Commit graph

19296 commits

Author SHA1 Message Date
Linus Torvalds
0b1dcc2cf5 24 hotfixes. 8 marked cc:stable and 16 for post-6.0 issues.
There have been a lot of hotfixes this cycle, and this is quite a large
 batch given how far we are into the -rc cycle.  Presumably a reflection of
 the unusually large amount of MM material which went into 6.1-rc1.
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Merge tag 'mm-hotfixes-stable-2022-11-24' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull hotfixes from Andrew Morton:
 "24 MM and non-MM hotfixes. 8 marked cc:stable and 16 for post-6.0
  issues.

  There have been a lot of hotfixes this cycle, and this is quite a
  large batch given how far we are into the -rc cycle. Presumably a
  reflection of the unusually large amount of MM material which went
  into 6.1-rc1"

* tag 'mm-hotfixes-stable-2022-11-24' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (24 commits)
  test_kprobes: fix implicit declaration error of test_kprobes
  nilfs2: fix nilfs_sufile_mark_dirty() not set segment usage as dirty
  mm/cgroup/reclaim: fix dirty pages throttling on cgroup v1
  mm: fix unexpected changes to {failslab|fail_page_alloc}.attr
  swapfile: fix soft lockup in scan_swap_map_slots
  hugetlb: fix __prep_compound_gigantic_page page flag setting
  kfence: fix stack trace pruning
  proc/meminfo: fix spacing in SecPageTables
  mm: multi-gen LRU: retry folios written back while isolated
  mailmap: update email address for Satya Priya
  mm/migrate_device: return number of migrating pages in args->cpages
  kbuild: fix -Wimplicit-function-declaration in license_is_gpl_compatible
  MAINTAINERS: update Alex Hung's email address
  mailmap: update Alex Hung's email address
  mm: mmap: fix documentation for vma_mas_szero
  mm/damon/sysfs-schemes: skip stats update if the scheme directory is removed
  mm/memory: return vm_fault_t result from migrate_to_ram() callback
  mm: correctly charge compressed memory to its memcg
  ipc/shm: call underlying open/close vm_ops
  gcov: clang: fix the buffer overflow issue
  ...
2022-11-25 10:18:25 -08:00
Aneesh Kumar K.V
81a70c21d9 mm/cgroup/reclaim: fix dirty pages throttling on cgroup v1
balance_dirty_pages doesn't do the required dirty throttling on cgroupv1. 
See commit 9badce000e ("cgroup, writeback: don't enable cgroup writeback
on traditional hierarchies").  Instead, the kernel depends on writeback
throttling in shrink_folio_list to achieve the same goal.  With large
memory systems, the flusher may not be able to writeback quickly enough
such that we will start finding pages in the shrink_folio_list already in
writeback.  Hence for cgroupv1 let's do a reclaim throttle after waking up
the flusher.

The below test which used to fail on a 256GB system completes till the the
file system is full with this change.

root@lp2:/sys/fs/cgroup/memory# mkdir test
root@lp2:/sys/fs/cgroup/memory# cd test/
root@lp2:/sys/fs/cgroup/memory/test# echo 120M > memory.limit_in_bytes
root@lp2:/sys/fs/cgroup/memory/test# echo $$ > tasks
root@lp2:/sys/fs/cgroup/memory/test# dd if=/dev/zero of=/home/kvaneesh/test bs=1M
Killed

Link: https://lkml.kernel.org/r/20221118070603.84081-1-aneesh.kumar@linux.ibm.com
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Suggested-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: zefan li <lizefan.x@bytedance.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-11-22 18:50:45 -08:00
Qi Zheng
ea4452de2a mm: fix unexpected changes to {failslab|fail_page_alloc}.attr
When we specify __GFP_NOWARN, we only expect that no warnings will be
issued for current caller.  But in the __should_failslab() and
__should_fail_alloc_page(), the local GFP flags alter the global
{failslab|fail_page_alloc}.attr, which is persistent and shared by all
tasks.  This is not what we expected, let's fix it.

[akpm@linux-foundation.org: unexport should_fail_ex()]
Link: https://lkml.kernel.org/r/20221118100011.2634-1-zhengqi.arch@bytedance.com
Fixes: 3f913fc5f9 ("mm: fix missing handler for __GFP_NOWARN")
Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com>
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Akinobu Mita <akinobu.mita@gmail.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Cc: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-11-22 18:50:44 -08:00
Chen Wandun
de1ccfb648 swapfile: fix soft lockup in scan_swap_map_slots
A softlockup occurs in scan free swap slot under huge memory pressure. 
The test scenario is: 64 CPU cores, 64GB memory, and 28 zram devices, the
disksize of each zram device is 50MB.

LATENCY_LIMIT is used to prevent softlockups in scan_swap_map_slots(), but
the real loop number would more than LATENCY_LIMIT because of "goto checks
and goto scan" repeatly without decreasing latency limit.

In order to fix it, decrease latency_ration in advance.

There is also a suspicious place that will cause softlockups in
get_swap_pages().  In this function, the "goto start_over" may result in
continuous scanning of the swap partition.  If there is no cond_sched in
scan_swap_map_slots(), it would cause a softlockup (I am not sure about
this).

WARN: soft lockup - CPU#11 stuck for 11s! [kswapd0:466]
CPU: 11 PID: 466 Comm: kswapd@ Kdump: loaded Tainted: G
dump backtrace+0x0/0x1le4
show stack+0x20/@x2c
dump_stack+0xd8/0x140
watchdog print_info+0x48/0x54
watchdog_process_before_softlockup+0x98/0xa0
watchdog_timer_fn+0xlac/0x2d0
hrtimer_rum_queues+0xb0/0x130
hrtimer_interrupt+0x13c/0x3c0
arch_timer_handler_virt+0x3c/0x50
handLe_percpu_devid_irq+0x90/0x1f4
handle domain irq+0x84/0x100
gic_handle_irq+0x88/0x2b0
e11 ira+0xhB/Bx140
scan_swap_map_slots+0x678/0x890
get_swap_pages+0x29c/0x440
get_swap_page+0x120/0x2e0
add_to_swap+UX2U/0XyC
shrink_page_list+0x5d0/0x152c
shrink_inactive_list+0xl6c/Bx500
shrink_lruvec+0x270/0x304

WARN: soft lockup - CPU#32 stuck for 11s! [stress-ng:309915]
watchdog_timer_fn+0x1ac/0x2d0
__run_hrtimer+0x98/0x2a0
__hrtimer_run_queues+0xb0/0x130
hrtimer_interrupt+0x13c/0x3c0
arch_timer_handler_virt+0x3c/0x50
handle_percpu_devid_irq+0x90/0x1f4
__handle_domain_irq+0x84/0x100
gic_handle_irq+0x88/0x2b0
el1_irq+0xb8/0x140
get_swap_pages+0x1e8/0x440
get_swap_page+0x1c8/0x2e0
add_to_swap+0x20/0x9c
shrink_page_list+0x5d0/0x152c
reclaim_pages+0x160/0x310
madvise_cold_or_pageout_pte_range+0x7bc/0xe3c
walk_pmd_range.isra.0+0xac/0x22c
walk_pud_range+0xfc/0x1c0
walk_pgd_range+0x158/0x1b0
__walk_page_range+0x64/0x100
walk_page_range+0x104/0x150

Link: https://lkml.kernel.org/r/20221118133850.3360369-1-chenwandun@huawei.com
Fixes: 048c27fd72 ("[PATCH] swap: scan_swap_map latency breaks")
Signed-off-by: Chen Wandun <chenwandun@huawei.com>
Reviewed-by: "Huang, Ying" <ying.huang@intel.com>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Nanyong Sun <sunnanyong@huawei.com>
Cc: <xialonglong1@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-11-22 18:50:44 -08:00
Mike Kravetz
7fb0728a9b hugetlb: fix __prep_compound_gigantic_page page flag setting
Commit 2b21624fc2 ("hugetlb: freeze allocated pages before creating
hugetlb pages") changed the order page flags were cleared and set in the
head page.  It moved the __ClearPageReserved after __SetPageHead. 
However, there is a check to make sure __ClearPageReserved is never done
on a head page.  If CONFIG_DEBUG_VM_PGFLAGS is enabled, the following BUG
will be hit when creating a hugetlb gigantic page:

    page dumped because: VM_BUG_ON_PAGE(1 && PageCompound(page))
    ------------[ cut here ]------------
    kernel BUG at include/linux/page-flags.h:500!
    Call Trace will differ depending on whether hugetlb page is created
    at boot time or run time.

Make sure to __ClearPageReserved BEFORE __SetPageHead.

Link: https://lkml.kernel.org/r/20221118195249.178319-1-mike.kravetz@oracle.com
Fixes: 2b21624fc2 ("hugetlb: freeze allocated pages before creating hugetlb pages")
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Reported-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Acked-by: Muchun Song <songmuchun@bytedance.com>
Tested-by: Tarun Sahu <tsahu@linux.ibm.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Joao Martins <joao.m.martins@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Peter Xu <peterx@redhat.com>
Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-11-22 18:50:44 -08:00
Marco Elver
747c0f35f2 kfence: fix stack trace pruning
Commit b140513524 ("mm/sl[au]b: generalize kmalloc subsystem")
refactored large parts of the kmalloc subsystem, resulting in the stack
trace pruning logic done by KFENCE to no longer work.

While b140513524 attempted to fix the situation by including
'__kmem_cache_free' in the list of functions KFENCE should skip through,
this only works when the compiler actually optimized the tail call from
kfree() to __kmem_cache_free() into a jump (and thus kfree() _not_
appearing in the full stack trace to begin with).

In some configurations, the compiler no longer optimizes the tail call
into a jump, and __kmem_cache_free() appears in the stack trace.  This
means that the pruned stack trace shown by KFENCE would include kfree()
which is not intended - for example:

 | BUG: KFENCE: invalid free in kfree+0x7c/0x120
 |
 | Invalid free of 0xffff8883ed8fefe0 (in kfence-#126):
 |  kfree+0x7c/0x120
 |  test_double_free+0x116/0x1a9
 |  kunit_try_run_case+0x90/0xd0
 | [...]

Fix it by moving __kmem_cache_free() to the list of functions that may be
tail called by an allocator entry function, making the pruning logic work
in both the optimized and unoptimized tail call cases.

Link: https://lkml.kernel.org/r/20221118152216.3914899-1-elver@google.com
Fixes: b140513524 ("mm/sl[au]b: generalize kmalloc subsystem")
Signed-off-by: Marco Elver <elver@google.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Feng Tang <feng.tang@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-11-22 18:50:44 -08:00
Yu Zhao
359a5e1416 mm: multi-gen LRU: retry folios written back while isolated
The page reclaim isolates a batch of folios from the tail of one of the
LRU lists and works on those folios one by one.  For a suitable
swap-backed folio, if the swap device is async, it queues that folio for
writeback.  After the page reclaim finishes an entire batch, it puts back
the folios it queued for writeback to the head of the original LRU list.

In the meantime, the page writeback flushes the queued folios also by
batches.  Its batching logic is independent from that of the page reclaim.
For each of the folios it writes back, the page writeback calls
folio_rotate_reclaimable() which tries to rotate a folio to the tail.

folio_rotate_reclaimable() only works for a folio after the page reclaim
has put it back.  If an async swap device is fast enough, the page
writeback can finish with that folio while the page reclaim is still
working on the rest of the batch containing it.  In this case, that folio
will remain at the head and the page reclaim will not retry it before
reaching there.

This patch adds a retry to evict_folios().  After evict_folios() has
finished an entire batch and before it puts back folios it cannot free
immediately, it retries those that may have missed the rotation.

Before this patch, ~60% of folios swapped to an Intel Optane missed
folio_rotate_reclaimable().  After this patch, ~99% of missed folios were
reclaimed upon retry.

This problem affects relatively slow async swap devices like Samsung 980
Pro much less and does not affect sync swap devices like zram or zswap at
all.

Link: https://lkml.kernel.org/r/20221116013808.3995280-1-yuzhao@google.com
Fixes: ac35a49023 ("mm: multi-gen LRU: minimal implementation")
Signed-off-by: Yu Zhao <yuzhao@google.com>
Cc: "Yin, Fengwei" <fengwei.yin@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-11-22 18:50:43 -08:00
Alistair Popple
44af0b45d5 mm/migrate_device: return number of migrating pages in args->cpages
migrate_vma->cpages originally contained a count of the number of pages
migrating including non-present pages which can be populated directly on
the target.

Commit 241f688596 ("mm/migrate_device.c: refactor migrate_vma and
migrate_device_coherent_page()") inadvertantly changed this to contain
just the number of pages that were unmapped.  Usage of migrate_vma->cpages
isn't documented, but most drivers use it to see if all the requested
addresses can be migrated so restore the original behaviour.

Link: https://lkml.kernel.org/r/20221111005135.1344004-1-apopple@nvidia.com
Fixes: 241f688596 ("mm/migrate_device.c: refactor migrate_vma and migrate_deivce_coherent_page()")
Signed-off-by: Alistair Popple <apopple@nvidia.com>
Reported-by: Ralph Campbell <rcampbell@nvidia.com>
Reviewed-by: Ralph Campbell <rcampbell@nvidia.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Alex Sierra <alex.sierra@amd.com>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Felix Kuehling <Felix.Kuehling@amd.com>
Cc: Lyude Paul <lyude@redhat.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-11-22 18:50:43 -08:00
Ian Cowan
4a42344081 mm: mmap: fix documentation for vma_mas_szero
When the struct_mm input, mm, was changed to a struct ma_state, mas, the
documentation for the function was never updated.  This updates that
documentation reference.

Link: https://lkml.kernel.org/r/20221114003349.41235-1-ian@linux.cowan.aero
Signed-off-by: Ian Cowan <ian@linux.cowan.aero>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-11-22 18:50:42 -08:00
SeongJae Park
8468b48661 mm/damon/sysfs-schemes: skip stats update if the scheme directory is removed
A DAMON sysfs interface user can start DAMON with a scheme, remove the
sysfs directory for the scheme, and then ask update of the scheme's stats.
Because the schemes stats update logic isn't aware of the situation, it
results in an invalid memory access.  Fix the bug by checking if the
scheme sysfs directory exists.

Link: https://lkml.kernel.org/r/20221114175552.1951-1-sj@kernel.org
Fixes: 0ac32b8aff ("mm/damon/sysfs: support DAMOS stats")
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: <stable@vger.kernel.org>	[v5.18]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-11-22 18:50:42 -08:00
Alistair Popple
4a955bed88 mm/memory: return vm_fault_t result from migrate_to_ram() callback
The migrate_to_ram() callback should always succeed, but in rare cases can
fail usually returning VM_FAULT_SIGBUS.  Commit 16ce101db8
("mm/memory.c: fix race when faulting a device private page") incorrectly
stopped passing the return code up the stack.  Fix this by setting the ret
variable, restoring the previous behaviour on migrate_to_ram() failure.

Link: https://lkml.kernel.org/r/20221114115537.727371-1-apopple@nvidia.com
Fixes: 16ce101db8 ("mm/memory.c: fix race when faulting a device private page")
Signed-off-by: Alistair Popple <apopple@nvidia.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Alex Sierra <alex.sierra@amd.com>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Lyude Paul <lyude@redhat.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-11-22 18:50:42 -08:00
Li Liguang
cd08d80ecd mm: correctly charge compressed memory to its memcg
Kswapd will reclaim memory when memory pressure is high, the annonymous
memory will be compressed and stored in the zpool if zswap is enabled. 
The memcg_kmem_bypass() in get_obj_cgroup_from_page() will bypass the
kernel thread and cause the compressed memory not be charged to its memory
cgroup.

Remove the memcg_kmem_bypass() call and properly charge compressed memory
to its corresponding memory cgroup.

Link: https://lore.kernel.org/linux-mm/CALvZod4nnn8BHYqAM4xtcR0Ddo2-Wr8uKm9h_CHWUaXw7g_DCg@mail.gmail.com/
Link: https://lkml.kernel.org/r/20221114194828.100822-1-hannes@cmpxchg.org
Fixes: f4840ccfca ("zswap: memcg accounting")
Signed-off-by: Li Liguang <liliguang@baidu.com>
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Shakeel Butt <shakeelb@google.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: <stable@vger.kernel.org>	[5.19+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-11-22 18:50:42 -08:00
Gautam Menghani
045634ff1e mm/khugepaged: refactor mm_khugepaged_scan_file tracepoint to remove filename from function call
Refactor the mm_khugepaged_scan_file tracepoint to move filename
dereference to the tracepoint definition, to maintain consistency with
other tracepoints[1].

[1]:lore.kernel.org/lkml/20221024111621.3ba17e2c@gandalf.local.home/

Link: https://lkml.kernel.org/r/20221026044524.54793-1-gautammenghani201@gmail.com
Fixes: d41fd2016e ("mm/khugepaged: add tracepoint to hpage_collapse_scan_file()")
Signed-off-by: Gautam Menghani <gautammenghani201@gmail.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Reviewed-by: Zach O'Keefe <zokeefe@google.com>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-11-22 18:50:41 -08:00
Charan Teja Kalla
ed86b74874 mm/page_exit: fix kernel doc warning in page_ext_put()
Fix the below compiler warnings reported with 'make W=1 mm/'. 
mm/page_ext.c:178: warning: Function parameter or member 'page_ext' not
described in 'page_ext_put'.

[quic_pkondeti@quicinc.com: better patch title]
Link: https://lkml.kernel.org/r/1667884582-2465-1-git-send-email-quic_charante@quicinc.com
Fixes: b1d5488a25 ("mm: fix use-after free of page_ext after race with memory-offline")
Signed-off-by: Charan Teja Kalla <quic_charante@quicinc.com>
Reported-by: Vlastimil Babka <vbabka@suse.cz>
Tested-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Pavan Kondeti <quic_pkondeti@quicinc.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-11-22 18:50:41 -08:00
Yang Shi
e031ff96b3 mm: khugepaged: allow page allocation fallback to eligible nodes
Syzbot reported the below splat:

WARNING: CPU: 1 PID: 3646 at include/linux/gfp.h:221 __alloc_pages_node include/linux/gfp.h:221 [inline]
WARNING: CPU: 1 PID: 3646 at include/linux/gfp.h:221 hpage_collapse_alloc_page mm/khugepaged.c:807 [inline]
WARNING: CPU: 1 PID: 3646 at include/linux/gfp.h:221 alloc_charge_hpage+0x802/0xaa0 mm/khugepaged.c:963
Modules linked in:
CPU: 1 PID: 3646 Comm: syz-executor210 Not tainted 6.1.0-rc1-syzkaller-00454-ga70385240892 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/11/2022
RIP: 0010:__alloc_pages_node include/linux/gfp.h:221 [inline]
RIP: 0010:hpage_collapse_alloc_page mm/khugepaged.c:807 [inline]
RIP: 0010:alloc_charge_hpage+0x802/0xaa0 mm/khugepaged.c:963
Code: e5 01 4c 89 ee e8 6e f9 ae ff 4d 85 ed 0f 84 28 fc ff ff e8 70 fc ae ff 48 8d 6b ff 4c 8d 63 07 e9 16 fc ff ff e8 5e fc ae ff <0f> 0b e9 96 fa ff ff 41 bc 1a 00 00 00 e9 86 fd ff ff e8 47 fc ae
RSP: 0018:ffffc90003fdf7d8 EFLAGS: 00010293
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: ffff888077f457c0 RSI: ffffffff81cd8f42 RDI: 0000000000000001
RBP: ffff888079388c0c R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: dffffc0000000000 R14: 0000000000000000 R15: 0000000000000000
FS:  00007f6b48ccf700(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6b48a819f0 CR3: 00000000171e7000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 collapse_file+0x1ca/0x5780 mm/khugepaged.c:1715
 hpage_collapse_scan_file+0xd6c/0x17a0 mm/khugepaged.c:2156
 madvise_collapse+0x53a/0xb40 mm/khugepaged.c:2611
 madvise_vma_behavior+0xd0a/0x1cc0 mm/madvise.c:1066
 madvise_walk_vmas+0x1c7/0x2b0 mm/madvise.c:1240
 do_madvise.part.0+0x24a/0x340 mm/madvise.c:1419
 do_madvise mm/madvise.c:1432 [inline]
 __do_sys_madvise mm/madvise.c:1432 [inline]
 __se_sys_madvise mm/madvise.c:1430 [inline]
 __x64_sys_madvise+0x113/0x150 mm/madvise.c:1430
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f6b48a4eef9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 b1 15 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f6b48ccf318 EFLAGS: 00000246 ORIG_RAX: 000000000000001c
RAX: ffffffffffffffda RBX: 00007f6b48af0048 RCX: 00007f6b48a4eef9
RDX: 0000000000000019 RSI: 0000000000600003 RDI: 0000000020000000
RBP: 00007f6b48af0040 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f6b48aa53a4
R13: 00007f6b48bffcbf R14: 00007f6b48ccf400 R15: 0000000000022000
 </TASK>

The khugepaged code would pick up the node with the most hit as the preferred
node, and also tries to do some balance if several nodes have the same
hit record.  Basically it does conceptually:
    * If the target_node <= last_target_node, then iterate from
last_target_node + 1 to MAX_NUMNODES (1024 on default config)
    * If the max_value == node_load[nid], then target_node = nid

But there is a corner case, paritucularly for MADV_COLLAPSE, that the
non-existing node may be returned as preferred node.

Assuming the system has 2 nodes, the target_node is 0 and the
last_target_node is 1, if MADV_COLLAPSE path is hit, the max_value may
be 0, then it may return 2 for target_node, but it is actually not
existing (offline), so the warn is triggered.

The node balance was introduced by commit 9f1b868a13 ("mm: thp:
khugepaged: add policy for finding target node") to satisfy
"numactl --interleave=all".  But interleaving is a mere hint rather than
something that has hard requirements.

So use nodemask to record the nodes which have the same hit record, the
hugepage allocation could fallback to those nodes.  And remove
__GFP_THISNODE since it does disallow fallback.  And if the nodemask
just has one node set, it means there is one single node has the most
hit record, the nodemask approach actually behaves like __GFP_THISNODE.

Link: https://lkml.kernel.org/r/20221108184357.55614-2-shy828301@gmail.com
Fixes: 7d8faaf155 ("mm/madvise: introduce MADV_COLLAPSE sync hugepage collapse")
Signed-off-by: Yang Shi <shy828301@gmail.com>
Suggested-by: Zach O'Keefe <zokeefe@google.com>
Suggested-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Zach O'Keefe <zokeefe@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reported-by: <syzbot+0044b22d177870ee974f@syzkaller.appspotmail.com>

Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-11-22 18:50:41 -08:00
Johannes Weiner
f53af4285d mm: vmscan: fix extreme overreclaim and swap floods
During proactive reclaim, we sometimes observe severe overreclaim, with
several thousand times more pages reclaimed than requested.

This trace was obtained from shrink_lruvec() during such an instance:

    prio:0 anon_cost:1141521 file_cost:7767
    nr_reclaimed:4387406 nr_to_reclaim:1047 (or_factor:4190)
    nr=[7161123 345 578 1111]

While he reclaimer requested 4M, vmscan reclaimed close to 16G, most of it
by swapping.  These requests take over a minute, during which the write()
to memory.reclaim is unkillably stuck inside the kernel.

Digging into the source, this is caused by the proportional reclaim
bailout logic.  This code tries to resolve a fundamental conflict: to
reclaim roughly what was requested, while also aging all LRUs fairly and
in accordance to their size, swappiness, refault rates etc.  The way it
attempts fairness is that once the reclaim goal has been reached, it stops
scanning the LRUs with the smaller remaining scan targets, and adjusts the
remainder of the bigger LRUs according to how much of the smaller LRUs was
scanned.  It then finishes scanning that remainder regardless of the
reclaim goal.

This works fine if priority levels are low and the LRU lists are
comparable in size.  However, in this instance, the cgroup that is
targeted by proactive reclaim has almost no files left - they've already
been squeezed out by proactive reclaim earlier - and the remaining anon
pages are hot.  Anon rotations cause the priority level to drop to 0,
which results in reclaim targeting all of anon (a lot) and all of file
(almost nothing).  By the time reclaim decides to bail, it has scanned
most or all of the file target, and therefor must also scan most or all of
the enormous anon target.  This target is thousands of times larger than
the reclaim goal, thus causing the overreclaim.

The bailout code hasn't changed in years, why is this failing now?  The
most likely explanations are two other recent changes in anon reclaim:

1. Before the series starting with commit 5df741963d ("mm: fix LRU
   balancing effect of new transparent huge pages"), the VM was
   overall relatively reluctant to swap at all, even if swap was
   configured. This means the LRU balancing code didn't come into play
   as often as it does now, and mostly in high pressure situations
   where pronounced swap activity wouldn't be as surprising.

2. For historic reasons, shrink_lruvec() loops on the scan targets of
   all LRU lists except the active anon one, meaning it would bail if
   the only remaining pages to scan were active anon - even if there
   were a lot of them.

   Before the series starting with commit ccc5dc6734 ("mm/vmscan:
   make active/inactive ratio as 1:1 for anon lru"), most anon pages
   would live on the active LRU; the inactive one would contain only a
   handful of preselected reclaim candidates. After the series, anon
   gets aged similarly to file, and the inactive list is the default
   for new anon pages as well, making it often the much bigger list.

   As a result, the VM is now more likely to actually finish large
   anon targets than before.

Change the code such that only one SWAP_CLUSTER_MAX-sized nudge toward the
larger LRU lists is made before bailing out on a met reclaim goal.

This fixes the extreme overreclaim problem.

Fairness is more subtle and harder to evaluate.  No obvious misbehavior
was observed on the test workload, in any case.  Conceptually, fairness
should primarily be a cumulative effect from regular, lower priority
scans.  Once the VM is in trouble and needs to escalate scan targets to
make forward progress, fairness needs to take a backseat.  This is also
acknowledged by the myriad exceptions in get_scan_count().  This patch
makes fairness decrease gradually, as it keeps fairness work static over
increasing priority levels with growing scan targets.  This should make
more sense - although we may have to re-visit the exact values.

Link: https://lkml.kernel.org/r/20220802162811.39216-1-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Rik van Riel <riel@surriel.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Hugh Dickins <hughd@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-11-22 18:50:41 -08:00
Linus Torvalds
847ccab8fd Networking fixes for 6.1-rc6, including fixes from bpf
Current release - regressions:
 
   - tls: fix memory leak in tls_enc_skb() and tls_sw_fallback_init()
 
 Previous releases - regressions:
 
   - bridge: fix memory leaks when changing VLAN protocol
 
   - dsa: make dsa_master_ioctl() see through port_hwtstamp_get() shims
 
   - dsa: don't leak tagger-owned storage on switch driver unbind
 
   - eth: mlxsw: avoid warnings when not offloaded FDB entry with IPv6 is removed
 
   - eth: stmmac: ensure tx function is not running in stmmac_xdp_release()
 
   - eth: hns3: fix return value check bug of rx copybreak
 
 Previous releases - always broken:
 
   - kcm: close race conditions on sk_receive_queue
 
   - bpf: fix alignment problem in bpf_prog_test_run_skb()
 
   - bpf: fix writing offset in case of fault in strncpy_from_kernel_nofault
 
   - eth: macvlan: use built-in RCU list checking
 
   - eth: marvell: add sleep time after enabling the loopback bit
 
   - eth: octeon_ep: fix potential memory leak in octep_device_setup()
 
 Misc:
 
   - tcp: configurable source port perturb table size
 
   - bpf: Convert BPF_DISPATCHER to use static_call() (not ftrace)
 
 Signed-off-by: Paolo Abeni <pabeni@redhat.com>
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Merge tag 'net-6.1-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

Pull networking fixes from Paolo Abeni:
 "Including fixes from bpf.

  Current release - regressions:

   - tls: fix memory leak in tls_enc_skb() and tls_sw_fallback_init()

  Previous releases - regressions:

   - bridge: fix memory leaks when changing VLAN protocol

   - dsa: make dsa_master_ioctl() see through port_hwtstamp_get() shims

   - dsa: don't leak tagger-owned storage on switch driver unbind

   - eth: mlxsw: avoid warnings when not offloaded FDB entry with IPv6
     is removed

   - eth: stmmac: ensure tx function is not running in
     stmmac_xdp_release()

   - eth: hns3: fix return value check bug of rx copybreak

  Previous releases - always broken:

   - kcm: close race conditions on sk_receive_queue

   - bpf: fix alignment problem in bpf_prog_test_run_skb()

   - bpf: fix writing offset in case of fault in
     strncpy_from_kernel_nofault

   - eth: macvlan: use built-in RCU list checking

   - eth: marvell: add sleep time after enabling the loopback bit

   - eth: octeon_ep: fix potential memory leak in octep_device_setup()

  Misc:

   - tcp: configurable source port perturb table size

   - bpf: Convert BPF_DISPATCHER to use static_call() (not ftrace)"

* tag 'net-6.1-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (51 commits)
  net: use struct_group to copy ip/ipv6 header addresses
  net: usb: smsc95xx: fix external PHY reset
  net: usb: qmi_wwan: add Telit 0x103a composition
  netdevsim: Fix memory leak of nsim_dev->fa_cookie
  tcp: configurable source port perturb table size
  l2tp: Serialize access to sk_user_data with sk_callback_lock
  net: thunderbolt: Fix error handling in tbnet_init()
  net: microchip: sparx5: Fix potential null-ptr-deref in sparx_stats_init() and sparx5_start()
  net: lan966x: Fix potential null-ptr-deref in lan966x_stats_init()
  net: dsa: don't leak tagger-owned storage on switch driver unbind
  net/x25: Fix skb leak in x25_lapb_receive_frame()
  net: ag71xx: call phylink_disconnect_phy if ag71xx_hw_enable() fail in ag71xx_open()
  bridge: switchdev: Fix memory leaks when changing VLAN protocol
  net: hns3: fix setting incorrect phy link ksettings for firmware in resetting process
  net: hns3: fix return value check bug of rx copybreak
  net: hns3: fix incorrect hw rss hash type of rx packet
  net: phy: marvell: add sleep time after enabling the loopback bit
  net: ena: Fix error handling in ena_init()
  kcm: close race conditions on sk_receive_queue
  net: ionic: Fix error handling in ionic_init_module()
  ...
2022-11-17 08:58:36 -08:00
Jakub Kicinski
c1754bf019 Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Andrii Nakryiko says:

====================
bpf 2022-11-11

We've added 11 non-merge commits during the last 8 day(s) which contain
a total of 11 files changed, 83 insertions(+), 74 deletions(-).

The main changes are:

1) Fix strncpy_from_kernel_nofault() to prevent out-of-bounds writes,
   from Alban Crequy.

2) Fix for bpf_prog_test_run_skb() to prevent wrong alignment,
   from Baisong Zhong.

3) Switch BPF_DISPATCHER to static_call() instead of ftrace infra, with
   a small build fix on top, from Peter Zijlstra and Nathan Chancellor.

4) Fix memory leak in BPF verifier in some error cases, from Wang Yufen.

5) 32-bit compilation error fixes for BPF selftests, from Pu Lehui and
   Yang Jihong.

6) Ensure even distribution of per-CPU free list elements, from Xu Kuohai.

7) Fix copy_map_value() to track special zeroed out areas properly,
   from Xu Kuohai.

* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
  bpf: Fix offset calculation error in __copy_map_value and zero_map_value
  bpf: Initialize same number of free nodes for each pcpu_freelist
  selftests: bpf: Add a test when bpf_probe_read_kernel_str() returns EFAULT
  maccess: Fix writing offset in case of fault in strncpy_from_kernel_nofault()
  selftests/bpf: Fix test_progs compilation failure in 32-bit arch
  selftests/bpf: Fix casting error when cross-compiling test_verifier for 32-bit platforms
  bpf: Fix memory leaks in __check_func_call
  bpf: Add explicit cast to 'void *' for __BPF_DISPATCHER_UPDATE()
  bpf: Convert BPF_DISPATCHER to use static_call() (not ftrace)
  bpf: Revert ("Fix dispatcher patchable function entry to 5 bytes nop")
  bpf, test_run: Fix alignment problem in bpf_prog_test_run_skb()
====================

Link: https://lore.kernel.org/r/20221111231624.938829-1-andrii@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-11-11 18:27:40 -08:00
Linus Torvalds
d7c2b1f64e 22 hotfixes. 8 are cc:stable and the remainder address issues which were
introduced post-6.0 or which aren't considered serious enough to justify a
 -stable backport.
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Merge tag 'mm-hotfixes-stable-2022-11-11' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull misc hotfixes from Andrew Morton:
 "22 hotfixes.

  Eight are cc:stable and the remainder address issues which were
  introduced post-6.0 or which aren't considered serious enough to
  justify a -stable backport"

* tag 'mm-hotfixes-stable-2022-11-11' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (22 commits)
  docs: kmsan: fix formatting of "Example report"
  mm/damon/dbgfs: check if rm_contexts input is for a real context
  maple_tree: don't set a new maximum on the node when not reusing nodes
  maple_tree: fix depth tracking in maple_state
  arch/x86/mm/hugetlbpage.c: pud_huge() returns 0 when using 2-level paging
  fs: fix leaked psi pressure state
  nilfs2: fix use-after-free bug of ns_writer on remount
  x86/traps: avoid KMSAN bugs originating from handle_bug()
  kmsan: make sure PREEMPT_RT is off
  Kconfig.debug: ensure early check for KMSAN in CONFIG_KMSAN_WARN
  x86/uaccess: instrument copy_from_user_nmi()
  kmsan: core: kmsan_in_runtime() should return true in NMI context
  mm: hugetlb_vmemmap: include missing linux/moduleparam.h
  mm/shmem: use page_mapping() to detect page cache for uffd continue
  mm/memremap.c: map FS_DAX device memory as decrypted
  Partly revert "mm/thp: carry over dirty bit when thp splits on pmd"
  nilfs2: fix deadlock in nilfs_count_free_blocks()
  mm/mmap: fix memory leak in mmap_region()
  hugetlbfs: don't delete error page from pagecache
  maple_tree: reorganize testing to restore module testing
  ...
2022-11-11 17:18:42 -08:00
Alban Crequy
8678ea0685 maccess: Fix writing offset in case of fault in strncpy_from_kernel_nofault()
If a page fault occurs while copying the first byte, this function resets one
byte before dst.
As a consequence, an address could be modified and leaded to kernel crashes if
case the modified address was accessed later.

Fixes: b58294ead1 ("maccess: allow architectures to provide kernel probing directly")
Signed-off-by: Alban Crequy <albancrequy@linux.microsoft.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Tested-by: Francis Laniel <flaniel@linux.microsoft.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: <stable@vger.kernel.org> [5.8]
Link: https://lore.kernel.org/bpf/20221110085614.111213-2-albancrequy@linux.microsoft.com
2022-11-11 11:44:46 -08:00
Linus Torvalds
f67dd6ce07 slab fixes for 6.1-rc4
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Merge tag 'slab-for-6.1-rc4-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab

Pull slab fixes from Vlastimil Babka:
 "Most are small fixups as described below.

  The !CONFIG_TRACING fix is a bit bigger and would normally be done in
  the next merge window as part of upcoming hardening changes. But we
  realized it can make the kmalloc waste tracking introduced in this
  window inaccurate, so decided to go with it now.

  Summary:

   - Remove !CONFIG_TRACING kmalloc() wrappers intended to save a
     function call, due to incompatilibity with recently introduced
     wasted space tracking and planned hardening changes.

   - A tracing parameter regression fix, by Kees Cook.

   - Two kernel-doc warning fixups, by Lukas Bulwahn and myself

* tag 'slab-for-6.1-rc4-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab:
  mm, slab: remove duplicate kernel-doc comment for ksize()
  mm/slab_common: Restore passing "caller" for tracing
  mm/slab: remove !CONFIG_TRACING variants of kmalloc_[node_]trace()
  mm/slab_common: repair kernel-doc for __ksize()
2022-11-09 13:07:50 -08:00
SeongJae Park
1de09a7281 mm/damon/dbgfs: check if rm_contexts input is for a real context
A user could write a name of a file under 'damon/' debugfs directory,
which is not a user-created context, to 'rm_contexts' file.  In the case,
'dbgfs_rm_context()' just assumes it's the valid DAMON context directory
only if a file of the name exist.  As a result, invalid memory access
could happen as below.  Fix the bug by checking if the given input is for
a directory.  This check can filter out non-context inputs because
directories under 'damon/' debugfs directory can be created via only
'mk_contexts' file.

This bug has found by syzbot[1].

[1] https://lore.kernel.org/damon/000000000000ede3ac05ec4abf8e@google.com/

Link: https://lkml.kernel.org/r/20221107165001.5717-2-sj@kernel.org
Fixes: 75c1c2b53c ("mm/damon/dbgfs: support multiple contexts")
Signed-off-by: SeongJae Park <sj@kernel.org>
Reported-by: syzbot+6087eafb76a94c4ac9eb@syzkaller.appspotmail.com
Cc: <stable@vger.kernel.org>	[5.15.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-11-08 15:57:25 -08:00
Alexander Potapenko
cbadaf71f7 kmsan: core: kmsan_in_runtime() should return true in NMI context
Without that, every call to __msan_poison_alloca() in NMI may end up
allocating memory, which is NMI-unsafe.

Link: https://lkml.kernel.org/r/20221102110611.1085175-1-glider@google.com
Link: https://lore.kernel.org/lkml/20221025221755.3810809-1-glider@google.com/
Signed-off-by: Alexander Potapenko <glider@google.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Marco Elver <elver@google.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-11-08 15:57:24 -08:00
Vasily Gorbik
db5e8d8431 mm: hugetlb_vmemmap: include missing linux/moduleparam.h
The kernel test robot reported build failures with a 'randconfig' on s390:
>> mm/hugetlb_vmemmap.c:421:11: error: a function declaration without a
prototype is deprecated in all versions of C [-Werror,-Wstrict-prototypes]
   core_param(hugetlb_free_vmemmap, vmemmap_optimize_enabled, bool, 0);
             ^

Link: https://lore.kernel.org/linux-mm/202210300751.rG3UDsuc-lkp@intel.com/
Link: https://lkml.kernel.org/r/patch.git-296b83ca939b.your-ad-here.call-01667411912-ext-5073@work.hours
Fixes: 30152245c6 ("mm: hugetlb_vmemmap: replace early_param() with core_param()")
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Reported-by: kernel test robot <lkp@intel.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-11-08 15:57:23 -08:00
Peter Xu
93b0d91787 mm/shmem: use page_mapping() to detect page cache for uffd continue
mfill_atomic_install_pte() checks page->mapping to detect whether one page
is used in the page cache.  However as pointed out by Matthew, the page
can logically be a tail page rather than always the head in the case of
uffd minor mode with UFFDIO_CONTINUE.  It means we could wrongly install
one pte with shmem thp tail page assuming it's an anonymous page.

It's not that clear even for anonymous page, since normally anonymous
pages also have page->mapping being setup with the anon vma.  It's safe
here only because the only such caller to mfill_atomic_install_pte() is
always passing in a newly allocated page (mcopy_atomic_pte()), whose
page->mapping is not yet setup.  However that's not extremely obvious
either.

For either of above, use page_mapping() instead.

Link: https://lkml.kernel.org/r/Y2K+y7wnhC4vbnP2@x1n
Fixes: 153132571f ("userfaultfd/shmem: support UFFDIO_CONTINUE for shmem")
Signed-off-by: Peter Xu <peterx@redhat.com>
Reported-by: Matthew Wilcox <willy@infradead.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-11-08 15:57:23 -08:00
Pankaj Gupta
867400af90 mm/memremap.c: map FS_DAX device memory as decrypted
virtio_pmem use devm_memremap_pages() to map the device memory.  By
default this memory is mapped as encrypted with SEV.  Guest reboot changes
the current encryption key and guest no longer properly decrypts the FSDAX
device meta data.

Mark the corresponding device memory region for FSDAX devices (mapped with
memremap_pages) as decrypted to retain the persistent memory property.

Link: https://lkml.kernel.org/r/20221102160728.3184016-1-pankaj.gupta@amd.com
Fixes: b7b3c01b19 ("mm/memremap_pages: support multiple ranges per invocation")
Signed-off-by: Pankaj Gupta <pankaj.gupta@amd.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-11-08 15:57:23 -08:00
Peter Xu
624a2c94f5 Partly revert "mm/thp: carry over dirty bit when thp splits on pmd"
Anatoly Pugachev reported sparc64 breakage on the patch:

https://lore.kernel.org/r/20221021160603.GA23307@u164.east.ru

The sparc64 impl of pte_mkdirty() is definitely slightly special in that
it leverages a code patching mechanism for sun4u/sun4v on relevant pgtable
entry operations.

Before having a clue of why the sparc64 is special and caused the patch to
SIGSEGV the processes, revert the patch for now.  The swap path of dirty
bit inheritage is kept because that's using the swap shared code so we
assume it'll not be affected.

Link: https://lkml.kernel.org/r/Y1Wbi4yyVvDtg4zN@x1n
Fixes: 0ccf7f168e ("mm/thp: carry over dirty bit when thp splits on pmd")
Signed-off-by: Peter Xu <peterx@redhat.com>
Reported-by: Anatoly Pugachev <matorola@gmail.com> 
Tested-by: Anatoly Pugachev <matorola@gmail.com> 
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Andi Kleen <andi.kleen@intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: "Kirill A . Shutemov" <kirill@shutemov.name>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Nadav Amit <nadav.amit@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-11-08 15:57:23 -08:00
Li Zetao
cc674ab3c0 mm/mmap: fix memory leak in mmap_region()
There is a memory leak reported by kmemleak:

  unreferenced object 0xffff88817231ce40 (size 224):
    comm "mount.cifs", pid 19308, jiffies 4295917571 (age 405.880s)
    hex dump (first 32 bytes):
      00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
      60 c0 b2 00 81 88 ff ff 98 83 01 42 81 88 ff ff  `..........B....
    backtrace:
      [<ffffffff81936171>] __alloc_file+0x21/0x250
      [<ffffffff81937051>] alloc_empty_file+0x41/0xf0
      [<ffffffff81937159>] alloc_file+0x59/0x710
      [<ffffffff81937964>] alloc_file_pseudo+0x154/0x210
      [<ffffffff81741dbf>] __shmem_file_setup+0xff/0x2a0
      [<ffffffff817502cd>] shmem_zero_setup+0x8d/0x160
      [<ffffffff817cc1d5>] mmap_region+0x1075/0x19d0
      [<ffffffff817cd257>] do_mmap+0x727/0x1110
      [<ffffffff817518b2>] vm_mmap_pgoff+0x112/0x1e0
      [<ffffffff83adf955>] do_syscall_64+0x35/0x80
      [<ffffffff83c0006a>] entry_SYSCALL_64_after_hwframe+0x46/0xb0

The root cause was traced to an error handing path in mmap_region() when
arch_validate_flags() or mas_preallocate() fails.  In the shared anonymous
mapping sence, vma will be setuped and mapped with a new shared anonymous
file via shmem_zero_setup().  So in this case, the file resource needs to
be released.

Fix it by calling fput(vma->vm_file) and unmap_region() when
arch_validate_flags() or mas_preallocate() returns an error in the shared
anonymous mapping sence.

Link: https://lkml.kernel.org/r/20221028073717.1179380-1-lizetao1@huawei.com
Fixes: d4af56c5c7 ("mm: start tracking VMAs with maple tree")
Fixes: c462ac288f ("mm: Introduce arch_validate_flags()")
Signed-off-by: Li Zetao <lizetao1@huawei.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-11-08 15:57:23 -08:00
James Houghton
8625147caf hugetlbfs: don't delete error page from pagecache
This change is very similar to the change that was made for shmem [1], and
it solves the same problem but for HugeTLBFS instead.

Currently, when poison is found in a HugeTLB page, the page is removed
from the page cache.  That means that attempting to map or read that
hugepage in the future will result in a new hugepage being allocated
instead of notifying the user that the page was poisoned.  As [1] states,
this is effectively memory corruption.

The fix is to leave the page in the page cache.  If the user attempts to
use a poisoned HugeTLB page with a syscall, the syscall will fail with
EIO, the same error code that shmem uses.  For attempts to map the page,
the thread will get a BUS_MCEERR_AR SIGBUS.

[1]: commit a760542666 ("mm: shmem: don't truncate page if memory failure happens")

Link: https://lkml.kernel.org/r/20221018200125.848471-1-jthoughton@google.com
Signed-off-by: James Houghton <jthoughton@google.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Tested-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: James Houghton <jthoughton@google.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-11-08 15:57:22 -08:00
Vlastimil Babka
c18c20f162 mm, slab: remove duplicate kernel-doc comment for ksize()
Akira reports:

> "make htmldocs" reports duplicate C declaration of ksize() as follows:

> /linux/Documentation/core-api/mm-api:43: ./mm/slab_common.c:1428: WARNING: Duplicate C declaration, also defined at core-api/mm-api:212.
> Declaration is '.. c:function:: size_t ksize (const void *objp)'.

> This is due to the kernel-doc comment for ksize() declaration added in
> include/linux/slab.h by commit 05a940656e ("slab: Introduce
> kmalloc_size_roundup()").

There is an older kernel-doc comment for ksize() definition in
mm/slab_common.c, which is not only duplicated, but also contradicts the
new one - the additional storage discovered by ksize() should not be
used by callers anymore. Delete the old kernel-doc.

Reported-by: Akira Yokosawa <akiyks@gmail.com>
Link: https://lore.kernel.org/all/d33440f6-40cf-9747-3340-e54ffaf7afb8@gmail.com/
Fixes: 05a940656e ("slab: Introduce kmalloc_size_roundup()")
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2022-11-07 17:11:27 +01:00
Kees Cook
328687151b mm/slab_common: Restore passing "caller" for tracing
The "caller" argument was accidentally being ignored in a few places
that were recently refactored. Restore these "caller" arguments, instead
of _RET_IP_.

Fixes: 11e9734bcb ("mm/slab_common: unify NUMA and UMA version of tracepoints")
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: linux-mm@kvack.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2022-11-06 21:20:46 +01:00
Vlastimil Babka
eb4940d4ad mm/slab: remove !CONFIG_TRACING variants of kmalloc_[node_]trace()
For !CONFIG_TRACING kernels, the kmalloc() implementation tries (in cases where
the allocation size is build-time constant) to save a function call, by
inlining kmalloc_trace() to a kmem_cache_alloc() call.

However since commit 6edf2576a6 ("mm/slub: enable debugging memory wasting of
kmalloc") this path now fails to pass the original request size to be
eventually recorded (for kmalloc caches with debugging enabled).

We could adjust the code to call __kmem_cache_alloc_node() as the
CONFIG_TRACING variant, but that would as a result inline a call with 5
parameters, bloating the kmalloc() call sites. The cost of extra function
call (to kmalloc_trace()) seems like a lesser evil.

It also appears that the !CONFIG_TRACING variant is incompatible with upcoming
hardening efforts [1] so it's easier if we just remove it now. Kernels with no
tracing are rare these days and the benefit is dubious anyway.

[1] https://lore.kernel.org/linux-mm/20221101222520.never.109-kees@kernel.org/T/#m20ecf14390e406247bde0ea9cce368f469c539ed

Link: https://lore.kernel.org/all/097d8fba-bd10-a312-24a3-a4068c4f424c@suse.cz/
Suggested-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2022-11-04 14:57:21 +01:00
Lukas Bulwahn
a207620123 mm/slab_common: repair kernel-doc for __ksize()
Commit 445d41d7a7 ("Merge branch 'slab/for-6.1/kmalloc_size_roundup' into
slab/for-next") resolved a conflict of two concurrent changes to __ksize().

However, it did not adjust the kernel-doc comment of __ksize(), while the
name of the argument to __ksize() was renamed.

Hence, ./scripts/ kernel-doc -none mm/slab_common.c warns about it.

Adjust the kernel-doc comment for __ksize() for make W=1 happiness.

Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Acked-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2022-11-03 18:09:45 +01:00
Liam Howlett
1db43d3f37 mmap: fix remap_file_pages() regression
When using the VMA iterator, the final execution will set the variable
'next' to NULL which causes the function to fail out.  Restore the break
in the loop to exit the VMA iterator early without clearing NULL fixes the
issue.

Link: https://lore.kernel.org/lkml/29344.1666681759@jrobl/
Link: https://lkml.kernel.org/r/20221025161222.2634030-1-Liam.Howlett@oracle.com
Fixes: 763ecb0350 (mm: remove the vma linked list)
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Reported-by: "J. R. Okajima" <hooanon05g@gmail.com>
Tested-by: "J. R. Okajima" <hooanon05g@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-28 13:37:23 -07:00
Ira Weiny
5dc21f0c0b mm/shmem: ensure proper fallback if page faults
The kernel test robot flagged a recursive lock as a result of a conversion
from kmap_atomic() to kmap_local_folio()[Link]

The cause was due to the code depending on the kmap_atomic() side effect
of disabling page faults.  In that case the code expects the fault to fail
and take the fallback case.

git archaeology implied that the recursion may not be an actual bug.[1]
However, depending on the implementation of the mmap_lock and the
condition of the call there may still be a deadlock.[2] So this is not
purely a lockdep issue.  Considering a single threaded call stack there
are 3 options.

	1) Different mm's are in play (no issue)
	2) Readlock implementation is recursive and same mm is in play
	   (no issue)
	3) Readlock implementation is _not_ recursive (issue)

The mmap_lock is recursive so with a single thread there is no issue.

However, Matthew pointed out a deadlock scenario when you consider
additional process' and threads thusly.

"The readlock implementation is only recursive if nobody else has taken a
write lock.  If you have a multithreaded process, one of the other threads
can call mmap() and that will prevent recursion (due to fairness).  Even
if it's a different process that you're trying to acquire the mmap read
lock on, you can still get into a deadly embrace.  eg:

process A thread 1 takes read lock on own mmap_lock
process A thread 2 calls mmap, blocks taking write lock
process B thread 1 takes page fault, read lock on own mmap lock
process B thread 2 calls mmap, blocks taking write lock
process A thread 1 blocks taking read lock on process B
process B thread 1 blocks taking read lock on process A

Now all four threads are blocked waiting for each other."

Regardless using pagefault_disable() ensures that no matter what locking
implementation is used a deadlock will not occur.  Add an explicit
pagefault_disable() and a big comment to explain this for future souls
looking at this code.

[1] https://lore.kernel.org/all/Y1MymJ%2FINb45AdaY@iweiny-desk3/
[2] https://lore.kernel.org/lkml/Y1bXBtGTCym77%2FoD@casper.infradead.org/

Link: https://lkml.kernel.org/r/20221025220108.2366043-1-ira.weiny@intel.com
Link: https://lore.kernel.org/r/202210211215.9dc6efb5-yujie.liu@intel.com
Fixes: 7a7256d5f5 ("shmem: convert shmem_mfill_atomic_pte() to use a folio")
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Reported-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reported-by: kernel test robot <yujie.liu@intel.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Peter Xu <peterx@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-28 13:37:23 -07:00
Ira Weiny
5521de7ddd mm/userfaultfd: replace kmap/kmap_atomic() with kmap_local_page()
kmap() and kmap_atomic() are being deprecated in favor of
kmap_local_page() which is appropriate for any thread local context.[1]

A recent locking bug report with userfaultfd showed that the conversion of
the kmap_atomic()'s in those code flows requires care with regard to the
prevention of deadlock.[2]

git archaeology implied that the recursion may not be an actual bug.[3]
However, depending on the implementation of the mmap_lock and the
condition of the call there may still be a deadlock.[4] So this is not
purely a lockdep issue.  Considering a single threaded call stack there
are 3 options.

	1) Different mm's are in play (no issue)
	2) Readlock implementation is recursive and same mm is in play
	   (no issue)
	3) Readlock implementation is _not_ recursive (issue)

The mmap_lock is recursive so with a single thread there is no issue.

However, Matthew pointed out a deadlock scenario when you consider
additional process' and threads thusly.

"The readlock implementation is only recursive if nobody else has taken a
write lock.  If you have a multithreaded process, one of the other threads
can call mmap() and that will prevent recursion (due to fairness).  Even
if it's a different process that you're trying to acquire the mmap read
lock on, you can still get into a deadly embrace.  eg:

process A thread 1 takes read lock on own mmap_lock
process A thread 2 calls mmap, blocks taking write lock
process B thread 1 takes page fault, read lock on own mmap lock
process B thread 2 calls mmap, blocks taking write lock
process A thread 1 blocks taking read lock on process B
process B thread 1 blocks taking read lock on process A

Now all four threads are blocked waiting for each other."

Regardless using pagefault_disable() ensures that no matter what locking
implementation is used a deadlock will not occur.

Complete kmap conversion in userfaultfd by replacing the kmap() and
kmap_atomic() calls with kmap_local_page().  When replacing the
kmap_atomic() call ensure page faults continue to be disabled to support
the correct fall back behavior and add a comment to inform future souls of
the requirement.

[1] https://lore.kernel.org/all/20220813220034.806698-1-ira.weiny@intel.com/
[2] https://lore.kernel.org/all/Y1Mh2S7fUGQ%2FiKFR@iweiny-desk3/
[3] https://lore.kernel.org/all/Y1MymJ%2FINb45AdaY@iweiny-desk3/
[4] https://lore.kernel.org/lkml/Y1bXBtGTCym77%2FoD@casper.infradead.org/

[ira.weiny@intel.com: v2]
  Link: https://lkml.kernel.org/r/20221025220136.2366143-1-ira.weiny@intel.com
Link: https://lkml.kernel.org/r/20221024043452.1491677-1-ira.weiny@intel.com
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-28 13:37:23 -07:00
Alexander Potapenko
78a498c3a2 x86: fortify: kmsan: fix KMSAN fortify builds
Ensure that KMSAN builds replace memset/memcpy/memmove calls with the
respective __msan_XXX functions, and that none of the macros are redefined
twice.  This should allow building kernel with both CONFIG_KMSAN and
CONFIG_FORTIFY_SOURCE.

Link: https://lkml.kernel.org/r/20221024212144.2852069-5-glider@google.com
Link: https://github.com/google/kmsan/issues/89
Signed-off-by: Alexander Potapenko <glider@google.com>
Reported-by: Tamas K Lengyel <tamas.lengyel@zentific.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-28 13:37:23 -07:00
Alexander Potapenko
f59a3ee691 mm: kmsan: export kmsan_copy_page_meta()
Certain modules call copy_user_highpage(), which calls
kmsan_copy_page_meta() under KMSAN, so we need to export the latter.

Link: https://lkml.kernel.org/r/20221024212144.2852069-1-glider@google.com
Link: https://github.com/google/kmsan/issues/89
Fixes: b073d7f8ae ("mm: kmsan: maintain KMSAN metadata for page operations")
Signed-off-by: Alexander Potapenko <glider@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-28 13:37:22 -07:00
Baolin Wang
03e5f82ea6 mm: migrate: fix return value if all subpages of THPs are migrated successfully
During THP migration, if THPs are not migrated but they are split and all
subpages are migrated successfully, migrate_pages() will still return the
number of THP pages that were not migrated.  This will confuse the callers
of migrate_pages().  For example, the longterm pinning will failed though
all pages are migrated successfully.

Thus we should return 0 to indicate that all pages are migrated in this
case

Link: https://lkml.kernel.org/r/de386aa864be9158d2f3b344091419ea7c38b2f7.1666599848.git.baolin.wang@linux.alibaba.com
Fixes: b5bade978e ("mm: migrate: fix the return value of migrate_pages()")
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Reviewed-by: Alistair Popple <apopple@nvidia.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-28 13:37:22 -07:00
Hugh Dickins
5aae9265ee mm: prep_compound_tail() clear page->private
Although page allocation always clears page->private in the first page or
head page of an allocation, it has never made a point of clearing
page->private in the tails (though 0 is often what is already there).

But now commit 71e2d666ef ("mm/huge_memory: do not clobber swp_entry_t
during THP split") issues a warning when page_tail->private is found to be
non-0 (unless it's swapcache).

Change that warning to dump page_tail (which also dumps head), instead of
just the head: so far we have seen dead000000000122, dead000000000003,
dead000000000001 or 0000000000000002 in the raw output for tail private.

We could just delete the warning, but today's consensus appears to want
page->private to be 0, unless there's a good reason for it to be set: so
now clear it in prep_compound_tail() (more general than just for THP; but
not for high order allocation, which makes no pass down the tails).

Link: https://lkml.kernel.org/r/1c4233bb-4e4d-5969-fbd4-96604268a285@google.com
Fixes: 71e2d666ef ("mm/huge_memory: do not clobber swp_entry_t during THP split")
Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-28 13:37:22 -07:00
Rik van Riel
8ebe0a5eaa mm,madvise,hugetlb: fix unexpected data loss with MADV_DONTNEED on hugetlbfs
A common use case for hugetlbfs is for the application to create
memory pools backed by huge pages, which then get handed over to
some malloc library (eg. jemalloc) for further management.

That malloc library may be doing MADV_DONTNEED calls on memory
that is no longer needed, expecting those calls to happen on
PAGE_SIZE boundaries.

However, currently the MADV_DONTNEED code rounds up any such
requests to HPAGE_PMD_SIZE boundaries. This leads to undesired
outcomes when jemalloc expects a 4kB MADV_DONTNEED, but 2MB of
memory get zeroed out, instead.

Use of pre-built shared libraries means that user code does not
always know the page size of every memory arena in use.

Avoid unexpected data loss with MADV_DONTNEED by rounding up
only to PAGE_SIZE (in do_madvise), and rounding down to huge
page granularity.

That way programs will only get as much memory zeroed out as
they requested.

Link: https://lkml.kernel.org/r/20221021192805.366ad573@imladris.surriel.com
Fixes: 90e7e7f5ef ("mm: enable MADV_DONTNEED for hugetlb mappings")
Signed-off-by: Rik van Riel <riel@surriel.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-28 13:37:22 -07:00
Maria Yu
fba4eaf931 mm/page_isolation: fix clang deadcode warning
When !CONFIG_VM_BUG_ON, there is warning of
clang-analyzer-deadcode.DeadStores:
Value stored to 'mt' during its initialization is never read.

Link: https://lkml.kernel.org/r/20221021101555.7992-2-quic_aiquny@quicinc.com
Signed-off-by: Maria Yu <quic_aiquny@quicinc.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Doug Berger <opendmb@gmail.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-28 13:37:22 -07:00
Huang Ying
27d676a1c2 memory tier, sysfs: rename attribute "nodes" to "nodelist"
In sysfs, we use attribute name "cpumap" or "cpus" for cpu mask and
"cpulist" or "cpus_list" for cpu list.  For example, in my system,

 $ cat /sys/devices/system/node/node0/cpumap
 f,ffffffff
 $ cat /sys/devices/system/cpu/cpu2/topology/core_cpus
 0,00100004
 $ cat cat /sys/devices/system/node/node0/cpulist
 0-35
 $ cat /sys/devices/system/cpu/cpu2/topology/core_cpus_list
 2,20

It looks reasonable to use "nodemap" for node mask and "nodelist" for
node list.  So, rename the attribute to follow the naming convention.

Link: https://lkml.kernel.org/r/20221020015122.290097-1-ying.huang@intel.com
Fixes: 9832fb8783 ("mm/demotion: expose memory tier details via sysfs")
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Acked-by: Wei Xu <weixugc@google.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Bharata B Rao <bharata@amd.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Hesham Almatary <hesham.almatary@huawei.com>
Cc: Jagdish Gediya <jvgediya.oss@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Tim Chen <tim.c.chen@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-28 13:37:22 -07:00
Waiman Long
984a608377 mm/kmemleak: prevent soft lockup in kmemleak_scan()'s object iteration loops
Commit 6edda04ccc ("mm/kmemleak: prevent soft lockup in first object
iteration loop of kmemleak_scan()") adds cond_resched() in the first
object iteration loop of kmemleak_scan().  However, it turns that the 2nd
objection iteration loop can still cause soft lockup to happen in some
cases.  So add a cond_resched() call in the 2nd and 3rd loops as well to
prevent that and for completeness.

Link: https://lkml.kernel.org/r/20221020175619.366317-1-longman@redhat.com
Fixes: 6edda04ccc ("mm/kmemleak: prevent soft lockup in first object iteration loop of kmemleak_scan()")
Signed-off-by: Waiman Long <longman@redhat.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-28 13:37:22 -07:00
Mel Gorman
71e2d666ef mm/huge_memory: do not clobber swp_entry_t during THP split
The following has been observed when running stressng mmap since commit
b653db7735 ("mm: Clear page->private when splitting or migrating a page")

   watchdog: BUG: soft lockup - CPU#75 stuck for 26s! [stress-ng:9546]
   CPU: 75 PID: 9546 Comm: stress-ng Tainted: G            E      6.0.0-revert-b653db77-fix+ #29 0357d79b60fb09775f678e4f3f64ef0579ad1374
   Hardware name: SGI.COM C2112-4GP3/X10DRT-P-Series, BIOS 2.0a 05/09/2016
   RIP: 0010:xas_descend+0x28/0x80
   Code: cc cc 0f b6 0e 48 8b 57 08 48 d3 ea 83 e2 3f 89 d0 48 83 c0 04 48 8b 44 c6 08 48 89 77 18 48 89 c1 83 e1 03 48 83 f9 02 75 08 <48> 3d fd 00 00 00 76 08 88 57 12 c3 cc cc cc cc 48 c1 e8 02 89 c2
   RSP: 0018:ffffbbf02a2236a8 EFLAGS: 00000246
   RAX: ffff9cab7d6a0002 RBX: ffffe04b0af88040 RCX: 0000000000000002
   RDX: 0000000000000030 RSI: ffff9cab60509b60 RDI: ffffbbf02a2236c0
   RBP: 0000000000000000 R08: ffff9cab60509b60 R09: ffffbbf02a2236c0
   R10: 0000000000000001 R11: ffffbbf02a223698 R12: 0000000000000000
   R13: ffff9cab4e28da80 R14: 0000000000039c01 R15: ffff9cab4e28da88
   FS:  00007fab89b85e40(0000) GS:ffff9cea3fcc0000(0000) knlGS:0000000000000000
   CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
   CR2: 00007fab84e00000 CR3: 00000040b73a4003 CR4: 00000000003706e0
   DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
   DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
   Call Trace:
    <TASK>
    xas_load+0x3a/0x50
    __filemap_get_folio+0x80/0x370
    ? put_swap_page+0x163/0x360
    pagecache_get_page+0x13/0x90
    __try_to_reclaim_swap+0x50/0x190
    scan_swap_map_slots+0x31e/0x670
    get_swap_pages+0x226/0x3c0
    folio_alloc_swap+0x1cc/0x240
    add_to_swap+0x14/0x70
    shrink_page_list+0x968/0xbc0
    reclaim_page_list+0x70/0xf0
    reclaim_pages+0xdd/0x120
    madvise_cold_or_pageout_pte_range+0x814/0xf30
    walk_pgd_range+0x637/0xa30
    __walk_page_range+0x142/0x170
    walk_page_range+0x146/0x170
    madvise_pageout+0xb7/0x280
    ? asm_common_interrupt+0x22/0x40
    madvise_vma_behavior+0x3b7/0xac0
    ? find_vma+0x4a/0x70
    ? find_vma+0x64/0x70
    ? madvise_vma_anon_name+0x40/0x40
    madvise_walk_vmas+0xa6/0x130
    do_madvise+0x2f4/0x360
    __x64_sys_madvise+0x26/0x30
    do_syscall_64+0x5b/0x80
    ? do_syscall_64+0x67/0x80
    ? syscall_exit_to_user_mode+0x17/0x40
    ? do_syscall_64+0x67/0x80
    ? syscall_exit_to_user_mode+0x17/0x40
    ? do_syscall_64+0x67/0x80
    ? do_syscall_64+0x67/0x80
    ? common_interrupt+0x8b/0xa0
    entry_SYSCALL_64_after_hwframe+0x63/0xcd

The problem can be reproduced with the mmtests config
config-workload-stressng-mmap.  It does not always happen and when it
triggers is variable but it has happened on multiple machines.

The intent of commit b653db7735 patch was to avoid the case where
PG_private is clear but folio->private is not-NULL.  However, THP tail
pages uses page->private for "swp_entry_t if folio_test_swapcache()" as
stated in the documentation for struct folio.  This patch only clobbers
page->private for tail pages if the head page was not in swapcache and
warns once if page->private had an unexpected value.

Link: https://lkml.kernel.org/r/20221019134156.zjyyn5aownakvztf@techsingularity.net
Fixes: b653db7735 ("mm: Clear page->private when splitting or migrating a page")
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Brian Foster <bfoster@redhat.com>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Oleksandr Natalenko <oleksandr@natalenko.name>
Cc: Seth Jennings <sjenning@redhat.com>
Cc: Vitaly Wool <vitaly.wool@konsulko.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-20 21:27:24 -07:00
Mike Kravetz
612b8a3170 hugetlb: fix memory leak associated with vma_lock structure
The hugetlb vma_lock structure hangs off the vm_private_data pointer of
sharable hugetlb vmas.  The structure is vma specific and can not be
shared between vmas.  At fork and various other times, vmas are duplicated
via vm_area_dup().  When this happens, the pointer in the newly created
vma must be cleared and the structure reallocated.  Two hugetlb specific
routines deal with this hugetlb_dup_vma_private and hugetlb_vm_op_open. 
Both routines are called for newly created vmas.  hugetlb_dup_vma_private
would always clear the pointer and hugetlb_vm_op_open would allocate the
new vms_lock structure.  This did not work in the case of this calling
sequence pointed out in [1].

  move_vma
    copy_vma
      new_vma = vm_area_dup(vma);
      new_vma->vm_ops->open(new_vma); --> new_vma has its own vma lock.
    is_vm_hugetlb_page(vma)
      clear_vma_resv_huge_pages
        hugetlb_dup_vma_private --> vma->vm_private_data is set to NULL

When clearing hugetlb_dup_vma_private we actually leak the associated
vma_lock structure.

The vma_lock structure contains a pointer to the associated vma.  This
information can be used in hugetlb_dup_vma_private and hugetlb_vm_op_open
to ensure we only clear the vm_private_data of newly created (copied)
vmas.  In such cases, the vma->vma_lock->vma field will not point to the
vma.

Update hugetlb_dup_vma_private and hugetlb_vm_op_open to not clear
vm_private_data if vma->vma_lock->vma == vma.  Also, log a warning if
hugetlb_vm_op_open ever encounters the case where vma_lock has already
been correctly allocated for the vma.

[1] https://lore.kernel.org/linux-mm/5154292a-4c55-28cd-0935-82441e512fc3@huawei.com/

Link: https://lkml.kernel.org/r/20221019201957.34607-1-mike.kravetz@oracle.com
Fixes: 131a79b474 ("hugetlb: fix vma lock handling during split vma and range unmapping")
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: James Houghton <jthoughton@google.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mina Almasry <almasrymina@google.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Naoya Horiguchi <naoya.horiguchi@linux.dev>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Prakash Sangappa <prakash.sangappa@oracle.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-20 21:27:23 -07:00
Liam R. Howlett
df48a5f7a3 mm/page_alloc: reduce potential fragmentation in make_alloc_exact()
Try to avoid using the left over split page on the next request for a page
by calling __free_pages_ok() with FPI_TO_TAIL.  This increases the
potential of defragmenting memory when it's used for a short period of
time.

Link: https://lkml.kernel.org/r/20220531185626.yvlmymbxyoe5vags@revolver
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Suggested-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-20 21:27:23 -07:00
Rik van Riel
12df140f0b mm,hugetlb: take hugetlb_lock before decrementing h->resv_huge_pages
The h->*_huge_pages counters are protected by the hugetlb_lock, but
alloc_huge_page has a corner case where it can decrement the counter
outside of the lock.

This could lead to a corrupted value of h->resv_huge_pages, which we have
observed on our systems.

Take the hugetlb_lock before decrementing h->resv_huge_pages to avoid a
potential race.

Link: https://lkml.kernel.org/r/20221017202505.0e6a4fcd@imladris.surriel.com
Fixes: a88c769548 ("mm: hugetlb: fix hugepage memory leak caused by wrong reserve count")
Signed-off-by: Rik van Riel <riel@surriel.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Glen McCready <gkmccready@meta.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-20 21:27:23 -07:00
Liam Howlett
a57b70519d mm/mmap: fix MAP_FIXED address return on VMA merge
mmap should return the start address of newly mapped area when successful.
On a successful merge of a VMA, the return address was changed and thus
was violating that expectation from userspace.

This is a restoration of functionality provided by 309d08d9b3
(mm/mmap.c: fix mmap return value when vma is merged after call_mmap()). 
For completeness of fixing MAP_FIXED, implement the comments from the
previous discussion to never update the address and fail if the address
changes.  Leaving the error as a WARN_ON() to avoid crashing the kernel.

Link: https://lkml.kernel.org/r/20221018191613.4133459-1-Liam.Howlett@oracle.com
Link: https://lore.kernel.org/all/Y06yk66SKxlrwwfb@lakrids/
Link: https://lore.kernel.org/all/20201203085350.22624-1-liuzixian4@huawei.com/
Fixes: 4dd1b84140 ("mm/mmap: use advanced maple tree API for mmap_region()")
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Reported-by: Mark Rutland <mark.rutland@arm.com>
Cc: Liu Zixian <liuzixian4@huawei.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-20 21:27:23 -07:00
Andrew Morton
1cd916d034 mm/mmap.c: __vma_adjust(): suppress uninitialized var warning
The code is OK, but it fools gcc.

mm/mmap.c:802 __vma_adjust() error: uninitialized symbol 'next_next'.

Fixes: 524e00b36e ("mm: remove rb tree.")
Reported-by: kernel test robot <lkp@intel.com>
Cc: Liam R. Howlett <Liam.Howlett@Oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-20 21:27:23 -07:00