[LTP] [PATCH 2/4] lib: Add .modprobe

[Petr Vorel]

Signed-off-by: Petr Vorel <pvorel@suse.cz>
---
 doc/C-Test-API.asciidoc              |  5 +++
 doc/Test-Writing-Guidelines.asciidoc |  1 +
 include/tst_test.h                   |  5 ++-
 lib/tst_test.c                       | 53 ++++++++++++++++++++++++++++
 4 files changed, 63 insertions(+), 1 deletion(-)

diff --git a/doc/C-Test-API.asciidoc b/doc/C-Test-API.asciidoc
index dab811564..f2ba302e2 100644
--- a/doc/C-Test-API.asciidoc
+++ b/doc/C-Test-API.asciidoc
@@ -1609,6 +1609,11 @@ first missing driver.
 The detection is based on reading 'modules.dep' and 'modules.builtin' files
 generated by kmod. The check is skipped on Android.
 
+NULL terminated array '.modprobe' of kernel module names are tried to be loaded
+with 'modprobe' unless they are builtin or already loaded. Test exits with
+'TCONF' on first 'modprobe' non-zero exit. During cleanup are the modules
+loaded by the test unloaded with 'rmmod'.
+
 1.27 Saving & restoring /proc|sys values
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
diff --git a/doc/Test-Writing-Guidelines.asciidoc b/doc/Test-Writing-Guidelines.asciidoc
index 0db852ae6..19487816e 100644
--- a/doc/Test-Writing-Guidelines.asciidoc
+++ b/doc/Test-Writing-Guidelines.asciidoc
@@ -371,6 +371,7 @@ https://github.com/linux-test-project/ltp/wiki/Shell-Test-API[Shell Test API].
 | '.min_mem_avail' | not applicable
 | '.mnt_flags' | 'TST_MNT_PARAMS'
 | '.min_swap_avail' | not applicable
+| '.modprobe' | –
 | '.mntpoint', '.mnt_data' | 'TST_MNTPOINT'
 | '.mount_device' | 'TST_MOUNT_DEVICE'
 | '.needs_cgroup_ctrls' | –
diff --git a/include/tst_test.h b/include/tst_test.h
index 75c2109b9..6b4fac985 100644
--- a/include/tst_test.h
+++ b/include/tst_test.h
@@ -297,9 +297,12 @@ struct tst_test {
 	/* NULL terminated array of resource file names */
 	const char *const *resource_files;
 
-	/* NULL terminated array of needed kernel drivers */
+	/* NULL terminated array of needed kernel drivers to be checked */
 	const char * const *needs_drivers;
 
+	/* NULL terminated array of needed kernel drivers to be loaded with modprobe */
+	const char * const *modprobe;
+
 	/*
 	 * {NULL, NULL} terminated array of (/proc, /sys) files to save
 	 * before setup and restore after cleanup
diff --git a/lib/tst_test.c b/lib/tst_test.c
index 087c62a16..ccbaa4c02 100644
--- a/lib/tst_test.c
+++ b/lib/tst_test.c
@@ -49,6 +49,7 @@ const char *TCID __attribute__((weak));
 #define CVE_DB_URL "https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-"
 
 #define DEFAULT_TIMEOUT 30
+#define MODULES_MAX_LEN 10
 
 struct tst_test *tst_test;
 
@@ -83,6 +84,8 @@ const char *tst_ipc_path = ipc_path;
 
 static char shm_path[1024];
 
+static int modules_loaded[MODULES_MAX_LEN];
+
 int TST_ERR;
 int TST_PASS;
 long TST_RET;
@@ -1135,6 +1138,29 @@ static void do_cgroup_requires(void)
 	tst_cg_init();
 }
 
+/*
+ * Search kernel driver in /proc/modules.
+ *
+ * @param driver The name of the driver.
+ * @return 1 if driver is found, otherwise 0.
+ */
+static int module_loaded(const char *driver)
+{
+	char line[4096];
+	int found = 0;
+	FILE *file = SAFE_FOPEN("/proc/modules", "r");
+
+	while (fgets(line, sizeof(line), file)) {
+		if (strstr(line, driver)) {
+			found = 1;
+			break;
+		}
+	}
+	SAFE_FCLOSE(file);
+
+	return found;
+}
+
 static void do_setup(int argc, char *argv[])
 {
 	if (!tst_test)
@@ -1194,6 +1220,20 @@ static void do_setup(int argc, char *argv[])
 			safe_check_driver(name);
 	}
 
+	if (tst_test->modprobe) {
+		const char *name;
+		int i;
+
+		for (i = 0; (name = tst_test->modprobe[i]); ++i) {
+			/* only load module if not already loaded */
+			if (!module_loaded(name) && tst_check_builtin_driver(name)) {
+				const char *const cmd_modprobe[] = {"modprobe", name, NULL};
+				SAFE_CMD(cmd_modprobe, NULL, NULL);
+				modules_loaded[i] = 1;
+			}
+		}
+	}
+
 	if (tst_test->mount_device)
 		tst_test->format_device = 1;
 
@@ -1362,6 +1402,19 @@ static void do_cleanup(void)
 
 	tst_sys_conf_restore(0);
 
+	if (tst_test->modprobe) {
+		const char *name;
+		int i;
+
+		for (i = 0; (name = tst_test->modprobe[i]); ++i) {
+			if (!modules_loaded[i])
+				continue;
+
+			const char *const cmd_rmmod[] = {"rmmod", name, NULL};
+			SAFE_CMD(cmd_rmmod, NULL, NULL);
+		}
+	}
+
 	if (tst_test->restore_wallclock)
 		tst_wallclock_restore();
 
-- 
2.42.0