Messages in this thread | | | Date | Mon, 29 Dec 2003 20:13:28 +0000 | From | viro@parcelfa ... | Subject | Re: [PATCH] drivers/cdrom/isp16.c check_region() fix |
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On Mon, Dec 29, 2003 at 02:42:23PM -0500, Omkhar Arasaratnam wrote: > check_region is depreciated in 2.6, this replaces it with request_region > > As this is my first patch to the kernel, please let me know if I did anything wrong
It's pointless - the reason why check_region() is bad applies to your code. The problem with check_region() is simple - it gives no protection against somebody else grabbing the ports in question just as you've got "it's free" from check_region(). The same problem exists with your replacement - as soon as you've released the region it could've been grabbed by anybody.
Note that there's another problem - on rmmod we release the region we hadn't grabbed. Proper fix is a) replace check_region with request_region b) check that we don't have any IO on those ports before that point (surprisingly many drivers are buggy that way - they do some IO and then go "oops, looks like somebody held these ports after all; oh, well, let's hope we hadn't screwed them too badly"). AFAICS isp16 is OK in that repect, though. c) make sure that we release that region on all failure exits past that point, so that insmod failure would not leave it grabbed. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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