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ba5e8d0a MD |
1 | /* |
2 | * Copyright (C) - 2017 Francis Deslauriers <francis.deslauriers@efficios.com> | |
3 | * Copyright (C) - 2018 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> | |
4 | * | |
5 | * This library is free software; you can redistribute it and/or modify it | |
6 | * under the terms of the GNU Lesser General Public License as published by the | |
7 | * Free Software Foundation; version 2.1 of the License. | |
8 | * | |
9 | * This library is distributed in the hope that it will be useful, but WITHOUT | |
10 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
11 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License | |
12 | * for more details. | |
13 | * | |
14 | * You should have received a copy of the GNU Lesser General Public License | |
15 | * along with this library; if not, write to the Free Software Foundation, | |
16 | * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | |
17 | */ | |
18 | ||
19 | #include <fcntl.h> | |
20 | #include <stdio.h> | |
21 | #include <string.h> | |
22 | #include <sys/stat.h> | |
23 | #include <sys/types.h> | |
24 | #include <unistd.h> | |
25 | ||
26 | #include "utils.h" | |
27 | ||
28 | #define LTTNG_MODULES_FILE "/proc/lttng-test-filter-event" | |
29 | ||
30 | /* | |
31 | * The process waits for the creation of a file passed as argument from an | |
32 | * external processes to execute a syscall and exiting. This is useful for tests | |
33 | * in combinaison with LTTng's PID tracker feature where we can trace the kernel | |
34 | * events generated by our test process only. | |
35 | */ | |
36 | int main(int argc, char **argv) | |
37 | { | |
38 | int fd = -1, ret; | |
39 | char *start_file, *nr_events_str; | |
40 | ssize_t len; | |
41 | ||
42 | if (argc != 3) { | |
43 | fprintf(stderr, "Error: Missing argument\n"); | |
44 | fprintf(stderr, "USAGE: %s PATH_WAIT_FILE NR_EVENTS\n", | |
45 | argv[0]); | |
46 | ret = -1; | |
47 | goto end; | |
48 | } | |
49 | ||
50 | start_file = argv[1]; | |
51 | nr_events_str = argv[2]; | |
52 | ||
53 | /* | |
54 | * Wait for the start_file to be created by an external process | |
55 | * (typically the test script) before executing the syscalls. | |
56 | */ | |
57 | ret = wait_on_file(start_file); | |
58 | if (ret != 0) { | |
59 | goto end; | |
60 | } | |
61 | ||
62 | /* | |
63 | * Start generating events. | |
64 | */ | |
65 | fd = open(LTTNG_MODULES_FILE, O_RDWR); | |
66 | if (fd < 0) { | |
67 | perror("open"); | |
68 | ret = -1; | |
69 | goto end; | |
70 | } | |
71 | ||
72 | len = write(fd, nr_events_str, strlen(nr_events_str) + 1); | |
73 | if (len != strlen(nr_events_str) + 1) { | |
74 | perror("write"); | |
75 | ret = -1; | |
76 | } else { | |
77 | ret = 0; | |
78 | } | |
79 | ||
80 | end: | |
81 | if (fd >= 0) { | |
82 | int closeret = close(fd); | |
83 | if (closeret) { | |
84 | perror("close"); | |
85 | } | |
86 | } | |
87 | return ret; | |
88 | } |