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 C48B1C2BA18 for ; Thu, 20 Jun 2024 09:30:32 +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=dY8BLS5292leOm/P+eO8Sa3RcLAKz7+rcLO9fC+sRo0=; b=0MmnOJVMVbLTltKlh9PIKnprC2 39X9jsfzHUGADEdMjzHQt7Up6qaU5NswKcLkKg9X/nWtnn1Xlbbh3+SBSpyFoV0dCzUpPtdpfVORL mcP/9tBRlw6kn1cQnK6w8cdhYy6T/BF9jTfwFO6cWjGc8Th8XSngYTeMr0hc1AAZn5YWbfaX7W0XB q1QnDKmbSzqkbeNmxKy7fFqqvu7gxZiF3gsVH6s9WL80sxXoA7zVH5RDvFKEZR5skZhce4EFYoQsu xPbZbUCyE05PudNNOB6YS44P/qSyzKF0C4uRGHvXWB+H66jI82/M2Kn7H1AjWIS/3C1+O7YrnM8BB KxstFkqw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1sKE7W-00000004OP1-1q3y; Thu, 20 Jun 2024 09:30:18 +0000 Received: from dfw.source.kernel.org ([139.178.84.217]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1sKE7T-00000004OO0-2V0I for linux-arm-kernel@lists.infradead.org; Thu, 20 Jun 2024 09:30:16 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by dfw.source.kernel.org (Postfix) with ESMTP id C76686211F; Thu, 20 Jun 2024 09:30:13 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 70492C2BD10; Thu, 20 Jun 2024 09:30:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1718875813; bh=Fdm3uwDH8kPloDZ5bbG8L+LSca1yLBAjSbkLrX2rK1Q=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=r1VxdkgCtotLfCQosH9x004FEmXRGwpFwv196rVqL5qCnxEkEx5pFH27m76s20f47 noaHZ7Kdjj3QiUrm23CXO3QP+ekPzEo7BGNv8SoPWR+y6uJRA0mzaWt+MtRhvVriUn maF93cK9ptS37J8iAEexMaOtOHP0HfaA3biH97WEU5ef52b9o/TndW+hog6g7PRtzR CCpGWP3K4NbKJs3HkfFNXfQpcYG4crVSqwZyMA4f6ORFXwvP+Wd+oeR/1pUAEXr4Tt b8HmSiukskOsxNoF+MThhSXEa/d8Vofdyh1irv9wzOwr1n6Q0XWv81Ky8wZhJ8vfvo PtaoMGht7mOQQ== Date: Thu, 20 Jun 2024 10:30:07 +0100 From: Will Deacon To: Oleg Nesterov Cc: Tiezhu Yang , 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: <20240620093007.GA4464@willie-the-truck> References: <20240618071010.11214-1-yangtiezhu@loongson.cn> <20240619151524.GB24240@redhat.com> <9cc6d314-2431-c1b5-3d46-63c0ac80ed4d@loongson.cn> <20240620090807.GC30070@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240620090807.GC30070@redhat.com> User-Agent: Mutt/1.10.1 (2018-07-13) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240620_023015_724800_2F1C7229 X-CRM114-Status: GOOD ( 16.82 ) 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 Thu, Jun 20, 2024 at 11:08:07AM +0200, Oleg Nesterov wrote: > 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. Yeah, completely agreed. Will