[newlib-cygwin] Cygwin: timerfd/signalfd: return EINVAL from write

[Corinna Vinschen <corinna@sourceware.org>]

https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=7f983079d4a62e3f906a97bf091908a1dad29bb6

commit 7f983079d4a62e3f906a97bf091908a1dad29bb6
Author: Corinna Vinschen <corinna@vinschen.de>
Date:   Thu Jan 17 11:51:11 2019 +0100

    Cygwin: timerfd/signalfd: return EINVAL from write
    
    Linux returns EINVAL, "fd is attached to an object which is unsuitable
    for writing".  If we don't handle write locally, write returns EBADF.
    
    Signed-off-by: Corinna Vinschen <corinna@vinschen.de>

Diff:
---
 winsup/cygwin/fhandler.h           |  2 ++
 winsup/cygwin/fhandler_signalfd.cc |  8 ++++++++
 winsup/cygwin/fhandler_timerfd.cc  | 17 +++++++++++------
 3 files changed, 21 insertions(+), 6 deletions(-)

diff --git a/winsup/cygwin/fhandler.h b/winsup/cygwin/fhandler.h
index f0c612d..497612a 100644
--- a/winsup/cygwin/fhandler.h
+++ b/winsup/cygwin/fhandler.h
@@ -2650,6 +2650,7 @@ class fhandler_signalfd : public fhandler_base
   int signalfd (const sigset_t *mask, int flags);
   int __reg2 fstat (struct stat *buf);
   void __reg3 read (void *ptr, size_t& len);
+  ssize_t __stdcall write (const void *, size_t);
 
   int poll ();
   inline sigset_t get_sigset () const { return sigset; }
@@ -2693,6 +2694,7 @@ class fhandler_timerfd : public fhandler_base
 
   int __reg2 fstat (struct stat *buf);
   void __reg3 read (void *ptr, size_t& len);
+  ssize_t __stdcall write (const void *, size_t);
   int dup (fhandler_base *child, int);
   int ioctl (unsigned int, void *);
   int close ();
diff --git a/winsup/cygwin/fhandler_signalfd.cc b/winsup/cygwin/fhandler_signalfd.cc
index d8e17a8..6c7da02 100644
--- a/winsup/cygwin/fhandler_signalfd.cc
+++ b/winsup/cygwin/fhandler_signalfd.cc
@@ -49,6 +49,7 @@ fhandler_signalfd::signalfd (const sigset_t *mask, int flags)
       nohandle (true);
       set_unique_id ();
       set_ino (get_unique_id ());
+      set_flags (O_RDWR | O_BINARY);
     }
   return 0;
 }
@@ -139,6 +140,13 @@ fhandler_signalfd::read (void *ptr, size_t& len)
   return;
 }
 
+ssize_t __stdcall
+fhandler_signalfd::write (const void *, size_t)
+{
+  set_errno (EINVAL);
+  return -1;
+}
+
 /* Called from select */
 int
 fhandler_signalfd::poll ()
diff --git a/winsup/cygwin/fhandler_timerfd.cc b/winsup/cygwin/fhandler_timerfd.cc
index 360731c..c7ff9c1 100644
--- a/winsup/cygwin/fhandler_timerfd.cc
+++ b/winsup/cygwin/fhandler_timerfd.cc
@@ -44,12 +44,10 @@ fhandler_timerfd::timerfd (clockid_t clock_id, int flags)
     set_nonblocking (true);
   if (flags & TFD_CLOEXEC)
     set_close_on_exec (true);
-  if (get_unique_id () == 0)
-    {
-      nohandle (true);
-      set_unique_id ();
-      set_ino (get_unique_id ());
-    }
+  nohandle (true);
+  set_unique_id ();
+  set_ino (get_unique_id ());
+  set_flags (O_RDWR | O_BINARY);
   return 0;
 }
 
@@ -125,6 +123,13 @@ fhandler_timerfd::read (void *ptr, size_t& len)
   return;
 }
 
+ssize_t __stdcall
+fhandler_timerfd::write (const void *, size_t)
+{
+  set_errno (EINVAL);
+  return -1;
+}
+
 HANDLE
 fhandler_timerfd::get_timerfd_handle ()
 {