xref: /openbmc/linux/arch/s390/kernel/stacktrace.c (revision 5efb685b)
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 
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 
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