summaryrefslogtreecommitdiff
path: root/samples/bpf/tracex2_user.c
blob: cd0241c1447a5fb37d0e9e1633f4a47a457f344f (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 <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <signal.h>
#include <linux/bpf.h>
#include <string.h>
#include "libbpf.h"
#include "bpf_load.h"

#define MAX_INDEX	64
#define MAX_STARS	38

static void stars(char *str, long val, long max, int width)
{
	int i;

	for (i = 0; i < (width * val / max) - 1 && i < width - 1; i++)
		str[i] = '*';
	if (val > max)
		str[i - 1] = '+';
	str[i] = '\0';
}

struct task {
	char comm[16];
	__u64 pid_tgid;
	__u64 uid_gid;
};

struct hist_key {
	struct task t;
	__u32 index;
};

#define SIZE sizeof(struct task)

static void print_hist_for_pid(int fd, void *task)
{
	struct hist_key key = {}, next_key;
	char starstr[MAX_STARS];
	long value;
	long data[MAX_INDEX] = {};
	int max_ind = -1;
	long max_value = 0;
	int i, ind;

	while (bpf_get_next_key(fd, &key, &next_key) == 0) {
		if (memcmp(&next_key, task, SIZE)) {
			key = next_key;
			continue;
		}
		bpf_lookup_elem(fd, &next_key, &value);
		ind = next_key.index;
		data[ind] = value;
		if (value && ind > max_ind)
			max_ind = ind;
		if (value > max_value)
			max_value = value;
		key = next_key;
	}

	printf("           syscall write() stats\n");
	printf("     byte_size       : count     distribution\n");
	for (i = 1; i <= max_ind + 1; i++) {
		stars(starstr, data[i - 1], max_value, MAX_STARS);
		printf("%8ld -> %-8ld : %-8ld |%-*s|\n",
		       (1l << i) >> 1, (1l << i) - 1, data[i - 1],
		       MAX_STARS, starstr);
	}
}

static void print_hist(int fd)
{
	struct hist_key key = {}, next_key;
	static struct task tasks[1024];
	int task_cnt = 0;
	int i;

	while (bpf_get_next_key(fd, &key, &next_key) == 0) {
		int found = 0;

		for (i = 0; i < task_cnt; i++)
			if (memcmp(&tasks[i], &next_key, SIZE) == 0)
				found = 1;
		if (!found)
			memcpy(&tasks[task_cnt++], &next_key, SIZE);
		key = next_key;
	}

	for (i = 0; i < task_cnt; i++) {
		printf("\npid %d cmd %s uid %d\n",
		       (__u32) tasks[i].pid_tgid,
		       tasks[i].comm,
		       (__u32) tasks[i].uid_gid);
		print_hist_for_pid(fd, &tasks[i]);
	}

}

static void int_exit(int sig)
{
	print_hist(map_fd[1]);
	exit(0);
}

int main(int ac, char **argv)
{
	char filename[256];
	long key, next_key, value;
	FILE *f;
	int i;

	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);

	signal(SIGINT, int_exit);

	/* start 'ping' in the background to have some kfree_skb events */
	f = popen("ping -c5 localhost", "r");
	(void) f;

	/* start 'dd' in the background to have plenty of 'write' syscalls */
	f = popen("dd if=/dev/zero of=/dev/null count=5000000", "r");
	(void) f;

	if (load_bpf_file(filename)) {
		printf("%s", bpf_log_buf);
		return 1;
	}

	for (i = 0; i < 5; i++) {
		key = 0;
		while (bpf_get_next_key(map_fd[0], &key, &next_key) == 0) {
			bpf_lookup_elem(map_fd[0], &next_key, &value);
			printf("location 0x%lx count %ld\n", next_key, value);
			key = next_key;
		}
		if (key)
			printf("\n");
		sleep(1);
	}
	print_hist(map_fd[1]);

	return 0;
}