Konstantin Khlebnikov 3b09542675 proc/pagemap: walk page tables under pte lock ...

commit 05fbf357d9 upstream.

Lockless access to pte in pagemap_pte_range() might race with page
migration and trigger BUG_ON(!PageLocked()) in migration_entry_to_page():

CPU A (pagemap)                           CPU B (migration)
                                          lock_page()
                                          try_to_unmap(page, TTU_MIGRATION...)
                                               make_migration_entry()
                                               set_pte_at()
<read *pte>
pte_to_pagemap_entry()
                                          remove_migration_ptes()
                                          unlock_page()
    if(is_migration_entry())
        migration_entry_to_page()
            BUG_ON(!PageLocked(page))

Also lockless read might be non-atomic if pte is larger than wordsize.
Other pte walkers (smaps, numa_maps, clear_refs) already lock ptes.

Fixes: 052fb0d635 ("proc: report file/anon bit in /proc/pid/pagemap")
Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Reported-by: Andrey Ryabinin <a.ryabinin@samsung.com>
Reviewed-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: <stable@vger.kernel.org>	[3.5+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

2015-04-29 10:31:56 +02:00

..

array.c

CAPABILITIES: remove undefined caps from all processes

2014-09-17 09:19:09 -07:00

base.c

userns: Add a knob to disable setgroups on a per user namespace basis

2015-01-08 10:00:50 -08:00

cmdline.c

fs/proc: don't use module_init for non-modular core code

2014-01-23 16:37:02 -08:00

consoles.c

fs/proc: don't use module_init for non-modular core code

2014-01-23 16:37:02 -08:00

cpuinfo.c

fs/proc: don't use module_init for non-modular core code

2014-01-23 16:37:02 -08:00

devices.c

fs/proc: don't use module_init for non-modular core code

2014-01-23 16:37:02 -08:00

fd.c

proc: make proc_fd_permission() thread-friendly

2013-09-11 15:59:03 -07:00

fd.h

proc: Move proc_fd() to fs/proc/fd.h

2013-05-01 17:29:39 -04:00

generic.c

procfs: fix race between symlink removals and traversals

2015-03-18 13:31:31 +01:00

inode.c

procfs: fix race between symlink removals and traversals

2015-03-18 13:31:31 +01:00

internal.h

procfs: fix race between symlink removals and traversals

2015-03-18 13:31:31 +01:00

interrupts.c

fs/proc: don't use module_init for non-modular core code

2014-01-23 16:37:02 -08:00

Kconfig

kcore: add Kconfig help text

2013-11-13 12:09:33 +09:00

kcore.c

fs/proc: don't use module_init for non-modular core code

2014-01-23 16:37:02 -08:00

kmsg.c

fs/proc: don't use module_init for non-modular core code

2014-01-23 16:37:02 -08:00

loadavg.c

fs/proc: don't use module_init for non-modular core code

2014-01-23 16:37:02 -08:00

Makefile

mm, vmalloc: move get_vmalloc_info() to vmalloc.c

2013-04-29 15:54:33 -07:00

meminfo.c

fs/proc: don't use module_init for non-modular core code

2014-01-23 16:37:02 -08:00

namespaces.c

consolidate simple ->d_delete() instances

2013-11-15 22:04:17 -05:00

nommu.c

fs/proc: don't use module_init for non-modular core code

2014-01-23 16:37:02 -08:00

page.c

mm: close PageTail race

2014-03-04 07:55:47 -08:00

proc_devtree.c

fs/proc/proc_devtree.c: remove empty /proc/device-tree when no openfirmware exists.

2014-01-23 16:37:01 -08:00

proc_net.c

[readdir] convert procfs

2013-06-29 12:56:32 +04:00

proc_sysctl.c

Don't pass inode to ->d_hash() and ->d_compare()

2013-06-29 12:57:36 +04:00

proc_tty.c

proc: use seq_puts()/seq_putc() where possible

2011-01-13 08:03:16 -08:00

root.c

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace

2013-09-07 14:35:32 -07:00

self.c

new helper: kfree_put_link()

2013-10-24 23:34:49 -04:00

softirqs.c

fs/proc: don't use module_init for non-modular core code

2014-01-23 16:37:02 -08:00

stat.c

genirq: Prevent proc race against freeing of irq descriptors

2015-01-27 08:18:55 -08:00

task_mmu.c

proc/pagemap: walk page tables under pte lock

2015-04-29 10:31:56 +02:00

task_nommu.c

seq_file: remove "%n" usage from seq_file users

2013-11-15 09:32:20 +09:00

uptime.c

fs/proc: don't use module_init for non-modular core code

2014-01-23 16:37:02 -08:00

version.c

fs/proc: don't use module_init for non-modular core code

2014-01-23 16:37:02 -08:00

vmcore.c

vmcore: prevent PT_NOTE p_memsz overflow during header update

2014-02-10 16:01:40 -08:00