On Sun, 01 May, at 12:34:29AM, Arnd Bergmann wrote: > > The sys_restart() system call takes a mutex before calling kernel_restart() > or kernel_poweroff(). > > I've had a closer look now and found that there are a few other > callers of kernel_restart, so I guess if you restart using sysctl > at the exact same time as calling /sbin/reboot, things may break. Right. Or if the dm-verify-target driver saw an error.
> It's not something we'd have to worry about in practice, but it does > make my patch incorrect. Should we come up with a different way to > do it? Jeremy proposed a patch to dynamically allocate the memory, which I think is the correct way to go given that our (reasonable) assumptions about reboot notifier concurrency are not guaranteed, https://lkml.kernel.org/r/87h9eked24....@jcompost-mobl1.tl.intel.com
