[glibc/azanella/y2038] linux: Add time64 recvmmsg support

[Adhemerval Zanella <azanella@sourceware.org>]

https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=d134055a4926f7ded531fc0d78c21aaa0311b1b3

commit d134055a4926f7ded531fc0d78c21aaa0311b1b3
Author: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Date:   Mon Jul 6 16:55:46 2020 -0300

    linux: Add time64 recvmmsg support
    
    The wire-up syscall __NR_recvmmsg_time64 (for 32-bit) or
    __NR_recvmmsg (for 64-bit) is used as default.  The 32-bit fallback
    is used iff __ASSUME_TIME64_SYSCALLS is not defined, which assumes the
    kernel ABI provides either __NR_socketcall or __NR_recvmmsg
    (32-bit time_t).
    
    It does not handle the timestamps on ancillary data (SCM_TIMESTAMPING
    records).
    
    Checked on x86_64-linux-gnu and i686-linux-gnu.

Diff:
---
 include/sys/socket.h               |  8 +++++
 sysdeps/unix/sysv/linux/recvmmsg.c | 63 +++++++++++++++++++++++++++++++-------
 2 files changed, 60 insertions(+), 11 deletions(-)

diff --git a/include/sys/socket.h b/include/sys/socket.h
index 26db0e0d77..0e39dd2a3a 100644
--- a/include/sys/socket.h
+++ b/include/sys/socket.h
@@ -104,6 +104,14 @@ extern ssize_t __libc_recvmsg (int __fd, struct msghdr *__message,
 			       int __flags);
 extern ssize_t __recvmsg (int __fd, struct msghdr *__message,
 			  int __flags) attribute_hidden;
+#if __TIMESIZE == 64
+# define __recvmmsg64 __recvmmsg
+#else
+extern int __recvmmsg64 (int __fd, struct mmsghdr *vmessages,
+			 unsigned int vlen, int flags,
+			 struct __timespec64 *timeout);
+libc_hidden_proto (__recvmmsg64)
+#endif
 
 /* Set socket FD's option OPTNAME at protocol level LEVEL
    to *OPTVAL (which is OPTLEN bytes long).
diff --git a/sysdeps/unix/sysv/linux/recvmmsg.c b/sysdeps/unix/sysv/linux/recvmmsg.c
index 42c80c59c3..a29c91fb76 100644
--- a/sysdeps/unix/sysv/linux/recvmmsg.c
+++ b/sysdeps/unix/sysv/linux/recvmmsg.c
@@ -16,21 +16,62 @@
    License along with the GNU C Library; if not, see
    <https://www.gnu.org/licenses/>.  */
 
-#include <errno.h>
 #include <sys/socket.h>
-
-#include <sysdep-cancel.h>
-#include <sys/syscall.h>
+#include <sysdep.h>
 #include <socketcall.h>
-#include <kernel-features.h>
 
 int
-recvmmsg (int fd, struct mmsghdr *vmessages, unsigned int vlen, int flags,
-	  struct timespec *tmo)
+__recvmmsg64 (int fd, struct mmsghdr *vmessages, unsigned int vlen, int flags,
+	      struct __timespec64 *timeout)
 {
-#ifdef __ASSUME_RECVMMSG_SYSCALL
-  return SYSCALL_CANCEL (recvmmsg, fd, vmessages, vlen, flags, tmo);
-#else
-  return SOCKETCALL_CANCEL (recvmmsg, fd, vmessages, vlen, flags, tmo);
+#ifndef __NR_recvmmsg_time64
+# define __NR_recvmmsg_time64 __NR_recvmmsg
 #endif
+  int r = SYSCALL_CANCEL (recvmmsg_time64, fd, vmessages, vlen, flags,
+			  timeout);
+#ifndef __ASSUME_TIME64_SYSCALLS
+  if (r >= 0 || errno != ENOSYS)
+    return r;
+
+  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;
+    }
+# ifdef __ASSUME_RECVMMSG_SYSCALL
+  r = SYSCALL_CANCEL (recvmmsg, fd, vmessages, vlen, flags, pts32);
+# else
+  r = SOCKETCALL_CANCEL (recvmmsg, fd, vmessages, vlen, flags, pts32);
+# endif
+  if (r >= 0 && timeout != NULL)
+    *timeout = valid_timespec_to_timespec64 (ts32);
+#endif /* __ASSUME_TIME64_SYSCALLS  */
+  return r;
 }
+#if __TIMESIZE != 64
+libc_hidden_def (__recvmmsg64)
+
+int
+__recvmmsg (int fd, struct mmsghdr *vmessages, unsigned int vlen, int flags,
+	    struct timespec *timeout)
+{
+  struct __timespec64 ts64, *pts64 = NULL;
+  if (timeout != NULL)
+    {
+      ts64 = valid_timespec_to_timespec64 (*timeout);
+      pts64 = &ts64;
+    }
+  int r = __recvmmsg64 (fd, vmessages, vlen, flags, pts64);
+  if (r >= 0)
+    /* The remanining timeout will be always less the input TIMEOUT.  */
+    *timeout = valid_timespec64_to_timespec (ts64);
+  return r;
+}
+#endif
+weak_alias (__recvmmsg, recvmmsg)