<=2.4.17 deadlock (RedHat 7.2, SMP)

<=2.4.17 deadlock (RedHat 7.2, SMP)

[Frank van Maarseveen]

The problem occurs only when I disconnect a PPP dialup to an ISP. It
results in a box which only listens to alt-sysrq or a power cycle. The
userland setup is a bit complicated (two pppd instances, a zebra routing
daemon) but below there should be a clue about the cause.  This is all
on a RedHat 7.2 distro running on a dual PIII box. My brain decoded the
following JPEG picture I took from the screen after typing alt-sysrq-p
3 times:

Pid: 5613, comm                 pppd
EIP: 0010: [<c0403068>] CPU: 1 EFLAGS 00000286  not tainted
Call Trace: c0273cae c028ee04 c0293ac8 c0155879 c013f063
   c0150bc6 c028eac8 c01076cb

Pid: 5613, comm                 pppd
EIP: 0010: [<c040306f>] CPU: 1 EFLAGS 00000286  not tainted 
Call Trace: c0273cae c028ee04 c0293ac8 c0155879 c013f063
   c0150bc6 c028eac8 c01076cb

Pid: 18, comm                   kjournald
EIP: 0010: [<c03fca5b>] CPU: 0 EFLAGS 00000286  not tainted
Call Trace: c02ad897 c011f1ea c0140af5 c0179dde c011560c
   c017ca4d c017c7e0 c010590f

cat /proc/version says:
Linux version 2.4.17-b65 (fvm@iapetus.localdomain) (gcc version egcs-2.91.66 19990314/Linux (egcs-1.1.2 release)) #1 SMP Sun Dec 23 22:16:27 CET 2001

ksymoops says:
ksymoops 2.4.1 on i686 2.4.17-b65.  Options used
     -V (default)
     -k /proc/ksyms (default)
     -l /proc/modules (default)
     -o /lib/modules/2.4.17-b65/ (default)
     -m /boot/System.map-2.4.17-b65 (default)

Warning: You did not tell me where to find symbol information.  I will
assume that the log matches the kernel and modules that are running
right now and I'll use the default options above for symbol resolution.
If the current kernel and/or modules do not match the log, you can get
more accurate output by telling me the kernel version and where to find
map, modules, ksyms etc.  ksymoops -h explains the options.

No modules in ksyms, skipping objects
Warning (read_lsmod): no symbols in lsmod, is /proc/modules a valid lsmod file?
EIP: 0010: [<c0403068>] CPU: 1 EFLAGS 00000286  not tainted
Using defaults from ksymoops -t elf32-i386 -a i386
Call Trace: c0273cae c028ee04 c0293ac8 c0155879 c013f063
   c0150bc6 c028eac8 c01076cb
EIP: 0010: [<c040306f>] CPU: 1 EFLAGS 00000286  not tainted
Call Trace: c0273cae c028ee04 c0293ac8 c0155879 c013f063
   c0150bc6 c028eac8 c01076cb
EIP: 0010: [<c03fca5b>] CPU: 0 EFLAGS 00000286  not tainted
Call Trace: c02ad897 c011f1ea c0140af5 c0179dde c011560c
   c017ca4d c017c7e0 c010590f
Warning (Oops_read): Code line not seen, dumping what data is available

>>EIP; c0403068 <stext_lock+6c30/e9ac>   <=====
Trace; c0273cae <rs_wait_until_sent+b6/c4>
Trace; c028ee04 <ppp_ioctl+33c/d84>
Trace; c0293ac8 <ppp_destroy_channel+1bc/1c4>
Trace; c0155879 <dput+19/214>
Trace; c013f063 <filp_close+133/140>
>>EIP; c040306f <stext_lock+6c37/e9ac>   <=====
Trace; c0273cae <rs_wait_until_sent+b6/c4>
Trace; c028ee04 <ppp_ioctl+33c/d84>
Trace; c0293ac8 <ppp_destroy_channel+1bc/1c4>
Trace; c0155879 <dput+19/214>
Trace; c013f063 <filp_close+133/140>
>>EIP; c03fca5b <stext_lock+623/e9ac>   <=====
Trace; c02ad897 <do_ide_request+f/14>
Trace; c011f1ea <__run_task_queue+d2/e0>
Trace; c0140af5 <__wait_on_buffer+55/9c>
Trace; c0179dde <journal_commit_transaction+114a/181c>
Trace; c011560c <schedule+640/818>


3 warnings issued.  Results may not be reliable.

-- 
Frank

<=2.4.17 deadlock (RedHat 7.2, SMP, ext3 related?) (2)

[Frank van Maarseveen]

Below a second case, again it occured right at the moment a PPP
connection was terminated. For some unknown reason it seems to occur
frequently enough now for doing some experimenting. Tell me if more info
is needed. This is the same kernel as before. When the problem first
emerged some weeks ago after installing RedHat 7.2 I switched to kgcc
(gcc version egcs-2.91.66 19990314/Linux (egcs-1.1.2 release)) instead
of gcc 2.96 but it didn't make a difference.

Following two alt-sysrq-p have been decoded from a JPEG image I took from
the screen. Even alt-sysrq-l leaves most processes intact according to
alt-sysrq-t so to me it looks like a genuine deadlock:

Pid: 4465, comm:	hotplug
EIP: 0010:[<c03fe0ba>] CPU: 0 EFLAGS 00000286	not tainted
Call Trace: c0140134 c013eba2 c013eab2 c013ee23 c01076cb

Pid: 2930, comm:	pppd
EIP: 0010:[<c0403068>] CPU: 1 EFLAGS 00000286	not tainted
Call Trace: c016d320 c028ee04 c0159e01 c0156e68 c013f063 c0150bc6 c028eac8 c01076cb

Now ksymoops at work:
ksymoops 2.4.1 on i686 2.4.17-b65.  Options used
     -V (default)
     -k /proc/ksyms (default)
     -l /proc/modules (default)
     -o /lib/modules/2.4.17-b65/ (default)
     -m /boot/System.map-2.4.17-b65 (default)

Warning: You did not tell me where to find symbol information.  I will
assume that the log matches the kernel and modules that are running
right now and I'll use the default options above for symbol resolution.
If the current kernel and/or modules do not match the log, you can get
more accurate output by telling me the kernel version and where to find
map, modules, ksyms etc.  ksymoops -h explains the options.

No modules in ksyms, skipping objects
Warning (read_lsmod): no symbols in lsmod, is /proc/modules a valid lsmod file?
EIP: 0010:[<c03fe0ba>] CPU: 0 EFLAGS 00000286   not tainted
Using defaults from ksymoops -t elf32-i386 -a i386
Call Trace: c0140134 c013eba2 c013eab2 c013ee23 c01076cb
EIP: 0010:[<c0403068>] CPU: 1 EFLAGS 00000286   not tainted
Call Trace: c016d320 c028ee04 c0159e01 c0156e68 c013f063 c0150bc6 c028eac8 c01076cb
Warning (Oops_read): Code line not seen, dumping what data is available

>>EIP; c03fe0ba <stext_lock+1c82/e9ac>   <=====
Trace; c0140134 <chrdev_open+28/124>
Trace; c013eba2 <dentry_open+e6/194>
Trace; c013eab2 <filp_open+52/5c>
Trace; c013ee23 <sys_open+4b/140>
Trace; c01076cb <system_call+33/38>
>>EIP; c0403068 <stext_lock+6c30/e9ac>   <=====
Trace; c016d320 <ext3_delete_inode+0/270>
Trace; c028ee04 <ppp_ioctl+33c/d84>
Trace; c0159e01 <iput+2c5/2f0>
Trace; c0156e68 <d_delete+dc/20c>
Trace; c013f063 <filp_close+133/140>
Trace; c0150bc6 <sys_ioctl+24a/2e4>
Trace; c028eac8 <ppp_ioctl+0/d84>
Trace; c01076cb <system_call+33/38>


3 warnings issued.  Results may not be reliable.

-- 
Frank