On Fri, 5 Oct 2007 13:25:43 +0100 Ralf Baechle <ralf@xxxxxxxxxxxxxx> wrote:
> On Thu, Oct 04, 2007 at 02:49:13PM +0200, Giuseppe Sacco wrote:
>
> > Hi, while testing the latest kernel on SGI O2 I got may kernel bugs like
> > this:
[...]
> Very interesting. Can you describe me your setup or maybe even come up
> with a test case for this?
I may reproduce it without problems. The failing command is "ps aux". Once the command starts, the kernel log the bug and the command stay blocked: no shell prompt, no control-c working. Since the ps command does not work, I cannot check the prosess status :-)
This is a new log:
Code: 0002127a 00021000 30420001 <00028036> 8f820024 00052b3a 24420001 af820024 3c0236db
Kernel bug detected[#2]:
Cpu 0
$ 0 : 0000000000000000 ffffffff804a0000 0000000000000001 0000000000002f18
$ 4 : 980000000101cff8 000000007f94bf18 000000007f94bf18 6800000000000000
$ 8 : 0000000000000849 000000007f94bf18 980000000461bd68 980000000461bd60
$12 : 0000000000000010 ffffffff80000008 ffffffff800a3810 0000000000000000
$16 : 980000000101cff8 98000000035a3dd0 000000000000000e 000000007f94bf18
$20 : 98000000005d4048 9800000000506360 980000000461bd68 980000000461bd60
$24 : 0000000000000000 000000002abcc580
$28 : 9800000004618000 980000000461bcd0 0000000000000000 ffffffff8001da30
Hi : 00000000000018db
Lo : 0000000000000849
epc : ffffffff8001f1e0 kmap_coherent+0x10/0x128 Tainted: G D
ra : ffffffff8001da30 __flush_anon_page+0x90/0xc0
Status: 9001fce3 KX SX UX KERNEL EXL IE
Cause : 00000034
PrId : 00002321
Modules linked in: parport_pc lp parport ppp_deflate zlib_deflate bsd_comp ppp_async crc_ccitt ip_tables x_table
s ipv6 ppp_generic slhc dm_snapshot dm_mirror dm_mod ehci_hcd ohci_hcd r8169 usbcore sg evdev
Process pidof (pid: 26867, threadinfo=9800000004618000, task=9800000001ea4cc8)
Stack : ffffffff80089844 ffffffff80089424 0000000000000010 0000000000000000
0000000000000001 980000000461bd68 980000000461bd60 0000000000000000
9800000000506360 000000007f94bf18 9800000005dfb000 000000000000000f
9800000000506360 0000000000000000 98000000005d4048 980000000461bd68
9800000000000000 ffffffff80089a0c 0000000000000000 980000000101cff8
98000000005063c0 9800000005dfb000 9800000000506360 9800000005dfb000
000000000000000f 0000000000000000 98000000005d4048 980000000461be88
0000000000001000 000000007ff77c40 000000007ff77b40 ffffffff800f82f8
9800000005dfb000 98000000005d4048 fffffffffffffff4 98000000078516d8
0000000000000400 980000000461be88 000000002aac0000 ffffffff800faaec
...
Call Trace:
[<ffffffff8001f1e0>] kmap_coherent+0x10/0x128
[<ffffffff8001da30>] __flush_anon_page+0x90/0xc0
[<ffffffff80089844>] get_user_pages+0x49c/0x538
[<ffffffff80089a0c>] access_process_vm+0x12c/0x228
[<ffffffff800f82f8>] proc_pid_cmdline+0xa8/0x170
[<ffffffff800faaec>] proc_info_read+0x13c/0x180
[<ffffffff800a33b0>] vfs_read+0xf0/0x190
[<ffffffff800a385c>] sys_read+0x4c/0x90
[<ffffffff8001c674>] handle_sys+0x134/0x150
Code: 0002127a 00021000 30420001 <00028036> 8f820024 00052b3a 24420001 af820024 3c0236db
In order to collect more information, I tried "strace ps aux". The last lines printed are:
stat("/proc/313", {st_mode=S_IFDIR|0555, st_size=0, ...}) = 0
open("/proc/313/stat", O_RDONLY) = 6
read(6, "313 (kjournald) S 2 0 0 0 -1 328"..., 1023) = 157
close(6) = 0
open("/proc/313/status", O_RDONLY) = 6
read(6, "Name:\tkjournald\nState:\tS (sleepi"..., 1023) = 489
close(6) = 0
open("/proc/313/cmdline", O_RDONLY) = 6
read(6, "", 2047) = 0
close(6) = 0
stat64(0x2aca5318, 0x7fd6e228) = 0
write(1, "root 313 0.0 0.0 0 "..., 77root 313 0.0 0.0 0 0 ? S< Oct05 0:15 [kjournald]
) = 77
stat("/proc/422", {st_mode=S_IFDIR|0555, st_size=0, ...}) = 0
open("/proc/422/stat", O_RDONLY) = 6
read(6, "422 (udevd) D 1 422 422 0 -1 420"..., 1023) = 217
close(6) = 0
open("/proc/422/status", O_RDONLY) = 6
read(6, "Name:\tudevd\nState:\tD (disk sleep"..., 1023) = 677
close(6) = 0
open("/proc/422/cmdline", O_RDONLY) = 6
