Re: [PATCH] x86: Implement __WARN using UD0
From: Borislav Petkov
Date: Sat Feb 25 2017 - 14:39:50 EST
On Sat, Feb 25, 2017 at 09:55:45AM -0800, hpa@xxxxxxxxx wrote:
> You mean like the INT instruction?
Right, you mentioned reusing INT $9 upthread.
That doesn't have the additional info in the immed8 - it is the vector
in this case. But that's not really important for our usage.
In any case, the hw does react to it when I do
"int $9"
so I guess we could look into using that one.
[ 93.668930] test: loading out-of-tree module taints kernel.
[ 93.674785] Starting test.
[ 93.677571] coprocessor segment overrun: 0000 [#1] PREEMPT SMP
[ 93.683459] Modules linked in: test(O+) xfs libcrc32c exportfs snd_hda_codec_hdmi snd_hda_codec_realtek snd_hda_coded
[ 93.683489] CPU: 4 PID: 2136 Comm: insmod Tainted: G O 4.10.0-rc7+ #7
[ 93.683500] Hardware name: MICRO-STAR INTERNATIONAL CO.,LTD MS-7599/870-C45 (MS-7599), BIOS V1.15 03/04/2011
[ 93.683503] task: ffff88012f154380 task.stack: ffffc90006cf4000
[ 93.683512] RIP: 0010:test_init+0x17/0x20 [test]
[ 93.683515] RSP: 0018:ffffc90006cf7cb8 EFLAGS: 00000296
[ 93.683518] RAX: 000000000000000e RBX: ffffffffa03ca0c0 RCX: 0000000000000000
[ 93.683521] RDX: 000000000000000e RSI: ffffffff802d4e48 RDI: ffffffff802d4e48
[ 93.683523] RBP: ffffc90006cf7cb8 R08: 0000000000000000 R09: 0000000000000274
[ 93.683525] R10: 0000000000000000 R11: 0000000000000273 R12: ffffffffa03ca000
[ 93.683527] R13: 0000000000000000 R14: 0000000000000001 R15: ffffc90006cf7eb0
[ 93.683530] FS: 00007f55d1e3e700(0000) GS:ffff880136d00000(0000) knlGS:0000000000000000
[ 93.683533] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 93.683535] CR2: 000055be657f51e8 CR3: 0000000131014000 CR4: 00000000000006e0
[ 93.683537] Call Trace:
[ 93.683548] do_one_initcall+0x53/0x1a0
[ 93.683554] ? __vunmap+0xaa/0xf0
[ 93.683559] ? kfree+0x151/0x1b0
[ 93.683566] do_init_module+0x5f/0x1d5
[ 93.683573] load_module+0x2026/0x2530
[ 93.683578] ? __symbol_put+0x80/0x80
[ 93.683589] SYSC_finit_module+0xcb/0xd0
[ 93.683597] SyS_finit_module+0xe/0x10
[ 93.683602] entry_SYSCALL_64_fastpath+0x18/0xa8
[ 93.683605] RIP: 0033:0x7f55d1970a59
[ 93.683607] RSP: 002b:00007ffc3cf781d8 EFLAGS: 00000206 ORIG_RAX: 0000000000000139
[ 93.683610] RAX: ffffffffffffffda RBX: 00007f55d1c2ab78 RCX: 00007f55d1970a59
[ 93.683612] RDX: 0000000000000000 RSI: 000055be655d73d9 RDI: 0000000000000003
[ 93.683614] RBP: 000000000000270f R08: 0000000000000000 R09: 00007f55d1c2cf00
[ 93.683616] R10: 0000000000000003 R11: 0000000000000206 R12: 00007f55d1c2ab78
[ 93.683618] R13: 0000000000001020 R14: 00007f55d1c2ab78 R15: 00007f55d1c2ab20
[ 93.683623] Code: <31> c0 5d c3 0f 1f 44 00 00 0f 1f 44 00 00 55 48 c7 c7 6e a0 3c a0
[ 93.683655] RIP: test_init+0x17/0x20 [test] RSP: ffffc90006cf7cb8
[ 93.683699] ---[ end trace e034b65a8bb8cf26 ]---
[ 93.683702] Kernel panic - not syncing: Fatal exception
[ 93.709252] Kernel Offset: disabled
--
Regards/Gruss,
Boris.
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