Re: [PATCH v3] eventpoll: Fix priority inversion problem

[Nam Cao <namcao@linutronix.de>]

On Thu, Jul 10, 2025 at 05:48:08AM +0200, Nam Cao wrote:
> On Thu, Jul 10, 2025 at 11:08:18AM +0800, Xi Ruoyao wrote:
> > After upgrading my kernel to the recent mainline I've encountered some
> > stability issue, like:
> > 
> > - When GDM started gnome-shell, the screen often froze and the only
> > thing I could do was to switch into a VT and reboot.
> > - Sometimes gnome-shell started "fine" but then starting an application
> > (like gnome-console) needed to wait for about a minute.
> > - Sometimes the system shutdown process hangs waiting for a service to
> > stop.
> > - Rarely the system boot process hangs for no obvious reason.
> > 
> > Most strangely in all the cases there are nothing alarming in dmesg or
> > system journal.
> > 
> > I'm unsure if this is the culprit but I'm almost sure it's the trigger.
> > Maybe there's some race condition in my userspace that the priority
> > inversion had happened to hide...  but anyway reverting this patch
> > seemed to "fix" the issue.
> > 
> > Any thoughts or pointers to diagnose further?

I fetched Linus's tree, and noticed that the latest commit in Linus tree
fixes an use-after-free issue in eventpoll:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=8c2e52ebbe885c7eeaabd3b7ddcdc1246fc400d2

Any chance it resolves your issue?

Nam