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authorPeter Maydell <peter.maydell@linaro.org>2017-10-06 16:46:48 +0100
committerPeter Maydell <peter.maydell@linaro.org>2017-10-06 16:46:48 +0100
commitcb484f9a6e790205e69d9a444c3e353a3a1cfd84 (patch)
tree67e923445764a853f879010e2631a77fdff6819f /target
parent224e0c300a0098fb577a03bd29d774d0769f632a (diff)
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target/arm: Warn about restoring to unaligned stack
Attempting to do an exception return with an exception frame that is not 8-aligned is UNPREDICTABLE in v8M; warn about this. (It is not UNPREDICTABLE in v7M, and our implementation can handle the merely-4-aligned case fine, so we don't need to do anything except warn.) Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Message-id: 1506092407-26985-8-git-send-email-peter.maydell@linaro.org
Diffstat (limited to 'target')
-rw-r--r--target/arm/helper.c7
1 files changed, 7 insertions, 0 deletions
diff --git a/target/arm/helper.c b/target/arm/helper.c
index bee0f5d..bb57be7 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -6413,6 +6413,13 @@ static void do_v7m_exception_exit(ARMCPU *cpu)
return_to_sp_process);
uint32_t frameptr = *frame_sp_p;
+ if (!QEMU_IS_ALIGNED(frameptr, 8) &&
+ arm_feature(env, ARM_FEATURE_V8)) {
+ qemu_log_mask(LOG_GUEST_ERROR,
+ "M profile exception return with non-8-aligned SP "
+ "for destination state is UNPREDICTABLE\n");
+ }
+
/* Pop registers. TODO: make these accesses use the correct
* attributes and address space (S/NS, priv/unpriv) and handle
* memory transaction failures.