1 // SPDX-License-Identifier: GPL-2.0
2 #include "unwind.h"
3 #include "thread.h"
4 #include "session.h"
5 #include "debug.h"
6 #include "env.h"
7 
8 struct unwind_libunwind_ops __weak *local_unwind_libunwind_ops;
9 struct unwind_libunwind_ops __weak *x86_32_unwind_libunwind_ops;
10 struct unwind_libunwind_ops __weak *arm64_unwind_libunwind_ops;
11 
12 static void unwind__register_ops(struct thread *thread,
13 			  struct unwind_libunwind_ops *ops)
14 {
15 	thread->unwind_libunwind_ops = ops;
16 }
17 
18 int unwind__prepare_access(struct thread *thread, struct map *map,
19 			   bool *initialized)
20 {
21 	const char *arch;
22 	enum dso_type dso_type;
23 	struct unwind_libunwind_ops *ops = local_unwind_libunwind_ops;
24 	int err;
25 
26 	if (thread->addr_space) {
27 		pr_debug("unwind: thread map already set, dso=%s\n",
28 			 map->dso->name);
29 		if (initialized)
30 			*initialized = true;
31 		return 0;
32 	}
33 
34 	/* env->arch is NULL for live-mode (i.e. perf top) */
35 	if (!thread->mg->machine->env || !thread->mg->machine->env->arch)
36 		goto out_register;
37 
38 	dso_type = dso__type(map->dso, thread->mg->machine);
39 	if (dso_type == DSO__TYPE_UNKNOWN)
40 		return 0;
41 
42 	arch = perf_env__arch(thread->mg->machine->env);
43 
44 	if (!strcmp(arch, "x86")) {
45 		if (dso_type != DSO__TYPE_64BIT)
46 			ops = x86_32_unwind_libunwind_ops;
47 	} else if (!strcmp(arch, "arm64") || !strcmp(arch, "arm")) {
48 		if (dso_type == DSO__TYPE_64BIT)
49 			ops = arm64_unwind_libunwind_ops;
50 	}
51 
52 	if (!ops) {
53 		pr_err("unwind: target platform=%s is not supported\n", arch);
54 		return 0;
55 	}
56 out_register:
57 	unwind__register_ops(thread, ops);
58 
59 	err = thread->unwind_libunwind_ops->prepare_access(thread);
60 	if (initialized)
61 		*initialized = err ? false : true;
62 	return err;
63 }
64 
65 void unwind__flush_access(struct thread *thread)
66 {
67 	if (thread->unwind_libunwind_ops)
68 		thread->unwind_libunwind_ops->flush_access(thread);
69 }
70 
71 void unwind__finish_access(struct thread *thread)
72 {
73 	if (thread->unwind_libunwind_ops)
74 		thread->unwind_libunwind_ops->finish_access(thread);
75 }
76 
77 int unwind__get_entries(unwind_entry_cb_t cb, void *arg,
78 			 struct thread *thread,
79 			 struct perf_sample *data, int max_stack)
80 {
81 	if (thread->unwind_libunwind_ops)
82 		return thread->unwind_libunwind_ops->get_entries(cb, arg, thread, data, max_stack);
83 	return 0;
84 }
85