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 ESMTP id 3F3CD3893661 for ; Tue, 6 Apr 2021 15:55:31 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 3F3CD3893661 Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-98-Y_HPiLxjN4i1sMVS1l8qkw-1; Tue, 06 Apr 2021 11:55:26 -0400 X-MC-Unique: Y_HPiLxjN4i1sMVS1l8qkw-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 86EAB800D53; Tue, 6 Apr 2021 15:55:25 +0000 (UTC) Received: from oldenburg.str.redhat.com (ovpn-112-12.rdu2.redhat.com [10.10.112.12]) by smtp.corp.redhat.com (Postfix) with ESMTPS id C53855DAA5; Tue, 6 Apr 2021 15:55:24 +0000 (UTC) From: Florian Weimer To: libc-alpha@sourceware.org Cc: Stefan Liebler Subject: s390x: Diagnose missing VXE at run time if required at build time Date: Tue, 06 Apr 2021 17:55:37 +0200 Message-ID: <87k0pfmmpy.fsf@oldenburg.str.redhat.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.1 (gnu/linux) MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain X-Spam-Status: No, score=-12.4 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, RCVD_IN_MSPIKE_H4, RCVD_IN_MSPIKE_WL, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) 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: Tue, 06 Apr 2021 15:55:32 -0000 It turns out that if glibc is built with -march=z14, it is still possible to run up to dl_platform_init on z13 CPUs. This means we can add a diagnostic to glibc, notifying the user that the CPU is too old. The check is based on the way GCC sets the __LONG_DOUBLE_VX__ preprocessor macro: s390_def_or_undef_macro ( pfile, [] (const struct cl_target_option *opts) { return TARGET_VXE_P (opts); }, old_opts, opts, "__LONG_DOUBLE_VX__", "__LONG_DOUBLE_VX__"); diff --git a/sysdeps/s390/s390-64/dl-machine.h b/sysdeps/s390/s390-64/dl-machine.h index 543361c83637c071..deaf37951206fb7c 100644 --- a/sysdeps/s390/s390-64/dl-machine.h +++ b/sysdeps/s390/s390-64/dl-machine.h @@ -235,6 +235,12 @@ _dl_start_user:\n\ static inline void __attribute__ ((unused)) dl_platform_init (void) { +#ifdef __LONG_DOUBLE_VX__ + if (!(GLRO(dl_hwcap) & HWCAP_S390_VXE)) + _dl_fatal_printf ("\ +Fatal glibc error: CPU lacks VXE support (z14 or later required)\n"); +#endif + if (GLRO(dl_platform) != NULL && *GLRO(dl_platform) == '\0') /* Avoid an empty string which would disturb us. */ GLRO(dl_platform) = NULL;