Re: [PATCH v3 1/2] target/i386: fix hang when using slow path for ptw_setl

[Richard Henderson <richard.henderson@linaro.org>]

On 10/25/24 18:58, Pierrick Bouvier wrote:
> When instrumenting memory accesses for plugin, we force memory accesses
> to use the slow path for mmu [1]. This create a situation where we end
> up calling ptw_setl_slow. This was fixed recently in [2] but the issue
> still could appear out of plugins use case.
> 
> Since this function gets called during a cpu_exec, start_exclusive then
> hangs. This exclusive section was introduced initially for security
> reasons [3].
> 
> I suspect this code path was never triggered, because ptw_setl_slow
> would always be called transitively from cpu_exec, resulting in a hang.
> 
> [1]https://gitlab.com/qemu-project/qemu/-/commit/6d03226b42247b68ab2f0b3663e0f624335a4055
> [2]https://gitlab.com/qemu-project/qemu/-/commit/115ade42d50144c15b74368d32dc734ea277d853
> [3]https://gitlab.com/qemu-project/qemu/-/issues/279
> 
> Fixes:https://gitlab.com/qemu-project/qemu/-/issues/2566
> Signed-off-by: Pierrick Bouvier<pierrick.bouvier@linaro.org>
> ---
>   target/i386/tcg/sysemu/excp_helper.c | 5 +++++
>   1 file changed, 5 insertions(+)

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

r~