easy way to detect infinite loop in kernel of the linux

I've just spent my 2 extra hours trying to find bug in my modification of the kernel of the linux, every time when I was connecting module to the kernel it was good but when I unconnected it my mouse stopped to work, so using printk I found infinite loop, my question is does somebody know nice techniques to detect such bugs, sometimes it is difficult to fi开发者_开发技巧nd such loops, and linux becomes unpredictable, so how can I avoid infinite loops in kernel thanks in advance

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There is some infrastructure in the kernel that allows you to detect some lockup conditions :

CONFIG_DETECT_SOFTLOCKUP

CONFIG_DETECT_HUNG_TASK

And the various lock checking function you can find in the "Kernel Hacking" section of the kernel config

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I've always found printk useful for that, as you did.

Other options would be running your kernel in Bochs in debugging mode. And as I recall, there's a way of running the kernel in gdb. Google can help with those options.

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Oh, you said "avoid" not "debug"... hmm, the best way to avoid is do not hack the kernel :^)

Seriously, when doing kernel-level programming you have to be extra careful. Add a main() to the code that stress-tests your routines in usermode before adding to the running kernel. And read over your code, especially after you've isolated the bug to a particular section. I once found an infinite loop in LynxOS's terminal driver when some ANSI art hung the operating system. Some junior programmer, apparently, had written that part, parsing the escape sequence options as text rather than numbers. The code was so bad, I got disgusted trying to locate the exact error that forced the loop, and just rewrote most of the driver. And tested it in usermode before adding to the kernel.

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You could try to enable the NMI watchdog.