 #ifdef CONFIG_SMP spin_unlock(&current->mm->page_table_lock); #endif 
x86_backtrace(struct pt_regs * const regs, unsigned int depth){	struct frame_head *head;#ifdef CONFIG_X86_64	head = (struct frame_head *)regs->rbp;#else	head = (struct frame_head *)regs->ebp;#endif	if (!user_mode_vm(regs)) {		while (depth-- && valid_kernel_stack(head, regs))			head = dump_backtrace(head);		return;	}#ifdef CONFIG_SMP	if (!spin_trylock(&current->mm->page_table_lock))		return;#endif	while (depth-- && head && pages_present(head))		head = dump_backtrace(head);#ifdef CONFIG_SMP	spin_unlock(&current->mm->page_table_lock);#endif}
4520	/local/tlutelli/issta_data/temp/c/2005_temp/2005/4520/c34d1b4d165c67b966bca4aba026443d7ff161eb/backtrace.c/buggy/arch/i386/oprofile/backtrace.c