introduces
the concept of "kernel file pages". Using these permits btrfs to
account its metadata pages to the root cgroup, rather than to the
cgroups of random inappropriate tasks
- "mm/pageblock: improve readability of some pageblock handling" from
Wei Yang provides some readability improvements to the page allocator
code
- "mm/damon: support ARM32 with LPAE" from SeongJae Park teaches DAMON
to understand arm32 highmem
- "tools: testing: Use existing atomic.h for vma/maple tests" from
Brendan Jackman performs some code cleanups and deduplication under
tools/testing/
- "maple_tree: Fix testing for 32bit compiles" from Liam Howlett fixes
a couple of 32-bit issues in tools/testing/radix-tree.c
- "kasan: unify kasan_enabled() and remove arch-specific
implementations" from Sabyrzhan Tasbolatov moves KASAN arch-specific
initialization code into a common arch-neutral implementation
- "mm: remove zpool" from Johannes Weiner removes zspool - an
indirection layer which now only redirects to a single thing
(zsmalloc)
- "mm: task_stack: Stack handling cleanups" from Pasha Tatashin makes a
couple of cleanups in the fork code
- "mm: remove nth_page()" from David Hildenbrand makes rather a lot of
adjustments at various nth_page() callsites, eventually permitting
the removal of that undesirable helper function
- "introduce kasan.write_only option in hw-tags" from Yeoreum Yun
creates a KASAN read-only mode for ARM, using that architecture's
memory tagging feature. It is felt that a read-only mode KASAN is
suitable for use in production systems rather than debug-only
- "mm: hugetlb: cleanup hugetlb folio allocation" from Kefeng Wang does
some tidying in the hugetlb folio allocation code
- "mm: establish const-correctness for pointer parameters" from Max
Kellermann makes quite a number of the MM API functions more accurate
about the constness of their arguments. This was getting in the way
of subsystems (in this case CEPH) when they attempt to improving
their own const/non-const accuracy
- "Cleanup free_pages() misuse" from Vishal Moola fixes a number of
code sites which were confused over when to use free_pages() vs
__free_pages()
- "Add Rust abstraction for Maple Trees" from Alice Ryhl makes the
mapletree code accessible to Rust. Required by nouveau and by its
forthcoming successor: the new Rust Nova driver
- "selftests/mm: split_huge_page_test: split_pte_mapped_thp
improvements" from David Hildenbrand adds a fix and some cleanups to
the thp selftesting code
- "mm, swap: introduce swap table as swap cache (phase I)" from Chris
Li and Kairui Song is the first step along the path to implementing
"swap tables" - a new approach to swap allocation and state tracking
which is expected to yield speed and space improvements. This
patchset itself yields a 5-20% performance benefit in some situations
- "Some ptdesc cleanups" from Matthew Wilcox utilizes the new memdesc
layer to clean up the ptdesc code a little
- "Fix va_high_addr_switch.sh test failure" from Chunyu Hu fixes some
issues in our 5-level pagetable selftesting code
- "Minor fixes for memory allocation profiling" from Suren Baghdasaryan
addresses a couple of minor issues in relatively new memory
allocation profiling feature
- "Small cleanups" from Matthew Wilcox has a few cleanups in
preparation for more memdesc work
- "mm/damon: add addr_unit for DAMON_LRU_SORT and DAMON_RECLAIM" from
Quanmin Yan makes some changes to DAMON in furtherance of supporting
arm highmem
- "selftests/mm: Add -Wunreachable-code and fix warnings" from Muhammad
Anjum adds that compiler check to selftests code and fixes the
fallout, by removing dead code
- "Improvements to Victim Process Thawing and OOM Reaper Traversal
Order" from zhongjinji makes a number of improvements in the OOM
killer: mainly thawing a more appropriate group of victim threads so
they can release resources
- "mm/damon: misc fixups and improvements for 6.18" from SeongJae Park
is a bunch of small and unrelated fixups for DAMON
- "mm/damon: define and use DAMON initialization check function" from
SeongJae Park implement reliability and maintainability improvements
to a recently-added bug fix
- "mm/damon/stat: expose auto-tuned intervals and non-idle ages" from
SeongJae Park provides additional transparency to userspace clients
of the DAMON_STAT information
- "Expand scope of khugepaged anonymous collapse" from Dev Jain removes
some constraints on khubepaged's collapsing of anon VMAs. It also
increases the success rate of MADV_COLLAPSE against an anon vma
- "mm: do not assume file == vma->vm_file in compat_vma_mmap_prepare()"
from Lorenzo Stoakes moves us further towards removal of
file_operations.mmap(). This patchset concentrates upon clearing up
the treatment of stacked filesystems
- "mm: Improve mlock tracking for large folios" from Kiryl Shutsemau
provides some fixes and improvements to mlock's tracking of large
folios. /proc/meminfo's "Mlocked" field became more accurate
- "mm/ksm: Fix incorrect accounting of KSM counters during fork" from
Donet Tom fixes several user-visible KSM stats inaccuracies across
forks and adds selftest code to verify these counters
- "mm_slot: fix the usage of mm_slot_entry" from Wei Yang addresses
some potential but presently benign issues in KSM's mm_slot handling
* tag 'mm-stable-2025-10-01-19-00' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (372 commits)
mm: swap: check for stable address space before operating on the VMA
mm: convert folio_page() back to a macro
mm/khugepaged: use start_addr/addr for improved readability
hugetlbfs: skip VMAs without shareable locks in hugetlb_vmdelete_list
alloc_tag: fix boot failure due to NULL pointer dereference
mm: silence data-race in update_hiwater_rss
mm/memory-failure: don't select MEMORY_ISOLATION
mm/khugepaged: remove definition of struct khugepaged_mm_slot
mm/ksm: get mm_slot by mm_slot_entry() when slot is !NULL
hugetlb: increase number of reserving hugepages via cmdline
selftests/mm: add fork inheritance test for ksm_merging_pages counter
mm/ksm: fix incorrect KSM counter handling in mm_struct during fork
drivers/base/node: fix double free in register_one_node()
mm: remove PMD alignment constraint in execmem_vmalloc()
mm/memory_hotplug: fix typo 'esecially' -> 'especially'
mm/rmap: improve mlock tracking for large folios
mm/filemap: map entire large folio faultaround
mm/fault: try to map the entire file folio in finish_fault()
mm/rmap: mlock large folios in try_to_unmap_one()
mm/rmap: fix a mlock race condition in folio_referenced_one()
...
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Merge tag 'slab-for-6.18' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab
Pull slab updates from Vlastimil Babka:
- A new layer for caching objects for allocation and free via percpu
arrays called sheaves.
The aim is to combine the good parts of SLAB (lower-overhead and
simpler percpu caching, compared to SLUB) without the past issues
with arrays for freeing remote NUMA node objects and their flushing.
It also allows more efficient kfree_rcu(), and cheaper object
preallocations for cases where the exact number of objects is
unknown, but an upper bound is.
Currently VMAs and maple nodes are using this new caching, with a
plan to enable it for all caches and remove the complex SLUB fastpath
based on cpu (partial) slabs and this_cpu_cmpxchg_double().
(Vlastimil Babka, with Liam Howlett and Pedro Falcato for the maple
tree changes)
- Re-entrant kmalloc_nolock(), which allows opportunistic allocations
from NMI and tracing/kprobe contexts.
Building on prior page allocator and memcg changes, it will result in
removing BPF-specific caches on top of slab (Alexei Starovoitov)
- Various fixes and cleanups. (Kuan-Wei Chiu, Matthew Wilcox, Suren
Baghdasaryan, Ye Liu)
* tag 'slab-for-6.18' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab: (40 commits)
slab: Introduce kmalloc_nolock() and kfree_nolock().
slab: Reuse first bit for OBJEXTS_ALLOC_FAIL
slab: Make slub local_(try)lock more precise for LOCKDEP
mm: Introduce alloc_frozen_pages_nolock()
mm: Allow GFP_ACCOUNT to be used in alloc_pages_nolock().
locking/local_lock: Introduce local_lock_is_locked().
maple_tree: Convert forking to use the sheaf interface
maple_tree: Add single node allocation support to maple state
maple_tree: Prefilled sheaf conversion and testing
tools/testing: Add support for prefilled slab sheafs
maple_tree: Replace mt_free_one() with kfree()
maple_tree: Use kfree_rcu in ma_free_rcu
testing/radix-tree/maple: Hack around kfree_rcu not existing
tools/testing: include maple-shim.c in maple.c
maple_tree: use percpu sheaves for maple_node_cache
mm, vma: use percpu sheaves for vm_area_struct cache
tools/testing: Add support for changes to slab for sheaves
slab: allow NUMA restricted allocations to use percpu sheaves
tools/testing/vma: Implement vm_refcnt reset
slab: skip percpu sheaves for remote object freeing
...
kmalloc_nolock() relies on ability of local_trylock_t to detect
the situation when per-cpu kmem_cache is locked.
In !PREEMPT_RT local_(try)lock_irqsave(&s->cpu_slab->lock, flags)
disables IRQs and marks s->cpu_slab->lock as acquired.
local_lock_is_locked(&s->cpu_slab->lock) returns true when
slab is in the middle of manipulating per-cpu cache
of that specific kmem_cache.
kmalloc_nolock() can be called from any context and can re-enter
into ___slab_alloc():
kmalloc() -> ___slab_alloc(cache_A) -> irqsave -> NMI -> bpf ->
kmalloc_nolock() -> ___slab_alloc(cache_B)
or
kmalloc() -> ___slab_alloc(cache_A) -> irqsave -> tracepoint/kprobe -> bpf ->
kmalloc_nolock() -> ___slab_alloc(cache_B)
Hence the caller of ___slab_alloc() checks if &s->cpu_slab->lock
can be acquired without a deadlock before invoking the function.
If that specific per-cpu kmem_cache is busy the kmalloc_nolock()
retries in a different kmalloc bucket. The second attempt will
likely succeed, since this cpu locked different kmem_cache.
Similarly, in PREEMPT_RT local_lock_is_locked() returns true when
per-cpu rt_spin_lock is locked by current _task_. In this case
re-entrance into the same kmalloc bucket is unsafe, and
kmalloc_nolock() tries a different bucket that is most likely is
not locked by the current task. Though it may be locked by a
different task it's safe to rt_spin_lock() and sleep on it.
Similar to alloc_pages_nolock() the kmalloc_nolock() returns NULL
immediately if called from hard irq or NMI in PREEMPT_RT.
kfree_nolock() defers freeing to irq_work when local_lock_is_locked()
and (in_nmi() or in PREEMPT_RT).
SLUB_TINY config doesn't use local_lock_is_locked() and relies on
spin_trylock_irqsave(&n->list_lock) to allocate,
while kfree_nolock() always defers to irq_work.
Note, kfree_nolock() must be called _only_ for objects allocated
with kmalloc_nolock(). Debug checks (like kmemleak and kfence)
were skipped on allocation, hence obj = kmalloc(); kfree_nolock(obj);
will miss kmemleak/kfence book keeping and will cause false positives.
large_kmalloc is not supported by either kmalloc_nolock()
or kfree_nolock().
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Harry Yoo <harry.yoo@oracle.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Patch series "kasan: unify kasan_enabled() and remove arch-specific
implementations", v6.
This patch series addresses the fragmentation in KASAN initialization
across architectures by introducing a unified approach that eliminates
duplicate static keys and arch-specific kasan_arch_is_ready()
implementations.
The core issue is that different architectures have inconsistent approaches
to KASAN readiness tracking:
- PowerPC, LoongArch, and UML arch, each implement own kasan_arch_is_ready()
- Only HW_TAGS mode had a unified static key (kasan_flag_enabled)
- Generic and SW_TAGS modes relied on arch-specific solutions
or always-on behavior
This patch (of 2):
Introduce CONFIG_ARCH_DEFER_KASAN to identify architectures [1] that need
to defer KASAN initialization until shadow memory is properly set up, and
unify the static key infrastructure across all KASAN modes.
[1] PowerPC, UML, LoongArch selects ARCH_DEFER_KASAN.
The core issue is that different architectures haveinconsistent approaches
to KASAN readiness tracking:
- PowerPC, LoongArch, and UML arch, each implement own
kasan_arch_is_ready()
- Only HW_TAGS mode had a unified static key (kasan_flag_enabled)
- Generic and SW_TAGS modes relied on arch-specific solutions or always-on
behavior
This patch addresses the fragmentation in KASAN initialization across
architectures by introducing a unified approach that eliminates duplicate
static keys and arch-specific kasan_arch_is_ready() implementations.
Let's replace kasan_arch_is_ready() with existing kasan_enabled() check,
which examines the static key being enabled if arch selects
ARCH_DEFER_KASAN or has HW_TAGS mode support. For other arch,
kasan_enabled() checks the enablement during compile time.
Now KASAN users can use a single kasan_enabled() check everywhere.
Link: https://lkml.kernel.org/r/20250810125746.1105476-1-snovitoll@gmail.com
Link: https://lkml.kernel.org/r/20250810125746.1105476-2-snovitoll@gmail.com
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217049
Signed-off-by: Sabyrzhan Tasbolatov <snovitoll@gmail.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com> #powerpc
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Alexandre Ghiti <alex@ghiti.fr>
Cc: Alexandre Ghiti <alexghiti@rivosinc.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: David Gow <davidgow@google.com>
Cc: Dmitriy Vyukov <dvyukov@google.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Huacai Chen <chenhuacai@loongson.cn>
Cc: Marco Elver <elver@google.com>
Cc: Qing Zhang <zhangqing@loongson.cn>
Cc: Sabyrzhan Tasbolatov <snovitoll@gmail.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
kasan_populate_vmalloc() and its helpers ignore the caller's gfp_mask and
always allocate memory using the hardcoded GFP_KERNEL flag. This makes
them inconsistent with vmalloc(), which was recently extended to support
GFP_NOFS and GFP_NOIO allocations.
Page table allocations performed during shadow population also ignore the
external gfp_mask. To preserve the intended semantics of GFP_NOFS and
GFP_NOIO, wrap the apply_to_page_range() calls into the appropriate
memalloc scope.
xfs calls vmalloc with GFP_NOFS, so this bug could lead to deadlock.
There was a report here
https://lkml.kernel.org/r/686ea951.050a0220.385921.0016.GAE@google.com
This patch:
- Extends kasan_populate_vmalloc() and helpers to take gfp_mask;
- Passes gfp_mask down to alloc_pages_bulk() and __get_free_page();
- Enforces GFP_NOFS/NOIO semantics with memalloc_*_save()/restore()
around apply_to_page_range();
- Updates vmalloc.c and percpu allocator call sites accordingly.
Link: https://lkml.kernel.org/r/20250831121058.92971-1-urezki@gmail.com
Fixes: 451769ebb7 ("mm/vmalloc: alloc GFP_NO{FS,IO} for vmalloc")
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Reported-by: syzbot+3470c9ffee63e4abafeb@syzkaller.appspotmail.com
Reviewed-by: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
indivudual patches which are described in their changelogs.
- "Allocate and free frozen pages" from Matthew Wilcox reorganizes the
page allocator so we end up with the ability to allocate and free
zero-refcount pages. So that callers (ie, slab) can avoid a refcount
inc & dec.
- "Support large folios for tmpfs" from Baolin Wang teaches tmpfs to use
large folios other than PMD-sized ones.
- "Fix mm/rodata_test" from Petr Tesarik performs some maintenance and
fixes for this small built-in kernel selftest.
- "mas_anode_descend() related cleanup" from Wei Yang tidies up part of
the mapletree code.
- "mm: fix format issues and param types" from Keren Sun implements a
few minor code cleanups.
- "simplify split calculation" from Wei Yang provides a few fixes and a
test for the mapletree code.
- "mm/vma: make more mmap logic userland testable" from Lorenzo Stoakes
continues the work of moving vma-related code into the (relatively) new
mm/vma.c.
- "mm/page_alloc: gfp flags cleanups for alloc_contig_*()" from David
Hildenbrand cleans up and rationalizes handling of gfp flags in the page
allocator.
- "readahead: Reintroduce fix for improper RA window sizing" from Jan
Kara is a second attempt at fixing a readahead window sizing issue. It
should reduce the amount of unnecessary reading.
- "synchronously scan and reclaim empty user PTE pages" from Qi Zheng
addresses an issue where "huge" amounts of pte pagetables are
accumulated
(https://lore.kernel.org/lkml/cover.1718267194.git.zhengqi.arch@bytedance.com/).
Qi's series addresses this windup by synchronously freeing PTE memory
within the context of madvise(MADV_DONTNEED).
- "selftest/mm: Remove warnings found by adding compiler flags" from
Muhammad Usama Anjum fixes some build warnings in the selftests code
when optional compiler warnings are enabled.
- "mm: don't use __GFP_HARDWALL when migrating remote pages" from David
Hildenbrand tightens the allocator's observance of __GFP_HARDWALL.
- "pkeys kselftests improvements" from Kevin Brodsky implements various
fixes and cleanups in the MM selftests code, mainly pertaining to the
pkeys tests.
- "mm/damon: add sample modules" from SeongJae Park enhances DAMON to
estimate application working set size.
- "memcg/hugetlb: Rework memcg hugetlb charging" from Joshua Hahn
provides some cleanups to memcg's hugetlb charging logic.
- "mm/swap_cgroup: remove global swap cgroup lock" from Kairui Song
removes the global swap cgroup lock. A speedup of 10% for a tmpfs-based
kernel build was demonstrated.
- "zram: split page type read/write handling" from Sergey Senozhatsky
has several fixes and cleaups for zram in the area of zram_write_page().
A watchdog softlockup warning was eliminated.
- "move pagetable_*_dtor() to __tlb_remove_table()" from Kevin Brodsky
cleans up the pagetable destructor implementations. A rare
use-after-free race is fixed.
- "mm/debug: introduce and use VM_WARN_ON_VMG()" from Lorenzo Stoakes
simplifies and cleans up the debugging code in the VMA merging logic.
- "Account page tables at all levels" from Kevin Brodsky cleans up and
regularizes the pagetable ctor/dtor handling. This results in
improvements in accounting accuracy.
- "mm/damon: replace most damon_callback usages in sysfs with new core
functions" from SeongJae Park cleans up and generalizes DAMON's sysfs
file interface logic.
- "mm/damon: enable page level properties based monitoring" from
SeongJae Park increases the amount of information which is presented in
response to DAMOS actions.
- "mm/damon: remove DAMON debugfs interface" from SeongJae Park removes
DAMON's long-deprecated debugfs interfaces. Thus the migration to sysfs
is completed.
- "mm/hugetlb: Refactor hugetlb allocation resv accounting" from Peter
Xu cleans up and generalizes the hugetlb reservation accounting.
- "mm: alloc_pages_bulk: small API refactor" from Luiz Capitulino
removes a never-used feature of the alloc_pages_bulk() interface.
- "mm/damon: extend DAMOS filters for inclusion" from SeongJae Park
extends DAMOS filters to support not only exclusion (rejecting), but
also inclusion (allowing) behavior.
- "Add zpdesc memory descriptor for zswap.zpool" from Alex Shi
"introduces a new memory descriptor for zswap.zpool that currently
overlaps with struct page for now. This is part of the effort to reduce
the size of struct page and to enable dynamic allocation of memory
descriptors."
- "mm, swap: rework of swap allocator locks" from Kairui Song redoes and
simplifies the swap allocator locking. A speedup of 400% was
demonstrated for one workload. As was a 35% reduction for kernel build
time with swap-on-zram.
- "mm: update mips to use do_mmap(), make mmap_region() internal" from
Lorenzo Stoakes reworks MIPS's use of mmap_region() so that
mmap_region() can be made MM-internal.
- "mm/mglru: performance optimizations" from Yu Zhao fixes a few MGLRU
regressions and otherwise improves MGLRU performance.
- "Docs/mm/damon: add tuning guide and misc updates" from SeongJae Park
updates DAMON documentation.
- "Cleanup for memfd_create()" from Isaac Manjarres does that thing.
- "mm: hugetlb+THP folio and migration cleanups" from David Hildenbrand
provides various cleanups in the areas of hugetlb folios, THP folios and
migration.
- "Uncached buffered IO" from Jens Axboe implements the new
RWF_DONTCACHE flag which provides synchronous dropbehind for pagecache
reading and writing. To permite userspace to address issues with
massive buildup of useless pagecache when reading/writing fast devices.
- "selftests/mm: virtual_address_range: Reduce memory" from Thomas
Weißschuh fixes and optimizes some of the MM selftests.
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Merge tag 'mm-stable-2025-01-26-14-59' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:
"The various patchsets are summarized below. Plus of course many
indivudual patches which are described in their changelogs.
- "Allocate and free frozen pages" from Matthew Wilcox reorganizes
the page allocator so we end up with the ability to allocate and
free zero-refcount pages. So that callers (ie, slab) can avoid a
refcount inc & dec
- "Support large folios for tmpfs" from Baolin Wang teaches tmpfs to
use large folios other than PMD-sized ones
- "Fix mm/rodata_test" from Petr Tesarik performs some maintenance
and fixes for this small built-in kernel selftest
- "mas_anode_descend() related cleanup" from Wei Yang tidies up part
of the mapletree code
- "mm: fix format issues and param types" from Keren Sun implements a
few minor code cleanups
- "simplify split calculation" from Wei Yang provides a few fixes and
a test for the mapletree code
- "mm/vma: make more mmap logic userland testable" from Lorenzo
Stoakes continues the work of moving vma-related code into the
(relatively) new mm/vma.c
- "mm/page_alloc: gfp flags cleanups for alloc_contig_*()" from David
Hildenbrand cleans up and rationalizes handling of gfp flags in the
page allocator
- "readahead: Reintroduce fix for improper RA window sizing" from Jan
Kara is a second attempt at fixing a readahead window sizing issue.
It should reduce the amount of unnecessary reading
- "synchronously scan and reclaim empty user PTE pages" from Qi Zheng
addresses an issue where "huge" amounts of pte pagetables are
accumulated:
https://lore.kernel.org/lkml/cover.1718267194.git.zhengqi.arch@bytedance.com/
Qi's series addresses this windup by synchronously freeing PTE
memory within the context of madvise(MADV_DONTNEED)
- "selftest/mm: Remove warnings found by adding compiler flags" from
Muhammad Usama Anjum fixes some build warnings in the selftests
code when optional compiler warnings are enabled
- "mm: don't use __GFP_HARDWALL when migrating remote pages" from
David Hildenbrand tightens the allocator's observance of
__GFP_HARDWALL
- "pkeys kselftests improvements" from Kevin Brodsky implements
various fixes and cleanups in the MM selftests code, mainly
pertaining to the pkeys tests
- "mm/damon: add sample modules" from SeongJae Park enhances DAMON to
estimate application working set size
- "memcg/hugetlb: Rework memcg hugetlb charging" from Joshua Hahn
provides some cleanups to memcg's hugetlb charging logic
- "mm/swap_cgroup: remove global swap cgroup lock" from Kairui Song
removes the global swap cgroup lock. A speedup of 10% for a
tmpfs-based kernel build was demonstrated
- "zram: split page type read/write handling" from Sergey Senozhatsky
has several fixes and cleaups for zram in the area of
zram_write_page(). A watchdog softlockup warning was eliminated
- "move pagetable_*_dtor() to __tlb_remove_table()" from Kevin
Brodsky cleans up the pagetable destructor implementations. A rare
use-after-free race is fixed
- "mm/debug: introduce and use VM_WARN_ON_VMG()" from Lorenzo Stoakes
simplifies and cleans up the debugging code in the VMA merging
logic
- "Account page tables at all levels" from Kevin Brodsky cleans up
and regularizes the pagetable ctor/dtor handling. This results in
improvements in accounting accuracy
- "mm/damon: replace most damon_callback usages in sysfs with new
core functions" from SeongJae Park cleans up and generalizes
DAMON's sysfs file interface logic
- "mm/damon: enable page level properties based monitoring" from
SeongJae Park increases the amount of information which is
presented in response to DAMOS actions
- "mm/damon: remove DAMON debugfs interface" from SeongJae Park
removes DAMON's long-deprecated debugfs interfaces. Thus the
migration to sysfs is completed
- "mm/hugetlb: Refactor hugetlb allocation resv accounting" from
Peter Xu cleans up and generalizes the hugetlb reservation
accounting
- "mm: alloc_pages_bulk: small API refactor" from Luiz Capitulino
removes a never-used feature of the alloc_pages_bulk() interface
- "mm/damon: extend DAMOS filters for inclusion" from SeongJae Park
extends DAMOS filters to support not only exclusion (rejecting),
but also inclusion (allowing) behavior
- "Add zpdesc memory descriptor for zswap.zpool" from Alex Shi
introduces a new memory descriptor for zswap.zpool that currently
overlaps with struct page for now. This is part of the effort to
reduce the size of struct page and to enable dynamic allocation of
memory descriptors
- "mm, swap: rework of swap allocator locks" from Kairui Song redoes
and simplifies the swap allocator locking. A speedup of 400% was
demonstrated for one workload. As was a 35% reduction for kernel
build time with swap-on-zram
- "mm: update mips to use do_mmap(), make mmap_region() internal"
from Lorenzo Stoakes reworks MIPS's use of mmap_region() so that
mmap_region() can be made MM-internal
- "mm/mglru: performance optimizations" from Yu Zhao fixes a few
MGLRU regressions and otherwise improves MGLRU performance
- "Docs/mm/damon: add tuning guide and misc updates" from SeongJae
Park updates DAMON documentation
- "Cleanup for memfd_create()" from Isaac Manjarres does that thing
- "mm: hugetlb+THP folio and migration cleanups" from David
Hildenbrand provides various cleanups in the areas of hugetlb
folios, THP folios and migration
- "Uncached buffered IO" from Jens Axboe implements the new
RWF_DONTCACHE flag which provides synchronous dropbehind for
pagecache reading and writing. To permite userspace to address
issues with massive buildup of useless pagecache when
reading/writing fast devices
- "selftests/mm: virtual_address_range: Reduce memory" from Thomas
Weißschuh fixes and optimizes some of the MM selftests"
* tag 'mm-stable-2025-01-26-14-59' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (321 commits)
mm/compaction: fix UBSAN shift-out-of-bounds warning
s390/mm: add missing ctor/dtor on page table upgrade
kasan: sw_tags: use str_on_off() helper in kasan_init_sw_tags()
tools: add VM_WARN_ON_VMG definition
mm/damon/core: use str_high_low() helper in damos_wmark_wait_us()
seqlock: add missing parameter documentation for raw_seqcount_try_begin()
mm/page-writeback: consolidate wb_thresh bumping logic into __wb_calc_thresh
mm/page_alloc: remove the incorrect and misleading comment
zram: remove zcomp_stream_put() from write_incompressible_page()
mm: separate move/undo parts from migrate_pages_batch()
mm/kfence: use str_write_read() helper in get_access_type()
selftests/mm/mkdirty: fix memory leak in test_uffdio_copy()
kasan: hw_tags: Use str_on_off() helper in kasan_init_hw_tags()
selftests/mm: virtual_address_range: avoid reading from VM_IO mappings
selftests/mm: vm_util: split up /proc/self/smaps parsing
selftests/mm: virtual_address_range: unmap chunks after validation
selftests/mm: virtual_address_range: mmap() without PROT_WRITE
selftests/memfd/memfd_test: fix possible NULL pointer dereference
mm: add FGP_DONTCACHE folio creation flag
mm: call filemap_fdatawrite_range_kick() after IOCB_DONTCACHE issue
...
kasan_record_aux_stack_noalloc() was introduced to record a stack trace
without allocating memory in the process. It has been added to callers
which were invoked while a raw_spinlock_t was held. More and more callers
were identified and changed over time. Is it a good thing to have this
while functions try their best to do a locklessly setup? The only
downside of having kasan_record_aux_stack() not allocate any memory is
that we end up without a stacktrace if stackdepot runs out of memory and
at the same stacktrace was not recorded before To quote Marco Elver from
https://lore.kernel.org/all/CANpmjNPmQYJ7pv1N3cuU8cP18u7PP_uoZD8YxwZd4jtbof9nVQ@mail.gmail.com/
| I'd be in favor, it simplifies things. And stack depot should be
| able to replenish its pool sufficiently in the "non-aux" cases
| i.e. regular allocations. Worst case we fail to record some
| aux stacks, but I think that's only really bad if there's a bug
| around one of these allocations. In general the probabilities
| of this being a regression are extremely small [...]
Make the kasan_record_aux_stack_noalloc() behaviour default as
kasan_record_aux_stack().
[bigeasy@linutronix.de: dressed the diff as patch]
Link: https://lkml.kernel.org/r/20241122155451.Mb2pmeyJ@linutronix.de
Fixes: 7cb3007ce2 ("kasan: generic: introduce kasan_record_aux_stack_noalloc()")
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reported-by: syzbot+39f85d612b7c20d8db48@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/67275485.050a0220.3c8d68.0a37.GAE@google.com
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Reviewed-by: Marco Elver <elver@google.com>
Reviewed-by: Waiman Long <longman@redhat.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Ben Segall <bsegall@google.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Frederic Weisbecker <frederic@kernel.org>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Joel Fernandes (Google) <joel@joelfernandes.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: <kasan-dev@googlegroups.com>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Liam R. Howlett <Liam.Howlett@Oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Neeraj Upadhyay <neeraj.upadhyay@kernel.org>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: syzkaller-bugs@googlegroups.com
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Valentin Schneider <vschneid@redhat.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Zqiang <qiang.zhang1211@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Currently, KASAN is unable to catch use-after-free in SLAB_TYPESAFE_BY_RCU
slabs because use-after-free is allowed within the RCU grace period by
design.
Add a SLUB debugging feature which RCU-delays every individual
kmem_cache_free() before either actually freeing the object or handing it
off to KASAN, and change KASAN to poison freed objects as normal when this
option is enabled.
For now I've configured Kconfig.debug to default-enable this feature in the
KASAN GENERIC and SW_TAGS modes; I'm not enabling it by default in HW_TAGS
mode because I'm not sure if it might have unwanted performance degradation
effects there.
Note that this is mostly useful with KASAN in the quarantine-based GENERIC
mode; SLAB_TYPESAFE_BY_RCU slabs are basically always also slabs with a
->ctor, and KASAN's assign_tag() currently has to assign fixed tags for
those, reducing the effectiveness of SW_TAGS/HW_TAGS mode.
(A possible future extension of this work would be to also let SLUB call
the ->ctor() on every allocation instead of only when the slab page is
allocated; then tag-based modes would be able to assign new tags on every
reallocation.)
Tested-by: syzbot+263726e59eab6b442723@syzkaller.appspotmail.com
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Acked-by: Marco Elver <elver@google.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz> #slab
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Currently, when KASAN is combined with init-on-free behavior, the
initialization happens before KASAN's "invalid free" checks.
More importantly, a subsequent commit will want to RCU-delay the actual
SLUB freeing of an object, and we'd like KASAN to still validate
synchronously that freeing the object is permitted. (Otherwise this
change will make the existing testcase kmem_cache_invalid_free fail.)
So add a new KASAN hook that allows KASAN to pre-validate a
kmem_cache_free() operation before SLUB actually starts modifying the
object or its metadata.
Inside KASAN, this:
- moves checks from poison_slab_object() into check_slab_allocation()
- moves kasan_arch_is_ready() up into callers of poison_slab_object()
- removes "ip" argument of poison_slab_object() and __kasan_slab_free()
(since those functions no longer do any reporting)
Acked-by: Vlastimil Babka <vbabka@suse.cz> #slub
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
The SLAB_KASAN flag prevents merging of caches in some configurations,
which is handled in a rather complicated way via kasan_never_merge().
Since we now have a generic SLAB_NO_MERGE flag, we can instead use it
for KASAN caches in addition to SLAB_KASAN in those configurations,
and simplify the SLAB_NEVER_MERGE handling.
Tested-by: Xiongwei Song <xiongwei.song@windriver.com>
Reviewed-by: Chengming Zhou <chengming.zhou@linux.dev>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Tested-by: David Rientjes <rientjes@google.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Use the KASAN_TAG_KERNEL marco instead of open-coding 0xff in the mm code.
This macro is provided by include/linux/kasan-tags.h, which does not
include any other headers, so it's safe to include it into mm.h without
causing circular include dependencies.
Link: https://lkml.kernel.org/r/71db9087b0aebb6c4dccbc609cc0cd50621533c7.1703188911.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Marco Elver <elver@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Rename kasan_unpoison_object_data to kasan_unpoison_new_object and add a
documentation comment. Do the same for kasan_poison_object_data.
The new names and the comments should suggest the users that these hooks
are intended for internal use by the slab allocator.
The following patch will remove non-slab-internal uses of these hooks.
No functional changes.
[andreyknvl@google.com: update references to renamed functions in comments]
Link: https://lkml.kernel.org/r/20231221180637.105098-1-andrey.konovalov@linux.dev
Link: https://lkml.kernel.org/r/eab156ebbd635f9635ef67d1a4271f716994e628.1703024586.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Alexander Lobakin <alobakin@pm.me>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Breno Leitao <leitao@debian.org>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Update kasan_mempool_unpoison_object to properly poison the redzone and
save alloc strack traces for kmalloc and slab pools.
As a part of this change, split out and use a unpoison_slab_object helper
function from __kasan_slab_alloc.
[nathan@kernel.org: mark unpoison_slab_object() as static]
Link: https://lkml.kernel.org/r/20231221180042.104694-1-andrey.konovalov@linux.dev
Link: https://lkml.kernel.org/r/05ad235da8347cfe14d496d01b2aaf074b4f607c.1703024586.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Cc: Alexander Lobakin <alobakin@pm.me>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Breno Leitao <leitao@debian.org>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Marco Elver <elver@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Make kasan_mempool_poison_object save free stack traces for slab and
kmalloc mempools when the object is freed into the mempool.
Also simplify and rename ____kasan_slab_free to poison_slab_object and do
a few other reability changes.
Link: https://lkml.kernel.org/r/413a7c7c3344fb56809853339ffaabc9e4905e94.1703024586.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Cc: Alexander Lobakin <alobakin@pm.me>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Breno Leitao <leitao@debian.org>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Marco Elver <elver@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Introduce and document a new kasan_mempool_unpoison_pages hook to be used
by the mempool code instead of kasan_unpoison_pages.
This hook is not functionally different from kasan_unpoison_pages, but
using it improves the mempool code readability.
Link: https://lkml.kernel.org/r/239bd9af6176f2cc59f5c25893eb36143184daff.1703024586.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Cc: Alexander Lobakin <alobakin@pm.me>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Breno Leitao <leitao@debian.org>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Marco Elver <elver@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Introduce and document a kasan_mempool_poison_pages hook to be used by the
mempool code instead of kasan_poison_pages.
Compated to kasan_poison_pages, the new hook:
1. For the tag-based modes, skips checking and poisoning allocations that
were not tagged due to sampling.
2. Checks for double-free and invalid-free bugs.
In the future, kasan_poison_pages can also be updated to handle #2, but
this is out-of-scope of this series.
Link: https://lkml.kernel.org/r/88dc7340cce28249abf789f6e0c792c317df9ba5.1703024586.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Cc: Alexander Lobakin <alobakin@pm.me>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Breno Leitao <leitao@debian.org>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Marco Elver <elver@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Introduce and document a kasan_mempool_unpoison_object hook.
This hook serves as a replacement for the generic kasan_unpoison_range
that the mempool code relies on right now. mempool will be updated to use
the new hook in one of the following patches.
For now, define the new hook to be identical to kasan_unpoison_range. One
of the following patches will update it to add stack trace collection.
Link: https://lkml.kernel.org/r/dae25f0e18ed8fd50efe509c5b71a0592de5c18d.1703024586.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Cc: Alexander Lobakin <alobakin@pm.me>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Breno Leitao <leitao@debian.org>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Marco Elver <elver@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Add a return value for kasan_mempool_poison_object that lets the caller
know whether the allocation is affected by a double-free or an
invalid-free bug. The caller can use this return value to stop operating
on the object.
Also introduce a check_page_allocation helper function to improve the code
readability.
Link: https://lkml.kernel.org/r/618af65273875fb9f56954285443279b15f1fcd9.1703024586.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Cc: Alexander Lobakin <alobakin@pm.me>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Breno Leitao <leitao@debian.org>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Marco Elver <elver@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Move kasan_mempool_poison_object after all slab-related KASAN hooks.
This is a preparatory change for the following patches in this series.
No functional changes.
Link: https://lkml.kernel.org/r/23ea215409f43c13cdf9ecc454501a264c107d67.1703024586.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Cc: Alexander Lobakin <alobakin@pm.me>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Breno Leitao <leitao@debian.org>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Marco Elver <elver@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "kasan: save mempool stack traces".
This series updates KASAN to save alloc and free stack traces for
secondary-level allocators that cache and reuse allocations internally
instead of giving them back to the underlying allocator (e.g. mempool).
As a part of this change, introduce and document a set of KASAN hooks:
bool kasan_mempool_poison_pages(struct page *page, unsigned int order);
void kasan_mempool_unpoison_pages(struct page *page, unsigned int order);
bool kasan_mempool_poison_object(void *ptr);
void kasan_mempool_unpoison_object(void *ptr, size_t size);
and use them in the mempool code.
Besides mempool, skbuff and io_uring also cache allocations and already
use KASAN hooks to poison those. Their code is updated to use the new
mempool hooks.
The new hooks save alloc and free stack traces (for normal kmalloc and
slab objects; stack traces for large kmalloc objects and page_alloc are
not supported by KASAN yet), improve the readability of the users' code,
and also allow the users to prevent double-free and invalid-free bugs; see
the patches for the details.
This patch (of 21):
Rename kasan_slab_free_mempool to kasan_mempool_poison_object.
kasan_slab_free_mempool is a slightly confusing name: it is unclear
whether this function poisons the object when it is freed into mempool or
does something when the object is freed from mempool to the underlying
allocator.
The new name also aligns with other mempool-related KASAN hooks added in
the following patches in this series.
Link: https://lkml.kernel.org/r/cover.1703024586.git.andreyknvl@google.com
Link: https://lkml.kernel.org/r/c5618685abb7cdbf9fb4897f565e7759f601da84.1703024586.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Cc: Alexander Lobakin <alobakin@pm.me>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Breno Leitao <leitao@debian.org>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Marco Elver <elver@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
On arm64, building with CONFIG_KASAN_HW_TAGS now causes a compile-time
error:
mm/kasan/report.c: In function 'kasan_non_canonical_hook':
mm/kasan/report.c:637:20: error: 'KASAN_SHADOW_OFFSET' undeclared (first use in this function)
637 | if (addr < KASAN_SHADOW_OFFSET)
| ^~~~~~~~~~~~~~~~~~~
mm/kasan/report.c:637:20: note: each undeclared identifier is reported only once for each function it appears in
mm/kasan/report.c:640:77: error: expected expression before ';' token
640 | orig_addr = (addr - KASAN_SHADOW_OFFSET) << KASAN_SHADOW_SCALE_SHIFT;
This was caused by removing the dependency on CONFIG_KASAN_INLINE that
used to prevent this from happening. Use the more specific dependency
on KASAN_SW_TAGS || KASAN_GENERIC to only ignore the function for hwasan
mode.
Link: https://lkml.kernel.org/r/20231016200925.984439-1-arnd@kernel.org
Fixes: 12ec6a919b0f ("kasan: print the original fault addr when access invalid shadow")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Haibo Li <haibo.li@mediatek.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
when the checked address is illegal,the corresponding shadow address from
kasan_mem_to_shadow may have no mapping in mmu table. Access such shadow
address causes kernel oops. Here is a sample about oops on arm64(VA
39bit) with KASAN_SW_TAGS and KASAN_OUTLINE on:
[ffffffb80aaaaaaa] pgd=000000005d3ce003, p4d=000000005d3ce003,
pud=000000005d3ce003, pmd=0000000000000000
Internal error: Oops: 0000000096000006 [#1] PREEMPT SMP
Modules linked in:
CPU: 3 PID: 100 Comm: sh Not tainted 6.6.0-rc1-dirty #43
Hardware name: linux,dummy-virt (DT)
pstate: 80000005 (Nzcv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : __hwasan_load8_noabort+0x5c/0x90
lr : do_ib_ob+0xf4/0x110
ffffffb80aaaaaaa is the shadow address for efffff80aaaaaaaa.
The problem is reading invalid shadow in kasan_check_range.
The generic kasan also has similar oops.
It only reports the shadow address which causes oops but not
the original address.
Commit 2f004eea0fc8("x86/kasan: Print original address on #GP")
introduce to kasan_non_canonical_hook but limit it to KASAN_INLINE.
This patch extends it to KASAN_OUTLINE mode.
Link: https://lkml.kernel.org/r/20231009073748.159228-1-haibo.li@mediatek.com
Fixes: 2f004eea0fc8("x86/kasan: Print original address on #GP")
Signed-off-by: Haibo Li <haibo.li@mediatek.com>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Haibo Li <haibo.li@mediatek.com>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
As Linus suggested, __HAVE_ARCH_XYZ is "stupid" and "having historical
uses of it doesn't make it good". So migrate __HAVE_ARCH_SHADOW_MAP to
separate macros named after the respective functions.
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: WANG Xuerui <git@xen0n.name>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Alexei Starovoitov says:
====================
The following pull-request contains BPF updates for your *net-next* tree.
We've added 73 non-merge commits during the last 9 day(s) which contain
a total of 79 files changed, 5275 insertions(+), 600 deletions(-).
The main changes are:
1) Basic BTF validation in libbpf, from Andrii Nakryiko.
2) bpf_assert(), bpf_throw(), exceptions in bpf progs, from Kumar Kartikeya Dwivedi.
3) next_thread cleanups, from Oleg Nesterov.
4) Add mcpu=v4 support to arm32, from Puranjay Mohan.
5) Add support for __percpu pointers in bpf progs, from Yonghong Song.
6) Fix bpf tailcall interaction with bpf trampoline, from Leon Hwang.
7) Raise irq_work in bpf_mem_alloc while irqs are disabled to improve refill probabablity, from Hou Tao.
Please consider pulling these changes from:
git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git
Thanks a lot!
Also thanks to reporters, reviewers and testers of commits in this pull-request:
Alan Maguire, Andrey Konovalov, Dave Marchevsky, "Eric W. Biederman",
Jiri Olsa, Maciej Fijalkowski, Quentin Monnet, Russell King (Oracle),
Song Liu, Stanislav Fomichev, Yonghong Song
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
We require access to this kasan helper in BPF code in the next patch
where we have to unpoison the task stack when we unwind and reset the
stack frame from bpf_throw, and it never really unpoisons the poisoned
stack slots on entry when compiler instrumentation is generated by
CONFIG_KASAN_STACK and inline instrumentation is supported.
Also, remove the declaration from mm/kasan/kasan.h as we put it in the
header file kasan.h.
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Suggested-by: Andrey Konovalov <andreyknvl@gmail.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Link: https://lore.kernel.org/r/20230912233214.1518551-10-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
MIPS, LoongArch and some other architectures have many holes between
different segments and the valid address space (256T available) is
insufficient to map all these segments to kasan shadow memory with the
common formula provided by kasan core. So we need architecture specific
mapping formulas to ensure different segments are mapped individually,
and only limited space lengths of those specific segments are mapped to
shadow.
Therefore, when the incoming address is converted to a shadow, we need
to add a condition to determine whether it is valid.
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Signed-off-by: Qing Zhang <zhangqing@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
gcc-13 warns about function definitions for builtin interfaces that have a
different prototype, e.g.:
In file included from kasan_test.c:31:
kasan.h:574:6: error: conflicting types for built-in function '__asan_register_globals'; expected 'void(void *, long int)' [-Werror=builtin-declaration-mismatch]
574 | void __asan_register_globals(struct kasan_global *globals, size_t size);
kasan.h:577:6: error: conflicting types for built-in function '__asan_alloca_poison'; expected 'void(void *, long int)' [-Werror=builtin-declaration-mismatch]
577 | void __asan_alloca_poison(unsigned long addr, size_t size);
kasan.h:580:6: error: conflicting types for built-in function '__asan_load1'; expected 'void(void *)' [-Werror=builtin-declaration-mismatch]
580 | void __asan_load1(unsigned long addr);
kasan.h:581:6: error: conflicting types for built-in function '__asan_store1'; expected 'void(void *)' [-Werror=builtin-declaration-mismatch]
581 | void __asan_store1(unsigned long addr);
kasan.h:643:6: error: conflicting types for built-in function '__hwasan_tag_memory'; expected 'void(void *, unsigned char, long int)' [-Werror=builtin-declaration-mismatch]
643 | void __hwasan_tag_memory(unsigned long addr, u8 tag, unsigned long size);
The two problems are:
- Addresses are passes as 'unsigned long' in the kernel, but gcc-13
expects a 'void *'.
- sizes meant to use a signed ssize_t rather than size_t.
Change all the prototypes to match these. Using 'void *' consistently for
addresses gets rid of a couple of type casts, so push that down to the
leaf functions where possible.
This now passes all randconfig builds on arm, arm64 and x86, but I have
not tested it on the other architectures that support kasan, since they
tend to fail randconfig builds in other ways. This might fail if any of
the 32-bit architectures expect a 'long' instead of 'int' for the size
argument.
The __asan_allocas_unpoison() function prototype is somewhat weird, since
it uses a pointer for 'stack_top' and an size_t for 'stack_bottom'. This
looks like it is meant to be 'addr' and 'size' like the others, but the
implementation clearly treats them as 'top' and 'bottom'.
Link: https://lkml.kernel.org/r/20230509145735.9263-2-arnd@kernel.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Marco Elver <elver@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
struct 'kasan_cache' has a member 'is_kmalloc' indicating whether its host
kmem_cache is a kmalloc cache. With newly introduced is_kmalloc_cache()
helper, 'is_kmalloc' and its related function can be replaced and removed.
Also 'kasan_cache' is only needed by KASAN generic mode, and not by SW/HW
tag modes, so refine its protection macro accordingly, suggested by Andrey
Konoval.
Link: https://lkml.kernel.org/r/20230104060605.930910-2-feng.tang@intel.com
Signed-off-by: Feng Tang <feng.tang@intel.com>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
As Hardware Tag-Based KASAN is intended to be used in production, its
performance impact is crucial. As page_alloc allocations tend to be big,
tagging and checking all such allocations can introduce a significant
slowdown.
Add two new boot parameters that allow to alleviate that slowdown:
- kasan.page_alloc.sample, which makes Hardware Tag-Based KASAN tag only
every Nth page_alloc allocation with the order configured by the second
added parameter (default: tag every such allocation).
- kasan.page_alloc.sample.order, which makes sampling enabled by the first
parameter only affect page_alloc allocations with the order equal or
greater than the specified value (default: 3, see below).
The exact performance improvement caused by using the new parameters
depends on their values and the applied workload.
The chosen default value for kasan.page_alloc.sample.order is 3, which
matches both PAGE_ALLOC_COSTLY_ORDER and SKB_FRAG_PAGE_ORDER. This is
done for two reasons:
1. PAGE_ALLOC_COSTLY_ORDER is "the order at which allocations are deemed
costly to service", which corresponds to the idea that only large and
thus costly allocations are supposed to sampled.
2. One of the workloads targeted by this patch is a benchmark that sends
a large amount of data over a local loopback connection. Most multi-page
data allocations in the networking subsystem have the order of
SKB_FRAG_PAGE_ORDER (or PAGE_ALLOC_COSTLY_ORDER).
When running a local loopback test on a testing MTE-enabled device in sync
mode, enabling Hardware Tag-Based KASAN introduces a ~50% slowdown.
Applying this patch and setting kasan.page_alloc.sampling to a value
higher than 1 allows to lower the slowdown. The performance improvement
saturates around the sampling interval value of 10 with the default
sampling page order of 3. This lowers the slowdown to ~20%. The slowdown
in real scenarios involving the network will likely be better.
Enabling page_alloc sampling has a downside: KASAN misses bad accesses to
a page_alloc allocation that has not been tagged. This lowers the value
of KASAN as a security mitigation.
However, based on measuring the number of page_alloc allocations of
different orders during boot in a test build, sampling with the default
kasan.page_alloc.sample.order value affects only ~7% of allocations. The
rest ~93% of allocations are still checked deterministically.
Link: https://lkml.kernel.org/r/129da0614123bb85ed4dd61ae30842b2dd7c903f.1671471846.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: Mark Brand <markbrand@google.com>
Cc: Peter Collingbourne <pcc@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
When kasan is enabled for slab/slub, it may save kasan' free_meta
data in the former part of slab object data area in slab object's
free path, which works fine.
There is ongoing effort to extend slub's debug function which will
redzone the latter part of kmalloc object area, and when both of
the debug are enabled, there is possible conflict, especially when
the kmalloc object has small size, as caught by 0Day bot [1].
To solve it, slub code needs to know the in-object kasan's meta
data size. Currently, there is existing kasan_metadata_size()
which returns the kasan's metadata size inside slub's metadata
area, so extend it to also cover the in-object meta size by
adding a boolean flag 'in_object'.
There is no functional change to existing code logic.
[1]. https://lore.kernel.org/lkml/YuYm3dWwpZwH58Hu@xsang-OptiPlex-9020/
Reported-by: kernel test robot <oliver.sang@intel.com>
Suggested-by: Andrey Konovalov <andreyknvl@gmail.com>
Signed-off-by: Feng Tang <feng.tang@intel.com>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Right now, kasan_cache_create() assigns SLAB_KASAN for all KASAN modes and
then sets up metadata-related cache parameters for the Generic mode.
SLAB_KASAN is used in two places:
1. In slab_ksize() to account for per-object metadata when
calculating the size of the accessible memory within the object.
2. In slab_common.c via kasan_never_merge() to prevent merging of
caches with per-object metadata.
Both cases are only relevant when per-object metadata is present, which is
only the case with the Generic mode.
Thus, assign SLAB_KASAN and define kasan_cache_create() only for the
Generic mode.
Also update the SLAB_KASAN-related comment.
Link: https://lkml.kernel.org/r/61faa2aa1906e2d02c97d00ddf99ce8911dda095.1662411799.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Peter Collingbourne <pcc@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Hide the definitions of alloc_meta_offset and free_meta_offset under an
ifdef CONFIG_KASAN_GENERIC check, as these fields are now only used when
the Generic mode is enabled.
Link: https://lkml.kernel.org/r/d4bafa0534facafd1a23c465a94261e64f366493.1662411799.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Peter Collingbourne <pcc@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
KASAN prevents merging of slab caches whose objects have per-object
metadata stored in redzones.
As now only the Generic mode uses per-object metadata, define
kasan_never_merge() only for this mode.
Link: https://lkml.kernel.org/r/81ed01f29ff3443580b7e2fe362a8b47b1e8006d.1662411799.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Peter Collingbourne <pcc@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
KASAN provides a helper for calculating the size of per-object metadata
stored in the redzone.
As now only the Generic mode uses per-object metadata, only define
kasan_metadata_size() for this mode.
Link: https://lkml.kernel.org/r/8f81d4938b80446bc72538a08217009f328a3e23.1662411799.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Peter Collingbourne <pcc@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
- Move kasan_save_enable/restore_multi_shot() declarations to
mm/kasan/kasan.h, as there is no need for them to be visible outside
of KASAN implementation.
- Only define and export these functions when KASAN tests are enabled.
- Move their definitions closer to other test-related code in report.c.
Link: https://lkml.kernel.org/r/6ba637333b78447f027d775f2d55ab1a40f63c99.1646237226.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Marco Elver <elver@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Async mode support has already been implemented in commit e80a76aa1a
("kasan, arm64: tests supports for HW_TAGS async mode") but then got
accidentally broken in commit 99734b535d ("kasan: detect false-positives
in tests").
Restore the changes removed by the latter patch and adapt them for asymm
mode: add a sync_fault flag to kunit_kasan_expectation that only get set
if the MTE fault was synchronous, and reenable MTE on such faults in
tests.
Also rename kunit_kasan_expectation to kunit_kasan_status and move its
definition to mm/kasan/kasan.h from include/linux/kasan.h, as this
structure is only internally used by KASAN. Also put the structure
definition under IS_ENABLED(CONFIG_KUNIT).
Link: https://lkml.kernel.org/r/133970562ccacc93ba19d754012c562351d4a8c8.1645033139.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Cc: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The kernel can use to allocate executable memory. The only supported
way to do that is via __vmalloc_node_range() with the executable bit set
in the prot argument. (vmap() resets the bit via pgprot_nx()).
Once tag-based KASAN modes start tagging vmalloc allocations, executing
code from such allocations will lead to the PC register getting a tag,
which is not tolerated by the kernel.
Only tag the allocations for normal kernel pages.
[andreyknvl@google.com: pass KASAN_VMALLOC_PROT_NORMAL to kasan_unpoison_vmalloc()]
Link: https://lkml.kernel.org/r/9230ca3d3e40ffca041c133a524191fd71969a8d.1646233925.git.andreyknvl@google.com
[andreyknvl@google.com: support tagged vmalloc mappings]
Link: https://lkml.kernel.org/r/2f6605e3a358cf64d73a05710cb3da356886ad29.1646233925.git.andreyknvl@google.com
[andreyknvl@google.com: don't unintentionally disabled poisoning]
Link: https://lkml.kernel.org/r/de4587d6a719232e83c760113e46ed2d4d8da61e.1646757322.git.andreyknvl@google.com
Link: https://lkml.kernel.org/r/fbfd9939a4dc375923c9a5c6b9e7ab05c26b8c6b.1643047180.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Acked-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Collingbourne <pcc@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add vmalloc tagging support to HW_TAGS KASAN.
The key difference between HW_TAGS and the other two KASAN modes when it
comes to vmalloc: HW_TAGS KASAN can only assign tags to physical memory.
The other two modes have shadow memory covering every mapped virtual
memory region.
Make __kasan_unpoison_vmalloc() for HW_TAGS KASAN:
- Skip non-VM_ALLOC mappings as HW_TAGS KASAN can only tag a single
mapping of normal physical memory; see the comment in the function.
- Generate a random tag, tag the returned pointer and the allocation,
and initialize the allocation at the same time.
- Propagate the tag into the page stucts to allow accesses through
page_address(vmalloc_to_page()).
The rest of vmalloc-related KASAN hooks are not needed:
- The shadow-related ones are fully skipped.
- __kasan_poison_vmalloc() is kept as a no-op with a comment.
Poisoning and zeroing of physical pages that are backing vmalloc()
allocations are skipped via __GFP_SKIP_KASAN_UNPOISON and
__GFP_SKIP_ZERO: __kasan_unpoison_vmalloc() does that instead.
Enabling CONFIG_KASAN_VMALLOC with HW_TAGS is not yet allowed.
Link: https://lkml.kernel.org/r/d19b2e9e59a9abc59d05b72dea8429dcaea739c6.1643047180.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Co-developed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Acked-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Collingbourne <pcc@google.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add vmalloc tagging support to SW_TAGS KASAN.
- __kasan_unpoison_vmalloc() now assigns a random pointer tag, poisons
the virtual mapping accordingly, and embeds the tag into the returned
pointer.
- __get_vm_area_node() (used by vmalloc() and vmap()) and
pcpu_get_vm_areas() save the tagged pointer into vm_struct->addr
(note: not into vmap_area->addr).
This requires putting kasan_unpoison_vmalloc() after
setup_vmalloc_vm[_locked](); otherwise the latter will overwrite the
tagged pointer. The tagged pointer then is naturally propagateed to
vmalloc() and vmap().
- vm_map_ram() returns the tagged pointer directly.
As a result of this change, vm_struct->addr is now tagged.
Enabling KASAN_VMALLOC with SW_TAGS is not yet allowed.
Link: https://lkml.kernel.org/r/4a78f3c064ce905e9070c29733aca1dd254a74f1.1643047180.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Acked-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Collingbourne <pcc@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add wrappers around functions that [un]poison memory for vmalloc
allocations. These functions will be used by HW_TAGS KASAN and therefore
need to be disabled when kasan=off command line argument is provided.
This patch does no functional changes for software KASAN modes.
Link: https://lkml.kernel.org/r/3b8728eac438c55389fb0f9a8a2145d71dd77487.1643047180.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Acked-by: Marco Elver <elver@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Collingbourne <pcc@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Group functions that [de]populate shadow memory for vmalloc. Group
functions that [un]poison memory for vmalloc.
This patch does no functional changes but prepares KASAN code for adding
vmalloc support to HW_TAGS KASAN.
Link: https://lkml.kernel.org/r/aeef49eb249c206c4c9acce2437728068da74c28.1643047180.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Acked-by: Marco Elver <elver@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Collingbourne <pcc@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Rename kasan_free_shadow to kasan_free_module_shadow and
kasan_module_alloc to kasan_alloc_module_shadow.
These functions are used to allocate/free shadow memory for kernel modules
when KASAN_VMALLOC is not enabled. The new names better reflect their
purpose.
Also reword the comment next to their declaration to improve clarity.
Link: https://lkml.kernel.org/r/36db32bde765d5d0b856f77d2d806e838513fe84.1643047180.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Collingbourne <pcc@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently, the code responsible for initializing and poisoning memory in
post_alloc_hook() is scattered across two locations: kasan_alloc_pages()
hook for HW_TAGS KASAN and post_alloc_hook() itself. This is confusing.
This and a few following patches combine the code from these two
locations. Along the way, these patches do a step-by-step restructure the
many performed checks to make them easier to follow.
Replace the only caller of kasan_alloc_pages() with its implementation.
As kasan_has_integrated_init() is only true when CONFIG_KASAN_HW_TAGS is
enabled, moving the code does no functional changes.
Also move init and init_tags variables definitions out of
kasan_has_integrated_init() clause in post_alloc_hook(), as they have the
same values regardless of what the if condition evaluates to.
This patch is not useful by itself but makes the simplifications in the
following patches easier to follow.
Link: https://lkml.kernel.org/r/5ac7e0b30f5cbb177ec363ddd7878a3141289592.1643047180.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Acked-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Collingbourne <pcc@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently, the code responsible for initializing and poisoning memory in
free_pages_prepare() is scattered across two locations: kasan_free_pages()
for HW_TAGS KASAN and free_pages_prepare() itself. This is confusing.
This and a few following patches combine the code from these two
locations. Along the way, these patches also simplify the performed
checks to make them easier to follow.
Replaces the only caller of kasan_free_pages() with its implementation.
As kasan_has_integrated_init() is only true when CONFIG_KASAN_HW_TAGS is
enabled, moving the code does no functional changes.
This patch is not useful by itself but makes the simplifications in the
following patches easier to follow.
Link: https://lkml.kernel.org/r/303498d15840bb71905852955c6e2390ecc87139.1643047180.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Acked-by: Marco Elver <elver@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Collingbourne <pcc@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Linus Torvalds