[mirror_ubuntu-artful-kernel.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/sched/debug.h>
#include <linux/sched/task_stack.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>
b17b0153	7	#include <linux/sched/debug.h>
68db0cf1	8	#include <linux/sched/task_stack.h>
1df0f0ff	9	#include <linux/stacktrace.h>
73bc256d	10	#include <linux/export.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,
e1e16115	17	unsigned long reg29, int savesched)
1df0f0ff AN	18	{
	19	unsigned long sp = (unsigned long )reg29;
	20	unsigned long addr;
	21
	22	while (!kstack_end(sp)) {
	23	addr = *sp++;
e1e16115 AK	24	if (__kernel_text_address(addr) &&
e1e16115 AK	25	(savesched \|\| !in_sched_functions(addr))) {
23126692 AN	26	if (trace->skip > 0)
23126692 AN	27	trace->skip--;
1df0f0ff	28	else
23126692	29	trace->entries[trace->nr_entries++] = addr;
1df0f0ff AN	30	if (trace->nr_entries >= trace->max_entries)
	31	break;
	32	}
	33	}
	34	}
	35
2ec220e2	36	static void save_context_stack(struct stack_trace *trace,
e1e16115	37	struct task_struct tsk, struct pt_regs regs, int savesched)
1df0f0ff AN	38	{
	39	unsigned long sp = regs->regs[29];
	40	#ifdef CONFIG_KALLSYMS
	41	unsigned long ra = regs->regs[31];
	42	unsigned long pc = regs->cp0_epc;
1df0f0ff AN	43
1df0f0ff AN	44	if (raw_show_trace \|\| !__kernel_text_address(pc)) {
1924600c	45	unsigned long stack_page =
2ec220e2	46	(unsigned long)task_stack_page(tsk);
23126692 AN	47	if (stack_page && sp >= stack_page &&
23126692 AN	48	sp <= stack_page + THREAD_SIZE - 32)
e1e16115	49	save_raw_context_stack(trace, sp, savesched);
1924600c	50	return;
1df0f0ff AN	51	}
1df0f0ff AN	52	do {
e1e16115 AK	53	if (savesched \|\| !in_sched_functions(pc)) {
	54	if (trace->skip > 0)
	55	trace->skip--;
	56	else
	57	trace->entries[trace->nr_entries++] = pc;
	58	if (trace->nr_entries >= trace->max_entries)
	59	break;
	60	}
2ec220e2	61	pc = unwind_stack(tsk, &sp, pc, &ra);
1df0f0ff AN	62	} while (pc);
1df0f0ff AN	63	#else
e1e16115	64	save_raw_context_stack(trace, sp, savesched);
1df0f0ff	65	#endif
1df0f0ff AN	66	}
	67
	68	/*
	69	* Save stack-backtrace addresses into a stack_trace buffer.
1df0f0ff	70	*/
ab1b6f03	71	void save_stack_trace(struct stack_trace *trace)
2ec220e2 KC	72	{
	73	save_stack_trace_tsk(current, trace);
	74	}
	75	EXPORT_SYMBOL_GPL(save_stack_trace);
	76
	77	void save_stack_trace_tsk(struct task_struct tsk, struct stack_trace trace)
1df0f0ff AN	78	{
	79	struct pt_regs dummyregs;
	80	struct pt_regs *regs = &dummyregs;
	81
	82	WARN_ON(trace->nr_entries \|\| !trace->max_entries);
	83
2ec220e2 KC	84	if (tsk != current) {
	85	regs->regs[29] = tsk->thread.reg29;
	86	regs->regs[31] = 0;
	87	regs->cp0_epc = tsk->thread.reg31;
	88	} else
	89	prepare_frametrace(regs);
e1e16115	90	save_context_stack(trace, tsk, regs, tsk == current);
1df0f0ff	91	}
2ec220e2	92	EXPORT_SYMBOL_GPL(save_stack_trace_tsk);