Skip to content

GitLab

Switch branch/tag
  1. 25 Oct, 2023 1 commit
  3. 13 Sep, 2023 1 commit
  5. 05 Sep, 2023 1 commit
    • Zqiang's avatar
      rcu: dump vmalloc memory info safely · c83ad36a
      Zqiang authored 
      Currently, for double invoke call_rcu(), will dump rcu_head objects memory
info, if the objects is not allocated from the slab allocator, the
vmalloc_dump_obj() will be invoke and the vmap_area_lock spinlock need to
be held, since the call_rcu() can be invoked in interrupt context,
therefore, there is a possibility of spinlock deadlock scenarios.

And in Preempt-RT kernel, the rcutorture test also trigger the following
lockdep warning:

BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48
in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 1, name: swapper/0
preempt_count: 1, expected: 0
RCU nest depth: 1, expected: 1
3 locks held by swapper/0/1:
 #0: ffffffffb534ee80 (fullstop_mutex){+.+.}-{4:4}, at: torture_init_begin+0x24/0xa0
 #1: ffffffffb5307940 (rcu_read_lock){....}-{1:3}, at: rcu_torture_init+0x1ec7/0x2370
 #2: ffffffffb536af40 (vmap_area_lock){+.+.}-{3:3}, at: find_vmap_area+0x1f/0x70
irq event stamp: 565512
hardirqs last  enabled at (565511): [<ffffffffb379b138>] __call_rcu_common+0x218/0x940
hardirqs last disabled at (565512): [<ffffffffb5804262>] rcu_torture_init+0x20b2/0x2370
softirqs last  enabled at (399112): [<ffffffffb36b2586>] __local_bh_enable_ip+0x126/0x170
softirqs last disabled at (399106): [<ffffffffb43fef59>] inet_register_protosw+0x9/0x1d0
Preemption disabled at:
[<ffffffffb58040c3>] rcu_torture_init+0x1f13/0x2370
CPU: 0 PID: 1 Comm: swapper/0 Tainted: G        W          6.5.0-rc4-rt2-yocto-preempt-rt+ #15
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.2-0-gea1b7a073390-prebuilt.qemu.org 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x68/0xb0
 dump_stack+0x14/0x20
 __might_resched+0x1aa/0x280
 ? __pfx_rcu_torture_err_cb+0x10/0x10
 rt_spin_lock+0x53/0x130
 ? find_vmap_area+0x1f/0x70
 find_vmap_area+0x1f/0x70
 vmalloc_dump_obj+0x20/0x60
 mem_dump_obj+0x22/0x90
 __call_rcu_common+0x5bf/0x940
 ? debug_smp_processor_id+0x1b/0x30
 call_rcu_hurry+0x14/0x20
 rcu_torture_init+0x1f82/0x2370
 ? __pfx_rcu_torture_leak_cb+0x10/0x10
 ? __pfx_rcu_torture_leak_cb+0x10/0x10
 ? __pfx_rcu_torture_init+0x10/0x10
 do_one_initcall+0x6c/0x300
 ? debug_smp_processor_id+0x1b/0x30
 kernel_init_freeable+0x2b9/0x540
 ? __pfx_kernel_init+0x10/0x10
 kernel_init+0x1f/0x150
 ret_from_fork+0x40/0x50
 ? __pfx_kernel_init+0x10/0x10
 ret_from_fork_asm+0x1b/0x30
 </TASK>

The previous patch fixes this by using the deadlock-safe best-effort
version of find_vm_area.  However, in case of failure print the fact that
the pointer was a vmalloc pointer so that we print at least something.

Link: https://lkml.kernel.org/r/20230904180806.1002832-2-joel@joelfernandes.org
Fixes: 98f18083

 ("mm: Make mem_dump_obj() handle vmalloc() memory")
Signed-off-by: default avatarZqiang <qiang.zhang1211@gmail.com>
Signed-off-by: default avatarJoel Fernandes (Google) <joel@joelfernandes.org>
Reported-by: default avatarZhen Lei <thunder.leizhen@huaweicloud.com>
Reviewed-by: default avatarMatthew Wilcox (Oracle) <willy@infradead.org>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      c83ad36a
  7. 24 Aug, 2023 2 commits
  9. 22 Aug, 2023 1 commit
    • Helge Deller's avatar
      parisc: Use generic mmap top-down layout and brk randomization · 3033cd43
      Helge Deller authored 
      
parisc uses a top-down layout by default that exactly fits the generic
functions, so get rid of arch specific code and use the generic version
by selecting ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT.

Note that on parisc the stack always grows up and a "unlimited stack"
simply means that the value as defined in CONFIG_STACK_MAX_DEFAULT_SIZE_MB
should be used. So RLIM_INFINITY is not an indicator to use the legacy
memory layout.
Signed-off-by: default avatarHelge Deller <deller@gmx.de>
      3033cd43
  11. 18 Aug, 2023 1 commit
  13. 11 Jul, 2023 1 commit
  15. 08 Apr, 2023 1 commit
  17. 13 Feb, 2023 1 commit
  19. 19 Jan, 2023 1 commit
  21. 30 Nov, 2022 1 commit
    • Hugh Dickins's avatar
      mm,thp,rmap: simplify compound page mapcount handling · cb67f428
      Hugh Dickins authored 
      Compound page (folio) mapcount calculations have been different for anon
and file (or shmem) THPs, and involved the obscure PageDoubleMap flag. 
And each huge mapping and unmapping of a file (or shmem) THP involved
atomically incrementing and decrementing the mapcount of every subpage of
that huge page, dirtying many struct page cachelines.

Add subpages_mapcount field to the struct folio and first tail page, so
that the total of subpage mapcounts is available in one place near the
head: then page_mapcount() and total_mapcount() and page_mapped(), and
their folio equivalents, are so quick that anon and file and hugetlb don't
need to be optimized differently.  Delete the unloved PageDoubleMap.

page_add and page_remove rmap functions must now maintain the
subpages_mapcount as well as the subpage _mapcount, when dealing with pte
mappings of huge pages; and correct maintenance of NR_ANON_MAPPED and
NR_FILE_MAPPED statistics still needs reading through the subpages, using
nr_subpages_unmapped() - but only when first or last pmd mapping finds
subpages_mapcount raised (double-map case, not the common case).

But are those counts (used to decide when to split an anon THP, and in
vmscan's pagecache_reclaimable heuristic) correctly maintained?  Not
quite: since page_remove_rmap() (and also split_huge_pmd()) is often
called without page lock, there can be races when a subpage pte mapcount
0<->1 while compound pmd mapcount 0<->1 is scanning - races which the
previous implementation had prevented.  The statistics might become
inaccurate, and even drift down until they underflow through 0.  That is
not good enough, but is better dealt with in a followup patch.

Update a few comments on first and second tail page overlaid fields. 
hugepage_add_new_anon_rmap() has to "increment" compound_mapcount, but
subpages_mapcount and compound_pincount are already correctly at 0, so
delete its reinitialization of compound_pincount.

A simple 100 X munmap(mmap(2GB, MAP_SHARED|MAP_POPULATE, tmpfs), 2GB) took
18 seconds on small pages, and used to take 1 second on huge pages, but
now takes 119 milliseconds on huge pages.  Mapping by pmds a second time
used to take 860ms and now takes 92ms; mapping by pmds after mapping by
ptes (when the scan is needed) used to take 870ms and now takes 495ms. 
But there might be some benchmarks which would show a slowdown, because
tail struct pages now fall out of cache until final freeing checks them.

Link: https://lkml.kernel.org/r/47ad693-717-79c8-e1ba-46c3a6602e48@google.com

Signed-off-by: default avatarHugh Dickins <hughd@google.com>
Acked-by: default avatarKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: James Houghton <jthoughton@google.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mina Almasry <almasrymina@google.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Naoya Horiguchi <naoya.horiguchi@linux.dev>
Cc: Peter Xu <peterx@redhat.com>
Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Zach O'Keefe <zokeefe@google.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      cb67f428
  23. 01 Oct, 2022 1 commit
  25. 27 Sep, 2022 2 commits
  27. 12 Sep, 2022 2 commits
  29. 02 Aug, 2022 1 commit
  31. 27 Jun, 2022 1 commit
  33. 19 May, 2022 1 commit
    • Jason A. Donenfeld's avatar
      random: move randomize_page() into mm where it belongs · 5ad7dd88
      Jason A. Donenfeld authored 
      
randomize_page is an mm function. It is documented like one. It contains
the history of one. It has the naming convention of one. It looks
just like another very similar function in mm, randomize_stack_top().
And it has always been maintained and updated by mm people. There is no
need for it to be in random.c. In the "which shape does not look like
the other ones" test, pointing to randomize_page() is correct.

So move randomize_page() into mm/util.c, right next to the similar
randomize_stack_top() function.

This commit contains no actual code changes.

Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarJason A. Donenfeld <Jason@zx2c4.com>
      5ad7dd88
  35. 10 May, 2022 1 commit
  37. 05 May, 2022 1 commit
  39. 24 Apr, 2022 1 commit
    • Linus Torvalds's avatar
      kvmalloc: use vmalloc_huge for vmalloc allocations · 9becb688
      Linus Torvalds authored 
      Since commit 559089e0 ("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 3b8000ae
("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 f2edd118:
"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: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      9becb688
  41. 21 Mar, 2022 2 commits
  43. 08 Mar, 2022 1 commit
  45. 04 Mar, 2022 1 commit
    • Daniel Borkmann's avatar
      mm: Consider __GFP_NOWARN flag for oversized kvmalloc() calls · 0708a0af
      Daniel Borkmann authored 
      syzkaller was recently triggering an oversized kvmalloc() warning via
xdp_umem_create().

The triggered warning was added back in 7661809d ("mm: don't allow
oversized kvmalloc() calls"). The rationale for the warning for huge
kvmalloc sizes was as a reaction to a security bug where the size was
more than UINT_MAX but not everything was prepared to handle unsigned
long sizes.

Anyway, the AF_XDP related call trace from this syzkaller report was:

  kvmalloc include/linux/mm.h:806 [inline]
  kvmalloc_array include/linux/mm.h:824 [inline]
  kvcalloc include/linux/mm.h:829 [inline]
  xdp_umem_pin_pages net/xdp/xdp_umem.c:102 [inline]
  xdp_umem_reg net/xdp/xdp_umem.c:219 [inline]
  xdp_umem_create+0x6a5/0xf00 net/xdp/xdp_umem.c:252
  xsk_setsockopt+0x604/0x790 net/xdp/xsk.c:1068
  __sys_setsockopt+0x1fd/0x4e0 net/socket.c:2176
  __do_sys_setsockopt net/socket.c:2187 [inline]
  __se_sys_setsockopt net/socket.c:2184 [inline]
  __x64_sys_setsockopt+0xb5/0x150 net/socket.c:2184
  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+0x44/0xae

Björn mentioned that requests for >2GB allocation can still be valid:

  The structure that is being allocated is the page-pinning accounting.
  AF_XDP has an internal limit of U32_MAX pages, which is *a lot*, but
  still fewer than what memcg allows (PAGE_COUNTER_MAX is a LONG_MAX/
  PAGE_SIZE on 64 bit systems). [...]

  I could just change from U32_MAX to INT_MAX, but as I stated earlier
  that has a hacky feeling to it. [...] From my perspective, the code
  isn't broken, with the memcg limits in consideration. [...]

Linus says:

  [...] Pretty much every time this has come up, the kernel warning has
  shown that yes, the code was broken and there really wasn't a reason
  for doing allocations that big.

  Of course, some people would be perfectly fine with the allocation
  failing, they just don't want the warning. I didn't want __GFP_NOWARN
  to shut it up originally because I wanted people to see all those
  cases, but these days I think we can just say "yeah, people can shut
  it up explicitly by saying 'go ahead and fail this allocation, don't
  warn about it'".

  So enough time has passed that by now I'd certainly be ok with [it].

Thus allow call-sites to silence such userspace triggered splats if the
allocation requests have __GFP_NOWARN. For xdp_umem_pin_pages()'s call
to kvcalloc() this is already the case, so nothing else needed there.

Fixes: 7661809d

 ("mm: don't allow oversized kvmalloc() calls")
Reported-by: syzbot+11421fbbff99b989670e@syzkaller.appspotmail.com
Suggested-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Tested-by: syzbot+11421fbbff99b989670e@syzkaller.appspotmail.com
Cc: Björn Töpel <bjorn@kernel.org>
Cc: Magnus Karlsson <magnus.karlsson@intel.com>
Cc: Willy Tarreau <w@1wt.eu>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: David S. Miller <davem@davemloft.net>
Link: https://lore.kernel.org/bpf/CAJ+HfNhyfsT5cS_U9EC213ducHs9k9zNxX9+abqC0kTrPbQ0gg@mail.gmail.com
Link: https://lore.kernel.org/bpf/20211201202905.b9892171e3f5b9a60f9da251@linux-foundation.org

Reviewed-by: default avatarLeon Romanovsky <leonro@nvidia.com>
Ackd-by: default avatarMichal Hocko <mhocko@suse.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      0708a0af
  47. 15 Jan, 2022 1 commit
  49. 17 Nov, 2021 1 commit
  51. 18 Oct, 2021 2 commits
  53. 27 Sep, 2021 3 commits
  55. 24 Sep, 2021 1 commit
    • Chen Jun's avatar
      mm: fix uninitialized use in overcommit_policy_handler · bcbda810
      Chen Jun authored 
      We get an unexpected value of /proc/sys/vm/overcommit_memory after
running the following program:

  int main()
  {
      int fd = open("/proc/sys/vm/overcommit_memory", O_RDWR);
      write(fd, "1", 1);
      write(fd, "2", 1);
      close(fd);
  }

write(fd, "2", 1) will pass *ppos = 1 to proc_dointvec_minmax.
proc_dointvec_minmax will return 0 without setting new_policy.

  t.data = &new_policy;
  ret = proc_dointvec_minmax(&t, write, buffer, lenp, ppos)
      -->do_proc_dointvec
         -->__do_proc_dointvec
              if (write) {
                if (proc_first_pos_non_zero_ignore(ppos, table))
                  goto out;

  sysctl_overcommit_memory = new_policy;

so sysctl_overcommit_memory will be set to an uninitialized value.

Check whether new_policy has been changed by proc_dointvec_minmax.

Link: https://lkml.kernel.org/r/20210923020524.13289-1-chenjun102@huawei.com
Fixes: 56f3547b ("mm: adjust vm_committed_as_batch according to vm...
      bcbda810
  57. 02 Sep, 2021 1 commit
    • Linus Torvalds's avatar
      mm: don't allow oversized kvmalloc() calls · 7661809d
      Linus Torvalds authored 
      
'kvmalloc()' is a convenience function for people who want to do a
kmalloc() but fall back on vmalloc() if there aren't enough physically
contiguous pages, or if the allocation is larger than what kmalloc()
supports.

However, let's make sure it doesn't get _too_ easy to do crazy things
with it.  In particular, don't allow big allocations that could be due
to integer overflow or underflow.  So make sure the allocation size fits
in an 'int', to protect against trivial integer conversion issues.
Acked-by: default avatarWilly Tarreau <w@1wt.eu>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      7661809d
  59. 09 Aug, 2021 1 commit
    • Dave Chinner's avatar
      mm: Add kvrealloc() · de2860f4
      Dave Chinner authored 
      During log recovery of an XFS filesystem with 64kB directory
buffers, rebuilding a buffer split across two log records results
in a memory allocation warning from krealloc like this:

xfs filesystem being mounted at /mnt/scratch supports timestamps until 2038 (0x7fffffff)
XFS (dm-0): Unmounting Filesystem
XFS (dm-0): Mounting V5 Filesystem
XFS (dm-0): Starting recovery (logdev: internal)
------------[ cut here ]------------
WARNING: CPU: 5 PID: 3435170 at mm/page_alloc.c:3539 get_page_from_freelist+0xdee/0xe40
.....
RIP: 0010:get_page_from_freelist+0xdee/0xe40
Call Trace:
 ? complete+0x3f/0x50
 __alloc_pages+0x16f/0x300
 alloc_pages+0x87/0x110
 kmalloc_order+0x2c/0x90
 kmalloc_order_trace+0x1d/0x90
 __kmalloc_track_caller+0x215/0x270
 ? xlog_recover_add_to_cont_trans+0x63/0x1f0
 krealloc+0x54/0xb0
 xlog_recover_add_to_cont_trans+0x63/0x1f0
 xlog_recovery_process_trans+0xc1/0xd0
 xlog_recover_process_ophdr+0x86/0x130
 xlog_recover_process_data+0x9f/0x160
 xlog_recover_process+0xa2/0x120
 xlog_do_recovery_pass+0x40b/0x7d0
 ? __irq_work_queue_local+0x4f/0x60
 ? irq_work_queue+0x3a/0x50
 xlog_do_log_recovery+0x70/0x150
 xlog_do_recover+0x38/0x1d0
 xlog_recover+0xd8/0x170
 xfs_log_mount+0x181/0x300
 xfs_mountfs+0x4a1/0x9b0
 xfs_fs_fill_super+0x3c0/0x7b0
 get_tree_bdev+0x171/0x270
 ? suffix_kstrtoint.constprop.0+0xf0/0xf0
 xfs_fs_get_tree+0x15/0x20
 vfs_get_tree+0x24/0xc0
 path_mount+0x2f5/0xaf0
 __x64_sys_mount+0x108/0x140
 do_syscall_64+0x3a/0x70
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Essentially, we are taking a multi-order allocation from kmem_alloc()
(which has an open coded no fail, no warn loop) and then
reallocating it out to 64kB using krealloc(__GFP_NOFAIL) and that is
then triggering the above warning.

This is a regression caused by converting this code from an open
coded no fail/no warn reallocation loop to using __GFP_NOFAIL.

What we actually need here is kvrealloc(), so that if contiguous
page allocation fails we fall back to vmalloc() and we don't
get nasty warnings happening in XFS.

Fixes: 771915c4

 ("xfs: remove kmem_realloc()")
Signed-off-by: default avatarDave Chinner <dchinner@redhat.com>
Acked-by: default avatarMel Gorman <mgorman@techsingularity.net>
Reviewed-by: default avatarDarrick J. Wong <djwong@kernel.org>
Signed-off-by: default avatarDarrick J. Wong <djwong@kernel.org>
      de2860f4
  61. 12 Jul, 2021 1 commit
  63. 01 Jul, 2021 1 commit
    • David Hildenbrand's avatar
      mm: introduce page_offline_(begin|end|freeze|thaw) to synchronize setting PageOffline() · 82840451
      David Hildenbrand authored 
      A driver might set a page logically offline -- PageOffline() -- and turn
the page inaccessible in the hypervisor; after that, access to page
content can be fatal.  One example is virtio-mem; while unplugged memory
-- marked as PageOffline() can currently be read in the hypervisor, this
will no longer be the case in the future; for example, when having a
virtio-mem device backed by huge pages in the hypervisor.

Some special PFN walkers -- i.e., /proc/kcore -- read content of random
pages after checking PageOffline(); however, these PFN walkers can race
with drivers that set PageOffline().

Let's introduce page_offline_(begin|end|freeze|thaw) for synchronizing.

page_offline_freeze()/page_offline_thaw() allows for a subsystem to
synchronize with such drivers, achieving that a page cannot be set
PageOffline() while frozen.

page_offline_begin()/page_offline_end() is used by drivers that care about
such races when setting a page PageOffline().

For simplicity, use a rwsem for now; neither drivers nor users are
performance sensitive.

Link: https://lkml.kernel.org/r/20210526093041.8800-5-david@redhat.com

Signed-off-by: default avatarDavid Hildenbrand <david@redhat.com>
Acked-by: default avatarMichal Hocko <mhocko@suse.com>
Reviewed-by: default avatarMike Rapoport <rppt@linux.ibm.com>
Reviewed-by: default avatarOscar Salvador <osalvador@suse.de>
Cc: Aili Yao <yaoaili@kingsoft.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Alex Shi <alex.shi@linux.alibaba.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Jiri Bohac <jbohac@suse.cz>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: Steven Price <steven.price@arm.com>
Cc: Wei Liu <wei.liu@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      82840451
  65. 10 May, 2021 1 commit
    • Maninder Singh's avatar
      mm/slub: Add Support for free path information of an object · e548eaa1
      Maninder Singh authored 
      
This commit adds enables a stack dump for the last free of an object:

slab kmalloc-64 start c8ab0140 data offset 64 pointer offset 0 size 64 allocated at meminfo_proc_show+0x40/0x4fc
[   20.192078]     meminfo_proc_show+0x40/0x4fc
[   20.192263]     seq_read_iter+0x18c/0x4c4
[   20.192430]     proc_reg_read_iter+0x84/0xac
[   20.192617]     generic_file_splice_read+0xe8/0x17c
[   20.192816]     splice_direct_to_actor+0xb8/0x290
[   20.193008]     do_splice_direct+0xa0/0xe0
[   20.193185]     do_sendfile+0x2d0/0x438
[   20.193345]     sys_sendfile64+0x12c/0x140
[   20.193523]     ret_fast_syscall+0x0/0x58
[   20.193695]     0xbeeacde4
[   20.193822]  Free path:
[   20.193935]     meminfo_proc_show+0x5c/0x4fc
[   20.194115]     seq_read_iter+0x18c/0x4c4
[   20.194285]     proc_reg_read_iter+0x84/0xac
[   20.194475]     generic_file_splice_read+0xe8/0x17c
[   20.194685]     splice_direct_to_actor+0xb8/0x290
[   20.194870]     do_splice_direct+0xa0/0xe0
[   20.195014]     do_sendfile+0x2d0/0x438
[   20.195174]     sys_sendfile64+0x12c/0x140
[   20.195336]     ret_fast_syscall+0x0/0x58
[   20.195491]     0xbeeacde4
Acked-by: default avatarVlastimil Babka <vbabka@suse.cz>
Co-developed-by: default avatarVaneet Narang <v.narang@samsung.com>
Signed-off-by: default avatarVaneet Narang <v.narang@samsung.com>
Signed-off-by: default avatarManinder Singh <maninder1.s@samsung.com>
Signed-off-by: default avatarPaul E. McKenney <paulmck@kernel.org>
      e548eaa1
GitLab Nexedi Edition | About GitLab | About Nexedi | 沪ICP备2021021310号-2 | 沪ICP备2021021310号-7