Re: [Qemu-devel] [PATCH v2] linux-user/main.c: Remove redundant end_exclusive() in arm_kernel_cmpxchg64_helper()

[Peter Maydell]

On 25 January 2015 at 11:03, Chen Gang S <address@hidden> wrote:
> start/end_exclusive() need be pairs, except the start_exclusive() in
> stop_all_tasks() which is only used by force_sig(), which will be abort.
> So at present, start_exclusive() in stop_all_task() need not be paired.
>
> queue_signal() may call force_sig(), or return after kill pid (or queue
> signal). If could return from queue_signal(), stop_all_task() would not
> be called in time, the next end_exclusive() would be issue.
>
> So in arm_kernel_cmpxchg64_helper() for ARM, need remove end_exclusive()
> after queue_signal(). The related commit: "97cc756 linux-user: Implement
> new ARM 64 bit cmpxchg kernel helper".
>
>
> Signed-off-by: Chen Gang <address@hidden>
> ---
>  linux-user/main.c | 2 --
>  1 file changed, 2 deletions(-)
>
> diff --git a/linux-user/main.c b/linux-user/main.c
> index 8c70be4..2d52c1f 100644
> --- a/linux-user/main.c
> +++ b/linux-user/main.c
> @@ -523,8 +523,6 @@ segv:
>      info.si_code = TARGET_SEGV_MAPERR;
>      info._sifields._sigfault._addr = env->exception.vaddress;
>      queue_signal(env, info.si_signo, &info);
> -
> -    end_exclusive();
>  }
>
>  /* Handle a jump to the kernel code page.  */

Reviewed-by: Peter Maydell <address@hidden>

thanks
-- PMM