Fix: pass private data to context callbacks

[lttng-ust.git] / liblttng-ust / getenv.h

diff --git a/liblttng-ust/getenv.h b/liblttng-ust/getenv.h
index 05864fb8eb39b5c79ef3cdae2e31118f9edf7165..61d4919378c44e0410bc54e4a72b3e16007cc3bf 100644 (file)
--- a/liblttng-ust/getenv.h
+++ b/liblttng-ust/getenv.h
@@ -1,44 +1,25 @@
+/*
+ * SPDX-License-Identifier: LGPL-2.1-only
+ *
+ * Copyright (C) 2015 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ */
+
 #ifndef _COMPAT_GETENV_H
 #define _COMPAT_GETENV_H
 
 /*
- * Copyright (C) 2015 - Mathieu Desnoyers <mathieu.desnoyers@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; only
- * 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
+ * Always add the lttng-ust environment variables using the lttng_ust_getenv()
+ * infrastructure rather than using getenv() directly.  This ensures that we
+ * don't trigger races between getenv() invoked by lttng-ust listener threads
+ * invoked concurrently with setenv() called by an otherwise single-threaded
+ * application thread. (the application is not aware that it runs with
+ * lttng-ust)
  */
 
-#include <stdlib.h>
-#include <unistd.h>
-#include <sys/types.h>
-#include <usterr-signal-safe.h>
-
-static inline
-int lttng_is_setuid_setgid(void)
-{
-       return geteuid() != getuid() || getegid() != getgid();
-}
+char *lttng_ust_getenv(const char *name)
+       __attribute__((visibility("hidden")));
 
-static inline
-char *lttng_secure_getenv(const char *name)
-{
-       if (lttng_is_setuid_setgid()) {
-               ERR("Getting environment variable '%s' from setuid/setgid binary refused for security reasons.",
-                       name);
-               return NULL;
-       }
-       return getenv(name);
-}
+void lttng_ust_getenv_init(void)
+       __attribute__((visibility("hidden")));
 
 #endif /* _COMPAT_GETENV_H */