On Mon, 1 Sep 2025 10:43:36 +0100 Mark Rutland <mark.rutl...@arm.com> wrote:
> > So, __copy_from_user_inatomic() is supposed to be called if > > pagefault_disable() has already been called? If this is the case, can we > > add more comments to this code? > > Just to check, you're asking for better comments in <linux/uaccess.h>, > right? Yes. > > > I've been using the inatomic() version this > > way in preempt disabled locations since 2016. > > > > Looks like it needs to be converted to copy_from_user_nofault(). > > > > Luo, this version of the patch looks legit, no need for a v2. > > > > I just wanted to figure out why __copy_from_user_inatomic() wasn't atomic. > > If anything, it needs to be better documented. > > If that had roughly the same kerneldoc comment as for > __copy_to_user_inatomic(), would that be sufficient, or do you think > both need to be made more explicit? Yeah, it would have been very helpful to have that. Note, my use of __copy_from_user_inatomic() was added before copy_from_user_nofault() existed. So it would likely not have been helpful back then ;-) I think even adding a comment to the kerneldoc of these functions with something like: You probably want to use copy_from/to_user_nofault(). These are more for internal handling, and should be avoided unless you really know what you are doing. -- Steve
