[PATCH 2/3] staging: dgap: implement proper error handling in dgap_start()

[Alexey Khoroshilov]

dgap_start() ignored errors in class_create() and device_create().
The patch implements proper error handling.

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Alexey Khoroshilov <khoroshilov@xxxxxxxxx>
---
 drivers/staging/dgap/dgap_driver.c | 42 +++++++++++++++++++++++++++++++-------
 1 file changed, 35 insertions(+), 7 deletions(-)

diff --git a/drivers/staging/dgap/dgap_driver.c b/drivers/staging/dgap/dgap_driver.c
index d7f1e999aaa4..136c879b560c 100644
--- a/drivers/staging/dgap/dgap_driver.c
+++ b/drivers/staging/dgap/dgap_driver.c
@@ -279,6 +279,7 @@ static int dgap_start(void)
 {
 	int rc = 0;
 	unsigned long flags;
+	struct device *device;
 
         /* make sure that the globals are init'd before we do anything else */
         dgap_init_globals();
@@ -303,12 +304,29 @@ static int dgap_start(void)
 	}
 
 	dgap_class = class_create(THIS_MODULE, "dgap_mgmt");
-	device_create(dgap_class, NULL,
-		MKDEV(DIGI_DGAP_MAJOR, 0),
-		NULL, "dgap_mgmt");
-	device_create(dgap_class, NULL,
-		MKDEV(DIGI_DGAP_MAJOR, 1),
-		NULL, "dgap_downld");
+	if (IS_ERR(dgap_class)) {
+		rc = PTR_ERR(dgap_class);
+		APR(("Can't create dgap_mgmt class (%d)\n", rc));
+		goto failed_class;
+	}
+
+	device = device_create(dgap_class, NULL,
+			MKDEV(DIGI_DGAP_MAJOR, 0),
+			NULL, "dgap_mgmt");
+	if (IS_ERR(device)) {
+		rc = PTR_ERR(device);
+		APR(("Can't create device (%d)\n", rc));
+		goto failed_device0;
+	}
+
+	device = device_create(dgap_class, NULL,
+			MKDEV(DIGI_DGAP_MAJOR, 1),
+			NULL, "dgap_downld");
+	if (IS_ERR(device)) {
+		rc = PTR_ERR(device);
+		APR(("Can't create device (%d)\n", rc));
+		goto failed_device1;
+	}
 
 	/*
 	 * Init any global tty stuff.
@@ -316,7 +334,7 @@ static int dgap_start(void)
 	rc = dgap_tty_preinit();
 	if (rc < 0) {
 		APR(("tty preinit - not enough memory (%d)\n", rc));
-		return(rc); 
+		goto failed_tty;
 	}
 
 	/* Start the poller */
@@ -333,6 +351,16 @@ static int dgap_start(void)
 	dgap_driver_state = DRIVER_NEED_CONFIG_LOAD;
 
 	return (rc);
+
+failed_tty:
+	device_destroy(dgap_class, MKDEV(DIGI_DGAP_MAJOR, 1));
+failed_device1:
+	device_destroy(dgap_class, MKDEV(DIGI_DGAP_MAJOR, 0));
+failed_device0:
+	class_destroy(dgap_class);
+failed_class:
+	unregister_chrdev(DIGI_DGAP_MAJOR, "dgap");
+	return (rc);
 }
 
 
-- 
1.8.3.2

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