Re: perf: perf_fuzzer triggers NULL pointer dereference

From: Vince Weaver
Date: Thu Nov 08 2018 - 11:05:12 EST


On Thu, 8 Nov 2018, Vince Weaver wrote:

> [91760.326510] BUG: unable to handle kernel NULL pointer dereference at 0000000000000000
> [91760.334876] PGD 0 P4D 0
> [91760.337596] Oops: 0000 [#1] SMP PTI
> [91760.341332] CPU: 6 PID: 0 Comm: swapper/6 Tainted: G W 4.20.0-rc1+ #119
> [91760.349816] Hardware name: LENOVO 10AM000AUS/SHARKBAY, BIOS FBKT72AUS 01/26/2014
> [91760.357723] RIP: 0010:perf_prepare_sample+0x82/0x4a0

so what's the best way to do the equivelent of addr2line on something like
this, now that we aren't allowed to know the RIP anymore?

I probably knew at one point but I've spent the last 3 months doing 6502
assembly language Demoscene coding and so apparently I've forgotten
everything I once knew about x86_64 kernel interfaces. (As can be
imagined, Demoscene coding work is a lot more mentally rewarding than
perf_fuzzer work).

Vince