Messages in this thread | | | From | Arnd Bergmann <> | Subject | Re: [PATCH 15/25] autofs: move ioctl32 to autofs{,4}/root.c | Date | Mon, 7 Nov 2005 11:36:18 +0100 |
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On Sünndag 06 November 2005 07:22, Ian Kent wrote: > On Sat, 5 Nov 2005, Arnd Bergmann wrote: > > I'm not sure if I like conditional compilation in the code proper but I'll > leave it to you to make the final decision since your running with the > change. Is there a reason the definitions can't simply be left in place?
I think the compat_ptr() macro is not defined on architectures that don't have 32 bit compat code, but we could change that.
> Its been a while since I trawled through the compat ioctl code (please > point me to the right place) but with this change I think that the > AUTOFS_IOC_SETTIMEOUT32 is redundant. Consider a conditional define for > AUTOFS_IOC_SETTIMEOUT in include/linux/auto_fs.h instead. Both autofs and > autofs4 use that definition.
The point here is that the two are different on 64 bit platforms, since sizeof (int) != sizeof (long). You also can't do
switch (cmd) { case AUTOFS_IOC_SETTIMEOUT32: case AUTOFS_IOC_SETTIMEOUT: return do_stuff(); }
because then gcc would complain about duplicate case targets on 32 bit targets. > The lock_kernel()/unlock_kernel() in the autofs4 patch is ineffective as > the BKL is not used for syncronisation anywhere else in autofs4. If > removing it causes problems I need to know about'em so I can fix'em > (hopefully).
I used the BKL here in order to maintain the current semantics, because ioctl is always called with BKL held, and compat_ioctl is called without it.
If you are sure you don't need the BKL, then you should also replace ".ioctl = ..." with ".unlocked_ioctl = ...".
Arnd <>< - 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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