cvs commit: src/gnu/usr.bin/gdb/kgdb kgdb.h main.c trgt.c

[John Baldwin]

On Thursday 17 January 2008 04:43:12 pm John Baldwin wrote:
> jhb         2008-01-17 21:43:12 UTC
> 
>   FreeBSD src repository
> 
>   Modified files:
>     gnu/usr.bin/gdb/kgdb kgdb.h main.c trgt.c 
>   Log:
>   Add a new 'add-kld <kld>' command to kgdb to make it easier to analyze
>   crash dumps with kernel modules.  The command is basically a wrapper
>   around add-symbol-file except that it uses the kernel linker data
>   structures and the ELF section headers of the kld to calculate the
>   section addresses add-symbol-file needs.

Forgot to say:

Tested on:	i386, amd64

A sample run on i386:

> sudo ./kgdb -c /usr/crash/vmcore.10 /boot/kernel/kernel
...
crash: blow the kernel stack on purpose

Fatal double fault:
eip = 0xc05c6220
esp = 0xe61b0000
ebp = 0xe61b0018
panic: double fault
KDB: enter: panic
...
(kgdb) where
#0  doadump () at pcpu.h:195
#1  0xc05d399c in boot (howto=260) at /usr/src/sys/kern/kern_shutdown.c:417
#2  0xc05d3c0a in panic (fmt=Variable "fmt" is not available.
) at /usr/src/sys/kern/kern_shutdown.c:571
#3  0xc08115d9 in dblfault_handler () at /usr/src/sys/i386/i386/trap.c:927
#4  0xc05c6220 in mtx_pool_setup_dynamic ()
#5  0xc065e125 in arc4rand (ptr=0xe61b0168, len=4, reseed=0)
    at /usr/src/sys/libkern/arc4random.c:142
#6  0xc065e171 in arc4random () at /usr/src/sys/libkern/arc4random.c:150
#7  0xc3d43402 in ?? ()
#8  0xb15ac28c in ?? ()
#9  0x793b5626 in ?? ()
#10 0xe61b018c in ?? ()
#11 0xc3d43410 in ?? ()
#12 0xbc8e58bf in ?? ()
...
(kgdb) add-kld crash.ko
add symbol table from file "/boot/modules/crash.ko.symbols" at
        .text_addr = 0xc3d416f0
        .data_addr = 0xc3d44000
        .bss_addr = 0xc3d44254
        .rodata_addr = 0xc3d4364e
Reading symbols from /boot/modules/crash.ko.symbols...done.
(kgdb) where
#0  doadump () at pcpu.h:195
#1  0xc05d399c in boot (howto=260) at /usr/src/sys/kern/kern_shutdown.c:417
#2  0xc05d3c0a in panic (fmt=Variable "fmt" is not available.
) at /usr/src/sys/kern/kern_shutdown.c:571
#3  0xc08115d9 in dblfault_handler () at /usr/src/sys/i386/i386/trap.c:927
#4  0xc05c6220 in mtx_pool_setup_dynamic ()
#5  0xc065e125 in arc4rand (ptr=0xe61b0168, len=4, reseed=0)
    at /usr/src/sys/libkern/arc4random.c:142
#6  0xc065e171 in arc4random () at /usr/src/sys/libkern/arc4random.c:150
#7  0xc3d43402 in blow_stack () at crash.c:773
#8  0xc3d43410 in blow_stack () at crash.c:764
#9  0xc3d43410 in blow_stack () at crash.c:764
#10 0xc3d43410 in blow_stack () at crash.c:764
#11 0xc3d43410 in blow_stack () at crash.c:764
#12 0xc3d43410 in blow_stack () at crash.c:764
#13 0xc3d43410 in blow_stack () at crash.c:764
#14 0xc3d43410 in blow_stack () at crash.c:764
#15 0xc3d43410 in blow_stack () at crash.c:764
#16 0xc3d43410 in blow_stack () at crash.c:764
#17 0xc3d43410 in blow_stack () at crash.c:764
#18 0xc3d43410 in blow_stack () at crash.c:764
#19 0xc3d43410 in blow_stack () at crash.c:764

-- 
John Baldwin