From: Julien Desfossez <jdesfossez@efficios.com>
Date: Fri, 1 Dec 2017 19:46:23 +0000 (-0500)
Subject: Make kernel tracer version global to the session daemon
X-Git-Tag: v2.11.0-rc1~373
X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=88076e8986dddbed302570394f9e5589a6b4d923;p=lttng-tools.git

Make kernel tracer version global to the session daemon

A version check is already performed during the initialization of
the kernel tracer. This patch makes the result available as a
global variable in main.c in order to check for support of
the kernel tracer commands required to support the rotation of
sessions.

Signed-off-by: Julien Desfossez <jdesfossez@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
---

diff --git a/src/bin/lttng-sessiond/kernel.c b/src/bin/lttng-sessiond/kernel.c
index 535a5b8e8..35758e3bd 100644
--- a/src/bin/lttng-sessiond/kernel.c
+++ b/src/bin/lttng-sessiond/kernel.c
@@ -824,38 +824,38 @@ error:
 /*
  * Get kernel version and validate it.
  */
-int kernel_validate_version(int tracer_fd)
+int kernel_validate_version(int tracer_fd,
+		struct lttng_kernel_tracer_version *version,
+		struct lttng_kernel_tracer_abi_version *abi_version)
 {
 	int ret;
-	struct lttng_kernel_tracer_version version;
-	struct lttng_kernel_tracer_abi_version abi_version;
 
-	ret = kernctl_tracer_version(tracer_fd, &version);
+	ret = kernctl_tracer_version(tracer_fd, version);
 	if (ret < 0) {
 		ERR("Failed to retrieve the lttng-modules version");
 		goto error;
 	}
 
 	/* Validate version */
-	if (version.major != VERSION_MAJOR) {
+	if (version->major != VERSION_MAJOR) {
 		ERR("Kernel tracer major version (%d) is not compatible with lttng-tools major version (%d)",
-			version.major, VERSION_MAJOR);
+			version->major, VERSION_MAJOR);
 		goto error_version;
 	}
-	ret = kernctl_tracer_abi_version(tracer_fd, &abi_version);
+	ret = kernctl_tracer_abi_version(tracer_fd, abi_version);
 	if (ret < 0) {
 		ERR("Failed to retrieve lttng-modules ABI version");
 		goto error;
 	}
-	if (abi_version.major != LTTNG_MODULES_ABI_MAJOR_VERSION) {
+	if (abi_version->major != LTTNG_MODULES_ABI_MAJOR_VERSION) {
 		ERR("Kernel tracer ABI version (%d.%d) does not match the expected ABI major version (%d.*)",
-			abi_version.major, abi_version.minor,
+			abi_version->major, abi_version->minor,
 			LTTNG_MODULES_ABI_MAJOR_VERSION);
 		goto error;
 	}
 	DBG2("Kernel tracer version validated (%d.%d, ABI %d.%d)",
-			version.major, version.minor,
-			abi_version.major, abi_version.minor);
+			version->major, version->minor,
+			abi_version->major, abi_version->minor);
 	return 0;
 
 error_version:
diff --git a/src/bin/lttng-sessiond/kernel.h b/src/bin/lttng-sessiond/kernel.h
index 1b394947b..17aede1ed 100644
--- a/src/bin/lttng-sessiond/kernel.h
+++ b/src/bin/lttng-sessiond/kernel.h
@@ -54,7 +54,9 @@ int kernel_start_session(struct ltt_kernel_session *session);
 int kernel_stop_session(struct ltt_kernel_session *session);
 ssize_t kernel_list_events(int tracer_fd, struct lttng_event **event_list);
 void kernel_wait_quiescent(int fd);
-int kernel_validate_version(int tracer_fd);
+int kernel_validate_version(int tracer_fd,
+		struct lttng_kernel_tracer_version *kernel_tracer_version,
+		struct lttng_kernel_tracer_abi_version *kernel_tracer_abi_version);
 void kernel_destroy_session(struct ltt_kernel_session *ksess);
 void kernel_destroy_channel(struct ltt_kernel_channel *kchan);
 int kernel_snapshot_record(struct ltt_kernel_session *ksess,
diff --git a/src/bin/lttng-sessiond/main.c b/src/bin/lttng-sessiond/main.c
index 726c4e388..2923664ed 100644
--- a/src/bin/lttng-sessiond/main.c
+++ b/src/bin/lttng-sessiond/main.c
@@ -94,6 +94,9 @@ static int lockfile_fd = -1;
 /* Set to 1 when a SIGUSR1 signal is received. */
 static int recv_child_signal;
 
+static struct lttng_kernel_tracer_version kernel_tracer_version;
+static struct lttng_kernel_tracer_abi_version kernel_tracer_abi_version;
+
 /*
  * Consumer daemon specific control data. Every value not initialized here is
  * set to 0 by the static definition.
@@ -2621,7 +2624,8 @@ static int init_kernel_tracer(void)
 	}
 
 	/* Validate kernel version */
-	ret = kernel_validate_version(kernel_tracer_fd);
+	ret = kernel_validate_version(kernel_tracer_fd, &kernel_tracer_version,
+			&kernel_tracer_abi_version);
 	if (ret < 0) {
 		goto error_version;
 	}