[crash] PANIC: double fault, error_code: 0x0

[Ingo Molnar]

* Ingo Molnar <mingo@xxxxxxxxxx> wrote:

> This is a repost of the latest entry-stack plus Kaiser bits from Andy Lutomirski
> (v3 series from today) and Dave Hansen (kaiser-414-tipwip-20171123 version),
> on top of latest tip:x86/urgent (12a78d43de76).
> 
> This version is pretty well tested, at least on the usual x86 tree test systems.
> It has a couple of merge mistakes fixed, the biggest difference is in patch #22:
> 
>   x86/mm/kaiser: Prepare assembly for entry/exit CR3 switching
> 
> The other patches are identical or very close to what I posted earlier today.

Here's a new bug, on a testsystem I get the double fault boot crash attached 
below. The same bzImage crashes on other systems as well, so it's not CPU 
dependent.

Via Kconfig-bisection I have narrowed it down to the following .config detail: 
it's triggered by _disabling_ CONFIG_DEBUG_ENTRY and enabling CONFIG_KAISER=y.

I.e. one of the sanity checks of CONFIG_DEBUG_ENTRY has some positive side effect. 
I'll try to track down which one it is - any ideas meanwhile?

Thanks,

	Ingo

[    8.797733] calling  pt_dump_init+0x0/0x3b @ 1
[    8.803144] initcall pt_dump_init+0x0/0x3b returned 0 after 1 usecs
[    8.810589] calling  aes_init+0x0/0x11 @ 1
[    8.815757] initcall aes_init+0x0/0x11 returned 0 after 141 usecs
[    8.823020] calling  ghash_pclmulqdqni_mod_init+0x0/0x54 @ 1
[    8.831002] PANIC: double fault, error_code: 0x0
[    8.831002] CPU: 11 PID: 260 Comm: modprobe Not tainted 4.14.0-01419-g1b46550a680d-dirty #17
[    8.831002] Hardware name: Intel Corporation S2600GZ/S2600GZ, BIOS SE5C600.86B.02.02.0002.122320131210 12/23/2013
[    8.831002] task: ffff880828ba8000 task.stack: ffffc90004444000
[    8.831002] RIP: 0010:page_fault+0x11/0x60
[    8.831002] RSP: 0000:ffffffffff0e7fc8 EFLAGS: 00010046
[    8.831002] RAX: 00000000819d4d77 RBX: 0000000000000001 RCX: ffffffff819d4d77
[    8.831002] RDX: 0000000000000003 RSI: 0000000000000010 RDI: ffffffffff0e8078
[    8.831002] RBP: 0000000000000000 R08: 00007ffd7f1aa530 R09: 00007f9407f98400
[    8.831002] R10: 0000000000000007 R11: 0000000000000000 R12: 00007ffd7f1aa680
[    8.831002] R13: 00007f9407f91f80 R14: 0000000000000007 R15: 0000000000000000
[    8.831002] FS:  00007f9407f8f700(0000) GS:ffff88082e640000(0000) knlGS:0000000000000000
[    8.831002] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    8.831002] CR2: ffffffffff0e7fb8 CR3: 0000000828bc4000 CR4: 00000000001406e0
[    8.831002] Call Trace:
[    8.831002]  <SYSENTER>
[    8.831002]  ? __do_page_fault+0x4c0/0x4c0
[    8.831002]  ? page_fault+0x2c/0x60
[    8.831002]  ? native_iret+0x7/0x7
[    8.831002]  ? __do_page_fault+0x4c0/0x4c0
[    8.831002]  ? page_fault+0x2c/0x60
[    8.831002]  ? __entry_text_end+0x1/0x1
[    8.831002]  </SYSENTER>
[    8.831002] Code: ff e8 a4 75 6a ff e9 9f 02 00 00 66 66 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 48 83 c4 88 f6 84 24 88 00 00 00 03 75 20 <e8> 4a 01 00 00 48 89 e7 48 8b 74 24 78 48 c7 44 24 78 ff ff ff 
[    8.831002] Kernel panic - not syncing: Machine halted.
[    8.831002] CPU: 11 PID: 260 Comm: modprobe Not tainted 4.14.0-01419-g1b46550a680d-dirty #17
[    8.831002] Hardware name: Intel Corporation S2600GZ/S2600GZ, BIOS SE5C600.86B.02.02.0002.122320131210 12/23/2013
[    8.831002] Call Trace:
[    8.831002]  <#DF>
[    8.831002]  dump_stack+0x46/0x62
[    8.831002]  panic+0xde/0x221
[    8.831002]  df_debug+0x29/0x30
[    8.831002]  do_double_fault+0x8f/0x120
[    8.831002]  double_fault+0x22/0x30
[    8.831002] RIP: 0010:page_fault+0x11/0x60
[    8.831002] RSP: 0000:ffffffffff0e7fc8 EFLAGS: 00010046
[    8.831002] RAX: 00000000819d4d77 RBX: 0000000000000001 RCX: ffffffff819d4d77
[    8.831002] RDX: 0000000000000003 RSI: 0000000000000010 RDI: ffffffffff0e8078
[    8.831002] RBP: 0000000000000000 R08: 00007ffd7f1aa530 R09: 00007f9407f98400
[    8.831002] R10: 0000000000000007 R11: 0000000000000000 R12: 00007ffd7f1aa680
[    8.831002] R13: 00007f9407f91f80 R14: 0000000000000007 R15: 0000000000000000
[    8.831002]  ? native_iret+0x7/0x7
[    8.831002] WARNING: can't dereference iret registers at ffffffffff0e8048 for ip page_fault+0x11/0x60
[    8.831002]  </#DF>
[    8.831002]  <SYSENTER>
[    8.831002]  ? __do_page_fault+0x4c0/0x4c0
[    8.831002]  ? page_fault+0x2c/0x60
[    8.831002]  ? native_iret+0x7/0x7
[    8.831002]  ? __do_page_fault+0x4c0/0x4c0
[    8.831002]  ? page_fault+0x2c/0x60
[    8.831002]  ? __entry_text_end+0x1/0x1
[    8.831002]  </SYSENTER>
[    8.831002] Kernel Offset: disabled
[    8.831002] Rebooting in 1 seconds..
[    8.831002] ACPI MEMORY or I/O RESET_REG.