Jose Goncalves wrote: > New devolpments. > I have upgraded to 2.6.16.41, applied a patch sent by Frederik that > removed the changed made in http://lkml.org/lkml/2005/6/23/266 and > activated some more kernel debug, i.e., CONFIG_KALLSYMS_ALL, > CONFIG_DEBUG_KERNEL, CONFIG_DETECT_SOFTLOCKUP, CONFIG_DEBUG_SLAB, > CONFIG_DEBUG_MUTEXES, CONFIG_FRAME_POINTER and CONFIG_FORCED_INLINING > (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-2.6.16.41-mtm5-debug1: 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:
