diff -up smartmontools-7.2/configure.ac.fixfdclose smartmontools-7.2/configure.ac
--- smartmontools-7.2/configure.ac.fixfdclose	2024-01-10 16:45:10.994784319 +0100
+++ smartmontools-7.2/configure.ac	2024-01-10 16:47:27.985999103 +0100
@@ -121,6 +121,16 @@ AM_CONDITIONAL(NEED_GETOPT_LONG, [test "
 
 AC_CHECK_FUNCS([clock_gettime ftime gettimeofday])
 
+case "$host_os" in
+  mingw*)
+    # Older MinGW-w64 (5.0.3) require -lwinpthread
+    AC_SEARCH_LIBS([clock_gettime], [winpthread])
+    ;;
+  *)
+    AC_CHECK_FUNCS([close_range])
+    ;;
+esac
+
 # Check byte ordering (defines WORDS_BIGENDIAN)
 AC_C_BIGENDIAN
 
diff -up smartmontools-7.2/smartd.cpp.fixfdclose smartmontools-7.2/smartd.cpp
--- smartmontools-7.2/smartd.cpp.fixfdclose	2024-01-10 16:45:10.996784336 +0100
+++ smartmontools-7.2/smartd.cpp	2024-01-10 16:46:33.786518090 +0100
@@ -1475,8 +1475,16 @@ static int daemon_init()
   }
 
   // close any open file descriptors
-  for (int i = getdtablesize(); --i >= 0; )
-    close(i);
+  int open_max = sysconf(_SC_OPEN_MAX);
+#ifdef HAVE_CLOSE_RANGE
+  if (close_range(0, open_max - 1, 0))
+#endif
+  {
+    // Limit number of close() calls under the assumption that there
+    // are no large gaps between open FDs
+    for (int i = 0, failed = 0; i < open_max && failed < 1024; i++)
+      failed = (!close(i) ? 0 : failed + 1);
+  }
   
   // redirect any IO attempts to /dev/null and change to root directory
   int fd = open("/dev/null", O_RDWR);