[linux-2.6-block.git] / arch / mips / kernel / stacktrace.c

/*
 * arch/mips/kernel/stacktrace.c
 *
 * Stack trace management functions
 *
 *  Copyright (C) 2006 Atsushi Nemoto <anemo@mba.ocn.ne.jp>
 */
#include <linux/sched.h>
#include <linux/stacktrace.h>
#include <linux/module.h>
#include <asm/stacktrace.h>

/*
 * Save stack-backtrace addresses into a stack_trace buffer:
 */
static void save_raw_context_stack(struct stack_trace *trace,
	unsigned long reg29)
{
	unsigned long *sp = (unsigned long *)reg29;
	unsigned long addr;

	while (!kstack_end(sp)) {
		addr = *sp++;
		if (__kernel_text_address(addr)) {
			if (trace->skip > 0)
				trace->skip--;
			else
				trace->entries[trace->nr_entries++] = addr;
			if (trace->nr_entries >= trace->max_entries)
				break;
		}
	}
}

static void save_context_stack(struct stack_trace *trace,
	struct task_struct *tsk, struct pt_regs *regs)
{
	unsigned long sp = regs->regs[29];
#ifdef CONFIG_KALLSYMS
	unsigned long ra = regs->regs[31];
	unsigned long pc = regs->cp0_epc;

	if (raw_show_trace || !__kernel_text_address(pc)) {
		unsigned long stack_page =
			(unsigned long)task_stack_page(tsk);
		if (stack_page && sp >= stack_page &&
		    sp <= stack_page + THREAD_SIZE - 32)
			save_raw_context_stack(trace, sp);
		return;
	}
	do {
		if (trace->skip > 0)
			trace->skip--;
		else
			trace->entries[trace->nr_entries++] = pc;
		if (trace->nr_entries >= trace->max_entries)
			break;
		pc = unwind_stack(tsk, &sp, pc, &ra);
	} while (pc);
#else
	save_raw_context_stack(trace, sp);
#endif
}

/*
 * Save stack-backtrace addresses into a stack_trace buffer.
 */
void save_stack_trace(struct stack_trace *trace)
{
	save_stack_trace_tsk(current, trace);
}
EXPORT_SYMBOL_GPL(save_stack_trace);

void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
{
	struct pt_regs dummyregs;
	struct pt_regs *regs = &dummyregs;

	WARN_ON(trace->nr_entries || !trace->max_entries);

	if (tsk != current) {
		regs->regs[29] = tsk->thread.reg29;
		regs->regs[31] = 0;
		regs->cp0_epc = tsk->thread.reg31;
	} else
		prepare_frametrace(regs);
	save_context_stack(trace, tsk, regs);
}
EXPORT_SYMBOL_GPL(save_stack_trace_tsk);
Commit	Line	Data
1df0f0ff AN	1	/*
	2	* arch/mips/kernel/stacktrace.c
	3	*
	4	* Stack trace management functions
	5	*
	6	* Copyright (C) 2006 Atsushi Nemoto <anemo@mba.ocn.ne.jp>
	7	*/
	8	#include <linux/sched.h>
	9	#include <linux/stacktrace.h>
36bd53d0	10	#include <linux/module.h>
1df0f0ff AN	11	#include <asm/stacktrace.h>
	12
	13	/*
	14	* Save stack-backtrace addresses into a stack_trace buffer:
	15	*/
	16	static void save_raw_context_stack(struct stack_trace *trace,
23126692	17	unsigned long reg29)
1df0f0ff AN	18	{
	19	unsigned long sp = (unsigned long )reg29;
	20	unsigned long addr;
	21
	22	while (!kstack_end(sp)) {
	23	addr = *sp++;
	24	if (__kernel_text_address(addr)) {
23126692 AN	25	if (trace->skip > 0)
23126692 AN	26	trace->skip--;
1df0f0ff	27	else
23126692	28	trace->entries[trace->nr_entries++] = addr;
1df0f0ff AN	29	if (trace->nr_entries >= trace->max_entries)
	30	break;
	31	}
	32	}
	33	}
	34
2ec220e2 KC	35	static void save_context_stack(struct stack_trace *trace,
2ec220e2 KC	36	struct task_struct tsk, struct pt_regs regs)
1df0f0ff AN	37	{
	38	unsigned long sp = regs->regs[29];
	39	#ifdef CONFIG_KALLSYMS
	40	unsigned long ra = regs->regs[31];
	41	unsigned long pc = regs->cp0_epc;
1df0f0ff AN	42
1df0f0ff AN	43	if (raw_show_trace \|\| !__kernel_text_address(pc)) {
1924600c	44	unsigned long stack_page =
2ec220e2	45	(unsigned long)task_stack_page(tsk);
23126692 AN	46	if (stack_page && sp >= stack_page &&
	47	sp <= stack_page + THREAD_SIZE - 32)
	48	save_raw_context_stack(trace, sp);
1924600c	49	return;
1df0f0ff AN	50	}
1df0f0ff AN	51	do {
23126692 AN	52	if (trace->skip > 0)
23126692 AN	53	trace->skip--;
1df0f0ff	54	else
23126692	55	trace->entries[trace->nr_entries++] = pc;
1df0f0ff AN	56	if (trace->nr_entries >= trace->max_entries)
1df0f0ff AN	57	break;
2ec220e2	58	pc = unwind_stack(tsk, &sp, pc, &ra);
1df0f0ff AN	59	} while (pc);
1df0f0ff AN	60	#else
eea32d4c	61	save_raw_context_stack(trace, sp);
1df0f0ff	62	#endif
1df0f0ff AN	63	}
	64
	65	/*
	66	* Save stack-backtrace addresses into a stack_trace buffer.
1df0f0ff	67	*/
ab1b6f03	68	void save_stack_trace(struct stack_trace *trace)
2ec220e2 KC	69	{
	70	save_stack_trace_tsk(current, trace);
	71	}
	72	EXPORT_SYMBOL_GPL(save_stack_trace);
	73
	74	void save_stack_trace_tsk(struct task_struct tsk, struct stack_trace trace)
1df0f0ff AN	75	{
	76	struct pt_regs dummyregs;
	77	struct pt_regs *regs = &dummyregs;
	78
	79	WARN_ON(trace->nr_entries \|\| !trace->max_entries);
	80
2ec220e2 KC	81	if (tsk != current) {
	82	regs->regs[29] = tsk->thread.reg29;
	83	regs->regs[31] = 0;
	84	regs->cp0_epc = tsk->thread.reg31;
	85	} else
	86	prepare_frametrace(regs);
	87	save_context_stack(trace, tsk, regs);
1df0f0ff	88	}
2ec220e2	89	EXPORT_SYMBOL_GPL(save_stack_trace_tsk);