linux-kernel - [PATCH] x86: fix error paths in microcode

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Date:	Fri, 02 Dec 2011 13:35:19 +0000
From:	"Jan Beulich" <JBeulich@...e.com>
To:	<mingo@...e.hu>, <tglx@...utronix.de>, <hpa@...or.com>
Cc:	<linux-kernel@...r.kernel.org>
Subject: [PATCH] x86: fix error paths in microcode_init()

After failure of platform_device_register_simple(), microcode_dev_exit()
got called without the call to microcode_dev_init() already having taken
place.

After failure of microcode_dev_init(), no cleanup of previously carried
out setup was done at all.

As a result, microcode_dev_exit() can now get __exit tagged on it.

(Noticed while looking at the code, not because of having experienced
an actual problem.)

Signed-off-by: Jan Beulich <jbeulich@...e.com>

---
 arch/x86/kernel/microcode_core.c |   18 +++++++++++++-----
 1 file changed, 13 insertions(+), 5 deletions(-)

--- 3.2-rc4/arch/x86/kernel/microcode_core.c
+++ 3.2-rc4-x86-ucode-init-eh/arch/x86/kernel/microcode_core.c
@@ -256,7 +256,7 @@ static int __init microcode_dev_init(voi
 	return 0;
 }
 
-static void microcode_dev_exit(void)
+static void __exit microcode_dev_exit(void)
 {
 	misc_deregister(&microcode_dev);
 }
@@ -519,10 +519,8 @@ static int __init microcode_init(void)
 
 	microcode_pdev = platform_device_register_simple("microcode", -1,
 							 NULL, 0);
-	if (IS_ERR(microcode_pdev)) {
-		microcode_dev_exit();
+	if (IS_ERR(microcode_pdev))
 		return PTR_ERR(microcode_pdev);
-	}
 
 	get_online_cpus();
 	mutex_lock(&microcode_mutex);
@@ -538,8 +536,18 @@ static int __init microcode_init(void)
 	}
 
 	error = microcode_dev_init();
-	if (error)
+	if (error) {
+		get_online_cpus();
+		mutex_lock(&microcode_mutex);
+
+		sysdev_driver_unregister(&cpu_sysdev_class, &mc_sysdev_driver);
+
+		mutex_unlock(&microcode_mutex);
+		put_online_cpus();
+
+		platform_device_unregister(microcode_pdev);
 		return error;
+	}
 
 	register_syscore_ops(&mc_syscore_ops);
 	register_hotcpu_notifier(&mc_cpu_notifier);



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