Marco Elver <el...@google.com> writes: > Since KCSAN instrumentation is everywhere, we need to treat the hooks > NMI-like for interrupt tracing. In order to present an as 'normal' as > possible context to the code called by KCSAN when reporting errors, we > need to update the IRQ-tracing state. > > Tested: Several runs through kcsan-test with different configuration > (PROVE_LOCKING on/off), as well as hours of syzbot testing with the > original config that caught the problem (without CONFIG_PARAVIRT=y, > which appears to cause IRQ state tracking inconsistencies even when > KCSAN remains off, see Link). > > Link: https://lkml.kernel.org/r/0000000000007d3b2d05ac1c3...@google.com > Fixes: 248591f5d257 ("kcsan: Make KCSAN compatible with new IRQ state > tracking") > Reported-by: syzbot+8db9e1ecde74e590a...@syzkaller.appspotmail.com > Co-developed-by: Peter Zijlstra (Intel) <pet...@infradead.org> > Signed-off-by: Marco Elver <el...@google.com> > --- > Patch Note: This patch applies to latest mainline. While current > mainline suffers from the above problem, the configs required to hit the > issue are likely not enabled too often (of course with PROVE_LOCKING on; > we hit it on syzbot though). It'll probably be wise to queue this as > normal on -rcu, just in case something is still off, given the > non-trivial nature of the issue. (If it should instead go to mainline > right now as a fix, I'd like some more test time on syzbot.)
I'd rather stick it into mainline before -rc1. Reviewed-by: Thomas Gleixner <t...@linutronix.de>
