linux: Only use 64-bit syscall if required for timerfd_settime

For !__ASSUME_TIME64_SYSCALLS there is no need to issue a 64-bit syscall
if the provided timeout fits in a 32-bit one.  The 64-bit usage should
be rare since the timeout is a relative one.

Checked on i686-linux-gnu on a 4.15 kernel and on a 5.11 kernel
(with and without --enable-kernel=5.1) and on x86_64-linux-gnu.

Reviewed-by: Lukasz Majewski <lukma@denx.de>

1 files changed, 32 insertions, 2 deletions

diff --git a/sysdeps/unix/sysv/linux/tst-timerfd.c b/sysdeps/unix/sysv/linux/tst-timerfd.c
index 8828399..ac4b0c4 100644
--- a/sysdeps/unix/sysv/linux/tst-timerfd.c
+++ b/sysdeps/unix/sysv/linux/tst-timerfd.c
@@ -16,15 +16,18 @@
    License along with the GNU C Library; if not, see
    <https://www.gnu.org/licenses/>.  */
 
+#include <errno.h>
+#include <intprops.h>
 #include <time.h>
 #include <support/check.h>
+#include <support/support.h>
 #include <support/xunistd.h>
 #include <support/timespec.h>
 #include <sys/time.h>
 #include <sys/timerfd.h>
 
-static int
-do_test (void)
+static void
+timerfd_test (void)
 {
   struct itimerspec settings = { { 0, 0 }, { 2, 0 } };
   struct itimerspec val;
@@ -52,6 +55,33 @@ do_test (void)
   /* Check difference between timerfd_gettime calls.  */
   TEST_COMPARE (support_timespec_check_in_range
                 ((struct timespec) { 1, 0 }, val.it_value, 0.9, 1.0), 1);
+
+  xclose (fd);
+}
+
+static void
+timerfd_large_timeout (void)
+{
+  int fd = timerfd_create (CLOCK_REALTIME, 0);
+  TEST_VERIFY (fd != -1);
+  support_create_timer (0, 100000000, false, NULL);
+  struct itimerspec it = { { 0, 0 }, { TYPE_MAXIMUM (time_t), 0 } };
+  int r = timerfd_settime (fd, 0, &it, NULL);
+  if (r == 0)
+    {
+      uint64_t buf;
+      TEST_COMPARE (read (fd, &buf, sizeof (buf)), -1);
+      TEST_VERIFY (errno == EINTR);
+    }
+  else
+    TEST_COMPARE (errno, EOVERFLOW);
+}
+
+static int
+do_test (void)
+{
+  timerfd_test ();
+  timerfd_large_timeout ();
   return 0;
 }