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 X-Spam-Level: X-Spam-Status: No, score=-8.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 38C10C43381 for ; Fri, 22 Mar 2019 15:45:28 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id E636B218FC for ; Fri, 22 Mar 2019 15:45:27 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E636B218FC Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 8B0616B0006; Fri, 22 Mar 2019 11:45:27 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 887F76B0007; Fri, 22 Mar 2019 11:45:27 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 750BA6B0008; Fri, 22 Mar 2019 11:45:27 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from mail-ed1-f72.google.com (mail-ed1-f72.google.com [209.85.208.72]) by kanga.kvack.org (Postfix) with ESMTP id 25C9E6B0006 for ; Fri, 22 Mar 2019 11:45:27 -0400 (EDT) Received: by mail-ed1-f72.google.com with SMTP id e55so1128780edd.6 for ; Fri, 22 Mar 2019 08:45:27 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-original-authentication-results:x-gm-message-state:date:from:to :cc:subject:message-id:references:mime-version:content-disposition :in-reply-to:user-agent; bh=B7QLAOIspGi+pMZ0NRFiNxSwvLuzqH/UGMA7IIsPF0Q=; b=e9tkXA2YgQM3hHutW4Cdfz/IW8AzeXrsZWlZ+KS6UMV8tpzxpxgUCIz5fiZRzzNIuK ornmyE5AbS+iD/MGghnWvhRf08A4L3jzQ6bcKW1/L752LO0X912YQBHJFpfnfJg9Q2z5 ptp64CIbjp+h+FBZZgZeKCFqMC+2fKCFtCDlGFsIE539imICCFZWjkkjz71O1v9ADFnu XxVUl9R+cQknL6m1mArV9tvh7elIay4CS7ValYpxnWRb/GvuRbsD8mFum4jaV7dZXxn1 4DhEPsIPFzKn/YnkZYRouSbO6xqOQziojAmldZd/7afNqunKHh4yNmmnJ0r1lg4+jpiA VVHw== X-Original-Authentication-Results: mx.google.com; spf=pass (google.com: domain of catalin.marinas@arm.com designates 217.140.101.70 as permitted sender) smtp.mailfrom=catalin.marinas@arm.com X-Gm-Message-State: APjAAAWUmSNcz29lnrdpI0lOa4OisuEvylDsoFDvJb335vXzSZhCYP6L FAyaUIzsD01yQG7RV2QnCnIQTsVuvoZRVZTVz9urLR/zAzO4UaVR41v/Ne7EOVCnD+lSFeQyzQf fwgAC8csV3zFSX6fLeq50+aA58Vx9RrhdquHhqwWpaEBM7ZTrPm6aLHerfPGdSFK/OA== X-Received: by 2002:a17:906:d0cb:: with SMTP id bq11mr5968999ejb.185.1553269526705; Fri, 22 Mar 2019 08:45:26 -0700 (PDT) X-Google-Smtp-Source: APXvYqx6iJ8oOwbN3zVQdWX2YTIvgs3CPmnyAb66xxw7MBZYtoHyn/YpG9C3q5tGQ7avjMDgYgkA X-Received: by 2002:a17:906:d0cb:: with SMTP id bq11mr5968962ejb.185.1553269525826; Fri, 22 Mar 2019 08:45:25 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1553269525; cv=none; d=google.com; s=arc-20160816; b=kvC5AqBtvvu4CbPrnR1os9TgoSo1PQkbUGdATZTfUJnGZQ1b8AkqVPxomEiiZOJUAV KJuwRSnd2z8m6JJ/t1+5p4Y2WP/QhdeQls5bofkiuRwap3fF0TrGqZP04ry4Et+jHluu qFpZ9adX9dPdcCcxGqCGsJ/FyCwp068UUhB0wBYN7gFukJG+EzcAgEvHkLvgz9Z0QBrk vKB6ZG8nyU0TC34mo5eyl+JN0fENFBpcdnLs7wVq8uVnQRGp+KwdmMsVcfQZgwYNa2L2 yqbNBgvjVNSOxxQSKCjXjsI8tGCxU/yjzBZcvnde4WOTF58/PdqqCBCir/JChSjd+wYM ebOg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=user-agent:in-reply-to:content-disposition:mime-version:references :message-id:subject:cc:to:from:date; bh=B7QLAOIspGi+pMZ0NRFiNxSwvLuzqH/UGMA7IIsPF0Q=; b=v7OTZco0qpe6cJdH8J3n6SWOpNtsuxOBenFB3JHax48JWWAjkqTmwXGziOKJqYAPLo 3XEVqiAXGanAUsCVP6ZWp65rdShOYOY47+9VqziIRWBTpWUAAx/XejTgY1gyMgKvjsiA 51EUcWB/8IQdNNEebGSTI/FHFkcKGAXPLRU2qELdkoG8tXVQqo2aFYmHpUGnRQWWa4er CAlCKNlLHXZsHrenj1FADwUlXK87ttN9IKKYy7fMW717xAw55FuDsKZl0cXWeQDy6PvE 43wud/cNvJqsZjHS1OS59Kw8y1pKO8+DXZY+quv68pmWbywhHbdvUFIczBFFn0baeJtU jgNg== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of catalin.marinas@arm.com designates 217.140.101.70 as permitted sender) smtp.mailfrom=catalin.marinas@arm.com Received: from foss.arm.com (usa-sjc-mx-foss1.foss.arm.com. [217.140.101.70]) by mx.google.com with ESMTP id s4si163706edx.79.2019.03.22.08.45.25 for ; Fri, 22 Mar 2019 08:45:25 -0700 (PDT) Received-SPF: pass (google.com: domain of catalin.marinas@arm.com designates 217.140.101.70 as permitted sender) client-ip=217.140.101.70; Authentication-Results: mx.google.com; spf=pass (google.com: domain of catalin.marinas@arm.com designates 217.140.101.70 as permitted sender) smtp.mailfrom=catalin.marinas@arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 7227BA78; Fri, 22 Mar 2019 08:45:24 -0700 (PDT) Received: from arrakis.emea.arm.com (arrakis.cambridge.arm.com [10.1.196.78]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 896833F59C; Fri, 22 Mar 2019 08:45:16 -0700 (PDT) Date: Fri, 22 Mar 2019 15:45:14 +0000 From: Catalin Marinas To: Andrey Konovalov Cc: Will Deacon , Mark Rutland , Robin Murphy , Kees Cook , Kate Stewart , Greg Kroah-Hartman , Andrew Morton , Ingo Molnar , "Kirill A . Shutemov" , Shuah Khan , Vincenzo Frascino , Eric Dumazet , "David S. Miller" , Alexei Starovoitov , Daniel Borkmann , Steven Rostedt , Ingo Molnar , Peter Zijlstra , Arnaldo Carvalho de Melo , Alex Deucher , Christian =?iso-8859-1?Q?K=F6nig?= , "David (ChunMing) Zhou" , Yishai Hadas , Mauro Carvalho Chehab , Jens Wiklander , Alex Williamson , linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, linux-arch@vger.kernel.org, netdev@vger.kernel.org, bpf@vger.kernel.org, amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-rdma@vger.kernel.org, linux-media@vger.kernel.org, kvm@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org, Dmitry Vyukov , Kostya Serebryany , Evgeniy Stepanov , Lee Smith , Ramana Radhakrishnan , Jacob Bramley , Ruben Ayrapetyan , Chintan Pandya , Luc Van Oostenryck , Dave Martin , Kevin Brodsky , Szabolcs Nagy Subject: Re: [PATCH v13 11/20] tracing, arm64: untag user pointers in seq_print_user_ip Message-ID: <20190322154513.GQ13384@arrakis.emea.arm.com> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Wed, Mar 20, 2019 at 03:51:25PM +0100, Andrey Konovalov wrote: > This patch is a part of a series that extends arm64 kernel ABI to allow to > pass tagged user pointers (with the top byte set to something else other > than 0x00) as syscall arguments. > > seq_print_user_ip() uses provided user pointers for vma lookups, which > can only by done with untagged pointers. > > Untag user pointers in this function. > > Signed-off-by: Andrey Konovalov > --- > kernel/trace/trace_output.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c > index 54373d93e251..6376bee93c84 100644 > --- a/kernel/trace/trace_output.c > +++ b/kernel/trace/trace_output.c > @@ -370,6 +370,7 @@ static int seq_print_user_ip(struct trace_seq *s, struct mm_struct *mm, > { > struct file *file = NULL; > unsigned long vmstart = 0; > + unsigned long untagged_ip = untagged_addr(ip); > int ret = 1; > > if (s->full) > @@ -379,7 +380,7 @@ static int seq_print_user_ip(struct trace_seq *s, struct mm_struct *mm, > const struct vm_area_struct *vma; > > down_read(&mm->mmap_sem); > - vma = find_vma(mm, ip); > + vma = find_vma(mm, untagged_ip); > if (vma) { > file = vma->vm_file; > vmstart = vma->vm_start; > @@ -388,7 +389,7 @@ static int seq_print_user_ip(struct trace_seq *s, struct mm_struct *mm, > ret = trace_seq_path(s, &file->f_path); > if (ret) > trace_seq_printf(s, "[+0x%lx]", > - ip - vmstart); > + untagged_ip - vmstart); > } > up_read(&mm->mmap_sem); > } How would we end up with a tagged address here? Does "ip" here imply instruction pointer, which we wouldn't tag? -- Catalin