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/stacktrace.h>
10 #include <asm/stacktrace.h>
11 #include <asm/unwind.h>
12 #include <asm/kprobes.h>
13
arch_stack_walk(stack_trace_consume_fn consume_entry,void * cookie,struct task_struct * task,struct pt_regs * regs)14 void arch_stack_walk(stack_trace_consume_fn consume_entry, void *cookie,
15 struct task_struct *task, struct pt_regs *regs)
16 {
17 struct unwind_state state;
18 unsigned long addr;
19
20 unwind_for_each_frame(&state, task, regs, 0) {
21 addr = unwind_get_return_address(&state);
22 if (!addr || !consume_entry(cookie, addr))
23 break;
24 }
25 }
26
arch_stack_walk_reliable(stack_trace_consume_fn consume_entry,void * cookie,struct task_struct * task)27 int arch_stack_walk_reliable(stack_trace_consume_fn consume_entry,
28 void *cookie, struct task_struct *task)
29 {
30 struct unwind_state state;
31 unsigned long addr;
32
33 unwind_for_each_frame(&state, task, NULL, 0) {
34 if (state.stack_info.type != STACK_TYPE_TASK)
35 return -EINVAL;
36
37 if (state.regs)
38 return -EINVAL;
39
40 addr = unwind_get_return_address(&state);
41 if (!addr)
42 return -EINVAL;
43
44 #ifdef CONFIG_KPROBES
45 /*
46 * Mark stacktraces with kretprobed functions on them
47 * as unreliable.
48 */
49 if (state.ip == (unsigned long)kretprobe_trampoline)
50 return -EINVAL;
51 #endif
52
53 if (!consume_entry(cookie, addr))
54 return -EINVAL;
55 }
56
57 /* Check for stack corruption */
58 if (unwind_error(&state))
59 return -EINVAL;
60 return 0;
61 }
62