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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/sched/debug.h>
8#include <linux/sched/task_stack.h>
9#include <linux/stacktrace.h>
10#include <linux/export.h>
11#include <asm/stacktrace.h>
12
13/*
14 * Save stack-backtrace addresses into a stack_trace buffer:
15 */
16static void save_raw_context_stack(struct stack_trace *trace,
17 unsigned long reg29, int savesched)
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) &&
25 (savesched || !in_sched_functions(addr))) {
26 if (trace->skip > 0)
27 trace->skip--;
28 else
29 trace->entries[trace->nr_entries++] = addr;
30 if (trace->nr_entries >= trace->max_entries)
31 break;
32 }
33 }
34}
35
36static void save_context_stack(struct stack_trace *trace,
37 struct task_struct *tsk, struct pt_regs *regs, int savesched)
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;
43
44 if (raw_show_trace || !__kernel_text_address(pc)) {
45 unsigned long stack_page =
46 (unsigned long)task_stack_page(tsk);
47 if (stack_page && sp >= stack_page &&
48 sp <= stack_page + THREAD_SIZE - 32)
49 save_raw_context_stack(trace, sp, savesched);
50 return;
51 }
52 do {
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 }
61 pc = unwind_stack(tsk, &sp, pc, &ra);
62 } while (pc);
63#else
64 save_raw_context_stack(trace, sp, savesched);
65#endif
66}
67
68/*
69 * Save stack-backtrace addresses into a stack_trace buffer.
70 */
71void save_stack_trace(struct stack_trace *trace)
72{
73 save_stack_trace_tsk(current, trace);
74}
75EXPORT_SYMBOL_GPL(save_stack_trace);
76
77void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
78{
79 struct pt_regs dummyregs;
80 struct pt_regs *regs = &dummyregs;
81
82 WARN_ON(trace->nr_entries || !trace->max_entries);
83
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);
90 save_context_stack(trace, tsk, regs, tsk == current);
91}
92EXPORT_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);