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
11struct unwind_libunwind_ops __weak *local_unwind_libunwind_ops;
12struct unwind_libunwind_ops __weak *x86_32_unwind_libunwind_ops;
13struct unwind_libunwind_ops __weak *arm64_unwind_libunwind_ops;
14
15int 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(env: 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 }
57out_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
66void 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
74void 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
82int 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

source code of linux/tools/perf/util/unwind-libunwind.c