linux/arch
Mel Gorman a9c8e4beee xen: properly account for _PAGE_NUMA during xen pte translations
Steven Noonan forwarded a users report where they had a problem starting
vsftpd on a Xen paravirtualized guest, with this in dmesg:

  BUG: Bad page map in process vsftpd  pte:8000000493b88165 pmd:e9cc01067
  page:ffffea00124ee200 count:0 mapcount:-1 mapping:     (null) index:0x0
  page flags: 0x2ffc0000000014(referenced|dirty)
  addr:00007f97eea74000 vm_flags:00100071 anon_vma:ffff880e98f80380 mapping:          (null) index:7f97eea74
  CPU: 4 PID: 587 Comm: vsftpd Not tainted 3.12.7-1-ec2 #1
  Call Trace:
    dump_stack+0x45/0x56
    print_bad_pte+0x22e/0x250
    unmap_single_vma+0x583/0x890
    unmap_vmas+0x65/0x90
    exit_mmap+0xc5/0x170
    mmput+0x65/0x100
    do_exit+0x393/0x9e0
    do_group_exit+0xcc/0x140
    SyS_exit_group+0x14/0x20
    system_call_fastpath+0x1a/0x1f
  Disabling lock debugging due to kernel taint
  BUG: Bad rss-counter state mm:ffff880e9ca60580 idx:0 val:-1
  BUG: Bad rss-counter state mm:ffff880e9ca60580 idx:1 val:1

The issue could not be reproduced under an HVM instance with the same
kernel, so it appears to be exclusive to paravirtual Xen guests.  He
bisected the problem to commit 1667918b64 ("mm: numa: clear numa
hinting information on mprotect") that was also included in 3.12-stable.

The problem was related to how xen translates ptes because it was not
accounting for the _PAGE_NUMA bit.  This patch splits pte_present to add
a pteval_present helper for use by xen so both bare metal and xen use
the same code when checking if a PTE is present.

[mgorman@suse.de: wrote changelog, proposed minor modifications]
[akpm@linux-foundation.org: fix typo in comment]
Reported-by: Steven Noonan <steven@uplinklabs.net>
Tested-by: Steven Noonan <steven@uplinklabs.net>
Signed-off-by: Elena Ufimtseva <ufimtseva@gmail.com>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: <stable@vger.kernel.org>	[3.12+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-02-10 16:01:41 -08:00
..
alpha alpha: fix broken network checksum 2014-01-31 09:21:55 -08:00
arc Merge branch 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild 2014-01-30 16:58:05 -08:00
arm ARM: SoC fixes for 3.14-rc1 2014-02-02 11:11:06 -08:00
arm64 arm64: defconfig: Expand default enabled features 2014-02-07 17:17:28 +00:00
avr32 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2014-01-25 11:17:34 -08:00
blackfin Merge branch 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media 2014-01-31 09:31:14 -08:00
c6x lib: Add missing arch generic-y entries for asm-generic/hash.h 2013-12-17 21:26:19 -05:00
cris CRIS correction for 3.14 2014-01-28 09:01:14 -08:00
frv Merge branch 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild 2014-01-30 16:58:05 -08:00
hexagon Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2014-01-25 11:17:34 -08:00
ia64 [IA64] Wire up new sched_setattr and sched_getattr syscalls 2014-01-28 09:52:53 -08:00
m32r Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2014-01-25 11:17:34 -08:00
m68k Merge branch 'for-3.14/core' of git://git.kernel.dk/linux-block 2014-01-30 11:19:05 -08:00
metag Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2014-01-25 11:17:34 -08:00
microblaze Microblaze patches for 3.14-rc1 2014-01-28 09:04:11 -08:00
mips MIPS: fpu.h: Fix build when CONFIG_BUG is not set 2014-02-06 13:42:43 +01:00
mn10300 Merge branch 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild 2014-01-30 16:58:05 -08:00
openrisc OpenRISC updates for 3.14 2014-01-30 17:08:41 -08:00
parisc execve: use 'struct filename *' for executable name passing 2014-02-05 12:54:53 -08:00
powerpc Second batch of KVM updates. Some minor x86 fixes, 2014-01-31 08:37:32 -08:00
s390 Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2014-02-05 15:51:42 -08:00
score Merge branch 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media 2014-01-31 09:31:14 -08:00
sh Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2014-01-25 11:17:34 -08:00
sparc sparc: Hook up sched_setattr and sched_getattr syscalls. 2014-01-29 00:45:06 -08:00
tile tile: remove compat_sys_lookup_dcookie declaration to fix compile error 2014-02-01 10:55:15 -08:00
um Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml 2014-01-26 11:06:16 -08:00
unicore32 arch/unicore32/kernel/early_printk.c:setup_early_printk: missing initialization 2014-01-27 21:02:39 -08:00
x86 xen: properly account for _PAGE_NUMA during xen pte translations 2014-02-10 16:01:41 -08:00
xtensa Merge branch 'for-3.14/core' of git://git.kernel.dk/linux-block 2014-01-30 11:19:05 -08:00
.gitignore
Kconfig stackprotector: Introduce CONFIG_CC_STACKPROTECTOR_STRONG 2013-12-20 09:38:40 +01:00