Commit | Line | Data |
---|---|---|
030312cf | 1 | /* |
9d16b343 | 2 | * Copyright (C) 2017 Francis Deslauriers <francis.deslauriers@efficios.com> |
030312cf | 3 | * |
9d16b343 | 4 | * SPDX-License-Identifier: LGPL-2.1-only |
030312cf | 5 | * |
030312cf FD |
6 | */ |
7 | ||
030312cf FD |
8 | #include <fcntl.h> |
9 | #include <stdio.h> | |
10 | #include <sys/syscall.h> | |
11 | #include <unistd.h> | |
12 | ||
13 | #include "utils.h" | |
14 | ||
15 | #define MAX_LEN 16 | |
16 | /* | |
17 | * The process waits for the creation of a file passed as argument from an | |
18 | * external processes to execute a syscall and exiting. This is useful for tests | |
19 | * in combinaison with LTTng's PID tracker feature where we can trace the kernel | |
20 | * events generated by our test process only. | |
21 | */ | |
22 | int main(int argc, char **argv) | |
23 | { | |
c8e51d15 | 24 | int fd, ret; |
030312cf FD |
25 | char buf[MAX_LEN]; |
26 | char *start_file; | |
27 | ||
28 | if (argc != 2) { | |
29 | fprintf(stderr, "Error: Missing argument\n"); | |
30 | fprintf(stderr, "USAGE: %s PATH_WAIT_FILE\n", argv[0]); | |
31 | ret = -1; | |
32 | goto error; | |
33 | } | |
34 | ||
35 | start_file = argv[1]; | |
36 | ||
37 | /* | |
38 | * Wait for the start_file to be created by an external process | |
39 | * (typically the test script) before executing the syscalls. | |
40 | */ | |
41 | ret = wait_on_file(start_file); | |
42 | if (ret != 0) { | |
43 | goto error; | |
44 | } | |
45 | ||
46 | /* | |
47 | * Start generating syscalls. We use syscall(2) to prevent libc to change | |
48 | * the underlying syscall. e.g. calling openat(2) instead of open(2). | |
49 | */ | |
8192bd8f | 50 | fd = syscall(SYS_openat, AT_FDCWD, "/proc/cpuinfo", O_RDONLY); |
030312cf FD |
51 | if (fd < 0) { |
52 | perror("open"); | |
53 | ret = -1; | |
54 | goto error; | |
55 | } | |
56 | ||
57 | ret = syscall(SYS_read, fd, buf, MAX_LEN); | |
58 | if (ret < 0) { | |
59 | perror("read"); | |
60 | ret = -1; | |
61 | goto error; | |
62 | } | |
63 | ||
64 | ret = syscall(SYS_close, fd); | |
65 | if (ret == -1) { | |
66 | perror("close"); | |
67 | ret = -1; | |
68 | goto error; | |
69 | } | |
70 | ||
71 | error: | |
72 | return ret; | |
73 | } |