Subject: Re: FVP: kernel BUG at arch/arm64/kernel/traps.c:497 - Internal error: Oops - BUG: 0

From: Mark Rutland <[email-masked]>
Date: Tue, 12 Jul 2022 17:21:00 +0100

On Tue, Jul 12, 2022 at 01:49:55PM +0100, Mark Rutland wrote:
> On Tue, Jul 12, 2022 at 03:27:09PM +0530, Naresh Kamboju wrote:
> > [    0.500613] ------------[ cut here ]------------
> > [    0.500709] kernel BUG at arch/arm64/kernel/traps.c:497!
> > [    0.500777] Internal error: Oops - BUG: 0 [#1] PREEMPT SMP
> > [    0.500860] Modules linked in:
> > [    0.500947] CPU: 0 PID: 1 Comm: swapper/0 Tainted: G        W
> >    5.19.0-rc6-next-20220711 #1
> > [    0.501034] Hardware name: FVP Base RevC (DT)
> > [    0.501109] pstate: 00400009 (nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
> > [    0.501209] pc : do_undefinstr+0x284/0x2b4
> > [    0.501381] lr : do_undefinstr+0x150/0x2b4
> > [    0.501509] sp : ffff80000affbbc0
> > [    0.501509] x29: ffff80000affbbc0 x28: ffff000800330000 x27: ffff800009f00444
> > [    0.501759] x26: ffff800009fe6038 x25: 0000000000000001 x24: ffff80000a115968
> > [    0.501923] x23: 0000000040400009 x22: ffff800009f80de0 x21: ffff80000affbd90
> > [    0.502109] x20: 0000000001000000 x19: ffff80000affbc40 x18: ffffffffffffffff
> > [    0.502309] x17: 000000000000003f x16: 000000000000000a x15: ffff0008002b1a1c
> > [    0.502422] x14: ffffffffffffffff x13: ffff0008002b1268 x12: 20726f20746e6573
> > [    0.502683] x11: ffff80000aa12950 x10: 0000000000000073 x9 : ffff8000093bcd6c
> > [    0.502856] x8 : 000000003d4d554e x7 : ffff80000affbce0 x6 : 0000000000000001
> > [    0.503030] x5 : ffff80000a9ef000 x4 : ffff80000a9ef2e0 x3 : 0000000000000000
> > [    0.503234] x2 : ffff000800330000 x1 : ffff000800330000 x0 : 0000000040400009
> > [    0.503409] Call trace:
> > [    0.503480]  do_undefinstr+0x284/0x2b4
> > [    0.503562]  el1_undef+0x30/0x60
> > [    0.503709]  el1h_64_sync_handler+0x84/0xd0
> > [    0.503811]  el1h_64_sync+0x64/0x68
> > [    0.503909]  net_sysctl_init+0x8/0x7c
> > [    0.504053]  do_one_initcall+0x50/0x2b0
> > [    0.504158]  kernel_init_freeable+0x24c/0x2d4
> > [    0.504245]  kernel_init+0x30/0x140
> > [    0.504381]  ret_from_fork+0x10/0x20
> > [    0.504509] Code: 17ffff98 a9425bf5 17ffffbb a9025bf5 (d4210000)
> > [    0.504627] ---[ end trace 0000000000000000 ]---
> 
> We should really improve this WARN to something that tells us about the actual
> failing instruction.

FWIW, I've put together a series to improve the reporting here:

  https://lore.kernel.org/linux-arm-kernel/[email-masked]

Thanks,
Mark.