-----Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote: -----
>Try one more test: While the ws2500 program is running, make a copy
>of
>both the "async" and "registers" files in
>/sys/kernel/debug/usb/ohci/0000:00:02.0/. Then try to make a second
>copy after shutting down the program and causing it to hang.
Hmm this is really hard because the ws2500 just reads waetherdata when
started and then pipes it to a file. I have to be very very fast to copy
the async files.
But, i rebooted, launched gdb and set a breakpoint while teh progeam reads
some data.
(gdb) r
Starting program: /var/www/localhost/htdocs/ws2000/ws2500-1.7/ws2500
-p /dev/ttyWeather -n -t -i
Breakpoint 1, getData (ws2500Data=0x7ffff05c43c0, dcfInfo=0x7ffff05c4580,
ws2500Stat=0x7ffff05c4510) at ws2500.c:1298
1298 DEBUG1("start getData\n");
(gdb)
Then i tried to get the needed files:
Server ws2500-1.7 # mount -t debugfs none /sys/kernel/debug
Server ws2500-1.7 # cd /sys/kernel/debug
Server debug # cd usb/
devices ehci/ ohci/ usbmon/
Server debug # cd usb/ohci/0000\:00\:02.0/
Server 0000:00:02.0 # ls -al
total 0
drwxr-xr-x 2 root root 0 Nov 22 2010 .
drwxr-xr-x 4 root root 0 Nov 22 2010 ..
-r--r--r-- 1 root root 0 Nov 22 2010 async
-r--r--r-- 1 root root 0 Nov 22 2010 periodic
-r--r--r-- 1 root root 0 Nov 22 2010 registers
Server 0000:00:02.0 # cat async
Killed
Server 0000:00:02.0 # cat registers
Okay. I'm unable to get the contents of that file. The 'cat' locks up. I'm
not able to get into a new shell. No more processes will be launched. I can
input characters but nothing happens. No output on the log console, still
nothing. But it's reponding to ping over the network. Strange. I
experienced this with kernel 3.6.36 more often.
At least, i'm able to switch the console but i have to use the sysreq-key
to sync, remount readonly and reboot the whole system.
After the reboot i tried a second time, with nearly the same result. I
tried to cat async two times. *LOCK*. But i was fast enough to get the
dmesg output:
[ 146.618442] BUG: unable to handle kernel paging request at
ffff88018859efff
[ 146.618446] IP: [<ffffffff81253603>] vsnprintf+0xcb/0x42a
[ 146.618452] PGD 1a0a063 PUD 0
[ 146.618454] Oops: 0002 [#1] SMP
[ 146.618456] last sysfs
file: /sys/devices/pci0000:00/0000:00:10.0/0000:03:00.0/0000:04:03.0/resource
[ 146.618459] CPU 0
[ 146.618460] Modules linked in: vboxnetadp vboxnetflt vboxdrv w83791d
hwmon_vid ds3000 cx23885 cx2341x v4l2_common videodev v4l1_compat
v4l2_compat_ioctl32 videobuf_dma_sg videobuf_dvb dvb_core videobuf_core
ir_common btcx_risc tveeprom ir_core k10temp asus_atk0110 ftdi_sio
usbserial
[ 146.618472]
[ 146.618475] Pid: 6311, comm: cat Not tainted 2.6.34-gentoo-r12 #6
CROSSHAIR II FORMULA/System Product Name
[ 146.618477] RIP: 0010:[<ffffffff81253603>] [<ffffffff81253603>]
vsnprintf+0xcb/0x42a
[ 146.618481] RSP: 0018:ffff88008864dd28 EFLAGS: 00010002
[ 146.618482] RAX: 0000000000000005 RBX: ffff88008864dd88 RCX:
0000000000000001
[ 146.618484] RDX: ffffffff8182ac6a RSI: ffffffff8182ac6a RDI:
ffff88018859efff
[ 146.618486] RBP: ffff88008864dd78 R08: 0000000000000005 R09:
00000000000001fd
[ 146.618487] R10: 0000000000000005 R11: 0000000000000020 R12:
ffff88018859efff
[ 146.618489] R13: ffff88018859f000 R14: ffff88018859efff R15:
ffffffff8182ac6f
[ 146.618491] FS: 00007f5556aee6f0(0000) GS:ffff880001e00000(0000)
knlGS:0000000000000000
[ 146.618492] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[ 146.618494] CR2: ffff88018859efff CR3: 00000000885b3000 CR4:
00000000000006f0
[ 146.618495] DR0: 0000000000000000 DR1: 0000000000000000 DR2:
0000000000000000
[ 146.618497] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7:
0000000000000400
[ 146.618499] Process cat (pid: 6311, threadinfo ffff88008864c000, task
ffff880136f2eac0)
[ 146.618500] Stack:
[ 146.618501] ffffffff8182ac6a 0000000000000001 0000000000000000
00000000000080d0
[ 146.618504] <0> 0000000000000000 0000000000000001 ffff880005822108
0000000000000001
[ 146.618506] <0> ffff88018859efff ffffffff81815151 ffff88008864dde8
ffffffff812539f2
[ 146.618509] Call Trace:
[ 146.618512] [<ffffffff812539f2>] scnprintf+0x38/0x4b
[ 146.618515] [<ffffffff81386631>] show_list+0x196/0x1f8
[ 146.618518] [<ffffffff813866e5>] fill_async_buffer+0x52/0x6d
[ 146.618520] [<ffffffff81386a2c>] debug_output+0x56/0xa6
[ 146.618523] [<ffffffff81212b35>] ? security_file_permission+0x11/0x13
[ 146.618526] [<ffffffff810ddbb6>] vfs_read+0xa6/0x103
[ 146.618528] [<ffffffff810ddcc9>] sys_read+0x45/0x69
[ 146.618531] [<ffffffff8100296b>] system_call_fastpath+0x16/0x1b
[ 146.618532] Code: ce ff 24 cd 90 76 64 81 4d 39 ec 73 20 4c 89 ee 48 63
f8 44 89 e9 4c 29 e6 44 29 e1 48 39 f7 4c 89 e7 48 89 d6 0f 4e c8 48 63 c9
<f3> a4 4d 01 c4 e9 1c 03 00 00 8b 13 83 fa 2f 77 0d 89 d0 83 c2
[ 146.618549] RIP [<ffffffff81253603>] vsnprintf+0xcb/0x42a
[ 146.618552] RSP <ffff88008864dd28>
[ 146.618553] CR2: ffff88018859efff
[ 146.618555] ---[ end trace 40e07890eee9b1e2 ]---
Here is what lspci spits out, because in the log it says something like:
"last sysfs
file /sys/devices/pci0000:00/0000:00:10.0/0000:03:00.0/0000:04:03.0/resource".
Its the PCI bridge.
Server ~ # lspci -s 00:10.0 -v
00:10.0 PCI bridge: nVidia Corporation MCP78S [GeForce 8200] PCI Express
Bridge (rev a1) (prog-if 00 [Normal decode])
Flags: bus master, fast devsel, latency 0
Bus: primary=00, secondary=03, subordinate=07, sec-latency=0
I/O behind bridge: 0000a000-0000cfff
Memory behind bridge: fda00000-fdcfffff
Prefetchable memory behind bridge: 00000000fd700000-00000000fd9fffff
Capabilities: [40] Subsystem: ASUSTeK Computer Inc. Device 8332
Capabilities: [48] Power Management version 3
Capabilities: [50] Message Signalled Interrupts: Mask- 64bit+ Count=1/2
Enable+
Capabilities: [60] HyperTransport: MSI Mapping Enable+ Fixed-
Capabilities: [80] Express Root Port (Slot-), MSI 00
Kernel driver in use: pcieport
Server ~ # lspci -s 03:00.0 -v
03:00.0 PCI bridge: nVidia Corporation Device 05b1 (rev a2) (prog-if 00
[Normal decode])
Flags: bus master, fast devsel, latency 0
Bus: primary=03, secondary=04, subordinate=07, sec-latency=0
I/O behind bridge: 0000a000-0000cfff
Memory behind bridge: fda00000-fdcfffff
Prefetchable memory behind bridge: 00000000fd700000-00000000fd9fffff
Capabilities: [40] Power Management version 3
Capabilities: [60] Express Upstream Port, MSI 00
Capabilities: [a0] Subsystem: nVidia Corporation Device 0c19
Server ~ # lspci -s 04:03.0 -v
04:03.0 PCI bridge: nVidia Corporation Device 05b1 (rev a2) (prog-if 00
[Normal decode])
Flags: bus master, fast devsel, latency 0
Bus: primary=04, secondary=07, subordinate=07, sec-latency=0
I/O behind bridge: 0000a000-0000afff
Memory behind bridge: fda00000-fdafffff
Prefetchable memory behind bridge: 00000000fd700000-00000000fd7fffff
Capabilities: [40] Power Management version 3
Capabilities: [60] Express Downstream Port (Slot+), MSI 00
Looks like a kernel problem? Or a graphics card problem? (I use the
integrated graphics.) But a hang in scnprintf, what the hell...?
I'm really confused, now.
David
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