On 11/15/06, Seongsu Lee <senux@xxxxxxxxx> wrote:
Hello, I am a kernel newbie. I am playing with MTD on a embedded box. I got follow kernel oops messages after rebooting with various patches I made. I used gdb in debuging applications written in C in user land. How can I debug error in kernel? Any comments would be appreciated.
For kernel debugging you can use kdb or kgdb (search google for them). Kgdb debugs in terms of C-code and works as remote debugging tool while kdb debug in assembly and runs on local system.
Unable to handle kernel NULL pointer dereference at virtual address 00000000 pgd = c0004000 [00000000] *pgd=00000000 Internal error: Oops: 8f5 [#1] Modules linked in: CPU: 0 pc : [<c3da5014>] lr : [<c3da3c19>] Not tainted sp : c036df7c ip : c036df7c fp : c036dfb0 r10: c036df80 r9 : 00000001 r8 : c02a550c r7 : 00000000 r6 : c3da3000 r5 : c3da3198 r4 : 00000000 r3 : 00000000 r2 : 00000000 r1 : 00000090 r0 : 00000000 Flags: nZcv IRQs on FIQs on Mode SVC_32 Segment kernel Control: 397F Table: A0004000 DAC: 00000017 Process swapper (pid: 1, stack limit = 0xc036c1a4) Stack: (0xc036df7c to 0xc036e000) df60: 4f600000 df80: 00000000 00000000 c3da3000 c3da3000 c02a550c c3da3198 c02a550c 00000000 dfa0: 00000000 c036dfd4 c036dfb4 c0018c3c c0183508 c036c000 c001e92c 00000001 dfc0: c001e984 00000000 c036dff4 c036dfd8 c00230e4 c0018b30 00000000 00000000 dfe0: 00000000 00000000 00000000 c036dff8 c003b5c0 c002306c 20746f6f 6974706f Backtrace: Function entered at [<c01834fc>] from [<c0018c3c>] Function entered at [<c0018b24>] from [<c00230e4>] r8 = 00000000 r7 = C001E984 r6 = 00000001 r5 = C001E92C r4 = C036C000 Function entered at [<c0023060>] from [<c003b5c0>] r7 = 00000000 r6 = 00000000 r5 = 00000000 r4 = 00000000 Code: 00381013 00382013 00383013 00384013 (00385013) <0>Kernel panic - not syncing: Attempted to kill init!
For tracing oops from kernel, take a look at text-document oops-tracing.txt in kernel's Documentation directory (http://lxr.free-electrons.com/source/Documentation/oops-tracing.txt) -- Fawad Lateef -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
