Re: linux-next: umh: fix processed error when UMH_WAIT_PROC is used seems to break linux bridge on s390x (bisected)
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From: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Date: 2020-07-02 04:28:31
Also in:
bridge, keyrings, linux-fsdevel, linux-nfs, linux-s390, lkml, netdev
On 2020/07/02 0:38, Luis Chamberlain wrote:
quoted hunk ↗ jump to hunk
@@ -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".
quoted hunk ↗ jump to hunk
+ /* 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 */