From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by sourceware.org (Postfix) with ESMTPS id CB006385842B for ; Wed, 27 Apr 2022 18:44:39 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org CB006385842B Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-590-roMaa6ZkNcq98kMf2K-wSg-1; Wed, 27 Apr 2022 14:44:38 -0400 X-MC-Unique: roMaa6ZkNcq98kMf2K-wSg-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.rdu2.redhat.com [10.11.54.8]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id BF0DA29AA2ED; Wed, 27 Apr 2022 18:44:37 +0000 (UTC) Received: from oldenburg.str.redhat.com (unknown [10.39.193.187]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 0B3C9C28118; Wed, 27 Apr 2022 18:44:36 +0000 (UTC) From: Florian Weimer To: Adhemerval Zanella Cc: Adhemerval Zanella via Libc-alpha Subject: Re: [PATCH v2 2/4] Consolidate stdio-lock.h References: <20220426191523.833171-1-adhemerval.zanella@linaro.org> <20220426191523.833171-3-adhemerval.zanella@linaro.org> <87o80mhd4u.fsf@oldenburg.str.redhat.com> <874k2ee79d.fsf@oldenburg.str.redhat.com> Date: Wed, 27 Apr 2022 20:44:35 +0200 In-Reply-To: (Adhemerval Zanella's message of "Wed, 27 Apr 2022 15:35:18 -0300") Message-ID: <87o80mcqng.fsf@oldenburg.str.redhat.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.2 (gnu/linux) MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.85 on 10.11.54.8 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain X-Spam-Status: No, score=-11.7 required=5.0 tests=BAYES_00, DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, GIT_PATCH_0, RCVD_IN_DNSWL_LOW, SPF_HELO_NONE, SPF_NONE, TXREP autolearn=ham autolearn_force=no version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on server2.sourceware.org X-BeenThere: libc-alpha@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libc-alpha mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 27 Apr 2022 18:44:40 -0000 * Adhemerval Zanella: > You are right. The change now uses __libc_cleanup_region_start from > libc-lock.h instead of the cleanup version. I am not sure about > hardening, but afaiu __libc_cleanup_push_defer should handle C++ > unwinding for fopencookie. No, C++ unwinding will right go through these frames. We only interleave in the other direction (pthread_cancel unwinding running C++ destructors). > It seems that the Hurd version is indeed to the best option, so I think for > generic it would be better to just use: > > diff --git a/sysdeps/generic/stdio-lock.h b/sysdeps/generic/stdio-lock.h > index 14cf458bdd..a42131f5a5 100644 > --- a/sysdeps/generic/stdio-lock.h > +++ b/sysdeps/generic/stdio-lock.h > @@ -45,20 +45,12 @@ __libc_lock_define_recursive (typedef, _IO_lock_t) > #define _IO_cleanup_region_end(_doit) \ > __libc_cleanup_region_end (_doit) > > -#if defined _LIBC && IS_IN (libc) > - > -# ifdef __EXCEPTIONS > -# define _IO_acquire_lock(_fp) \ > +#define _IO_acquire_lock(_fp) \ > do { \ > FILE *_IO_acquire_lock_file \ > __attribute__((cleanup (_IO_acquire_lock_fct))) \ > = (_fp); \ > _IO_flockfile (_IO_acquire_lock_file); > -# else > -# define _IO_acquire_lock(_fp) _IO_acquire_lock_needs_exceptions_enabled > -# endif > -# define _IO_release_lock(_fp) ; } while (0) > - > -#endif > +#define _IO_release_lock(_fp) ; } while (0) > > #endif /* stdio-lock.h */ I suppose so. Thanks, Florian