| 1 | /* |
| 2 | * Copyright (C) 2017 Francis Deslauriers <francis.deslauriers@efficios.com> |
| 3 | * Copyright (C) 2018 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
| 4 | * |
| 5 | * SPDX-License-Identifier: LGPL-2.1-only |
| 6 | * |
| 7 | */ |
| 8 | |
| 9 | #include "utils.h" |
| 10 | |
| 11 | #include <fcntl.h> |
| 12 | #include <stdio.h> |
| 13 | #include <string.h> |
| 14 | #include <sys/stat.h> |
| 15 | #include <sys/types.h> |
| 16 | #include <unistd.h> |
| 17 | |
| 18 | #define LTTNG_MODULES_FILE "/proc/lttng-test-filter-event" |
| 19 | |
| 20 | /* |
| 21 | * The process waits for the creation of a file passed as argument from an |
| 22 | * external processes to execute a syscall and exiting. This is useful for tests |
| 23 | * in combinaison with LTTng's PID tracker feature where we can trace the kernel |
| 24 | * events generated by our test process only. |
| 25 | */ |
| 26 | int main(int argc, char **argv) |
| 27 | { |
| 28 | int fd = -1, ret; |
| 29 | char *start_file, *nr_events_str; |
| 30 | ssize_t len; |
| 31 | |
| 32 | if (argc != 3) { |
| 33 | fprintf(stderr, "Error: Missing argument\n"); |
| 34 | fprintf(stderr, "USAGE: %s PATH_WAIT_FILE NR_EVENTS\n", argv[0]); |
| 35 | ret = -1; |
| 36 | goto end; |
| 37 | } |
| 38 | |
| 39 | start_file = argv[1]; |
| 40 | nr_events_str = argv[2]; |
| 41 | |
| 42 | /* |
| 43 | * Wait for the start_file to be created by an external process |
| 44 | * (typically the test script) before executing the syscalls. |
| 45 | */ |
| 46 | ret = wait_on_file(start_file); |
| 47 | if (ret != 0) { |
| 48 | goto end; |
| 49 | } |
| 50 | |
| 51 | /* |
| 52 | * Start generating events. |
| 53 | */ |
| 54 | fd = open(LTTNG_MODULES_FILE, O_RDWR); |
| 55 | if (fd < 0) { |
| 56 | perror("open"); |
| 57 | ret = -1; |
| 58 | goto end; |
| 59 | } |
| 60 | |
| 61 | len = write(fd, nr_events_str, strlen(nr_events_str) + 1); |
| 62 | if (len != (ssize_t) strlen(nr_events_str) + 1) { |
| 63 | perror("write"); |
| 64 | ret = -1; |
| 65 | } else { |
| 66 | ret = 0; |
| 67 | } |
| 68 | |
| 69 | end: |
| 70 | if (fd >= 0) { |
| 71 | int closeret = close(fd); |
| 72 | if (closeret) { |
| 73 | perror("close"); |
| 74 | } |
| 75 | } |
| 76 | return ret; |
| 77 | } |