Граф коммитов

12259 Коммитов

Автор SHA1 Сообщение Дата
David Rientjes 9d3c3354bb mm, thp: do not cause memcg oom for thp
Commit 2516035499 ("mm, thp: remove __GFP_NORETRY from khugepaged and
madvised allocations") changed the page allocator to no longer detect
thp allocations based on __GFP_NORETRY.

It did not, however, modify the mem cgroup try_charge() path to avoid
oom kill for either khugepaged collapsing or thp faulting.  It is never
expected to oom kill a process to allocate a hugepage for thp; reclaim
is governed by the thp defrag mode and MADV_HUGEPAGE, but allocations
(and charging) should fallback instead of oom killing processes.

Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1803191409420.124411@chino.kir.corp.google.com
Fixes: 2516035499 ("mm, thp: remove __GFP_NORETRY from khugepaged and madvised allocations")
Signed-off-by: David Rientjes <rientjes@google.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-03-22 17:07:02 -07:00
Andrey Ryabinin 1c610d5f93 mm/vmscan: wake up flushers for legacy cgroups too
Commit 726d061fbd ("mm: vmscan: kick flushers when we encounter dirty
pages on the LRU") added flusher invocation to shrink_inactive_list()
when many dirty pages on the LRU are encountered.

However, shrink_inactive_list() doesn't wake up flushers for legacy
cgroup reclaim, so the next commit bbef938429 ("mm: vmscan: remove old
flusher wakeup from direct reclaim path") removed the only source of
flusher's wake up in legacy mem cgroup reclaim path.

This leads to premature OOM if there is too many dirty pages in cgroup:
    # mkdir /sys/fs/cgroup/memory/test
    # echo $$ > /sys/fs/cgroup/memory/test/tasks
    # echo 50M > /sys/fs/cgroup/memory/test/memory.limit_in_bytes
    # dd if=/dev/zero of=tmp_file bs=1M count=100
    Killed

    dd invoked oom-killer: gfp_mask=0x14000c0(GFP_KERNEL), nodemask=(null), order=0, oom_score_adj=0

    Call Trace:
     dump_stack+0x46/0x65
     dump_header+0x6b/0x2ac
     oom_kill_process+0x21c/0x4a0
     out_of_memory+0x2a5/0x4b0
     mem_cgroup_out_of_memory+0x3b/0x60
     mem_cgroup_oom_synchronize+0x2ed/0x330
     pagefault_out_of_memory+0x24/0x54
     __do_page_fault+0x521/0x540
     page_fault+0x45/0x50

    Task in /test killed as a result of limit of /test
    memory: usage 51200kB, limit 51200kB, failcnt 73
    memory+swap: usage 51200kB, limit 9007199254740988kB, failcnt 0
    kmem: usage 296kB, limit 9007199254740988kB, failcnt 0
    Memory cgroup stats for /test: cache:49632KB rss:1056KB rss_huge:0KB shmem:0KB
            mapped_file:0KB dirty:49500KB writeback:0KB swap:0KB inactive_anon:0KB
	    active_anon:1168KB inactive_file:24760KB active_file:24960KB unevictable:0KB
    Memory cgroup out of memory: Kill process 3861 (bash) score 88 or sacrifice child
    Killed process 3876 (dd) total-vm:8484kB, anon-rss:1052kB, file-rss:1720kB, shmem-rss:0kB
    oom_reaper: reaped process 3876 (dd), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB

Wake up flushers in legacy cgroup reclaim too.

Link: http://lkml.kernel.org/r/20180315164553.17856-1-aryabinin@virtuozzo.com
Fixes: bbef938429 ("mm: vmscan: remove old flusher wakeup from direct reclaim path")
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Tested-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Tejun Heo <tj@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-03-22 17:07:01 -07:00
Daniel Vacek f59f1caf72 Revert "mm: page_alloc: skip over regions of invalid pfns where possible"
This reverts commit b92df1de5d ("mm: page_alloc: skip over regions of
invalid pfns where possible").  The commit is meant to be a boot init
speed up skipping the loop in memmap_init_zone() for invalid pfns.

But given some specific memory mapping on x86_64 (or more generally
theoretically anywhere but on arm with CONFIG_HAVE_ARCH_PFN_VALID) the
implementation also skips valid pfns which is plain wrong and causes
'kernel BUG at mm/page_alloc.c:1389!'

  crash> log | grep -e BUG -e RIP -e Call.Trace -e move_freepages_block -e rmqueue -e freelist -A1
  kernel BUG at mm/page_alloc.c:1389!
  invalid opcode: 0000 [#1] SMP
  --
  RIP: 0010: move_freepages+0x15e/0x160
  --
  Call Trace:
    move_freepages_block+0x73/0x80
    __rmqueue+0x263/0x460
    get_page_from_freelist+0x7e1/0x9e0
    __alloc_pages_nodemask+0x176/0x420
  --

  crash> page_init_bug -v | grep RAM
  <struct resource 0xffff88067fffd2f8>          1000 -        9bfff       System RAM (620.00 KiB)
  <struct resource 0xffff88067fffd3a0>        100000 -     430bffff       System RAM (  1.05 GiB = 1071.75 MiB = 1097472.00 KiB)
  <struct resource 0xffff88067fffd410>      4b0c8000 -     4bf9cfff       System RAM ( 14.83 MiB = 15188.00 KiB)
  <struct resource 0xffff88067fffd480>      4bfac000 -     646b1fff       System RAM (391.02 MiB = 400408.00 KiB)
  <struct resource 0xffff88067fffd560>      7b788000 -     7b7fffff       System RAM (480.00 KiB)
  <struct resource 0xffff88067fffd640>     100000000 -    67fffffff       System RAM ( 22.00 GiB)

  crash> page_init_bug | head -6
  <struct resource 0xffff88067fffd560>      7b788000 -     7b7fffff       System RAM (480.00 KiB)
  <struct page 0xffffea0001ede200>   1fffff00000000  0 <struct pglist_data 0xffff88047ffd9000> 1 <struct zone 0xffff88047ffd9800> DMA32          4096    1048575
  <struct page 0xffffea0001ede200>       505736 505344 <struct page 0xffffea0001ed8000> 505855 <struct page 0xffffea0001edffc0>
  <struct page 0xffffea0001ed8000>                0  0 <struct pglist_data 0xffff88047ffd9000> 0 <struct zone 0xffff88047ffd9000> DMA               1       4095
  <struct page 0xffffea0001edffc0>   1fffff00000400  0 <struct pglist_data 0xffff88047ffd9000> 1 <struct zone 0xffff88047ffd9800> DMA32          4096    1048575
  BUG, zones differ!

  crash> kmem -p 77fff000 78000000 7b5ff000 7b600000 7b787000 7b788000
        PAGE        PHYSICAL      MAPPING       INDEX CNT FLAGS
  ffffea0001e00000  78000000                0        0  0 0
  ffffea0001ed7fc0  7b5ff000                0        0  0 0
  ffffea0001ed8000  7b600000                0        0  0 0       <<<<
  ffffea0001ede1c0  7b787000                0        0  0 0
  ffffea0001ede200  7b788000                0        0  1 1fffff00000000

Link: http://lkml.kernel.org/r/20180316143855.29838-1-neelx@redhat.com
Fixes: b92df1de5d ("mm: page_alloc: skip over regions of invalid pfns where possible")
Signed-off-by: Daniel Vacek <neelx@redhat.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Pavel Tatashin <pasha.tatashin@oracle.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-03-22 17:07:01 -07:00
Kirill A. Shutemov b3cd54b257 mm/shmem: do not wait for lock_page() in shmem_unused_huge_shrink()
shmem_unused_huge_shrink() gets called from reclaim path.  Waiting for
page lock may lead to deadlock there.

There was a bug report that may be attributed to this:

  http://lkml.kernel.org/r/alpine.LRH.2.11.1801242349220.30642@mail.ewheeler.net

Replace lock_page() with trylock_page() and skip the page if we failed
to lock it.  We will get to the page on the next scan.

We can test for the PageTransHuge() outside the page lock as we only
need protection against splitting the page under us.  Holding pin oni
the page is enough for this.

Link: http://lkml.kernel.org/r/20180316210830.43738-1-kirill.shutemov@linux.intel.com
Fixes: 779750d20b ("shmem: split huge pages beyond i_size under memory pressure")
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reported-by: Eric Wheeler <linux-mm@lists.ewheeler.net>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Hugh Dickins <hughd@google.com>
Cc: <stable@vger.kernel.org>	[4.8+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-03-22 17:07:01 -07:00
Kirill A. Shutemov fa41b900c3 mm/thp: do not wait for lock_page() in deferred_split_scan()
deferred_split_scan() gets called from reclaim path.  Waiting for page
lock may lead to deadlock there.

Replace lock_page() with trylock_page() and skip the page if we failed
to lock it.  We will get to the page on the next scan.

Link: http://lkml.kernel.org/r/20180315150747.31945-1-kirill.shutemov@linux.intel.com
Fixes: 9a982250f7 ("thp: introduce deferred_split_huge_page()")
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-03-22 17:07:01 -07:00
Kirill A. Shutemov fece2029a9 mm/khugepaged.c: convert VM_BUG_ON() to collapse fail
khugepaged is not yet able to convert PTE-mapped huge pages back to PMD
mapped.  We do not collapse such pages.  See check
khugepaged_scan_pmd().

But if between khugepaged_scan_pmd() and __collapse_huge_page_isolate()
somebody managed to instantiate THP in the range and then split the PMD
back to PTEs we would have a problem --
VM_BUG_ON_PAGE(PageCompound(page)) will get triggered.

It's possible since we drop mmap_sem during collapse to re-take for
write.

Replace the VM_BUG_ON() with graceful collapse fail.

Link: http://lkml.kernel.org/r/20180315152353.27989-1-kirill.shutemov@linux.intel.com
Fixes: b1caa957ae ("khugepaged: ignore pmd tables with THP mapped with ptes")
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Laura Abbott <labbott@redhat.com>
Cc: Jerome Marchand <jmarchan@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-03-22 17:07:01 -07:00
Mike Kravetz 63489f8e82 hugetlbfs: check for pgoff value overflow
A vma with vm_pgoff large enough to overflow a loff_t type when
converted to a byte offset can be passed via the remap_file_pages system
call.  The hugetlbfs mmap routine uses the byte offset to calculate
reservations and file size.

A sequence such as:

  mmap(0x20a00000, 0x600000, 0, 0x66033, -1, 0);
  remap_file_pages(0x20a00000, 0x600000, 0, 0x20000000000000, 0);

will result in the following when task exits/file closed,

  kernel BUG at mm/hugetlb.c:749!
  Call Trace:
    hugetlbfs_evict_inode+0x2f/0x40
    evict+0xcb/0x190
    __dentry_kill+0xcb/0x150
    __fput+0x164/0x1e0
    task_work_run+0x84/0xa0
    exit_to_usermode_loop+0x7d/0x80
    do_syscall_64+0x18b/0x190
    entry_SYSCALL_64_after_hwframe+0x3d/0xa2

The overflowed pgoff value causes hugetlbfs to try to set up a mapping
with a negative range (end < start) that leaves invalid state which
causes the BUG.

The previous overflow fix to this code was incomplete and did not take
the remap_file_pages system call into account.

[mike.kravetz@oracle.com: v3]
  Link: http://lkml.kernel.org/r/20180309002726.7248-1-mike.kravetz@oracle.com
[akpm@linux-foundation.org: include mmdebug.h]
[akpm@linux-foundation.org: fix -ve left shift count on sh]
Link: http://lkml.kernel.org/r/20180308210502.15952-1-mike.kravetz@oracle.com
Fixes: 045c7a3f53 ("hugetlbfs: fix offset overflow in hugetlbfs mmap")
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Reported-by: Nic Losby <blurbdust@gmail.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Yisheng Xie <xieyisheng1@huawei.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-03-22 17:07:01 -07:00
Tetsuo Handa 2e517d6816 lockdep: fix fs_reclaim warning
Dave Jones reported fs_reclaim lockdep warnings.

  ============================================
  WARNING: possible recursive locking detected
  4.15.0-rc9-backup-debug+ #1 Not tainted
  --------------------------------------------
  sshd/24800 is trying to acquire lock:
   (fs_reclaim){+.+.}, at: [<0000000084f438c2>] fs_reclaim_acquire.part.102+0x5/0x30

  but task is already holding lock:
   (fs_reclaim){+.+.}, at: [<0000000084f438c2>] fs_reclaim_acquire.part.102+0x5/0x30

  other info that might help us debug this:
   Possible unsafe locking scenario:

         CPU0
         ----
    lock(fs_reclaim);
    lock(fs_reclaim);

   *** DEADLOCK ***

   May be due to missing lock nesting notation

  2 locks held by sshd/24800:
   #0:  (sk_lock-AF_INET6){+.+.}, at: [<000000001a069652>] tcp_sendmsg+0x19/0x40
   #1:  (fs_reclaim){+.+.}, at: [<0000000084f438c2>] fs_reclaim_acquire.part.102+0x5/0x30

  stack backtrace:
  CPU: 3 PID: 24800 Comm: sshd Not tainted 4.15.0-rc9-backup-debug+ #1
  Call Trace:
   dump_stack+0xbc/0x13f
   __lock_acquire+0xa09/0x2040
   lock_acquire+0x12e/0x350
   fs_reclaim_acquire.part.102+0x29/0x30
   kmem_cache_alloc+0x3d/0x2c0
   alloc_extent_state+0xa7/0x410
   __clear_extent_bit+0x3ea/0x570
   try_release_extent_mapping+0x21a/0x260
   __btrfs_releasepage+0xb0/0x1c0
   btrfs_releasepage+0x161/0x170
   try_to_release_page+0x162/0x1c0
   shrink_page_list+0x1d5a/0x2fb0
   shrink_inactive_list+0x451/0x940
   shrink_node_memcg.constprop.88+0x4c9/0x5e0
   shrink_node+0x12d/0x260
   try_to_free_pages+0x418/0xaf0
   __alloc_pages_slowpath+0x976/0x1790
   __alloc_pages_nodemask+0x52c/0x5c0
   new_slab+0x374/0x3f0
   ___slab_alloc.constprop.81+0x47e/0x5a0
   __slab_alloc.constprop.80+0x32/0x60
   __kmalloc_track_caller+0x267/0x310
   __kmalloc_reserve.isra.40+0x29/0x80
   __alloc_skb+0xee/0x390
   sk_stream_alloc_skb+0xb8/0x340
   tcp_sendmsg_locked+0x8e6/0x1d30
   tcp_sendmsg+0x27/0x40
   inet_sendmsg+0xd0/0x310
   sock_write_iter+0x17a/0x240
   __vfs_write+0x2ab/0x380
   vfs_write+0xfb/0x260
   SyS_write+0xb6/0x140
   do_syscall_64+0x1e5/0xc05
   entry_SYSCALL64_slow_path+0x25/0x25

This warning is caused by commit d92a8cfcb3 ("locking/lockdep:
Rework FS_RECLAIM annotation") which replaced the use of
lockdep_{set,clear}_current_reclaim_state() in __perform_reclaim()
and lockdep_trace_alloc() in slab_pre_alloc_hook() with
fs_reclaim_acquire()/ fs_reclaim_release().

Since __kmalloc_reserve() from __alloc_skb() adds __GFP_NOMEMALLOC |
__GFP_NOWARN to gfp_mask, and all reclaim path simply propagates
__GFP_NOMEMALLOC, fs_reclaim_acquire() in slab_pre_alloc_hook() is
trying to grab the 'fake' lock again when __perform_reclaim() already
grabbed the 'fake' lock.

The

  /* this guy won't enter reclaim */
  if ((current->flags & PF_MEMALLOC) && !(gfp_mask & __GFP_NOMEMALLOC))
          return false;

test which causes slab_pre_alloc_hook() to try to grab the 'fake' lock
was added by commit cf40bd16fd ("lockdep: annotate reclaim context
(__GFP_NOFS)").  But that test is outdated because PF_MEMALLOC thread
won't enter reclaim regardless of __GFP_NOMEMALLOC after commit
341ce06f69 ("page allocator: calculate the alloc_flags for allocation
only once") added the PF_MEMALLOC safeguard (

  /* Avoid recursion of direct reclaim */
  if (p->flags & PF_MEMALLOC)
          goto nopage;

in __alloc_pages_slowpath()).

Thus, let's fix outdated test by removing __GFP_NOMEMALLOC test and
allow __need_fs_reclaim() to return false.

Link: http://lkml.kernel.org/r/201802280650.FJC73911.FOSOMLJVFFQtHO@I-love.SAKURA.ne.jp
Fixes: d92a8cfcb3 ("locking/lockdep: Rework FS_RECLAIM annotation")
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reported-by: Dave Jones <davej@codemonkey.org.uk>
Tested-by: Dave Jones <davej@codemonkey.org.uk>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Nick Piggin <npiggin@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Nikolay Borisov <nborisov@suse.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: <stable@vger.kernel.org>	[4.14+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-03-22 17:07:01 -07:00
Yisheng Xie 8970a63e96 mm/mempolicy.c: avoid use uninitialized preferred_node
Alexander reported a use of uninitialized memory in __mpol_equal(),
which is caused by incorrect use of preferred_node.

When mempolicy in mode MPOL_PREFERRED with flags MPOL_F_LOCAL, it uses
numa_node_id() instead of preferred_node, however, __mpol_equal() uses
preferred_node without checking whether it is MPOL_F_LOCAL or not.

[akpm@linux-foundation.org: slight comment tweak]
Link: http://lkml.kernel.org/r/4ebee1c2-57f6-bcb8-0e2d-1833d1ee0bb7@huawei.com
Fixes: fc36b8d3d8 ("mempolicy: use MPOL_F_LOCAL to Indicate Preferred Local Policy")
Signed-off-by: Yisheng Xie <xieyisheng1@huawei.com>
Reported-by: Alexander Potapenko <glider@google.com>
Tested-by: Alexander Potapenko <glider@google.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Dmitriy Vyukov <dvyukov@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-03-22 17:07:01 -07:00
Linus Torvalds 0d707a2f24 Merge branch 'for-4.16-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu
Pull percpu fixes from Tejun Heo:
 "Late percpu pull request for v4.16-rc6.

   - percpu allocator pool replenishing no longer triggers OOM or
     warning messages.

     Also, the alloc interface now understands __GFP_NORETRY and
     __GFP_NOWARN. This is to allow avoiding OOMs from userland
     triggered actions like bpf map creation.

     Also added cond_resched() in alloc loop.

   - perpcu allocation now can be interrupted by kill sigs to avoid
     deadlocking OOM killer.

   - Added Dennis Zhou as a co-maintainer.

     He has rewritten the area map allocator, understands most of the
     code base and has been responsive for all bug reports"

* 'for-4.16-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu:
  percpu_ref: Update doc to dissuade users from depending on internal RCU grace periods
  mm: Allow to kill tasks doing pcpu_alloc() and waiting for pcpu_balance_workfn()
  percpu: include linux/sched.h for cond_resched()
  percpu: add a schedule point in pcpu_balance_workfn()
  percpu: allow select gfp to be passed to underlying allocators
  percpu: add __GFP_NORETRY semantics to the percpu balancing path
  percpu: match chunk allocator declarations with definitions
  percpu: add Dennis Zhou as a percpu co-maintainer
2018-03-19 14:48:35 -07:00
Kirill Tkhai f52ba1fef7 mm: Allow to kill tasks doing pcpu_alloc() and waiting for pcpu_balance_workfn()
In case of memory deficit and low percpu memory pages,
pcpu_balance_workfn() takes pcpu_alloc_mutex for a long
time (as it makes memory allocations itself and waits
for memory reclaim). If tasks doing pcpu_alloc() are
choosen by OOM killer, they can't exit, because they
are waiting for the mutex.

The patch makes pcpu_alloc() to care about killing signal
and use mutex_lock_killable(), when it's allowed by GFP
flags. This guarantees, a task does not miss SIGKILL
from OOM killer.

Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2018-03-19 09:38:50 -07:00
Tejun Heo 71546d1004 percpu: include linux/sched.h for cond_resched()
microblaze build broke due to missing declaration of the
cond_resched() invocation added recently.  Let's include linux/sched.h
explicitly.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: kbuild test robot <fengguang.wu@intel.com>
2018-03-19 09:38:18 -07:00
Ard Biesheuvel 3e04040df6 Revert "mm/page_alloc: fix memmap_init_zone pageblock alignment"
This reverts commit 864b75f9d6.

Commit 864b75f9d6 ("mm/page_alloc: fix memmap_init_zone pageblock
alignment") modified the logic in memmap_init_zone() to initialize
struct pages associated with invalid PFNs, to appease a VM_BUG_ON()
in move_freepages(), which is redundant by its own admission, and
dereferences struct page fields to obtain the zone without checking
whether the struct pages in question are valid to begin with.

Commit 864b75f9d6 only makes it worse, since the rounding it does
may cause pfn assume the same value it had in a prior iteration of
the loop, resulting in an infinite loop and a hang very early in the
boot. Also, since it doesn't perform the same rounding on start_pfn
itself but only on intermediate values following an invalid PFN, we
may still hit the same VM_BUG_ON() as before.

So instead, let's fix this at the core, and ensure that the BUG
check doesn't dereference struct page fields of invalid pages.

Fixes: 864b75f9d6 ("mm/page_alloc: fix memmap_init_zone pageblock alignment")
Tested-by: Jan Glauber <jglauber@cavium.com>
Tested-by: Shanker Donthineni <shankerd@codeaurora.org>
Cc: Daniel Vacek <neelx@redhat.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Pavel Tatashin <pasha.tatashin@oracle.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-03-14 16:33:28 -07:00
Daniel Vacek 864b75f9d6 mm/page_alloc: fix memmap_init_zone pageblock alignment
Commit b92df1de5d ("mm: page_alloc: skip over regions of invalid pfns
where possible") introduced a bug where move_freepages() triggers a
VM_BUG_ON() on uninitialized page structure due to pageblock alignment.
To fix this, simply align the skipped pfns in memmap_init_zone() the
same way as in move_freepages_block().

Seen in one of the RHEL reports:

  crash> log | grep -e BUG -e RIP -e Call.Trace -e move_freepages_block -e rmqueue -e freelist -A1
  kernel BUG at mm/page_alloc.c:1389!
  invalid opcode: 0000 [#1] SMP
  --
  RIP: 0010:[<ffffffff8118833e>]  [<ffffffff8118833e>] move_freepages+0x15e/0x160
  RSP: 0018:ffff88054d727688  EFLAGS: 00010087
  --
  Call Trace:
   [<ffffffff811883b3>] move_freepages_block+0x73/0x80
   [<ffffffff81189e63>] __rmqueue+0x263/0x460
   [<ffffffff8118c781>] get_page_from_freelist+0x7e1/0x9e0
   [<ffffffff8118caf6>] __alloc_pages_nodemask+0x176/0x420
  --
  RIP  [<ffffffff8118833e>] move_freepages+0x15e/0x160
   RSP <ffff88054d727688>

  crash> page_init_bug -v | grep RAM
  <struct resource 0xffff88067fffd2f8>          1000 -        9bfff	System RAM (620.00 KiB)
  <struct resource 0xffff88067fffd3a0>        100000 -     430bffff	System RAM (  1.05 GiB = 1071.75 MiB = 1097472.00 KiB)
  <struct resource 0xffff88067fffd410>      4b0c8000 -     4bf9cfff	System RAM ( 14.83 MiB = 15188.00 KiB)
  <struct resource 0xffff88067fffd480>      4bfac000 -     646b1fff	System RAM (391.02 MiB = 400408.00 KiB)
  <struct resource 0xffff88067fffd560>      7b788000 -     7b7fffff	System RAM (480.00 KiB)
  <struct resource 0xffff88067fffd640>     100000000 -    67fffffff	System RAM ( 22.00 GiB)

  crash> page_init_bug | head -6
  <struct resource 0xffff88067fffd560>      7b788000 -     7b7fffff	System RAM (480.00 KiB)
  <struct page 0xffffea0001ede200>   1fffff00000000  0 <struct pglist_data 0xffff88047ffd9000> 1 <struct zone 0xffff88047ffd9800> DMA32          4096    1048575
  <struct page 0xffffea0001ede200> 505736 505344 <struct page 0xffffea0001ed8000> 505855 <struct page 0xffffea0001edffc0>
  <struct page 0xffffea0001ed8000>                0  0 <struct pglist_data 0xffff88047ffd9000> 0 <struct zone 0xffff88047ffd9000> DMA               1       4095
  <struct page 0xffffea0001edffc0>   1fffff00000400  0 <struct pglist_data 0xffff88047ffd9000> 1 <struct zone 0xffff88047ffd9800> DMA32          4096    1048575
  BUG, zones differ!

Note that this range follows two not populated sections
68000000-77ffffff in this zone.  7b788000-7b7fffff is the first one
after a gap.  This makes memmap_init_zone() skip all the pfns up to the
beginning of this range.  But this range is not pageblock (2M) aligned.
In fact no range has to be.

  crash> kmem -p 77fff000 78000000 7b5ff000 7b600000 7b787000 7b788000
        PAGE        PHYSICAL      MAPPING       INDEX CNT FLAGS
  ffffea0001e00000  78000000                0        0  0 0
  ffffea0001ed7fc0  7b5ff000                0        0  0 0
  ffffea0001ed8000  7b600000                0        0  0 0	<<<<
  ffffea0001ede1c0  7b787000                0        0  0 0
  ffffea0001ede200  7b788000                0        0  1 1fffff00000000

Top part of page flags should contain nodeid and zonenr, which is not
the case for page ffffea0001ed8000 here (<<<<).

  crash> log | grep -o fffea0001ed[^\ ]* | sort -u
  fffea0001ed8000
  fffea0001eded20
  fffea0001edffc0

  crash> bt -r | grep -o fffea0001ed[^\ ]* | sort -u
  fffea0001ed8000
  fffea0001eded00
  fffea0001eded20
  fffea0001edffc0

Initialization of the whole beginning of the section is skipped up to
the start of the range due to the commit b92df1de5d.  Now any code
calling move_freepages_block() (like reusing the page from a freelist as
in this example) with a page from the beginning of the range will get
the page rounded down to start_page ffffea0001ed8000 and passed to
move_freepages() which crashes on assertion getting wrong zonenr.

  >         VM_BUG_ON(page_zone(start_page) != page_zone(end_page));

Note, page_zone() derives the zone from page flags here.

From similar machine before commit b92df1de5d28:

  crash> kmem -p 77fff000 78000000 7b5ff000 7b600000 7b7fe000 7b7ff000
        PAGE        PHYSICAL      MAPPING       INDEX CNT FLAGS
  fffff73941e00000  78000000                0        0  1 1fffff00000000
  fffff73941ed7fc0  7b5ff000                0        0  1 1fffff00000000
  fffff73941ed8000  7b600000                0        0  1 1fffff00000000
  fffff73941edff80  7b7fe000                0        0  1 1fffff00000000
  fffff73941edffc0  7b7ff000 ffff8e67e04d3ae0     ad84  1 1fffff00020068 uptodate,lru,active,mappedtodisk

All the pages since the beginning of the section are initialized.
move_freepages()' not gonna blow up.

The same machine with this fix applied:

  crash> kmem -p 77fff000 78000000 7b5ff000 7b600000 7b7fe000 7b7ff000
        PAGE        PHYSICAL      MAPPING       INDEX CNT FLAGS
  ffffea0001e00000  78000000                0        0  0 0
  ffffea0001e00000  7b5ff000                0        0  0 0
  ffffea0001ed8000  7b600000                0        0  1 1fffff00000000
  ffffea0001edff80  7b7fe000                0        0  1 1fffff00000000
  ffffea0001edffc0  7b7ff000 ffff88017fb13720        8  2 1fffff00020068 uptodate,lru,active,mappedtodisk

At least the bare minimum of pages is initialized preventing the crash
as well.

Customers started to report this as soon as 7.4 (where b92df1de5d was
merged in RHEL) was released.  I remember reports from
September/October-ish times.  It's not easily reproduced and happens on
a handful of machines only.  I guess that's why.  But that does not make
it less serious, I think.

Though there actually is a report here:
  https://bugzilla.kernel.org/show_bug.cgi?id=196443

And there are reports for Fedora from July:
  https://bugzilla.redhat.com/show_bug.cgi?id=1473242
and CentOS:
  https://bugs.centos.org/view.php?id=13964
and we internally track several dozens reports for RHEL bug
  https://bugzilla.redhat.com/show_bug.cgi?id=1525121

Link: http://lkml.kernel.org/r/0485727b2e82da7efbce5f6ba42524b429d0391a.1520011945.git.neelx@redhat.com
Fixes: b92df1de5d ("mm: page_alloc: skip over regions of invalid pfns where possible")
Signed-off-by: Daniel Vacek <neelx@redhat.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Pavel Tatashin <pasha.tatashin@oracle.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-03-09 16:40:01 -08:00
Daniel Vacek 379b03b7fa mm/memblock.c: hardcode the end_pfn being -1
This is just a cleanup.  It aids handling the special end case in the
next commit.

[akpm@linux-foundation.org: make it work against current -linus, not against -mm]
[akpm@linux-foundation.org: make it work against current -linus, not against -mm some more]
Link: http://lkml.kernel.org/r/1ca478d4269125a99bcfb1ca04d7b88ac1aee924.1520011944.git.neelx@redhat.com
Signed-off-by: Daniel Vacek <neelx@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Pavel Tatashin <pasha.tatashin@oracle.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-03-09 16:40:01 -08:00
Andrea Arcangeli 96312e6128 mm/gup.c: teach get_user_pages_unlocked to handle FOLL_NOWAIT
KVM is hanging during postcopy live migration with userfaultfd because
get_user_pages_unlocked is not capable to handle FOLL_NOWAIT.

Earlier FOLL_NOWAIT was only ever passed to get_user_pages.

Specifically faultin_page (the callee of get_user_pages_unlocked caller)
doesn't know that if FAULT_FLAG_RETRY_NOWAIT was set in the page fault
flags, when VM_FAULT_RETRY is returned, the mmap_sem wasn't actually
released (even if nonblocking is not NULL).  So it sets *nonblocking to
zero and the caller won't release the mmap_sem thinking it was already
released, but it wasn't because of FOLL_NOWAIT.

Link: http://lkml.kernel.org/r/20180302174343.5421-2-aarcange@redhat.com
Fixes: ce53053ce3 ("kvm: switch get_user_page_nowait() to get_user_pages_unlocked()")
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Reported-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Tested-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-03-09 16:40:01 -08:00
Michal Hocko 4704dea36d hugetlb: fix surplus pages accounting
Dan Rue has noticed that libhugetlbfs test suite fails counter test:

  # mount_point="/mnt/hugetlb/"
  # echo 200 > /proc/sys/vm/nr_hugepages
  # mkdir -p "${mount_point}"
  # mount -t hugetlbfs hugetlbfs "${mount_point}"
  # export LD_LIBRARY_PATH=/root/libhugetlbfs/libhugetlbfs-2.20/obj64
  # /root/libhugetlbfs/libhugetlbfs-2.20/tests/obj64/counters
  Starting testcase "/root/libhugetlbfs/libhugetlbfs-2.20/tests/obj64/counters", pid 3319
  Base pool size: 0
  Clean...
  FAIL    Line 326: Bad HugePages_Total: expected 0, actual 1

The bug was bisected to 0c397daea1 ("mm, hugetlb: further simplify
hugetlb allocation API").

The reason is that alloc_surplus_huge_page() misaccounts per node
surplus pages.  We should increase surplus_huge_pages_node rather than
nr_huge_pages_node which is already handled by alloc_fresh_huge_page.

Link: http://lkml.kernel.org/r/20180221191439.GM2231@dhcp22.suse.cz
Fixes: 0c397daea1 ("mm, hugetlb: further simplify hugetlb allocation API")
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reported-by: Dan Rue <dan.rue@linaro.org>
Tested-by: Dan Rue <dan.rue@linaro.org>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-03-09 16:40:01 -08:00
Eric Dumazet accd4f36a7 percpu: add a schedule point in pcpu_balance_workfn()
When a large BPF percpu map is destroyed, I have seen
pcpu_balance_workfn() holding cpu for hundreds of milliseconds.

On KASAN config and 112 hyperthreads, average time to destroy a chunk
is ~4 ms.

[ 2489.841376] destroy chunk 1 in 4148689 ns
...
[ 2490.093428] destroy chunk 32 in 4072718 ns

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2018-02-23 08:52:34 -08:00
Juergen Gross 895f7b8e90 mm: don't defer struct page initialization for Xen pv guests
Commit f7f99100d8 ("mm: stop zeroing memory during allocation in
vmemmap") broke Xen pv domains in some configurations, as the "Pinned"
information in struct page of early page tables could get lost.

This will lead to the kernel trying to write directly into the page
tables instead of asking the hypervisor to do so.  The result is a crash
like the following:

  BUG: unable to handle kernel paging request at ffff8801ead19008
  IP: xen_set_pud+0x4e/0xd0
  PGD 1c0a067 P4D 1c0a067 PUD 23a0067 PMD 1e9de0067 PTE 80100001ead19065
  Oops: 0003 [#1] PREEMPT SMP
  Modules linked in:
  CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.14.0-default+ #271
  Hardware name: Dell Inc. Latitude E6440/0159N7, BIOS A07 06/26/2014
  task: ffffffff81c10480 task.stack: ffffffff81c00000
  RIP: e030:xen_set_pud+0x4e/0xd0
  Call Trace:
   __pmd_alloc+0x128/0x140
   ioremap_page_range+0x3f4/0x410
   __ioremap_caller+0x1c3/0x2e0
   acpi_os_map_iomem+0x175/0x1b0
   acpi_tb_acquire_table+0x39/0x66
   acpi_tb_validate_table+0x44/0x7c
   acpi_tb_verify_temp_table+0x45/0x304
   acpi_reallocate_root_table+0x12d/0x141
   acpi_early_init+0x4d/0x10a
   start_kernel+0x3eb/0x4a1
   xen_start_kernel+0x528/0x532
  Code: 48 01 e8 48 0f 42 15 a2 fd be 00 48 01 d0 48 ba 00 00 00 00 00 ea ff ff 48 c1 e8 0c 48 c1 e0 06 48 01 d0 48 8b 00 f6 c4 02 75 5d <4c> 89 65 00 5b 5d 41 5c c3 65 8b 05 52 9f fe 7e 89 c0 48 0f a3
  RIP: xen_set_pud+0x4e/0xd0 RSP: ffffffff81c03cd8
  CR2: ffff8801ead19008
  ---[ end trace 38eca2e56f1b642e ]---

Avoid this problem by not deferring struct page initialization when
running as Xen pv guest.

Pavel said:

: This is unique for Xen, so this particular issue won't effect other
: configurations.  I am going to investigate if there is a way to
: re-enable deferred page initialization on xen guests.

[akpm@linux-foundation.org: explicitly include xen.h]
Link: http://lkml.kernel.org/r/20180216154101.22865-1-jgross@suse.com
Fixes: f7f99100d8 ("mm: stop zeroing memory during allocation in vmemmap")
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Cc: Steven Sistare <steven.sistare@oracle.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Bob Picco <bob.picco@oracle.com>
Cc: <stable@vger.kernel.org>	[4.15.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-21 15:35:43 -08:00
Michal Hocko 698d0831ba vmalloc: fix __GFP_HIGHMEM usage for vmalloc_32 on 32b systems
Kai Heng Feng has noticed that BUG_ON(PageHighMem(pg)) triggers in
drivers/media/common/saa7146/saa7146_core.c since 19809c2da2 ("mm,
vmalloc: use __GFP_HIGHMEM implicitly").

saa7146_vmalloc_build_pgtable uses vmalloc_32 and it is reasonable to
expect that the resulting page is not in highmem.  The above commit
aimed to add __GFP_HIGHMEM only for those requests which do not specify
any zone modifier gfp flag.  vmalloc_32 relies on GFP_VMALLOC32 which
should do the right thing.  Except it has been missed that GFP_VMALLOC32
is an alias for GFP_KERNEL on 32b architectures.  Thanks to Matthew to
notice this.

Fix the problem by unconditionally setting GFP_DMA32 in GFP_VMALLOC32
for !64b arches (as a bailout).  This should do the right thing and use
ZONE_NORMAL which should be always below 4G on 32b systems.

Debugged by Matthew Wilcox.

[akpm@linux-foundation.org: coding-style fixes]
Link: http://lkml.kernel.org/r/20180212095019.GX21609@dhcp22.suse.cz
Fixes: 19809c2da2 ("mm, vmalloc: use __GFP_HIGHMEM implicitly”)
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reported-by: Kai Heng Feng <kai.heng.feng@canonical.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Laura Abbott <labbott@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-21 15:35:43 -08:00
Mike Rapoport cb6f0f3480 mm/swap.c: make functions and their kernel-doc agree (again)
There was a conflict between the commit e02a9f048e ("mm/swap.c: make
functions and their kernel-doc agree") and the commit f144c390f9 ("mm:
docs: fix parameter names mismatch") that both tried to fix mismatch
betweeen pagevec_lookup_entries() parameter names and their description.

Since nr_entries is a better name for the parameter, fix the description
again.

Link: http://lkml.kernel.org/r/1518116946-20947-1-git-send-email-rppt@linux.vnet.ibm.com
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-21 15:35:43 -08:00
Mike Rapoport 14fec9eba4 mm/zpool.c: zpool_evictable: fix mismatch in parameter name and kernel-doc
[akpm@linux-foundation.org: add colon, per Randy]
Link: http://lkml.kernel.org/r/1518116984-21141-1-git-send-email-rppt@linux.vnet.ibm.com
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-21 15:35:43 -08:00
Huang Ying 7ba716698c mm, swap, frontswap: fix THP swap if frontswap enabled
It was reported by Sergey Senozhatsky that if THP (Transparent Huge
Page) and frontswap (via zswap) are both enabled, when memory goes low
so that swap is triggered, segfault and memory corruption will occur in
random user space applications as follow,

kernel: urxvt[338]: segfault at 20 ip 00007fc08889ae0d sp 00007ffc73a7fc40 error 6 in libc-2.26.so[7fc08881a000+1ae000]
 #0  0x00007fc08889ae0d _int_malloc (libc.so.6)
 #1  0x00007fc08889c2f3 malloc (libc.so.6)
 #2  0x0000560e6004bff7 _Z14rxvt_wcstoutf8PKwi (urxvt)
 #3  0x0000560e6005e75c n/a (urxvt)
 #4  0x0000560e6007d9f1 _ZN16rxvt_perl_interp6invokeEP9rxvt_term9hook_typez (urxvt)
 #5  0x0000560e6003d988 _ZN9rxvt_term9cmd_parseEv (urxvt)
 #6  0x0000560e60042804 _ZN9rxvt_term6pty_cbERN2ev2ioEi (urxvt)
 #7  0x0000560e6005c10f _Z17ev_invoke_pendingv (urxvt)
 #8  0x0000560e6005cb55 ev_run (urxvt)
 #9  0x0000560e6003b9b9 main (urxvt)
 #10 0x00007fc08883af4a __libc_start_main (libc.so.6)
 #11 0x0000560e6003f9da _start (urxvt)

After bisection, it was found the first bad commit is bd4c82c22c ("mm,
THP, swap: delay splitting THP after swapped out").

The root cause is as follows:

When the pages are written to swap device during swapping out in
swap_writepage(), zswap (fontswap) is tried to compress the pages to
improve performance.  But zswap (frontswap) will treat THP as a normal
page, so only the head page is saved.  After swapping in, tail pages
will not be restored to their original contents, causing memory
corruption in the applications.

This is fixed by refusing to save page in the frontswap store functions
if the page is a THP.  So that the THP will be swapped out to swap
device.

Another choice is to split THP if frontswap is enabled.  But it is found
that the frontswap enabling isn't flexible.  For example, if
CONFIG_ZSWAP=y (cannot be module), frontswap will be enabled even if
zswap itself isn't enabled.

Frontswap has multiple backends, to make it easy for one backend to
enable THP support, the THP checking is put in backend frontswap store
functions instead of the general interfaces.

Link: http://lkml.kernel.org/r/20180209084947.22749-1-ying.huang@intel.com
Fixes: bd4c82c22c ("mm, THP, swap: delay splitting THP after swapped out")
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Reported-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Tested-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Suggested-by: Minchan Kim <minchan@kernel.org>	[put THP checking in backend]
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Seth Jennings <sjenning@redhat.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Shaohua Li <shli@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: <stable@vger.kernel.org>	[4.14]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-21 15:35:43 -08:00
Shakeel Butt 9c4e6b1a70 mm, mlock, vmscan: no more skipping pagevecs
When a thread mlocks an address space backed either by file pages which
are currently not present in memory or swapped out anon pages (not in
swapcache), a new page is allocated and added to the local pagevec
(lru_add_pvec), I/O is triggered and the thread then sleeps on the page.
On I/O completion, the thread can wake on a different CPU, the mlock
syscall will then sets the PageMlocked() bit of the page but will not be
able to put that page in unevictable LRU as the page is on the pagevec
of a different CPU.  Even on drain, that page will go to evictable LRU
because the PageMlocked() bit is not checked on pagevec drain.

The page will eventually go to right LRU on reclaim but the LRU stats
will remain skewed for a long time.

This patch puts all the pages, even unevictable, to the pagevecs and on
the drain, the pages will be added on their LRUs correctly by checking
their evictability.  This resolves the mlocked pages on pagevec of other
CPUs issue because when those pagevecs will be drained, the mlocked file
pages will go to unevictable LRU.  Also this makes the race with munlock
easier to resolve because the pagevec drains happen in LRU lock.

However there is still one place which makes a page evictable and does
PageLRU check on that page without LRU lock and needs special attention.
TestClearPageMlocked() and isolate_lru_page() in clear_page_mlock().

	#0: __pagevec_lru_add_fn	#1: clear_page_mlock

	SetPageLRU()			if (!TestClearPageMlocked())
					  return
	smp_mb() // <--required
					// inside does PageLRU
	if (!PageMlocked())		if (isolate_lru_page())
	  move to evictable LRU		  putback_lru_page()
	else
	  move to unevictable LRU

In '#1', TestClearPageMlocked() provides full memory barrier semantics
and thus the PageLRU check (inside isolate_lru_page) can not be
reordered before it.

In '#0', without explicit memory barrier, the PageMlocked() check can be
reordered before SetPageLRU().  If that happens, '#0' can put a page in
unevictable LRU and '#1' might have just cleared the Mlocked bit of that
page but fails to isolate as PageLRU fails as '#0' still hasn't set
PageLRU bit of that page.  That page will be stranded on the unevictable
LRU.

There is one (good) side effect though.  Without this patch, the pages
allocated for System V shared memory segment are added to evictable LRUs
even after shmctl(SHM_LOCK) on that segment.  This patch will correctly
put such pages to unevictable LRU.

Link: http://lkml.kernel.org/r/20171121211241.18877-1-shakeelb@google.com
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Greg Thelen <gthelen@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Shaohua Li <shli@fb.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Hugh Dickins <hughd@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-21 15:35:42 -08:00
Dennis Zhou 554fef1c39 percpu: allow select gfp to be passed to underlying allocators
The prior patch added support for passing gfp flags through to the
underlying allocators. This patch allows users to pass along gfp flags
(currently only __GFP_NORETRY and __GFP_NOWARN) to the underlying
allocators. This should allow users to decide if they are ok with
failing allocations recovering in a more graceful way.

Additionally, gfp passing was done as additional flags in the previous
patch. Instead, change this to caller passed semantics. GFP_KERNEL is
also removed as the default flag. It continues to be used for internally
caused underlying percpu allocations.

V2:
Removed gfp_percpu_mask in favor of doing it inline.
Removed GFP_KERNEL as a default flag for __alloc_percpu_gfp.

Signed-off-by: Dennis Zhou <dennisszhou@gmail.com>
Suggested-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2018-02-18 05:33:01 -08:00
Dennis Zhou 47504ee04b percpu: add __GFP_NORETRY semantics to the percpu balancing path
Percpu memory using the vmalloc area based chunk allocator lazily
populates chunks by first requesting the full virtual address space
required for the chunk and subsequently adding pages as allocations come
through. To ensure atomic allocations can succeed, a workqueue item is
used to maintain a minimum number of empty pages. In certain scenarios,
such as reported in [1], it is possible that physical memory becomes
quite scarce which can result in either a rather long time spent trying
to find free pages or worse, a kernel panic.

This patch adds support for __GFP_NORETRY and __GFP_NOWARN passing them
through to the underlying allocators. This should prevent any
unnecessary panics potentially caused by the workqueue item. The passing
of gfp around is as additional flags rather than a full set of flags.
The next patch will change these to caller passed semantics.

V2:
Added const modifier to gfp flags in the balance path.
Removed an extra whitespace.

[1] https://lkml.org/lkml/2018/2/12/551

Signed-off-by: Dennis Zhou <dennisszhou@gmail.com>
Suggested-by: Daniel Borkmann <daniel@iogearbox.net>
Reported-by: syzbot+adb03f3f0bb57ce3acda@syzkaller.appspotmail.com
Acked-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2018-02-18 05:33:00 -08:00
Dennis Zhou 15d9f3d116 percpu: match chunk allocator declarations with definitions
At some point the function declaration parameters got out of sync with
the function definitions in percpu-vm.c and percpu-km.c. This patch
makes them match again.

Signed-off-by: Dennis Zhou <dennisszhou@gmail.com>
Acked-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2018-02-18 05:33:00 -08:00
Arnd Bergmann af27d9403f mm: hide a #warning for COMPILE_TEST
We get a warning about some slow configurations in randconfig kernels:

  mm/memory.c:83:2: error: #warning Unfortunate NUMA and NUMA Balancing config, growing page-frame for last_cpupid. [-Werror=cpp]

The warning is reasonable by itself, but gets in the way of randconfig
build testing, so I'm hiding it whenever CONFIG_COMPILE_TEST is set.

The warning was added in 2013 in commit 75980e97da ("mm: fold
page->_last_nid into page->flags where possible").

Cc: stable@vger.kernel.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-16 09:41:36 -08:00
Linus Torvalds e525de3ab0 Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Ingo Molnar:
 "Misc fixes all across the map:

   - /proc/kcore vsyscall related fixes
   - LTO fix
   - build warning fix
   - CPU hotplug fix
   - Kconfig NR_CPUS cleanups
   - cpu_has() cleanups/robustification
   - .gitignore fix
   - memory-failure unmapping fix
   - UV platform fix"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/mm, mm/hwpoison: Don't unconditionally unmap kernel 1:1 pages
  x86/error_inject: Make just_return_func() globally visible
  x86/platform/UV: Fix GAM Range Table entries less than 1GB
  x86/build: Add arch/x86/tools/insn_decoder_test to .gitignore
  x86/smpboot: Fix uncore_pci_remove() indexing bug when hot-removing a physical CPU
  x86/mm/kcore: Add vsyscall page to /proc/kcore conditionally
  vfs/proc/kcore, x86/mm/kcore: Fix SMAP fault when dumping vsyscall user page
  x86/Kconfig: Further simplify the NR_CPUS config
  x86/Kconfig: Simplify NR_CPUS config
  x86/MCE: Fix build warning introduced by "x86: do not use print_symbol()"
  x86/cpufeature: Update _static_cpu_has() to use all named variables
  x86/cpufeature: Reindent _static_cpu_has()
2018-02-14 17:31:51 -08:00
Tony Luck fd0e786d9d x86/mm, mm/hwpoison: Don't unconditionally unmap kernel 1:1 pages
In the following commit:

  ce0fa3e56a ("x86/mm, mm/hwpoison: Clear PRESENT bit for kernel 1:1 mappings of poison pages")

... we added code to memory_failure() to unmap the page from the
kernel 1:1 virtual address space to avoid speculative access to the
page logging additional errors.

But memory_failure() may not always succeed in taking the page offline,
especially if the page belongs to the kernel.  This can happen if
there are too many corrected errors on a page and either mcelog(8)
or drivers/ras/cec.c asks to take a page offline.

Since we remove the 1:1 mapping early in memory_failure(), we can
end up with the page unmapped, but still in use. On the next access
the kernel crashes :-(

There are also various debug paths that call memory_failure() to simulate
occurrence of an error. Since there is no actual error in memory, we
don't need to map out the page for those cases.

Revert most of the previous attempt and keep the solution local to
arch/x86/kernel/cpu/mcheck/mce.c. Unmap the page only when:

	1) there is a real error
	2) memory_failure() succeeds.

All of this only applies to 64-bit systems. 32-bit kernel doesn't map
all of memory into kernel space. It isn't worth adding the code to unmap
the piece that is mapped because nobody would run a 32-bit kernel on a
machine that has recoverable machine checks.

Signed-off-by: Tony Luck <tony.luck@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave <dave.hansen@intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Robert (Persistent Memory) <elliott@hpe.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-mm@kvack.org
Cc: stable@vger.kernel.org #v4.14
Fixes: ce0fa3e56a ("x86/mm, mm/hwpoison: Clear PRESENT bit for kernel 1:1 mappings of poison pages")
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-02-13 16:25:06 +01:00
Linus Torvalds a9a08845e9 vfs: do bulk POLL* -> EPOLL* replacement
This is the mindless scripted replacement of kernel use of POLL*
variables as described by Al, done by this script:

    for V in IN OUT PRI ERR RDNORM RDBAND WRNORM WRBAND HUP RDHUP NVAL MSG; do
        L=`git grep -l -w POLL$V | grep -v '^t' | grep -v /um/ | grep -v '^sa' | grep -v '/poll.h$'|grep -v '^D'`
        for f in $L; do sed -i "-es/^\([^\"]*\)\(\<POLL$V\>\)/\\1E\\2/" $f; done
    done

with de-mangling cleanups yet to come.

NOTE! On almost all architectures, the EPOLL* constants have the same
values as the POLL* constants do.  But they keyword here is "almost".
For various bad reasons they aren't the same, and epoll() doesn't
actually work quite correctly in some cases due to this on Sparc et al.

The next patch from Al will sort out the final differences, and we
should be all done.

Scripted-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-11 14:34:03 -08:00
Linus Torvalds a2e5790d84 Merge branch 'akpm' (patches from Andrew)
Merge misc updates from Andrew Morton:

 - kasan updates

 - procfs

 - lib/bitmap updates

 - other lib/ updates

 - checkpatch tweaks

 - rapidio

 - ubsan

 - pipe fixes and cleanups

 - lots of other misc bits

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (114 commits)
  Documentation/sysctl/user.txt: fix typo
  MAINTAINERS: update ARM/QUALCOMM SUPPORT patterns
  MAINTAINERS: update various PALM patterns
  MAINTAINERS: update "ARM/OXNAS platform support" patterns
  MAINTAINERS: update Cortina/Gemini patterns
  MAINTAINERS: remove ARM/CLKDEV SUPPORT file pattern
  MAINTAINERS: remove ANDROID ION pattern
  mm: docs: add blank lines to silence sphinx "Unexpected indentation" errors
  mm: docs: fix parameter names mismatch
  mm: docs: fixup punctuation
  pipe: read buffer limits atomically
  pipe: simplify round_pipe_size()
  pipe: reject F_SETPIPE_SZ with size over UINT_MAX
  pipe: fix off-by-one error when checking buffer limits
  pipe: actually allow root to exceed the pipe buffer limits
  pipe, sysctl: remove pipe_proc_fn()
  pipe, sysctl: drop 'min' parameter from pipe-max-size converter
  kasan: rework Kconfig settings
  crash_dump: is_kdump_kernel can be boolean
  kernel/mutex: mutex_is_locked can be boolean
  ...
2018-02-06 22:15:42 -08:00
Mike Rapoport a5d09bed7f mm: docs: add blank lines to silence sphinx "Unexpected indentation" errors
Link: http://lkml.kernel.org/r/1516700871-22279-4-git-send-email-rppt@linux.vnet.ibm.com
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-06 18:32:48 -08:00
Mike Rapoport f144c390f9 mm: docs: fix parameter names mismatch
There are several places where parameter descriptions do no match the
actual code.  Fix it.

Link: http://lkml.kernel.org/r/1516700871-22279-3-git-send-email-rppt@linux.vnet.ibm.com
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-06 18:32:48 -08:00
Mike Rapoport b7701a5f2e mm: docs: fixup punctuation
so that kernel-doc will properly recognize the parameter and function
descriptions.

Link: http://lkml.kernel.org/r/1516700871-22279-2-git-send-email-rppt@linux.vnet.ibm.com
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-06 18:32:48 -08:00
Yaowei Bai 937f0c2675 mm/memblock: memblock_is_map/region_memory can be boolean
Make memblock_is_map/region_memory return bool due to these two
functions only using either true or false as its return value.

No functional change.

Link: http://lkml.kernel.org/r/1513266622-15860-2-git-send-email-baiyaowei@cmss.chinamobile.com
Signed-off-by: Yaowei Bai <baiyaowei@cmss.chinamobile.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-06 18:32:47 -08:00
Sergey Senozhatsky e7c98df598 mm: remove unneeded kallsyms include
The file was converted from print_symbol() to %pSR a while ago in commit
071361d347 ("mm: Convert print_symbol to %pSR").  kallsyms does not
seem to be needed anymore.

Link: http://lkml.kernel.org/r/20171208025616.16267-3-sergey.senozhatsky@gmail.com
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-06 18:32:47 -08:00
Pravin Shedge 4fd39c23fe mm/userfaultfd.c: remove duplicate include
These duplicate includes have been found with scripts/checkincludes.pl but
they have been removed manually to avoid removing false positives.

Link: http://lkml.kernel.org/r/1512580957-6071-1-git-send-email-pravin.shedge4linux@gmail.com
Signed-off-by: Pravin Shedge <pravin.shedge4linux@gmail.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-06 18:32:47 -08:00
Mike Rapoport 2ee0826085 pids: introduce find_get_task_by_vpid() helper
There are several functions that do find_task_by_vpid() followed by
get_task_struct().  We can use a helper function instead.

Link: http://lkml.kernel.org/r/1509602027-11337-1-git-send-email-rppt@linux.vnet.ibm.com
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-06 18:32:46 -08:00
Andrey Konovalov 5f21f3a8f4 kasan: fix prototype author email address
Use the new one.

Link: http://lkml.kernel.org/r/de3b7ffc30a55178913a7d3865216aa7accf6c40.1515775666.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-06 18:32:43 -08:00
Dmitry Vyukov b1d5728939 kasan: detect invalid frees
Detect frees of pointers into middle of heap objects.

Link: http://lkml.kernel.org/r/cb569193190356beb018a03bb8d6fbae67e7adbc.1514378558.git.dvyukov@google.com
Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>a
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-06 18:32:43 -08:00
Dmitry Vyukov 1db0e0f9dd kasan: unify code between kasan_slab_free() and kasan_poison_kfree()
Both of these functions deal with freeing of slab objects.
However, kasan_poison_kfree() mishandles SLAB_TYPESAFE_BY_RCU
(must also not poison such objects) and does not detect double-frees.

Unify code between these functions.

This solves both of the problems and allows to add more common code
(e.g. detection of invalid frees).

Link: http://lkml.kernel.org/r/385493d863acf60408be219a021c3c8e27daa96f.1514378558.git.dvyukov@google.com
Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>a
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-06 18:32:43 -08:00
Dmitry Vyukov 6860f6340c kasan: detect invalid frees for large mempool objects
Detect frees of pointers into middle of mempool objects.

I did a one-off test, but it turned out to be very tricky, so I reverted
it.  First, mempool does not call kasan_poison_kfree() unless allocation
function fails.  I stubbed an allocation function to fail on second and
subsequent allocations.  But then mempool stopped to call
kasan_poison_kfree() at all, because it does it only when allocation
function is mempool_kmalloc().  We could support this special failing
test allocation function in mempool, but it also can't live with kasan
tests, because these are in a module.

Link: http://lkml.kernel.org/r/bf7a7d035d7a5ed62d2dd0e3d2e8a4fcdf456aa7.1514378558.git.dvyukov@google.com
Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>a
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-06 18:32:43 -08:00
Dmitry Vyukov ee3ce779b5 kasan: don't use __builtin_return_address(1)
__builtin_return_address(1) is unreliable without frame pointers.
With defconfig on kmalloc_pagealloc_invalid_free test I am getting:

BUG: KASAN: double-free or invalid-free in           (null)

Pass caller PC from callers explicitly.

Link: http://lkml.kernel.org/r/9b01bc2d237a4df74ff8472a3bf6b7635908de01.1514378558.git.dvyukov@google.com
Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>a
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-06 18:32:43 -08:00
Dmitry Vyukov 47adccce3e kasan: detect invalid frees for large objects
Patch series "kasan: detect invalid frees".

KASAN detects double-frees, but does not detect invalid-frees (when a
pointer into a middle of heap object is passed to free).  We recently had
a very unpleasant case in crypto code which freed an inner object inside
of a heap allocation.  This left unnoticed during free, but totally
corrupted heap and later lead to a bunch of random crashes all over kernel
code.

Detect invalid frees.

This patch (of 5):

Detect frees of pointers into middle of large heap objects.

I dropped const from kasan_kfree_large() because it starts propagating
through a bunch of functions in kasan_report.c, slab/slub nearest_obj(),
all of their local variables, fixup_red_left(), etc.

Link: http://lkml.kernel.org/r/1b45b4fe1d20fc0de1329aab674c1dd973fee723.1514378558.git.dvyukov@google.com
Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>a
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-06 18:32:42 -08:00
Alexander Potapenko d321599cf6 kasan: add functions for unpoisoning stack variables
As a code-size optimization, LLVM builds since r279383 may bulk-manipulate
the shadow region when (un)poisoning large memory blocks.  This requires
new callbacks that simply do an uninstrumented memset().

This fixes linking the Clang-built kernel when using KASAN.

[arnd@arndb.de: add declarations for internal functions]
  Link: http://lkml.kernel.org/r/20180105094112.2690475-1-arnd@arndb.de
[fengguang.wu@intel.com: __asan_set_shadow_00 can be static]
  Link: http://lkml.kernel.org/r/20171223125943.GA74341@lkp-ib03
[ghackmann@google.com: fix memset() parameters, and tweak commit message to describe new callbacks]
Link: http://lkml.kernel.org/r/20171204191735.132544-6-paullawrence@google.com
Signed-off-by: Alexander Potapenko <glider@google.com>
Signed-off-by: Greg Hackmann <ghackmann@google.com>
Signed-off-by: Paul Lawrence <paullawrence@google.com>
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-06 18:32:42 -08:00
Paul Lawrence 342061ee4e kasan: support alloca() poisoning
clang's AddressSanitizer implementation adds redzones on either side of
alloca()ed buffers.  These redzones are 32-byte aligned and at least 32
bytes long.

__asan_alloca_poison() is passed the size and address of the allocated
buffer, *excluding* the redzones on either side.  The left redzone will
always be to the immediate left of this buffer; but AddressSanitizer may
need to add padding between the end of the buffer and the right redzone.
If there are any 8-byte chunks inside this padding, we should poison
those too.

__asan_allocas_unpoison() is just passed the top and bottom of the dynamic
stack area, so unpoisoning is simpler.

Link: http://lkml.kernel.org/r/20171204191735.132544-4-paullawrence@google.com
Signed-off-by: Greg Hackmann <ghackmann@google.com>
Signed-off-by: Paul Lawrence <paullawrence@google.com>
Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-06 18:32:42 -08:00
Linus Torvalds 3ff1b28caa libnvdimm for 4.16
* Require struct page by default for filesystem DAX to remove a number of
   surprising failure cases.  This includes failures with direct I/O, gdb and
   fork(2).
 
 * Add support for the new Platform Capabilities Structure added to the NFIT in
   ACPI 6.2a.  This new table tells us whether the platform supports flushing
   of CPU and memory controller caches on unexpected power loss events.
 
 * Revamp vmem_altmap and dev_pagemap handling to clean up code and better
   support future future PCI P2P uses.
 
 * Deprecate the ND_IOCTL_SMART_THRESHOLD command whose payload has become
   out-of-sync with recent versions of the NVDIMM_FAMILY_INTEL spec, and
   instead rely on the generic ND_CMD_CALL approach used by the two other IOCTL
   families, NVDIMM_FAMILY_{HPE,MSFT}.
 
 * Enhance nfit_test so we can test some of the new things added in version 1.6
   of the DSM specification.  This includes testing firmware download and
   simulating the Last Shutdown State (LSS) status.
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Merge tag 'libnvdimm-for-4.16' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm

Pull libnvdimm updates from Ross Zwisler:

 - Require struct page by default for filesystem DAX to remove a number
   of surprising failure cases. This includes failures with direct I/O,
   gdb and fork(2).

 - Add support for the new Platform Capabilities Structure added to the
   NFIT in ACPI 6.2a. This new table tells us whether the platform
   supports flushing of CPU and memory controller caches on unexpected
   power loss events.

 - Revamp vmem_altmap and dev_pagemap handling to clean up code and
   better support future future PCI P2P uses.

 - Deprecate the ND_IOCTL_SMART_THRESHOLD command whose payload has
   become out-of-sync with recent versions of the NVDIMM_FAMILY_INTEL
   spec, and instead rely on the generic ND_CMD_CALL approach used by
   the two other IOCTL families, NVDIMM_FAMILY_{HPE,MSFT}.

 - Enhance nfit_test so we can test some of the new things added in
   version 1.6 of the DSM specification. This includes testing firmware
   download and simulating the Last Shutdown State (LSS) status.

* tag 'libnvdimm-for-4.16' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (37 commits)
  libnvdimm, namespace: remove redundant initialization of 'nd_mapping'
  acpi, nfit: fix register dimm error handling
  libnvdimm, namespace: make min namespace size 4K
  tools/testing/nvdimm: force nfit_test to depend on instrumented modules
  libnvdimm/nfit_test: adding support for unit testing enable LSS status
  libnvdimm/nfit_test: add firmware download emulation
  nfit-test: Add platform cap support from ACPI 6.2a to test
  libnvdimm: expose platform persistence attribute for nd_region
  acpi: nfit: add persistent memory control flag for nd_region
  acpi: nfit: Add support for detect platform CPU cache flush on power loss
  device-dax: Fix trailing semicolon
  libnvdimm, btt: fix uninitialized err_lock
  dax: require 'struct page' by default for filesystem dax
  ext2: auto disable dax instead of failing mount
  ext4: auto disable dax instead of failing mount
  mm, dax: introduce pfn_t_special()
  mm: Fix devm_memremap_pages() collision handling
  mm: Fix memory size alignment in devm_memremap_pages_release()
  memremap: merge find_dev_pagemap into get_dev_pagemap
  memremap: change devm_memremap_pages interface to use struct dev_pagemap
  ...
2018-02-06 10:41:33 -08:00
Linus Torvalds 617aebe6a9 Currently, hardened usercopy performs dynamic bounds checking on slab
cache objects. This is good, but still leaves a lot of kernel memory
 available to be copied to/from userspace in the face of bugs. To further
 restrict what memory is available for copying, this creates a way to
 whitelist specific areas of a given slab cache object for copying to/from
 userspace, allowing much finer granularity of access control. Slab caches
 that are never exposed to userspace can declare no whitelist for their
 objects, thereby keeping them unavailable to userspace via dynamic copy
 operations. (Note, an implicit form of whitelisting is the use of constant
 sizes in usercopy operations and get_user()/put_user(); these bypass all
 hardened usercopy checks since these sizes cannot change at runtime.)
 
 This new check is WARN-by-default, so any mistakes can be found over the
 next several releases without breaking anyone's system.
 
 The series has roughly the following sections:
 - remove %p and improve reporting with offset
 - prepare infrastructure and whitelist kmalloc
 - update VFS subsystem with whitelists
 - update SCSI subsystem with whitelists
 - update network subsystem with whitelists
 - update process memory with whitelists
 - update per-architecture thread_struct with whitelists
 - update KVM with whitelists and fix ioctl bug
 - mark all other allocations as not whitelisted
 - update lkdtm for more sensible test overage
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Merge tag 'usercopy-v4.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull hardened usercopy whitelisting from Kees Cook:
 "Currently, hardened usercopy performs dynamic bounds checking on slab
  cache objects. This is good, but still leaves a lot of kernel memory
  available to be copied to/from userspace in the face of bugs.

  To further restrict what memory is available for copying, this creates
  a way to whitelist specific areas of a given slab cache object for
  copying to/from userspace, allowing much finer granularity of access
  control.

  Slab caches that are never exposed to userspace can declare no
  whitelist for their objects, thereby keeping them unavailable to
  userspace via dynamic copy operations. (Note, an implicit form of
  whitelisting is the use of constant sizes in usercopy operations and
  get_user()/put_user(); these bypass all hardened usercopy checks since
  these sizes cannot change at runtime.)

  This new check is WARN-by-default, so any mistakes can be found over
  the next several releases without breaking anyone's system.

  The series has roughly the following sections:
   - remove %p and improve reporting with offset
   - prepare infrastructure and whitelist kmalloc
   - update VFS subsystem with whitelists
   - update SCSI subsystem with whitelists
   - update network subsystem with whitelists
   - update process memory with whitelists
   - update per-architecture thread_struct with whitelists
   - update KVM with whitelists and fix ioctl bug
   - mark all other allocations as not whitelisted
   - update lkdtm for more sensible test overage"

* tag 'usercopy-v4.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (38 commits)
  lkdtm: Update usercopy tests for whitelisting
  usercopy: Restrict non-usercopy caches to size 0
  kvm: x86: fix KVM_XEN_HVM_CONFIG ioctl
  kvm: whitelist struct kvm_vcpu_arch
  arm: Implement thread_struct whitelist for hardened usercopy
  arm64: Implement thread_struct whitelist for hardened usercopy
  x86: Implement thread_struct whitelist for hardened usercopy
  fork: Provide usercopy whitelisting for task_struct
  fork: Define usercopy region in thread_stack slab caches
  fork: Define usercopy region in mm_struct slab caches
  net: Restrict unwhitelisted proto caches to size 0
  sctp: Copy struct sctp_sock.autoclose to userspace using put_user()
  sctp: Define usercopy region in SCTP proto slab cache
  caif: Define usercopy region in caif proto slab cache
  ip: Define usercopy region in IP proto slab cache
  net: Define usercopy region in struct proto slab cache
  scsi: Define usercopy region in scsi_sense_cache slab cache
  cifs: Define usercopy region in cifs_request slab cache
  vxfs: Define usercopy region in vxfs_inode slab cache
  ufs: Define usercopy region in ufs_inode_cache slab cache
  ...
2018-02-03 16:25:42 -08:00
Ross Zwisler ee95f4059a Merge branch 'for-4.16/nfit' into libnvdimm-for-next 2018-02-03 00:26:26 -07:00