diff options
| author | Will Deacon <will.deacon@arm.com> | 2010-11-19 13:18:31 +0100 |
|---|---|---|
| committer | Andi Kleen <ak@linux.intel.com> | 2010-12-14 23:40:15 +0100 |
| commit | a683346b0f0625d3b29194fa86082235d1e858ce (patch) | |
| tree | 3ebdcbfa8d6ac3180de94ce6f20c2727585cc4d4 | |
| parent | c088a5f8722f305b4bbaa94cad32f1bfa882bc71 (diff) | |
ARM: 6489/1: thumb2: fix incorrect optimisation in usracc
commit 1142b71d85894dcff1466dd6c871ea3c89e0352c upstream.
Commit 8b592783 added a Thumb-2 variant of usracc which, when it is
called with \rept=2, calls usraccoff once with an offset of 0 and
secondly with a hard-coded offset of 4 in order to avoid incrementing
the pointer again. If \inc != 4 then we will store the data to the wrong
offset from \ptr. Luckily, the only caller that passes \rept=2 to this
function is __clear_user so we haven't been actively corrupting user data.
This patch fixes usracc to pass \inc instead of #4 to usraccoff
when it is called a second time.
Reported-by: Tony Thompson <tony.thompson@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
| -rw-r--r-- | arch/arm/include/asm/assembler.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/arm/include/asm/assembler.h b/arch/arm/include/asm/assembler.h index 6e8f05c8a1c8..d7575554e407 100644 --- a/arch/arm/include/asm/assembler.h +++ b/arch/arm/include/asm/assembler.h @@ -215,7 +215,7 @@ @ Slightly optimised to avoid incrementing the pointer twice usraccoff \instr, \reg, \ptr, \inc, 0, \cond, \abort .if \rept == 2 - usraccoff \instr, \reg, \ptr, \inc, 4, \cond, \abort + usraccoff \instr, \reg, \ptr, \inc, \inc, \cond, \abort .endif add\cond \ptr, #\rept * \inc |