summary |
shortlog |
log |
commit | commitdiff |
tree
raw |
patch |
inline | side by side (from parent 1:
96a6162)
Split the thread_fd_tracking state from the ust_fd_mutex_nest used to
track whether a signal handler is nested over a fd tracker lock.
lttng-ust listener threads need to invoke
lttng_ust_fd_tracker_register_thread() so the fd tracker can
distinguish them from application threads.
Otherwise, using ust_fd_mutex_nest to try to distinguish between
ust and application threads makes it possible for signal handlers
to appear as if they are ust listener threads, and thus attempt to
close UST file descriptors.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Fixes: #1199
void lttng_ust_delete_fd_from_tracker(int fd);
void lttng_ust_lock_fd_tracker(void);
void lttng_ust_unlock_fd_tracker(void);
void lttng_ust_delete_fd_from_tracker(int fd);
void lttng_ust_lock_fd_tracker(void);
void lttng_ust_unlock_fd_tracker(void);
+void lttng_ust_fd_tracker_register_thread(void);
int lttng_ust_safe_close_fd(int fd, int (*close_cb)(int));
int lttng_ust_safe_fclose_stream(FILE *stream, int (*fclose_cb)(FILE *stream));
int lttng_ust_safe_close_fd(int fd, int (*close_cb)(int));
int lttng_ust_safe_fclose_stream(FILE *stream, int (*fclose_cb)(FILE *stream));
/*
* Track whether we are within lttng-ust or application, for close
/*
* Track whether we are within lttng-ust or application, for close
- * system call override by LD_PRELOAD library. This also tracks whether
- * we are invoking close() from a signal handler nested on an
- * application thread.
+ * system call override by LD_PRELOAD library. Threads registered
+ * as being lttng-ust listener threads need to perform fd tracker
+ * locking explicitly around their use of file descriptor manipulation
+ * functions.
+ */
+static DEFINE_URCU_TLS(int, thread_fd_tracking);
+
+/*
+ * Track whether we are invoking close() from a signal handler nested on
+ * an application thread.
*/
static DEFINE_URCU_TLS(int, ust_fd_mutex_nest);
*/
static DEFINE_URCU_TLS(int, ust_fd_mutex_nest);
/* fd_set used to book keep fd being used by lttng-ust. */
static fd_set *lttng_fd_set;
static int lttng_ust_max_fd;
/* fd_set used to book keep fd being used by lttng-ust. */
static fd_set *lttng_fd_set;
static int lttng_ust_max_fd;
*/
void lttng_ust_fixup_fd_tracker_tls(void)
{
*/
void lttng_ust_fixup_fd_tracker_tls(void)
{
+ asm volatile ("" : : "m" (URCU_TLS(thread_fd_tracking)));
asm volatile ("" : : "m" (URCU_TLS(ust_fd_mutex_nest)));
}
asm volatile ("" : : "m" (URCU_TLS(ust_fd_mutex_nest)));
}
* If called from lttng-ust, we directly call close without
* validating whether the FD is part of the tracked set.
*/
* If called from lttng-ust, we directly call close without
* validating whether the FD is part of the tracked set.
*/
- if (URCU_TLS(ust_fd_mutex_nest))
+ if (URCU_TLS(thread_fd_tracking))
return close_cb(fd);
lttng_ust_lock_fd_tracker();
return close_cb(fd);
lttng_ust_lock_fd_tracker();
* If called from lttng-ust, we directly call fclose without
* validating whether the FD is part of the tracked set.
*/
* If called from lttng-ust, we directly call fclose without
* validating whether the FD is part of the tracked set.
*/
- if (URCU_TLS(ust_fd_mutex_nest))
+ if (URCU_TLS(thread_fd_tracking))
return fclose_cb(stream);
fd = fileno(stream);
return fclose_cb(stream);
fd = fileno(stream);
* If called from lttng-ust, we directly call close without
* validating whether the FD is part of the tracked set.
*/
* If called from lttng-ust, we directly call close without
* validating whether the FD is part of the tracked set.
*/
- if (URCU_TLS(ust_fd_mutex_nest)) {
+ if (URCU_TLS(thread_fd_tracking)) {
for (i = lowfd; i < lttng_ust_max_fd; i++) {
if (close_cb(i) < 0) {
switch (errno) {
for (i = lowfd; i < lttng_ust_max_fd; i++) {
if (close_cb(i) < 0) {
switch (errno) {
+
+void lttng_ust_fd_tracker_register_thread(void)
+{
+ URCU_TLS(thread_fd_tracking) = 1;
+}
long timeout;
lttng_ust_fixup_tls();
long timeout;
lttng_ust_fixup_tls();
+ lttng_ust_fd_tracker_register_thread();
/*
* If available, add '-ust' to the end of this thread's
* process name
/*
* If available, add '-ust' to the end of this thread's
* process name