Re: jprobe bug?

[Martin Hunt <hunt at redhat dot com>]

> To avoid having to mess with the various address I converted the example 
> back to a dtr script. I have attached the script to this email. The 
> script seemed to install okay. Does the address used in the module look 
> okay? I don't have a version of that kernel built.

I started with a dtr script like the one you attached.  It causes the
crash too. Then I tried just the basic C code I sent and it still
happened.

I've been running more tests this morning. It looks like you must have 2
CPUs (or 1 with hyperthreading enabled) and run the SMP kernel to
reproduce.

CPU           kernel   bug?
------------------------
Xeon/EM64T    UP       NO
2 Xeon/EM64T  SMP      YES
P4/HT         UP       NO
P4/HT         SMP      YES
P4/NoHT       SMP      NO

I'm using both 2.6.10-1.741_FC3 and 2.6.10-1.753_FC3.  problems appear
in both.

Ouch! My P4 box (hyperthreading with SMP kernel) just lost vertical sync
and crashed hard.

The easiest method to reproduce is to run and exit Firefox a couple of
times.  I've never had it run twice without hanging.  Keep trying and
your system should crash.

Most dumps don't look useful.  This one (from my P4 test system) might
be.

----

Jan 31 13:57:53 dragon kernel: Unable to handle kernel paging request
at 
virtual address 002031d3
Jan 31 13:57:53 dragon kernel:  printing eip:
Jan 31 13:57:53 dragon kernel: e8d36280
Jan 31 13:57:53 dragon kernel: *pde = 35da5001
Jan 31 13:57:53 dragon kernel: Oops: 0002 [#1]
Jan 31 13:57:53 dragon kernel: SMP
Jan 31 13:57:53 dragon kernel: Modules linked in: dtr(U) parport_pc lp 
parport autofs4 sunrpc dm_mod video button battery ac nvidia(U) md5
ipv6 
ohci1394 ieee1394 uhci_hcd ehci_hcd hw_random i2c_i801 i2c_core 
emu10k1_gp gameport snd_emu10k1 snd_rawmidi snd_seq_device 
snd_ac97_codec snd_pcm_oss snd_mixer_oss snd_pcm snd_timer 
snd_page_alloc snd_util_mem snd_hwdep snd soundcore e1000 ext3 jbd 
ata_piix libata sd_mod scsi_mod
Jan 31 13:57:53 dragon kernel: CPU:    1
Jan 31 13:57:53 dragon kernel: EIP:    0060:[<e8d36280>]    Tainted: 
P      VLI
Jan 31 13:57:53 dragon kernel: EFLAGS: 00213282   (2.6.10-1.741_FC3smp)
Jan 31 13:57:53 dragon kernel: EIP is at 0xe8d36280
Jan 31 13:57:53 dragon kernel: eax: 00000000   ebx: eba442e0   ecx: 
edfcf318   edx: 00203200
Jan 31 13:57:53 dragon kernel: esi: eba44000   edi: c0160f77   ebp: 
00000000   esp: f5a08f00
Jan 31 13:57:53 dragon kernel: ds: 007b   es: 007b   ss: 0068
Jan 31 13:57:54 dragon kernel: Process X (pid: 4988,
threadinfo=f5a08000 
task=f4c73530)
Jan 31 13:57:54 dragon kernel: Stack: 00000001 c0161367 00000000 
Jan 31 13:57:54 dragon kernel: 001fffff 00000000 00000000 00000000
Jan 31 13:57:54 dragon kernel:        00000015 001fffff f73821cc 
f73821ac f738218c f738222c f738220c f73821ec
Jan 31 13:57:54 dragon gconfd (hunt-5320): Received signal 15, shutting 
down cleanly
Jan 31 13:57:54 dragon kernel:        000dc2f3 00000055 00000000 
f5a08f8c f5a08f90 00000055 c0160f95 eba44000
Jan 31 13:57:54 dragon kernel: Call Trace:
Jan 31 13:57:54 dragon kernel:  [<c0161367>] do_select+0x298/0x2ac
Jan 31 13:57:54 dragon gconfd (hunt-5320): Exiting
Jan 31 13:57:54 dragon kernel:  [<c0160f95>] __pollwait+0x0/0x95
Jan 31 13:57:54 dragon kernel:  [<c016169b>] sys_select+0x30d/0x49e
Jan 31 13:57:54 dragon kernel:  [<c012194c>] sys_gettimeofday+0x25/0x55
Jan 31 13:57:54 dragon kernel:  [<c0103c97>] syscall_call+0x7/0xb