1 // SPDX-License-Identifier: GPL-2.0
2 #include "unwind.h"
3 #include "dso.h"
4 #include "map.h"
5 #include "thread.h"
6 #include "session.h"
7 #include "debug.h"
8 #include "env.h"
9 #include "callchain.h"
10 
11 struct unwind_libunwind_ops __weak *local_unwind_libunwind_ops;
12 struct unwind_libunwind_ops __weak *x86_32_unwind_libunwind_ops;
13 struct unwind_libunwind_ops __weak *arm64_unwind_libunwind_ops;
14 
15 static void unwind__register_ops(struct maps *maps, struct unwind_libunwind_ops *ops)
16 {
17 	maps->unwind_libunwind_ops = ops;
18 }
19 
20 int unwind__prepare_access(struct maps *maps, struct map *map, bool *initialized)
21 {
22 	const char *arch;
23 	enum dso_type dso_type;
24 	struct unwind_libunwind_ops *ops = local_unwind_libunwind_ops;
25 	int err;
26 
27 	if (!dwarf_callchain_users)
28 		return 0;
29 
30 	if (maps->addr_space) {
31 		pr_debug("unwind: thread map already set, dso=%s\n",
32 			 map->dso->name);
33 		if (initialized)
34 			*initialized = true;
35 		return 0;
36 	}
37 
38 	/* env->arch is NULL for live-mode (i.e. perf top) */
39 	if (!maps->machine->env || !maps->machine->env->arch)
40 		goto out_register;
41 
42 	dso_type = dso__type(map->dso, maps->machine);
43 	if (dso_type == DSO__TYPE_UNKNOWN)
44 		return 0;
45 
46 	arch = perf_env__arch(maps->machine->env);
47 
48 	if (!strcmp(arch, "x86")) {
49 		if (dso_type != DSO__TYPE_64BIT)
50 			ops = x86_32_unwind_libunwind_ops;
51 	} else if (!strcmp(arch, "arm64") || !strcmp(arch, "arm")) {
52 		if (dso_type == DSO__TYPE_64BIT)
53 			ops = arm64_unwind_libunwind_ops;
54 	}
55 
56 	if (!ops) {
57 		pr_err("unwind: target platform=%s is not supported\n", arch);
58 		return 0;
59 	}
60 out_register:
61 	unwind__register_ops(maps, ops);
62 
63 	err = maps->unwind_libunwind_ops->prepare_access(maps);
64 	if (initialized)
65 		*initialized = err ? false : true;
66 	return err;
67 }
68 
69 void unwind__flush_access(struct maps *maps)
70 {
71 	if (maps->unwind_libunwind_ops)
72 		maps->unwind_libunwind_ops->flush_access(maps);
73 }
74 
75 void unwind__finish_access(struct maps *maps)
76 {
77 	if (maps->unwind_libunwind_ops)
78 		maps->unwind_libunwind_ops->finish_access(maps);
79 }
80 
81 int unwind__get_entries(unwind_entry_cb_t cb, void *arg,
82 			 struct thread *thread,
83 			 struct perf_sample *data, int max_stack)
84 {
85 	if (thread->maps->unwind_libunwind_ops)
86 		return thread->maps->unwind_libunwind_ops->get_entries(cb, arg, thread, data, max_stack);
87 	return 0;
88 }
89