From cb484f9a6e790205e69d9a444c3e353a3a1cfd84 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Fri, 6 Oct 2017 16:46:48 +0100 Subject: target/arm: Warn about restoring to unaligned stack MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Reviewed-by: Philippe Mathieu-Daudé Reviewed-by: Richard Henderson Message-id: 1506092407-26985-8-git-send-email-peter.maydell@linaro.org --- target/arm/helper.c | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'target') diff --git a/target/arm/helper.c b/target/arm/helper.c index bee0f5ddb6..bb57be73bf 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. -- cgit v1.2.1