On Wed, Feb 23, 2005 at 06:22:04PM +0000, Jamie Lokier wrote: > Olof Johansson wrote: > > On Wed, Feb 23, 2005 at 07:54:06AM -0800, Linus Torvalds wrote: > > > > > > Otherwise, a preempt attempt in get_user would not be seen > > > > until some future preempt_enable was executed. > > > > > > True. I guess we should have a "preempt_check_resched()" there too. > > > That's > > > what "kunmap_atomic()" does too (which is what we rely on in the other > > > case we do this..) > > > > Ok, this is getting complex enough to warrant get_user_inatomic(), > > which means adding it to every arch's uaccess.h. > > > > Below patch does so. Unfortunately I don't have a Viro setup with cross > > compilers for nearly every arch, so I can't make sure it doesn't break > > anything. But since I pasted the same code everywhere it shouldn't. > > My turn to say uglee.
Yeah, I wasn't entirely happy about it, but it seems that suggestions are coming in on how to do it better. :-) > Firstly, get_user_inatomic is the wrong name. > > "inatomic" in __copy_from_user_inatomic means it's called inside a > non-premptable region (in atomic...). > > Your macro get_user_inatomic is _not_ called inside a > non-preemptable region, so it shouldn't be called "inatomic". > > (A better name is get_user_no_paging). > > Secondly, does this _one_ use (it's not likely to be used elsewhere) > justify copying & pasting the same code into every asm-*/uaccess, > especially when the code is not in any way arch-specific? Arjan suggested creating a linux/uaccess.h that includes asm/uaccess.h, and start moving the users over since that's where the trend is moving anyway (avoiding including asm/* from common code). futex.c would be the first user, and could be followed by more later as a janitorial patch. That'd mean only one addition of the common function instead of having to add it to every arch. > I suggest putting it into futex.c, and make it an inline function > which takes "u32 __user *". Sure, for now that's good enough. Above janitorial work could be done later, if more users get introduced. -Olof - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
