From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B77C7C4167B for ; Fri, 2 Dec 2022 12:55:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233528AbiLBMzG (ORCPT ); Fri, 2 Dec 2022 07:55:06 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54444 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232971AbiLBMzE (ORCPT ); Fri, 2 Dec 2022 07:55:04 -0500 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6759DC5E0D for ; Fri, 2 Dec 2022 04:54:11 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1669985650; 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=lc596KyOYqvjrnPcaKRdpq0W8UiV7G21GOZD+y7P6/w=; b=RVTyIU5cOiTbNZ95AUGdv0BCHeMJSVUawHgKWzB0PMv3UCJ9WdiUC7gSLL/QvXn612ude3 uPxKXEb3bF0hFCw2Bwr0xGzY599xMyVvqIB8tYzgKMQ8Lpfj3ZlXiYz25vSvKYla4UUW9r PQ0OzjAjae+QK3dxzsXIldvM65fT0Bg= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-615-1VQkJIyWM2KTaALtrRYEYA-1; Fri, 02 Dec 2022 07:54:07 -0500 X-MC-Unique: 1VQkJIyWM2KTaALtrRYEYA-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id E63D8185A78F; Fri, 2 Dec 2022 12:54:06 +0000 (UTC) Received: from dhcp-27-174.brq.redhat.com (ovpn-194-178.brq.redhat.com [10.40.194.178]) by smtp.corp.redhat.com (Postfix) with SMTP id 16E462166B2A; Fri, 2 Dec 2022 12:54:04 +0000 (UTC) Received: by dhcp-27-174.brq.redhat.com (nbSMTP-1.00) for uid 1000 oleg@redhat.com; Fri, 2 Dec 2022 13:54:06 +0100 (CET) Date: Fri, 2 Dec 2022 13:54:04 +0100 From: Oleg Nesterov To: Thomas Gleixner Cc: Andrew Morton , Masami Hiramatsu , Denys Vlasenko , Seiji Nishikawa , x86@kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] uprobes/x86: allow to probe a "nop" insn with 0x66 prefix Message-ID: <20221202125401.GA16230@redhat.com> References: <20221201142644.GA27185@redhat.com> <871qpiqaz3.ffs@tglx> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <871qpiqaz3.ffs@tglx> User-Agent: Mutt/1.5.24 (2015-08-30) X-Scanned-By: MIMEDefang 3.1 on 10.11.54.6 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/02, Thomas Gleixner wrote: > > On Thu, Dec 01 2022 at 15:26, Oleg Nesterov wrote: > > > From: Denys Vlasenko > > > > Intel icc -hotpatch inserts 2-byte "0x66 0x90" NOP at the start of each > > function to reserve extra space for hot-patching, and currently it is not > > possible to probe these functions because branch_setup_xol_ops() wrongly > > nacks NOP with REP prefix. > > > > Fixes: 250bbd12c2fe ("uprobes/x86: Refuse to attach uprobe to "word-sized" branch insns") > > Reported-by: Seiji Nishikawa > > Signed-off-by: Oleg Nesterov > > The SOB chain is invalid as it lacks the author's signoff. Denys, can we have your signed-off-by?