diff options
| author | Richard Henderson <richard.henderson@linaro.org> | 2021-11-03 00:03:49 -0400 |
|---|---|---|
| committer | Peter Maydell <peter.maydell@linaro.org> | 2021-12-15 10:35:26 +0000 |
| commit | ee03027a2cef00f977a3d28242c0a250b8552495 (patch) | |
| tree | 42e74225bdb97be6a66025ec7a5b6eb519ef34ba /target/arm/syndrome.h | |
| parent | 936a6b86030a0db172b09a1ea953091a1555611e (diff) | |
target/arm: Take an exception if PC is misaligned
For A64, any input to an indirect branch can cause this.
For A32, many indirect branch paths force the branch to be aligned,
but BXWritePC does not. This includes the BX instruction but also
other interworking changes to PC. Prior to v8, this case is UNDEFINED.
With v8, this is CONSTRAINED UNPREDICTABLE and may either raise an
exception or force align the PC.
We choose to raise an exception because we have the infrastructure,
it makes the generated code for gen_bx simpler, and it has the
possibility of catching more guest bugs.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Diffstat (limited to 'target/arm/syndrome.h')
| -rw-r--r-- | target/arm/syndrome.h | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/target/arm/syndrome.h b/target/arm/syndrome.h index f30f4130a2..8cde8e7243 100644 --- a/target/arm/syndrome.h +++ b/target/arm/syndrome.h @@ -282,4 +282,9 @@ static inline uint32_t syn_illegalstate(void) return (EC_ILLEGALSTATE << ARM_EL_EC_SHIFT) | ARM_EL_IL; } +static inline uint32_t syn_pcalignment(void) +{ + return (EC_PCALIGNMENT << ARM_EL_EC_SHIFT) | ARM_EL_IL; +} + #endif /* TARGET_ARM_SYNDROME_H */ |