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1// SPDX-License-Identifier: GPL-2.0
2#include <linux/compiler.h>
3#include <linux/types.h>
4#include <linux/zalloc.h>
5#include <inttypes.h>
6#include <limits.h>
7#include <unistd.h>
8#include "tests.h"
9#include "debug.h"
10#include "machine.h"
11#include "event.h"
12#include "../util/unwind.h"
13#include "perf_regs.h"
14#include "map.h"
15#include "symbol.h"
16#include "thread.h"
17#include "callchain.h"
18#include "util/synthetic-events.h"
19
20#if defined (__x86_64__) || defined (__i386__) || defined (__powerpc__)
21#include "arch-tests.h"
22#endif
23
24/* For bsearch. We try to unwind functions in shared object. */
25#include <stdlib.h>
26
27static int mmap_handler(struct perf_tool *tool __maybe_unused,
28 union perf_event *event,
29 struct perf_sample *sample,
30 struct machine *machine)
31{
32 return machine__process_mmap2_event(machine, event, sample);
33}
34
35static int init_live_machine(struct machine *machine)
36{
37 union perf_event event;
38 pid_t pid = getpid();
39
40 return perf_event__synthesize_mmap_events(NULL, &event, pid, pid,
41 mmap_handler, machine, true);
42}
43
44/*
45 * We need to keep these functions global, despite the
46 * fact that they are used only locally in this object,
47 * in order to keep them around even if the binary is
48 * stripped. If they are gone, the unwind check for
49 * symbol fails.
50 */
51int test_dwarf_unwind__thread(struct thread *thread);
52int test_dwarf_unwind__compare(void *p1, void *p2);
53int test_dwarf_unwind__krava_3(struct thread *thread);
54int test_dwarf_unwind__krava_2(struct thread *thread);
55int test_dwarf_unwind__krava_1(struct thread *thread);
56
57#define MAX_STACK 8
58
59static int unwind_entry(struct unwind_entry *entry, void *arg)
60{
61 unsigned long *cnt = (unsigned long *) arg;
62 char *symbol = entry->sym ? entry->sym->name : NULL;
63 static const char *funcs[MAX_STACK] = {
64 "test__arch_unwind_sample",
65 "test_dwarf_unwind__thread",
66 "test_dwarf_unwind__compare",
67 "bsearch",
68 "test_dwarf_unwind__krava_3",
69 "test_dwarf_unwind__krava_2",
70 "test_dwarf_unwind__krava_1",
71 "test__dwarf_unwind"
72 };
73 /*
74 * The funcs[MAX_STACK] array index, based on the
75 * callchain order setup.
76 */
77 int idx = callchain_param.order == ORDER_CALLER ?
78 MAX_STACK - *cnt - 1 : *cnt;
79
80 if (*cnt >= MAX_STACK) {
81 pr_debug("failed: crossed the max stack value %d\n", MAX_STACK);
82 return -1;
83 }
84
85 if (!symbol) {
86 pr_debug("failed: got unresolved address 0x%" PRIx64 "\n",
87 entry->ip);
88 return -1;
89 }
90
91 (*cnt)++;
92 pr_debug("got: %s 0x%" PRIx64 ", expecting %s\n",
93 symbol, entry->ip, funcs[idx]);
94 return strcmp((const char *) symbol, funcs[idx]);
95}
96
97noinline int test_dwarf_unwind__thread(struct thread *thread)
98{
99 struct perf_sample sample;
100 unsigned long cnt = 0;
101 int err = -1;
102
103 memset(&sample, 0, sizeof(sample));
104
105 if (test__arch_unwind_sample(&sample, thread)) {
106 pr_debug("failed to get unwind sample\n");
107 goto out;
108 }
109
110 err = unwind__get_entries(unwind_entry, &cnt, thread,
111 &sample, MAX_STACK);
112 if (err)
113 pr_debug("unwind failed\n");
114 else if (cnt != MAX_STACK) {
115 pr_debug("got wrong number of stack entries %lu != %d\n",
116 cnt, MAX_STACK);
117 err = -1;
118 }
119
120 out:
121 zfree(&sample.user_stack.data);
122 zfree(&sample.user_regs.regs);
123 return err;
124}
125
126static int global_unwind_retval = -INT_MAX;
127
128noinline int test_dwarf_unwind__compare(void *p1, void *p2)
129{
130 /* Any possible value should be 'thread' */
131 struct thread *thread = *(struct thread **)p1;
132
133 if (global_unwind_retval == -INT_MAX) {
134 /* Call unwinder twice for both callchain orders. */
135 callchain_param.order = ORDER_CALLER;
136
137 global_unwind_retval = test_dwarf_unwind__thread(thread);
138 if (!global_unwind_retval) {
139 callchain_param.order = ORDER_CALLEE;
140 global_unwind_retval = test_dwarf_unwind__thread(thread);
141 }
142 }
143
144 return p1 - p2;
145}
146
147noinline int test_dwarf_unwind__krava_3(struct thread *thread)
148{
149 struct thread *array[2] = {thread, thread};
150 void *fp = &bsearch;
151 /*
152 * make _bsearch a volatile function pointer to
153 * prevent potential optimization, which may expand
154 * bsearch and call compare directly from this function,
155 * instead of libc shared object.
156 */
157 void *(*volatile _bsearch)(void *, void *, size_t,
158 size_t, int (*)(void *, void *));
159
160 _bsearch = fp;
161 _bsearch(array, &thread, 2, sizeof(struct thread **),
162 test_dwarf_unwind__compare);
163 return global_unwind_retval;
164}
165
166noinline int test_dwarf_unwind__krava_2(struct thread *thread)
167{
168 return test_dwarf_unwind__krava_3(thread);
169}
170
171noinline int test_dwarf_unwind__krava_1(struct thread *thread)
172{
173 return test_dwarf_unwind__krava_2(thread);
174}
175
176int test__dwarf_unwind(struct test *test __maybe_unused, int subtest __maybe_unused)
177{
178 struct machine *machine;
179 struct thread *thread;
180 int err = -1;
181
182 machine = machine__new_host();
183 if (!machine) {
184 pr_err("Could not get machine\n");
185 return -1;
186 }
187
188 if (machine__create_kernel_maps(machine)) {
189 pr_err("Failed to create kernel maps\n");
190 return -1;
191 }
192
193 callchain_param.record_mode = CALLCHAIN_DWARF;
194 dwarf_callchain_users = true;
195
196 if (init_live_machine(machine)) {
197 pr_err("Could not init machine\n");
198 goto out;
199 }
200
201 if (verbose > 1)
202 machine__fprintf(machine, stderr);
203
204 thread = machine__find_thread(machine, getpid(), getpid());
205 if (!thread) {
206 pr_err("Could not get thread\n");
207 goto out;
208 }
209
210 err = test_dwarf_unwind__krava_1(thread);
211 thread__put(thread);
212
213 out:
214 machine__delete_threads(machine);
215 machine__delete(machine);
216 return err;
217}
1// SPDX-License-Identifier: GPL-2.0
2#include <linux/compiler.h>
3#include <linux/types.h>
4#include <linux/zalloc.h>
5#include <inttypes.h>
6#include <limits.h>
7#include <unistd.h>
8#include "tests.h"
9#include "debug.h"
10#include "machine.h"
11#include "event.h"
12#include "../util/unwind.h"
13#include "perf_regs.h"
14#include "map.h"
15#include "symbol.h"
16#include "thread.h"
17#include "callchain.h"
18#include "util/synthetic-events.h"
19
20#if defined (__x86_64__) || defined (__i386__) || defined (__powerpc__)
21#include "arch-tests.h"
22#endif
23
24/* For bsearch. We try to unwind functions in shared object. */
25#include <stdlib.h>
26
27static int mmap_handler(struct perf_tool *tool __maybe_unused,
28 union perf_event *event,
29 struct perf_sample *sample,
30 struct machine *machine)
31{
32 return machine__process_mmap2_event(machine, event, sample);
33}
34
35static int init_live_machine(struct machine *machine)
36{
37 union perf_event event;
38 pid_t pid = getpid();
39
40 memset(&event, 0, sizeof(event));
41 return perf_event__synthesize_mmap_events(NULL, &event, pid, pid,
42 mmap_handler, machine, true);
43}
44
45/*
46 * We need to keep these functions global, despite the
47 * fact that they are used only locally in this object,
48 * in order to keep them around even if the binary is
49 * stripped. If they are gone, the unwind check for
50 * symbol fails.
51 */
52int test_dwarf_unwind__thread(struct thread *thread);
53int test_dwarf_unwind__compare(void *p1, void *p2);
54int test_dwarf_unwind__krava_3(struct thread *thread);
55int test_dwarf_unwind__krava_2(struct thread *thread);
56int test_dwarf_unwind__krava_1(struct thread *thread);
57
58#define MAX_STACK 8
59
60static int unwind_entry(struct unwind_entry *entry, void *arg)
61{
62 unsigned long *cnt = (unsigned long *) arg;
63 char *symbol = entry->ms.sym ? entry->ms.sym->name : NULL;
64 static const char *funcs[MAX_STACK] = {
65 "test__arch_unwind_sample",
66 "test_dwarf_unwind__thread",
67 "test_dwarf_unwind__compare",
68 "bsearch",
69 "test_dwarf_unwind__krava_3",
70 "test_dwarf_unwind__krava_2",
71 "test_dwarf_unwind__krava_1",
72 "test__dwarf_unwind"
73 };
74 /*
75 * The funcs[MAX_STACK] array index, based on the
76 * callchain order setup.
77 */
78 int idx = callchain_param.order == ORDER_CALLER ?
79 MAX_STACK - *cnt - 1 : *cnt;
80
81 if (*cnt >= MAX_STACK) {
82 pr_debug("failed: crossed the max stack value %d\n", MAX_STACK);
83 return -1;
84 }
85
86 if (!symbol) {
87 pr_debug("failed: got unresolved address 0x%" PRIx64 "\n",
88 entry->ip);
89 return -1;
90 }
91
92 (*cnt)++;
93 pr_debug("got: %s 0x%" PRIx64 ", expecting %s\n",
94 symbol, entry->ip, funcs[idx]);
95 return strcmp((const char *) symbol, funcs[idx]);
96}
97
98__no_tail_call noinline int test_dwarf_unwind__thread(struct thread *thread)
99{
100 struct perf_sample sample;
101 unsigned long cnt = 0;
102 int err = -1;
103
104 memset(&sample, 0, sizeof(sample));
105
106 if (test__arch_unwind_sample(&sample, thread)) {
107 pr_debug("failed to get unwind sample\n");
108 goto out;
109 }
110
111 err = unwind__get_entries(unwind_entry, &cnt, thread,
112 &sample, MAX_STACK);
113 if (err)
114 pr_debug("unwind failed\n");
115 else if (cnt != MAX_STACK) {
116 pr_debug("got wrong number of stack entries %lu != %d\n",
117 cnt, MAX_STACK);
118 err = -1;
119 }
120
121 out:
122 zfree(&sample.user_stack.data);
123 zfree(&sample.user_regs.regs);
124 return err;
125}
126
127static int global_unwind_retval = -INT_MAX;
128
129__no_tail_call noinline int test_dwarf_unwind__compare(void *p1, void *p2)
130{
131 /* Any possible value should be 'thread' */
132 struct thread *thread = *(struct thread **)p1;
133
134 if (global_unwind_retval == -INT_MAX) {
135 /* Call unwinder twice for both callchain orders. */
136 callchain_param.order = ORDER_CALLER;
137
138 global_unwind_retval = test_dwarf_unwind__thread(thread);
139 if (!global_unwind_retval) {
140 callchain_param.order = ORDER_CALLEE;
141 global_unwind_retval = test_dwarf_unwind__thread(thread);
142 }
143 }
144
145 return p1 - p2;
146}
147
148__no_tail_call noinline int test_dwarf_unwind__krava_3(struct thread *thread)
149{
150 struct thread *array[2] = {thread, thread};
151 void *fp = &bsearch;
152 /*
153 * make _bsearch a volatile function pointer to
154 * prevent potential optimization, which may expand
155 * bsearch and call compare directly from this function,
156 * instead of libc shared object.
157 */
158 void *(*volatile _bsearch)(void *, void *, size_t,
159 size_t, int (*)(void *, void *));
160
161 _bsearch = fp;
162 _bsearch(array, &thread, 2, sizeof(struct thread **),
163 test_dwarf_unwind__compare);
164 return global_unwind_retval;
165}
166
167__no_tail_call noinline int test_dwarf_unwind__krava_2(struct thread *thread)
168{
169 return test_dwarf_unwind__krava_3(thread);
170}
171
172__no_tail_call noinline int test_dwarf_unwind__krava_1(struct thread *thread)
173{
174 return test_dwarf_unwind__krava_2(thread);
175}
176
177int test__dwarf_unwind(struct test *test __maybe_unused, int subtest __maybe_unused)
178{
179 struct machine *machine;
180 struct thread *thread;
181 int err = -1;
182
183 machine = machine__new_host();
184 if (!machine) {
185 pr_err("Could not get machine\n");
186 return -1;
187 }
188
189 if (machine__create_kernel_maps(machine)) {
190 pr_err("Failed to create kernel maps\n");
191 return -1;
192 }
193
194 callchain_param.record_mode = CALLCHAIN_DWARF;
195 dwarf_callchain_users = true;
196
197 if (init_live_machine(machine)) {
198 pr_err("Could not init machine\n");
199 goto out;
200 }
201
202 if (verbose > 1)
203 machine__fprintf(machine, stderr);
204
205 thread = machine__find_thread(machine, getpid(), getpid());
206 if (!thread) {
207 pr_err("Could not get thread\n");
208 goto out;
209 }
210
211 err = test_dwarf_unwind__krava_1(thread);
212 thread__put(thread);
213
214 out:
215 machine__delete_threads(machine);
216 machine__delete(machine);
217 return err;
218}