From 67a78072e2891b8b16a7bfb20675844a5854cff1 Mon Sep 17 00:00:00 2001
From: Samuel Thibault <samuel.thibault@ens-lyon.org>
Date: Sun, 28 Jun 2020 00:15:56 +0000
Subject: 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.
---
 sysdeps/hurd/include/hurd.h      |  5 +++++
 sysdeps/hurd/include/hurd/fd.h   | 41 ++++++++++++++++++++++++++++++++++++++++
 sysdeps/hurd/include/hurd/port.h | 24 +++++++++++++++++++++++
 3 files changed, 70 insertions(+)

(limited to 'sysdeps/hurd')

diff --git a/sysdeps/hurd/include/hurd.h b/sysdeps/hurd/include/hurd.h
index d29f580d5b..dc877173b5 100644
--- a/sysdeps/hurd/include/hurd.h
+++ b/sysdeps/hurd/include/hurd.h
@@ -1,5 +1,10 @@
 #ifndef	_HURD_H
 #include_next <hurd.h>
+
+/* Like __USEPORT, but cleans fd on cancel.  */
+#define	__USEPORT_CANCEL(which, expr) \
+  HURD_PORT_USE_CANCEL (&_hurd_ports[INIT_PORT_##which], (expr))
+
 #ifndef _ISOMAC
 libc_hidden_proto (_hurd_exec_paths)
 libc_hidden_proto (_hurd_init)
diff --git a/sysdeps/hurd/include/hurd/fd.h b/sysdeps/hurd/include/hurd/fd.h
index 1f3ac380a0..3a6cdc7f36 100644
--- a/sysdeps/hurd/include/hurd/fd.h
+++ b/sysdeps/hurd/include/hurd/fd.h
@@ -1,6 +1,47 @@
 #ifndef	_HURD_FD_H
 #include_next <hurd/fd.h>
+
 #ifndef _ISOMAC
+#include <libc-lock.h>
+
+struct _hurd_fd_port_use_data
+  {
+     struct hurd_fd *d;
+     struct hurd_userlink ulink, ctty_ulink;
+     io_t port, ctty;
+  };
+
+extern void _hurd_fd_port_use_cleanup (void *arg);
+
+/* Like HURD_DPORT_USE, but cleans fd on cancel.  */
+#define HURD_DPORT_USE_CANCEL(fd, expr) \
+  HURD_FD_USE ((fd), HURD_FD_PORT_USE_CANCEL (descriptor, (expr)))
+
+/* Like HURD_FD_PORT_USE, but cleans fd on cancel.  */
+#define	HURD_FD_PORT_USE_CANCEL(fd, expr)				      \
+  ({ error_t __result;							      \
+     void *__crit = _hurd_critical_section_lock ();			      \
+     struct _hurd_fd_port_use_data __d;					      \
+     io_t port, ctty;							      \
+     __d.d = (fd);							      \
+     __spin_lock (&__d.d->port.lock);					      \
+     if (__d.d->port.port == MACH_PORT_NULL)				      \
+       {								      \
+	 __spin_unlock (&__d.d->port.lock);				      \
+	 _hurd_critical_section_unlock (__crit);			      \
+	 __result = EBADF;						      \
+       }								      \
+     else								      \
+       {								      \
+	 __d.ctty = ctty = _hurd_port_get (&__d.d->ctty, &__d.ctty_ulink);    \
+	 __d.port = port = _hurd_port_locked_get (&__d.d->port, &__d.ulink);  \
+	 __libc_cleanup_push (_hurd_fd_port_use_cleanup, &__d);		      \
+	 _hurd_critical_section_unlock (__crit);			      \
+	 __result = (expr);						      \
+	 __libc_cleanup_pop (1);					      \
+       }								      \
+     __result; })
+
 libc_hidden_proto (_hurd_intern_fd)
 libc_hidden_proto (_hurd_fd_error)
 libc_hidden_proto (_hurd_fd_error_signal)
diff --git a/sysdeps/hurd/include/hurd/port.h b/sysdeps/hurd/include/hurd/port.h
index ca1d2d111a..7828dd6fc1 100644
--- a/sysdeps/hurd/include/hurd/port.h
+++ b/sysdeps/hurd/include/hurd/port.h
@@ -1,6 +1,30 @@
 #ifndef	_HURD_PORT_H
 #include_next <hurd/port.h>
+
 #ifndef _ISOMAC
+struct _hurd_port_use_data
+  {
+     struct hurd_port *p;
+     struct hurd_userlink link;
+     mach_port_t port;
+  };
+
+extern void _hurd_port_use_cleanup (void *arg);
+
+/* Like HURD_PORT_USE, but cleans fd on cancel.  */
+#define	HURD_PORT_USE_CANCEL(portcell, expr)				      \
+  ({ struct _hurd_port_use_data __d;					      \
+     __typeof(expr) __result;						      \
+     void *__crit;							      \
+     __d.p = (portcell);						      \
+     __crit = _hurd_critical_section_lock ();				      \
+     __d.port = port = _hurd_port_get (__d.p, &__d.link);		      \
+     __libc_cleanup_push (_hurd_port_use_cleanup, &__d);		      \
+     _hurd_critical_section_unlock (__crit);				      \
+     __result = (expr);							      \
+     __libc_cleanup_pop (1);						      \
+     __result; })
+
 libc_hidden_proto (_hurd_port_locked_get)
 libc_hidden_proto (_hurd_port_locked_set)
 #ifdef _HURD_PORT_H_HIDDEN_DEF
-- 
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