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authorPeter Maydell <peter.maydell@linaro.org>2017-07-27 11:59:07 +0100
committerPeter Maydell <peter.maydell@linaro.org>2017-07-31 13:09:18 +0100
commitbf446a11dfb17ae7d8ed2b61a2444804eb458075 (patch)
tree0e322d33916bccce25d8869294e5fbfd914f84b6
parent38aaa60ca464b48e6feef346709e97335d01b289 (diff)
target/arm: Don't allow guest to make System space executable for M profile
For an M profile v7PMSA, the system space (0xe0000000 - 0xffffffff) can never be executable, even if the guest tries to set the MPU registers up that way. Enforce this restriction. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Message-id: 1501153150-19984-3-git-send-email-peter.maydell@linaro.org
-rw-r--r--target/arm/helper.c16
1 files changed, 15 insertions, 1 deletions
diff --git a/target/arm/helper.c b/target/arm/helper.c
index 3d6057503d..f0299c5282 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -8251,6 +8251,14 @@ static inline bool m_is_ppb_region(CPUARMState *env, uint32_t address)
extract32(address, 20, 12) == 0xe00;
}
+static inline bool m_is_system_region(CPUARMState *env, uint32_t address)
+{
+ /* True if address is in the M profile system region
+ * 0xe0000000 - 0xffffffff
+ */
+ return arm_feature(env, ARM_FEATURE_M) && extract32(address, 29, 3) == 0x7;
+}
+
static bool get_phys_addr_pmsav7(CPUARMState *env, uint32_t address,
int access_type, ARMMMUIdx mmu_idx,
hwaddr *phys_ptr, int *prot, uint32_t *fsr)
@@ -8354,6 +8362,12 @@ static bool get_phys_addr_pmsav7(CPUARMState *env, uint32_t address,
get_phys_addr_pmsav7_default(env, mmu_idx, address, prot);
} else { /* a MPU hit! */
uint32_t ap = extract32(env->pmsav7.dracr[n], 8, 3);
+ uint32_t xn = extract32(env->pmsav7.dracr[n], 12, 1);
+
+ if (m_is_system_region(env, address)) {
+ /* System space is always execute never */
+ xn = 1;
+ }
if (is_user) { /* User mode AP bit decoding */
switch (ap) {
@@ -8394,7 +8408,7 @@ static bool get_phys_addr_pmsav7(CPUARMState *env, uint32_t address,
}
/* execute never */
- if (env->pmsav7.dracr[n] & (1 << 12)) {
+ if (xn) {
*prot &= ~PAGE_EXEC;
}
}