@@ -54,7 +54,7 @@ static inline bool arch_collect_entropy(uint64_t *random)
"stp q26, q27, [%0], #32\n\t" \
"stp q28, q29, [%0], #32\n\t" \
"stp q30, q31, [%0], #32\n\t" \
- : "=r" (__val) \
+ : "+r" (__val) \
: \
: "v0", "v1", "v2", "v3", \
"v4", "v5", "v6", "v7", \
@@ -87,8 +87,8 @@ do { \
"ldp q26, q27, [%0], #32\n\t" \
"ldp q28, q29, [%0], #32\n\t" \
"ldp q30, q31, [%0], #32\n\t" \
+ : "+r" (__val) \
: \
- : "r" (__val) \
: "v0", "v1", "v2", "v3", \
"v4", "v5", "v6", "v7", \
"v8", "v9", "v10", "v11", \
@@ -138,8 +138,8 @@ do { \
"str z29, [%0, #29, MUL VL]\n" \
"str z30, [%0, #30, MUL VL]\n" \
"str z31, [%0, #31, MUL VL]\n" \
- : "=r" (__val) \
: \
+ : "r" (__val) \
: "z0", "z1", "z2", "z3", \
"z4", "z5", "z6", "z7", \
"z8", "z9", "z10", "z11", \
The macros fpu_reg_{read,write} post-increment the '__val' pointer register as a part of 'stp' and 'ldp' instructions. As a result, mark it with "+r" for the compiler to treat it as read-write operand. On the contrary, sve_reg_read() never updates the value of the pointer/register. Hence, mark this as "r" for the compiler to treat it as read-only operand. Without these adjustments, the compiler can potentially perform optimizations over the registers holding the pointers that could lead to data aborts. Fixes: d47d370c8f ("arm: Add test for FPU/SIMD context save/restore") Signed-off-by: Raghavendra Rao Ananta <rananta@google.com> --- arm/fpu.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)