xref: /linux/tools/perf/util/unwind-libunwind.c (revision 1e525507)
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 int unwind__prepare_access(struct maps *maps, struct map *map, bool *initialized)
16 {
17 	const char *arch;
18 	enum dso_type dso_type;
19 	struct unwind_libunwind_ops *ops = local_unwind_libunwind_ops;
20 	struct dso *dso = map__dso(map);
21 	struct machine *machine;
22 	int err;
23 
24 	if (!dwarf_callchain_users)
25 		return 0;
26 
27 	if (maps__addr_space(maps)) {
28 		pr_debug("unwind: thread map already set, dso=%s\n", dso->name);
29 		if (initialized)
30 			*initialized = true;
31 		return 0;
32 	}
33 
34 	machine = maps__machine(maps);
35 	/* env->arch is NULL for live-mode (i.e. perf top) */
36 	if (!machine->env || !machine->env->arch)
37 		goto out_register;
38 
39 	dso_type = dso__type(dso, machine);
40 	if (dso_type == DSO__TYPE_UNKNOWN)
41 		return 0;
42 
43 	arch = perf_env__arch(machine->env);
44 
45 	if (!strcmp(arch, "x86")) {
46 		if (dso_type != DSO__TYPE_64BIT)
47 			ops = x86_32_unwind_libunwind_ops;
48 	} else if (!strcmp(arch, "arm64") || !strcmp(arch, "arm")) {
49 		if (dso_type == DSO__TYPE_64BIT)
50 			ops = arm64_unwind_libunwind_ops;
51 	}
52 
53 	if (!ops) {
54 		pr_warning_once("unwind: target platform=%s is not supported\n", arch);
55 		return 0;
56 	}
57 out_register:
58 	maps__set_unwind_libunwind_ops(maps, ops);
59 
60 	err = maps__unwind_libunwind_ops(maps)->prepare_access(maps);
61 	if (initialized)
62 		*initialized = err ? false : true;
63 	return err;
64 }
65 
66 void unwind__flush_access(struct maps *maps)
67 {
68 	const struct unwind_libunwind_ops *ops = maps__unwind_libunwind_ops(maps);
69 
70 	if (ops)
71 		ops->flush_access(maps);
72 }
73 
74 void unwind__finish_access(struct maps *maps)
75 {
76 	const struct unwind_libunwind_ops *ops = maps__unwind_libunwind_ops(maps);
77 
78 	if (ops)
79 		ops->finish_access(maps);
80 }
81 
82 int unwind__get_entries(unwind_entry_cb_t cb, void *arg,
83 			 struct thread *thread,
84 			 struct perf_sample *data, int max_stack,
85 			 bool best_effort)
86 {
87 	const struct unwind_libunwind_ops *ops = maps__unwind_libunwind_ops(thread__maps(thread));
88 
89 	if (ops)
90 		return ops->get_entries(cb, arg, thread, data, max_stack, best_effort);
91 	return 0;
92 }
93