Update hurd/hurdselect.c to be more portable.

Summary of changes:
- Use BAD_TYPECHECK to perform type checking in a cleaner way.
  BAD_TYPECHECK is moved into sysdeps/mach/rpc.h to avoid duplication.
- Remove assertions for mach_msg_type_t since those won't work for
  x86_64.
- Update message structs to use mach_msg_type_t directly.
- Use designated initializers.
Message-Id: <ZFa+roan3ioo0ONM@jupiter.tail36e24.ts.net>
This commit is contained in:
Flavio Cruz 2023-05-06 16:55:10 -04:00 committed by Samuel Thibault
parent e64b7c26d4
commit 84b4a81aeb
4 changed files with 46 additions and 26 deletions

View File

@ -22,6 +22,7 @@
#include <hurd.h>
#include <hurd/fd.h>
#include <hurd/io_request.h>
#include <mach_rpc.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
@ -69,14 +70,6 @@ _hurd_select (int nfds,
sigset_t oset;
struct hurd_sigstate *ss = NULL;
union typeword /* Use this to avoid unkosher casts. */
{
mach_msg_type_t type;
uint32_t word;
};
assert (sizeof (union typeword) == sizeof (mach_msg_type_t));
assert (sizeof (uint32_t) == sizeof (mach_msg_type_t));
if (nfds < 0 || (pollfds == NULL && nfds > FD_SETSIZE))
{
errno = EINVAL;
@ -404,15 +397,15 @@ _hurd_select (int nfds,
struct
{
mach_msg_header_t head;
union typeword err_type;
mach_msg_type_t err_type;
error_t err;
} error;
struct
{
mach_msg_header_t head;
union typeword err_type;
mach_msg_type_t err_type;
error_t err;
union typeword result_type;
mach_msg_type_t result_type;
int result;
} success;
#endif
@ -443,9 +436,14 @@ _hurd_select (int nfds,
/* We got a message. Decode it. */
#ifdef MACH_MSG_TYPE_BIT
const union typeword inttype =
{ type:
{ MACH_MSG_TYPE_INTEGER_T, sizeof (integer_t) * 8, 1, 1, 0, 0 }
static const mach_msg_type_t inttype = {
.msgt_name = MACH_MSG_TYPE_INTEGER_T,
.msgt_size = sizeof (integer_t) * 8,
.msgt_number = 1,
.msgt_inline = TRUE,
.msgt_longform = FALSE,
.msgt_deallocate = FALSE,
.msgt_unused = 0
};
#endif
@ -462,7 +460,7 @@ _hurd_select (int nfds,
&& msg.head.msgh_size >= sizeof msg.error
&& !(msg.head.msgh_bits & MACH_MSGH_BITS_COMPLEX)
#ifdef MACH_MSG_TYPE_BIT
&& msg.error.err_type.word == inttype.word
&& !BAD_TYPECHECK (&msg.error.err_type, &inttype)
#endif
)
{
@ -480,7 +478,7 @@ _hurd_select (int nfds,
occurred. */
if (msg.error.err
#ifdef MACH_MSG_TYPE_BIT
|| msg.success.result_type.word != inttype.word
|| BAD_TYPECHECK (&msg.success.result_type, &inttype)
#endif
|| msg.head.msgh_size != sizeof msg.success)
{

View File

@ -17,6 +17,7 @@
<https://www.gnu.org/licenses/>. */
#include <mach.h>
#include <mach_rpc.h>
#include <mach/mig_errors.h>
#include <mach/mig_support.h>
#include <hurd/signal.h>
@ -28,11 +29,6 @@
# define mig_reply_header_t mig_reply_error_t
#endif
/* Macro used by MIG to cleanly check the type. */
#define BAD_TYPECHECK(type, check) __glibc_unlikely (({ \
union { mach_msg_type_t t; uint32_t w; } _t, _c; \
_t.t = *(type); _c.t = *(check);_t.w != _c.w; }))
error_t
_hurd_intr_rpc_mach_msg (mach_msg_header_t *msg,
mach_msg_option_t option,

View File

@ -28,6 +28,7 @@
#include <stdint.h>
#include <hurd/ioctl.h>
#include <mach/mig_support.h>
#include <mach_rpc.h>
#include <sysdep-cancel.h>
#include <hurd/ioctls.defs>
@ -35,11 +36,6 @@
#define msg_align(x) ALIGN_UP (x, __alignof__ (uintptr_t))
#define typesize(type) (1 << (type))
/* Macro used by MIG to cleanly check the type. */
#define BAD_TYPECHECK(type, check) __glibc_unlikely (({ \
union { mach_msg_type_t t; uint32_t w; } _t, _c; \
_t.t = *(type); _c.t = *(check);_t.w != _c.w; }))
/* Perform the I/O control operation specified by REQUEST on FD.
The actual type and use of ARG and the return value depend on REQUEST. */
int

30
sysdeps/mach/mach_rpc.h Normal file
View File

@ -0,0 +1,30 @@
/* Macros for handling Mach RPC messages.
Copyright (C) 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/message.h>
/* Macro used by MIG to cleanly check the type. */
#define BAD_TYPECHECK(type, check) __glibc_unlikely (({ \
union { mach_msg_type_t t; uint32_t w; } _t, _c; \
_t.t = *(type); _c.t = *(check);_t.w != _c.w; }))
/* TODO: add this assertion for x86_64. */
#ifndef __x86_64__
_Static_assert (sizeof (uint32_t) == sizeof (mach_msg_type_t),
"mach_msg_type_t needs to be the same size as uint32_t");
#endif