[CRIU] [PATCH] pie: print an error and notify criu in error cases

[Tycho Andersen]

On Tue, Feb 09, 2016 at 12:47:51AM +0300, Andrey Vagin wrote:
> From: Andrew Vagin <avagin at virtuozzo.com>
> 
> Cc: Tycho Andersen <tycho.andersen at canonical.com>

Ah, yes. The reason we couldn't do something like this before is
because it happened after the log file was closed and the last stage
was finished. Anyway, thanks:

Acked-by: Tycho Andersen <tycho.andersen at canonical.com>

> Signed-off-by: Andrew Vagin <avagin at virtuozzo.com>
> ---
>  pie/restorer.c | 33 ++++++++++++++++++---------------
>  1 file changed, 18 insertions(+), 15 deletions(-)
> 
> diff --git a/pie/restorer.c b/pie/restorer.c
> index d99c92d..8cec7f9 100644
> --- a/pie/restorer.c
> +++ b/pie/restorer.c
> @@ -344,15 +344,20 @@ static int restore_signals(siginfo_t *ptr, int nr, bool group)
>  	return 0;
>  }
>  
> -static void restore_seccomp(struct task_restore_args *args)
> +static int restore_seccomp(struct task_restore_args *args)
>  {
> +	int ret;
> +
>  	switch (args->seccomp_mode) {
>  	case SECCOMP_MODE_DISABLED:
> -		return;
> +		return 0;
>  	case SECCOMP_MODE_STRICT:
> -		if (sys_prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, 0, 0, 0))
> +		ret = sys_prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, 0, 0, 0);
> +		if (ret < 0) {
> +			pr_err("prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT) returned %d\n", ret);
>  			goto die;
> -		return;
> +		}
> +		return 0;
>  	case SECCOMP_MODE_FILTER: {
>  		int i;
>  		void *filter_data;
> @@ -369,27 +374,24 @@ static void restore_seccomp(struct task_restore_args *args)
>  			 * don't have to restore_seccomp() in threads, and that
>  			 * future TSYNC behavior will be correct.
>  			 */
> -			if (sys_seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC, (char *) fprog) < 0)
> +			ret = sys_seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC, (char *) fprog);
> +			if (ret < 0) {
> +				pr_err("sys_seccomp() returned %d\n", ret);
>  				goto die;
> +			}
>  
>  			filter_data += fprog->len * sizeof(struct sock_filter);
>  		}
>  
> -		return;
> +		return 0;
>  	}
>  	default:
>  		goto die;
>  	}
>  
> +	return 0;
>  die:
> -	/*
> -	 * If preparing any seccomp state failed, we should make sure this
> -	 * process doesn't continue so that it can't do things outside the
> -	 * sandbox. Unfortunately, the rest of the restore has to continue
> -	 * since we're too late in the process to stop it and have unlocked the
> -	 * network.
> -	 */
> -	sys_exit_group(1);
> +	return -1;
>  }
>  
>  static int restore_thread_common(struct rt_sigframe *sigframe,
> @@ -1268,7 +1270,8 @@ long __export_restore_task(struct task_restore_args *args)
>  	 * ns, so we must do this before restore_creds.
>  	 */
>  	pr_info("restoring seccomp mode %d for %ld\n", args->seccomp_mode, sys_getpid());
> -	restore_seccomp(args);
> +	if (restore_seccomp(args))
> +		goto core_restore_end;
>  
>  	/*
>  	 * Writing to last-pid is CAP_SYS_ADMIN protected,
> -- 
> 2.4.3
>