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 map_groups *mg,
16 			  struct unwind_libunwind_ops *ops)
17 {
18 	mg->unwind_libunwind_ops = ops;
19 }
20 
21 int unwind__prepare_access(struct map_groups *mg, struct map *map,
22 			   bool *initialized)
23 {
24 	const char *arch;
25 	enum dso_type dso_type;
26 	struct unwind_libunwind_ops *ops = local_unwind_libunwind_ops;
27 	int err;
28 
29 	if (!dwarf_callchain_users)
30 		return 0;
31 
32 	if (mg->addr_space) {
33 		pr_debug("unwind: thread map already set, dso=%s\n",
34 			 map->dso->name);
35 		if (initialized)
36 			*initialized = true;
37 		return 0;
38 	}
39 
40 	/* env->arch is NULL for live-mode (i.e. perf top) */
41 	if (!mg->machine->env || !mg->machine->env->arch)
42 		goto out_register;
43 
44 	dso_type = dso__type(map->dso, mg->machine);
45 	if (dso_type == DSO__TYPE_UNKNOWN)
46 		return 0;
47 
48 	arch = perf_env__arch(mg->machine->env);
49 
50 	if (!strcmp(arch, "x86")) {
51 		if (dso_type != DSO__TYPE_64BIT)
52 			ops = x86_32_unwind_libunwind_ops;
53 	} else if (!strcmp(arch, "arm64") || !strcmp(arch, "arm")) {
54 		if (dso_type == DSO__TYPE_64BIT)
55 			ops = arm64_unwind_libunwind_ops;
56 	}
57 
58 	if (!ops) {
59 		pr_err("unwind: target platform=%s is not supported\n", arch);
60 		return 0;
61 	}
62 out_register:
63 	unwind__register_ops(mg, ops);
64 
65 	err = mg->unwind_libunwind_ops->prepare_access(mg);
66 	if (initialized)
67 		*initialized = err ? false : true;
68 	return err;
69 }
70 
71 void unwind__flush_access(struct map_groups *mg)
72 {
73 	if (mg->unwind_libunwind_ops)
74 		mg->unwind_libunwind_ops->flush_access(mg);
75 }
76 
77 void unwind__finish_access(struct map_groups *mg)
78 {
79 	if (mg->unwind_libunwind_ops)
80 		mg->unwind_libunwind_ops->finish_access(mg);
81 }
82 
83 int unwind__get_entries(unwind_entry_cb_t cb, void *arg,
84 			 struct thread *thread,
85 			 struct perf_sample *data, int max_stack)
86 {
87 	if (thread->mg->unwind_libunwind_ops)
88 		return thread->mg->unwind_libunwind_ops->get_entries(cb, arg, thread, data, max_stack);
89 	return 0;
90 }
91