Latest stable (r287104) bash leaves zombies on exit

[Jilles Tjoelker]

On Sat, Aug 29, 2015 at 04:41:30PM +0300, Konstantin Belousov wrote:
> On Sat, Aug 29, 2015 at 03:01:38PM +0200, Jilles Tjoelker wrote:
> > Looks good to me, except that I think a vforked child (in system() and
> > posix_spawn*()) should use the system calls and not libthr's wrappers.
> > This reduces the probability of weird things happening between vfork and
> > exec, and also avoids an unexpected error when
> > posix_spawnattr_setsigdefault()'s mask contains SIGTHR.

> Thank you for the review, I agree with the note about vfork. Updated
> patch is below. Also, I removed the PIC_PROLOGUE from the i386 setjmp,
> it has no use after the plt calls are removed.

> [snip]
> diff --git a/lib/libc/gen/posix_spawn.c b/lib/libc/gen/posix_spawn.c
> index e3124b2..673c760 100644
> --- a/lib/libc/gen/posix_spawn.c
> +++ b/lib/libc/gen/posix_spawn.c
> @@ -118,15 +118,18 @@ process_spawnattr(const posix_spawnattr_t sa)
>  			return (errno);
>  	}
>  
> -	/* Set signal masks/defaults */
> +	/*
> +	 * Set signal masks/defaults.
> +	 * Use unwrapped syscall, libthr is in undefined state after vfork().
> +	 */
>  	if (sa->sa_flags & POSIX_SPAWN_SETSIGMASK) {
> -		_sigprocmask(SIG_SETMASK, &sa->sa_sigmask, NULL);
> +		__libc_sigprocmask(SIG_SETMASK, &sa->sa_sigmask, NULL);
>  	}
>  
>  	if (sa->sa_flags & POSIX_SPAWN_SETSIGDEF) {
>  		for (i = 1; i <= _SIG_MAXSIG; i++) {
>  			if (sigismember(&sa->sa_sigdefault, i))
> -				if (_sigaction(i, &sigact, NULL) != 0)
> +				if (__libc_sigaction(i, &sigact, NULL) != 0)
>  					return (errno);
>  		}
>  	}

Hmm, the comments say direct syscalls are being used, but in fact
libthr's interposer is called. The change to system() does correctly use
__sys_sigprocmask().

-- 
Jilles Tjoelker