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authorPeter Maydell <peter.maydell@linaro.org>2016-02-23 15:36:43 +0000
committerPeter Maydell <peter.maydell@linaro.org>2016-02-26 15:09:41 +0000
commitcb01d3912c8b000ed26d5fe95f6c194b3e3ba7a6 (patch)
tree1482249d7b141245cf2048e98770414ad37b43da
parentae08792301c182bdec48656dee3dce38b3391a1a (diff)
target-arm: In cpsr_write() ignore mode switches from User mode
The only case where we can attempt a cpsr_write() mode switch from User is from the gdbstub; all other cases are handled in the calling code (notably translate.c). Architecturally attempts to alter the mode bits from user mode are simply ignored (and not treated as a bad mode switch, which in v8 sets CPSR.IL). Make mode switches from User ignored in cpsr_write() as well, for consistency. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Sergey Fedorov <serge.fdrv@gmail.com> Message-id: 1455556977-3644-6-git-send-email-peter.maydell@linaro.org
-rw-r--r--target-arm/helper.c1
1 files changed, 1 insertions, 0 deletions
diff --git a/target-arm/helper.c b/target-arm/helper.c
index c491cd80ab..b2d2440edd 100644
--- a/target-arm/helper.c
+++ b/target-arm/helper.c
@@ -5316,6 +5316,7 @@ void cpsr_write(CPUARMState *env, uint32_t val, uint32_t mask,
env->daif |= val & CPSR_AIF & mask;
if (write_type != CPSRWriteRaw &&
+ (env->uncached_cpsr & CPSR_M) != CPSR_USER &&
((env->uncached_cpsr ^ val) & mask & CPSR_M)) {
if (bad_mode_switch(env, val & CPSR_M)) {
/* Attempt to switch to an invalid mode: this is UNPREDICTABLE.