X-Git-Url: https://git.lttng.org/?a=blobdiff_plain;f=src%2Fbin%2Flttng-sessiond%2Fshm.c;h=8422230708253fd3a246fc8ec1eb5fdaeada5fe7;hb=a2f8cd58605942314ebf734b3e95c65721e6394a;hp=60a92cd15d3461850e898cdb95c4b00448ef12ba;hpb=cf86ff2c4ababd01fea7ab2c9c289cb7c0a1bcd5;p=lttng-tools.git

diff --git a/src/bin/lttng-sessiond/shm.c b/src/bin/lttng-sessiond/shm.c
index 60a92cd15..842223070 100644
--- a/src/bin/lttng-sessiond/shm.c
+++ b/src/bin/lttng-sessiond/shm.c
@@ -1,19 +1,9 @@
 /*
- * Copyright (C)  2011 - David Goulet <david.goulet@polymtl.ca>
- *                       Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ * Copyright (C) 2011 EfficiOS Inc.
+ * Copyright (C) 2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
  *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License, version 2 only,
- * as published by the Free Software Foundation.
+ * SPDX-License-Identifier: GPL-2.0-only
  *
- * This program 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 General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License along
- * with this program; if not, write to the Free Software Foundation, Inc.,
- * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  */
 
 #define _LGPL_SOURCE
@@ -31,8 +21,7 @@
 #include "shm.h"
 
 /*
- * Using fork to set umask in the child process (not multi-thread safe). We
- * deal with the shm_open vs ftruncate race (happening when the sessiond owns
+ * We deal with the shm_open vs ftruncate race (happening when the sessiond owns
  * the shm and does not let everybody modify it, to ensure safety against
  * shm_unlink) by simply letting the mmap fail and retrying after a few
  * seconds. For global shm, everybody has rw access to it until the sessiond
@@ -41,7 +30,7 @@
 static int get_wait_shm(char *shm_path, size_t mmap_size, int global)
 {
 	int wait_shm_fd, ret;
-	mode_t mode;
+	mode_t mode, old_mode;
 
 	assert(shm_path);
 
@@ -61,11 +50,7 @@ static int get_wait_shm(char *shm_path, size_t mmap_size, int global)
 		mode |= S_IROTH | S_IWOTH;
 	}
 
-	/*
-	 * We're alone in a child process, so we can modify the process-wide
-	 * umask.
-	 */
-	umask(~mode);
+	old_mode = umask(~mode);
 
 	/*
 	 * Try creating shm (or get rw access). We don't do an exclusive open,
@@ -113,7 +98,7 @@ static int get_wait_shm(char *shm_path, size_t mmap_size, int global)
 	ret = ftruncate(wait_shm_fd, mmap_size);
 	if (ret < 0) {
 		PERROR("ftruncate wait shm");
-		exit(EXIT_FAILURE);
+		goto error;
 	}
 
 #ifndef __FreeBSD__
@@ -121,7 +106,7 @@ static int get_wait_shm(char *shm_path, size_t mmap_size, int global)
 		ret = fchown(wait_shm_fd, 0, 0);
 		if (ret < 0) {
 			PERROR("fchown");
-			exit(EXIT_FAILURE);
+			goto error;
 		}
 		/*
 		 * If global session daemon, any application can
@@ -132,13 +117,13 @@ static int get_wait_shm(char *shm_path, size_t mmap_size, int global)
 		ret = fchmod(wait_shm_fd, mode);
 		if (ret < 0) {
 			PERROR("fchmod");
-			exit(EXIT_FAILURE);
+			goto error;
 		}
 	} else {
 		ret = fchown(wait_shm_fd, getuid(), getgid());
 		if (ret < 0) {
 			PERROR("fchown");
-			exit(EXIT_FAILURE);
+			goto error;
 		}
 	}
 #else
@@ -146,13 +131,20 @@ static int get_wait_shm(char *shm_path, size_t mmap_size, int global)
 #endif
 
 	DBG("Got the wait shm fd %d", wait_shm_fd);
-
+end:
+	(void) umask(old_mode);
 	return wait_shm_fd;
 
 error:
 	DBG("Failing to get the wait shm fd");
+	if (wait_shm_fd >= 0) {
+		if (close(wait_shm_fd)) {
+			PERROR("Failed to close wait shm file descriptor during error handling");
+		}
+	}
 
-	return -1;
+	wait_shm_fd = -1;
+	goto end;
 }
 
 /*