| Message ID | 1455556977-3644-6-git-send-email-peter.maydell@linaro.org |
|---|---|
| State | New |
| Headers | show |
On 15.02.2016 20:22, Peter Maydell wrote: > 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> > --- > target-arm/helper.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/target-arm/helper.c b/target-arm/helper.c > index d1919bb..9998a25 100644 > --- a/target-arm/helper.c > +++ b/target-arm/helper.c > @@ -5282,6 +5282,7 @@ 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.
diff --git a/target-arm/helper.c b/target-arm/helper.c index d1919bb..9998a25 100644 --- a/target-arm/helper.c +++ b/target-arm/helper.c @@ -5282,6 +5282,7 @@ 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.
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> --- target-arm/helper.c | 1 + 1 file changed, 1 insertion(+)