I've got the following splat after enabling preemption:

[    3.724721] BUG: using __this_cpu_add() in preemptible [00000000] code: swapper/0/1
[    3.734630] caller is __this_cpu_preempt_check+0x38/0x50
[    3.740635] CPU: 1 PID: 1 Comm: swapper/0 Not tainted 5.15.0-rc4-64bit+ #324
[    3.744605] Hardware name: 9000/785/C8000
[    3.744605] Backtrace:
[    3.744605]  [<00000000401d9d58>] show_stack+0x74/0xb0
[    3.744605]  [<0000000040c27bd4>] dump_stack_lvl+0x10c/0x188
[    3.744605]  [<0000000040c27c84>] dump_stack+0x34/0x48
[    3.744605]  [<0000000040c33438>] check_preemption_disabled+0x178/0x1b0
[    3.744605]  [<0000000040c334f8>] __this_cpu_preempt_check+0x38/0x50
[    3.744605]  [<00000000401d632c>] flush_tlb_all+0x58/0x2e0
[    3.744605]  [<00000000401075c0>] 0x401075c0
[    3.744605]  [<000000004010b8fc>] 0x4010b8fc
[    3.744605]  [<00000000401080fc>] 0x401080fc
[    3.744605]  [<00000000401d5224>] do_one_initcall+0x128/0x378
[    3.744605]  [<0000000040102de8>] 0x40102de8
[    3.744605]  [<0000000040c33864>] kernel_init+0x60/0x3a8
[    3.744605]  [<00000000401d1020>] ret_from_kernel_thread+0x20/0x28
[    3.744605]

Fix this by moving the __inc_irq_stat() into the locked section.
Signed-off-by: Sven Schnelle <svens@stackframe.org>
Signed-off-by: Helge Deller <deller@gmx.de>

Otherwise we might not stop all other CPUs.
Signed-off-by: Sven Schnelle <svens@stackframe.org>
Signed-off-by: Helge Deller <deller@gmx.de>

preempt_count in struct thread_info is unsigned int,
but the entry.S code used LDREG, which generates a 64 bit
load when compiled for 64 bit. Fix this to use an ldw and
also change the condition in the compare one line below
to only compares 32 bits, although ldw zero extends, and
that should work with a 64 bit compare.
Signed-off-by: Sven Schnelle <svens@stackframe.org>
Signed-off-by: Helge Deller <deller@gmx.de>

Parts of both functions are the same, so deduplicate them. No functional
change.
Signed-off-by: Sven Schnelle <svens@stackframe.org>
Signed-off-by: Helge Deller <deller@gmx.de>

flush_cache_mm() and flush_cache_range() fetch %sr3 via mfsp().
If it matches mm->context, they flush caches and the TLB. However,
the TLB is cpu-local, so if the code gets preempted shortly after
the mfsp(), and later resumed on another CPU, the wrong TLB is flushed.
Signed-off-by: Sven Schnelle <svens@stackframe.org>
Signed-off-by: Helge Deller <deller@gmx.de>

Signed-off-by: Helge Deller <deller@gmx.de>

It's shorter and kfence currently depends on this stack unwinding
implementation.
Signed-off-by: Helge Deller <deller@gmx.de>

When adding kfence support, we need to tell kfence_handle_page_fault()
if the interrupted assembler statement is a read or write operation.
Signed-off-by: Helge Deller <deller@gmx.de>

I have no idea why get_user() is used there, but we're unwinding the
kernel stack, so we should use copy_from_kernel_nofault().
Signed-off-by: Sven Schnelle <svens@stackframe.org>
Signed-off-by: Helge Deller <deller@gmx.de>

Pull clk fix from Stephen Boyd:
 "One fix for the composite clk that broke when we changed this clk type
  to use the determine_rate instead of round_rate clk op by default.
  This caused lots of problems on Rockchip SoCs because they heavily use
  the composite clk code to model the clk tree"

* tag 'clk-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux:
  clk: composite: Also consider .determine_rate for rate + mux composites

Pull RISC-V fixes from Palmer Dabbelt:
 "These are pretty late, but they do fix concrete issues.

   - ensure the trap vector's address is aligned.

   - avoid re-populating the KASAN shadow memory.

   - allow kasan to build without warnings, which have recently become
     errors"

* tag 'riscv-for-linus-5.15-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
  riscv: Fix asan-stack clang build
  riscv: Do not re-populate shadow memory with kasan_populate_early_shadow
  riscv: fix misalgned trap vector base address

Pull powerpc fixes from Michael Ellerman:
 "Three commits fixing some issues introduced with the recent IOMMU
  changes we merged.

  Thanks to Alexey Kardashevskiy"

* tag 'powerpc-5.15-6' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/pseries/iommu: Create huge DMA window if no MMIO32 is present
  powerpc/pseries/iommu: Check if the default window in use before removing it
  powerpc/pseries/iommu: Use correct vfree for it_map

Pull gpio fixes from Bartosz Golaszewski:

 - fix the return value check when parsing the ngpios property in
   gpio-xgs-iproc

 - check the return value of bgpio_init() in gpio-mlxbf2

* tag 'gpio-fixes-for-v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux:
  gpio: mlxbf2.c: Add check for bgpio_init failure
  gpio: xgs-iproc: fix parsing of ngpios property

Pull block fixes from Jens Axboe:

 - NVMe pull request:
      - fix nvmet-tcp header digest verification (Amit Engel)
      - fix a memory leak in nvmet-tcp when releasing a queue (Maurizio
        Lombardi)
      - fix nvme-tcp H2CData PDU send accounting again (Sagi Grimberg)
      - fix digest pointer calculation in nvme-tcp and nvmet-tcp (Varun
        Prakash)
      - fix possible nvme-tcp req->offset corruption (Varun Prakash)

 - Queue drain ordering fix (Ming)

 - Partition check regression for zoned devices (Shin'ichiro)

 - Zone queue restart fix (Naohiro)

* tag 'block-5.15-2021-10-29' of git://git.kernel.dk/linux-block:
  block: Fix partition check for host-aware zoned block devices
  nvmet-tcp: fix header digest verification
  nvmet-tcp: fix data digest pointer calculation
  nvme-tcp: fix data digest pointer calculation
  nvme-tcp: fix possible req->offset corruption
  block: schedule queue restart after BLK_STS_ZONE_RESOURCE
  block: drain queue after disk is removed from sysfs
  nvme-tcp: fix H2CData PDU send accounting (again)
  nvmet-tcp: fix a memory leak when releasing a queue

Pull MMC fixes from Ulf Hansson:

 - tmio: Re-enable card irqs after a reset

 - mtk-sd: Fixup probing of cqhci for crypto

 - cqhci: Fix support for suspend/resume

 - vub300: Fix control-message timeouts

 - dw_mmc-exynos: Fix support for tuning

 - winbond: Silences build errors on M68K

 - sdhci-esdhc-imx: Fix support for tuning

 - sdhci-pci: Read card detect from ACPI for Intel Merrifield

 - sdhci: Fix eMMC support for Thundercomm TurboX CM2290

* tag 'mmc-v5.15-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/ulfh/mmc:
  mmc: tmio: reenable card irqs after the reset callback
  mmc: mediatek: Move cqhci init behind ungate clock
  mmc: cqhci: clear HALT state after CQE enable
  mmc: vub300: fix control-message timeouts
  mmc: dw_mmc: exynos: fix the finding clock sample value
  mmc: winbond: don't build on M68K
  mmc: sdhci-esdhc-imx: clear the buffer_read_ready to reset standard tuning circuit
  mmc: sdhci-pci: Read card detect from ACPI for Intel Merrifield
  mmc: sdhci: Map more voltage level to SDHCI_POWER_330

Pull btrfs fixes from David Sterba:
 "Last minute fixes for crash on 32bit architectures when compression is
  in use. It's a regression introduced in 5.15-rc and I'd really like
  not let this into the final release, fixes via stable trees would add
  unnecessary delay.

  The problem is on 32bit architectures with highmem enabled, the pages
  for compression may need to be kmapped, while the patches removed that
  as we don't use GFP_HIGHMEM allocations anymore. The pages that don't
  come from local allocation still may be from highmem. Despite being on
  32bit there's enough such ARM machines in use so it's not a marginal
  issue.

  I did full reverts of the patches one by one instead of a huge one.
  There's one exception for the "lzo" revert as there was an
  intermediate patch touching the same code to make it compatible with
  subpage. I can't revert that one too, so the revert in lzo.c is
  manual. Qu Wenruo has worked on that with me and verified the changes"

* tag 'for-5.15-rc7-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  Revert "btrfs: compression: drop kmap/kunmap from lzo"
  Revert "btrfs: compression: drop kmap/kunmap from zlib"
  Revert "btrfs: compression: drop kmap/kunmap from zstd"
  Revert "btrfs: compression: drop kmap/kunmap from generic helpers"

Pull tracing comment fixes from Steven Rostedt:

 - Some bots have informed me that some of the ftrace functions
   kernel-doc has formatting issues.

 - Also, fix my snake instinct.

* tag 'trace-v5.15-rc6-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Fix misspelling of "missing"
  ftrace: Fix kernel-doc formatting issues

Pull crypto fix from Herbert Xu:
 "Fix a build-time warning in x86/sm4"

* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
  crypto: x86/sm4 - Fix invalid section entry size

Merge misc fixes from Andrew Morton:
 "11 patches.

  Subsystems affected by this patch series: mm (memcg, memory-failure,
  oom-kill, secretmem, vmalloc, hugetlb, damon, and tools), and ocfs2"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  tools/testing/selftests/vm/split_huge_page_test.c: fix application of sizeof to pointer
  mm/damon/core-test: fix wrong expectations for 'damon_split_regions_of()'
  mm: khugepaged: skip huge page collapse for special files
  mm, thp: bail out early in collapse_file for writeback page
  mm/vmalloc: fix numa spreading for large hash tables
  mm/secretmem: avoid letting secretmem_users drop to zero
  ocfs2: fix race between searching chunks and release journal_head from buffer_head
  mm/oom_kill.c: prevent a race between process_mrelease and exit_mmap
  mm: filemap: check if THP has hwpoisoned subpage for PMD page fault
  mm: hwpoison: remove the unnecessary THP check
  memcg: page_alloc: skip bulk allocator for __GFP_ACCOUNT

Nathan reported that because KASAN_SHADOW_OFFSET was not defined in
Kconfig, it prevents asan-stack from getting disabled with clang even
when CONFIG_KASAN_STACK is disabled: fix this by defining the
corresponding config.
Reported-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Alexandre Ghiti <alexandre.ghiti@canonical.com>
Fixes: 8ad8b727 ("riscv: Add KASAN support")
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

When calling this function, all the shadow memory is already populated
with kasan_early_shadow_pte which has PAGE_KERNEL protection.
kasan_populate_early_shadow write-protects the mapping of the range
of addresses passed in argument in zero_pte_populate, which actually
write-protects all the shadow memory mapping since kasan_early_shadow_pte
is used for all the shadow memory at this point. And then when using
memblock API to populate the shadow memory, the first write access to the
kernel stack triggers a trap. This becomes visible with the next commit
that contains a fix for asan-stack.

We already manually populate all the shadow memory in kasan_early_init
and we write-protect kasan_early_shadow_pte at the end of kasan_init
which makes the calls to kasan_populate_early_shadow superfluous so
we can remove them.
Signed-off-by: Alexandre Ghiti <alexandre.ghiti@canonical.com>
Fixes: e178d670 ("riscv/kasan: add KASAN_VMALLOC support")
Fixes: 8ad8b727 ("riscv: Add KASAN support")
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

My snake instinct was on and I wrote "misssing" instead of "missing".
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

Some functions had kernel-doc that used a comma instead of a hash to
separate the function name from the one line description.

Also, the "ftrace_is_dead()" had an incomplete description.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

This reverts commit 8c945d32.

The kmaps in compression code are still needed and cause crashes on
32bit machines (ARM, x86). Reproducible eg. by running fstest btrfs/004
with enabled LZO or ZSTD compression.

The revert does not apply cleanly due to changes in a6e66e6f
("btrfs: rework lzo_decompress_bio() to make it subpage compatible")
that reworked the page iteration so the revert is done to be equivalent
to the original code.

Link: https://lore.kernel.org/all/CAJCQCtT+OuemovPO7GZk8Y8=qtOObr0XTDp8jh4OHD6y84AFxw@mail.gmail.com/
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=214839Tested-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

This reverts commit 696ab562.

The kmaps in compression code are still needed and cause crashes on
32bit machines (ARM, x86). Reproducible eg. by running fstest btrfs/004
with enabled LZO or ZSTD compression.

Link: https://lore.kernel.org/all/CAJCQCtT+OuemovPO7GZk8Y8=qtOObr0XTDp8jh4OHD6y84AFxw@mail.gmail.com/
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=214839Signed-off-by: David Sterba <dsterba@suse.com>

This reverts commit bbaf9715.

The kmaps in compression code are still needed and cause crashes on
32bit machines (ARM, x86). Reproducible eg. by running fstest btrfs/004
with enabled LZO or ZSTD compression.

Example stacktrace with ZSTD on a 32bit ARM machine:

  Unable to handle kernel NULL pointer dereference at virtual address 00000000
  pgd = c4159ed3
  [00000000] *pgd=00000000
  Internal error: Oops: 5 [#1] PREEMPT SMP ARM
  Modules linked in:
  CPU: 0 PID: 210 Comm: kworker/u2:3 Not tainted 5.14.0-rc79+ #12
  Hardware name: Allwinner sun4i/sun5i Families
  Workqueue: btrfs-delalloc btrfs_work_helper
  PC is at mmiocpy+0x48/0x330
  LR is at ZSTD_compressStream_generic+0x15c/0x28c

  (mmiocpy) from [<c0629648>] (ZSTD_compressStream_generic+0x15c/0x28c)
  (ZSTD_compressStream_generic) from [<c06297dc>] (ZSTD_compressStream+0x64/0xa0)
  (ZSTD_compressStream) from [<c049444c>] (zstd_compress_pages+0x170/0x488)
  (zstd_compress_pages) from [<c0496798>] (btrfs_compress_pages+0x124/0x12c)
  (btrfs_compress_pages) from [<c043c068>] (compress_file_range+0x3c0/0x834)
  (compress_file_range) from [<c043c4ec>] (async_cow_start+0x10/0x28)
  (async_cow_start) from [<c0475c3c>] (btrfs_work_helper+0x100/0x230)
  (btrfs_work_helper) from [<c014ef68>] (process_one_work+0x1b4/0x418)
  (process_one_work) from [<c014f210>] (worker_thread+0x44/0x524)
  (worker_thread) from [<c0156aa4>] (kthread+0x180/0x1b0)
  (kthread) from [<c0100150>]

Link: https://lore.kernel.org/all/CAJCQCtT+OuemovPO7GZk8Y8=qtOObr0XTDp8jh4OHD6y84AFxw@mail.gmail.com/
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=214839Signed-off-by: David Sterba <dsterba@suse.com>

The coccinelle check report:

  ./tools/testing/selftests/vm/split_huge_page_test.c:344:36-42:
  ERROR: application of sizeof to pointer

Use "strlen" to fix it.

Link: https://lkml.kernel.org/r/20211012030116.184027-1-davidcomponentone@gmail.comSigned-off-by: David Yang <davidcomponentone@gmail.com>
Reported-by: Zeal Robot <zealci@zte.com.cn>
Cc: Zi Yan <ziy@nvidia.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>

Kunit test cases for 'damon_split_regions_of()' expects the number of
regions after calling the function will be same to their request
('nr_sub').  However, the requested number is just an upper-limit,
because the function randomly decides the size of each sub-region.

This fixes the wrong expectation.

Link: https://lkml.kernel.org/r/20211028090628.14948-1-sj@kernel.org
Fixes: 17ccae8b ("mm/damon: add kunit tests")
Signed-off-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The read-only THP for filesystems will collapse THP for files opened
readonly and mapped with VM_EXEC.  The intended usecase is to avoid TLB
misses for large text segments.  But it doesn't restrict the file types
so a THP could be collapsed for a non-regular file, for example, block
device, if it is opened readonly and mapped with EXEC permission.  This
may cause bugs, like [1] and [2].

This is definitely not the intended usecase, so just collapse THP for
regular files in order to close the attack surface.

[shy828301@gmail.com: fix vm_file check [3]]

Link: https://lore.kernel.org/lkml/CACkBjsYwLYLRmX8GpsDpMthagWOjWWrNxqY6ZLNQVr6yx+f5vA@mail.gmail.com/ [1]
Link: https://lore.kernel.org/linux-mm/000000000000c6a82505ce284e4c@google.com/ [2]
Link: https://lkml.kernel.org/r/CAHbLzkqTW9U3VvTu1Ki5v_cLRC9gHW+znBukg_ycergE0JWj-A@mail.gmail.com [3]
Link: https://lkml.kernel.org/r/20211027195221.3825-1-shy828301@gmail.com
Fixes: 99cb0dbd ("mm,thp: add read-only THP support for (non-shmem) FS")
Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Yang Shi <shy828301@gmail.com>
Reported-by: Hao Sun <sunhao.th@gmail.com>
Reported-by: syzbot+aae069be1de40fb11825@syzkaller.appspotmail.com
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: Andrea Righi <andrea.righi@canonical.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Currently collapse_file does not explicitly check PG_writeback, instead,
page_has_private and try_to_release_page are used to filter writeback
pages.  This does not work for xfs with blocksize equal to or larger
than pagesize, because in such case xfs has no page->private.

This makes collapse_file bail out early for writeback page.  Otherwise,
xfs end_page_writeback will panic as follows.

  page:fffffe00201bcc80 refcount:0 mapcount:0 mapping:ffff0003f88c86a8 index:0x0 pfn:0x84ef32
  aops:xfs_address_space_operations [xfs] ino:30000b7 dentry name:"libtest.so"
  flags: 0x57fffe0000008027(locked|referenced|uptodate|active|writeback)
  raw: 57fffe0000008027 ffff80001b48bc28 ffff80001b48bc28 ffff0003f88c86a8
  raw: 0000000000000000 0000000000000000 00000000ffffffff ffff0000c3e9a000
  page dumped because: VM_BUG_ON_PAGE(((unsigned int) page_ref_count(page) + 127u <= 127u))
  page->mem_cgroup:ffff0000c3e9a000
  ------------[ cut here ]------------
  kernel BUG at include/linux/mm.h:1212!
  Internal error: Oops - BUG: 0 [#1] SMP
  Modules linked in:
  BUG: Bad page state in process khugepaged  pfn:84ef32
   xfs(E)
  page:fffffe00201bcc80 refcount:0 mapcount:0 mapping:0 index:0x0 pfn:0x84ef32
   libcrc32c(E) rfkill(E) aes_ce_blk(E) crypto_simd(E) ...
  CPU: 25 PID: 0 Comm: swapper/25 Kdump: loaded Tainted: ...
  pstate: 60400005 (nZCv daif +PAN -UAO -TCO BTYPE=--)
  Call trace:
    end_page_writeback+0x1c0/0x214
    iomap_finish_page_writeback+0x13c/0x204
    iomap_finish_ioend+0xe8/0x19c
    iomap_writepage_end_bio+0x38/0x50
    bio_endio+0x168/0x1ec
    blk_update_request+0x278/0x3f0
    blk_mq_end_request+0x34/0x15c
    virtblk_request_done+0x38/0x74 [virtio_blk]
    blk_done_softirq+0xc4/0x110
    __do_softirq+0x128/0x38c
    __irq_exit_rcu+0x118/0x150
    irq_exit+0x1c/0x30
    __handle_domain_irq+0x8c/0xf0
    gic_handle_irq+0x84/0x108
    el1_irq+0xcc/0x180
    arch_cpu_idle+0x18/0x40
    default_idle_call+0x4c/0x1a0
    cpuidle_idle_call+0x168/0x1e0
    do_idle+0xb4/0x104
    cpu_startup_entry+0x30/0x9c
    secondary_start_kernel+0x104/0x180
  Code: d4210000 b0006161 910c8021 94013f4d (d4210000)
  ---[ end trace 4a88c6a074082f8c ]---
  Kernel panic - not syncing: Oops - BUG: Fatal exception in interrupt

Link: https://lkml.kernel.org/r/20211022023052.33114-1-rongwei.wang@linux.alibaba.com
Fixes: 99cb0dbd ("mm,thp: add read-only THP support for (non-shmem) FS")
Signed-off-by: Rongwei Wang <rongwei.wang@linux.alibaba.com>
Signed-off-by: Xu Yu <xuyu@linux.alibaba.com>
Suggested-by: Yang Shi <shy828301@gmail.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Song Liu <song@kernel.org>
Cc: William Kucharski <william.kucharski@oracle.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Eric Dumazet reported a strange numa spreading info in [1], and found
commit 121e6f32 ("mm/vmalloc: hugepage vmalloc mappings") introduced
this issue [2].

Dig into the difference before and after this patch, page allocation has
some difference:

before:
  alloc_large_system_hash
    __vmalloc
      __vmalloc_node(..., NUMA_NO_NODE, ...)
        __vmalloc_node_range
          __vmalloc_area_node
            alloc_page /* because NUMA_NO_NODE, so choose alloc_page branch */
              alloc_pages_current
                alloc_page_interleave /* can be proved by print policy mode */

after:
  alloc_large_system_hash
    __vmalloc
      __vmalloc_node(..., NUMA_NO_NODE, ...)
        __vmalloc_node_range
          __vmalloc_area_node
            alloc_pages_node /* choose nid by nuam_mem_id() */
              __alloc_pages_node(nid, ....)

So after commit 121e6f32 ("mm/vmalloc: hugepage vmalloc mappings"),
it will allocate memory in current node instead of interleaving allocate
memory.

Link: https://lore.kernel.org/linux-mm/CANn89iL6AAyWhfxdHO+jaT075iOa3XcYn9k6JJc7JR2XYn6k_Q@mail.gmail.com/ [1]
Link: https://lore.kernel.org/linux-mm/CANn89iLofTR=AK-QOZY87RdUZENCZUT4O6a0hvhu3_EwRMerOg@mail.gmail.com/ [2]
Link: https://lkml.kernel.org/r/20211021080744.874701-2-chenwandun@huawei.com
Fixes: 121e6f32 ("mm/vmalloc: hugepage vmalloc mappings")
Signed-off-by: Chen Wandun <chenwandun@huawei.com>
Reported-by: Eric Dumazet <edumazet@google.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Hanjun Guo <guohanjun@huawei.com>
Cc: Uladzislau Rezki <urezki@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Quoting Dmitry:
 "refcount_inc() needs to be done before fd_install(). After
  fd_install() finishes, the fd can be used by userspace and
  we can have secret data in memory before the refcount_inc().

  A straightforward misuse where a user will predict the returned
  fd in another thread before the syscall returns and will use it
  to store secret data is somewhat dubious because such a user just
  shoots themself in the foot.

  But a more interesting misuse would be to close the predicted fd
  and decrement the refcount before the corresponding refcount_inc,
  this way one can briefly drop the refcount to zero while there are
  other users of secretmem."

Move fd_install() after refcount_inc().

Link: https://lkml.kernel.org/r/20211021154046.880251-1-keescook@chromium.org
Link: https://lore.kernel.org/lkml/CACT4Y+b1sW6-Hkn8HQYw_SsT7X3tp-CJNh2ci0wG3ZnQz9jjig@mail.gmail.com
Fixes: 9a436f8f ("PM: hibernate: disable when there are active secretmem users")
Signed-off-by: Kees Cook <keescook@chromium.org>
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Jordy Zomer <jordy@pwning.systems>
Cc: Mike Rapoport <rppt@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Encountered a race between ocfs2_test_bg_bit_allocatable() and
jbd2_journal_put_journal_head() resulting in the below vmcore.

  PID: 106879  TASK: ffff880244ba9c00  CPU: 2   COMMAND: "loop3"
  Call trace:
    panic
    oops_end
    no_context
    __bad_area_nosemaphore
    bad_area_nosemaphore
    __do_page_fault
    do_page_fault
    page_fault
      [exception RIP: ocfs2_block_group_find_clear_bits+316]
    ocfs2_block_group_find_clear_bits [ocfs2]
    ocfs2_cluster_group_search [ocfs2]
    ocfs2_search_chain [ocfs2]
    ocfs2_claim_suballoc_bits [ocfs2]
    __ocfs2_claim_clusters [ocfs2]
    ocfs2_claim_clusters [ocfs2]
    ocfs2_local_alloc_slide_window [ocfs2]
    ocfs2_reserve_local_alloc_bits [ocfs2]
    ocfs2_reserve_clusters_with_limit [ocfs2]
    ocfs2_reserve_clusters [ocfs2]
    ocfs2_lock_refcount_allocators [ocfs2]
    ocfs2_make_clusters_writable [ocfs2]
    ocfs2_replace_cow [ocfs2]
    ocfs2_refcount_cow [ocfs2]
    ocfs2_file_write_iter [ocfs2]
    lo_rw_aio
    loop_queue_work
    kthread_worker_fn
    kthread
    ret_from_fork

When ocfs2_test_bg_bit_allocatable() called bh2jh(bg_bh), the
bg_bh->b_private NULL as jbd2_journal_put_journal_head() raced and
released the jounal head from the buffer head.  Needed to take bit lock
for the bit 'BH_JournalHead' to fix this race.

Link: https://lkml.kernel.org/r/1634820718-6043-1-git-send-email-gautham.ananthakrishna@oracle.comSigned-off-by: Gautham Ananthakrishna <gautham.ananthakrishna@oracle.com>
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: <rajesh.sivaramasubramaniom@oracle.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Gang He <ghe@suse.com>
Cc: Jun Piao <piaojun@huawei.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Race between process_mrelease and exit_mmap, where free_pgtables is
called while __oom_reap_task_mm is in progress, leads to kernel crash
during pte_offset_map_lock call.  oom-reaper avoids this race by setting
MMF_OOM_VICTIM flag and causing exit_mmap to take and release
mmap_write_lock, blocking it until oom-reaper releases mmap_read_lock.

Reusing MMF_OOM_VICTIM for process_mrelease would be the simplest way to
fix this race, however that would be considered a hack.  Fix this race
by elevating mm->mm_users and preventing exit_mmap from executing until
process_mrelease is finished.  Patch slightly refactors the code to
adapt for a possible mmget_not_zero failure.

This fix has considerable negative impact on process_mrelease
performance and will likely need later optimization.

Link: https://lkml.kernel.org/r/20211022014658.263508-1-surenb@google.com
Fixes: 884a7e59 ("mm: introduce process_mrelease system call")
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Roman Gushchin <guro@fb.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Christian Brauner <christian@brauner.io>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Florian Weimer <fweimer@redhat.com>
Cc: Jan Engelhardt <jengelh@inai.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

When handling shmem page fault the THP with corrupted subpage could be
PMD mapped if certain conditions are satisfied.  But kernel is supposed
to send SIGBUS when trying to map hwpoisoned page.

There are two paths which may do PMD map: fault around and regular
fault.

Before commit f9ce0be7 ("mm: Cleanup faultaround and finish_fault()
codepaths") the thing was even worse in fault around path.  The THP
could be PMD mapped as long as the VMA fits regardless what subpage is
accessed and corrupted.  After this commit as long as head page is not
corrupted the THP could be PMD mapped.

In the regular fault path the THP could be PMD mapped as long as the
corrupted page is not accessed and the VMA fits.

This loophole could be fixed by iterating every subpage to check if any
of them is hwpoisoned or not, but it is somewhat costly in page fault
path.

So introduce a new page flag called HasHWPoisoned on the first tail
page.  It indicates the THP has hwpoisoned subpage(s).  It is set if any
subpage of THP is found hwpoisoned by memory failure and after the
refcount is bumped successfully, then cleared when the THP is freed or
split.

The soft offline path doesn't need this since soft offline handler just
marks a subpage hwpoisoned when the subpage is migrated successfully.
But shmem THP didn't get split then migrated at all.

Link: https://lkml.kernel.org/r/20211020210755.23964-3-shy828301@gmail.com
Fixes: 800d8c63 ("shmem: add huge pages support")
Signed-off-by: Yang Shi <shy828301@gmail.com>
Reviewed-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Suggested-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Peter Xu <peterx@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

When handling THP hwpoison checked if the THP is in allocation or free
stage since hwpoison may mistreat it as hugetlb page.  After commit
415c64c1 ("mm/memory-failure: split thp earlier in memory error
handling") the problem has been fixed, so this check is no longer
needed.  Remove it.  The side effect of the removal is hwpoison may
report unsplit THP instead of unknown error for shmem THP.  It seems not
like a big deal.

The following patch "mm: filemap: check if THP has hwpoisoned subpage
for PMD page fault" depends on this, which fixes shmem THP with
hwpoisoned subpage(s) are mapped PMD wrongly.  So this patch needs to be
backported to -stable as well.

Link: https://lkml.kernel.org/r/20211020210755.23964-2-shy828301@gmail.comSigned-off-by: Yang Shi <shy828301@gmail.com>
Suggested-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Peter Xu <peterx@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Commit 5c1f4e69 ("mm/vmalloc: switch to bulk allocator in
__vmalloc_area_node()") switched to bulk page allocator for order 0
allocation backing vmalloc.  However bulk page allocator does not
support __GFP_ACCOUNT allocations and there are several users of
kvmalloc(__GFP_ACCOUNT).

For now make __GFP_ACCOUNT allocations bypass bulk page allocator.  In
future if there is workload that can be significantly improved with the
bulk page allocator with __GFP_ACCCOUNT support, we can revisit the
decision.

Link: https://lkml.kernel.org/r/20211014151607.2171970-1-shakeelb@google.com
Fixes: 5c1f4e69 ("mm/vmalloc: switch to bulk allocator in __vmalloc_area_node()")
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Reported-by: Vasily Averin <vvs@virtuozzo.com>
Tested-by: Vasily Averin <vvs@virtuozzo.com>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Roman Gushchin <guro@fb.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull libnvdimm fix from Dan Williams:

 - Fix a regression introduced in v5.15-rc6 that caused nvdimm namespace
   shutdown to hang due to reworks in the block layer q_usage_count.

* tag 'libnvdimm-fixes-5.15-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  nvdimm/pmem: stop using q_usage_count as external pgmap refcount

The reset callback may clear the internal card detect interrupts, so
make sure to reenable them if needed.

Fixes: b4d86f37 ("mmc: renesas_sdhi: do hard reset if possible")
Reported-by: Biju Das <biju.das.jz@bp.renesas.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20211028195149.8003-1-wsa+renesas@sang-engineering.comSigned-off-by: Ulf Hansson <ulf.hansson@linaro.org>

Pull drm fixes from Dave Airlie:
 "Quiet but not too quiet, I blame Halloween.

  The first set of amdgpu fixes missed last week, hence why this has a
  few more of them, it's mostly display fixes for new GPUs and some
  debugfs OOB stuff.

  The i915 patches have one to remove a tracepoint possible issue before
  it's a real problem, the others around cflush and display are cc'ed to
  stable as well.

  Otherwise it's just a few misc fixes.

  Summary:

  MAINTAINERS:
   - Fix the path pattern

  ttm:
   - Fix fence leak in ttm_transfered_destroy.

  core:
   - Add GPD Win3 rotation quirk

  i915:
   - Remove unconditional clflushes
   - Fix oops on boot due to sync state on disabled DP encoders
   - Revert backend specific data added to tracepoints
   - Remove useless and incorrect memory frequence calculation

  panel:
   - Add quirk for Aya Neo 2021

  seltest:
   - Reset property count for each drm damage selftest so full run will
     work correctly.

  amdgpu:
   - Fix two potential out of bounds writes in debugfs
   - Fix revision handling for Yellow Carp
   - Display fixes for Yellow Carp
   - Display fixes for DCN 3.1"

* tag 'drm-fixes-2021-10-29' of git://anongit.freedesktop.org/drm/drm: (21 commits)
  MAINTAINERS: dri-devel is for all of drivers/gpu
  drm/i915: Revert 'guc_id' from i915_request tracepoint
  drm/amd/display: Fix deadlock when falling back to v2 from v3
  drm/amd/display: Fallback to clocks which meet requested voltage on DCN31
  drm/amdgpu: Fix even more out of bound writes from debugfs
  drm: panel-orientation-quirks: Add quirk for GPD Win3
  drm/i915/dp: Skip the HW readout of DPCD on disabled encoders
  drm/i915: Catch yet another unconditioal clflush
  drm/i915: Convert unconditional clflush to drm_clflush_virt_range()
  drm/i915/selftests: Properly reset mock object propers for each test
  drm: panel-orientation-quirks: Add quirk for Aya Neo 2021
  drm/ttm: fix memleak in ttm_transfered_destroy
  drm/amdgpu: support B0&B1 external revision id for yellow carp
  drm/amd/display: Moved dccg init to after bios golden init
  drm/amd/display: Increase watermark latencies for DCN3.1
  drm/amd/display: increase Z9 latency to workaround underflow in Z9
  drm/amd/display: Require immediate flip support for DCN3.1 planes
  drm/amd/display: Fix prefetch bandwidth calculation for DCN3.1
  drm/amd/display: Limit display scaling to up to true 4k for DCN 3.1
  drm/amdgpu: fix out of bounds write
  ...