ust-fd: Add close_range declaration

[lttng-ust.git] / liblttng-ust-comm / lttng-ust-fd-tracker.c

diff --git a/liblttng-ust-comm/lttng-ust-fd-tracker.c b/liblttng-ust-comm/lttng-ust-fd-tracker.c
index 9659f349e54ac85a3afad50b2cfc2055abcfacfc..a2227e62115cb137369a44cb3d12eb33bbcad3ab 100644 (file)
--- a/liblttng-ust-comm/lttng-ust-fd-tracker.c
+++ b/liblttng-ust-comm/lttng-ust-fd-tracker.c
@@ -42,6 +42,7 @@
 #include <helper.h>
 #include <lttng/ust-error.h>
 #include <usterr-signal-safe.h>
+#include <lttng/ust-cancelstate.h>
 
 #include "../liblttng-ust/compat.h"
 
@@ -69,12 +70,6 @@
  */
 static pthread_mutex_t ust_safe_guard_fd_mutex = PTHREAD_MUTEX_INITIALIZER;
 
-/*
- * Cancel state when grabbing the ust_safe_guard_fd_mutex. Saved when
- * locking, restored on unlock. Protected by ust_safe_guard_fd_mutex.
- */
-static int ust_safe_guard_saved_cancelstate;
-
 /*
  * Track whether we are within lttng-ust or application, for close
  * system call override by LD_PRELOAD library. This also tracks whether
@@ -139,11 +134,10 @@ void lttng_ust_init_fd_tracker(void)
 void lttng_ust_lock_fd_tracker(void)
 {
        sigset_t sig_all_blocked, orig_mask;
-       int ret, oldstate;
+       int ret;
 
-       ret = pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &oldstate);
-       if (ret) {
-               ERR("pthread_setcancelstate: %s", strerror(ret));
+       if (lttng_ust_cancelstate_disable_push()) {
+               ERR("lttng_ust_cancelstate_disable_push");
        }
        sigfillset(&sig_all_blocked);
        ret = pthread_sigmask(SIG_SETMASK, &sig_all_blocked, &orig_mask);
@@ -157,7 +151,6 @@ void lttng_ust_lock_fd_tracker(void)
                 */
                cmm_barrier();
                pthread_mutex_lock(&ust_safe_guard_fd_mutex);
-               ust_safe_guard_saved_cancelstate = oldstate;
        }
        ret = pthread_sigmask(SIG_SETMASK, &orig_mask, NULL);
        if (ret) {
@@ -168,8 +161,7 @@ void lttng_ust_lock_fd_tracker(void)
 void lttng_ust_unlock_fd_tracker(void)
 {
        sigset_t sig_all_blocked, orig_mask;
-       int ret, newstate, oldstate;
-       bool restore_cancel = false;
+       int ret;
 
        sigfillset(&sig_all_blocked);
        ret = pthread_sigmask(SIG_SETMASK, &sig_all_blocked, &orig_mask);
@@ -182,19 +174,14 @@ void lttng_ust_unlock_fd_tracker(void)
         */
        cmm_barrier();
        if (!--URCU_TLS(ust_fd_mutex_nest)) {
-               newstate = ust_safe_guard_saved_cancelstate;
-               restore_cancel = true;
                pthread_mutex_unlock(&ust_safe_guard_fd_mutex);
        }
        ret = pthread_sigmask(SIG_SETMASK, &orig_mask, NULL);
        if (ret) {
                ERR("pthread_sigmask: %s", strerror(ret));
        }
-       if (restore_cancel) {
-               ret = pthread_setcancelstate(newstate, &oldstate);
-               if (ret) {
-                       ERR("pthread_setcancelstate: %s", strerror(ret));
-               }
+       if (lttng_ust_cancelstate_disable_pop()) {
+               ERR("lttng_ust_cancelstate_disable_pop");
        }
 }
 
@@ -492,3 +479,62 @@ int lttng_ust_safe_closefrom_fd(int lowfd, int (*close_cb)(int fd))
 end:
        return ret;
 }
+
+/*
+ * Implement helper for close_range() override.
+ */
+int lttng_ust_safe_close_range_fd(unsigned int first, unsigned int last, int flags,
+               int (*close_range_cb)(unsigned int first, unsigned int last, int flags))
+{
+       int ret = 0, i;
+
+       lttng_ust_fixup_fd_tracker_tls();
+
+       /*
+        * Ensure the tracker is initialized when called from
+        * constructors.
+        */
+       lttng_ust_init_fd_tracker();
+
+       if (first > last || last > INT_MAX) {
+               ret = -1;
+               errno = EINVAL;
+               goto end;
+       }
+       /*
+        * If called from lttng-ust, we directly call close_range
+        * without validating whether the FD is part of the tracked set.
+        */
+       if (URCU_TLS(ust_fd_mutex_nest)) {
+               if (close_range_cb(first, last, flags) < 0) {
+                       ret = -1;
+                       goto end;
+               }
+       } else {
+               int last_check = last;
+
+               if (last > lttng_ust_max_fd)
+                       last_check = lttng_ust_max_fd;
+               lttng_ust_lock_fd_tracker();
+               for (i = first; i <= last_check; i++) {
+                       if (IS_FD_VALID(i) && IS_FD_SET(i, lttng_fd_set))
+                               continue;
+                       if (close_range_cb(i, i, flags) < 0) {
+                               ret = -1;
+                               /* propagate errno from close_range_cb. */
+                               lttng_ust_unlock_fd_tracker();
+                               goto end;
+                       }
+               }
+               if (last > lttng_ust_max_fd) {
+                       if (close_range_cb(lttng_ust_max_fd + 1, last, flags) < 0) {
+                               ret = -1;
+                               lttng_ust_unlock_fd_tracker();
+                               goto end;
+                       }
+               }
+               lttng_ust_unlock_fd_tracker();
+       }
+end:
+       return ret;
+}