[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Qemu-devel] [PATCH 8/8] target-arm: ignore ELR_ELx[1] for exception ret
From: |
Peter Maydell |
Subject: |
[Qemu-devel] [PATCH 8/8] target-arm: ignore ELR_ELx[1] for exception return to 32-bit ARM mode |
Date: |
Thu, 14 Jan 2016 18:34:11 +0000 |
The architecture requires that for an exception return to AArch32 the
low bits of ELR_ELx are ignored when the PC is set from them:
* if returning to Thumb mode, ignore ELR_ELx[0]
* if returning to ARM mode, ignore ELR_ELx[1:0]
We were only squashing bit 0; also squash bit 1 if the SPSR T bit
indicates this is a return to ARM code.
Signed-off-by: Peter Maydell <address@hidden>
---
target-arm/op_helper.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/target-arm/op_helper.c b/target-arm/op_helper.c
index 5789ccb..171d6b8 100644
--- a/target-arm/op_helper.c
+++ b/target-arm/op_helper.c
@@ -738,7 +738,11 @@ void HELPER(exception_return)(CPUARMState *env)
}
aarch64_sync_64_to_32(env);
- env->regs[15] = env->elr_el[cur_el] & ~0x1;
+ if (spsr & CPSR_T) {
+ env->regs[15] = env->elr_el[cur_el] & ~0x1;
+ } else {
+ env->regs[15] = env->elr_el[cur_el] & ~0x3;
+ }
} else {
env->aarch64 = 1;
pstate_write(env, spsr);
--
1.9.1
- Re: [Qemu-devel] [PATCH 1/8] target-arm: Properly support EL2 and EL3 in arm_el_is_aa64(), (continued)
Re: [Qemu-devel] [PATCH 1/8] target-arm: Properly support EL2 and EL3 in arm_el_is_aa64(), Sergey Fedorov, 2016/01/29
[Qemu-devel] [PATCH 4/8] target-arm: Pull semihosting handling out to arm_cpu_do_interrupt(), Peter Maydell, 2016/01/14
[Qemu-devel] [PATCH 8/8] target-arm: ignore ELR_ELx[1] for exception return to 32-bit ARM mode,
Peter Maydell <=
[Qemu-devel] [PATCH 2/8] target-arm: Move aarch64_cpu_do_interrupt() to helper.c, Peter Maydell, 2016/01/14
[Qemu-devel] [PATCH 6/8] target-arm: Handle exception return from AArch64 to non-EL0 AArch32, Peter Maydell, 2016/01/14
[Qemu-devel] [PATCH 5/8] target-arm: Fix wrong AArch64 entry offset for EL2/EL3 target, Peter Maydell, 2016/01/14