Add close_range wrapper to liblttng-ust-fd.so

[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 9909c0606a45044ab33f37ed09603d87d60dcf3c..a2227e62115cb137369a44cb3d12eb33bbcad3ab 100644 (file)
--- a/liblttng-ust-comm/lttng-ust-fd-tracker.c
+++ b/liblttng-ust-comm/lttng-ust-fd-tracker.c
@@ -479,3 +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;
+}