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[v2,02/10] target/arm: Correct value returned by pmu_counter_mask()

Message ID 20220822132358.3524971-3-peter.maydell@linaro.org
State Superseded
Headers show
Series target/arm: Implement FEAT_PMUv3p5 | expand

Commit Message

Peter Maydell Aug. 22, 2022, 1:23 p.m. UTC 
pmu_counter_mask() accidentally returns a value with bits [63:32]
set, because the expression it returns is evaluated as a signed value
that gets sign-extended to 64 bits.  Force the whole expression to be
evaluated with 64-bit arithmetic with ULL suffixes.

The main effect of this bug was that a guest could write to the bits
in the high half of registers like PMCNTENSET_EL0 that are supposed
to be RES0.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
---
 target/arm/internals.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
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Patch

diff --git a/target/arm/internals.h b/target/arm/internals.h
index b8fefdff675..83526166de0 100644
--- a/target/arm/internals.h
+++ b/target/arm/internals.h
@@ -1296,7 +1296,7 @@  static inline uint32_t pmu_num_counters(CPUARMState *env)
 /* Bits allowed to be set/cleared for PMCNTEN* and PMINTEN* */
 static inline uint64_t pmu_counter_mask(CPUARMState *env)
 {
-  return (1 << 31) | ((1 << pmu_num_counters(env)) - 1);
+  return (1ULL << 31) | ((1ULL << pmu_num_counters(env)) - 1);
 }
 
 #ifdef TARGET_AARCH64