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MIPS: uaccess: Add micromips clobbers to bzero invocation

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commit b3d7e55c3f886493235bfee08e1e5a4a27cbcce8 upstream.

The micromips implementation of bzero additionally clobbers registers t7
& t8. Specify this in the clobbers list when invoking bzero.

Fixes: 26c5e07d1478 ("MIPS: microMIPS: Optimise 'memset' core library function.")
Reported-by: James Hogan <jhogan@kernel.org>
Signed-off-by: Matt Redfearn <matt.redfearn@mips.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: <stable@vger.kernel.org> # 3.10+
Patchwork: https://patchwork.linux-mips.org/patch/19110/
Signed-off-by: James Hogan <jhogan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Matt Redfearn 2018-04-17 16:40:01 +01:00 committed by Greg Kroah-Hartman
parent d385cc6917
commit 1179774213
1 changed files with 9 additions and 2 deletions
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11
arch/mips/include/asm/uaccess.h
View File

@ -1257,6 +1257,13 @@ __clear_user(void __user *addr, __kernel_size_t size)
{
__kernel_size_t res;
#ifdef CONFIG_CPU_MICROMIPS
/* micromips memset / bzero also clobbers t7 & t8 */
#define bzero_clobbers "$4", "$5", "$6", __UA_t0, __UA_t1, "$15", "$24", "$31"
#else
#define bzero_clobbers "$4", "$5", "$6", __UA_t0, __UA_t1, "$31"
#endif /* CONFIG_CPU_MICROMIPS */
if (eva_kernel_access()) {
__asm__ __volatile__(
"move\t$4, %1\n\t"
@ -1266,7 +1273,7 @@ __clear_user(void __user *addr, __kernel_size_t size)
"move\t%0, $6"
: "=r" (res)
: "r" (addr), "r" (size)
: "$4", "$5", "$6", __UA_t0, __UA_t1, "$31");
: bzero_clobbers);
} else {
might_fault();
__asm__ __volatile__(
@ -1277,7 +1284,7 @@ __clear_user(void __user *addr, __kernel_size_t size)
"move\t%0, $6"
: "=r" (res)
: "r" (addr), "r" (size)
: "$4", "$5", "$6", __UA_t0, __UA_t1, "$31");
: bzero_clobbers);
}
return res;