diff options
authorPeter Maydell <peter.maydell@linaro.org>2019-02-21 18:17:45 +0000
committerPeter Maydell <peter.maydell@linaro.org>2019-02-21 18:17:45 +0000
commitcff21316c666c8053b1f425577e324038d0ca30d (patch)
parent763e10f7bb6413c745edf36e9e806c3d626c8262 (diff)
target/arm: v8M MPU should use background region as default, not always
The "background region" for a v8M MPU is a default which will be used (if enabled, and if the access is privileged) if the access does not match any specific MPU region. We were incorrectly using it always (by putting the condition at the wrong nesting level). This meant that we would always return the default background permissions rather than the correct permissions for a specific region, and also that we would not return the right information in response to a TT instruction. Move the check for the background region to the same place in the logic as the equivalent v8M MPUCheck() pseudocode puts it. This in turn means we must adjust the condition we use to detect matches in multiple regions to avoid false-positives. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Message-id: 20190214113408.10214-1-peter.maydell@linaro.org
1 files changed, 5 insertions, 3 deletions
diff --git a/target/arm/helper.c b/target/arm/helper.c
index a018eb23fe..fe054897c7 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -11387,9 +11387,11 @@ static bool pmsav8_mpu_lookup(CPUARMState *env, uint32_t address,
hit = true;
} else if (m_is_ppb_region(env, address)) {
hit = true;
- } else if (pmsav7_use_background_region(cpu, mmu_idx, is_user)) {
- hit = true;
} else {
+ if (pmsav7_use_background_region(cpu, mmu_idx, is_user)) {
+ hit = true;
+ }
for (n = (int)cpu->pmsav7_dregion - 1; n >= 0; n--) {
/* region search */
/* Note that the base address is bits [31:5] from the register
@@ -11427,7 +11429,7 @@ static bool pmsav8_mpu_lookup(CPUARMState *env, uint32_t address,
*is_subpage = true;
- if (hit) {
+ if (matchregion != -1) {
/* Multiple regions match -- always a failure (unlike
* PMSAv7 where highest-numbered-region wins)