LddDebuggingOopses < Training2

%SECTION0{name=LddDebuggingOopses}% Debugging Oopses

   * occurs when driver accesses invalid pointer or NULL pointer

   * MMU signals page fault but page is invalid: *oops* message is
     printed. (_arch/*/kernel/traps.c_)

<verbatim>
Unable to handle kernel paging request for data at address 0x00000000
Faulting instruction address: 0xd107c0c8
Oops: Kernel access of bad area, sig: 11 [#1]
Sequoia
Modules linked in: faulty chrdrv [last unloaded: faulty]
NIP: d107c0c8 LR: c0072834 CTR: 0fe368a4
REGS: cf9cfe40 TRAP: 0300   Not tainted  (2.6.25-rc2-00102-g0640ebb)
MSR: 00029000 <EE,ME>  CR: 48242028  XER: 00000007
DEAR: 00000000, ESR: 00800000
TASK = cfa5d000[950] 'bash' THREAD: cf9ce000
GPR00: d107c0c0 cf9cfef0 cfa5d000 00000000 4801f000 00000004 cf9cff20 00000000 
GPR08: 00000000 00000000 00000004 00000000 00000004 100fd4b8 00000000 00000000 
GPR16: 10125058 1009e4f0 100f0000 100f7998 00000000 00000000 101219a8 00000000 
GPR24: 00000001 100ac1ac bfaf4918 cf9cff20 4801f000 cfa2ba00 0ff448a8 00000004 
NIP [d107c0c8] faulty_write+0x8/0x10 [faulty]
LR [c0072834] vfs_write+0xcc/0x16c
Call Trace:
[cf9cfef0] [c0072804] vfs_write+0x9c/0x16c (unreliable)
[cf9cff10] [c0072ec8] sys_write+0x4c/0x90
[cf9cff40] [c000cf20] ret_from_syscall+0x0/0x3c
Instruction dump:
38810008 7cbdf850 480000d1 7c7d1a14 4bffffc4 7fc3f378 38810008 7fe5fb78 
480000b9 4bffffb0 39200000 38600000 <91290000> 4e800020 7c0802a6 9421fff0 
---[ end trace 4d8ed6ffb404bf6e ]---
</verbatim>
5.4.1. Debugging with printk		1. Denx Training Topics		5.4.3. Debugging with Hardware Debuggers
Prev		Home		Next