From fb8f7ba077b5c665432082ab205bcd2cb01f6a3c Mon Sep 17 00:00:00 2001 From: Alexey Dobriyan Date: Sat, 24 Mar 2007 15:58:12 +0300 Subject: [WATCHDOG] Semi-typical watchdog bug re early misc_register() It seems that some watchdog drivers are doing following mistake: rv = misc_register(); if (rv < 0) return rv; rv = request_region(); if (rv < 0) { misc_deregister(); return rv; } But, right after misc_register() returns, misc device can be opened and ioctls interacting with hardware issued, and driver can do outb() to port it doesn't own yet, because request_region() is still pending. Here is my patch, compile-tested only. Signed-off-by: Alexey Dobriyan Signed-off-by: Wim Van Sebroeck --- drivers/char/watchdog/eurotechwdt.c | 22 +++++++++++----------- 1 file changed, 11 insertions(+), 11 deletions(-) (limited to 'drivers/char/watchdog/eurotechwdt.c') diff --git a/drivers/char/watchdog/eurotechwdt.c b/drivers/char/watchdog/eurotechwdt.c index f70387f01b2b..b070324e27a6 100644 --- a/drivers/char/watchdog/eurotechwdt.c +++ b/drivers/char/watchdog/eurotechwdt.c @@ -413,17 +413,10 @@ static int __init eurwdt_init(void) { int ret; - ret = misc_register(&eurwdt_miscdev); - if (ret) { - printk(KERN_ERR "eurwdt: can't misc_register on minor=%d\n", - WATCHDOG_MINOR); - goto out; - } - ret = request_irq(irq, eurwdt_interrupt, IRQF_DISABLED, "eurwdt", NULL); if(ret) { printk(KERN_ERR "eurwdt: IRQ %d is not free.\n", irq); - goto outmisc; + goto out; } if (!request_region(io, 2, "eurwdt")) { @@ -438,6 +431,13 @@ static int __init eurwdt_init(void) goto outreg; } + ret = misc_register(&eurwdt_miscdev); + if (ret) { + printk(KERN_ERR "eurwdt: can't misc_register on minor=%d\n", + WATCHDOG_MINOR); + goto outreboot; + } + eurwdt_unlock_chip(); ret = 0; @@ -448,14 +448,14 @@ static int __init eurwdt_init(void) out: return ret; +outreboot: + unregister_reboot_notifier(&eurwdt_notifier); + outreg: release_region(io, 2); outirq: free_irq(irq, NULL); - -outmisc: - misc_deregister(&eurwdt_miscdev); goto out; } -- cgit v1.2.3-55-g7522