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authorAdhemerval Zanella <adhemerval.zanella@linaro.org>2021-06-15 23:05:21 -0300
committerAdhemerval Zanella <adhemerval.zanella@linaro.org>2021-06-22 12:09:52 -0300
commite9e912d3349d8caf3c40bc09370509724c72ac2f (patch)
tree799aca4681edcb8bdce77c116b252b324340d4f5 /sysdeps/unix/sysv
parent2c0982eb93c37af30583a117589ceb0ab3402c11 (diff)
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linux: Only use 64-bit syscall if required for mq_timedreceive
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/unix/sysv')
-rw-r--r--sysdeps/unix/sysv/linux/mq_timedreceive.c35
1 files changed, 19 insertions, 16 deletions
diff --git a/sysdeps/unix/sysv/linux/mq_timedreceive.c b/sysdeps/unix/sysv/linux/mq_timedreceive.c
index eb948ccc18..1a7b7a9c11 100644
--- a/sysdeps/unix/sysv/linux/mq_timedreceive.c
+++ b/sysdeps/unix/sysv/linux/mq_timedreceive.c
@@ -29,30 +29,33 @@ __mq_timedreceive_time64 (mqd_t mqdes, char *__restrict msg_ptr, size_t msg_len,
 #ifndef __NR_mq_timedreceive_time64
 # define __NR_mq_timedreceive_time64 __NR_mq_timedreceive
 #endif
-  int ret = SYSCALL_CANCEL (mq_timedreceive_time64, mqdes, msg_ptr, msg_len,
-                            msg_prio, abs_timeout);
 
-#ifndef __ASSUME_TIME64_SYSCALLS
-  if (ret == 0 || errno != ENOSYS)
-    return ret;
+#ifdef __ASSUME_TIME64_SYSCALLS
+  return SYSCALL_CANCEL (mq_timedreceive_time64, mqdes, msg_ptr, msg_len,
+			 msg_prio, abs_timeout);
+#else
+  bool need_time64 = abs_timeout != NULL
+		     && !in_time_t_range (abs_timeout->tv_sec);
+  if (need_time64)
+    {
+      int r = SYSCALL_CANCEL (mq_timedreceive_time64, mqdes, msg_ptr, msg_len,
+			      msg_prio, abs_timeout);
+      if (r == 0 || errno != ENOSYS)
+	return r;
+      __set_errno (EOVERFLOW);
+      return -1;
+    }
 
-  struct timespec ts32;
+  struct timespec ts32, *pts32 = NULL;
   if (abs_timeout != NULL)
     {
-      if (! in_time_t_range (abs_timeout->tv_sec))
-        {
-          __set_errno (EOVERFLOW);
-          return -1;
-        }
-
       ts32 = valid_timespec64_to_timespec (*abs_timeout);
+      pts32 = &ts32;
     }
 
-  ret = SYSCALL_CANCEL (mq_timedreceive, mqdes, msg_ptr, msg_len, msg_prio,
-			abs_timeout != NULL ? &ts32 : NULL);
+  return SYSCALL_CANCEL (mq_timedreceive, mqdes, msg_ptr, msg_len, msg_prio,
+			 pts32);
 #endif
-
-  return ret;
 }
 
 #if __TIMESIZE != 64