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Message-Id: <20191007082700.14428791.6@infradead.org>
User-Agent: quilt/0.65
Date:   Mon, 07 Oct 2019 10:25:44 +0200
From:   Peter Zijlstra <peterz@infradead.org>
To:     x86@kernel.org
Cc:     peterz@infradead.org, linux-kernel@vger.kernel.org,
        rostedt@goodmis.org, mhiramat@kernel.org, bristot@redhat.com,
        jbaron@akamai.com, torvalds@linux-foundation.org,
        tglx@linutronix.de, mingo@kernel.org, namit@vmware.com,
        hpa@zytor.com, luto@kernel.org, ard.biesheuvel@linaro.org,
        Yonghong Song <yhs@fb.com>,
        Alexei Starovoitov <ast@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
        Song Liu <songliubraving@fb.com>, Jessica Yu <jeyu@kernel.org>,
        Martin KaFai Lau <kafai@fb.com>
Subject: [PATCH v2 3/4] module: Properly propagate MODULE_STATE_COMING failure
References: <20191007082541.64146933.7@infradead.org>
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Sender: linux-kernel-owner@vger.kernel.org
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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.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Yonghong Song <yhs@fb.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Song Liu <songliubraving@fb.com>
Cc: Jessica Yu <jeyu@kernel.org>
Cc: Martin KaFai Lau <kafai@fb.com>
---
 kernel/module.c |   10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

--- a/kernel/module.c
+++ b/kernel/module.c
@@ -3751,9 +3751,13 @@ 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_robust(&module_notify_list,
+			MODULE_STATE_COMING, MODULE_STATE_GOING, mod);
+	err = notifier_to_errno(err);
+	if (err)
+		klp_module_going(mod);
+
+	return err;
 }
 
 static int unknown_module_param_cb(char *param, char *val, const char *modname,