From: Francis Deslauriers <francis.deslauriers@efficios.com>
Date: Wed, 5 Apr 2017 15:53:51 +0000 (-0400)
Subject: Tests: Add test app to generate syscalls
X-Git-Url: http://git.efficios.com/?p=lttng-tools.git;a=commitdiff_plain;h=030312cfdeb643db807b028f9edffdee57384416

Tests: Add test app to generate syscalls

This app launches and waits for the creation of a file specified in the
arguments before executing syscalls. This can be used with the PID
tracker feature of LTTng to only trace the syscalls made by the test
process and thus makes the tests more reliable.

Signed-off-by: Francis Deslauriers <francis.deslauriers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
---

diff --git a/.gitignore b/.gitignore
index c9927d248..7600cf6d5 100644
--- a/.gitignore
+++ b/.gitignore
@@ -111,6 +111,7 @@ health_check
 /tests/regression/ust/ust-dl/test_ust-dl
 /tests/utils/testapp/gen-ust-nevents/gen-ust-nevents
 /tests/utils/testapp/gen-ust-tracef/gen-ust-tracef
+/tests/utils/testapp/gen-syscall-events/gen-syscall-events
 /tests/regression/tools/live/live_test
 /tests/unit/ini_config/ini_config
 /tests/perf/find_event
diff --git a/configure.ac b/configure.ac
index b6ea39c55..972a73e8b 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1117,6 +1117,7 @@ AC_CONFIG_FILES([
 	tests/utils/testapp/gen-ust-events/Makefile
 	tests/utils/testapp/gen-ust-nevents/Makefile
 	tests/utils/testapp/gen-ust-nevents-str/Makefile
+	tests/utils/testapp/gen-syscall-events/Makefile
 	tests/utils/testapp/gen-ust-tracef/Makefile
 ])
 
diff --git a/tests/utils/testapp/Makefile.am b/tests/utils/testapp/Makefile.am
index 036561e30..596591265 100644
--- a/tests/utils/testapp/Makefile.am
+++ b/tests/utils/testapp/Makefile.am
@@ -1,3 +1,3 @@
-SUBDIRS = gen-ust-events gen-ust-nevents gen-ust-nevents-str gen-ust-tracef
+SUBDIRS = gen-ust-events gen-ust-nevents gen-ust-nevents-str gen-ust-tracef gen-syscall-events
 
 noinst_HEADERS = signal-helper.h
diff --git a/tests/utils/testapp/gen-syscall-events/Makefile.am b/tests/utils/testapp/gen-syscall-events/Makefile.am
new file mode 100644
index 000000000..9741b1818
--- /dev/null
+++ b/tests/utils/testapp/gen-syscall-events/Makefile.am
@@ -0,0 +1,5 @@
+AM_CFLAGS += -I$(top_srcdir)/tests/utils/
+
+noinst_PROGRAMS = gen-syscall-events
+gen_syscall_events_SOURCES = gen-syscall-events.c
+gen_syscall_events_LDADD = $(top_builddir)/tests/utils/libtestutils.la
diff --git a/tests/utils/testapp/gen-syscall-events/gen-syscall-events.c b/tests/utils/testapp/gen-syscall-events/gen-syscall-events.c
new file mode 100644
index 000000000..5e4aabe58
--- /dev/null
+++ b/tests/utils/testapp/gen-syscall-events/gen-syscall-events.c
@@ -0,0 +1,85 @@
+/*
+ * Copyright (C) - 2017 Francis Deslauriers <francis.deslauriers@efficios.com>
+ *
+ * This library is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation; version 2.1 of the License.
+ *
+ * This library is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this library; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA
+ */
+
+#define _LGPL_SOURCE
+
+#include <fcntl.h>
+#include <stdio.h>
+#include <sys/syscall.h>
+#include <unistd.h>
+
+#include "utils.h"
+
+#define MAX_LEN 16
+/*
+ * The process waits for the creation of a file passed as argument from an
+ * external processes to execute a syscall and exiting. This is useful for tests
+ * in combinaison with LTTng's PID tracker feature where we can trace the kernel
+ * events generated by our test process only.
+ */
+int main(int argc, char **argv)
+{
+	int fd, ret = 0;
+	char buf[MAX_LEN];
+	char *start_file;
+
+	if (argc != 2) {
+		fprintf(stderr, "Error: Missing argument\n");
+		fprintf(stderr, "USAGE: %s PATH_WAIT_FILE\n", argv[0]);
+		ret = -1;
+		goto error;
+	}
+
+	start_file = argv[1];
+
+	/*
+	 * Wait for the start_file to be created by an external process
+	 * (typically the test script) before executing the syscalls.
+	 */
+	ret = wait_on_file(start_file);
+	if (ret != 0) {
+		goto error;
+	}
+
+	/*
+	 * Start generating syscalls. We use syscall(2) to prevent libc to change
+	 * the underlying syscall. e.g. calling openat(2) instead of open(2).
+	 */
+	fd = syscall(SYS_open, "/proc/cpuinfo", O_RDONLY);
+	if (fd < 0) {
+		perror("open");
+		ret = -1;
+		goto error;
+	}
+
+	ret = syscall(SYS_read, fd, buf, MAX_LEN);
+	if (ret < 0) {
+		perror("read");
+		ret = -1;
+		goto error;
+	}
+
+	ret = syscall(SYS_close, fd);
+	if (ret == -1) {
+		perror("close");
+		ret = -1;
+		goto error;
+	}
+
+error:
+	return ret;
+}