linux-stable/arch/arm64/kernel/vdso
Will Deacon f84a935db4 arm64: vdso: check sequence counter even for coarse realtime operations
When returning coarse realtime values from clock_gettime, we must still
check the sequence counter to ensure that the kernel does not update
the vdso datapage whilst we are loading the coarse timespec as this
could potentially result in time appearing to go backwards.

This patch delays the coarse realtime check until after we have loaded
successfully from the vdso datapage. This does mean that we always load
the wtm timespec, but conditionalising the load and adding an extra
sequence test is unlikely to buy us anything other than messy code,
particularly as the sequence test implies a read barrier.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2012-12-05 11:20:03 +00:00
..
.gitignore arm64: VDSO support 2012-09-17 13:42:09 +01:00
gen_vdso_offsets.sh arm64: VDSO support 2012-09-17 13:42:09 +01:00
gettimeofday.S arm64: vdso: check sequence counter even for coarse realtime operations 2012-12-05 11:20:03 +00:00
Makefile arm64: VDSO support 2012-09-17 13:42:09 +01:00
note.S arm64: VDSO support 2012-09-17 13:42:09 +01:00
sigreturn.S arm64: VDSO support 2012-09-17 13:42:09 +01:00
vdso.lds.S arm64: VDSO support 2012-09-17 13:42:09 +01:00
vdso.S arm64: VDSO support 2012-09-17 13:42:09 +01:00