On Fri, 2020-05-29 at 06:14:46 UTC, Daniel Axtens wrote: > syzkaller is picking up a bunch of crashes that look like this: > > Unrecoverable exception 380 at c00000000037ed60 (msr=8000000000001031) > Oops: Unrecoverable exception, sig: 6 [#1] > LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries > Modules linked in: > CPU: 0 PID: 874 Comm: syz-executor.0 Not tainted > 5.7.0-rc7-syzkaller-00016-gb0c3ba31be3e #0 > NIP: c00000000037ed60 LR: c00000000004bac8 CTR: c000000000030990 > REGS: c0000000555a7230 TRAP: 0380 Not tainted > (5.7.0-rc7-syzkaller-00016-gb0c3ba31be3e) > MSR: 8000000000001031 <SF,ME,IR,DR,LE> CR: 48222882 XER: 20000000 > CFAR: c00000000004bac4 IRQMASK: 0 > GPR00: c00000000004bb68 c0000000555a74c0 c0000000024b3500 0000000000000005 > GPR04: 0000000000000000 0000000000000000 c00000000004bb88 c008000000910000 > GPR08: 00000000000b0000 c00000000004bac8 0000000000016000 c000000002503500 > GPR12: c000000000030990 c000000003190000 00000000106a5898 00000000106a0000 > GPR16: 00000000106a5890 c000000007a92000 c000000008180e00 c000000007a8f700 > GPR20: c000000007a904b0 0000000010110000 c00000000259d318 5deadbeef0000100 > GPR24: 5deadbeef0000122 c000000078422700 c000000009ee88b8 c000000078422778 > GPR28: 0000000000000001 800000000280b033 0000000000000000 c0000000555a75a0 > NIP [c00000000037ed60] __sanitizer_cov_trace_pc+0x40/0x50 > LR [c00000000004bac8] interrupt_exit_kernel_prepare+0x118/0x310 > Call Trace: > [c0000000555a74c0] [c00000000004bb68] > interrupt_exit_kernel_prepare+0x1b8/0x310 (unreliable) > [c0000000555a7530] [c00000000000f9a8] interrupt_return+0x118/0x1c0 > --- interrupt: 900 at __sanitizer_cov_trace_pc+0x0/0x50 > ...<random previous call chain>... > > That looks like the KCOV helper accessing memory that's not safe to > access in the interrupt handling context. > > Do not instrument the new syscall entry/exit code with KCOV, GCOV or > UBSAN. > > Cc: Nicholas Piggin <npig...@gmail.com> > Fixes: 68b34588e202 ("powerpc/64/sycall: Implement syscall entry/exit logic > in C") > Signed-off-by: Daniel Axtens <d...@axtens.net>
Applied to powerpc fixes, thanks. https://git.kernel.org/powerpc/c/2f26ed1764b42a8c40d9c48441c73a70d805decf cheers