Re: [uml-user] Kernel stack overflow panic

[Alexander B. <ab...@li...>]

Hi,

...on Thu, Sep 09, 2004 at 11:56:18PM -0400, Jeff Dike wrote:

 > wo...@ka... said:
 > > The uml kernel is hosted on a 2.4 kernel with skas patch and the uml
 > > kernel is 2.4.24 with the um1 patch applied. 
 > Can you try this with the latest UML?  It seems to work fine for me.  The
 > most interesting thing that happened was this (at 108M on a 128M UML):
 > 	Segmentation fault

Can't make an 2.4.26um3 - based guest crash either 
with this.

I do see some "Kernel stack overflow" panics, though - 
just not since I attached a gdb to the affected guest, 
so all I currently have is a truncated oops to which 
ksymoops says the following (this is 2.4.27 + um3 with 
skas + sysemu from the patches page):

# ksymoops -KLOM -v ../linux-2.4.27um3-20040824 uml4.log
ksymoops 2.4.9 on i686 2.4.27.  Options used
     -v ../linux-2.4.27um3-20040824 (specified)
     -K (specified)
     -L (specified)
     -O (specified)
     -M (specified)

Kernel panic: Kernel stack overflow
EIP: 0023:[<0a285000>] CPU: 0 Not tainted ESP: 002b:bfffe504 EFLAGS: 00210282
Using defaults from ksymoops -t elf32-i386 -a i386
EAX: 00000002 EBX: 0bb4b974 ECX: 0bb58fd4 EDX: bfffe538
ESI: 090fb4c4 EDI: 0bba8e3c EBP: bfffe524 DS: 002b ES: 002b
Warning (Oops_set_regs): garbage 'DS: 002b ES: 002b' at end of register line ign
ored
Call Trace: [<08106790>] [<080f522f>] [<0806331d>] [<08059248>] [<080f4608>]
  [<080f4653>] [<080f79d0>] [<080f4756>] [<080f700a>] [<080f0635>] [<080f0770>]
  [<080f6aa7>] [<080f37a9>] [<080f706a>] [<080f5fb4>] [<080f63ca>] [<080f6cb4>]
   
Warning (Oops_read): Code line not seen, dumping what data is available

>>EIP; 0a285000 <END_OF_CODE+20922f8/????>   <=====

Trace; 08106790 <handle_sysrq+50/70>
Trace; 080f522f <panic_exit+2f/50>
Trace; 0806331d <notifier_call_chain+2d/50>
Trace; 08059248 <panic+a8/130>
Trace; 080f4608 <handle_page_fault+228/230>
Trace; 080f4653 <check_remapped_addr+23/90>
Trace; 080f79d0 <copy_chunk_to_user+0/40>
Trace; 080f4756 <segv+96/1c0>
Trace; 080f700a <execute_syscall_skas+aa/b0>
Trace; 080f0635 <external_pid+15/30>
Trace; 080f0770 <set_current+20/40>
Trace; 080f6aa7 <_switch_to_skas+47/90>
Trace; 080f37a9 <record_syscall_start+59/70>
Trace; 080f706a <handle_syscall+5a/80>
Trace; 080f5fb4 <handle_segv+54/80>
Trace; 080f63ca <userspace+fa/170>
Trace; 080f6cb4 <fork_handler+84/a0>


2 warnings issued.  Results may not be reliable.


Alex.