Re: [PATCH for-6.1 2/6] target/arm: Add missing 'return's after calling v7m_exception_taken()

[Richard Henderson]

On 7/23/21 6:21 AM, Peter Maydell wrote:
> In do_v7m_exception_exit(), we perform various checks as part of
> performing the exception return.  If one of these checks fails, the
> architecture requires that we take an appropriate exception on the
> existing stackframe.  We implement this by calling
> v7m_exception_taken() to set up to take the new exception, and then
> immediately returning from do_v7m_exception_exit() without proceeding
> any further with the unstack-and-exception-return process.
>
> In a couple of checks that are new in v8.1M, we forgot the "return"
> statement, with the effect that if bad code in the guest tripped over
> these checks we would set up to take a UsageFault exception but then
> blunder on trying to also unstack and return from the original
> exception, with the probable result that the guest would crash.
>
> Add the missing return statements.
>
> Signed-off-by: Peter Maydell<peter.maydell@linaro.org>
> ---
>   target/arm/m_helper.c | 2 ++
>   1 file changed, 2 insertions(+)

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

r~