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 [170.10.129.124]) by sourceware.org (Postfix) with ESMTPS id DF7853858D20 for ; Mon, 8 Apr 2024 08:05:06 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org DF7853858D20 Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=redhat.com ARC-Filter: OpenARC Filter v1.0.0 sourceware.org DF7853858D20 Authentication-Results: server2.sourceware.org; arc=none smtp.remote-ip=170.10.129.124 ARC-Seal: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1712563509; cv=none; b=FhsvmA8aN5KOPprRkp5z0T8RJgWrdDCrIamterh7W2rHR67F2YWIm0NGzi004JjfI03NXfeSWLYwQPldysHJYIkFTPXP85R+XiDRyBJzgd8tlXlBeM3hU1svo3qrDq86yX6HL92f1gBkA+K/kTeAhrcqLP2JdM7fyUEOhwYEszQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1712563509; c=relaxed/simple; bh=Ogk7xDIG2UiH/eCUPoEYNBXMIY8bcbsjYr6k1PUgNE8=; h=DKIM-Signature:From:To:Subject:Date:Message-ID:MIME-Version; b=bU0VYL58af+s9XB8HxIbuhtKWJCtprQ8rWGLaE0p3ATmDxsY3K5pOnH5JxxWm0N3mhkpj3qzXNGC2g0kkY+St3hnWCNZOj1+eFRzrlG++LfsOQSu+dZjozPhnscxKmFk5lKLTzbQ5aHSlS+eRwf+go9Gd0wrCMqDQEv7uYuPL1E= ARC-Authentication-Results: i=1; server2.sourceware.org DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1712563506; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=oz7T4cHV0mtigfpnTEHGKV8GYzkrx5B9ab3HGxFnWB0=; b=cVCbKI8KqLorUD5Dg8/1dhs5hFX3KBRXE4/2wAc4WXIS9qRf7tUfDOE7kH8MYs1JnzUav1 6xiZLIYQTLiYeYOdAcIemQ/tsZYYZOLlRKMoWFhVsxxla7mISzz49Wq0FChi8r9cn2Y2U2 RAF4rqEkE/eIvyn3OJoIVU6vzXdiMJs= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-349-_A7_l2c1OGe6ix-e4J-XMQ-1; Mon, 08 Apr 2024 04:05:03 -0400 X-MC-Unique: _A7_l2c1OGe6ix-e4J-XMQ-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id AF77B801FB0; Mon, 8 Apr 2024 08:05:02 +0000 (UTC) Received: from oldenburg.str.redhat.com (unknown [10.39.192.59]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 760712026D06; Mon, 8 Apr 2024 08:05:01 +0000 (UTC) From: Florian Weimer To: Szabolcs Nagy Cc: Adhemerval Zanella Netto , Szabolcs Nagy , libc-alpha@sourceware.org Subject: Re: [PATCH] aarch64: Remove ld.so __tls_get_addr plt usage In-Reply-To: <20240406174016.GD3766212@port70.net> (Szabolcs Nagy's message of "Sat, 6 Apr 2024 19:40:16 +0200") References: <20240405123550.1748641-1-adhemerval.zanella@linaro.org> <0af468ae-bf65-4e20-8bd7-af85eba2e5d9@linaro.org> <20240406174016.GD3766212@port70.net> Date: Mon, 08 Apr 2024 10:04:55 +0200 Message-ID: <87frvw1dqw.fsf@oldenburg.str.redhat.com> User-Agent: Gnus/5.13 (Gnus v5.13) MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.4 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain X-Spam-Status: No, score=-5.3 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_NONE,RCVD_IN_MSPIKE_H4,RCVD_IN_MSPIKE_WL,SPF_HELO_NONE,SPF_NONE,TXREP 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: * Szabolcs Nagy: > * Adhemerval Zanella Netto [2024-04-05 13:29:48 -0300]: > >> >> >> On 05/04/24 11:58, Szabolcs Nagy wrote: >> > The 04/05/2024 09:35, Adhemerval Zanella wrote: >> >> Use the hidden alias instead. >> >> >> >> Checked on aarch64-linux-gnu. >> > >> > does this change behaviour in case __tls_get_addr is interposed? >> > >> > >> >> Do we support symbol interposition for symbols in implementation namespace? >> If so, we will need to revert x86 to use the same semantic and document it >> properly. > > i suspect this will partially break the sanitizers > and possibly other similar tools that hook internals > so i hoped at least for better commit msg pointing > out that this is deliberate behaviour change. There is a __tls_get_addr interceptor, but I'm not sure what it does, exactly. If the initial-exec optimization kicks in, this code path isn't even used. I think we should try if removing the indirect call helps. Thanks, Florian