Re: [LKP] [x86/jump_table] b34006c425: BUG:unable_to_handle_kernel

[Ard Biesheuvel]

On Thu, 6 Dec 2018 at 10:17, kernel test robot <rong.a.chen@xxxxxxxxx> wrote:
>
> FYI, we noticed the following commit (built with gcc-7):
>
> commit: b34006c4258c9c86597b6b7123d6a9a3513d6cd7 ("x86/jump_table: Use relative references")
> https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git master
>
> in testcase: boot
>
> on test machine: qemu-system-x86_64 -enable-kvm -cpu SandyBridge -smp 2 -m 4G
>
> caused below changes (please refer to attached dmesg/kmsg for entire log/backtrace):
>
>
> +------------------------------------------+------------+------------+
> |                                          | 9fc0f798ab | b34006c425 |
> +------------------------------------------+------------+------------+
> | boot_successes                           | 4          | 0          |
> | boot_failures                            | 0          | 4          |
> | BUG:unable_to_handle_kernel              | 0          | 4          |
> | Oops:#[##]                               | 0          | 4          |
> | RIP:memcmp                               | 0          | 4          |
> | Kernel_panic-not_syncing:Fatal_exception | 0          | 4          |
> +------------------------------------------+------------+------------+
>

>From the attached log:
[    0.000000] Linux version 4.19.0-rc5-00006-gb34006c

while

$ git tag --contains b34006c
v4.20-rc1
v4.20-rc2
v4.20-rc3
v4.20-rc4
v4.20-rc5

If this is reproducible on a clean rebuild of b34006c425, I'm happy to
look into it.



> [   21.261613] BUG: unable to handle kernel paging request at 0000000001001893
> [   21.262316] PGD 0 P4D 0
> [   21.262578] Oops: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC PTI
> [   21.263139] CPU: 1 PID: 252 Comm: systemd-udevd Not tainted 4.19.0-rc5-00006-gb34006c #1
> [   21.263952] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014
> [   21.264797] RIP: 0010:memcmp+0x7/0x1d
> [   21.265179] Code: 39 ca 75 e7 41 c6 41 01 00 c3 c3 48 01 fa 48 89 f8 48 39 d0 74 0c 0f b6 08 39 f1 74 05 48 ff c0 eb ef c3 31 c9 48 39 d1 74 13 <0f> b6 04 0f 44 0f b6 04 0e 48 ff c1 44 29 c0 74 ea eb 02 31 c0 c3
> [   21.267043] RSP: 0018:ffff880110aebc50 EFLAGS: 00010293
> [   21.267579] RAX: ffffffff8101b80d RBX: 0000000001001893 RCX: 0000000000000000
> [   21.268299] RDX: 0000000000000005 RSI: ffff880110aebc6b RDI: 0000000001001893
> [   21.269015] RBP: ffffffff824019a4 R08: 0000000000000044 R09: 0000000000000008
> [   21.269736] R10: 0000000701029ae0 R11: ffffffff82a42360 R12: ffffffff8101b80d
> [   21.270458] R13: ffffc90001029ae0 R14: ffffc900010297e0 R15: ffffc900010295e0
> [   21.271185] FS:  00007f22ad10e8c0(0000) GS:ffff88013b300000(0000) knlGS:0000000000000000
> [   21.271989] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [   21.272571] CR2: 0000000001001893 CR3: 0000000110ae6000 CR4: 00000000000406a0
> [   21.273290] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> [   21.274006] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> [   21.274724] Call Trace:
> [   21.274993]  __jump_label_transform+0xb6/0x11f
> [   21.275455]  jump_label_apply_nops+0x5d/0x72
> [   21.275894]  module_finalize+0x18d/0x1c3
> [   21.276323]  load_module+0x1800/0x236d
> [   21.276710]  ? vfs_read+0x108/0x116
> [   21.277068]  ? set_fs+0x9/0x20
> [   21.277390]  ? security_kernel_post_read_file+0x67/0x75
> [   21.277916]  ? allow_write_access+0x13/0x24
> [   21.278346]  ? kernel_read_file+0x1d3/0x1fa
> [   21.278773]  ? __do_sys_finit_module+0xae/0xd4
> [   21.279238]  __do_sys_finit_module+0xae/0xd4
> [   21.279675]  do_syscall_64+0x20f/0x224
> [   21.280063]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
> [   21.280602] RIP: 0033:0x7f22abf8b229
> [   21.280970] Code: 00 f3 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 3f 4c 2b 00 f7 d8 64 89 01 48
> [   21.282830] RSP: 002b:00007fff5c9d38e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000139
> [   21.283599] RAX: ffffffffffffffda RBX: 000055e996bd96b0 RCX: 00007f22abf8b229
> [   21.284316] RDX: 0000000000000000 RSI: 00007f22ac8a4265 RDI: 0000000000000007
> [   21.285027] RBP: 00007f22ac8a4265 R08: 0000000000000000 R09: 000055e996bcd860
> [   21.285743] R10: 0000000000000007 R11: 0000000000000246 R12: 0000000000000000
> [   21.286459] R13: 000055e996bd04d0 R14: 0000000000020000 R15: 000055e996439cbc
> [   21.287186] Modules linked in: button(+) ip_tables x_tables ipv6
> [   21.287800] CR2: 0000000001001893
>          Starting LSB: Execute the kexec -e command to reboot system...
> [   21.346498] input: Power Button as /devices/LNXSYSTM:00/LNXPWRBN:00/input/input4
> [   21.347338] evbug: Connected device: input4 (Power Button at LNXPWRBN/button/input0)
> [   21.347665] ---[ end trace 3282d04b21b84631 ]---
>
>
> To reproduce:
>
>         git clone https://github.com/intel/lkp-tests.git
>         cd lkp-tests
>         bin/lkp qemu -k <bzImage> job-script # job-script is attached in this email
>
>
>
> Thanks,
> lkp