From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Date: Sun, 12 Nov 2017 19:51:24 +0000 (-0500)
Subject: Fix: ensure fd tracker is initialized when called from constructors
X-Git-Tag: v2.11.0-rc1~31
X-Git-Url: http://git.liburcu.org/?p=lttng-ust.git;a=commitdiff_plain;h=7d34f27dce903a88241e96787c1f900b6ea08245

Fix: ensure fd tracker is initialized when called from constructors

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
---

diff --git a/liblttng-ust-comm/lttng-ust-fd-tracker.c b/liblttng-ust-comm/lttng-ust-fd-tracker.c
index d56288e3..8d2acb69 100644
--- a/liblttng-ust-comm/lttng-ust-fd-tracker.c
+++ b/liblttng-ust-comm/lttng-ust-fd-tracker.c
@@ -34,6 +34,7 @@
 #include <pthread.h>
 #include <urcu/compiler.h>
 #include <urcu/tls-compat.h>
+#include <urcu/system.h>
 
 #include <ust-fd.h>
 #include <helper.h>
@@ -71,6 +72,7 @@ static DEFINE_URCU_TLS(int, thread_fd_tracking);
 static fd_set *lttng_fd_set;
 static int lttng_ust_max_fd;
 static int num_fd_sets;
+static int init_done;
 
 /*
  * Force a read (imply TLS fixup for dlopen) of TLS variables.
@@ -90,6 +92,9 @@ void lttng_ust_init_fd_tracker(void)
 	struct rlimit rlim;
 	int i;
 
+	if (CMM_LOAD_SHARED(init_done))
+		return;
+
 	memset(&rlim, 0, sizeof(rlim));
 	/* Get the current possible max number of fd for this process. */
 	if (getrlimit(RLIMIT_NOFILE, &rlim) < 0)
@@ -113,6 +118,7 @@ void lttng_ust_init_fd_tracker(void)
 		abort();
 	for (i = 0; i < num_fd_sets; i++)
 		FD_ZERO((&lttng_fd_set[i]));
+	CMM_STORE_SHARED(init_done, 1);
 }
 
 void lttng_ust_lock_fd_tracker(void)
@@ -143,6 +149,12 @@ void lttng_ust_unlock_fd_tracker(void)
  */
 void lttng_ust_add_fd_to_tracker(int fd)
 {
+	/*
+	 * Ensure the tracker is initialized when called from
+	 * constructors.
+	 */
+	lttng_ust_init_fd_tracker();
+
 	assert(URCU_TLS(thread_fd_tracking));
 	/* Trying to add an fd which we can not accommodate. */
 	assert(IS_FD_VALID(fd));
@@ -158,6 +170,12 @@ void lttng_ust_add_fd_to_tracker(int fd)
  */
 void lttng_ust_delete_fd_from_tracker(int fd)
 {
+	/*
+	 * Ensure the tracker is initialized when called from
+	 * constructors.
+	 */
+	lttng_ust_init_fd_tracker();
+
 	assert(URCU_TLS(thread_fd_tracking));
 	/* Not a valid fd. */
 	assert(IS_FD_VALID(fd));
@@ -178,6 +196,12 @@ int lttng_ust_safe_close_fd(int fd, int (*close_cb)(int fd))
 
 	lttng_ust_fixup_fd_tracker_tls();
 
+	/*
+	 * Ensure the tracker is initialized when called from
+	 * constructors.
+	 */
+	lttng_ust_init_fd_tracker();
+
 	/*
 	 * If called from lttng-ust, we directly call close without
 	 * validating whether the FD is part of the tracked set.
@@ -208,6 +232,12 @@ int lttng_ust_safe_fclose_stream(FILE *stream, int (*fclose_cb)(FILE *stream))
 
 	lttng_ust_fixup_fd_tracker_tls();
 
+	/*
+	 * Ensure the tracker is initialized when called from
+	 * constructors.
+	 */
+	lttng_ust_init_fd_tracker();
+
 	/*
 	 * If called from lttng-ust, we directly call fclose without
 	 * validating whether the FD is part of the tracked set.
@@ -257,6 +287,12 @@ int lttng_ust_safe_closefrom_fd(int lowfd, int (*close_cb)(int fd))
 
 	lttng_ust_fixup_fd_tracker_tls();
 
+	/*
+	 * Ensure the tracker is initialized when called from
+	 * constructors.
+	 */
+	lttng_ust_init_fd_tracker();
+
 	if (lowfd < 0) {
 		/*
 		 * NetBSD return EBADF if fd is invalid.