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1#include <linux/compiler.h>
2#include <sys/types.h>
3#include <unistd.h>
4#include "tests.h"
5#include "debug.h"
6#include "machine.h"
7#include "event.h"
8#include "unwind.h"
9#include "perf_regs.h"
10#include "map.h"
11#include "thread.h"
12
13static int mmap_handler(struct perf_tool *tool __maybe_unused,
14 union perf_event *event,
15 struct perf_sample *sample __maybe_unused,
16 struct machine *machine)
17{
18 return machine__process_mmap_event(machine, event, NULL);
19}
20
21static int init_live_machine(struct machine *machine)
22{
23 union perf_event event;
24 pid_t pid = getpid();
25
26 return perf_event__synthesize_mmap_events(NULL, &event, pid, pid,
27 mmap_handler, machine, true);
28}
29
30#define MAX_STACK 6
31
32static int unwind_entry(struct unwind_entry *entry, void *arg)
33{
34 unsigned long *cnt = (unsigned long *) arg;
35 char *symbol = entry->sym ? entry->sym->name : NULL;
36 static const char *funcs[MAX_STACK] = {
37 "test__arch_unwind_sample",
38 "unwind_thread",
39 "krava_3",
40 "krava_2",
41 "krava_1",
42 "test__dwarf_unwind"
43 };
44
45 if (*cnt >= MAX_STACK) {
46 pr_debug("failed: crossed the max stack value %d\n", MAX_STACK);
47 return -1;
48 }
49
50 if (!symbol) {
51 pr_debug("failed: got unresolved address 0x%" PRIx64 "\n",
52 entry->ip);
53 return -1;
54 }
55
56 pr_debug("got: %s 0x%" PRIx64 "\n", symbol, entry->ip);
57 return strcmp((const char *) symbol, funcs[(*cnt)++]);
58}
59
60__attribute__ ((noinline))
61static int unwind_thread(struct thread *thread, struct machine *machine)
62{
63 struct perf_sample sample;
64 unsigned long cnt = 0;
65 int err = -1;
66
67 memset(&sample, 0, sizeof(sample));
68
69 if (test__arch_unwind_sample(&sample, thread)) {
70 pr_debug("failed to get unwind sample\n");
71 goto out;
72 }
73
74 err = unwind__get_entries(unwind_entry, &cnt, machine, thread,
75 &sample, MAX_STACK);
76 if (err)
77 pr_debug("unwind failed\n");
78 else if (cnt != MAX_STACK) {
79 pr_debug("got wrong number of stack entries %lu != %d\n",
80 cnt, MAX_STACK);
81 err = -1;
82 }
83
84 out:
85 free(sample.user_stack.data);
86 free(sample.user_regs.regs);
87 return err;
88}
89
90__attribute__ ((noinline))
91static int krava_3(struct thread *thread, struct machine *machine)
92{
93 return unwind_thread(thread, machine);
94}
95
96__attribute__ ((noinline))
97static int krava_2(struct thread *thread, struct machine *machine)
98{
99 return krava_3(thread, machine);
100}
101
102__attribute__ ((noinline))
103static int krava_1(struct thread *thread, struct machine *machine)
104{
105 return krava_2(thread, machine);
106}
107
108int test__dwarf_unwind(void)
109{
110 struct machines machines;
111 struct machine *machine;
112 struct thread *thread;
113 int err = -1;
114
115 machines__init(&machines);
116
117 machine = machines__find(&machines, HOST_KERNEL_ID);
118 if (!machine) {
119 pr_err("Could not get machine\n");
120 return -1;
121 }
122
123 if (init_live_machine(machine)) {
124 pr_err("Could not init machine\n");
125 goto out;
126 }
127
128 if (verbose > 1)
129 machine__fprintf(machine, stderr);
130
131 thread = machine__find_thread(machine, getpid(), getpid());
132 if (!thread) {
133 pr_err("Could not get thread\n");
134 goto out;
135 }
136
137 err = krava_1(thread, machine);
138
139 out:
140 machine__delete_threads(machine);
141 machine__exit(machine);
142 machines__exit(&machines);
143 return err;
144}
1#include <linux/compiler.h>
2#include <linux/types.h>
3#include <unistd.h>
4#include "tests.h"
5#include "debug.h"
6#include "machine.h"
7#include "event.h"
8#include "unwind.h"
9#include "perf_regs.h"
10#include "map.h"
11#include "thread.h"
12#include "callchain.h"
13
14#if defined (__x86_64__) || defined (__i386__)
15#include "arch-tests.h"
16#endif
17
18/* For bsearch. We try to unwind functions in shared object. */
19#include <stdlib.h>
20
21static int mmap_handler(struct perf_tool *tool __maybe_unused,
22 union perf_event *event,
23 struct perf_sample *sample,
24 struct machine *machine)
25{
26 return machine__process_mmap2_event(machine, event, sample);
27}
28
29static int init_live_machine(struct machine *machine)
30{
31 union perf_event event;
32 pid_t pid = getpid();
33
34 return perf_event__synthesize_mmap_events(NULL, &event, pid, pid,
35 mmap_handler, machine, true, 500);
36}
37
38#define MAX_STACK 8
39
40static int unwind_entry(struct unwind_entry *entry, void *arg)
41{
42 unsigned long *cnt = (unsigned long *) arg;
43 char *symbol = entry->sym ? entry->sym->name : NULL;
44 static const char *funcs[MAX_STACK] = {
45 "test__arch_unwind_sample",
46 "unwind_thread",
47 "compare",
48 "bsearch",
49 "krava_3",
50 "krava_2",
51 "krava_1",
52 "test__dwarf_unwind"
53 };
54 /*
55 * The funcs[MAX_STACK] array index, based on the
56 * callchain order setup.
57 */
58 int idx = callchain_param.order == ORDER_CALLER ?
59 MAX_STACK - *cnt - 1 : *cnt;
60
61 if (*cnt >= MAX_STACK) {
62 pr_debug("failed: crossed the max stack value %d\n", MAX_STACK);
63 return -1;
64 }
65
66 if (!symbol) {
67 pr_debug("failed: got unresolved address 0x%" PRIx64 "\n",
68 entry->ip);
69 return -1;
70 }
71
72 (*cnt)++;
73 pr_debug("got: %s 0x%" PRIx64 ", expecting %s\n",
74 symbol, entry->ip, funcs[idx]);
75 return strcmp((const char *) symbol, funcs[idx]);
76}
77
78__attribute__ ((noinline))
79static int unwind_thread(struct thread *thread)
80{
81 struct perf_sample sample;
82 unsigned long cnt = 0;
83 int err = -1;
84
85 memset(&sample, 0, sizeof(sample));
86
87 if (test__arch_unwind_sample(&sample, thread)) {
88 pr_debug("failed to get unwind sample\n");
89 goto out;
90 }
91
92 err = unwind__get_entries(unwind_entry, &cnt, thread,
93 &sample, MAX_STACK);
94 if (err)
95 pr_debug("unwind failed\n");
96 else if (cnt != MAX_STACK) {
97 pr_debug("got wrong number of stack entries %lu != %d\n",
98 cnt, MAX_STACK);
99 err = -1;
100 }
101
102 out:
103 free(sample.user_stack.data);
104 free(sample.user_regs.regs);
105 return err;
106}
107
108static int global_unwind_retval = -INT_MAX;
109
110__attribute__ ((noinline))
111static int compare(void *p1, void *p2)
112{
113 /* Any possible value should be 'thread' */
114 struct thread *thread = *(struct thread **)p1;
115
116 if (global_unwind_retval == -INT_MAX) {
117 /* Call unwinder twice for both callchain orders. */
118 callchain_param.order = ORDER_CALLER;
119
120 global_unwind_retval = unwind_thread(thread);
121 if (!global_unwind_retval) {
122 callchain_param.order = ORDER_CALLEE;
123 global_unwind_retval = unwind_thread(thread);
124 }
125 }
126
127 return p1 - p2;
128}
129
130__attribute__ ((noinline))
131static int krava_3(struct thread *thread)
132{
133 struct thread *array[2] = {thread, thread};
134 void *fp = &bsearch;
135 /*
136 * make _bsearch a volatile function pointer to
137 * prevent potential optimization, which may expand
138 * bsearch and call compare directly from this function,
139 * instead of libc shared object.
140 */
141 void *(*volatile _bsearch)(void *, void *, size_t,
142 size_t, int (*)(void *, void *));
143
144 _bsearch = fp;
145 _bsearch(array, &thread, 2, sizeof(struct thread **), compare);
146 return global_unwind_retval;
147}
148
149__attribute__ ((noinline))
150static int krava_2(struct thread *thread)
151{
152 return krava_3(thread);
153}
154
155__attribute__ ((noinline))
156static int krava_1(struct thread *thread)
157{
158 return krava_2(thread);
159}
160
161int test__dwarf_unwind(int subtest __maybe_unused)
162{
163 struct machine *machine;
164 struct thread *thread;
165 int err = -1;
166
167 machine = machine__new_host();
168 if (!machine) {
169 pr_err("Could not get machine\n");
170 return -1;
171 }
172
173 if (machine__create_kernel_maps(machine)) {
174 pr_err("Failed to create kernel maps\n");
175 return -1;
176 }
177
178 callchain_param.record_mode = CALLCHAIN_DWARF;
179
180 if (init_live_machine(machine)) {
181 pr_err("Could not init machine\n");
182 goto out;
183 }
184
185 if (verbose > 1)
186 machine__fprintf(machine, stderr);
187
188 thread = machine__find_thread(machine, getpid(), getpid());
189 if (!thread) {
190 pr_err("Could not get thread\n");
191 goto out;
192 }
193
194 err = krava_1(thread);
195 thread__put(thread);
196
197 out:
198 machine__delete_threads(machine);
199 machine__delete(machine);
200 return err;
201}