Re: [Qemu-devel] [PATCH 1/3] target/arm: fix crash on pmu register access
On Mar 22 17:23, Andrew Jones wrote: > Fix a QEMU NULL derefence that occurs when the guest attempts to > enable PMU counters with a non-v8 cpu model or a v8 cpu model > which has not configured a PMU. > > Fixes: 4e7beb0cc0f3 ("target/arm: Add a timer to predict PMU counter > overflow") > Signed-off-by: Andrew Jones Reviewed-by: Aaron Lindsay > --- > target/arm/helper.c | 4 > 1 file changed, 4 insertions(+) > > diff --git a/target/arm/helper.c b/target/arm/helper.c > index c8d3c213b6b7..fc73488f6cc0 100644 > --- a/target/arm/helper.c > +++ b/target/arm/helper.c > @@ -1259,6 +1259,10 @@ static bool pmu_counter_enabled(CPUARMState *env, > uint8_t counter) > int el = arm_current_el(env); > uint8_t hpmn = env->cp15.mdcr_el2 & MDCR_HPMN; > > +if (!arm_feature(env, ARM_FEATURE_PMU)) { > +return false; > +} > + > if (!arm_feature(env, ARM_FEATURE_EL2) || > (counter < hpmn || counter == 31)) { > e = env->cp15.c9_pmcr & PMCRE; > -- > 2.17.2 >
[Qemu-devel] [PATCH 1/3] target/arm: fix crash on pmu register access
Fix a QEMU NULL derefence that occurs when the guest attempts to enable PMU counters with a non-v8 cpu model or a v8 cpu model which has not configured a PMU. Fixes: 4e7beb0cc0f3 ("target/arm: Add a timer to predict PMU counter overflow") Signed-off-by: Andrew Jones --- target/arm/helper.c | 4 1 file changed, 4 insertions(+) diff --git a/target/arm/helper.c b/target/arm/helper.c index c8d3c213b6b7..fc73488f6cc0 100644 --- a/target/arm/helper.c +++ b/target/arm/helper.c @@ -1259,6 +1259,10 @@ static bool pmu_counter_enabled(CPUARMState *env, uint8_t counter) int el = arm_current_el(env); uint8_t hpmn = env->cp15.mdcr_el2 & MDCR_HPMN; +if (!arm_feature(env, ARM_FEATURE_PMU)) { +return false; +} + if (!arm_feature(env, ARM_FEATURE_EL2) || (counter < hpmn || counter == 31)) { e = env->cp15.c9_pmcr & PMCRE; -- 2.17.2