| 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 | } |