From: Will Deacon Date: Fri, 19 Nov 2010 12:18:31 +0000 (+0100) Subject: ARM: 6489/1: thumb2: fix incorrect optimisation in usracc X-Git-Tag: v2.6.35.10~41 X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=a683346b0f0625d3b29194fa86082235d1e858ce;p=karo-tx-linux.git 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 Acked-by: Catalin Marinas Signed-off-by: Will Deacon Signed-off-by: Russell King Signed-off-by: Greg Kroah-Hartman Signed-off-by: Andi Kleen --- 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