summaryrefslogtreecommitdiffstats
path: root/tools/perf/tests/dwarf-unwind.c
blob: c059ee81c038abd1417c06172274c98d11a9c3ac (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
#include <linux/compiler.h>
#include <sys/types.h>
#include <unistd.h>
#include "tests.h"
#include "debug.h"
#include "machine.h"
#include "event.h"
#include "unwind.h"
#include "perf_regs.h"
#include "map.h"
#include "thread.h"

static int mmap_handler(struct perf_tool *tool __maybe_unused,
			union perf_event *event,
			struct perf_sample *sample __maybe_unused,
			struct machine *machine)
{
	return machine__process_mmap_event(machine, event, NULL);
}

static int init_live_machine(struct machine *machine)
{
	union perf_event event;
	pid_t pid = getpid();

	return perf_event__synthesize_mmap_events(NULL, &event, pid, pid,
						  mmap_handler, machine, true);
}

#define MAX_STACK 6

static int unwind_entry(struct unwind_entry *entry, void *arg)
{
	unsigned long *cnt = (unsigned long *) arg;
	char *symbol = entry->sym ? entry->sym->name : NULL;
	static const char *funcs[MAX_STACK] = {
		"test__arch_unwind_sample",
		"unwind_thread",
		"krava_3",
		"krava_2",
		"krava_1",
		"test__dwarf_unwind"
	};

	if (*cnt >= MAX_STACK) {
		pr_debug("failed: crossed the max stack value %d\n", MAX_STACK);
		return -1;
	}

	if (!symbol) {
		pr_debug("failed: got unresolved address 0x%" PRIx64 "\n",
			 entry->ip);
		return -1;
	}

	pr_debug("got: %s 0x%" PRIx64 "\n", symbol, entry->ip);
	return strcmp((const char *) symbol, funcs[(*cnt)++]);
}

__attribute__ ((noinline))
static int unwind_thread(struct thread *thread, struct machine *machine)
{
	struct perf_sample sample;
	unsigned long cnt = 0;
	int err = -1;

	memset(&sample, 0, sizeof(sample));

	if (test__arch_unwind_sample(&sample, thread)) {
		pr_debug("failed to get unwind sample\n");
		goto out;
	}

	err = unwind__get_entries(unwind_entry, &cnt, machine, thread,
				  &sample, MAX_STACK);
	if (err)
		pr_debug("unwind failed\n");
	else if (cnt != MAX_STACK) {
		pr_debug("got wrong number of stack entries %lu != %d\n",
			 cnt, MAX_STACK);
		err = -1;
	}

 out:
	free(sample.user_stack.data);
	free(sample.user_regs.regs);
	return err;
}

__attribute__ ((noinline))
static int krava_3(struct thread *thread, struct machine *machine)
{
	return unwind_thread(thread, machine);
}

__attribute__ ((noinline))
static int krava_2(struct thread *thread, struct machine *machine)
{
	return krava_3(thread, machine);
}

__attribute__ ((noinline))
static int krava_1(struct thread *thread, struct machine *machine)
{
	return krava_2(thread, machine);
}

int test__dwarf_unwind(void)
{
	struct machines machines;
	struct machine *machine;
	struct thread *thread;
	int err = -1;

	machines__init(&machines);

	machine = machines__find(&machines, HOST_KERNEL_ID);
	if (!machine) {
		pr_err("Could not get machine\n");
		return -1;
	}

	if (init_live_machine(machine)) {
		pr_err("Could not init machine\n");
		goto out;
	}

	if (verbose > 1)
		machine__fprintf(machine, stderr);

	thread = machine__find_thread(machine, getpid(), getpid());
	if (!thread) {
		pr_err("Could not get thread\n");
		goto out;
	}

	err = krava_1(thread, machine);

 out:
	machine__delete_threads(machine);
	machine__exit(machine);
	machines__exit(&machines);
	return err;
}
OpenPOWER on IntegriCloud