On Fri, Jan 08, 2021 at 10:33:19AM +0100, Dmitry Vyukov wrote: > On Thu, Jan 7, 2021 at 8:06 PM Jeffrey Walton <noloa...@gmail.com> wrote: > > > > On Thu, Jan 7, 2021 at 2:03 PM Jason A. Donenfeld <ja...@zx2c4.com> wrote: > > > > > > On Thu, Jan 7, 2021 at 1:22 PM Dmitry Vyukov <dvyu...@google.com> wrote: > > > > > > > > On Mon, Dec 21, 2020 at 12:23 PM Jason A. Donenfeld <ja...@zx2c4.com> > > > > wrote: > > > > > > > > > > ... > > > > > > > > These UBSAN checks were just enabled recently. > > > > It's indeed super easy to trigger: 133083 VMs were crashed on this > > > > already: > > > > https://syzkaller.appspot.com/bug?extid=8f90d005ab2d22342b6d > > > > So it's one of the top crashers by now. > > > > > > Ahh, makes sense. So it is easily reproducible after all. > > > > > > You're still of the opinion that it's a false positive, right? I > > > shouldn't spend more cycles on this? > > > > You might consider making a test build with -fno-lto in case LTO is > > mucking things up. > > > > Google Posts Patches So The Linux Kernel Can Be LTO-Optimized By > > Clang, > > https://www.phoronix.com/scan.php?page=news_item&px=Linux-Kernel-Clang-LTO-Patches > > Hi Jeff, > > Are these patches upstream now? > syzbot doesn't enable LTO intentionally, nor I see CONFIG_LTO in the > provided config.
Those patches are not upstream yet and LTO will have to be explicitly enabled via config. Cheers, Nathan
