| Message ID | 1506092407-26985-8-git-send-email-peter.maydell@linaro.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series | ARM v8M: exception entry, exit and security | expand |
On 09/22/2017 11:59 AM, Peter Maydell wrote: > 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> > --- > target/arm/helper.c | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/target/arm/helper.c b/target/arm/helper.c > index a2e46fb..979129e 100644 > --- a/target/arm/helper.c > +++ b/target/arm/helper.c > @@ -6403,6 +6403,13 @@ 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. >
On 09/22/2017 10:59 AM, Peter Maydell wrote: > 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> > --- > target/arm/helper.c | 7 +++++++ > 1 file changed, 7 insertions(+) Reviewed-by: Richard Henderson <richard.henderson@linaro.org> r~
diff --git a/target/arm/helper.c b/target/arm/helper.c index a2e46fb..979129e 100644 --- a/target/arm/helper.c +++ b/target/arm/helper.c @@ -6403,6 +6403,13 @@ 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.
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> --- target/arm/helper.c | 7 +++++++ 1 file changed, 7 insertions(+) -- 2.7.4