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authorMatt Redfearn <matt.redfearn@mips.com>2018-04-17 18:40:01 +0300
committerJames Hogan <jhogan@kernel.org>2018-04-19 00:02:29 +0300
commitb3d7e55c3f886493235bfee08e1e5a4a27cbcce8 (patch)
tree5de7a8125f8693278ef93b15ea9e45dbdfce6507
parentc96eebf07692e53bf4dd5987510d8b550e793598 (diff)
downloadlinux-b3d7e55c3f886493235bfee08e1e5a4a27cbcce8.tar.xz
MIPS: uaccess: Add micromips clobbers to bzero invocation
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>
-rw-r--r--arch/mips/include/asm/uaccess.h11
1 files changed, 9 insertions, 2 deletions
diff --git a/arch/mips/include/asm/uaccess.h b/arch/mips/include/asm/uaccess.h
index b71306947290..06629011a434 100644
--- a/arch/mips/include/asm/uaccess.h
+++ b/arch/mips/include/asm/uaccess.h
@@ -654,6 +654,13 @@ __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"
@@ -663,7 +670,7 @@ __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__(
@@ -674,7 +681,7 @@ __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;