hurd: Fix __writev_nocancel_nostatus

* sysdeps/mach/hurd/Makefile [subdir=misc] (sysdep_routines): Add
writev_nocancel writev_nocancel_nostatus.
* sysdeps/mach/hurd/not-cancel.h (__writev_nocancel_nostatus): Replace
macro with function declaration (with hidden prototype in libc).
(__writev_nocancel): New function declaration (with hidden prototype in libc).
* sysdeps/mach/hurd/writev_nocancel_nostatus.c: New file.
* sysdeps/posix/writev_nocancel.c: New file, includes writev.c to make a
nocancel variant that calls __write_nocancel.
* sysdeps/posix/writev.c (writev): Do not define alias if __writev is
renamed.

sysdeps/mach/hurd/Makefile

@@ -200,6 +200,10 @@ sysdep_routines += f_setlk close_nocancel_nostatus read_nocancel \
 		   pread64_nocancel write_nocancel pwrite64_nocancel
 endif
 
+ifeq (misc, $(subdir))
+sysdep_routines += writev_nocancel writev_nocancel_nostatus
+endif
+
 ifeq ($(subdir),sunrpc)
 sysdep_headers += nfs/nfs.h
 endif

sysdeps/mach/hurd/not-cancel.h

@@ -54,8 +54,12 @@ __typeof (__write) __write_nocancel;
 /* Non cancellable pwrite syscall (LFS version).  */
 __typeof (__pwrite64) __pwrite64_nocancel;
 
-#define __writev_nocancel_nostatus(fd, iov, n) \
+/* Non cancellable writev syscall.  */
-  (void) __writev (fd, iov, n)
+__typeof (__writev) __writev_nocancel;
+
+/* Non cancellable writev syscall with no status.  */
+void __writev_nocancel_nostatus (int fd, const struct iovec *vector, int count);
+
 # define __waitpid_nocancel(pid, stat_loc, options) \
   __waitpid (pid, stat_loc, options)
 #define __fcntl64_nocancel(fd, cmd, ...) \
@@ -66,6 +70,8 @@ hidden_proto (__read_nocancel)
 hidden_proto (__pread64_nocancel)
 hidden_proto (__write_nocancel)
 hidden_proto (__pwrite64_nocancel)
+hidden_proto (__writev_nocancel)
+hidden_proto (__writev_nocancel_nostatus)
 hidden_proto (__close_nocancel_nostatus)
 #endif
 

sysdeps/mach/hurd/writev_nocancel_nostatus.c

@@ -0,0 +1,28 @@
+/* Copyright (C) 1991-2020 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#include <errno.h>
+#include <not-cancel.h>
+
+void
+__writev_nocancel_nostatus (int fd, const struct iovec *vector, int count)
+{
+  int save = errno;
+  __writev_nocancel (fd, vector, count);
+  __set_errno (save);
+}
+libc_hidden_weak (__writev_nocancel_nostatus)

sysdeps/posix/writev.c

@@ -89,4 +89,6 @@ __writev (int fd, const struct iovec *vector, int count)
   return bytes_written;
 }
 libc_hidden_def (__writev)
+#ifndef __writev
 weak_alias (__writev, writev)
+#endif

sysdeps/posix/writev_nocancel.c

@@ -0,0 +1,4 @@
+#include <not-cancel.h>
+#define __writev __writev_nocancel
+#define __write __write_nocancel
+#include <sysdeps/posix/writev.c>