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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 0BBA7C27C79 for ; Thu, 20 Jun 2024 09:10:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=GZSfcZG+KL4h8GQs6NMrIyrvzuT3/K8Q28tO1U3u9w4=; b=D9dReWLe1lkJ2uo4s6Cap7/jO4 0UJk3hKZQVxrzHKxTkD2WXNJV38ZPS9WxHn9gOPtRPm1Byn6wd1D927iKauwMOkRniN3GZnfa66P1 MlNmN5UQGGLvRJJAd4vuDJOJN0nx4ZI/q5rUOKtLOOxYdr0IUq5TknaPqoEiN18e8c+ZS2ImmnSyW NqdujNfpfJtAcko7nYaBx/I11hO9Ib2CclrqvtW7pPwW3LMZAYmh+d+aGrQTGBG2NtO6p42wwzrWk 0g/TX820deRok7Y53pmROqBOUtGK1t0uK9XyLar0TvuCRATq9DgvG0q6F27YgffZGq9QauLQq7EAp HzMouvwg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1sKDno-00000004Kcy-2NDN; Thu, 20 Jun 2024 09:09:56 +0000 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1sKDnk-00000004KbM-2JIg for linux-arm-kernel@lists.infradead.org; Thu, 20 Jun 2024 09:09:54 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1718874591; 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=GZSfcZG+KL4h8GQs6NMrIyrvzuT3/K8Q28tO1U3u9w4=; b=E/W3sDG0AhBQJakslkRn/qBLZ45xHeuVVr2e+63Z3YmGDEfM4oRDfXc6KjFlqsxSfjajii ClESz6xLP6tbebbI5Tq5VbQdqWr5z372Obp6TK5u//zsPOfq4D9bZDlfyN/E6L3rELBcYH pt1y6P3CbitCoRBGDA5i1dnjNwNY6+A= Received: from mx-prod-mc-03.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-189-LhuqOdFhOj-bvsFoYhn1oQ-1; Thu, 20 Jun 2024 05:09:46 -0400 X-MC-Unique: LhuqOdFhOj-bvsFoYhn1oQ-1 Received: from mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.4]) (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 mx-prod-mc-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 6414D19560B1; Thu, 20 Jun 2024 09:09:44 +0000 (UTC) Received: from dhcp-27-174.brq.redhat.com (unknown [10.45.226.26]) by mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with SMTP id EF5463000218; Thu, 20 Jun 2024 09:09:39 +0000 (UTC) Received: by dhcp-27-174.brq.redhat.com (nbSMTP-1.00) for uid 1000 oleg@redhat.com; Thu, 20 Jun 2024 11:08:13 +0200 (CEST) Date: Thu, 20 Jun 2024 11:08:07 +0200 From: Oleg Nesterov To: Tiezhu Yang Cc: Will Deacon , Mark Rutland , Catalin Marinas , Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Namhyung Kim , linux-arm-kernel@lists.infradead.org, linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] arm64: hw_breakpoint: Save privilege of access control via ptrace Message-ID: <20240620090807.GC30070@redhat.com> References: <20240618071010.11214-1-yangtiezhu@loongson.cn> <20240619151524.GB24240@redhat.com> <9cc6d314-2431-c1b5-3d46-63c0ac80ed4d@loongson.cn> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <9cc6d314-2431-c1b5-3d46-63c0ac80ed4d@loongson.cn> User-Agent: Mutt/1.5.24 (2015-08-30) X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.4 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240620_020952_674634_5E62E0A3 X-CRM114-Status: GOOD ( 14.43 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 06/20, Tiezhu Yang wrote: > > On 06/19/2024 11:15 PM, Oleg Nesterov wrote: > >>--- a/include/uapi/linux/perf_event.h > >>+++ b/include/uapi/linux/perf_event.h > >>@@ -467,6 +467,7 @@ struct perf_event_attr { > >> __u32 wakeup_watermark; /* bytes before wakeup */ > >> }; > >> > >>+ __u8 bp_priv; > >> __u32 bp_type; > > > >Is it safe to add the new member in the middle of uapi struct? > >This will break userspace... > > Let me put the new member "bp_priv" at the end of uapi struct > perf_event_attr in the next version if you are OK with it. And add PERF_ATTR_SIZE_VER9 ? Well, you can safely ignore me, you should ask the maintainers ;) But to me the very idea of arm64-specific and "kernel only" member in perf_event_attr looks a bit strange. Oleg.