linux/arch
Dominik Dingel 2faee8ff9d s390/mm: prevent and break zero page mappings in case of storage keys
As soon as storage keys are enabled we need to stop working on zero page
mappings to prevent inconsistencies between storage keys and pgste.

Otherwise following data corruption could happen:
1) guest enables storage key
2) guest sets storage key for not mapped page X
   -> change goes to PGSTE
3) guest reads from page X
   -> as X was not dirty before, the page will be zero page backed,
      storage key from PGSTE for X will go to storage key for zero page
4) guest sets storage key for not mapped page Y (same logic as above
5) guest reads from page Y
   -> as Y was not dirty before, the page will be zero page backed,
      storage key from PGSTE for Y will got to storage key for zero page
      overwriting storage key for X

While holding the mmap sem, we are safe against changes on entries we
already fixed, as every fault would need to take the mmap_sem (read).

Other vCPUs executing storage key instructions will get a one time interception
and be serialized also with mmap_sem.

Signed-off-by: Dominik Dingel <dingel@linux.vnet.ibm.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2014-10-27 13:27:25 +01:00
..
alpha Merge git://git.infradead.org/users/eparis/audit 2014-10-19 16:25:56 -07:00
arc The "weak" attribute is commonly used for the default version of a 2014-10-23 15:04:27 -07:00
arm ARM: SoC fixes for -rc2 2014-10-26 11:35:51 -07:00
arm64 arm64 fixes: 2014-10-24 12:48:04 -07:00
avr32 Merge branch 'for-linus' of git://git.infradead.org/users/vkoul/slave-dma 2014-10-18 18:11:04 -07:00
blackfin Merge branch 'for-3.18-consistent-ops' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu 2014-10-15 07:48:18 +02:00
c6x
cris Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2014-10-13 16:23:15 +02:00
frv frv: remove unused declarations of __start___ex_table and __stop___ex_table 2014-10-14 02:18:28 +02:00
hexagon Merge branch 'locking-arch-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2014-10-13 15:48:00 +02:00
ia64 Merge branch 'x86-efi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2014-10-23 14:45:09 -07:00
m32r Merge branch 'locking-arch-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2014-10-13 15:48:00 +02:00
m68k Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gerg/m68knommu 2014-10-14 03:51:22 +02:00
metag Merge branch 'for-3.18-consistent-ops' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu 2014-10-15 07:48:18 +02:00
microblaze Merge git://git.infradead.org/users/eparis/audit 2014-10-19 16:25:56 -07:00
mips MIPS: SEAD3: Fix I2C device registration. 2014-10-24 13:34:42 +02:00
mn10300 Merge branch 'locking-arch-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2014-10-13 15:48:00 +02:00
openrisc Merge git://git.infradead.org/users/eparis/audit 2014-10-19 16:25:56 -07:00
parisc Merge git://git.infradead.org/users/eparis/audit 2014-10-19 16:25:56 -07:00
powerpc Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linux 2014-10-21 07:48:56 -07:00
s390 s390/mm: prevent and break zero page mappings in case of storage keys 2014-10-27 13:27:25 +01:00
score score: use Kbuild logic to include <asm-generic/sections.h> 2014-10-09 22:25:46 -04:00
sh Merge git://git.infradead.org/users/eparis/audit 2014-10-19 16:25:56 -07:00
sparc Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc 2014-10-24 12:45:47 -07:00
tile Merge branch 'for-3.18-consistent-ops' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu 2014-10-15 07:48:18 +02:00
um Merge git://git.infradead.org/users/eparis/audit 2014-10-19 16:25:56 -07:00
unicore32 nosave: consolidate __nosave_{begin,end} in <asm/sections.h> 2014-10-09 22:26:04 -04:00
x86 This is a pretty large update. I think it is roughly as big 2014-10-24 12:42:55 -07:00
xtensa Merge git://git.infradead.org/users/eparis/audit 2014-10-19 16:25:56 -07:00
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