From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from eggs.gnu.org (eggs.gnu.org [IPv6:2001:470:142:3::10]) by sourceware.org (Postfix) with ESMTPS id B454A3858422 for ; Sat, 6 May 2023 21:11:11 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org B454A3858422 Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=gnu.org Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=gnu.org Received: from fencepost.gnu.org ([2001:470:142:3::e]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pvPBP-0005wY-6u; Sat, 06 May 2023 17:11:11 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=gnu.org; s=fencepost-gnu-org; h=In-Reply-To:MIME-Version:References:Subject:To:From: Date; bh=fsGmX+A30Bt/2yWbF6aJJNz7jrEWpcAdNyL/LE0ApBs=; b=ef3dY3kdqpiJnWC4+KDR rJ+90jUnlXTVGCGAmP8jMUSljW8sAhdv2tzw+/kJ6LDRisK4lrTXzuNb1hDlS510bEDf3n/35X6An rGdlGFxknVv9wTHvWqiI/IiItepDPeyY4pkimlAjnrNmyMj0oFXLDfHdhDuSebqq8moW7kDLYKss2 cnAnY4iF7Fx61vDx35YnenCV4dO84ZOZnbqVMEnemQxxSQGhmLvPcHxAoXHf5Yfu3ziMTqlyhavyQ iYOuoIS6SJw490H9ayYrZylE/p6RL/XAzfTSbXCwD7s21mWAutkIFbZGmcYezeNJMjNf6jVXnIJdr MdeEE6G9GsBx7Q==; Received: from lfbn-bor-1-1163-184.w92-158.abo.wanadoo.fr ([92.158.138.184] helo=begin.home) by fencepost.gnu.org with esmtpsa (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pvPBP-0000I5-0F; Sat, 06 May 2023 17:11:11 -0400 Received: from samy by begin.home with local (Exim 4.96) (envelope-from ) id 1pvPBM-00BBVY-2j; Sat, 06 May 2023 23:11:08 +0200 Date: Sat, 6 May 2023 23:11:08 +0200 From: Samuel Thibault To: Flavio Cruz Cc: bug-hurd@gnu.org, libc-alpha@sourceware.org Subject: Re: [PATCH glibc] Update hurd/hurdselect.c to be more portable. Message-ID: <20230506211108.v4j4stfz5a5gfjwy@begin> Mail-Followup-To: Flavio Cruz , bug-hurd@gnu.org, libc-alpha@sourceware.org References: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Organization: I am not organized User-Agent: NeoMutt/20170609 (1.8.3) X-Spam-Status: No, score=-12.7 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,GIT_PATCH_0,KAM_SHORT,SPF_HELO_PASS,SPF_PASS,TXREP,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: Applied, thanks! Flavio Cruz, le sam. 06 mai 2023 16:55:10 -0400, a ecrit: > 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. > --- > hurd/hurdselect.c | 30 ++++++++++++++---------------- > hurd/intr-msg.c | 6 +----- > sysdeps/mach/hurd/ioctl.c | 6 +----- > sysdeps/mach/mach_rpc.h | 31 +++++++++++++++++++++++++++++++ > 4 files changed, 47 insertions(+), 26 deletions(-) > create mode 100644 sysdeps/mach/mach_rpc.h > > diff --git a/hurd/hurdselect.c b/hurd/hurdselect.c > index 08fcc92170..9630cae474 100644 > --- a/hurd/hurdselect.c > +++ b/hurd/hurdselect.c > @@ -22,6 +22,7 @@ > #include > #include > #include > +#include > #include > #include > #include > @@ -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) > { > diff --git a/hurd/intr-msg.c b/hurd/intr-msg.c > index b535397bfb..bc1f43d383 100644 > --- a/hurd/intr-msg.c > +++ b/hurd/intr-msg.c > @@ -17,6 +17,7 @@ > . */ > > #include > +#include > #include > #include > #include > @@ -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, > diff --git a/sysdeps/mach/hurd/ioctl.c b/sysdeps/mach/hurd/ioctl.c > index 66daaa751e..752cfa60f4 100644 > --- a/sysdeps/mach/hurd/ioctl.c > +++ b/sysdeps/mach/hurd/ioctl.c > @@ -28,6 +28,7 @@ > #include > #include > #include > +#include > #include > > #include > @@ -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 > diff --git a/sysdeps/mach/mach_rpc.h b/sysdeps/mach/mach_rpc.h > new file mode 100644 > index 0000000000..ff1ee1cae9 > --- /dev/null > +++ b/sysdeps/mach/mach_rpc.h > @@ -0,0 +1,31 @@ > +/* 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 > + . */ > + > +#include > + > +/* 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 > + > -- > 2.39.2 > -- Samuel --- Pour une évaluation indépendante, transparente et rigoureuse ! Je soutiens la Commission d'Évaluation de l'Inria.