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
arch_stack_walk(stack_trace_consume_fn consume_entry,void * cookie,struct task_struct * task,struct pt_regs * regs)13 void 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
arch_stack_walk_reliable(stack_trace_consume_fn consume_entry,void * cookie,struct task_struct * task)26 int 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_RETHOOK
44 /*
45 * Mark stacktraces with krethook functions on them
46 * as unreliable.
47 */
48 if (state.ip == (unsigned long)arch_rethook_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 }
61