On Tue, Mar 16, 2021 at 4:51 PM Russell King - ARM Linux admin <linux@xxxxxxxxxxxxxxx> wrote: > On Tue, Mar 16, 2021 at 04:44:45PM +0100, Arnd Bergmann wrote: > > On Tue, Mar 16, 2021 at 11:17 AM Dmitry Vyukov <dvyukov@xxxxxxxxxx> wrote: > > > The compiler is gcc version 10.2.1 20210110 (Debian 10.2.1-6) > > > > Ok, building with Ubuntu 10.2.1-1ubuntu1 20201207 locally, that's > > the closest I have installed, and I think the Debian and Ubuntu versions > > are generally quite close in case of gcc since they are maintained by > > the same packagers. > > ... which shouldn't be a problem - that's just over 1/4 of the stack > space. Could it be the syzbot's gcc is doing something weird and > inflating the stack frames? It's possible, I think that's really unlikely given that it's just Debian's gcc, which is as close to mainline as the version I was using. Uwe's DEBUG_STACKOVERFLOW patch from a while ago might help if this was the problem though: https://lore.kernel.org/linux-arm-kernel/20200108082913.29710-1-u.kleine-koenig@xxxxxxxxxxxxxx/ My best guess is something going wrong in the interrupt that triggered the preempt_schedule() which ended up calling task_stack_end_corrupted() in schedule_debug(), as you suggested earlier. Arnd
