1/*
 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>
 8#include <linux/export.h>
 9#include <asm/stacktrace.h>
10
11/*
12 * Save stack-backtrace addresses into a stack_trace buffer:
13 */
14static void save_raw_context_stack(struct stack_trace *trace,
15	unsigned long reg29, int savesched)
16{
17	unsigned long *sp = (unsigned long *)reg29;
18	unsigned long addr;
19
20	while (!kstack_end(sp)) {
21		addr = *sp++;
22		if (__kernel_text_address(addr) &&
23		    (savesched || !in_sched_functions(addr))) {
24			if (trace->skip > 0)
25				trace->skip--;
26			else
27				trace->entries[trace->nr_entries++] = addr;
28			if (trace->nr_entries >= trace->max_entries)
29				break;
30		}
31	}
32}
33
34static void save_context_stack(struct stack_trace *trace,
35	struct task_struct *tsk, struct pt_regs *regs, int savesched)
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;
41
42	if (raw_show_trace || !__kernel_text_address(pc)) {
43		unsigned long stack_page =
44			(unsigned long)task_stack_page(tsk);
45		if (stack_page && sp >= stack_page &&
46		    sp <= stack_page + THREAD_SIZE - 32)
47			save_raw_context_stack(trace, sp, savesched);
48		return;
49	}
50	do {
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		}
59		pc = unwind_stack(tsk, &sp, pc, &ra);
60	} while (pc);
61#else
62	save_raw_context_stack(trace, sp, savesched);
63#endif
64}
65
66/*
67 * Save stack-backtrace addresses into a stack_trace buffer.
68 */
69void save_stack_trace(struct stack_trace *trace)
70{
71	save_stack_trace_tsk(current, trace);
72}
73EXPORT_SYMBOL_GPL(save_stack_trace);
74
75void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
76{
77	struct pt_regs dummyregs;
78	struct pt_regs *regs = &dummyregs;
79
80	WARN_ON(trace->nr_entries || !trace->max_entries);
81
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);
88	save_context_stack(trace, tsk, regs, tsk == current);
89}
90EXPORT_SYMBOL_GPL(save_stack_trace_tsk);

 1// SPDX-License-Identifier: GPL-2.0-only
 2/*
 3 * Stack trace management functions
 4 *
 5 *  Copyright (C) 2006 Atsushi Nemoto <anemo@mba.ocn.ne.jp>
 6 */
 7#include <linux/sched.h>
 8#include <linux/sched/debug.h>
 9#include <linux/sched/task_stack.h>
10#include <linux/stacktrace.h>
11#include <linux/export.h>
12#include <asm/stacktrace.h>
13
14/*
15 * Save stack-backtrace addresses into a stack_trace buffer:
16 */
17static void save_raw_context_stack(struct stack_trace *trace,
18	unsigned long reg29, int savesched)
19{
20	unsigned long *sp = (unsigned long *)reg29;
21	unsigned long addr;
22
23	while (!kstack_end(sp)) {
24		addr = *sp++;
25		if (__kernel_text_address(addr) &&
26		    (savesched || !in_sched_functions(addr))) {
27			if (trace->skip > 0)
28				trace->skip--;
29			else
30				trace->entries[trace->nr_entries++] = addr;
31			if (trace->nr_entries >= trace->max_entries)
32				break;
33		}
34	}
35}
36
37static void save_context_stack(struct stack_trace *trace,
38	struct task_struct *tsk, struct pt_regs *regs, int savesched)
39{
40	unsigned long sp = regs->regs[29];
41#ifdef CONFIG_KALLSYMS
42	unsigned long ra = regs->regs[31];
43	unsigned long pc = regs->cp0_epc;
44
45	if (raw_show_trace || !__kernel_text_address(pc)) {
46		unsigned long stack_page =
47			(unsigned long)task_stack_page(tsk);
48		if (stack_page && sp >= stack_page &&
49		    sp <= stack_page + THREAD_SIZE - 32)
50			save_raw_context_stack(trace, sp, savesched);
51		return;
52	}
53	do {
54		if (savesched || !in_sched_functions(pc)) {
55			if (trace->skip > 0)
56				trace->skip--;
57			else
58				trace->entries[trace->nr_entries++] = pc;
59			if (trace->nr_entries >= trace->max_entries)
60				break;
61		}
62		pc = unwind_stack(tsk, &sp, pc, &ra);
63	} while (pc);
64#else
65	save_raw_context_stack(trace, sp, savesched);
66#endif
67}
68
69/*
70 * Save stack-backtrace addresses into a stack_trace buffer.
71 */
72void save_stack_trace(struct stack_trace *trace)
73{
74	save_stack_trace_tsk(current, trace);
75}
76EXPORT_SYMBOL_GPL(save_stack_trace);
77
78void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
79{
80	struct pt_regs dummyregs;
81	struct pt_regs *regs = &dummyregs;
82
83	WARN_ON(trace->nr_entries || !trace->max_entries);
84
85	if (tsk != current) {
86		regs->regs[29] = tsk->thread.reg29;
87		regs->regs[31] = 0;
88		regs->cp0_epc = tsk->thread.reg31;
89	} else
90		prepare_frametrace(regs);
91	save_context_stack(trace, tsk, regs, tsk == current);
92}
93EXPORT_SYMBOL_GPL(save_stack_trace_tsk);