kasan, vmalloc: only tag normal vmalloc allocations

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>

kasan, vmalloc: add vmalloc tagging for HW_TAGS

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>

kasan, page_alloc: allow skipping memory init for HW_TAGS

Add a new GFP flag __GFP_SKIP_ZERO that allows to skip memory
initialization.  The flag is only effective with HW_TAGS KASAN.

This flag will be used by vmalloc code for page_alloc allocations backing
vmalloc() mappings in a following patch.  The reason to skip memory
initialization for these pages in page_alloc is because vmalloc code will
be initializing them instead.

With the current implementation, when __GFP_SKIP_ZERO is provided,
__GFP_ZEROTAGS is ignored.  This doesn't matter, as these two flags are
never provided at the same time.  However, if this is changed in the
future, this particular implementation detail can be changed as well.

Link: https://lkml.kernel.org/r/0d53efeff345de7d708e0baa0d8829167772521e.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>

kasan, page_alloc: allow skipping unpoisoning for HW_TAGS

Add a new GFP flag __GFP_SKIP_KASAN_UNPOISON that allows skipping KASAN
poisoning for page_alloc allocations.  The flag is only effective with
HW_TAGS KASAN.

This flag will be used by vmalloc code for page_alloc allocations backing
vmalloc() mappings in a following patch.  The reason to skip KASAN
poisoning for these pages in page_alloc is because vmalloc code will be
poisoning them instead.

Also reword the comment for __GFP_SKIP_KASAN_POISON.

Link: https://lkml.kernel.org/r/35c97d77a704f6ff971dd3bfe4be95855744108e.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>

kasan, mm: only define ___GFP_SKIP_KASAN_POISON with HW_TAGS

Only define the ___GFP_SKIP_KASAN_POISON flag when CONFIG_KASAN_HW_TAGS is
enabled.

This patch it not useful by itself, but it prepares the code for additions
of new KASAN-specific GFP patches.

Link: https://lkml.kernel.org/r/44e5738a584c11801b2b8f1231898918efc8634a.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>

kasan, vmalloc: unpoison VM_ALLOC pages after mapping

Make KASAN unpoison vmalloc mappings after they have been mapped in when
it's possible: for vmalloc() (indentified via VM_ALLOC) and vm_map_ram().

The reasons for this are:

 - For vmalloc() and vm_map_ram(): pages don't get unpoisoned in case
   mapping them fails.

 - For vmalloc(): HW_TAGS KASAN needs pages to be mapped to set tags via
   kasan_unpoison_vmalloc().

As a part of these changes, the return value of __vmalloc_node_range() is
changed to area->addr.  This is a non-functional change, as
__vmalloc_area_node() returns area->addr anyway.

Link: https://lkml.kernel.org/r/fcb98980e6fcd3c4be6acdcb5d6110898ef28548.1643047180.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>

kasan, vmalloc, arm64: mark vmalloc mappings as pgprot_tagged

HW_TAGS KASAN relies on ARM Memory Tagging Extension (MTE).  With MTE, a
memory region must be mapped as MT_NORMAL_TAGGED to allow setting memory
tags via MTE-specific instructions.

Add proper protection bits to vmalloc() allocations.  These allocations
are always backed by page_alloc pages, so the tags will actually be
getting set on the corresponding physical memory.

Link: https://lkml.kernel.org/r/983fc33542db2f6b1e77b34ca23448d4640bbb9e.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>

kasan, vmalloc: add vmalloc tagging for SW_TAGS

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>

kasan, arm64: reset pointer tags of vmapped stacks

Once tag-based KASAN modes start tagging vmalloc() allocations, kernel
stacks start getting tagged if CONFIG_VMAP_STACK is enabled.

Reset the tag of kernel stack pointers after allocation in
arch_alloc_vmap_stack().

For SW_TAGS KASAN, when CONFIG_KASAN_STACK is enabled, the instrumentation
can't handle the SP register being tagged.

For HW_TAGS KASAN, there's no instrumentation-related issues.  However,
the impact of having a tagged SP register needs to be properly evaluated,
so keep it non-tagged for now.

Note, that the memory for the stack allocation still gets tagged to catch
vmalloc-into-stack out-of-bounds accesses.

[andreyknvl@google.com: fix case when a stack is retrieved from cached_stacks]
Link: https://lkml.kernel.org/r/f50c5f96ef896d7936192c888b0c0a7674e33184.1644943792.git.andreyknvl@google.com
[dan.carpenter@oracle.com: remove unnecessary check in alloc_thread_stack_node()]
Link: https://lkml.kernel.org/r/20220301080706.GB17208@kili
Link: https://lkml.kernel.org/r/698c5ab21743c796d46c15d075b9481825973e34.1643047180.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Marco Elver <elver@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: 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>

kasan, fork: reset pointer tags of vmapped stacks

Once tag-based KASAN modes start tagging vmalloc() allocations, kernel
stacks start getting tagged if CONFIG_VMAP_STACK is enabled.

Reset the tag of kernel stack pointers after allocation in
alloc_thread_stack_node().

For SW_TAGS KASAN, when CONFIG_KASAN_STACK is enabled, the instrumentation
can't handle the SP register being tagged.

For HW_TAGS KASAN, there's no instrumentation-related issues.  However,
the impact of having a tagged SP register needs to be properly evaluated,
so keep it non-tagged for now.

Note, that the memory for the stack allocation still gets tagged to catch
vmalloc-into-stack out-of-bounds accesses.

Link: https://lkml.kernel.org/r/c6c96f012371ecd80e1936509ebcd3b07a5956f7.1643047180.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>

kasan, vmalloc: reset tags in vmalloc functions

In preparation for adding vmalloc support to SW/HW_TAGS KASAN, reset
pointer tags in functions that use pointer values in range checks.

vread() is a special case here.  Despite the untagging of the addr pointer
in its prologue, the accesses performed by vread() are checked.

Instead of accessing the virtual mappings though addr directly, vread()
recovers the physical address via page_address(vmalloc_to_page()) and
acceses that.  And as page_address() recovers the pointer tag, the
accesses get checked.

Link: https://lkml.kernel.org/r/046003c5f683cacb0ba18e1079e9688bb3dca943.1643047180.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>

kasan: add wrappers for vmalloc hooks

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>

kasan: reorder vmalloc hooks

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>

kasan, vmalloc: drop outdated VM_KASAN comment

The comment about VM_KASAN in include/linux/vmalloc.c is outdated.
VM_KASAN is currently only used to mark vm_areas allocated for kernel
modules when CONFIG_KASAN_VMALLOC is disabled.

Drop the comment.

Link: https://lkml.kernel.org/r/780395afea83a147b3b5acc36cf2e38f7f8479f9.1643047180.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>

kasan, x86, arm64, s390: rename functions for modules shadow

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>

kasan: define KASAN_VMALLOC_INVALID for SW_TAGS

In preparation for adding vmalloc support to SW_TAGS KASAN, provide a
KASAN_VMALLOC_INVALID definition for it.

HW_TAGS KASAN won't be using this value, as it falls back onto page_alloc
for poisoning freed vmalloc() memory.

Link: https://lkml.kernel.org/r/1daaaafeb148a7ae8285265edc97d7ca07b6a07d.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>

kasan: clean up metadata byte definitions

Most of the metadata byte values are only used for Generic KASAN.

Remove KASAN_KMALLOC_FREETRACK definition for !CONFIG_KASAN_GENERIC case,
and put it along with other metadata values for the Generic mode under a
corresponding ifdef.

Link: https://lkml.kernel.org/r/ac11d6e9e007c95e472e8fdd22efb6074ef3c6d8.1643047180.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>

kasan, page_alloc: rework kasan_unpoison_pages call site

Rework the checks around kasan_unpoison_pages() call in post_alloc_hook().

The logical condition for calling this function is:

 - If a software KASAN mode is enabled, we need to mark shadow memory.

 - Otherwise, HW_TAGS KASAN is enabled, and it only makes sense to set
   tags if they haven't already been cleared by tag_clear_highpage(),
   which is indicated by init_tags.

This patch concludes the changes for post_alloc_hook().

Link: https://lkml.kernel.org/r/0ecebd0d7ccd79150e3620ea4185a32d3dfe912f.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>

kasan, page_alloc: move kernel_init_free_pages in post_alloc_hook

Pull the kernel_init_free_pages() call in post_alloc_hook() out of the big
if clause for better code readability.  This also allows for more
simplifications in the following patch.

This patch does no functional changes.

Link: https://lkml.kernel.org/r/a7a76456501eb37ddf9fca6529cee9555e59cdb1.1643047180.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>

kasan, page_alloc: move SetPageSkipKASanPoison in post_alloc_hook

Pull the SetPageSkipKASanPoison() call in post_alloc_hook() out of the big
if clause for better code readability.  This also allows for more
simplifications in the following patches.

Also turn the kasan_has_integrated_init() check into the proper
kasan_hw_tags_enabled() one.  These checks evaluate to the same value, but
logically skipping kasan poisoning has nothing to do with integrated init.

Link: https://lkml.kernel.org/r/7214c1698b754ccfaa44a792113c95cc1f807c48.1643047180.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>

kasan, page_alloc: combine tag_clear_highpage calls in post_alloc_hook

Move tag_clear_highpage() loops out of the kasan_has_integrated_init()
clause as a code simplification.

This patch does no functional changes.

Link: https://lkml.kernel.org/r/587e3fc36358b88049320a89cc8dc6deaecb0cda.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>

kasan, page_alloc: merge kasan_alloc_pages into post_alloc_hook

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>

kasan, page_alloc: refactor init checks in post_alloc_hook

Separate code for zeroing memory from the code clearing tags in
post_alloc_hook().

This patch is not useful by itself but makes the simplifications in the
following patches easier to follow.

This patch does no functional changes.

Link: https://lkml.kernel.org/r/2283fde963adfd8a2b29a92066f106cc16661a3c.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>

kasan: only apply __GFP_ZEROTAGS when memory is zeroed

__GFP_ZEROTAGS should only be effective if memory is being zeroed.
Currently, hardware tag-based KASAN violates this requirement.

Fix by including an initialization check along with checking for
__GFP_ZEROTAGS.

Link: https://lkml.kernel.org/r/f4f4593f7f675262d29d07c1938db5bd0cd5e285.1643047180.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>

mm: clarify __GFP_ZEROTAGS comment

__GFP_ZEROTAGS is intended as an optimization: if memory is zeroed during
allocation, it's possible to set memory tags at the same time with little
performance impact.

Clarify this intention of __GFP_ZEROTAGS in the comment.

Link: https://lkml.kernel.org/r/cdffde013973c5634a447513e10ec0d21e8eee29.1643047180.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>

kasan: drop skip_kasan_poison variable in free_pages_prepare

skip_kasan_poison is only used in a single place.  Call
should_skip_kasan_poison() directly for simplicity.

Link: https://lkml.kernel.org/r/1d33212e79bc9ef0b4d3863f903875823e89046f.1643047180.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Suggested-by: Marco Elver <elver@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>

kasan, page_alloc: init memory of skipped pages on free

Since commit 7a3b83537188 ("kasan: use separate (un)poison implementation
for integrated init"), when all init, kasan_has_integrated_init(), and
skip_kasan_poison are true, free_pages_prepare() doesn't initialize the
page.  This is wrong.

Fix it by remembering whether kasan_poison_pages() performed
initialization, and call kernel_init_free_pages() if it didn't.

Reordering kasan_poison_pages() and kernel_init_free_pages() is OK, since
kernel_init_free_pages() can handle poisoned memory.

Link: https://lkml.kernel.org/r/1d97df75955e52727a3dc1c4e33b3b50506fc3fd.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>

kasan, page_alloc: simplify kasan_poison_pages call site

Simplify the code around calling kasan_poison_pages() in
free_pages_prepare().

This patch does no functional changes.

Link: https://lkml.kernel.org/r/ae4f9bcf071577258e786bcec4798c145d718c46.1643047180.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>

kasan, page_alloc: merge kasan_free_pages into free_pages_prepare

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>

kasan, page_alloc: move tag_clear_highpage out of kernel_init_free_pages

Currently, kernel_init_free_pages() serves two purposes: it either only
zeroes memory or zeroes both memory and memory tags via a different code
path.  As this function has only two callers, each using only one code
path, this behaviour is confusing.

Pull the code that zeroes both memory and tags out of
kernel_init_free_pages().

As a result of this change, the code in free_pages_prepare() starts to
look complicated, but this is improved in the few following patches.
Those improvements are not integrated into this patch to make diffs easier
to read.

This patch does no functional changes.

Link: https://lkml.kernel.org/r/7719874e68b23902629c7cf19f966c4fd5f57979.1643047180.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>

kasan, page_alloc: deduplicate should_skip_kasan_poison

Patch series "kasan, vmalloc, arm64: add vmalloc tagging support for SW/HW_TAGS", v6.

This patchset adds vmalloc tagging support for SW_TAGS and HW_TAGS
KASAN modes.

About half of patches are cleanups I went for along the way.  None of them
seem to be important enough to go through stable, so I decided not to
split them out into separate patches/series.

The patchset is partially based on an early version of the HW_TAGS
patchset by Vincenzo that had vmalloc support.  Thus, I added a
Co-developed-by tag into a few patches.

SW_TAGS vmalloc tagging support is straightforward.  It reuses all of the
generic KASAN machinery, but uses shadow memory to store tags instead of
magic values.  Naturally, vmalloc tagging requires adding a few
kasan_reset_tag() annotations to the vmalloc code.

HW_TAGS vmalloc tagging support stands out.  HW_TAGS KASAN is based on Arm
MTE, which can only assigns tags to physical memory.  As a result, HW_TAGS
KASAN only tags vmalloc() allocations, which are backed by page_alloc
memory.  It ignores vmap() and others.

This patch (of 39):

Currently, should_skip_kasan_poison() has two definitions: one for when
CONFIG_DEFERRED_STRUCT_PAGE_INIT is enabled, one for when it's not.

Instead of duplicating the checks, add a deferred_pages_enabled() helper
and use it in a single should_skip_kasan_poison() definition.

Also move should_skip_kasan_poison() closer to its caller and clarify all
conditions in the comment.

Link: https://lkml.kernel.org/r/cover.1643047180.git.andreyknvl@google.com
Link: https://lkml.kernel.org/r/658b79f5fb305edaf7dc16bc52ea870d3220d4a8.1643047180.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: 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>
Cc: Will Deacon <will@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Collingbourne <pcc@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/migration: add trace events for base page and HugeTLB migrations

This adds two trace events for base page and HugeTLB page migrations.
These events, closely follow the implementation details like setting and
removing of PTE migration entries, which are essential operations for
migration.  The new CREATE_TRACE_POINTS in <mm/rmap.c> covers both
<events/migration.h> and <events/tlb.h> based trace events.  Hence drop
redundant CREATE_TRACE_POINTS from other places which could have otherwise
conflicted during build.

Link: https://lkml.kernel.org/r/1643368182-9588-3-git-send-email-anshuman.khandual@arm.com
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reported-by: kernel test robot <lkp@intel.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/migration: add trace events for THP migrations

Patch series "mm/migration: Add trace events", v3.

This adds trace events for all migration scenarios including base page,
THP and HugeTLB.

This patch (of 3):

This adds two trace events for PMD based THP migration without split.
These events closely follow the implementation details like setting and
removing of PMD migration entries, which are essential operations for THP
migration.  This moves CREATE_TRACE_POINTS into generic THP from powerpc
for these new trace events to be available on other platforms as well.

Link: https://lkml.kernel.org/r/1643368182-9588-1-git-send-email-anshuman.khandual@arm.com
Link: https://lkml.kernel.org/r/1643368182-9588-2-git-send-email-anshuman.khandual@arm.com
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/thp: fix NR_FILE_MAPPED accounting in page_*_file_rmap()

NR_FILE_MAPPED accounting in mm/rmap.c (for /proc/meminfo "Mapped" and
/proc/vmstat "nr_mapped" and the memcg's memory.stat "mapped_file") is
slightly flawed for file or shmem huge pages.

It is well thought out, and looks convincing, but there's a racy case when
the careful counting in page_remove_file_rmap() (without page lock) gets
discarded.  So that in a workload like two "make -j20" kernel builds under
memory pressure, with cc1 on hugepage text, "Mapped" can easily grow by a
spurious 5MB or more on each iteration, ending up implausibly bigger than
most other numbers in /proc/meminfo.  And, hypothetically, might grow to
the point of seriously interfering in mm/vmscan.c's heuristics, which do
take NR_FILE_MAPPED into some consideration.

Fixed by moving the __mod_lruvec_page_state() down to where it will not be
missed before return (and I've grown a bit tired of that oft-repeated
but-not-everywhere comment on the __ness: it gets lost in the move here).

Does page_add_file_rmap() need the same change?  I suspect not, because
page lock is held in all relevant cases, and its skipping case looks safe;
but it's much easier to be sure, if we do make the same change.

Link: https://lkml.kernel.org/r/e02e52a1-8550-a57c-ed29-f51191ea2375@google.com
Fixes: dd78fedde4b9 ("rmap: support file thp")
Signed-off-by: Hugh Dickins <hughd@google.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: filemap_unaccount_folio() large skip mapcount fixup

The page_mapcount_reset() when folio_mapped() while mapping_exiting() was
devised long before there were huge or compound pages in the cache.  It is
still valid for small pages, but not at all clear what's right to check
and reset on large pages.  Just don't try when folio_test_large().

Link: https://lkml.kernel.org/r/879c4426-4122-da9c-1a86-697f2c9a083@google.com
Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: delete __ClearPageWaiters()

The PG_waiters bit is not included in PAGE_FLAGS_CHECK_AT_FREE, and
vmscan.c's free_unref_page_list() callers rely on that not to generate
bad_page() alerts.  So __page_cache_release(), put_pages_list() and
release_pages() (and presumably copy-and-pasted free_zone_device_page())
are redundant and misleading to make a special point of clearing it (as
the "__" implies, it could only safely be used on the freeing path).

Delete __ClearPageWaiters().  Remark on this in one of the "possible"
comments in folio_wake_bit(), and delete the superfluous comments.

Link: https://lkml.kernel.org/r/3eafa969-5b1a-accf-88fe-318784c791a@google.com
Signed-off-by: Hugh Dickins <hughd@google.com>
Tested-by: Yu Zhao <yuzhao@google.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Yu Zhao <yuzhao@google.com>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

selftest/vm: add helpers to detect PAGE_SIZE and PAGE_SHIFT

PAGE_SIZE is not 4096 in many configurations, particularly ppc64 uses 64K
pages in majority of cases.

Add helpers to detect PAGE_SIZE and PAGE_SHIFT dynamically.

Without this tests are broken w.r.t reading /proc/self/pagemap

    if (pread(pagemap_fd, ent, sizeof(ent),
              (uintptr_t)ptr >> (PAGE_SHIFT - 3)) != sizeof(ent))
              err(2, "read pagemap");

Link: https://lkml.kernel.org/r/20220307054355.149820-2-aneesh.kumar@linux.ibm.com
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

selftest/vm: add util.h and and move helper functions there

Avoid code duplication by adding util.h.  No functional change in this
patch.

Link: https://lkml.kernel.org/r/20220307054355.149820-1-aneesh.kumar@linux.ibm.com
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: unexport page_init_poison

page_init_poison is only used in core MM code, so unexport it.

Link: https://lkml.kernel.org/r/20220207063446.1833404-1-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

tools/vm/page_owner_sort.c: support for user-defined culling rules

When viewing page owner information, we may want to cull blocks of
information with our own rules.  So it is important to enhance culling
function to provide the support for customizing culling rules.
Therefore, following adjustments are made:

1. Add --cull option to support the culling of blocks of information
   with user-defined culling rules.

./page_owner_sort <input> <output> --cull=<rules>
./page_owner_sort <input> <output> --cull <rules>

  <rules> is a single argument in the form of a comma-separated list to
  specify individual culling rules, by the sequence of keys k1,k2, ....
  Mixed use of abbreviated and complete-form of keys is allowed.

  For reference, please see the document(Documentation/vm/page_owner.rst).

Now, assuming two blocks in the input file are as follows:

Page allocated via order 0, mask xxxx, pid 1, tgid 1 (task_name_demo)
PFN xxxx
 prep_new_page+0xd0/0xf8
 get_page_from_freelist+0x4a0/0x1290
 __alloc_pages+0x168/0x340
 alloc_pages+0xb0/0x158

Page allocated via order 0, mask xxxx, pid 32, tgid 32 (task_name_demo)
PFN xxxx
 prep_new_page+0xd0/0xf8
 get_page_from_freelist+0x4a0/0x1290
 __alloc_pages+0x168/0x340
 alloc_pages+0xb0/0x158

If we want to cull the blocks by stacktrace and task command name, we can
use this command:

./page_owner_sort <input> <output> --cull=stacktrace,name

The output would be like:

2 times, 2 pages, task_comm_name: task_name_demo
 prep_new_page+0xd0/0xf8
 get_page_from_freelist+0x4a0/0x1290
 __alloc_pages+0x168/0x340
 alloc_pages+0xb0/0x158

As we can see, these two blocks are culled successfully, for they share
the same pid and task command name.

However, if we want to cull the blocks by pid, stacktrace and task command
name, we can this command:

./page_owner_sort <input> <output> --cull=stacktrace,name,pid

The output would be like:

1 times, 1 pages, PID 1, task_comm_name: task_name_demo
 prep_new_page+0xd0/0xf8
 get_page_from_freelist+0x4a0/0x1290
 __alloc_pages+0x168/0x340
 alloc_pages+0xb0/0x158

1 times, 1 pages, PID 32, task_comm_name: task_name_demo
 prep_new_page+0xd0/0xf8
 get_page_from_freelist+0x4a0/0x1290
 __alloc_pages+0x168/0x340
 alloc_pages+0xb0/0x158

As we can see, these two blocks are failed to cull, for their PIDs are
different.

2. Add explanations of --cull options to the document.

This work is coauthored by
Yixuan Cao
Shenghong Han
Yinan Zhang
Chongxi Zhao
Yuhong Feng

Link: https://lkml.kernel.org/r/20220312145834.624-1-yejiajian2018@email.szu.edu.cn
Signed-off-by: Jiajian Ye <yejiajian2018@email.szu.edu.cn>
Cc: Yixuan Cao <caoyixuan2019@email.szu.edu.cn>
Cc: Shenghong Han <hanshenghong2019@email.szu.edu.cn>
Cc: Yinan Zhang <zhangyinan2019@email.szu.edu.cn>
Cc: Chongxi Zhao <zhaochongxi2019@email.szu.edu.cn>
Cc: Yuhong Feng <yuhongf@szu.edu.cn>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Sean Anderson <seanga2@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

tools/vm/page_owner_sort.c: support for selecting by PID, TGID or task command name

When viewing page owner information, we may also need to select the blocks
by PID, TGID or task command name, which helps to get more accurate page
allocation information as needed.

Therefore, following adjustments are made:

1. Add three new options, including --pid, --tgid and --name, to support
   the selection of information blocks by a specific pid, tgid and task
   command name. In addtion, multiple options are allowed to be used at
   the same time.

./page_owner_sort [input] [output] --pid <PID>
./page_owner_sort [input] [output] --tgid <TGID>
./page_owner_sort [input] [output] --name <TASK_COMMAND_NAME>

   Assuming a scenario when a multi-threaded program, ./demo (PID =
   5280), is running, and ./demo creates a child process (PID = 5281).

$ps
PID   TTY        TIME   CMD
5215  pts/0    00:00:00  bash
5280  pts/0    00:00:00  ./demo
5281  pts/0    00:00:00  ./demo
5282  pts/0    00:00:00  ps

   It would be better to filter out the records with tgid=5280 and the
   task name "demo" when debugging the parent process, and the specific
   usage is

./page_owner_sort [input] [output] --tgid 5280 --name demo

2. Add explanations of three new options, including --pid, --tgid and
   --name, to the document.

This work is coauthored by
Shenghong Han <hanshenghong2019@email.szu.edu.cn>,
Yixuan Cao <caoyixuan2019@email.szu.edu.cn>,
Yinan Zhang <zhangyinan2019@email.szu.edu.cn>,
Chongxi Zhao <zhaochongxi2019@email.szu.edu.cn>,
Yuhong Feng <yuhongf@szu.edu.cn>.

Link: https://lkml.kernel.org/r/1646835223-7584-1-git-send-email-yejiajian2018@email.szu.edu.cn
Signed-off-by: Jiajian Ye <yejiajian2018@email.szu.edu.cn>
Cc: Sean Anderson <seanga2@gmail.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Zhenliang Wei <weizhenliang@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

tools/vm/page_owner_sort: support for sorting by task command name

When viewing page owner information, we may also need to the block to be
sorted by task command name.  Therefore, the following adjustments are
made:

1. Add a member variable to record task command name of block.

2. Add a new -n option to sort the information of blocks by task command
   name.

3. Add -n option explanation in the document.

Link: https://lkml.kernel.org/r/20220306030640.43054-2-yejiajian2018@email.szu.edu.cn
Signed-off-by: Jiajian Ye <yejiajian2018@email.szu.edu.cn>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Sean Anderson <seanga2@gmail.com>
Cc: Yixuan Cao <caoyixuan2019@email.szu.edu.cn>
Cc: Zhenliang Wei <weizhenliang@huawei.com>
Cc: <zhaochongxi2019@email.szu.edu.cn>
Cc: <hanshenghong2019@email.szu.edu.cn>
Cc: <zhangyinan2019@email.szu.edu.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

tools/vm/page_owner_sort: fix three trivival places

The following adjustments are made:

1. Instead of using another array to cull the blocks after sorting,
   reuse the old array.  So there is no need to malloc a new array.

2. When enabling '-f' option to filter out the blocks which have been
   released, only add those have not been released in the list, rather
   than add all of blocks in the list and then do the filtering when
   printing the result.

3. When enabling '-c' option to cull the blocks by comparing
   stacktrace, print the stacetrace rather than the total block.

Link: https://lkml.kernel.org/r/20220306030640.43054-1-yejiajian2018@email.szu.edu.cn
Signed-off-by: Jiajian Ye <yejiajian2018@email.szu.edu.cn>
Cc: <hanshenghong2019@email.szu.edu.cn>
Cc: Sean Anderson <seanga2@gmail.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Yixuan Cao <caoyixuan2019@email.szu.edu.cn>
Cc: <zhangyinan2019@email.szu.edu.cn>
Cc: Zhenliang Wei <weizhenliang@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

tools/vm/page_owner_sort.c: support sorting by tgid and update documentation

When the "page owner" information is read, the information sorted
by TGID is expected.

As a result, the following adjustments have been made:

1. Add a new -P option to sort the information of blocks by TGID in
   ascending order.

2. Adjust the order of member variables in block_list strust to avoid
   one 4 byte hole.

3. Add -P option explanation in the document.

Link: https://lkml.kernel.org/r/20220301151438.166118-3-yejiajian2018@email.szu.edu.cn
Signed-off-by: Jiajian Ye <yejiajian2018@email.szu.edu.cn>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Yixuan Cao <caoyixuan2019@email.szu.edu.cn>
Cc: Zhenliang Wei <weizhenliang@huawei.com>
Cc: Yinan Zhang <zhangyinan2019@email.szu.edu.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

tools/vm/page_owner_sort.c: add a security check

Add a security check after using malloc() to allocate memory.

Link: https://lkml.kernel.org/r/20220301151438.166118-2-yejiajian2018@email.szu.edu.cn
Signed-off-by: Jiajian Ye <yejiajian2018@email.szu.edu.cn>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Yinan Zhang <zhangyinan2019@email.szu.edu.cn>
Cc: Yixuan Cao <caoyixuan2019@email.szu.edu.cn>
Cc: Zhenliang Wei <weizhenliang@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

tools/vm/page_owner_sort.c: fix comments

Two adjustments are made:

1. Correct a grammatical error: replace the "what" in "Do the job what
   you want to debug" with "that".

2. Replace "has not been" with "has been" in the description of the -f
   option: According to Commit b1c9ba071e7d ("tools/vm/page_owner_sort.c:
   fix the instructions for use"), the description of the "-f" option is
   "Filter out the information of blocks whose memory has been released."

Link: https://lkml.kernel.org/r/20220301151438.166118-1-yejiajian2018@email.szu.edu.cn
Signed-off-by: Jiajian Ye <yejiajian2018@email.szu.edu.cn>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Yinan Zhang <zhangyinan2019@email.szu.edu.cn>
Cc: Yixuan Cao <caoyixuan2019@email.szu.edu.cn>
Cc: Zhenliang Wei <weizhenliang@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

tools/vm/page_owner_sort.c: fix the instructions for use

I noticed a discrepancy between the usage method and the code logic.

If we enable the -f option, it should be "Filter out the information of
blocks whose memory has been released".

Link: https://lkml.kernel.org/r/20220219143106.2805-1-caoyixuan2019@email.szu.edu.cn
Signed-off-by: Yixuan Cao <caoyixuan2019@email.szu.edu.cn>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Sean Anderson <seanga2@gmail.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Zhenliang Wei <weizhenliang@huawei.com>
Cc: Tang Bin <tangbin@cmss.chinamobile.com>
Cc: Yinan Zhang <zhangyinan2019@email.szu.edu.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/page_owner.c: record tgid

In a single-threaded process, the pid in kernel task_struct is the same
as the tgid, which can mark the process of page allocation.  But in a
multithreaded process, only the task_struct of the thread leader has the
same pid as tgid, and the pids of other threads are different from tgid.
Therefore, tgid is recorded to provide effective information for
debugging and data statistics of multithreaded programs.

This can also be achieved by observing the task name (executable file
name) for a specific process.  However, when the same program is started
multiple times, the task name is the same and the tgid is different.
Therefore, in the debugging of multi-threaded programs, combined with
the task name and tgid, more accurate runtime information of a certain
run of the program can be obtained.

Link: https://lkml.kernel.org/r/20220219180450.2399-1-caoyixuan2019@email.szu.edu.cn
Signed-off-by: Yixuan Cao <caoyixuan2019@email.szu.edu.cn>
Cc: Waiman Long <longman@redhat.com>
Cc: Rafael Aquini <aquini@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/page_owner: record task command name

The page_owner information currently includes the pid of the calling
task.  That is useful as long as the task is still running.  Otherwise,
the number is meaningless.  To have more information about the
allocating tasks that had exited by the time the page_owner information
is retrieved, we need to store the command name of the task.

Add a new comm field into page_owner structure to store the command name
and display it when the page_owner information is retrieved.

Link: https://lkml.kernel.org/r/20220202203036.744010-5-longman@redhat.com
Signed-off-by: Waiman Long <longman@redhat.com>
Acked-by: Rafael Aquini <aquini@redhat.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/page_owner: print memcg information

It was found that a number of offline memcgs were not freed because they
were pinned by some charged pages that were present.  Even "echo 1 >
/proc/sys/vm/drop_caches" wasn't able to free those pages.  These
offline but not freed memcgs tend to increase in number over time with
the side effect that percpu memory consumption as shown in /proc/meminfo
also increases over time.

In order to find out more information about those pages that pin offline
memcgs, the page_owner feature is extended to print memory cgroup
information especially whether the cgroup is offline or not.  RCU read
lock is taken when memcg is being accessed to make sure that it won't be
freed.

Link: https://lkml.kernel.org/r/20220202203036.744010-4-longman@redhat.com
Signed-off-by: Waiman Long <longman@redhat.com>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Roman Gushchin <guro@fb.com>
Acked-by: Rafael Aquini <aquini@redhat.com>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/page_owner: use scnprintf() to avoid excessive buffer overrun check

The snprintf() function can return a length greater than the given input
size.  That will require a check for buffer overrun after each
invocation of snprintf().  scnprintf(), on the other hand, will never
return a greater length.

By using scnprintf() in selected places, we can avoid some buffer
overrun checks except after stack_depot_snprint() and after the last
snprintf().

Link: https://lkml.kernel.org/r/20220202203036.744010-3-longman@redhat.com
Signed-off-by: Waiman Long <longman@redhat.com>
Acked-by: David Rientjes <rientjes@google.com>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Acked-by: Rafael Aquini <aquini@redhat.com>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib/vsprintf: avoid redundant work with 0 size

Patch series "mm/page_owner: Extend page_owner to show memcg information", v4.

While debugging the constant increase in percpu memory consumption on a
system that spawned large number of containers, it was found that a lot
of offline mem_cgroup structures remained in place without being freed.
Further investigation indicated that those mem_cgroup structures were
pinned by some pages.

In order to find out what those pages are, the existing page_owner
debugging tool is extended to show memory cgroup information and whether
those memcgs are offline or not.  With the enhanced page_owner tool, the
following is a typical page that pinned the mem_cgroup structure in my
test case:

  Page allocated via order 0, mask 0x1100cca(GFP_HIGHUSER_MOVABLE), pid 162970 (podman), ts 1097761405537 ns, free_ts 1097760838089 ns
  PFN 1925700 type Movable Block 3761 type Movable Flags 0x17ffffc00c001c(uptodate|dirty|lru|reclaim|swapbacked|node=0|zone=2|lastcpupid=0x1fffff)
    prep_new_page+0xac/0xe0
    get_page_from_freelist+0x1327/0x14d0
    __alloc_pages+0x191/0x340
    alloc_pages_vma+0x84/0x250
    shmem_alloc_page+0x3f/0x90
    shmem_alloc_and_acct_page+0x76/0x1c0
    shmem_getpage_gfp+0x281/0x940
    shmem_write_begin+0x36/0xe0
    generic_perform_write+0xed/0x1d0
    __generic_file_write_iter+0xdc/0x1b0
    generic_file_write_iter+0x5d/0xb0
    new_sync_write+0x11f/0x1b0
    vfs_write+0x1ba/0x2a0
    ksys_write+0x59/0xd0
    do_syscall_64+0x37/0x80
    entry_SYSCALL_64_after_hwframe+0x44/0xae
  Charged to offline memcg libpod-conmon-15e4f9c758422306b73b2dd99f9d50a5ea53cbb16b4a13a2c2308a4253cc0ec8.

So the page was not freed because it was part of a shmem segment.  That
is useful information that can help users to diagnose similar problems.

With cgroup v1, /proc/cgroups can be read to find out the total number
of memory cgroups (online + offline).  With cgroup v2, the cgroup.stat
of the root cgroup can be read to find the number of dying cgroups (most
likely pinned by dying memcgs).

The page_owner feature is not supposed to be enabled for production
system due to its memory overhead.  However, if it is suspected that
dying memcgs are increasing over time, a test environment with
page_owner enabled can then be set up with appropriate workload for
further analysis on what may be causing the increasing number of dying
memcgs.

This patch (of 4):

For *scnprintf(), vsnprintf() is always called even if the input size is
0.  That is a waste of time, so just return 0 in this case.

Note that vsnprintf() will never return -1 to indicate an error.  So
skipping the call to vsnprintf() when size is 0 will have no functional
impact at all.

Link: https://lkml.kernel.org/r/20220202203036.744010-1-longman@redhat.com
Link: https://lkml.kernel.org/r/20220202203036.744010-2-longman@redhat.com
Signed-off-by: Waiman Long <longman@redhat.com>
Acked-by: David Rientjes <rientjes@google.com>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Acked-by: Roman Gushchin <guro@fb.com>
Acked-by: Rafael Aquini <aquini@redhat.com>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Documentation/vm/page_owner.rst: fix unexpected indentation warns

Fix Unexpected indentation warns in page_owner:

  Documentation/vm/page_owner.rst:92: WARNING: Unexpected indentation.
  Documentation/vm/page_owner.rst:96: WARNING: Unexpected indentation.
  Documentation/vm/page_owner.rst:107: WARNING: Unexpected indentation.

Link: https://lkml.kernel.org/r/20211215001929.47866-1-skhan@linuxfoundation.org
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Documentation/vm/page_owner.rst: update the documentation

Update the documentation of ``page_owner``.

[akpm@linux-foundation.org: small grammatical tweaks]

Link: https://lkml.kernel.org/r/20211214134736.2569-1-hanshenghong2019@email.szu.edu.cn
Signed-off-by: Shenghong Han <hanshenghong2019@email.szu.edu.cn>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Georgi Djakov <georgi.djakov@linaro.org>
Cc: Liam Mark <lmark@codeaurora.org>
Cc: Tang Bin <tangbin@cmss.chinamobile.com>
Cc: Zhang Shengju <zhangshengju@cmss.chinamobile.com>
Cc: Zhenliang Wei <weizhenliang@huawei.com>
Cc: Xiaoming Ni <nixiaoming@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

tools/vm/page_owner_sort.c: delete invalid duplicate code

I noticed that there is two invalid lines of duplicate code.  It's better
to delete it.

Link: https://lkml.kernel.org/r/20211213095743.3630-1-caoyixuan2019@email.szu.edu.cn
Signed-off-by: Yixuan Cao <caoyixuan2019@email.szu.edu.cn>
Cc: Mark Brown <broonie@kernel.org>
Cc: Sean Anderson <seanga2@gmail.com>
Cc: Zhenliang Wei <weizhenliang@huawei.com>
Cc: Tang Bin <tangbin@cmss.chinamobile.com>
Cc: Yinan Zhang <zhangyinan2019@email.szu.edu.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

tools/vm/page_owner_sort.c: two trivial fixes

1) There is an unused variable. It's better to delete it.
2) One case is missing in the usage().

Link: https://lkml.kernel.org/r/20211213164518.2461-1-hanshenghong2019@email.szu.edu.cn
Signed-off-by: Shenghong Han <hanshenghong2019@email.szu.edu.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

tools/vm/page_owner_sort.c: support sorting pid and time

When viewing the page owner information, we expect that the information
can be sorted by PID, so that we can quickly combine PID with the program
to check the information together.

We also expect that the information can be sorted by time.  Time sorting
helps to view the running status of the program according to the time
interval when the program hangs up.

Finally, we hope to pass the page_ owner_ Sort.  C can reduce part of the
output and only output the plate information whose memory has not been
released, which can make us locate the problem of the program faster.
Therefore, the following adjustments have been made:

1. Add the static functions search_pattern and check_regcomp to
   improve the cleanliness.

2. Add member attributes and their corresponding sorting methods.  In
   terms of comparison time, int will overflow because the data of ull is
   too large, so the ternary operator is used

3. Add the -f parameter to filter out the information of blocks whose
   memory has not been released

Link: https://lkml.kernel.org/r/20211206165653.5093-1-zhaochongxi2019@email.szu.edu.cn
Signed-off-by: Chongxi Zhao <zhaochongxi2019@email.szu.edu.cn>
Reviewed-by: Sean Anderson <seanga2@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

tools/vm/page_owner_sort.c: add switch between culling by stacktrace and txt

Culling by comparing stacktrace would casue loss of some information.  For
example, if there exists 2 blocks which have the same stacktrace and the
different head info

  Page allocated via order 0, mask 0x108c48(...), pid 73696,
    ts 1578829190639010 ns, free_ts 1576583851324450 ns
    prep_new_page+0x80/0xb8
    get_page_from_freelist+0x924/0xee8
    __alloc_pages+0x138/0xc18
    alloc_pages+0x80/0xf0
    __page_cache_alloc+0x90/0xc8

  Page allocated via order 0, mask 0x108c48(...), pid 61806,
    ts 1354113726046100 ns, free_ts 1354104926841400 ns
    prep_new_page+0x80/0xb8
    get_page_from_freelist+0x924/0xee8
    __alloc_pages+0x138/0xc18
    alloc_pages+0x80/0xf0
    __page_cache_alloc+0x90/0xc8

After culling, it would be like this

  2 times, 2 pages:
  Page allocated via order 0, mask 0x108c48(...), pid 73696,
    ts 1578829190639010 ns, free_ts 1576583851324450 ns
    prep_new_page+0x80/0xb8
    get_page_from_freelist+0x924/0xee8
    __alloc_pages+0x138/0xc18
    alloc_pages+0x80/0xf0
    __page_cache_alloc+0x90/0xc8

The info of second block missed.  So, add -c to turn on culling by
stacktrace.  By default, it will cull by txt.

Link: https://lkml.kernel.org/r/20211129145658.2491-1-zhangyinan2019@email.szu.edu.cn
Signed-off-by: Yinan Zhang <zhangyinan2019@email.szu.edu.cn>
Cc: Changhee Han <ch0.han@lge.com>
Cc: Sean Anderson <seanga2@gmail.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Tang Bin <tangbin@cmss.chinamobile.com>
Cc: Zhang Shengju <zhangshengju@cmss.chinamobile.com>
Cc: Zhenliang Wei <weizhenliang@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

tools/vm/page_owner_sort.c: support sorting by stack trace

This adds the ability to sort by stacktraces.  This is helpful when
comparing multiple dumps of page_owner taken at different times, since
blocks will not be reordered if they were allocated/free'd.

Link: https://lkml.kernel.org/r/20211124193709.1805776-2-seanga2@gmail.com
Signed-off-by: Sean Anderson <seanga2@gmail.com>
Cc: Zhenliang Wei <weizhenliang@huawei.com>
Cc: Changhee Han <ch0.han@lge.com>
Cc: Tang Bin <tangbin@cmss.chinamobile.com>
Cc: Zhang Shengju <zhangshengju@cmss.chinamobile.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Yinan Zhang <zhangyinan2019@email.szu.edu.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

tools/vm/page_owner_sort.c: sort by stacktrace before culling

The contents of page_owner have changed to include more information than
the stack trace.  On a modern kernel, the blocks look like

  Page allocated via order 0, mask 0x0(), pid 1, ts 165564237 ns, free_ts 0 ns
    register_early_stack+0x4b/0x90
    init_page_owner+0x39/0x250
    kernel_init_freeable+0x11e/0x242
    kernel_init+0x16/0x130

Sorting by the contents of .txt will result in almost no repeated pages,
as the pid, ts, and free_ts will almost never be the same.  Instead,
sort by the contents of the stack trace, which we assume to be whatever
is after the first line.

[seanga2@gmail.com: fix NULL-pointer dereference when comparing stack traces]
Link: https://lkml.kernel.org/r/20211125162653.1855958-1-seanga2@gmail.com
Link: https://lkml.kernel.org/r/20211124193709.1805776-1-seanga2@gmail.com
Signed-off-by: Sean Anderson <seanga2@gmail.com>
Cc: Changhee Han <ch0.han@lge.com>
Cc: Tang Bin <tangbin@cmss.chinamobile.com>
Cc: Zhang Shengju <zhangshengju@cmss.chinamobile.com>
Cc: Zhenliang Wei <weizhenliang@huawei.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Yinan Zhang <zhangyinan2019@email.szu.edu.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Merge branch 'akpm' (patches from Andrew)

Merge more updates from Andrew Morton:
 "Various misc subsystems, before getting into the post-linux-next
  material.

  41 patches.

  Subsystems affected by this patch series: procfs, misc, core-kernel,
  lib, checkpatch, init, pipe, minix, fat, cgroups, kexec, kdump,
  taskstats, panic, kcov, resource, and ubsan"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (41 commits)
  Revert "ubsan, kcsan: Don't combine sanitizer with kcov on clang"
  kernel/resource: fix kfree() of bootmem memory again
  kcov: properly handle subsequent mmap calls
  kcov: split ioctl handling into locked and unlocked parts
  panic: move panic_print before kmsg dumpers
  panic: add option to dump all CPUs backtraces in panic_print
  docs: sysctl/kernel: add missing bit to panic_print
  taskstats: remove unneeded dead assignment
  kasan: no need to unset panic_on_warn in end_report()
  ubsan: no need to unset panic_on_warn in ubsan_epilogue()
  panic: unset panic_on_warn inside panic()
  docs: kdump: add scp example to write out the dump file
  docs: kdump: update description about sysfs file system support
  arm64: mm: use IS_ENABLED(CONFIG_KEXEC_CORE) instead of #ifdef
  x86/setup: use IS_ENABLED(CONFIG_KEXEC_CORE) instead of #ifdef
  riscv: mm: init: use IS_ENABLED(CONFIG_KEXEC_CORE) instead of #ifdef
  kexec: make crashk_res, crashk_low_res and crash_notes symbols always visible
  cgroup: use irqsave in cgroup_rstat_flush_locked().
  fat: use pointer to simple type in put_user()
  minix: fix bug when opening a file with O_DIRECT
  ...

Merge tag 'net-next-5.18' of git://git./linux/kernel/git/netdev/net-next

Pull networking updates from Jakub Kicinski:
 "The sprinkling of SPI drivers is because we added a new one and Mark
  sent us a SPI driver interface conversion pull request.

  Core
  ----

   - Introduce XDP multi-buffer support, allowing the use of XDP with
     jumbo frame MTUs and combination with Rx coalescing offloads (LRO).

   - Speed up netns dismantling (5x) and lower the memory cost a little.
     Remove unnecessary per-netns sockets. Scope some lists to a netns.
     Cut down RCU syncing. Use batch methods. Allow netdev registration
     to complete out of order.

   - Support distinguishing timestamp types (ingress vs egress) and
     maintaining them across packet scrubbing points (e.g. redirect).

   - Continue the work of annotating packet drop reasons throughout the
     stack.

   - Switch netdev error counters from an atomic to dynamically
     allocated per-CPU counters.

   - Rework a few preempt_disable(), local_irq_save() and busy waiting
     sections problematic on PREEMPT_RT.

   - Extend the ref_tracker to allow catching use-after-free bugs.

  BPF
  ---

   - Introduce "packing allocator" for BPF JIT images. JITed code is
     marked read only, and used to be allocated at page granularity.
     Custom allocator allows for more efficient memory use, lower iTLB
     pressure and prevents identity mapping huge pages from getting
     split.

   - Make use of BTF type annotations (e.g. __user, __percpu) to enforce
     the correct probe read access method, add appropriate helpers.

   - Convert the BPF preload to use light skeleton and drop the
     user-mode-driver dependency.

   - Allow XDP BPF_PROG_RUN test infra to send real packets, enabling
     its use as a packet generator.

   - Allow local storage memory to be allocated with GFP_KERNEL if
     called from a hook allowed to sleep.

   - Introduce fprobe (multi kprobe) to speed up mass attachment (arch
     bits to come later).

   - Add unstable conntrack lookup helpers for BPF by using the BPF
     kfunc infra.

   - Allow cgroup BPF progs to return custom errors to user space.

   - Add support for AF_UNIX iterator batching.

   - Allow iterator programs to use sleepable helpers.

   - Support JIT of add, and, or, xor and xchg atomic ops on arm64.

   - Add BTFGen support to bpftool which allows to use CO-RE in kernels
     without BTF info.

   - Large number of libbpf API improvements, cleanups and deprecations.

  Protocols
  ---------

   - Micro-optimize UDPv6 Tx, gaining up to 5% in test on dummy netdev.

   - Adjust TSO packet sizes based on min_rtt, allowing very low latency
     links (data centers) to always send full-sized TSO super-frames.

   - Make IPv6 flow label changes (AKA hash rethink) more configurable,
     via sysctl and setsockopt. Distinguish between server and client
     behavior.

   - VxLAN support to "collect metadata" devices to terminate only
     configured VNIs. This is similar to VLAN filtering in the bridge.

   - Support inserting IPv6 IOAM information to a fraction of frames.

   - Add protocol attribute to IP addresses to allow identifying where
     given address comes from (kernel-generated, DHCP etc.)

   - Support setting socket and IPv6 options via cmsg on ping6 sockets.

   - Reject mis-use of ECN bits in IP headers as part of DSCP/TOS.
     Define dscp_t and stop taking ECN bits into account in fib-rules.

   - Add support for locked bridge ports (for 802.1X).

   - tun: support NAPI for packets received from batched XDP buffs,
     doubling the performance in some scenarios.

   - IPv6 extension header handling in Open vSwitch.

   - Support IPv6 control message load balancing in bonding, prevent
     neighbor solicitation and advertisement from using the wrong port.
     Support NS/NA monitor selection similar to existing ARP monitor.

   - SMC
      - improve performance with TCP_CORK and sendfile()
      - support auto-corking
      - support TCP_NODELAY

   - MCTP (Management Component Transport Protocol)
      - add user space tag control interface
      - I2C binding driver (as specified by DMTF DSP0237)

   - Multi-BSSID beacon handling in AP mode for WiFi.

   - Bluetooth:
      - handle MSFT Monitor Device Event
      - add MGMT Adv Monitor Device Found/Lost events

   - Multi-Path TCP:
      - add support for the SO_SNDTIMEO socket option
      - lots of selftest cleanups and improvements

   - Increase the max PDU size in CAN ISOTP to 64 kB.

  Driver API
  ----------

   - Add HW counters for SW netdevs, a mechanism for devices which
     offload packet forwarding to report packet statistics back to
     software interfaces such as tunnels.

   - Select the default NIC queue count as a fraction of number of
     physical CPU cores, instead of hard-coding to 8.

   - Expose devlink instance locks to drivers. Allow device layer of
     drivers to use that lock directly instead of creating their own
     which always runs into ordering issues in devlink callbacks.

   - Add header/data split indication to guide user space enabling of
     TCP zero-copy Rx.

   - Allow configuring completion queue event size.

   - Refactor page_pool to enable fragmenting after allocation.

   - Add allocation and page reuse statistics to page_pool.

   - Improve Multiple Spanning Trees support in the bridge to allow
     reuse of topologies across VLANs, saving HW resources in switches.

   - DSA (Distributed Switch Architecture):
      - replay and offload of host VLAN entries
      - offload of static and local FDB entries on LAG interfaces
      - FDB isolation and unicast filtering

  New hardware / drivers
  ----------------------

   - Ethernet:
      - LAN937x T1 PHYs
      - Davicom DM9051 SPI NIC driver
      - Realtek RTL8367S, RTL8367RB-VB switch and MDIO
      - Microchip ksz8563 switches
      - Netronome NFP3800 SmartNICs
      - Fungible SmartNICs
      - MediaTek MT8195 switches

   - WiFi:
      - mt76: MediaTek mt7916
      - mt76: MediaTek mt7921u USB adapters
      - brcmfmac: Broadcom BCM43454/6

   - Mobile:
      - iosm: Intel M.2 7360 WWAN card

  Drivers
  -------

   - Convert many drivers to the new phylink API built for split PCS
     designs but also simplifying other cases.

   - Intel Ethernet NICs:
      - add TTY for GNSS module for E810T device
      - improve AF_XDP performance
      - GTP-C and GTP-U filter offload
      - QinQ VLAN support

   - Mellanox Ethernet NICs (mlx5):
      - support xdp->data_meta
      - multi-buffer XDP
      - offload tc push_eth and pop_eth actions

   - Netronome Ethernet NICs (nfp):
      - flow-independent tc action hardware offload (police / meter)
      - AF_XDP

   - Other Ethernet NICs:
      - at803x: fiber and SFP support
      - xgmac: mdio: preamble suppression and custom MDC frequencies
      - r8169: enable ASPM L1.2 if system vendor flags it as safe
      - macb/gem: ZynqMP SGMII
      - hns3: add TX push mode
      - dpaa2-eth: software TSO
      - lan743x: multi-queue, mdio, SGMII, PTP
      - axienet: NAPI and GRO support

   - Mellanox Ethernet switches (mlxsw):
      - source and dest IP address rewrites
      - RJ45 ports

   - Marvell Ethernet switches (prestera):
      - basic routing offload
      - multi-chain TC ACL offload

   - NXP embedded Ethernet switches (ocelot & felix):
      - PTP over UDP with the ocelot-8021q DSA tagging protocol
      - basic QoS classification on Felix DSA switch using dcbnl
      - port mirroring for ocelot switches

   - Microchip high-speed industrial Ethernet (sparx5):
      - offloading of bridge port flooding flags
      - PTP Hardware Clock

   - Other embedded switches:
      - lan966x: PTP Hardward Clock
      - qca8k: mdio read/write operations via crafted Ethernet packets

   - Qualcomm 802.11ax WiFi (ath11k):
      - add LDPC FEC type and 802.11ax High Efficiency data in radiotap
      - enable RX PPDU stats in monitor co-exist mode

   - Intel WiFi (iwlwifi):
      - UHB TAS enablement via BIOS
      - band disablement via BIOS
      - channel switch offload
      - 32 Rx AMPDU sessions in newer devices

   - MediaTek WiFi (mt76):
      - background radar detection
      - thermal management improvements on mt7915
      - SAR support for more mt76 platforms
      - MBSSID and 6 GHz band on mt7915

   - RealTek WiFi:
      - rtw89: AP mode
      - rtw89: 160 MHz channels and 6 GHz band
      - rtw89: hardware scan

   - Bluetooth:
      - mt7921s: wake on Bluetooth, SCO over I2S, wide-band-speed (WBS)

   - Microchip CAN (mcp251xfd):
      - multiple RX-FIFOs and runtime configurable RX/TX rings
      - internal PLL, runtime PM handling simplification
      - improve chip detection and error handling after wakeup"

* tag 'net-next-5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (2521 commits)
  llc: fix netdevice reference leaks in llc_ui_bind()
  drivers: ethernet: cpsw: fix panic when interrupt coaleceing is set via ethtool
  ice: don't allow to run ice_send_event_to_aux() in atomic ctx
  ice: fix 'scheduling while atomic' on aux critical err interrupt
  net/sched: fix incorrect vlan_push_eth dest field
  net: bridge: mst: Restrict info size queries to bridge ports
  net: marvell: prestera: add missing destroy_workqueue() in prestera_module_init()
  drivers: net: xgene: Fix regression in CRC stripping
  net: geneve: add missing netlink policy and size for IFLA_GENEVE_INNER_PROTO_INHERIT
  net: dsa: fix missing host-filtered multicast addresses
  net/mlx5e: Fix build warning, detected write beyond size of field
  iwlwifi: mvm: Don't fail if PPAG isn't supported
  selftests/bpf: Fix kprobe_multi test.
  Revert "rethook: x86: Add rethook x86 implementation"
  Revert "arm64: rethook: Add arm64 rethook implementation"
  Revert "powerpc: Add rethook support"
  Revert "ARM: rethook: Add rethook arm implementation"
  netdevice: add missing dm_private kdoc
  net: bridge: mst: prevent NULL deref in br_mst_info_size()
  selftests: forwarding: Use same VRF for port and VLAN upper
  ...

Merge tag 'vfio-v5.18-rc1' of https://github.com/awilliam/linux-vfio

Pull VFIO updates from Alex Williamson:

 - Introduce new device migration uAPI and implement device specific
   mlx5 vfio-pci variant driver supporting new protocol (Jason
   Gunthorpe, Yishai Hadas, Leon Romanovsky)

 - New HiSilicon acc vfio-pci variant driver, also supporting migration
   interface (Shameer Kolothum, Longfang Liu)

 - D3hot fixes for vfio-pci-core (Abhishek Sahu)

 - Document new vfio-pci variant driver acceptance criteria
   (Alex Williamson)

 - Fix UML build unresolved ioport_{un}map() functions
   (Alex Williamson)

 - Fix MAINTAINERS due to header movement (Lukas Bulwahn)

* tag 'vfio-v5.18-rc1' of https://github.com/awilliam/linux-vfio: (31 commits)
  vfio-pci: Provide reviewers and acceptance criteria for variant drivers
  MAINTAINERS: adjust entry for header movement in hisilicon qm driver
  hisi_acc_vfio_pci: Use its own PCI reset_done error handler
  hisi_acc_vfio_pci: Add support for VFIO live migration
  crypto: hisilicon/qm: Set the VF QM state register
  hisi_acc_vfio_pci: Add helper to retrieve the struct pci_driver
  hisi_acc_vfio_pci: Restrict access to VF dev BAR2 migration region
  hisi_acc_vfio_pci: add new vfio_pci driver for HiSilicon ACC devices
  hisi_acc_qm: Move VF PCI device IDs to common header
  crypto: hisilicon/qm: Move few definitions to common header
  crypto: hisilicon/qm: Move the QM header to include/linux
  vfio/mlx5: Fix to not use 0 as NULL pointer
  PCI/IOV: Fix wrong kernel-doc identifier
  vfio/mlx5: Use its own PCI reset_done error handler
  vfio/pci: Expose vfio_pci_core_aer_err_detected()
  vfio/mlx5: Implement vfio_pci driver for mlx5 devices
  vfio/mlx5: Expose migration commands over mlx5 device
  vfio: Remove migration protocol v1 documentation
  vfio: Extend the device migration protocol with RUNNING_P2P
  vfio: Define device migration protocol v2
  ...

Merge tag 'hyperv-next-signed-20220322' of git://git./linux/kernel/git/hyperv/linux

Pull hyperv updates from Wei Liu:
 "Minor patches from various people"

* tag 'hyperv-next-signed-20220322' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux:
  x86/hyperv: Output host build info as normal Windows version number
  hv_balloon: rate-limit "Unhandled message" warning
  drivers: hv: log when enabling crash_kexec_post_notifiers
  hv_utils: Add comment about max VMbus packet size in VSS driver
  Drivers: hv: Compare cpumasks and not their weights in init_vp_index()
  Drivers: hv: Rename 'alloced' to 'allocated'
  Drivers: hv: vmbus: Use struct_size() helper in kmalloc()

Merge tag 'for-linus' of git://git./virt/kvm/kvm

Pull kvm updates from Paolo Bonzini:
 "ARM:
   - Proper emulation of the OSLock feature of the debug architecture

   - Scalibility improvements for the MMU lock when dirty logging is on

   - New VMID allocator, which will eventually help with SVA in VMs

   - Better support for PMUs in heterogenous systems

   - PSCI 1.1 support, enabling support for SYSTEM_RESET2

   - Implement CONFIG_DEBUG_LIST at EL2

   - Make CONFIG_ARM64_ERRATUM_2077057 default y

   - Reduce the overhead of VM exit when no interrupt is pending

   - Remove traces of 32bit ARM host support from the documentation

   - Updated vgic selftests

   - Various cleanups, doc updates and spelling fixes

  RISC-V:
   - Prevent KVM_COMPAT from being selected

   - Optimize __kvm_riscv_switch_to() implementation

   - RISC-V SBI v0.3 support

  s390:
   - memop selftest

   - fix SCK locking

   - adapter interruptions virtualization for secure guests

   - add Claudio Imbrenda as maintainer

   - first step to do proper storage key checking

  x86:
   - Continue switching kvm_x86_ops to static_call(); introduce
     static_call_cond() and __static_call_ret0 when applicable.

   - Cleanup unused arguments in several functions

   - Synthesize AMD 0x80000021 leaf

   - Fixes and optimization for Hyper-V sparse-bank hypercalls

   - Implement Hyper-V's enlightened MSR bitmap for nested SVM

   - Remove MMU auditing

   - Eager splitting of page tables (new aka "TDP" MMU only) when dirty
     page tracking is enabled

   - Cleanup the implementation of the guest PGD cache

   - Preparation for the implementation of Intel IPI virtualization

   - Fix some segment descriptor checks in the emulator

   - Allow AMD AVIC support on systems with physical APIC ID above 255

   - Better API to disable virtualization quirks

   - Fixes and optimizations for the zapping of page tables:

      - Zap roots in two passes, avoiding RCU read-side critical
        sections that last too long for very large guests backed by 4
        KiB SPTEs.

      - Zap invalid and defunct roots asynchronously via
        concurrency-managed work queue.

      - Allowing yielding when zapping TDP MMU roots in response to the
        root's last reference being put.

      - Batch more TLB flushes with an RCU trick. Whoever frees the
        paging structure now holds RCU as a proxy for all vCPUs running
        in the guest, i.e. to prolongs the grace period on their behalf.
        It then kicks the the vCPUs out of guest mode before doing
        rcu_read_unlock().

  Generic:
   - Introduce __vcalloc and use it for very large allocations that need
     memcg accounting"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (246 commits)
  KVM: use kvcalloc for array allocations
  KVM: x86: Introduce KVM_CAP_DISABLE_QUIRKS2
  kvm: x86: Require const tsc for RT
  KVM: x86: synthesize CPUID leaf 0x80000021h if useful
  KVM: x86: add support for CPUID leaf 0x80000021
  KVM: x86: do not use KVM_X86_OP_OPTIONAL_RET0 for get_mt_mask
  Revert "KVM: x86/mmu: Zap only TDP MMU leafs in kvm_zap_gfn_range()"
  kvm: x86/mmu: Flush TLB before zap_gfn_range releases RCU
  KVM: arm64: fix typos in comments
  KVM: arm64: Generalise VM features into a set of flags
  KVM: s390: selftests: Add error memop tests
  KVM: s390: selftests: Add more copy memop tests
  KVM: s390: selftests: Add named stages for memop test
  KVM: s390: selftests: Add macro as abstraction for MEM_OP
  KVM: s390: selftests: Split memop tests
  KVM: s390x: fix SCK locking
  RISC-V: KVM: Implement SBI HSM suspend call
  RISC-V: KVM: Add common kvm_riscv_vcpu_wfi() function
  RISC-V: Add SBI HSM suspend related defines
  RISC-V: KVM: Implement SBI v0.3 SRST extension
  ...

Merge tag 'tomoyo-pr-20220322' of git://git.osdn.net/gitroot/tomoyo/tomoyo-test1

Pull tomoyo update from Tetsuo Handa:
 "Avoid unnecessarily leaking kernel command line arguments"

* tag 'tomoyo-pr-20220322' of git://git.osdn.net/gitroot/tomoyo/tomoyo-test1:
  TOMOYO: fix __setup handlers return values

Merge tag 'flexible-array-transformations-5.18-rc1' of git://git./linux/kernel/git/gustavoars/linux

Pull flexible-array transformations from Gustavo Silva:
 "Treewide patch that replaces zero-length arrays with flexible-array
  members.

  This has been baking in linux-next for a whole development cycle"

* tag 'flexible-array-transformations-5.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux:
  treewide: Replace zero-length arrays with flexible-array members

Merge tag 'prlimit-tasklist_lock-for-v5.18' of git://git./linux/kernel/git/ebiederm/user-namespace

Pull tasklist_lock optimizations from Eric Biederman:
 "prlimit and getpriority tasklist_lock optimizations

  The tasklist_lock popped up as a scalability bottleneck on some
  testing workloads. The readlocks in do_prlimit and set/getpriority are
  not necessary in all cases.

  Based on a cycles profile, it looked like ~87% of the time was spent
  in the kernel, ~42% of which was just trying to get *some* spinlock
  (queued_spin_lock_slowpath, not necessarily the tasklist_lock).

  The big offenders (with rough percentages in cycles of the overall
  trace):
   - do_wait 11%
   - setpriority 8% (done previously in commit 7f8ca0edfe07)
   - kill 8%
   - do_exit 5%
   - clone 3%
   - prlimit64 2%   (this patchset)
   - getrlimit 1%   (this patchset)

  I can't easily test this patchset on the original workload for various
  reasons. Instead, I used the microbenchmark below to at least verify
  there was some improvement. This patchset had a 28% speedup (12% from
  baseline to set/getprio, then another 14% for prlimit).

  This series used to do the setpriority case, but an almost identical
  change was merged as commit 7f8ca0edfe07 ("kernel/sys.c: only take
  tasklist_lock for get/setpriority(PRIO_PGRP)") so that has been
  dropped from here.

  One interesting thing is that my libc's getrlimit() was calling
  prlimit64, so hoisting the read_lock(tasklist_lock) into sys_prlimit64
  had no effect - it essentially optimized the older syscalls only. I
  didn't do that in this patchset, but figured I'd mention it since it
  was an option from the previous patch's discussion"

micobenchmark.c:
---------------
int main(int argc, char **argv)
{
pid_t child;
struct rlimit rlim[1];

fork(); fork(); fork(); fork(); fork(); fork();

for (int i = 0; i < 5000; i++) {
child = fork();
if (child < 0)
exit(1);
if (child > 0) {
usleep(1000);
kill(child, SIGTERM);
waitpid(child, NULL, 0);
} else {
for (;;) {
setpriority(PRIO_PROCESS, 0,
    getpriority(PRIO_PROCESS, 0));
getrlimit(RLIMIT_CPU, rlim);
}
}
}

return 0;
}

Link: https://lore.kernel.org/lkml/20211213220401.1039578-1-brho@google.com/
Link: https://lore.kernel.org/lkml/20220105212828.197013-1-brho@google.com/
Link: https://lore.kernel.org/lkml/20220106172041.522167-1-brho@google.com/
* tag 'prlimit-tasklist_lock-for-v5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  prlimit: do not grab the tasklist_lock
  prlimit: make do_prlimit() static

Merge tag 'fs.rt.v5.18' of git://git./linux/kernel/git/brauner/linux

Pull mount attributes PREEMPT_RT update from Christian Brauner:
 "This contains Sebastian's fix to make changing mount
  attributes/getting write access compatible with CONFIG_PREEMPT_RT.

  The change only applies when users explicitly opt-in to real-time via
  CONFIG_PREEMPT_RT otherwise things are exactly as before. We've waited
  quite a long time with this to make sure folks could take a good look"

* tag 'fs.rt.v5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux:
  fs/namespace: Boost the mount_lock.lock owner instead of spinning on PREEMPT_RT.

Merge tag 'fs.v5.18' of git://git./linux/kernel/git/brauner/linux

Pull mount_setattr updates from Christian Brauner:
 "This contains a few more patches to massage the mount_setattr()
  codepaths and one minor fix to reuse a helper we added some time back.

  The final two patches do similar cleanups in different ways. One patch
  is mine and the other is Al's who was nice enough to give me a branch
  for it.

  Since his came in later and my branch had been sitting in -next for
  quite some time we just put his on top instead of swap them"

* tag 'fs.v5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux:
  mount_setattr(): clean the control flow and calling conventions
  fs: clean up mount_setattr control flow
  fs: don't open-code mnt_hold_writers()
  fs: simplify check in mount_setattr_commit()
  fs: add mnt_allow_writers() and simplify mount_setattr_prepare()

Revert "ubsan, kcsan: Don't combine sanitizer with kcov on clang"

This reverts commit ea91a1d45d19469001a4955583187b0d75915759.

Since df05c0e9496c ("Documentation: Raise the minimum supported version
of LLVM to 11.0.0") the minimum Clang version is now 11.0, which fixed
the UBSAN/KCSAN vs. KCOV incompatibilities.

Link: https://bugs.llvm.org/show_bug.cgi?id=45831
Link: https://lkml.kernel.org/r/YaodyZzu0MTCJcvO@elver.google.com
Link: https://lkml.kernel.org/r/20220128105631.509772-1-elver@google.com
Signed-off-by: Marco Elver <elver@google.com>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel/resource: fix kfree() of bootmem memory again

Since commit ebff7d8f270d ("mem hotunplug: fix kfree() of bootmem
memory"), we could get a resource allocated during boot via
alloc_resource().  And it's required to release the resource using
free_resource().  Howerver, many people use kfree directly which will
result in kernel BUG.  In order to fix this without fixing every call
site, just leak a couple of bytes in such corner case.

Link: https://lkml.kernel.org/r/20220217083619.19305-1-linmiaohe@huawei.com
Fixes: ebff7d8f270d ("mem hotunplug: fix kfree() of bootmem memory")
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Suggested-by: David Hildenbrand <david@redhat.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Alistair Popple <apopple@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kcov: properly handle subsequent mmap calls

Allocate the kcov buffer during KCOV_MODE_INIT in order to untie mmapping
of a kcov instance and the actual coverage collection process. Modify
kcov_mmap, so that it can be reliably used any number of times once
KCOV_MODE_INIT has succeeded.

These changes to the user-facing interface of the tool only weaken the
preconditions, so all existing user space code should remain compatible
with the new version.

Link: https://lkml.kernel.org/r/20220117153634.150357-3-nogikh@google.com
Signed-off-by: Aleksandr Nogikh <nogikh@google.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Marco Elver <elver@google.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Taras Madan <tarasmadan@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kcov: split ioctl handling into locked and unlocked parts

Patch series "kcov: improve mmap processing", v3.

Subsequent mmaps of the same kcov descriptor currently do not update the
virtual memory of the task and yet return 0 (success).  This is
counter-intuitive and may lead to unexpected memory access errors.

Also, this unnecessarily limits the functionality of kcov to only the
simplest usage scenarios.  Kcov instances are effectively forever attached
to their first address spaces and it becomes impossible to e.g.  reuse the
same kcov handle in forked child processes without mmapping the memory
first.  This is exactly what we tried to do in syzkaller and inadvertently
came upon this behavior.

This patch series addresses the problem described above.

This patch (of 3):

Currently all ioctls are de facto processed under a spinlock in order to
serialise them.  This, however, prohibits the use of vmalloc and other
memory management functions in the implementations of those ioctls,
unnecessary complicating any further changes to the code.

Let all ioctls first be processed inside the kcov_ioctl() function which
should execute the ones that are not compatible with spinlock and then
pass control to kcov_ioctl_locked() for all other ones.
KCOV_REMOTE_ENABLE is processed both in kcov_ioctl() and
kcov_ioctl_locked() as the steps are easily separable.

Although it is still compatible with a spinlock, move KCOV_INIT_TRACE
handling to kcov_ioctl(), so that the changes from the next commit are
easier to follow.

Link: https://lkml.kernel.org/r/20220117153634.150357-1-nogikh@google.com
Link: https://lkml.kernel.org/r/20220117153634.150357-2-nogikh@google.com
Signed-off-by: Aleksandr Nogikh <nogikh@google.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Taras Madan <tarasmadan@google.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

panic: move panic_print before kmsg dumpers

The panic_print setting allows users to collect more information in a
panic event, like memory stats, tasks, CPUs backtraces, etc.  This is an
interesting debug mechanism, but currently the print event happens *after*
kmsg_dump(), meaning that pstore, for example, cannot collect a dmesg with
the panic_print extra information.

This patch changes that in 2 steps:

(a) The panic_print setting allows to replay the existing kernel log
    buffer to the console (bit 5), besides the extra information dump.
    This functionality makes sense only at the end of the panic()
    function.  So, we hereby allow to distinguish the two situations by a
    new boolean parameter in the function panic_print_sys_info().

(b) With the above change, we can safely call panic_print_sys_info()
    before kmsg_dump(), allowing to dump the extra information when using
    pstore or other kmsg dumpers.

The additional messages from panic_print could overwrite the oldest
messages when the buffer is full.  The only reasonable solution is to use
a large enough log buffer, hence we added an advice into the kernel
parameters documentation about that.

Link: https://lkml.kernel.org/r/20220214141308.841525-1-gpiccoli@igalia.com
Signed-off-by: Guilherme G. Piccoli <gpiccoli@igalia.com>
Acked-by: Baoquan He <bhe@redhat.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Feng Tang <feng.tang@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

panic: add option to dump all CPUs backtraces in panic_print

Currently the "panic_print" parameter/sysctl allows some interesting debug
information to be printed during a panic event.  This is useful for
example in cases the user cannot kdump due to resource limits, or if the
user collects panic logs in a serial output (or pstore) and prefers a fast
reboot instead of a kdump.

Happens that currently there's no way to see all CPUs backtraces in a
panic using "panic_print" on architectures that support that.  We do have
"oops_all_cpu_backtrace" sysctl, but although partially overlapping in the
functionality, they are orthogonal in nature: "panic_print" is a panic
tuning (and we have panics without oopses, like direct calls to panic() or
maybe other paths that don't go through oops_enter() function), and the
original purpose of "oops_all_cpu_backtrace" is to provide more
information on oopses for cases in which the users desire to continue
running the kernel even after an oops, i.e., used in non-panic scenarios.

So, we hereby introduce an additional bit for "panic_print" to allow
dumping the CPUs backtraces during a panic event.

Link: https://lkml.kernel.org/r/20211109202848.610874-3-gpiccoli@igalia.com
Signed-off-by: Guilherme G. Piccoli <gpiccoli@igalia.com>
Reviewed-by: Feng Tang <feng.tang@intel.com>
Cc: Iurii Zaikin <yzaikin@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Samuel Iglesias Gonsalvez <siglesias@igalia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

docs: sysctl/kernel: add missing bit to panic_print

Patch series "Some improvements on panic_print".

This is a mix of a documentation fix with some additions to the
"panic_print" syscall / parameter.  The goal here is being able to collect
all CPUs backtraces during a panic event and also to enable "panic_print"
in a kdump event - details of the reasoning and design choices in the
patches.

This patch (of 3):

Commit de6da1e8bcf0 ("panic: add an option to replay all the printk
message in buffer") added a new bit to the sysctl/kernel parameter
"panic_print", but the documentation was added only in
kernel-parameters.txt, not in the sysctl guide.

Fix it here by adding bit 5 to sysctl admin-guide documentation.

[rdunlap@infradead.org: fix table format warning]
Link: https://lkml.kernel.org/r/20220109055635.6999-1-rdunlap@infradead.org
Link: https://lkml.kernel.org/r/20211109202848.610874-1-gpiccoli@igalia.com
Link: https://lkml.kernel.org/r/20211109202848.610874-2-gpiccoli@igalia.com
Fixes: de6da1e8bcf0 ("panic: add an option to replay all the printk message in buffer")
Signed-off-by: Guilherme G. Piccoli <gpiccoli@igalia.com>
Reviewed-by: Feng Tang <feng.tang@intel.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Iurii Zaikin <yzaikin@google.com>
Cc: Samuel Iglesias Gonsalvez <siglesias@igalia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

taskstats: remove unneeded dead assignment

make clang-analyzer on x86_64 defconfig caught my attention with:

  kernel/taskstats.c:120:2: warning: Value stored to 'rc' is never read \
  [clang-analyzer-deadcode.DeadStores]
          rc = 0;
          ^

Commit d94a041519f3 ("taskstats: free skb, avoid returns in
send_cpu_listeners") made send_cpu_listeners() not return a value and
hence, the rc variable remained only to be used within the loop where
it is always assigned before read and it does not need any other
initialisation.

So, simply remove this unneeded dead initializing assignment.

As compilers will detect this unneeded assignment and optimize this anyway,
the resulting object code is identical before and after this change.

No functional change. No change to object code.

[akpm@linux-foundation.org: reduce scope of `rc']

Link: https://lkml.kernel.org/r/20220307093942.21310-1-lukas.bulwahn@gmail.com
Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Tom Rix <trix@redhat.com>
Cc: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kasan: no need to unset panic_on_warn in end_report()

panic_on_warn is unset inside panic(), so no need to unset it before
calling panic() in end_report().

Link: https://lkml.kernel.org/r/1644324666-15947-6-git-send-email-yangtiezhu@loongson.cn
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Xuefeng Li <lixuefeng@loongson.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ubsan: no need to unset panic_on_warn in ubsan_epilogue()

panic_on_warn is unset inside panic(), so no need to unset it before
calling panic() in ubsan_epilogue().

Link: https://lkml.kernel.org/r/1644324666-15947-5-git-send-email-yangtiezhu@loongson.cn
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Xuefeng Li <lixuefeng@loongson.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

panic: unset panic_on_warn inside panic()

In the current code, the following three places need to unset
panic_on_warn before calling panic() to avoid recursive panics:

kernel/kcsan/report.c: print_report()
kernel/sched/core.c: __schedule_bug()
mm/kfence/report.c: kfence_report_error()

In order to avoid copy-pasting "panic_on_warn = 0" all over the places,
it is better to move it inside panic() and then remove it from the other
places.

Link: https://lkml.kernel.org/r/1644324666-15947-4-git-send-email-yangtiezhu@loongson.cn
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Xuefeng Li <lixuefeng@loongson.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

docs: kdump: add scp example to write out the dump file

Except cp and makedumpfile, add scp example to write out the dump file.

Link: https://lkml.kernel.org/r/1644324666-15947-3-git-send-email-yangtiezhu@loongson.cn
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Acked-by: Baoquan He <bhe@redhat.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Marco Elver <elver@google.com>
Cc: Xuefeng Li <lixuefeng@loongson.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

docs: kdump: update description about sysfs file system support

Patch series "Update doc and fix some issues about kdump", v2.

This patch (of 5):

After commit 6a108a14fa35 ("kconfig: rename CONFIG_EMBEDDED to
CONFIG_EXPERT"), "Configure standard kernel features (for small
systems)" is not exist, we should use "Configure standard kernel
features (expert users)" now.

Link: https://lkml.kernel.org/r/1644324666-15947-1-git-send-email-yangtiezhu@loongson.cn
Link: https://lkml.kernel.org/r/1644324666-15947-2-git-send-email-yangtiezhu@loongson.cn
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Acked-by: Baoquan He <bhe@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Marco Elver <elver@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Xuefeng Li <lixuefeng@loongson.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arm64: mm: use IS_ENABLED(CONFIG_KEXEC_CORE) instead of #ifdef

Replace the conditional compilation using "#ifdef CONFIG_KEXEC_CORE" by a
check for "IS_ENABLED(CONFIG_KEXEC_CORE)", to simplify the code and
increase compile coverage.

Link: https://lkml.kernel.org/r/20211206160514.2000-5-jszhang@kernel.org
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Baoquan He <bhe@redhat.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexandre Ghiti <alex@ghiti.fr>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Palmer Dabbelt <palmer@rivosinc.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

x86/setup: use IS_ENABLED(CONFIG_KEXEC_CORE) instead of #ifdef

Replace the conditional compilation using "#ifdef CONFIG_KEXEC_CORE" by a
check for "IS_ENABLED(CONFIG_KEXEC_CORE)", to simplify the code and
increase compile coverage.

Link: https://lkml.kernel.org/r/20211206160514.2000-4-jszhang@kernel.org
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Acked-by: Baoquan He <bhe@redhat.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexandre Ghiti <alex@ghiti.fr>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Palmer Dabbelt <palmer@rivosinc.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

riscv: mm: init: use IS_ENABLED(CONFIG_KEXEC_CORE) instead of #ifdef

Replace the conditional compilation using "#ifdef CONFIG_KEXEC_CORE" by a
check for "IS_ENABLED(CONFIG_KEXEC_CORE)", to simplify the code and
increase compile coverage.

Link: https://lkml.kernel.org/r/20211206160514.2000-3-jszhang@kernel.org
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Acked-by: Palmer Dabbelt <palmer@rivosinc.com>
Acked-by: Baoquan He <bhe@redhat.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexandre Ghiti <alex@ghiti.fr>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kexec: make crashk_res, crashk_low_res and crash_notes symbols always visible

Patch series "kexec: use IS_ENABLED(CONFIG_KEXEC_CORE) instead of #ifdef", v2.

Replace the conditional compilation using "#ifdef CONFIG_KEXEC_CORE" by
a check for "IS_ENABLED(CONFIG_KEXEC_CORE)", to simplify the code and
increase compile coverage.

I only modified x86, arm, arm64 and riscv, other architectures such as
sh, powerpc and s390 are better to be kept kexec code as-is so they are
not touched.

This patch (of 5):

Make the forward declarations of crashk_res, crashk_low_res and
crash_notes always visible.  Code referring to these symbols can then just
check for IS_ENABLED(CONFIG_KEXEC_CORE), instead of requiring conditional
compilation using an #ifdef, thus preparing to increase compile coverage
and simplify the code.

Link: https://lkml.kernel.org/r/20211206160514.2000-1-jszhang@kernel.org
Link: https://lkml.kernel.org/r/20211206160514.2000-2-jszhang@kernel.org
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Acked-by: Baoquan He <bhe@redhat.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Alexandre Ghiti <alex@ghiti.fr>
Cc: Palmer Dabbelt <palmer@rivosinc.com>
Cc: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

cgroup: use irqsave in cgroup_rstat_flush_locked().

All callers of cgroup_rstat_flush_locked() acquire cgroup_rstat_lock
either with spin_lock_irq() or spin_lock_irqsave().
cgroup_rstat_flush_locked() itself acquires cgroup_rstat_cpu_lock which
is a raw_spin_lock.  This lock is also acquired in
cgroup_rstat_updated() in IRQ context and therefore requires _irqsave()
locking suffix in cgroup_rstat_flush_locked().

Since there is no difference between spin_lock_t and raw_spin_lock_t on
!RT lockdep does not complain here.  On RT lockdep complains because the
interrupts were not disabled here and a deadlock is possible.

Acquire the raw_spin_lock_t with disabled interrupts.

Link: https://lkml.kernel.org/r/20220301122143.1521823-2-bigeasy@linutronix.de
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Zefan Li <lizefan.x@bytedance.com>
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Subject: cgroup: add a comment to cgroup_rstat_flush_locked().

Add a comment why spin_lock_irq() -> raw_spin_lock_irqsave() is needed.

Link: https://lkml.kernel.org/r/Yh+DOK73hfVV5ThX@linutronix.de
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Zefan Li <lizefan.x@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fat: use pointer to simple type in put_user()

The put_user(val,ptr) macro wants a pointer to a simple type, but in
fat_ioctl_filldir() the d_name field references an "array of chars".  Be
more accurate and explicitly give the pointer to the first character of
the d_name[] array.

I noticed that issue while trying to optimize the parisc put_user()
macro and used an intermediate variable to store the pointer.  In that
case I got this error:

  In file included from include/linux/uaccess.h:11,
                   from include/linux/compat.h:17,
                   from fs/fat/dir.c:18:
  fs/fat/dir.c: In function `fat_ioctl_filldir':
  fs/fat/dir.c:725:33: error: invalid initializer
    725 |                 if (put_user(0, d2->d_name)                     ||         \
        |                                 ^~
  include/asm/uaccess.h:152:33: note: in definition of macro `__put_user'
    152 |         __typeof__(ptr) __ptr = ptr;                            \
        |                                 ^~~
  fs/fat/dir.c:759:1: note: in expansion of macro `FAT_IOCTL_FILLDIR_FUNC'
    759 | FAT_IOCTL_FILLDIR_FUNC(fat_ioctl_filldir, __fat_dirent)

Andreas Schwab <schwab@linux-m68k.org> suggested to use

   __typeof__(&*(ptr)) __ptr = ptr;

instead.  This works, but nevertheless it's probably reasonable to fix
the original caller too.

Link: https://lkml.kernel.org/r/Ygo+A9MREmC1H3kr@p100
Signed-off-by: Helge Deller <deller@gmx.de>
Acked-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: David Laight <David.Laight@aculab.com>
Cc: Andreas Schwab <schwab@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

minix: fix bug when opening a file with O_DIRECT

Testcase:
1. create a minix file system and mount it
2. open a file on the file system with O_RDWR|O_CREAT|O_TRUNC|O_DIRECT
3. open fails with -EINVAL but leaves an empty file behind. All other
   open() failures don't leave the failed open files behind.

It is hard to check the direct_IO op before creating the inode.  Just as
ext4 and btrfs do, this patch will resolve the issue by allowing to
create the file with O_DIRECT but returning error when writing the file.

Link: https://lkml.kernel.org/r/20220107133626.413379-1-qhjin.dev@gmail.com
Signed-off-by: Qinghua Jin <qhjin.dev@gmail.com>
Reported-by: Colin Ian King <colin.king@intel.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/pipe.c: local vars have to match types of proper pipe_inode_info fields

head, tail, ring_size are declared as unsigned int, so all local
variables that operate with these fields have to be unsigned to avoid
signed integer overflow.

Right now, it isn't an issue because the maximum pipe size is limited by
1U<<31.

Link: https://lkml.kernel.org/r/20220106171946.36128-1-avagin@gmail.com
Signed-off-by: Andrei Vagin <avagin@gmail.com>
Suggested-by: Dmitry Safonov <0x7f454c46@gmail.com>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/pipe: use kvcalloc to allocate a pipe_buffer array

Right now, kcalloc is used to allocate a pipe_buffer array.  The size of
the pipe_buffer struct is 40 bytes.  kcalloc allows allocating reliably
chunks with sizes less or equal to PAGE_ALLOC_COSTLY_ORDER (3).  It
means that the maximum pipe size is 3.2MB in this case.

In CRIU, we use pipes to dump processes memory.  CRIU freezes a target
process, injects a parasite code into it and then this code splices
memory into pipes.  If a maximum pipe size is small, we need to do many
iterations or create many pipes.

kvcalloc attempt to allocate physically contiguous memory, but upon
failure, fall back to non-contiguous (vmalloc) allocation and so it
isn't limited by PAGE_ALLOC_COSTLY_ORDER.

The maximum pipe size for non-root users is limited by the
/proc/sys/fs/pipe-max-size sysctl that is 1MB by default, so only the
root user will be able to trigger vmalloc allocations.

Link: https://lkml.kernel.org/r/20220104171058.22580-1-avagin@gmail.com
Signed-off-by: Andrei Vagin <avagin@gmail.com>
Reviewed-by: Dmitry Safonov <0x7f454c46@gmail.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

init/main.c: return 1 from handled __setup() functions

initcall_blacklist() should return 1 to indicate that it handled its
cmdline arguments.

set_debug_rodata() should return 1 to indicate that it handled its
cmdline arguments.  Print a warning if the option string is invalid.

This prevents these strings from being added to the 'init' program's
environment as they are not init arguments/parameters.

Link: https://lkml.kernel.org/r/20220221050901.23985-1-rdunlap@infradead.org
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: Igor Zhbanov <i.zhbanov@omprussia.ru>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

init.h: improve __setup and early_param documentation

Igor noted in [1] that there are quite a few __setup() handling
functions that return incorrect values.  Doing this can be harmless, but
it can also cause strings to be added to init's argument or environment
list, polluting them.

Since __setup() handling and return values are not documented, first add
documentation for that.  Also add more documentation for early_param()
handling and return values.

For __setup() functions, returning 0 (not handled) has questionable
value if it is just a malformed option value, as in

  rodata=junk

since returning 0 would just cause "rodata=junk" to be added to init's
environment unnecessarily:

  Run /sbin/init as init process
    with arguments:
      /sbin/init
    with environment:
      HOME=/
      TERM=linux
      splash=native
      rodata=junk

Also, there are no recommendations on whether to print a warning when an
unknown parameter value is seen.  I am not addressing that here.

[1] lore.kernel.org/r/64644a2f-4a20-bab3-1e15-3b2cdd0defe3@omprussia.ru

Link: https://lkml.kernel.org/r/20220221050852.1147-1-rdunlap@infradead.org
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: Igor Zhbanov <i.zhbanov@omprussia.ru>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

init: use ktime_us_delta() to make initcall_debug log more precise

Use ktime_us_delta() to make the initcall_debug log more precise than
right shifting the result of ktime_to_ns() by 10 bits.

Link: https://lkml.kernel.org/r/20220209053350.15771-1-mark-pk.tsai@mediatek.com
Signed-off-by: Mark-PK Tsai <mark-pk.tsai@mediatek.com>
Reviewed-by: Andrew Halaney <ahalaney@redhat.com>
Tested-by: Andrew Halaney <ahalaney@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Kees Cook <keescook@chromium.org>
Cc: Valentin Schneider <valentin.schneider@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: YJ Chiang <yj.chiang@mediatek.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

checkpatch: use python3 to find codespell dictionary

Commit 0ee3e7b8893e ("checkpatch: get default codespell dictionary path
from package location") introduced the ability to search for the
codespell dictionary rather than hardcoding its path.

codespell requires Python 3.6 or above, but on some systems, the python
executable is a Python 2.7 interpreter.  In this case, searching for the
dictionary fails, subsequently making codespell fail:

  No codespell typos will be found - file '/usr/share/codespell/dictionary.txt': No such file or directory

So, use python3 to remove ambiguity.

In addition, when searching for dictionary.txt, do not check if the
codespell executable exists since,

 - checkpatch.pl only uses dictionary.txt, not the codespell
   executable.

 - codespell can be installed via a Python package manager, in which
   case the codespell executable may not be present in a typical $PATH,
   but a dictionary does exist.

Link: https://lkml.kernel.org/r/20220309180048.147672-1-sagarmp@cs.unc.edu
Signed-off-by: Sagar Patel <sagarmp@cs.unc.edu>
Reviewed-by: Peter Ujfalusi <peter.ujfalusi@linux.intel.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

checkpatch: add early_param exception to blank line after struct/function test

Add early_param as another exception to the blank line preferred after
function/struct/union declaration or definition test.

Link: https://lkml.kernel.org/r/3bd6ada59f411a7685d7e64eeb670540d4bfdcde.camel@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Cc: Dwaipayan Ray <dwaipayanray1@gmail.com>
Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

checkpatch: add --fix option for some TRAILING_STATEMENTS

Single line code like:

if (foo) bar;

should generally be written:

if (foo)
bar;

Add a --fix test to do so.

This fix is not done when an ASSIGN_IN_IF in the same line exists.

Link: https://lkml.kernel.org/r/20220128185924.80137-2-joe@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Cc: Dwaipayan Ray <dwaipayanray1@gmail.com>
Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

checkpatch: prefer MODULE_LICENSE("GPL") over MODULE_LICENSE("GPL v2")

There is no effective difference.

Given the large number of uses of "GPL v2", emit this message only for
patches as a trivial treeside sed could be done one day.

Ref: commit bf7fbeeae6db ("module: Cure the MODULE_LICENSE "GPL" vs. "GPL v2" bogosity")

Link: https://lkml.kernel.org/r/20220128185924.80137-1-joe@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Cc: Dwaipayan Ray <dwaipayanray1@gmail.com>
Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib: bitmap: fix many kernel-doc warnings

Fix kernel-doc warings in lib/bitmap.c:

  lib/bitmap.c:498: warning: Function parameter or member 'buf' not described in 'bitmap_print_to_buf'
  lib/bitmap.c:498: warning: Function parameter or member 'maskp' not described in 'bitmap_print_to_buf'
  lib/bitmap.c:498: warning: Function parameter or member 'nmaskbits' not described in 'bitmap_print_to_buf'
  lib/bitmap.c:498: warning: Function parameter or member 'off' not described in 'bitmap_print_to_buf'
  lib/bitmap.c:498: warning: Function parameter or member 'count' not described in 'bitmap_print_to_buf'
  lib/bitmap.c:561: warning: contents before sections
  lib/bitmap.c:606: warning: Function parameter or member 'buf' not described in 'bitmap_print_list_to_buf'
  lib/bitmap.c:606: warning: Function parameter or member 'maskp' not described in 'bitmap_print_list_to_buf'
  lib/bitmap.c:606: warning: Function parameter or member 'nmaskbits' not described in 'bitmap_print_list_to_buf'
  lib/bitmap.c:606: warning: Function parameter or member 'off' not described in 'bitmap_print_list_to_buf'
  lib/bitmap.c:606: warning: Function parameter or member 'count' not described in 'bitmap_print_list_to_buf'
  lib/bitmap.c:819: warning: missing initial short description on line:
   * bitmap_parselist_user()

This still leaves 15 warnings for function return values not described,
similar to this one:

  bitmap.c:890: warning: No description found for return value of 'bitmap_parse'

Link: https://lkml.kernel.org/r/20220306065823.5153-1-rdunlap@infradead.org
Fixes: 1fae562983ca ("cpumask: introduce cpumap_print_list/bitmask_to_buf to support large bitmask and list")
Fixes: 4b060420a596 ("bitmap, irq: add smp_affinity_list interface to /proc/irq")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Yury Norov <yury.norov@gmail.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Tian Tao <tiantao6@hisilicon.com>
Cc: Mike Travis <mike.travis@hpe.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>