Messages in this thread | | | Subject | Re: linux-next: umh: fix processed error when UMH_WAIT_PROC is used seems to break linux bridge on s390x (bisected) | From | Tetsuo Handa <> | Date | Thu, 2 Jul 2020 13:26:53 +0900 |
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On 2020/07/02 0:38, Luis Chamberlain wrote: > @@ -156,6 +156,18 @@ static void call_usermodehelper_exec_sync(struct subprocess_info *sub_info) > */ > if (KWIFEXITED(ret)) > sub_info->retval = KWEXITSTATUS(ret); > + /* > + * Do we really want to be passing the signal, or do we pass > + * a single error code for all cases? > + */ > + else if (KWIFSIGNALED(ret)) > + sub_info->retval = KWTERMSIG(ret);
No, this is bad. Caller of usermode helper is unable to distinguish exit(9) and e.g. SIGKILL'ed by the OOM-killer. Please pass raw exit status value.
I feel that caller of usermode helper should not use exit status value. For example, call_sbin_request_key() is checking
test_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags) || key_validate(key) < 0
condition (if usermode helper was invoked) in order to "ignore any errors from userspace if the key was instantiated".
> + /* Same here */ > + else if (KWIFSTOPPED((ret))) > + sub_info->retval = KWSTOPSIG(ret); > + /* And are we really sure we want this? */ > + else if (KWIFCONTINUED((ret))) > + sub_info->retval = 0; > } > > /* Restore default kernel sig handler */ >
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