[deliverable/linux.git] / 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/export.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, int savesched)
{
	unsigned long *sp = (unsigned long *)reg29;
	unsigned long addr;

	while (!kstack_end(sp)) {
		addr = *sp++;
		if (__kernel_text_address(addr) &&
		    (savesched || !in_sched_functions(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, int savesched)
{
	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, savesched);
		return;
	}
	do {
		if (savesched || !in_sched_functions(pc)) {
			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, savesched);
#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, tsk == current);
}
EXPORT_SYMBOL_GPL(save_stack_trace_tsk);
Commit	Line	Data
1df0f0ff	1	/*
1df0f0ff AN	2	* Stack trace management functions
	3	*
	4	* Copyright (C) 2006 Atsushi Nemoto <anemo@mba.ocn.ne.jp>
	5	*/
	6	#include <linux/sched.h>
	7	#include <linux/stacktrace.h>
73bc256d	8	#include <linux/export.h>
1df0f0ff AN	9	#include <asm/stacktrace.h>
	10
	11	/*
	12	* Save stack-backtrace addresses into a stack_trace buffer:
	13	*/
	14	static void save_raw_context_stack(struct stack_trace *trace,
e1e16115	15	unsigned long reg29, int savesched)
1df0f0ff AN	16	{
	17	unsigned long sp = (unsigned long )reg29;
	18	unsigned long addr;
	19
	20	while (!kstack_end(sp)) {
	21	addr = *sp++;
e1e16115 AK	22	if (__kernel_text_address(addr) &&
e1e16115 AK	23	(savesched \|\| !in_sched_functions(addr))) {
23126692 AN	24	if (trace->skip > 0)
23126692 AN	25	trace->skip--;
1df0f0ff	26	else
23126692	27	trace->entries[trace->nr_entries++] = addr;
1df0f0ff AN	28	if (trace->nr_entries >= trace->max_entries)
	29	break;
	30	}
	31	}
	32	}
	33
2ec220e2	34	static void save_context_stack(struct stack_trace *trace,
e1e16115	35	struct task_struct tsk, struct pt_regs regs, int savesched)
1df0f0ff AN	36	{
	37	unsigned long sp = regs->regs[29];
	38	#ifdef CONFIG_KALLSYMS
	39	unsigned long ra = regs->regs[31];
	40	unsigned long pc = regs->cp0_epc;
1df0f0ff AN	41
1df0f0ff AN	42	if (raw_show_trace \|\| !__kernel_text_address(pc)) {
1924600c	43	unsigned long stack_page =
2ec220e2	44	(unsigned long)task_stack_page(tsk);
23126692 AN	45	if (stack_page && sp >= stack_page &&
23126692 AN	46	sp <= stack_page + THREAD_SIZE - 32)
e1e16115	47	save_raw_context_stack(trace, sp, savesched);
1924600c	48	return;
1df0f0ff AN	49	}
1df0f0ff AN	50	do {
e1e16115 AK	51	if (savesched \|\| !in_sched_functions(pc)) {
	52	if (trace->skip > 0)
	53	trace->skip--;
	54	else
	55	trace->entries[trace->nr_entries++] = pc;
	56	if (trace->nr_entries >= trace->max_entries)
	57	break;
	58	}
2ec220e2	59	pc = unwind_stack(tsk, &sp, pc, &ra);
1df0f0ff AN	60	} while (pc);
1df0f0ff AN	61	#else
e1e16115	62	save_raw_context_stack(trace, sp, savesched);
1df0f0ff	63	#endif
1df0f0ff AN	64	}
	65
	66	/*
	67	* Save stack-backtrace addresses into a stack_trace buffer.
1df0f0ff	68	*/
ab1b6f03	69	void save_stack_trace(struct stack_trace *trace)
2ec220e2 KC	70	{
	71	save_stack_trace_tsk(current, trace);
	72	}
	73	EXPORT_SYMBOL_GPL(save_stack_trace);
	74
	75	void save_stack_trace_tsk(struct task_struct tsk, struct stack_trace trace)
1df0f0ff AN	76	{
	77	struct pt_regs dummyregs;
	78	struct pt_regs *regs = &dummyregs;
	79
	80	WARN_ON(trace->nr_entries \|\| !trace->max_entries);
	81
2ec220e2 KC	82	if (tsk != current) {
	83	regs->regs[29] = tsk->thread.reg29;
	84	regs->regs[31] = 0;
	85	regs->cp0_epc = tsk->thread.reg31;
	86	} else
	87	prepare_frametrace(regs);
e1e16115	88	save_context_stack(trace, tsk, regs, tsk == current);
1df0f0ff	89	}
2ec220e2	90	EXPORT_SYMBOL_GPL(save_stack_trace_tsk);