linux.git/mm, branch v5.18 Clone of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git Merge tag 'mm-hotfixes-stable-2022-05-11' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm 2022-05-13T17:22:37+00:00 Linus Torvalds torvalds@linux-foundation.org 2022-05-13T17:22:37+00:00 364a453ab9123f493edfa246798ce9eeda452bdb Pull misc fixes from Andrew Morton: "Seven MM fixes, three of which address issues added in the most recent merge window, four of which are cc:stable. Three non-MM fixes, none very serious" [ And yes, that's a real pull request from Andrew, not me creating a branch from emailed patches. Woo-hoo! ] * tag 'mm-hotfixes-stable-2022-05-11' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: MAINTAINERS: add a mailing list for DAMON development selftests: vm: Makefile: rename TARGETS to VMTARGETS mm/kfence: reset PG_slab and memcg_data before freeing __kfence_pool mailmap: add entry for martyna.szapar-mudlaw@intel.com arm[64]/memremap: don't abuse pfn_valid() to ensure presence of linear map procfs: prevent unprivileged processes accessing fdinfo dir mm: mremap: fix sign for EFAULT error return value mm/hwpoison: use pr_err() instead of dump_page() in get_any_page() mm/huge_memory: do not overkill when splitting huge_zero_page Revert "mm/memory-failure.c: skip huge_zero_page in memory_failure()" 
Pull misc fixes from Andrew Morton:
 "Seven MM fixes, three of which address issues added in the most recent
  merge window, four of which are cc:stable.

  Three non-MM fixes, none very serious"

[ And yes, that's a real pull request from Andrew, not me creating a
  branch from emailed patches. Woo-hoo! ]

* tag 'mm-hotfixes-stable-2022-05-11' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
  MAINTAINERS: add a mailing list for DAMON development
  selftests: vm: Makefile: rename TARGETS to VMTARGETS
  mm/kfence: reset PG_slab and memcg_data before freeing __kfence_pool
  mailmap: add entry for martyna.szapar-mudlaw@intel.com
  arm[64]/memremap: don't abuse pfn_valid() to ensure presence of linear map
  procfs: prevent unprivileged processes accessing fdinfo dir
  mm: mremap: fix sign for EFAULT error return value
  mm/hwpoison: use pr_err() instead of dump_page() in get_any_page()
  mm/huge_memory: do not overkill when splitting huge_zero_page
  Revert "mm/memory-failure.c: skip huge_zero_page in memory_failure()"
mm/kfence: reset PG_slab and memcg_data before freeing __kfence_pool 2022-05-10T00:34:29+00:00 Hyeonggon Yoo 42.hyeyoo@gmail.com 2022-05-10T00:34:29+00:00 2839b0999c20c9f6bf353849c69370e121e2fa1a When kfence fails to initialize kfence pool, it frees the pool. But it does not reset memcg_data and PG_slab flag. Below is a BUG because of this. Let's fix it by resetting memcg_data and PG_slab flag before free. [ 0.089149] BUG: Bad page state in process swapper/0 pfn:3d8e06 [ 0.089149] page:ffffea46cf638180 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x3d8e06 [ 0.089150] memcg:ffffffff94a475d1 [ 0.089150] flags: 0x17ffffc0000200(slab|node=0|zone=2|lastcpupid=0x1fffff) [ 0.089151] raw: 0017ffffc0000200 ffffea46cf638188 ffffea46cf638188 0000000000000000 [ 0.089152] raw: 0000000000000000 0000000000000000 00000000ffffffff ffffffff94a475d1 [ 0.089152] page dumped because: page still charged to cgroup [ 0.089153] Modules linked in: [ 0.089153] CPU: 0 PID: 0 Comm: swapper/0 Tainted: G B W 5.18.0-rc1+ #965 [ 0.089154] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-2 04/01/2014 [ 0.089154] Call Trace: [ 0.089155] <TASK> [ 0.089155] dump_stack_lvl+0x49/0x5f [ 0.089157] dump_stack+0x10/0x12 [ 0.089158] bad_page.cold+0x63/0x94 [ 0.089159] check_free_page_bad+0x66/0x70 [ 0.089160] __free_pages_ok+0x423/0x530 [ 0.089161] __free_pages_core+0x8e/0xa0 [ 0.089162] memblock_free_pages+0x10/0x12 [ 0.089164] memblock_free_late+0x8f/0xb9 [ 0.089165] kfence_init+0x68/0x92 [ 0.089166] start_kernel+0x789/0x992 [ 0.089167] x86_64_start_reservations+0x24/0x26 [ 0.089168] x86_64_start_kernel+0xa9/0xaf [ 0.089170] secondary_startup_64_no_verify+0xd5/0xdb [ 0.089171] </TASK> Link: https://lkml.kernel.org/r/YnPG3pQrqfcgOlVa@hyeyoo Fixes: 0ce20dd84089 ("mm: add Kernel Electric-Fence infrastructure") Fixes: 8f0b36497303 ("mm: kfence: fix objcgs vector allocation") Signed-off-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Reviewed-by: Marco Elver <elver@google.com> Reviewed-by: Muchun Song <songmuchun@bytedance.com> Cc: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> 
When kfence fails to initialize kfence pool, it frees the pool.  But it
does not reset memcg_data and PG_slab flag.

Below is a BUG because of this. Let's fix it by resetting memcg_data
and PG_slab flag before free.

[    0.089149] BUG: Bad page state in process swapper/0  pfn:3d8e06
[    0.089149] page:ffffea46cf638180 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x3d8e06
[    0.089150] memcg:ffffffff94a475d1
[    0.089150] flags: 0x17ffffc0000200(slab|node=0|zone=2|lastcpupid=0x1fffff)
[    0.089151] raw: 0017ffffc0000200 ffffea46cf638188 ffffea46cf638188 0000000000000000
[    0.089152] raw: 0000000000000000 0000000000000000 00000000ffffffff ffffffff94a475d1
[    0.089152] page dumped because: page still charged to cgroup
[    0.089153] Modules linked in:
[    0.089153] CPU: 0 PID: 0 Comm: swapper/0 Tainted: G    B   W         5.18.0-rc1+ #965
[    0.089154] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-2 04/01/2014
[    0.089154] Call Trace:
[    0.089155]  <TASK>
[    0.089155]  dump_stack_lvl+0x49/0x5f
[    0.089157]  dump_stack+0x10/0x12
[    0.089158]  bad_page.cold+0x63/0x94
[    0.089159]  check_free_page_bad+0x66/0x70
[    0.089160]  __free_pages_ok+0x423/0x530
[    0.089161]  __free_pages_core+0x8e/0xa0
[    0.089162]  memblock_free_pages+0x10/0x12
[    0.089164]  memblock_free_late+0x8f/0xb9
[    0.089165]  kfence_init+0x68/0x92
[    0.089166]  start_kernel+0x789/0x992
[    0.089167]  x86_64_start_reservations+0x24/0x26
[    0.089168]  x86_64_start_kernel+0xa9/0xaf
[    0.089170]  secondary_startup_64_no_verify+0xd5/0xdb
[    0.089171]  </TASK>

Link: https://lkml.kernel.org/r/YnPG3pQrqfcgOlVa@hyeyoo
Fixes: 0ce20dd84089 ("mm: add Kernel Electric-Fence infrastructure")
Fixes: 8f0b36497303 ("mm: kfence: fix objcgs vector allocation")
Signed-off-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Reviewed-by: Marco Elver <elver@google.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
mm: mremap: fix sign for EFAULT error return value 2022-05-10T00:34:28+00:00 Niels Dossche dossche.niels@gmail.com 2022-05-10T00:34:28+00:00 7d1e6496616275f3830e2f2f91fa69a66953e95b The mremap syscall is supposed to return a pointer to the new virtual memory area on success, and a negative value of the error code in case of failure. Currently, EFAULT is returned when the VMA is not found, instead of -EFAULT. The users of this syscall will therefore believe the syscall succeeded in case the VMA didn't exist, as it returns a pointer to address 0xe (0xe being the value of EFAULT). Fix the sign of the error value. Link: https://lkml.kernel.org/r/20220427224439.23828-2-dossche.niels@gmail.com Fixes: 550a7d60bd5e ("mm, hugepages: add mremap() support for hugepage backed vma") Signed-off-by: Niels Dossche <dossche.niels@gmail.com> Cc: Mina Almasry <almasrymina@google.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> 
The mremap syscall is supposed to return a pointer to the new virtual
memory area on success, and a negative value of the error code in case of
failure.  Currently, EFAULT is returned when the VMA is not found, instead
of -EFAULT.  The users of this syscall will therefore believe the syscall
succeeded in case the VMA didn't exist, as it returns a pointer to address
0xe (0xe being the value of EFAULT).  Fix the sign of the error value.

Link: https://lkml.kernel.org/r/20220427224439.23828-2-dossche.niels@gmail.com
Fixes: 550a7d60bd5e ("mm, hugepages: add mremap() support for hugepage backed vma")
Signed-off-by: Niels Dossche <dossche.niels@gmail.com>
Cc: Mina Almasry <almasrymina@google.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
mm/readahead: Fix readahead with large folios 2022-05-05T04:47:29+00:00 Matthew Wilcox (Oracle) willy@infradead.org 2022-04-27T21:01:28+00:00 b9ff43dd27434dbd850b908e2e0e1f6e794efd9b Reading 100KB chunks from a big file (eg dd bs=100K) leads to poor readahead behaviour. Studying the traces in detail, I noticed two problems. The first is that we were setting the readahead flag on the folio which contains the last byte read from the block. This is wrong because we will trigger readahead at the end of the read without waiting to see if a subsequent read is going to use the pages we just read. Instead, we need to set the readahead flag on the first folio _after_ the one which contains the last byte that we're reading. The second is that we were looking for the index of the folio with the readahead flag set to exactly match the start + size - async_size. If we've rounded this, either down (as previously) or up (as now), we'll think we hit a folio marked as readahead by a different read, and try to read the wrong pages. So round the expected index to the order of the folio we hit. Reported-by: Guo Xuenan <guoxuenan@huawei.com> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> 
Reading 100KB chunks from a big file (eg dd bs=100K) leads to poor
readahead behaviour.  Studying the traces in detail, I noticed two
problems.

The first is that we were setting the readahead flag on the folio which
contains the last byte read from the block.  This is wrong because we
will trigger readahead at the end of the read without waiting to see
if a subsequent read is going to use the pages we just read.  Instead,
we need to set the readahead flag on the first folio _after_ the one
which contains the last byte that we're reading.

The second is that we were looking for the index of the folio with the
readahead flag set to exactly match the start + size - async_size.
If we've rounded this, either down (as previously) or up (as now),
we'll think we hit a folio marked as readahead by a different read,
and try to read the wrong pages.  So round the expected index to the
order of the folio we hit.

Reported-by: Guo Xuenan <guoxuenan@huawei.com>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
mm/hwpoison: use pr_err() instead of dump_page() in get_any_page() 2022-04-29T06:14:44+00:00 Naoya Horiguchi naoya.horiguchi@nec.com 2022-04-29T06:14:44+00:00 1825b93b626e99eb9a0f9f50342c7b2fa201b387 The following VM_BUG_ON_FOLIO() is triggered when memory error event happens on the (thp/folio) pages which are about to be freed: [ 1160.232771] page:00000000b36a8a0f refcount:1 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x16a000 [ 1160.236916] page:00000000b36a8a0f refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x16a000 [ 1160.240684] flags: 0x57ffffc0800000(hwpoison|node=1|zone=2|lastcpupid=0x1fffff) [ 1160.243458] raw: 0057ffffc0800000 dead000000000100 dead000000000122 0000000000000000 [ 1160.246268] raw: 0000000000000001 0000000000000000 00000000ffffffff 0000000000000000 [ 1160.249197] page dumped because: VM_BUG_ON_FOLIO(!folio_test_large(folio)) [ 1160.251815] ------------[ cut here ]------------ [ 1160.253438] kernel BUG at include/linux/mm.h:788! [ 1160.256162] invalid opcode: 0000 [#1] PREEMPT SMP PTI [ 1160.258172] CPU: 2 PID: 115368 Comm: mceinj.sh Tainted: G E 5.18.0-rc1-v5.18-rc1-220404-2353-005-g83111+ #3 [ 1160.262049] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1.fc35 04/01/2014 [ 1160.265103] RIP: 0010:dump_page.cold+0x27e/0x2bd [ 1160.266757] Code: fe ff ff 48 c7 c6 81 f1 5a 98 e9 4c fe ff ff 48 c7 c6 a1 95 59 98 e9 40 fe ff ff 48 c7 c6 50 bf 5a 98 48 89 ef e8 9d 04 6d ff <0f> 0b 41 f7 c4 ff 0f 00 00 0f 85 9f fd ff ff 49 8b 04 24 a9 00 00 [ 1160.273180] RSP: 0018:ffffaa2c4d59fd18 EFLAGS: 00010292 [ 1160.274969] RAX: 000000000000003e RBX: 0000000000000001 RCX: 0000000000000000 [ 1160.277263] RDX: 0000000000000001 RSI: ffffffff985995a1 RDI: 00000000ffffffff [ 1160.279571] RBP: ffffdc9c45a80000 R08: 0000000000000000 R09: 00000000ffffdfff [ 1160.281794] R10: ffffaa2c4d59fb08 R11: ffffffff98940d08 R12: ffffdc9c45a80000 [ 1160.283920] R13: ffffffff985b6f94 R14: 0000000000000000 R15: ffffdc9c45a80000 [ 1160.286641] FS: 00007eff54ce1740(0000) GS:ffff99c67bd00000(0000) knlGS:0000000000000000 [ 1160.289498] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 1160.291106] CR2: 00005628381a5f68 CR3: 0000000104712003 CR4: 0000000000170ee0 [ 1160.293031] Call Trace: [ 1160.293724] <TASK> [ 1160.294334] get_hwpoison_page+0x47d/0x570 [ 1160.295474] memory_failure+0x106/0xaa0 [ 1160.296474] ? security_capable+0x36/0x50 [ 1160.297524] hard_offline_page_store+0x43/0x80 [ 1160.298684] kernfs_fop_write_iter+0x11c/0x1b0 [ 1160.299829] new_sync_write+0xf9/0x160 [ 1160.300810] vfs_write+0x209/0x290 [ 1160.301835] ksys_write+0x4f/0xc0 [ 1160.302718] do_syscall_64+0x3b/0x90 [ 1160.303664] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 1160.304981] RIP: 0033:0x7eff54b018b7 As shown in the RIP address, this VM_BUG_ON in folio_entire_mapcount() is called from dump_page("hwpoison: unhandlable page") in get_any_page(). The below explains the mechanism of the race: CPU 0 CPU 1 memory_failure get_hwpoison_page get_any_page dump_page compound = PageCompound free_pages_prepare page->flags &= ~PAGE_FLAGS_CHECK_AT_PREP folio_entire_mapcount VM_BUG_ON_FOLIO(!folio_test_large(folio)) So replace dump_page() with safer one, pr_err(). Link: https://lkml.kernel.org/r/20220427053220.719866-1-naoya.horiguchi@linux.dev Fixes: 74e8ee4708a8 ("mm: Turn head_compound_mapcount() into folio_entire_mapcount()") Signed-off-by: Naoya Horiguchi <naoya.horiguchi@nec.com> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: Miaohe Lin <linmiaohe@huawei.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Christoph Hellwig <hch@infradead.org> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: William Kucharski <william.kucharski@oracle.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> 
The following VM_BUG_ON_FOLIO() is triggered when memory error event
happens on the (thp/folio) pages which are about to be freed:

  [ 1160.232771] page:00000000b36a8a0f refcount:1 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x16a000
  [ 1160.236916] page:00000000b36a8a0f refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x16a000
  [ 1160.240684] flags: 0x57ffffc0800000(hwpoison|node=1|zone=2|lastcpupid=0x1fffff)
  [ 1160.243458] raw: 0057ffffc0800000 dead000000000100 dead000000000122 0000000000000000
  [ 1160.246268] raw: 0000000000000001 0000000000000000 00000000ffffffff 0000000000000000
  [ 1160.249197] page dumped because: VM_BUG_ON_FOLIO(!folio_test_large(folio))
  [ 1160.251815] ------------[ cut here ]------------
  [ 1160.253438] kernel BUG at include/linux/mm.h:788!
  [ 1160.256162] invalid opcode: 0000 [#1] PREEMPT SMP PTI
  [ 1160.258172] CPU: 2 PID: 115368 Comm: mceinj.sh Tainted: G            E     5.18.0-rc1-v5.18-rc1-220404-2353-005-g83111+ #3
  [ 1160.262049] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1.fc35 04/01/2014
  [ 1160.265103] RIP: 0010:dump_page.cold+0x27e/0x2bd
  [ 1160.266757] Code: fe ff ff 48 c7 c6 81 f1 5a 98 e9 4c fe ff ff 48 c7 c6 a1 95 59 98 e9 40 fe ff ff 48 c7 c6 50 bf 5a 98 48 89 ef e8 9d 04 6d ff <0f> 0b 41 f7 c4 ff 0f 00 00 0f 85 9f fd ff ff 49 8b 04 24 a9 00 00
  [ 1160.273180] RSP: 0018:ffffaa2c4d59fd18 EFLAGS: 00010292
  [ 1160.274969] RAX: 000000000000003e RBX: 0000000000000001 RCX: 0000000000000000
  [ 1160.277263] RDX: 0000000000000001 RSI: ffffffff985995a1 RDI: 00000000ffffffff
  [ 1160.279571] RBP: ffffdc9c45a80000 R08: 0000000000000000 R09: 00000000ffffdfff
  [ 1160.281794] R10: ffffaa2c4d59fb08 R11: ffffffff98940d08 R12: ffffdc9c45a80000
  [ 1160.283920] R13: ffffffff985b6f94 R14: 0000000000000000 R15: ffffdc9c45a80000
  [ 1160.286641] FS:  00007eff54ce1740(0000) GS:ffff99c67bd00000(0000) knlGS:0000000000000000
  [ 1160.289498] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  [ 1160.291106] CR2: 00005628381a5f68 CR3: 0000000104712003 CR4: 0000000000170ee0
  [ 1160.293031] Call Trace:
  [ 1160.293724]  <TASK>
  [ 1160.294334]  get_hwpoison_page+0x47d/0x570
  [ 1160.295474]  memory_failure+0x106/0xaa0
  [ 1160.296474]  ? security_capable+0x36/0x50
  [ 1160.297524]  hard_offline_page_store+0x43/0x80
  [ 1160.298684]  kernfs_fop_write_iter+0x11c/0x1b0
  [ 1160.299829]  new_sync_write+0xf9/0x160
  [ 1160.300810]  vfs_write+0x209/0x290
  [ 1160.301835]  ksys_write+0x4f/0xc0
  [ 1160.302718]  do_syscall_64+0x3b/0x90
  [ 1160.303664]  entry_SYSCALL_64_after_hwframe+0x44/0xae
  [ 1160.304981] RIP: 0033:0x7eff54b018b7

As shown in the RIP address, this VM_BUG_ON in folio_entire_mapcount() is
called from dump_page("hwpoison: unhandlable page") in get_any_page().
The below explains the mechanism of the race:

  CPU 0                                       CPU 1

    memory_failure
      get_hwpoison_page
        get_any_page
          dump_page
            compound = PageCompound
                                                free_pages_prepare
                                                  page->flags &= ~PAGE_FLAGS_CHECK_AT_PREP
            folio_entire_mapcount
              VM_BUG_ON_FOLIO(!folio_test_large(folio))

So replace dump_page() with safer one, pr_err().

Link: https://lkml.kernel.org/r/20220427053220.719866-1-naoya.horiguchi@linux.dev
Fixes: 74e8ee4708a8 ("mm: Turn head_compound_mapcount() into folio_entire_mapcount()")
Signed-off-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: William Kucharski <william.kucharski@oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
mm/huge_memory: do not overkill when splitting huge_zero_page 2022-04-29T06:14:43+00:00 Xu Yu xuyu@linux.alibaba.com 2022-04-29T06:14:43+00:00 478d134e9506c7e9bfe2830ed03dd85e97966313 Kernel panic when injecting memory_failure for the global huge_zero_page, when CONFIG_DEBUG_VM is enabled, as follows. Injecting memory failure for pfn 0x109ff9 at process virtual address 0x20ff9000 page:00000000fb053fc3 refcount:2 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x109e00 head:00000000fb053fc3 order:9 compound_mapcount:0 compound_pincount:0 flags: 0x17fffc000010001(locked|head|node=0|zone=2|lastcpupid=0x1ffff) raw: 017fffc000010001 0000000000000000 dead000000000122 0000000000000000 raw: 0000000000000000 0000000000000000 00000002ffffffff 0000000000000000 page dumped because: VM_BUG_ON_PAGE(is_huge_zero_page(head)) ------------[ cut here ]------------ kernel BUG at mm/huge_memory.c:2499! invalid opcode: 0000 [#1] PREEMPT SMP PTI CPU: 6 PID: 553 Comm: split_bug Not tainted 5.18.0-rc1+ #11 Hardware name: Alibaba Cloud Alibaba Cloud ECS, BIOS 3288b3c 04/01/2014 RIP: 0010:split_huge_page_to_list+0x66a/0x880 Code: 84 9b fb ff ff 48 8b 7c 24 08 31 f6 e8 9f 5d 2a 00 b8 b8 02 00 00 e9 e8 fb ff ff 48 c7 c6 e8 47 3c 82 4c b RSP: 0018:ffffc90000dcbdf8 EFLAGS: 00010246 RAX: 000000000000003c RBX: 0000000000000001 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff823e4c4f RDI: 00000000ffffffff RBP: ffff88843fffdb40 R08: 0000000000000000 R09: 00000000fffeffff R10: ffffc90000dcbc48 R11: ffffffff82d68448 R12: ffffea0004278000 R13: ffffffff823c6203 R14: 0000000000109ff9 R15: ffffea000427fe40 FS: 00007fc375a26740(0000) GS:ffff88842fd80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fc3757c9290 CR3: 0000000102174006 CR4: 00000000003706e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: try_to_split_thp_page+0x3a/0x130 memory_failure+0x128/0x800 madvise_inject_error.cold+0x8b/0xa1 __x64_sys_madvise+0x54/0x60 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7fc3754f8bf9 Code: 01 00 48 81 c4 80 00 00 00 e9 f1 fe ff ff 0f 1f 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 8 RSP: 002b:00007ffeda93a1d8 EFLAGS: 00000217 ORIG_RAX: 000000000000001c RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fc3754f8bf9 RDX: 0000000000000064 RSI: 0000000000003000 RDI: 0000000020ff9000 RBP: 00007ffeda93a200 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000217 R12: 0000000000400490 R13: 00007ffeda93a2e0 R14: 0000000000000000 R15: 0000000000000000 We think that raising BUG is overkilling for splitting huge_zero_page, the huge_zero_page can't be met from normal paths other than memory failure, but memory failure is a valid caller. So we tend to replace the BUG to WARN + returning -EBUSY, and thus the panic above won't happen again. Link: https://lkml.kernel.org/r/f35f8b97377d5d3ede1bc5ac3114da888c57cbce.1651052574.git.xuyu@linux.alibaba.com Fixes: d173d5417fb6 ("mm/memory-failure.c: skip huge_zero_page in memory_failure()") Fixes: 6a46079cf57a ("HWPOISON: The high level memory error handler in the VM v7") Signed-off-by: Xu Yu <xuyu@linux.alibaba.com> Suggested-by: Yang Shi <shy828301@gmail.com> Reported-by: kernel test robot <lkp@intel.com> Reviewed-by: Naoya Horiguchi <naoya.horiguchi@nec.com> Reviewed-by: Yang Shi <shy828301@gmail.com> Reviewed-by: Miaohe Lin <linmiaohe@huawei.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> 
Kernel panic when injecting memory_failure for the global huge_zero_page,
when CONFIG_DEBUG_VM is enabled, as follows.

  Injecting memory failure for pfn 0x109ff9 at process virtual address 0x20ff9000
  page:00000000fb053fc3 refcount:2 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x109e00
  head:00000000fb053fc3 order:9 compound_mapcount:0 compound_pincount:0
  flags: 0x17fffc000010001(locked|head|node=0|zone=2|lastcpupid=0x1ffff)
  raw: 017fffc000010001 0000000000000000 dead000000000122 0000000000000000
  raw: 0000000000000000 0000000000000000 00000002ffffffff 0000000000000000
  page dumped because: VM_BUG_ON_PAGE(is_huge_zero_page(head))
  ------------[ cut here ]------------
  kernel BUG at mm/huge_memory.c:2499!
  invalid opcode: 0000 [#1] PREEMPT SMP PTI
  CPU: 6 PID: 553 Comm: split_bug Not tainted 5.18.0-rc1+ #11
  Hardware name: Alibaba Cloud Alibaba Cloud ECS, BIOS 3288b3c 04/01/2014
  RIP: 0010:split_huge_page_to_list+0x66a/0x880
  Code: 84 9b fb ff ff 48 8b 7c 24 08 31 f6 e8 9f 5d 2a 00 b8 b8 02 00 00 e9 e8 fb ff ff 48 c7 c6 e8 47 3c 82 4c b
  RSP: 0018:ffffc90000dcbdf8 EFLAGS: 00010246
  RAX: 000000000000003c RBX: 0000000000000001 RCX: 0000000000000000
  RDX: 0000000000000000 RSI: ffffffff823e4c4f RDI: 00000000ffffffff
  RBP: ffff88843fffdb40 R08: 0000000000000000 R09: 00000000fffeffff
  R10: ffffc90000dcbc48 R11: ffffffff82d68448 R12: ffffea0004278000
  R13: ffffffff823c6203 R14: 0000000000109ff9 R15: ffffea000427fe40
  FS:  00007fc375a26740(0000) GS:ffff88842fd80000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 00007fc3757c9290 CR3: 0000000102174006 CR4: 00000000003706e0
  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
  Call Trace:
  try_to_split_thp_page+0x3a/0x130
  memory_failure+0x128/0x800
  madvise_inject_error.cold+0x8b/0xa1
  __x64_sys_madvise+0x54/0x60
  do_syscall_64+0x35/0x80
  entry_SYSCALL_64_after_hwframe+0x44/0xae
  RIP: 0033:0x7fc3754f8bf9
  Code: 01 00 48 81 c4 80 00 00 00 e9 f1 fe ff ff 0f 1f 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 8
  RSP: 002b:00007ffeda93a1d8 EFLAGS: 00000217 ORIG_RAX: 000000000000001c
  RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fc3754f8bf9
  RDX: 0000000000000064 RSI: 0000000000003000 RDI: 0000000020ff9000
  RBP: 00007ffeda93a200 R08: 0000000000000000 R09: 0000000000000000
  R10: 00000000ffffffff R11: 0000000000000217 R12: 0000000000400490
  R13: 00007ffeda93a2e0 R14: 0000000000000000 R15: 0000000000000000

We think that raising BUG is overkilling for splitting huge_zero_page, the
huge_zero_page can't be met from normal paths other than memory failure,
but memory failure is a valid caller.  So we tend to replace the BUG to
WARN + returning -EBUSY, and thus the panic above won't happen again.

Link: https://lkml.kernel.org/r/f35f8b97377d5d3ede1bc5ac3114da888c57cbce.1651052574.git.xuyu@linux.alibaba.com
Fixes: d173d5417fb6 ("mm/memory-failure.c: skip huge_zero_page in memory_failure()")
Fixes: 6a46079cf57a ("HWPOISON: The high level memory error handler in the VM v7")
Signed-off-by: Xu Yu <xuyu@linux.alibaba.com>
Suggested-by: Yang Shi <shy828301@gmail.com>
Reported-by: kernel test robot <lkp@intel.com>
Reviewed-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Revert "mm/memory-failure.c: skip huge_zero_page in memory_failure()" 2022-04-29T06:14:43+00:00 Xu Yu xuyu@linux.alibaba.com 2022-04-29T06:14:43+00:00 b4e61fc031b11dd807dffc46cebbf0e25966d3d1 Patch series "mm/memory-failure: rework fix on huge_zero_page splitting". This patch (of 2): This reverts commit d173d5417fb67411e623d394aab986d847e47dad. The commit d173d5417fb6 ("mm/memory-failure.c: skip huge_zero_page in memory_failure()") explicitly skips huge_zero_page in memory_failure(), in order to avoid triggering VM_BUG_ON_PAGE on huge_zero_page in split_huge_page_to_list(). This works, but Yang Shi thinks that, Raising BUG is overkilling for splitting huge_zero_page. The huge_zero_page can't be met from normal paths other than memory failure, but memory failure is a valid caller. So I tend to replace the BUG to WARN + returning -EBUSY. If we don't care about the reason code in memory failure, we don't have to touch memory failure. And for the issue that huge_zero_page will be set PG_has_hwpoisoned, Yang Shi comments that, The anonymous page fault doesn't check if the page is poisoned or not since it typically gets a fresh allocated page and assumes the poisoned page (isolated successfully) can't be reallocated again. But huge zero page and base zero page are reused every time. So no matter what fix we pick, the issue is always there. Finally, Yang, David, Anshuman and Naoya all agree to fix the bug, i.e., to split huge_zero_page, in split_huge_page_to_list(). This reverts the commit d173d5417fb6 ("mm/memory-failure.c: skip huge_zero_page in memory_failure()"), and the original bug will be fixed by the next patch. Link: https://lkml.kernel.org/r/872cefb182ba1dd686b0e7db1e6b2ebe5a4fff87.1651039624.git.xuyu@linux.alibaba.com Fixes: d173d5417fb6 ("mm/memory-failure.c: skip huge_zero_page in memory_failure()") Fixes: 6a46079cf57a ("HWPOISON: The high level memory error handler in the VM v7") Signed-off-by: Xu Yu <xuyu@linux.alibaba.com> Suggested-by: Yang Shi <shy828301@gmail.com> Reviewed-by: Yang Shi <shy828301@gmail.com> Reviewed-by: Miaohe Lin <linmiaohe@huawei.com> Cc: Naoya Horiguchi <naoya.horiguchi@nec.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> 
Patch series "mm/memory-failure: rework fix on huge_zero_page splitting".


This patch (of 2):

This reverts commit d173d5417fb67411e623d394aab986d847e47dad.

The commit d173d5417fb6 ("mm/memory-failure.c: skip huge_zero_page in
memory_failure()") explicitly skips huge_zero_page in memory_failure(), in
order to avoid triggering VM_BUG_ON_PAGE on huge_zero_page in
split_huge_page_to_list().

This works, but Yang Shi thinks that,

    Raising BUG is overkilling for splitting huge_zero_page. The
    huge_zero_page can't be met from normal paths other than memory
    failure, but memory failure is a valid caller. So I tend to replace
    the BUG to WARN + returning -EBUSY. If we don't care about the
    reason code in memory failure, we don't have to touch memory
    failure.

And for the issue that huge_zero_page will be set PG_has_hwpoisoned,
Yang Shi comments that,

    The anonymous page fault doesn't check if the page is poisoned or
    not since it typically gets a fresh allocated page and assumes the
    poisoned page (isolated successfully) can't be reallocated again.
    But huge zero page and base zero page are reused every time. So no
    matter what fix we pick, the issue is always there.

Finally, Yang, David, Anshuman and Naoya all agree to fix the bug, i.e.,
to split huge_zero_page, in split_huge_page_to_list().

This reverts the commit d173d5417fb6 ("mm/memory-failure.c: skip
huge_zero_page in memory_failure()"), and the original bug will be fixed
by the next patch.

Link: https://lkml.kernel.org/r/872cefb182ba1dd686b0e7db1e6b2ebe5a4fff87.1651039624.git.xuyu@linux.alibaba.com
Fixes: d173d5417fb6 ("mm/memory-failure.c: skip huge_zero_page in memory_failure()")
Fixes: 6a46079cf57a ("HWPOISON: The high level memory error handler in the VM v7")
Signed-off-by: Xu Yu <xuyu@linux.alibaba.com>
Suggested-by: Yang Shi <shy828301@gmail.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
kasan: prevent cpu_quarantine corruption when CPU offline and cache shrink occur at same time 2022-04-27T20:28:48+00:00 Zqiang qiang1.zhang@intel.com 2022-04-27T19:41:56+00:00 31fa985b4196f8a66f027672e9bf2b81fea0417c kasan_quarantine_remove_cache() is called in kmem_cache_shrink()/ destroy(). The kasan_quarantine_remove_cache() call is protected by cpuslock in kmem_cache_destroy() to ensure serialization with kasan_cpu_offline(). However the kasan_quarantine_remove_cache() call is not protected by cpuslock in kmem_cache_shrink(). When a CPU is going offline and cache shrink occurs at same time, the cpu_quarantine may be corrupted by interrupt (per_cpu_remove_cache operation). So add a cpu_quarantine offline flags check in per_cpu_remove_cache(). [akpm@linux-foundation.org: add comment, per Zqiang] Link: https://lkml.kernel.org/r/20220414025925.2423818-1-qiang1.zhang@intel.com Signed-off-by: Zqiang <qiang1.zhang@intel.com> Reviewed-by: Dmitry Vyukov <dvyukov@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> 
kasan_quarantine_remove_cache() is called in kmem_cache_shrink()/
destroy().  The kasan_quarantine_remove_cache() call is protected by
cpuslock in kmem_cache_destroy() to ensure serialization with
kasan_cpu_offline().

However the kasan_quarantine_remove_cache() call is not protected by
cpuslock in kmem_cache_shrink().  When a CPU is going offline and cache
shrink occurs at same time, the cpu_quarantine may be corrupted by
interrupt (per_cpu_remove_cache operation).

So add a cpu_quarantine offline flags check in per_cpu_remove_cache().

[akpm@linux-foundation.org: add comment, per Zqiang]

Link: https://lkml.kernel.org/r/20220414025925.2423818-1-qiang1.zhang@intel.com
Signed-off-by: Zqiang <qiang1.zhang@intel.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
no-MMU: expose vmalloc_huge() for alloc_large_system_hash() 2022-04-25T17:11:49+00:00 Linus Torvalds torvalds@linux-foundation.org 2022-04-25T08:28:01+00:00 0fc74d820a012550be006ba82dd8f1e3fe6fa9f7 It turns out that for the CONFIG_MMU=n builds, vmalloc_huge() was never defined, since it's defined in mm/vmalloc.c, which doesn't get built for the no-MMU configurations. Just implement the trivial wrapper for the no-MMU case too. In fact, just make it an alias to the existing __vmalloc() function that has the same signature. Link: https://lore.kernel.org/all/CAMuHMdVdx2V1uhv_152Sw3_z2xE0spiaWp1d6Ko8-rYmAxUBAg@mail.gmail.com/ Link: https://lore.kernel.org/all/CA+G9fYscb1y4a17Sf5G_Aibt+WuSf-ks_Qjw9tYFy=A4sjCEug@mail.gmail.com/ Link: https://lore.kernel.org/all/20220425150356.GA4138752@roeck-us.net/ Reported-and-tested-by: Linux Kernel Functional Testing <lkft@linaro.org> Reported-and-tested-by: Geert Uytterhoeven <geert@linux-m68k.org> Reported-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com> Reported-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> 
It turns out that for the CONFIG_MMU=n builds, vmalloc_huge() was never
defined, since it's defined in mm/vmalloc.c, which doesn't get built for
the no-MMU configurations.

Just implement the trivial wrapper for the no-MMU case too.  In fact,
just make it an alias to the existing __vmalloc() function that has the
same signature.

Link: https://lore.kernel.org/all/CAMuHMdVdx2V1uhv_152Sw3_z2xE0spiaWp1d6Ko8-rYmAxUBAg@mail.gmail.com/
Link: https://lore.kernel.org/all/CA+G9fYscb1y4a17Sf5G_Aibt+WuSf-ks_Qjw9tYFy=A4sjCEug@mail.gmail.com/
Link: https://lore.kernel.org/all/20220425150356.GA4138752@roeck-us.net/
Reported-and-tested-by: Linux Kernel Functional Testing <lkft@linaro.org>
Reported-and-tested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reported-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Reported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
kvmalloc: use vmalloc_huge for vmalloc allocations 2022-04-24T17:05:38+00:00 Linus Torvalds torvalds@linux-foundation.org 2022-04-22T18:41:38+00:00 9becb688913023124464c5463b4389b3b293f0e7 Since commit 559089e0a93d ("vmalloc: replace VM_NO_HUGE_VMAP with VM_ALLOW_HUGE_VMAP"), the use of hugepage mappings for vmalloc is an opt-in strategy, because it caused a number of problems that weren't noticed until x86 enabled it too. One of the issues was fixed by Nick Piggin in commit 3b8000ae185c ("mm/vmalloc: huge vmalloc backing pages should be split rather than compound"), but I'm still worried about page protection issues, and VM_FLUSH_RESET_PERMS in particular. However, like the hash table allocation case (commit f2edd118d02d: "page_alloc: use vmalloc_huge for large system hash"), the use of kvmalloc() should be safe from any such games, since the returned pointer might be a SLUB allocation, and as such no user should reasonably be using it in any odd ways. We also know that the allocations are fairly large, since it falls back to the vmalloc case only when a kmalloc() fails. So using a hugepage mapping seems both safe and relevant. This patch does show a weakness in the opt-in strategy: since the opt-in flag is in the 'vm_flags', not the usual gfp_t allocation flags, very few of the usual interfaces actually expose it. That's not much of an issue in this case that already used one of the fairly specialized low-level vmalloc interfaces for the allocation, but for a lot of other vmalloc() users that might want to opt in, it's going to be very inconvenient. We'll either have to fix any compatibility problems, or expose it in the gfp flags (__GFP_COMP would have made a lot of sense) to allow normal vmalloc() users to use hugepage mappings. That said, the cases that really matter were probably already taken care of by the hash tabel allocation. Link: https://lore.kernel.org/all/20220415164413.2727220-1-song@kernel.org/ Link: https://lore.kernel.org/all/CAHk-=whao=iosX1s5Z4SF-ZGa-ebAukJoAdUJFk5SPwnofV+Vg@mail.gmail.com/ Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Paul Menzel <pmenzel@molgen.mpg.de> Cc: Song Liu <songliubraving@fb.com> Cc: Rick Edgecombe <rick.p.edgecombe@intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> 
Since commit 559089e0a93d ("vmalloc: replace VM_NO_HUGE_VMAP with
VM_ALLOW_HUGE_VMAP"), the use of hugepage mappings for vmalloc is an
opt-in strategy, because it caused a number of problems that weren't
noticed until x86 enabled it too.

One of the issues was fixed by Nick Piggin in commit 3b8000ae185c
("mm/vmalloc: huge vmalloc backing pages should be split rather than
compound"), but I'm still worried about page protection issues, and
VM_FLUSH_RESET_PERMS in particular.

However, like the hash table allocation case (commit f2edd118d02d:
"page_alloc: use vmalloc_huge for large system hash"), the use of
kvmalloc() should be safe from any such games, since the returned
pointer might be a SLUB allocation, and as such no user should
reasonably be using it in any odd ways.

We also know that the allocations are fairly large, since it falls back
to the vmalloc case only when a kmalloc() fails.  So using a hugepage
mapping seems both safe and relevant.

This patch does show a weakness in the opt-in strategy: since the opt-in
flag is in the 'vm_flags', not the usual gfp_t allocation flags, very
few of the usual interfaces actually expose it.

That's not much of an issue in this case that already used one of the
fairly specialized low-level vmalloc interfaces for the allocation, but
for a lot of other vmalloc() users that might want to opt in, it's going
to be very inconvenient.

We'll either have to fix any compatibility problems, or expose it in the
gfp flags (__GFP_COMP would have made a lot of sense) to allow normal
vmalloc() users to use hugepage mappings.  That said, the cases that
really matter were probably already taken care of by the hash tabel
allocation.

Link: https://lore.kernel.org/all/20220415164413.2727220-1-song@kernel.org/
Link: https://lore.kernel.org/all/CAHk-=whao=iosX1s5Z4SF-ZGa-ebAukJoAdUJFk5SPwnofV+Vg@mail.gmail.com/
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Paul Menzel <pmenzel@molgen.mpg.de>
Cc: Song Liu <songliubraving@fb.com>
Cc: Rick Edgecombe <rick.p.edgecombe@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>