linux_dsm_epyc7002/arch
Dmitry Safonov 280e87e98c ARM: 8683/1: ARM32: Support mremap() for sigpage/vDSO
CRIU restores application mappings on the same place where they
were before Checkpoint. That means, that we need to move vDSO
and sigpage during restore on exactly the same place where
they were before C/R.

Make mremap() code update mm->context.{sigpage,vdso} pointers
during VMA move. Sigpage is used for landing after handling
a signal - if the pointer is not updated during moving, the
application might crash on any signal after mremap().

vDSO pointer on ARM32 is used only for setting auxv at this moment,
update it during mremap() in case of future usage.

Without those updates, current work of CRIU on ARM32 is not reliable.
Historically, we error Checkpointing if we find vDSO page on ARM32
and suggest user to disable CONFIG_VDSO.
But that's not correct - it goes from x86 where signal processing
is ended in vDSO blob. For arm32 it's sigpage, which is not disabled
with `CONFIG_VDSO=n'.

Looks like C/R was working by luck - because userspace on ARM32 at
this moment always sets SA_RESTORER.

Signed-off-by: Dmitry Safonov <dsafonov@virtuozzo.com>
Acked-by: Andy Lutomirski <luto@amacapital.net>
Cc: linux-arm-kernel@lists.infradead.org
Cc: Will Deacon <will.deacon@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Pavel Emelyanov <xemul@virtuozzo.com>
Cc: Christopher Covington <cov@codeaurora.org>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2017-06-21 13:02:58 +01:00
..
alpha Kbuild UAPI header export updates for v4.12 2017-05-10 20:45:36 -07:00
arc Kbuild UAPI header export updates for v4.12 2017-05-10 20:45:36 -07:00
arm ARM: 8683/1: ARM32: Support mremap() for sigpage/vDSO 2017-06-21 13:02:58 +01:00
arm64 arm64 2nd set of updates for 4.12: 2017-05-11 11:27:54 -07:00
blackfin uapi: export all headers under uapi directories 2017-05-11 00:21:54 +09:00
c6x uapi: export all headers under uapi directories 2017-05-11 00:21:54 +09:00
cris MTD updates for 4.12-rc1: 2017-05-11 10:44:22 -07:00
frv Kbuild UAPI header export updates for v4.12 2017-05-10 20:45:36 -07:00
h8300 uapi: export all headers under uapi directories 2017-05-11 00:21:54 +09:00
hexagon uapi: export all headers under uapi directories 2017-05-11 00:21:54 +09:00
ia64 Kbuild UAPI header export updates for v4.12 2017-05-10 20:45:36 -07:00
m32r uapi: export all headers under uapi directories 2017-05-11 00:21:54 +09:00
m68k uapi: export all headers under uapi directories 2017-05-11 00:21:54 +09:00
metag Kbuild UAPI header export updates for v4.12 2017-05-10 20:45:36 -07:00
microblaze uapi: export all headers under uapi directories 2017-05-11 00:21:54 +09:00
mips Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus 2017-05-12 09:56:30 -07:00
mn10300 uapi: export all headers under uapi directories 2017-05-11 00:21:54 +09:00
nios2 nios2 update for v4.12-rc1 2017-05-12 09:53:16 -07:00
openrisc uapi: export all headers under uapi directories 2017-05-11 00:21:54 +09:00
parisc uapi: export all headers under uapi directories 2017-05-11 00:21:54 +09:00
powerpc powerpc updates for 4.12 part 2 2017-05-12 10:04:09 -07:00
s390 uapi: export all headers under uapi directories 2017-05-11 00:21:54 +09:00
score uapi: export all headers under uapi directories 2017-05-11 00:21:54 +09:00
sh Kbuild UAPI header export updates for v4.12 2017-05-10 20:45:36 -07:00
sparc Kbuild UAPI header export updates for v4.12 2017-05-10 20:45:36 -07:00
tile arch/include: remove empty Kbuild files 2017-05-11 00:22:18 +09:00
um Merge branch 'for-linus-4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml 2017-05-13 10:20:02 -07:00
unicore32 Kbuild UAPI header export updates for v4.12 2017-05-10 20:45:36 -07:00
x86 ARM: 8683/1: ARM32: Support mremap() for sigpage/vDSO 2017-06-21 13:02:58 +01:00
xtensa uapi: export all headers under uapi directories 2017-05-11 00:21:54 +09:00
.gitignore
Kconfig Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-05-10 10:30:46 -07:00