x86 32bit call backtrace

需include

driver可以用dump_stack() 這個func來back trace
不過還沒有試過，能不能work還未知

底下是x86 32bit的實作

http://lxr.linux.no/linux+v2.6.27.2/arch/x86/kernel/traps_32.c#L288
void dump_stack(void)
{
        unsigned long bp = 0;
        unsigned long stack;

#ifdef CONFIG_FRAME_POINTER
        if (!bp)
                asm("movl %%ebp, %0" : "=r" (bp):);
#endif

        printk("Pid: %d, comm: %.20s %s %s %.*s\n",
                current->pid, current->comm, print_tainted(),
                init_utsname()->release,
                (int)strcspn(init_utsname()->version, " "),
                init_utsname()->version);

        show_trace(current, NULL, &stack, bp);
}

EXPORT_SYMBOL(dump_stack);