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authorAdhemerval Zanella <adhemerval.zanella@linaro.org>2021-06-15 22:43:51 -0300
committerAdhemerval Zanella <adhemerval.zanella@linaro.org>2021-06-22 12:09:52 -0300
commiteef7913c2f5512a954e658a5908a47dbc0ec8c2e (patch)
treeefd27199fcfd2dbe5b2ee13d2fc53fac130b5d51 /sysdeps
parent4b6551902e5c701e5f3156928d88aadeb6487dc1 (diff)
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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>
Diffstat (limited to 'sysdeps')
-rw-r--r--sysdeps/unix/sysv/linux/semtimedop.c53
1 files changed, 30 insertions, 23 deletions
diff --git a/sysdeps/unix/sysv/linux/semtimedop.c b/sysdeps/unix/sysv/linux/semtimedop.c
index b732b6db48..d4fea4e55a 100644
--- 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)