Re: [uml-devel] Re: Bug#224431: user-mode-linux: Hangs

[Matt Z. <md...@de...>]

On Thu, Dec 18, 2003 at 08:47:56PM -0500, Jeff Dike wrote:

> On Thu, Dec 18, 2003 at 04:29:49PM -0800, Matt Zimmerman wrote:
> > Apparently, tt mode is broken.  I use skas, which is working fine in
> > 2.4.22-7um-1, but I can reproduce your failure with mode=tt.
> 
> Hmmm, I can't.  It seems fine here.
> 
> Can you run it with 'debug' and get a stack trace from the hang?

Unfortunately, unstable recently received gdb 6.0, and 'debug' no longer
works.

GNU gdb 6.0-debian
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GDB is free software, covered by the GNU General Public License, and you are
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This GDB was configured as "i386-linux"...(no debugging symbols found)...
[hangs here indefinitely; gdb is suspended]
mdz      15970  0.0  0.4  5956 2576 pts/12   S    18:19   0:00 gdb --command /tm
mdz      15971  0.0  0.4  5956 2576 pts/12   T    18:19   0:00 gdb --command /tm

sending a SIGCONT to the suspended gdb process results in:

0xa01502b1 in ?? ()
/tmp/gdb_init-cJnGax:2: Error in sourced command file:
No symbol table is loaded.  Use the "file" command.
(gdb) 

(line 2 of the sourced command file is 'b panic')

It still seems to work to run UML inside gdb manually, though.  Here's the
backtrace:

(gdb) bt
#0  0xa016619d in waitpid ()
    at /space/tmp/mdz/debian/work/user-mode-linux/user-mode-linux-2.4.22-7um/kernel-source-2.4.22/include/linux/proc_fs.h:158
#1  0x00005261 in ?? ()
#2  0xa00c17b0 in tracer (init_proc=0xa00c03b0 <start_kernel_proc>, 
    sp=0xa01f3ffc) at tracer.c:236
#3  0xa00c04de in start_uml_tt () at process_kern.c:500
#4  0xa00bebc5 in linux_main (argc=7, argv=0xbffff684) at um_arch.c:387
#5  0xa000d3c1 in main (argc=7, argv=0xbffff684, envp=0xbffff6a4)
    at arch/um/main.c:146

In my case, the host kernel is 2.4.21 with skas3.

-- 
 - mdz