cdev_add() can fail. The driver currently ignores the return value and
reports probe success even when the cdev was not registered, leaving a
chrdev region allocated with no working file operations.
Check the return value, emit an error, and unwind the chrdev region and
platform device on failure.
Fixes: 635adb6cd25c ("[PATCH] scx200_gpio: use 1 cdev for N minors, not N for N")
Signed-off-by: Linkai Gong <gonglinkai@kylinos.cn>
---
v2:
- Use "if (rc)" instead of "if (rc < 0)" as suggested by Greg
drivers/char/scx200_gpio.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/drivers/char/scx200_gpio.c b/drivers/char/scx200_gpio.c
index 700e6affea6f..3ec17832e9c9 100644
--- a/drivers/char/scx200_gpio.c
+++ b/drivers/char/scx200_gpio.c
@@ -107,10 +107,16 @@ static int __init scx200_gpio_init(void)
}
cdev_init(&scx200_gpio_cdev, &scx200_gpio_fileops);
- cdev_add(&scx200_gpio_cdev, devid, MAX_PINS);
+ rc = cdev_add(&scx200_gpio_cdev, devid, MAX_PINS);
+ if (rc) {
+ dev_err(&pdev->dev, "cdev_add err: %d\n", rc);
+ goto undo_chrdev_region;
+ }
return 0; /* succeed */
+undo_chrdev_region:
+ unregister_chrdev_region(devid, MAX_PINS);
undo_platform_device_add:
platform_device_del(pdev);
undo_malloc:
--
2.25.1