This teaches the i386 oops dumper to dump opcodes preceding and after the
offending EIP. Supporting code against ksymoops has been tested and produces
output like this:
ksymoops 2.4.8 on i686 2.5.65-mm2. Options used
-v /boot/vmlinux (specified)
-K (specified)
-L (specified)
-o /lib/modules/2.5.65-mm2/ (default)
-M (specified)
No modules in ksyms, skipping objects
Mar 18 23:37:08 vmm kernel: <1>Unable to handle kernel NULL pointer dereference at virtual address 00000000
Mar 18 23:37:08 vmm kernel: c014fcdc
Mar 18 23:37:08 vmm kernel: *pde = 00000000
Mar 18 23:37:08 vmm kernel: Oops: 0002 [#2]
Mar 18 23:37:08 vmm kernel: CPU: 1
Mar 18 23:37:08 vmm kernel: EIP: 0060:[<c014fcdc>] Not tainted
Using defaults from ksymoops -t elf32-i386 -a i386
Mar 18 23:37:08 vmm kernel: EFLAGS: 00010246 VLI
Mar 18 23:37:08 vmm kernel: eax: cd20ace0 ebx: fffffffe ecx: c17f3c08 edx: c17f3c18
Mar 18 23:37:08 vmm kernel: esi: fffffffe edi: cc427000 ebp: cc29dfbc esp: cc29dfa8
Mar 18 23:37:08 vmm kernel: ds: 007b es: 007b ss: 0068
Mar 18 23:37:08 vmm kernel: Stack: cffbd908 cc427000 4001020d 00000000 bfffeff0 cc29c000 c0109143 4001020d
Mar 18 23:37:08 vmm kernel: 00000000 00000003 00000000 bfffeff0 bfffef08 00000005 0000007b 0000007b
Mar 18 23:37:08 vmm kernel: 00000005 4000ef94 00000073 00000206 bfffee58 0000007b
Mar 18 23:37:08 vmm kernel: Call Trace:
Mar 18 23:37:08 vmm kernel: [<c0109143>] syscall_call+0x7/0xb
Mar 18 23:37:08 vmm kernel: Code: 35 89 da 89 f0 e8 51 ff ff ff 57 a1 30 9a 46 c0 50 e8 85 c8 fe ff b8 00 e0 ff ff 21 e0 8b 00 81 b8 e4 01 00 00 0e 27 00 00 75 07 <c6> 05 00 00 00 00 00 89 f0 eb 0b 89 f0 e8 ca fe ff ff 89 de eb
>>EIP; c014fcdc <sys_open+84/a4> <=====
>>eax; cd20ace0 <_end+cd82afc/3fb77d20>
>>ebx; fffffffe <TSS_ESP0_OFFSET+fa/????>
>>ecx; c17f3c08 <_end+136ba24/3fb77d20>
>>edx; c17f3c18 <_end+136ba34/3fb77d20>
>>esi; fffffffe <TSS_ESP0_OFFSET+fa/????>
>>edi; cc427000 <_end+bf9ee1c/3fb77d20>
>>ebp; cc29dfbc <_end+be15dd8/3fb77d20>
>>esp; cc29dfa8 <_end+be15dc4/3fb77d20>
Trace; c0109143 <syscall_call+7/b>
Code; c014fcb1 <sys_open+59/a4>
00000000 <_EIP>:
Code; c014fcb1 <sys_open+59/a4>
0: 35 89 da 89 f0 xor $0xf089da89,%eax
Code; c014fcb6 <sys_open+5e/a4>
5: e8 51 ff ff ff call ffffff5b <_EIP+0xffffff5b>
Code; c014fcbb <sys_open+63/a4>
a: 57 push %edi
Code; c014fcbc <sys_open+64/a4>
b: a1 30 9a 46 c0 mov 0xc0469a30,%eax
Code; c014fcc1 <sys_open+69/a4>
10: 50 push %eax
Code; c014fcc2 <sys_open+6a/a4>
11: e8 85 c8 fe ff call fffec89b <_EIP+0xfffec89b>
Code; c014fcc7 <sys_open+6f/a4>
16: b8 00 e0 ff ff mov $0xffffe000,%eax
Code; c014fccc <sys_open+74/a4>
1b: 21 e0 and %esp,%eax
Code; c014fcce <sys_open+76/a4>
1d: 8b 00 mov (%eax),%eax
Code; c014fcd0 <sys_open+78/a4>
1f: 81 b8 e4 01 00 00 0e cmpl $0x270e,0x1e4(%eax)
Code; c014fcd7 <sys_open+7f/a4>
26: 27 00 00
Code; c014fcda <sys_open+82/a4>
29: 75 07 jne 32 <_EIP+0x32>
Code; c014fcdc <sys_open+84/a4> <=====
2b: c6 05 00 00 00 00 00 movb $0x0,0x0 <=====
Code; c014fce3 <sys_open+8b/a4>
32: 89 f0 mov %esi,%eax
Code; c014fce5 <sys_open+8d/a4>
34: eb 0b jmp 41 <_EIP+0x41>
Code; c014fce7 <sys_open+8f/a4>
36: 89 f0 mov %esi,%eax
Code; c014fce9 <sys_open+91/a4>
38: e8 ca fe ff ff call ffffff07 <_EIP+0xffffff07>
Code; c014fcee <sys_open+96/a4>
3d: 89 de mov %ebx,%esi
Code; c014fcf0 <sys_open+98/a4>
3f: eb .byte 0xeb
arch/i386/kernel/traps.c | 21 ++++++++++++---------
1 files changed, 12 insertions(+), 9 deletions(-)
diff -puN arch/i386/kernel/traps.c~oops-dump-preceding-code arch/i386/kernel/traps.c
--- 25/arch/i386/kernel/traps.c~oops-dump-preceding-code 2003-03-18 23:55:58.000000000 -0800
+++ 25-akpm/arch/i386/kernel/traps.c 2003-03-18 23:55:58.000000000 -0800
@@ -186,8 +186,9 @@ void show_registers(struct pt_regs *regs
ss = regs->xss & 0xffff;
}
print_modules();
- printk("CPU: %d\nEIP: %04x:[<%08lx>] %s\nEFLAGS: %08lx\n",
- smp_processor_id(), 0xffff & regs->xcs, regs->eip, print_tainted(), regs->eflags);
+ printk("CPU: %d\nEIP: %04x:[<%08lx>] %s\nEFLAGS: %08lx VLI\n",
+ smp_processor_id(), 0xffff & regs->xcs,
+ regs->eip, print_tainted(), regs->eflags);
print_symbol("EIP is at %s\n", regs->eip);
printk("eax: %08lx ebx: %08lx ecx: %08lx edx: %08lx\n",
@@ -203,23 +204,25 @@ void show_registers(struct pt_regs *regs
* time of the fault..
*/
if (in_kernel) {
+ u8 *eip;
printk("\nStack: ");
show_stack((unsigned long*)esp);
printk("Code: ");
- if(regs->eip < PAGE_OFFSET)
- goto bad;
- for(i=0;i<20;i++)
- {
+ eip = (u8 *)regs->eip - 43;
+ for (i = 0; i < 64; i++, eip++) {
unsigned char c;
- if(__get_user(c, &((unsigned char*)regs->eip)[i])) {
-bad:
+
+ if (eip < (u8 *)PAGE_OFFSET || __get_user(c, eip)) {
printk(" Bad EIP value.");
break;
}
- printk("%02x ", c);
+ if (eip == (u8 *)regs->eip)
+ printk("<%02x> ", c);
+ else
+ printk("%02x ", c);
}
}
printk("\n");
_