ARM: 6489/1: thumb2: fix incorrect optimisation in usracc
commitbcaefff16de46a7ca217e71f95de384786ebb4d5
authorWill Deacon <will.deacon@arm.com>
Fri, 19 Nov 2010 12:18:31 +0000 (19 13:18 +0100)
committerGreg Kroah-Hartman <gregkh@suse.de>
Mon, 21 Mar 2011 19:44:09 +0000 (21 12:44 -0700)
treec38afdbc532a48dcc174dff7befd4415843f3760
parent3a27414883e624fdfc62b747a19f106448fb62ca
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>
arch/arm/include/asm/assembler.h