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=-4.1 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_ADSP_CUSTOM_MED,DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS autolearn=unavailable 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 B9C8AC004C9 for ; Mon, 29 Apr 2019 14:22:29 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 85A972084B for ; Mon, 29 Apr 2019 14:22:29 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="YG27hXjC"; dkim=fail reason="signature verification failed" (2048-bit key) header.d=google.com header.i=@google.com header.b="nSUn3qna" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 85A972084B Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=google.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:To:Subject:Message-ID:Date:From: In-Reply-To:References:MIME-Version:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=c/tsYf1CX5Mip+eL1tQfHb3ZlowqxSR3RBVkMmqzRLQ=; b=YG27hXjC2ITKYW e68Xux0v4p5YGQgaUC2Y0P50Qt0N7xxhzkrvZk4W2VZ0lQ26ztdrbHXWxb1rpdR6W9t0IDDkjn4bL Ge40xAhP0dU4SJ+Ua3HRKWAcp9EwnUSTiWJtKQBkZot//SWbOygGz1AOD3TUKpFSDlyzBiPbk58QL zfOlTCIwwm0WV+FqsWxX68/UCasQh0hQ8ImY162jV/IhqwPSTz6iuSjqz/ZPo+gD5pNOQnSn34tza ekWY9pFw0vDWrGLrbAtebE67KViGqgiwF45sFi5rCN0OIwe0zSJKiZF136t53u/MWbR5qfJbj57id 6Lqtbh0p2F10JPEIsqQg==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1hL7Aq-0007e2-K6; Mon, 29 Apr 2019 14:22:28 +0000 Received: from mail-pg1-x543.google.com ([2607:f8b0:4864:20::543]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1hL7Am-0007d6-7e for linux-arm-kernel@lists.infradead.org; Mon, 29 Apr 2019 14:22:26 +0000 Received: by mail-pg1-x543.google.com with SMTP id 85so5237559pgc.3 for ; Mon, 29 Apr 2019 07:22:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=Q2RFfAyrf9RFoM43ktNZPcHmGWgFL8fnuov2nkBPWS8=; b=nSUn3qnawAssSs6MaxKqsGt7m2rQuwz8iuV7UDRO4XwagTQcUwQLKJChDfpo2Y42Xk dLm04wkPLwmDDcGlfi33gt+mgTjEgazJ0pWoNgMCBCgvVwv5SPNGO+R0wOTcgS/YyTDI MMCTRBCf6Y5X7Op946XZIErDxOVRLAN1uJUSs6b8aMjiipEdz924r1uFPAVVEONFnBC1 eRjcEW3uL1UMy4VUvg8gNA4Pg7nsW7DCRDuZC0iLpBAnBGkKHCDzwyf3Uq04LayvwlmL Hgpedt4edzE9KmfV/TNfyjqaPwOmLbR2KI1O6u2H+6Cx6SK8d3Pu0MrHeMD38gdpjP27 JeSg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=Q2RFfAyrf9RFoM43ktNZPcHmGWgFL8fnuov2nkBPWS8=; b=sjBxTCi1sR04JWd0iKR2ZlLHCelpWBU+Qf4d78i9sE4sU+ufMTo0f7qIgKlsYsbGfT uE6X/JF/mPdMJoGHJWdf41XqzkhMY3r8D+YH85sYhtrXay+7f1TAPKdkhMuo1LkQd6Ms 2lHrHLSawm2QjKJjB9C6t8CREYROkcPr3GGS/Cpac3/z5UggX07FPSZesfpSxMWINfOZ AoUjiEBAZG5eSoud4s0JsB6vGeR1ZbgCv4Pd1hrlEfyirMmwVZ2zn0hMEUNbvY6L4f9v rtYYAcgJ51XfwUxZnUBua+yDtH56kXaWB3BCocoozj/2ubsk6gUvsW3wU2kThC1z3d8Z 8uug== X-Gm-Message-State: APjAAAUztjLHoWodLNuQL8xHY+T8uaWlvTby1rU+AJ3teYmuuqmrSW4g W048AeEe7imKLb3/yB3R5UxNdx/eL3wWIbHLCzDn1Q== X-Google-Smtp-Source: APXvYqyjdyjRGlJ4AtmMgCZd/Nm8Zu8D+p70gtT5fOtGOIKXAcrI3uZOPLT4eOOdJOYGY3S3MZtVzM6xnMJJE/TXbvw= X-Received: by 2002:a62:51c5:: with SMTP id f188mr24041707pfb.239.1556547740003; Mon, 29 Apr 2019 07:22:20 -0700 (PDT) MIME-Version: 1.0 References: <44ad2d0c55dbad449edac23ae46d151a04102a1d.1553093421.git.andreyknvl@google.com> <20190322114357.GC13384@arrakis.emea.arm.com> <20190328141934.38960af0@gandalf.local.home> <20190329103039.GA44339@arrakis.emea.arm.com> <20190426141742.GB54863@arrakis.emea.arm.com> In-Reply-To: <20190426141742.GB54863@arrakis.emea.arm.com> From: Andrey Konovalov Date: Mon, 29 Apr 2019 16:22:08 +0200 Message-ID: Subject: Re: [PATCH v13 04/20] mm, arm64: untag user pointers passed to memory syscalls To: Catalin Marinas X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190429_072224_276953_39FB1100 X-CRM114-Status: GOOD ( 26.43 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , Peter Zijlstra , Will Deacon , Alexei Starovoitov , Linux Memory Management List , Eric Dumazet , Vincenzo Frascino , Ingo Molnar , linux-arch , Daniel Borkmann , Szabolcs Nagy , Dmitry Vyukov , Dave Martin , Evgeniy Stepanov , Kevin Brodsky , Kees Cook , Ruben Ayrapetyan , Ramana Radhakrishnan , Steven Rostedt , Alex Williamson , Arnaldo Carvalho de Melo , Mauro Carvalho Chehab , Linux ARM , Kostya Serebryany , Greg Kroah-Hartman , LKML , Jens Wiklander , Luc Van Oostenryck , Lee Smith , Andrew Morton , "David S. Miller" , "Kirill A . Shutemov" Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Fri, Apr 26, 2019 at 4:17 PM Catalin Marinas wrote: > > On Tue, Apr 02, 2019 at 02:47:34PM +0200, Andrey Konovalov wrote: > > On Fri, Mar 29, 2019 at 11:30 AM Catalin Marinas > > wrote: > > > On Thu, Mar 28, 2019 at 02:19:34PM -0400, Steven Rostedt wrote: > > > > On Thu, 28 Mar 2019 19:10:07 +0100 > > > > Andrey Konovalov wrote: > > > > > > > > > > > Signed-off-by: Andrey Konovalov > > > > > > > --- > > > > > > > ipc/shm.c | 2 ++ > > > > > > > mm/madvise.c | 2 ++ > > > > > > > mm/mempolicy.c | 5 +++++ > > > > > > > mm/migrate.c | 1 + > > > > > > > mm/mincore.c | 2 ++ > > > > > > > mm/mlock.c | 5 +++++ > > > > > > > mm/mmap.c | 7 +++++++ > > > > > > > mm/mprotect.c | 1 + > > > > > > > mm/mremap.c | 2 ++ > > > > > > > mm/msync.c | 2 ++ > > > > > > > 10 files changed, 29 insertions(+) > > > > > > > > > > > > I wonder whether it's better to keep these as wrappers in the arm64 > > > > > > code. > > > > > > > > > > I don't think I understand what you propose, could you elaborate? > > > > > > > > I believe Catalin is saying that instead of placing things like: > > > > > > > > @@ -1593,6 +1593,7 @@ SYSCALL_DEFINE3(shmat, int, shmid, char __user *, shmaddr, int, shmflg) > > > > unsigned long ret; > > > > long err; > > > > > > > > + shmaddr = untagged_addr(shmaddr); > > > > > > > > To instead have the shmaddr set to the untagged_addr() before calling > > > > the system call, and passing the untagged addr to the system call, as > > > > that goes through the arm64 architecture specific code first. > > > > > > Indeed. For example, we already have a SYSCALL_DEFINE6(mmap, ...) in > > > arch/arm64/kernel/sys.c, just add the untagging there. We could do > > > something similar for the other syscalls. I don't mind doing this in the > > > generic code but if it's only needed for arm64, I'd rather keep the > > > generic changes to a minimum. > > > > Do I understand correctly, that I'll need to add ksys_ wrappers for > > each of the memory syscalls, and then redefine them in > > arch/arm64/kernel/sys.c with arm64_ prefix, like it is done for the > > personality syscall right now? This will require generic changes as > > well. > > Yes. My aim is to keep the number of untagged_addr() calls in the > generic code to a minimum (rather than just keeping the generic code > changes small). OK, will do in v14 (despite it still being unclear whether we should do untagging here or not). > > -- > Catalin _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel