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/* Provide basic stack dumping functions * * Copyright 2004-2009 Analog Devices Inc. * * Licensed under the GPL-2 or later */ #include <linux/kernel.h>#include <linux/thread_info.h>#include <linux/mm.h>#include <linux/uaccess.h>#include <linux/module.h>#include <asm/trace.h> /* * Checks to see if the address pointed to is either a * 16-bit CALL instruction, or a 32-bit CALL instruction */static bool is_bfin_call(unsigned short *addr){	unsigned int opcode; 	if (!get_instruction(&opcode, addr))		return false; 	if ((opcode >= 0x0060 && opcode <= 0x0067) ||	    (opcode >= 0x0070 && opcode <= 0x0077) ||	    (opcode >= 0xE3000000 && opcode <= 0xE3FFFFFF))		return true; 	return false; } void show_stack(struct task_struct *task, unsigned long *stack){#ifdef CONFIG_PRINTK	unsigned int *addr, *endstack, *fp = 0, *frame;	unsigned short *ins_addr;	char buf[150];	unsigned int i, j, ret_addr, frame_no = 0; 	/*	 * If we have been passed a specific stack, use that one otherwise	 *    if we have been passed a task structure, use that, otherwise	 *    use the stack of where the variable "stack" exists	 */ 	if (stack == NULL) {		if (task) {			/* We know this is a kernel stack, so this is the start/end */			stack = (unsigned long *)task->thread.ksp;			endstack = (unsigned int *)(((unsigned int)(stack) & ~(THREAD_SIZE - 1)) + THREAD_SIZE);		} else {			/* print out the existing stack info */			stack = (unsigned long *)&stack;			endstack = (unsigned int *)PAGE_ALIGN((unsigned int)stack);		}	} else		endstack = (unsigned int *)PAGE_ALIGN((unsigned int)stack); 	printk(KERN_NOTICE "Stack info:\n");	decode_address(buf, (unsigned int)stack);	printk(KERN_NOTICE " SP: [0x%p] %s\n", stack, buf); 	if (!access_ok(VERIFY_READ, stack, (unsigned int)endstack - (unsigned int)stack)) {		printk(KERN_NOTICE "Invalid stack pointer\n");		return;	} 	/* First thing is to look for a frame pointer */	for (addr = (unsigned int *)((unsigned int)stack & ~0xF); addr < endstack; addr++) {		if (*addr & 0x1)			continue;		ins_addr = (unsigned short *)*addr;		ins_addr--;		if (is_bfin_call(ins_addr))			fp = addr - 1; 		if (fp) {			/* Let's check to see if it is a frame pointer */			while (fp >= (addr - 1) && fp < endstack			       && fp && ((unsigned int) fp & 0x3) == 0)				fp = (unsigned int *)*fp;			if (fp == 0 || fp == endstack) {				fp = addr - 1;				break;			}			fp = 0;		}	}	if (fp) {		frame = fp;		printk(KERN_NOTICE " FP: (0x%p)\n", fp);	} else		frame = 0; 	/*	 * Now that we think we know where things are, we	 * walk the stack again, this time printing things out	 * incase there is no frame pointer, we still look for	 * valid return addresses	 */ 	/* First time print out data, next time, print out symbols */	for (j = 0; j <= 1; j++) {		if (j)			printk(KERN_NOTICE "Return addresses in stack:\n");		else			printk(KERN_NOTICE " Memory from 0x%08lx to %p", ((long unsigned int)stack & ~0xF), endstack); 		fp = frame;		frame_no = 0; 		for (addr = (unsigned int *)((unsigned int)stack & ~0xF), i = 0;		     addr < endstack; addr++, i++) { 			ret_addr = 0;			if (!j && i % 8 == 0)				printk(KERN_NOTICE "%p:", addr); 			/* if it is an odd address, or zero, just skip it */			if (*addr & 0x1 || !*addr)				goto print; 			ins_addr = (unsigned short *)*addr; 			/* Go back one instruction, and see if it is a CALL */			ins_addr--;			ret_addr = is_bfin_call(ins_addr); print:			if (!j && stack == (unsigned long *)addr)				printk("[%08x]", *addr);			else if (ret_addr)				if (j) {					decode_address(buf, (unsigned int)*addr);					if (frame == addr) {						printk(KERN_NOTICE "   frame %2i : %s\n", frame_no, buf);						continue;					}					printk(KERN_NOTICE "    address : %s\n", buf);				} else					printk("<%08x>", *addr);			else if (fp == addr) {				if (j)					frame = addr+1;				else					printk("(%08x)", *addr); 				fp = (unsigned int *)*addr;				frame_no++; 			} else if (!j)				printk(" %08x ", *addr);		}		if (!j)			printk("\n");	}#endif}EXPORT_SYMBOL(show_stack); void dump_stack(void){	unsigned long stack;#ifdef CONFIG_DEBUG_BFIN_HWTRACE_ON	int tflags;#endif	trace_buffer_save(tflags);	dump_bfin_trace_buffer();	dump_stack_print_info(KERN_DEFAULT);	show_stack(current, &stack);	trace_buffer_restore(tflags);}EXPORT_SYMBOL(dump_stack);