hurd: clean fd and port on thread cancel

HURD_*PORT_USE link fd and port with a stack-stored structure, so on
thread cancel we need to cleanup this.

* hurd/fd-cleanup.c: New file.
* hurd/port-cleanup.c (_hurd_port_use_cleanup): New function.
* hurd/Makefile (routines): Add fd-cleanup.
* sysdeps/hurd/include/hurd.h (__USEPORT_CANCEL): New macro.
* sysdeps/hurd/include/hurd/fd.h (_hurd_fd_port_use_data): New
structure.
(_hurd_fd_port_use_cleanup): New prototype.
(HURD_DPORT_USE_CANCEL, HURD_FD_PORT_USE_CANCEL): New macros.
* sysdeps/hurd/include/hurd/port.h (_hurd_port_use_data): New structure.
(_hurd_port_use_cleanup): New prototype.
(HURD_PORT_USE_CANCEL): New macro.
* hurd/hurd/fd.h (HURD_FD_PORT_USE): Also refer to HURD_FD_PORT_USE_CANCEL.
* hurd/hurd.h (__USEPORT): Also refer to __USEPORT_CANCEL.
* hurd/hurd/port.h (HURD_PORT_USE): Also refer to HURD_PORT_USE_CANCEL.

* hurd/fd-read.c (_hurd_fd_read): Call HURD_FD_PORT_USE_CANCEL instead
of HURD_FD_PORT_USE.
* hurd/fd-write.c (_hurd_fd_write): Likewise.
* sysdeps/mach/hurd/send.c (__send): Call HURD_DPORT_USE_CANCEL instead
of HURD_DPORT_USE.
* sysdeps/mach/hurd/sendmsg.c (__libc_sendmsg): Likewise.
* sysdeps/mach/hurd/sendto.c (__sendto): Likewise.
* sysdeps/mach/hurd/recv.c (__recv): Likewise.
* sysdeps/mach/hurd/recvfrom.c (__recvfrom): Likewise.
* sysdeps/mach/hurd/recvmsg.c (__libc_recvmsg): Call __USEPORT_CANCEL
instead of __USEPORT, and HURD_DPORT_USE_CANCEL instead of
HURD_DPORT_USE.

8 files changed, 52 insertions, 4 deletions

diff --git a/hurd/Makefile b/hurd/Makefile
index 1ace90d..861bbf7 100644
--- a/hurd/Makefile
+++ b/hurd/Makefile
@@ -56,7 +56,8 @@ routines = hurdstartup hurdinit \
 	   ports-get ports-set hurdports hurdmsg \
 	   errno-loc \
 	   hurdlock \
-	   $(sig) $(dtable) $(inlines) port-cleanup report-wait xattr
+	   $(sig) $(dtable) $(inlines) \
+	   fd-cleanup port-cleanup report-wait xattr
 sig	= hurdsig hurdfault siginfo hurd-raise preempt-sig \
 	  trampoline longjmp-ts catch-exc exc2signal hurdkill sigunwind \
 	  thread-self thread-cancel intr-msg catch-signal
diff --git a/hurd/fd-cleanup.c b/hurd/fd-cleanup.c
new file mode 100644
index 0000000..83bde6f
--- /dev/null
+++ b/hurd/fd-cleanup.c
@@ -0,0 +1,33 @@
+/* Cleanup function for `struct hurd_fd' users.
+   Copyright (C) 1995-2020 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 <mach.h>
+#include <hurd/fd.h>
+
+/* We were cancelled while using an fd, and called from the cleanup unwinding.
+ */
+
+void
+_hurd_fd_port_use_cleanup (void *arg)
+{
+  struct _hurd_fd_port_use_data *data = arg;
+
+  _hurd_port_free (&data->d->port, &data->ulink, data->port);
+  if (data->ctty != MACH_PORT_NULL)
+    _hurd_port_free (&data->d->ctty, &data->ctty_ulink, data->ctty);
+}
diff --git a/hurd/fd-read.c b/hurd/fd-read.c
index 11c435f..1a8f203 100644
--- a/hurd/fd-read.c
+++ b/hurd/fd-read.c
@@ -35,7 +35,7 @@ _hurd_fd_read (struct hurd_fd *fd, void *buf, size_t *nbytes, loff_t offset)
 
   data = buf;
   nread = *nbytes;
-  if (err = HURD_FD_PORT_USE (fd, _hurd_ctty_input (port, ctty, readfd)))
+  if (err = HURD_FD_PORT_USE_CANCEL (fd, _hurd_ctty_input (port, ctty, readfd)))
     return err;
 
   if (data != buf)
diff --git a/hurd/fd-write.c b/hurd/fd-write.c
index f63bae5..2463cea 100644
--- a/hurd/fd-write.c
+++ b/hurd/fd-write.c
@@ -33,7 +33,7 @@ _hurd_fd_write (struct hurd_fd *fd,
       return __io_write (port, buf, *nbytes, offset, &wrote);
     }
 
-  err = HURD_FD_PORT_USE (fd, _hurd_ctty_output (port, ctty, writefd));
+  err = HURD_FD_PORT_USE_CANCEL (fd, _hurd_ctty_output (port, ctty, writefd));
 
   if (! err)
     *nbytes = wrote;
diff --git a/hurd/hurd.h b/hurd/hurd.h
index cd7a149..8f1fdf4 100644
--- a/hurd/hurd.h
+++ b/hurd/hurd.h
@@ -92,6 +92,7 @@ extern sigset_t _hurdsig_traced;
 
 /* Shorthand macro for internal library code referencing _hurd_ports (see
    <hurd/port.h>).  */
+/* Also see __USEPORT_CANCEL.  */
 
 #define	__USEPORT(which, expr) \
   HURD_PORT_USE (&_hurd_ports[INIT_PORT_##which], (expr))
diff --git a/hurd/hurd/fd.h b/hurd/hurd/fd.h
index e18c3ce..d27be21 100644
--- a/hurd/hurd/fd.h
+++ b/hurd/hurd/fd.h
@@ -115,6 +115,7 @@ _hurd_fd_get (int fd)
   HURD_FD_USE ((fd), HURD_FD_PORT_USE (descriptor, (expr)))
 
 /* Likewise, but FD is a pointer to the file descriptor structure.  */
+/* Also see HURD_FD_PORT_USE_CANCEL.  */
 
 #define	HURD_FD_PORT_USE(fd, expr)					      \
   ({ error_t __result;							      \
diff --git a/hurd/hurd/port.h b/hurd/hurd/port.h
index 33e696a..f91b1d5 100644
--- a/hurd/hurd/port.h
+++ b/hurd/hurd/port.h
@@ -42,6 +42,7 @@ struct hurd_port
 
 
 /* Evaluate EXPR with the variable `port' bound to the port in PORTCELL.  */
+/* Also see HURD_PORT_USE_CANCEL.  */
 
 #define	HURD_PORT_USE(portcell, expr)					      \
   ({ struct hurd_port *const __p = (portcell);				      \
diff --git a/hurd/port-cleanup.c b/hurd/port-cleanup.c
index 0bb8267..95b019c 100644
--- a/hurd/port-cleanup.c
+++ b/hurd/port-cleanup.c
@@ -1,4 +1,4 @@
-/* Cleanup function for `struct hurd_port' users who longjmp.
+/* Cleanup function for `struct hurd_port' users.
    Copyright (C) 1995-2020 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
 
@@ -28,3 +28,14 @@ _hurd_port_cleanup (void *cleanup_data, jmp_buf env, int val)
 {
   __mach_port_deallocate (__mach_task_self (), (mach_port_t) cleanup_data);
 }
+
+/* We were cancelled while using a port, and called from the cleanup unwinding.
+ */
+
+void
+_hurd_port_use_cleanup (void *arg)
+{
+  struct _hurd_port_use_data *data = arg;
+
+  _hurd_port_free (data->p, &data->link, data->port);
+}