[PATCH 3/3] module: Properly propagate MODULE_STATE_COMING failure

From: Peter Zijlstra <peterz@infradead.org>
To: Jessica Yu <jeyu@kernel.org>,
	linux-kernel@vger.kernel.org, jpoimboe@redhat.com,
	jikos@kernel.org, mbenes@suse.cz, pmladek@suse.com,
	ast@kernel.org, daniel@iogearbox.net, akpm@linux-foundation.org,
	peterz@infradead.org
Cc: Martin KaFai Lau <kafai@fb.com>, Song Liu <songliubraving@fb.com>,
	Yonghong Song <yhs@fb.com>,
	netdev@vger.kernel.org, bpf@vger.kernel.org
Subject: [PATCH 3/3] module: Properly propagate MODULE_STATE_COMING failure
Date: Mon, 24 Jun 2019 11:18:46 +0200	[thread overview]
Message-ID: <20190624092109.863781858@infradead.org> (raw)
In-Reply-To: 20190624091843.859714294@infradead.org

Now that notifiers got unbroken; use the proper interface to handle
notifier errors and propagate them.

There were already MODULE_STATE_COMING notifiers that failed; notably:

 - jump_label_module_notifier()
 - tracepoint_module_notify()
 - bpf_event_notify()

By propagating this error, we fix those users.

Cc: Jessica Yu <jeyu@kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Martin KaFai Lau <kafai@fb.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: Yonghong Song <yhs@fb.com>
Cc: linux-kernel@vger.kernel.org
Cc: netdev@vger.kernel.org
Cc: bpf@vger.kernel.org
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
 kernel/module.c |    7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

--- a/kernel/module.c
+++ b/kernel/module.c
@@ -3643,9 +3643,10 @@ static int prepare_coming_module(struct
 	if (err)
 		return err;
 
-	blocking_notifier_call_chain(&module_notify_list,
-				     MODULE_STATE_COMING, mod);
-	return 0;
+	err = blocking_notifier_call_chain_error(&module_notify_list,
+			MODULE_STATE_COMING, MODULE_STATE_GOING, mod);
+
+	return notifier_to_errno(err);
 }
 
 static int unknown_module_param_cb(char *param, char *val, const char *modname,


