Re: [PATCH] tracing: Fix tracing_marker may trigger page fault during preempt_disable
From: Steven Rostedt <rostedt@goodmis.org>
Date: 2025-08-29 22:12:52
Also in:
linux-arm-kernel, lkml
From: Steven Rostedt <rostedt@goodmis.org>
Date: 2025-08-29 22:12:52
Also in:
linux-arm-kernel, lkml
On Fri, 29 Aug 2025 20:53:40 +0100 Catalin Marinas [off-list ref] wrote: valid user address.
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? 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. -- Steve