Panic with SLAB debugging enabled

From: Pavel Roskin (
Date: 2002-06-27 23:11:05 UTC


The CVS version of HostAP causes a kernel oops at startup (poosibly while bringing the interface up). The kernel is 2.4.19-rc1 with CONFIG_DEBUG_SLAB defined in .config (i.e. with malloc debugger).

I don't have time to debug it today, I just hope somebody will say Oops and fix it before I find time to look at it. By the way, it's a very good idea to have CONFIG_DEBUG_SLAB enabled for anybody doing kernel development.

kernel BUG at slab.c:1443!
invalid operand: 0000
CPU: 0
EIP: 0010:[<c0129a12>] Not tainted Using defaults from ksymoops -t elf32-i386 -a i386 EFLAGS: 00010093
eax: 170fc200 ebx: c100001c ecx: c115d0a0 edx: c6e56ec0 esi: c6e56000 edi: 0012f6c8 ebp: c6675ef0 esp: c6675ed4 ds: 0018 es: 0018 ss: 0018
Process iwconfig (pid: 748, stackpage=c6675000) Stack: 00000000 c6e56e98 00000286 c115d0a0 00000000 c6e56e9c c0220d64 c6675f3c

       c01de13e c6e56e9c c6675fb4 c01109e4 c72faa34 c6607afc c6675f54 c8a9b054 
       c11f5a00 c6675f54 00008b1b c6675f54 c6675f74 c6675f34 c01d71ac 00000000 
Call Trace: [<c01de13e>] [<c01109e4>] [<c8a9b054>] [<c01d71ac>] [<c01d8c0b>]

   [<c01d0dae>] [<c013d117>] [<c0108be3>] Code: 0f 0b a3 05 d7 6c 22 c0 8b 41 1c eb 07 90 8b 55 f0 8b 42 1c

>>EIP; c0129a12 <kfree+182/280> <=====

Trace; c01de13e <wireless_process_ioctl+33e/5d0>
Trace; c01109e4 <do_page_fault+1c4/544>
Trace; c8a9b054 <[hostap_cs]prism2_ioctl_giwessid+0/ac>
Trace; c01d71ac <dev_get+c/20>
Trace; c01d8c0a <dev_ioctl+36a/3e0>
Trace; c01d0dae <sock_ioctl+1e/30>
Trace; c013d116 <sys_ioctl+1b6/1d0>
Trace; c0108be2 <system_call+32/40>

Code; c0129a12 <kfree+182/280>
00000000 <_EIP>:
Code; c0129a12 <kfree+182/280> <=====
   0:   0f 0b                     ud2a      <=====
Code;  c0129a14 <kfree+184/280>
   2:   a3 05 d7 6c 22            mov    %eax,0x226cd705
Code;  c0129a18 <kfree+188/280>
   7:   c0 8b 41 1c eb 07 90      rorb   $0x90,0x7eb1c41(%ebx)
Code;  c0129a20 <kfree+190/280>
   e:   8b 55 f0                  mov    0xfffffff0(%ebp),%edx
Code;  c0129a22 <kfree+192/280>
  11:   8b 42 1c                  mov    0x1c(%edx),%eax

Pavel Roskin

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