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

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>

diff --git a/sysdeps/unix/sysv/linux/semtimedop.c b/sysdeps/unix/sysv/linux/semtimedop.c
index b732b6db48a9d8a8a94ff8921c6fcd06cc68a930..d4fea4e55a50011c1f25cfbaf684253bdb28113d 100644 (file)
--- a/sysdeps/unix/sysv/linux/semtimedop.c
+++ b/sysdeps/unix/sysv/linux/semtimedop.c
@@ -21,44 +21,51 @@
 #include <sysdep.h>
 #include <errno.h>
 
+static int
+semtimedop_syscall (int semid, struct sembuf *sops, size_t nsops,
+                   const struct __timespec64 *timeout)
+{
+#ifdef __NR_semtimedop_time64
+  return INLINE_SYSCALL_CALL (semtimedop_time64, semid, sops, nsops, timeout);
+#elif defined __ASSUME_DIRECT_SYSVIPC_SYSCALLS && defined __NR_semtimedop
+  return INLINE_SYSCALL_CALL (semtimedop, semid, sops, nsops, timeout);
+#else
+  return INLINE_SYSCALL_CALL (ipc, IPCOP_semtimedop, semid,
+                             SEMTIMEDOP_IPC_ARGS (nsops, sops, timeout));
+#endif
+}
+
 /* Perform user-defined atomical operation of array of semaphores.  */
 int
 __semtimedop64 (int semid, struct sembuf *sops, size_t nsops,
                const struct __timespec64 *timeout)
 {
-  int r;
-#if defined __NR_semtimedop_time64
-  r = INLINE_SYSCALL_CALL (semtimedop_time64, semid, sops, nsops, timeout);
-#elif defined __ASSUME_DIRECT_SYSVIPC_SYSCALLS && defined __NR_semtimedop
-  r = INLINE_SYSCALL_CALL (semtimedop, semid, sops, nsops, timeout);
+#ifdef __ASSUME_TIME64_SYSCALLS
+  return semtimedop_syscall (semid, sops, nsops, timeout);
 #else
-  r = INLINE_SYSCALL_CALL (ipc, IPCOP_semtimedop, semid,
-                          SEMTIMEDOP_IPC_ARGS (nsops, sops, timeout));
-#endif
-
-#ifndef __ASSUME_TIME64_SYSCALLS
-  if (r == 0 || errno != ENOSYS)
-    return r;
+  bool need_time64 = timeout != NULL && !in_time_t_range (timeout->tv_sec);
+  if (need_time64)
+    {
+      int r = semtimedop_syscall (semid, sops, nsops, timeout);
+      if (r == 0 || errno != ENOSYS)
+       return r;
+      __set_errno (EOVERFLOW);
+      return -1;
+    }
 
   struct timespec ts32, *pts32 = NULL;
   if (timeout != NULL)
     {
-      if (! in_time_t_range (timeout->tv_sec))
-       {
-         __set_errno (EINVAL);
-         return -1;
-       }
       ts32 = valid_timespec64_to_timespec (*timeout);
       pts32 = &ts32;
     }
-# if defined __ASSUME_DIRECT_SYSVIPC_SYSCALLS
-  r = INLINE_SYSCALL_CALL (semtimedop, semid, sops, nsops, pts32);
+# ifdef __ASSUME_DIRECT_SYSVIPC_SYSCALLS
+  return INLINE_SYSCALL_CALL (semtimedop, semid, sops, nsops, pts32);
 # else
-  r = INLINE_SYSCALL_CALL (ipc, IPCOP_semtimedop, semid,
-                          SEMTIMEDOP_IPC_ARGS (nsops, sops, pts32));
+  return INLINE_SYSCALL_CALL (ipc, IPCOP_semtimedop, semid,
+                             SEMTIMEDOP_IPC_ARGS (nsops, sops, pts32));
 # endif
-#endif /* __ASSUME_TIME64_SYSCALLS  */
-  return r;
+#endif
 }
 #if __TIMESIZE != 64
 libc_hidden_def (__semtimedop64)

diff --git a/sysvipc/Makefile b/sysvipc/Makefile
index 86911803b5627ec129f2c2f39fca7261be6d79b8..d2acb6a70b466932c891784a707f439744917e28 100644 (file)
--- a/sysvipc/Makefile
+++ b/sysvipc/Makefile
@@ -38,3 +38,12 @@ include ../Rules
 
 CFLAGS-msgrcv.c += -fexceptions -fasynchronous-unwind-tables
 CFLAGS-msgsnd.c += -fexceptions -fasynchronous-unwind-tables
+
+ifeq (yes,$(build-shared))
+librt = $(common-objpfx)rt/librt.so
+else
+librt = $(common-objpfx)rt/librt.a
+endif
+
+$(objpfx)test-sysvsem: $(librt)
+$(objpfx)test-sysvsem-time64: $(librt)

diff --git a/sysvipc/test-sysvsem.c b/sysvipc/test-sysvsem.c
index 092418205d9aa9cd7c764b20122bae72774c1b58..d9034c3daeac23c1b047a5d862064825a3185194 100644 (file)
--- a/sysvipc/test-sysvsem.c
+++ b/sysvipc/test-sysvsem.c
@@ -16,6 +16,7 @@
    License along with the GNU C Library; if not, see
    <https://www.gnu.org/licenses/>.  */
 
+#include <intprops.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <errno.h>
@@ -30,6 +31,8 @@
 #include <support/support.h>
 #include <support/check.h>
 #include <support/temp_file.h>
+#include <support/xtime.h>
+#include <support/xsignal.h>
 
 /* These are for the temporary file we generate.  */
 static char *name;
@@ -112,11 +115,20 @@ do_test (void)
 #ifdef _GNU_SOURCE
   /* Set a time for half a second.  The semaphore operation should timeout
      with EAGAIN.  */
-  struct timespec ts = { 0 /* sec */, 500000000 /* nsec */ };
-  if (semtimedop (semid, &sb2, 1, &ts) != -1
-      || (errno != EAGAIN && errno != ENOSYS))
-    FAIL_EXIT1 ("semtimedop succeed or returned errno != {EAGAIN,ENOSYS} "
-               "(errno=%i)", errno);
+  {
+    struct timespec ts = { 0 /* sec */, 500000000 /* nsec */ };
+    if (semtimedop (semid, &sb2, 1, &ts) != -1
+        || (errno != EAGAIN && errno != ENOSYS))
+      FAIL_EXIT1 ("semtimedop succeed or returned errno != {EAGAIN,ENOSYS} "
+                 "(errno=%i)", errno);
+  }
+
+  {
+    support_create_timer (0, 100000000, false, NULL);
+    struct timespec ts = { TYPE_MAXIMUM (time_t), 0 };
+    TEST_COMPARE (semtimedop (semid, &sb2, 1, &ts), -1);
+    TEST_VERIFY (errno == EINTR || errno == EOVERFLOW);
+  }
 #endif
 
   /* Finally free up the semnaphore resource.  */