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 */ >
