Re: [Qemu-devel] [PATCH 1/1] Fix do_rt_sigreturn on m68k linux userspace emulation

[Laurent Vivier]

Le 09/12/2015 21:54, Michael Karcher a écrit :
> do_rt_sigreturn forgets to initialize the signal mask variable before
> trying to use it to restore the mask, so the signal mask is undefined
> after do_rt_sigreturn. This bug has been in all the time since
> 7181155d when do_rt_sigreturn was implemented for m68k.
> 
> Signed-off-by: Michael Karcher <address@hidden>
> ---
>  linux-user/signal.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/linux-user/signal.c b/linux-user/signal.c
> index e03ed60..ae1014b 100644
> --- a/linux-user/signal.c
> +++ b/linux-user/signal.c
> @@ -5260,11 +5260,14 @@ long do_rt_sigreturn(CPUM68KState *env)
>      abi_ulong frame_addr = env->aregs[7] - 4;
>      target_sigset_t target_set;
>      sigset_t set;
> -    int d0;
> +    int d0, i;
>  
>      if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1))
>          goto badframe;
>  
> +    for(i = 0; i < TARGET_NSIG_WORDS; i++) {
> +        target_set.sig[i] = frame->uc.tuc_sigmask.sig[i];
> +    }
>      target_to_host_sigset_internal(&set, &target_set);
>      do_sigprocmask(SIG_SETMASK, &set, NULL);
>  
> 

Nice catch.

I agree with you that the current code is completely  broken, but on the
other architectures, this operation seems to be done directly by

target_to_host_sigset(&set, &frame->uc.tuc_sigmask);

Could you have try with that ?

Thank you for your help,
Laurent