Re: [PATCH 1/3] xen/mce: Add mcelog support for Xen platform (RFC)

[Borislav Petkov <bp@amd64.org>]

On Mon, May 28, 2012 at 02:48:06PM +0000, Liu, Jinsong wrote:
> > An approach which basically same as you suggested but w/ slightly
> > update, is 1). at xen/mcelog.c, do
> > misc_register(&xen_mce_chrdev_device) at xen_late_init_mcelog, define
> > it as device_initcall(xen_late_init_mcelog) --> now linux dd ready,
> > so xen mcelog divice would register successfully; 2). at native
> > mce.c, change 1 line from device_initcall(mcheck_init_device) to
> > device_initcall_sync(mcheck_init_device) --> so
> > misc_register(&mce_chrdev_device) would be blocked by xen mcelog
> > device;      
> > 
> > I have draft test it and works fine.
> > Thought?
> > 
> 
> =====================
> RFC patch attached:
> =====================
> 
> 
> From d06e667632507d7ed8e18f952b0eb7cec3cfc55c Mon Sep 17 00:00:00 2001
> From: Liu, Jinsong <jinsong.liu@intel.com>
> Date: Tue, 29 May 2012 06:13:19 +0800
> Subject: [PATCH 1/3] xen/mce: Add mcelog support for Xen platform
> 
> When MCA error occurs, it would be handled by Xen hypervisor first,
> and then the error information would be sent to initial domain for logging.
> 
> This patch gets error information from Xen hypervisor and convert
> Xen format error into Linux format mcelog. This logic is basically
> self-contained, not touching other kernel components.
> 
> By using tools like mcelog tool users could read specific error information,
> like what they did under native Linux.
> 
> To test follow directions outlined in Documentation/acpi/apei/einj.txt
> 
> Signed-off-by: Ke, Liping <liping.ke@intel.com>
> Signed-off-by: Jiang, Yunhong <yunhong.jiang@intel.com>
> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
> Signed-off-by: Liu, Jinsong <jinsong.liu@intel.com>

Still no go, this is current linus with your patch applied. I'll look into it
later when there's time.

[    3.644961] initlevel:6=device, 250 registered initcalls
[    3.652666] BUG: unable to handle kernel NULL pointer dereference at 0000000000000048
[    3.661186] IP: [<ffffffff811ced67>] kobject_get+0x11/0x34
[    3.667018] PGD 0 
[    3.669409] Oops: 0000 [#1] SMP 
[    3.672988] CPU 21 
[    3.675436] Modules linked in:
[    3.678839] 
[    3.680710] Pid: 1, comm: swapper/0 Tainted: G        W    3.4.0+ #1 AMD
[    3.689103] RIP: 0010:[<ffffffff811ced67>]  [<ffffffff811ced67>] kobject_get+0x11/0x34
[    3.697665] RSP: 0000:ffff880425c67cd0  EFLAGS: 00010202
[    3.703322] RAX: ffff880425ff40b0 RBX: 0000000000000010 RCX: ffff880425c67c50
[    3.710801] RDX: ffff880425ff4000 RSI: ffff8808259c5380 RDI: 0000000000000010
[    3.718302] RBP: ffff880425c67ce0 R08: 00000000fffffffe R09: 00000000ffffffff
[    3.725780] R10: ffff8804a5c67e5f R11: 0000000000000000 R12: 0000000000000010
[    3.733258] R13: 00000000fffffffe R14: 000000000000cbf8 R15: 0000000000011ec0
[    3.740738] FS:  0000000000000000(0000) GS:ffff880c27cc0000(0000) knlGS:0000000000000000
[    3.749472] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[    3.755564] CR2: 0000000000000048 CR3: 0000000001a0b000 CR4: 00000000000007e0
[    3.763044] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[    3.770549] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[    3.778026] Process swapper/0 (pid: 1, threadinfo ffff880425c66000, task ffff880425c78000)
[    3.786934] Stack:
[    3.789326]  ffff880425c67d20 ffff8808259c5380 ffff880425c67d40 ffffffff811cedeb
[    3.797368]  ffff880425c67d70 ffff880425c67da0 ffff8808259c5380 ffff8808259c5380
[    3.805411]  0000000000000000 ffff8808259c5380 0000000000000010 0000000000000000
[    3.813453] Call Trace:
[    3.816253]  [<ffffffff811cedeb>] kobject_add_internal+0x61/0x249
[    3.822693]  [<ffffffff811cf3ca>] kobject_add+0x91/0xa2
[    3.828290]  [<ffffffff811cf5a9>] kobject_create_and_add+0x37/0x68
[    3.834821]  [<ffffffff8144b91a>] threshold_create_device+0x1e5/0x342
[    3.841633]  [<ffffffff814549c5>] ? mutex_lock+0x16/0x37
[    3.847295]  [<ffffffff81031894>] ? cpu_maps_update_done+0x15/0x2d
[    3.853824]  [<ffffffff81ad0b0e>] threshold_init_device+0x1b/0x4f
[    3.860265]  [<ffffffff81ad0af3>] ? severities_debugfs_init+0x3b/0x3b
[    3.867054]  [<ffffffff810002f9>] do_one_initcall+0x7f/0x136
[    3.873062]  [<ffffffff81ac8bca>] kernel_init+0x165/0x1fd
[    3.878807]  [<ffffffff81ac8495>] ? loglevel+0x31/0x31
[    3.884321]  [<ffffffff8145e8d4>] kernel_thread_helper+0x4/0x10
[    3.890590]  [<ffffffff81456d86>] ? retint_restore_args+0xe/0xe
[    3.896885]  [<ffffffff81ac8a65>] ? start_kernel+0x2ee/0x2ee
[    3.902893]  [<ffffffff8145e8d0>] ? gs_change+0xb/0xb
[    3.908322] Code: aa 81 31 c0 e8 ac 90 01 00 4c 89 f7 e8 c5 42 f2 ff 5b 41 5c 41 5d 41 5e c9 c3 55 48 89 e5 53 48 89 fb 48 83 ec 08 48 85 ff 74 1c <8b> 47 38 85 c0 75 11 be 29 00 00 00 48 c7 c7 16 87 79 81 e8 95 
[    3.928115] RIP  [<ffffffff811ced67>] kobject_get+0x11/0x34
[    3.934032]  RSP <ffff880425c67cd0>
[    3.937870] CR2: 0000000000000048
[    3.941548] ---[ end trace 4eaa2a86a8e2da23 ]---
[    3.946581] Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000009
[    3.946581] 

-- 
Regards/Gruss,
Boris.

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