Re: Serial related oops

From: Jose Goncalves
Date: Wed Feb 21 2007 - 09:56:25 EST

Jose Goncalves wrote:
> New devolpments.
> I have upgraded to, applied a patch sent by Frederik that
> removed the changed made in and
> activated some more kernel debug, i.e., CONFIG_KALLSYMS_ALL,
> (thanks to vda for pointing me to the right doc.).
> At first it seemed to work fine, but after some days of continuous
> running I've got another kernel Oops!
> I attach the dmesg output and the assembly dump of serial8250_startup()
> and serial8250_shutdown().

And also the assembly dump of serial_in() were the NULL pointer
dereference happens.

José Gonçalves

vmlinux- file format elf32-i386

Disassembly of section .text:

c01bfa70 <serial_in>:
c01bfa70: 55 push %ebp
c01bfa71: 89 e5 mov %esp,%ebp
c01bfa73: 53 push %ebx
c01bfa74: 8b 5d 08 mov 0x8(%ebp),%ebx
c01bfa77: 8b 55 0c mov 0xc(%ebp),%edx
c01bfa7a: 0f b6 4b 12 movzbl 0x12(%ebx),%ecx
c01bfa7e: 0f b6 43 13 movzbl 0x13(%ebx),%eax
c01bfa82: d3 e2 shl %cl,%edx
c01bfa84: 83 f8 02 cmp $0x2,%eax
c01bfa87: 74 1a je c01bfaa3 <serial_in+0x33>
c01bfa89: 7f 05 jg c01bfa90 <serial_in+0x20>
c01bfa8b: 48 dec %eax
c01bfa8c: 74 09 je c01bfa97 <serial_in+0x27>
c01bfa8e: eb 21 jmp c01bfab1 <serial_in+0x41>
c01bfa90: 83 f8 03 cmp $0x3,%eax
c01bfa93: 74 15 je c01bfaaa <serial_in+0x3a>
c01bfa95: eb 1a jmp c01bfab1 <serial_in+0x41>
c01bfa97: 8a 43 78 mov 0x78(%ebx),%al
c01bfa9a: 01 d0 add %edx,%eax
c01bfa9c: 8b 13 mov (%ebx),%edx
c01bfa9e: 48 dec %eax
c01bfa9f: ee out %al,(%dx)
c01bfaa0: 42 inc %edx
c01bfaa1: eb 10 jmp c01bfab3 <serial_in+0x43>
c01bfaa3: 03 53 04 add 0x4(%ebx),%edx
c01bfaa6: 8a 02 mov (%edx),%al
c01bfaa8: eb 0a jmp c01bfab4 <serial_in+0x44>
c01bfaaa: 03 53 04 add 0x4(%ebx),%edx
c01bfaad: 8b 02 mov (%edx),%eax
c01bfaaf: eb 06 jmp c01bfab7 <serial_in+0x47>
c01bfab1: 03 13 add (%ebx),%edx
c01bfab3: ec in (%dx),%al
c01bfab4: 0f b6 c0 movzbl %al,%eax
c01bfab7: 5b pop %ebx
c01bfab8: 5d pop %ebp
c01bfab9: c3 ret
Disassembly of section .init.text:
Disassembly of section .altinstr_replacement:
Disassembly of section .exit.text: