From: David Goulet <dgoulet@efficios.com>
Date: Fri, 10 May 2013 17:27:30 +0000 (-0400)
Subject: Fix: check channel subbuf size against page size
X-Git-Tag: v2.2.0-rc3~90
X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=12744796179ed3bfa9c3b6e22bfdeabf2e6081bf;p=lttng-tools.git

Fix: check channel subbuf size against page size

Don't validate channel subbuffer size against the default values but
rather against the lower bound being the page size taken at runtime.

Reported-by: Tan Dung Le Tran <tan.dung.le.tran@ericsson.com>
Signed-off-by: David Goulet <dgoulet@efficios.com>
---

diff --git a/src/bin/lttng-sessiond/channel.c b/src/bin/lttng-sessiond/channel.c
index 8f835fd8b..d826125c9 100644
--- a/src/bin/lttng-sessiond/channel.c
+++ b/src/bin/lttng-sessiond/channel.c
@@ -25,6 +25,7 @@
 #include <common/sessiond-comm/sessiond-comm.h>
 
 #include "channel.h"
+#include "lttng-sessiond.h"
 #include "kernel.h"
 #include "ust-ctl.h"
 #include "utils.h"
@@ -273,6 +274,14 @@ int channel_ust_create(struct ltt_ust_session *usess,
 		goto error;
 	}
 
+	/*
+	 * Invalid subbuffer size if it's lower then the page size.
+	 */
+	if (attr->attr.subbuf_size < page_size) {
+		ret = LTTNG_ERR_INVALID;
+		goto error;
+	}
+
 	if (!attr->attr.num_subbuf ||
 			(attr->attr.num_subbuf & (attr->attr.num_subbuf - 1))) {
 		ret = LTTNG_ERR_INVALID;
@@ -297,18 +306,8 @@ int channel_ust_create(struct ltt_ust_session *usess,
 	/* Validate buffer type. */
 	switch (type) {
 	case LTTNG_BUFFER_PER_PID:
-		if (attr->attr.subbuf_size <
-				default_get_ust_pid_channel_subbuf_size()) {
-			ret = LTTNG_ERR_INVALID;
-			goto error;
-		}
 		break;
 	case LTTNG_BUFFER_PER_UID:
-		if (attr->attr.subbuf_size <
-				default_get_ust_uid_channel_subbuf_size()) {
-			ret = LTTNG_ERR_INVALID;
-			goto error;
-		}
 		break;
 	default:
 		ret = LTTNG_ERR_BUFFER_NOT_SUPPORTED;
diff --git a/src/bin/lttng-sessiond/lttng-sessiond.h b/src/bin/lttng-sessiond/lttng-sessiond.h
index 9258f38a7..a0916c566 100644
--- a/src/bin/lttng-sessiond/lttng-sessiond.h
+++ b/src/bin/lttng-sessiond/lttng-sessiond.h
@@ -71,6 +71,11 @@ struct ust_cmd_queue {
  */
 extern int apps_cmd_notify_pipe[2];
 
+/*
+ * Populated when the daemon starts with the current page size of the system.
+ */
+extern long page_size;
+
 int sessiond_set_thread_pollset(struct lttng_poll_event *events, size_t size);
 int sessiond_check_thread_quit_pipe(int fd, uint32_t events);
 
diff --git a/src/bin/lttng-sessiond/main.c b/src/bin/lttng-sessiond/main.c
index 445485b41..952737138 100644
--- a/src/bin/lttng-sessiond/main.c
+++ b/src/bin/lttng-sessiond/main.c
@@ -232,6 +232,9 @@ static enum consumerd_state kernel_consumerd_state;
  */
 static int app_socket_timeout;
 
+/* Set in main() with the current page size. */
+long page_size;
+
 static
 void setup_consumerd_path(void)
 {
@@ -4038,6 +4041,13 @@ int main(int argc, char **argv)
 
 	setup_consumerd_path();
 
+	page_size = sysconf(_SC_PAGESIZE);
+	if (page_size < 0) {
+		PERROR("sysconf _SC_PAGESIZE");
+		page_size = LONG_MAX;
+		WARN("Fallback page size to %ld", page_size);
+	}
+
 	/* Parse arguments */
 	progname = argv[0];
 	if ((ret = parse_args(argc, argv)) < 0) {