On Thu, Jan 05, 2017 at 03:59:52PM +0100, Dmitry Vyukov wrote: > On Thu, Jan 5, 2017 at 3:49 PM, Josh Poimboeuf <jpoimboe@xxxxxxxxxx> wrote: > > On Tue, Dec 27, 2016 at 05:38:59PM +0100, Dmitry Vyukov wrote: > >> On Thu, Dec 22, 2016 at 6:17 AM, Josh Poimboeuf <jpoimboe@xxxxxxxxxx> wrote: > >> > On Wed, Dec 21, 2016 at 01:46:36PM +0100, Andrey Konovalov wrote: > >> >> On Wed, Dec 21, 2016 at 12:36 AM, Josh Poimboeuf <jpoimboe@xxxxxxxxxx> wrote: > >> >> > > >> >> > Thanks. Looking at the stack trace, my guess is that an interrupt hit > >> >> > while running in generated BPF code, and the unwinder got confused > >> >> > because regs->ip points to the generated code. I may need to disable > >> >> > that warning until we figure out a better solution. > >> >> > > >> >> > Can you share your .config file? > >> >> > >> >> Sure, attached. > >> > > >> > Ok, I was able to recreate with your config. The culprit was generated > >> > code, as I suspected, though it wasn't BPF, it was a kprobe (created by > >> > dccpprobe_init()). > >> > > >> > I'll make a patch to disable the warning. > >> > >> Hi, > >> > >> I am also seeing the following warnings: > >> > >> [ 281.889259] WARNING: kernel stack regs at ffff8801c29a7ea8 in > >> syz-executor8:1302 has bad 'bp' value ffff8801c29a7f28 > >> [ 833.994878] WARNING: kernel stack regs at ffff8801c4e77ea8 in > >> syz-executor1:13094 has bad 'bp' value ffff8801c4e77f28 > >> > >> Can it also be caused by bpf/kprobe? > > > > This is a different warning. I suspect it's due to unwinding the stack > > of another CPU while it's running, which is still possible in a few > > places. I'm going to have to disable all these warnings for now. > > > I also have the following diff locally. These loads trigger episodic > KASAN warnings about stack-of-bounds reads on rcu stall warnings when > it does backtrace of all cpus. > If it looks correct to you, can you please also incorporate it into your patch? Ok, will do. BTW, I think there's an issue with your mail client. Your last two replies to me didn't have me on To/Cc. -- Josh -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>