glibc/sysdeps/mach/hurd/mig-reply.c
Sergey Bugaev 4e506f67cb hurd: Replace reply port with a dead name on failed interruption
If we're trying to interrupt an interruptible RPC, but the server fails
to respond to our __interrupt_operation () call, we instead destroy the
reply port we were expecting the reply to the RPC on.

Instead of deallocating the name completely, replace it with a dead
name, so the name won't get reused for some other right, and deallocate
it in _hurd_intr_rpc_mach_msg once we return from the signal handler.

Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
Message-Id: <20230429201822.2605207-4-bugaevc@gmail.com>
2023-05-01 03:18:48 +02:00

108 lines
3.1 KiB
C

/* Copyright (C) 1994-2023 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 <mach/mig_support.h>
#include <tls.h>
/* These functions are called by MiG-generated code. */
#if !defined (SHARED) || IS_IN (rtld)
mach_port_t __hurd_reply_port0;
#endif
static mach_port_t
get_reply_port (void)
{
#if !defined (SHARED) || IS_IN (rtld)
if (__LIBC_NO_TLS ())
return __hurd_reply_port0;
#endif
return THREAD_GETMEM (THREAD_SELF, reply_port);
}
static void
set_reply_port (mach_port_t port)
{
#if !defined (SHARED) || IS_IN (rtld)
if (__LIBC_NO_TLS ())
__hurd_reply_port0 = port;
else
#endif
THREAD_SETMEM (THREAD_SELF, reply_port, port);
}
/* Called by MiG to get a reply port. */
mach_port_t
__mig_get_reply_port (void)
{
mach_port_t port = get_reply_port ();
if (__glibc_unlikely (port == MACH_PORT_NULL))
{
port = __mach_reply_port ();
set_reply_port (port);
}
return port;
}
weak_alias (__mig_get_reply_port, mig_get_reply_port)
libc_hidden_def (__mig_get_reply_port)
/* Called by MiG to deallocate the reply port. */
void
__mig_dealloc_reply_port (mach_port_t arg)
{
error_t err;
mach_port_t port = get_reply_port ();
set_reply_port (MACH_PORT_NULL); /* So the mod_refs RPC won't use it. */
assert (port == arg);
if (!MACH_PORT_VALID (port))
return;
err = __mach_port_mod_refs (__mach_task_self (), port,
MACH_PORT_RIGHT_RECEIVE, -1);
if (err == KERN_INVALID_RIGHT)
/* It could be that during signal handling, the receive right had been
replaced with a dead name. */
err = __mach_port_mod_refs (__mach_task_self (), port,
MACH_PORT_RIGHT_DEAD_NAME, -1);
assert_perror (err);
}
weak_alias (__mig_dealloc_reply_port, mig_dealloc_reply_port)
libc_hidden_def (__mig_dealloc_reply_port)
/* Called by mig interfaces when done with a port. Used to provide the
same interface as needed when a custom allocator is used. */
void
__mig_put_reply_port(mach_port_t port)
{
/* Do nothing. */
}
weak_alias (__mig_put_reply_port, mig_put_reply_port)
/* Called at startup with STACK == NULL. When per-thread variables are set
up, this is called again with STACK set to the new stack being switched
to, where per-thread variables should be set up. */
void
__mig_init (void *stack)
{
/* Do nothing. */
}
weak_alias (__mig_init, mig_init)
libc_hidden_def (__mig_init)