@@ -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;
The micromips implementation of bzero additionally clobbers registers t7 & t8. Specify this in the clobbers list when invoking bzero. Reported-by: James Hogan <> Fixes: 26c5e07d1478 ("MIPS: microMIPS: Optimise 'memset' core library function.") Cc: Signed-off-by: Matt Redfearn <> --- Changes in v2: None arch/mips/include/asm/uaccess.h | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-)