On Fri, Aug 29, 2025 at 06:13:11PM -0400, Steven Rostedt wrote:

On Fri, 29 Aug 2025 20:53:40 +0100
Catalin Marinas [off-list ref] wrote:
valid user address.

quoted

BTW, arm64 also bails out early in do_page_fault() if in_atomic() but I
suspect that's not the case here.

Adding Al Viro since since he wrote a large part of uaccess.h.

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?

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?

Mark.