1// SPDX-License-Identifier: GPL-2.0
 2/*
 3 * Stack trace management functions
 4 *
 5 *  Copyright IBM Corp. 2006
 
 6 */
 7
 
 
 8#include <linux/stacktrace.h>
 9#include <asm/stacktrace.h>
10#include <asm/unwind.h>
11#include <asm/kprobes.h>
12
13void arch_stack_walk(stack_trace_consume_fn consume_entry, void *cookie,
14		     struct task_struct *task, struct pt_regs *regs)
15{
16	struct unwind_state state;
17	unsigned long addr;
18
19	unwind_for_each_frame(&state, task, regs, 0) {
20		addr = unwind_get_return_address(&state);
21		if (!addr || !consume_entry(cookie, addr))
22			break;
23	}
 
 
 
 
 
24}
25
26int arch_stack_walk_reliable(stack_trace_consume_fn consume_entry,
27			     void *cookie, struct task_struct *task)
28{
29	struct unwind_state state;
30	unsigned long addr;
31
32	unwind_for_each_frame(&state, task, NULL, 0) {
33		if (state.stack_info.type != STACK_TYPE_TASK)
34			return -EINVAL;
35
36		if (state.regs)
37			return -EINVAL;
38
39		addr = unwind_get_return_address(&state);
40		if (!addr)
41			return -EINVAL;
42
43#ifdef CONFIG_KPROBES
44		/*
45		 * Mark stacktraces with kretprobed functions on them
46		 * as unreliable.
47		 */
48		if (state.ip == (unsigned long)__kretprobe_trampoline)
49			return -EINVAL;
50#endif
51
52		if (!consume_entry(cookie, addr))
53			return -EINVAL;
54	}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
55
56	/* Check for stack corruption */
57	if (unwind_error(&state))
58		return -EINVAL;
59	return 0;
60}

 1// SPDX-License-Identifier: GPL-2.0
 2/*
 3 * Stack trace management functions
 4 *
 5 *  Copyright IBM Corp. 2006
 6 *  Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>
 7 */
 8
 9#include <linux/sched.h>
10#include <linux/sched/debug.h>
11#include <linux/stacktrace.h>
12#include <linux/kallsyms.h>
13#include <linux/export.h>
14
15static int __save_address(void *data, unsigned long address, int nosched)
16{
17	struct stack_trace *trace = data;
18
19	if (nosched && in_sched_functions(address))
20		return 0;
21	if (trace->skip > 0) {
22		trace->skip--;
23		return 0;
 
 
24	}
25	if (trace->nr_entries < trace->max_entries) {
26		trace->entries[trace->nr_entries++] = address;
27		return 0;
28	}
29	return 1;
30}
31
32static int save_address(void *data, unsigned long address, int reliable)
 
33{
34	return __save_address(data, address, 0);
35}
36
37static int save_address_nosched(void *data, unsigned long address, int reliable)
38{
39	return __save_address(data, address, 1);
40}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
41
42void save_stack_trace(struct stack_trace *trace)
43{
44	unsigned long sp;
45
46	sp = current_stack_pointer();
47	dump_trace(save_address, trace, NULL, sp);
48	if (trace->nr_entries < trace->max_entries)
49		trace->entries[trace->nr_entries++] = ULONG_MAX;
50}
51EXPORT_SYMBOL_GPL(save_stack_trace);
52
53void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
54{
55	unsigned long sp;
56
57	sp = tsk->thread.ksp;
58	if (tsk == current)
59		sp = current_stack_pointer();
60	dump_trace(save_address_nosched, trace, tsk, sp);
61	if (trace->nr_entries < trace->max_entries)
62		trace->entries[trace->nr_entries++] = ULONG_MAX;
63}
64EXPORT_SYMBOL_GPL(save_stack_trace_tsk);
65
66void save_stack_trace_regs(struct pt_regs *regs, struct stack_trace *trace)
67{
68	unsigned long sp;
69
70	sp = kernel_stack_pointer(regs);
71	dump_trace(save_address, trace, NULL, sp);
72	if (trace->nr_entries < trace->max_entries)
73		trace->entries[trace->nr_entries++] = ULONG_MAX;
74}
75EXPORT_SYMBOL_GPL(save_stack_trace_regs);