If page in 'ptr_access' is inaccessible and probe is 'true'
allocation_tag_mem_probe should not throw an exception, but currently it
does, so fix it.

Signed-off-by: Gustavo Romero <gustavo.romero@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
---
 target/arm/tcg/mte_helper.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/target/arm/tcg/mte_helper.c b/target/arm/tcg/mte_helper.c
index 037ac6dd60..a50d576294 100644
--- a/target/arm/tcg/mte_helper.c
+++ b/target/arm/tcg/mte_helper.c
@@ -96,6 +96,9 @@ static uint8_t *allocation_tag_mem_probe(CPUARMState *env, int ptr_mmu_idx,
     assert(!(probe && ra));
 
     if (!(flags & (ptr_access == MMU_DATA_STORE ? PAGE_WRITE_ORG : PAGE_READ))) {
+        if (probe) {
+            return NULL;
+        }
         cpu_loop_exit_sigsegv(env_cpu(env), ptr, ptr_access,
                               !(flags & PAGE_VALID), ra);
     }
-- 
2.34.1