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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8AD3DC433EF for ; Wed, 29 Sep 2021 12:02:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6FF82613D1 for ; Wed, 29 Sep 2021 12:02:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1343629AbhI2MDt convert rfc822-to-8bit (ORCPT ); Wed, 29 Sep 2021 08:03:49 -0400 Received: from mail-oi1-f182.google.com ([209.85.167.182]:45788 "EHLO mail-oi1-f182.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1343879AbhI2MDe (ORCPT ); Wed, 29 Sep 2021 08:03:34 -0400 Received: by mail-oi1-f182.google.com with SMTP id v10so2528900oic.12; Wed, 29 Sep 2021 05:01:54 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc:content-transfer-encoding; bh=DPTFjBNMYZsH/LoF0h0iC/ghN40ymuV4zkUVlZxxnn4=; b=nFsj8U7fsXNHpID73JvNvKeoev19i8s8Qc6aNmtgTy4h1ZJ12fo5OJUqFMeydby5q0 r3XQ7gk6BdmgTayJGmj3OyjutX1cSdGR/9YXDA5f17ybkj5kFXCPQPkLWTw3rYB6rv3Y iNFiyBdnY3VeTOtAgRQ7En8pQ9R7A2VaJgosggcZ6kwzxei42AbsyRBPJNyRx9EBLpV6 YMmTzSIANmULQNsnM/KuSRWkBxSyF2qaoWJkbXbvJ1YYHqBsPwA38xxUGPCy/yinc9dX 0pzHmsuW3qvFMDCjRoUazXbzN70F9YgiBNkZUJtlQCrG4yUG3a+uT8RfHJTNi9GdXIoy h+0Q== X-Gm-Message-State: AOAM53072xOp1CuP/KX0hGBdNG+WNiiKjgOCXHTI4QRyyIjuOYC8iu8h tPxUw9OvakhznHTsJjBA5Db86C9UKnZNLZfnqHMy1GKc X-Google-Smtp-Source: ABdhPJxoNw5TPiy7tXyGhRFCBqyoslPg2WsTrtX+8FsVJTpHKJufbkxvO43p83wgr2KyAiyOScD/EBdm7rFq04tgduc= X-Received: by 2002:a05:6808:178c:: with SMTP id bg12mr8017044oib.157.1632916913639; Wed, 29 Sep 2021 05:01:53 -0700 (PDT) MIME-Version: 1.0 References: <20210927121338.938994-1-arnd@kernel.org> <92b02547-3aa5-537f-a782-7a25854d88fe@intel.com> In-Reply-To: From: "Rafael J. Wysocki" Date: Wed, 29 Sep 2021 14:01:41 +0200 Message-ID: Subject: Re: [PATCH] ACPI: avoid NULL pointer arithmetic To: "Moore, Robert" Cc: "Wysocki, Rafael J" , Arnd Bergmann , Arnd Bergmann , Nathan Chancellor , Nick Desaulniers , "linux-acpi@vger.kernel.org" , "devel@acpica.org" , "linux-kernel@vger.kernel.org" , "llvm@lists.linux.dev" , Len Brown , "Rafael J. Wysocki" Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8BIT Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Sep 28, 2021 at 10:39 PM Moore, Robert wrote: > > I can take this patch as-is, I think. I'll try for the next acpica release later this week. Thanks! > -----Original Message----- > From: Wysocki, Rafael J > Sent: Tuesday, September 28, 2021 10:44 AM > To: Arnd Bergmann ; Moore, Robert > Cc: Arnd Bergmann ; Nathan Chancellor ; Nick Desaulniers ; Erik Kaneda ; linux-acpi@vger.kernel.org; devel@acpica.org; linux-kernel@vger.kernel.org; llvm@lists.linux.dev; Len Brown ; Rafael J. Wysocki > Subject: Re: [PATCH] ACPI: avoid NULL pointer arithmetic > > Bob, this is ACPICA material. > > Would it be possible to apply this to the upstream from the patch or do you need a PR for this? > > On 9/27/2021 2:13 PM, Arnd Bergmann wrote: > > From: Arnd Bergmann > > > > There are some very old macros for doing an open-coded offsetof() and > > cast between pointer and integer in ACPI headers. clang-14 now > > complains about these: > > > > drivers/acpi/acpica/tbfadt.c:86:3: error: performing pointer subtraction with a null pointer has undefined behavior [-Werror,-Wnull-pointer-subtraction] > > ACPI_FADT_OFFSET(pm_timer_block), > > ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > > include/acpi/actbl.h:376:47: note: expanded from macro 'ACPI_FADT_OFFSET' > > #define ACPI_FADT_OFFSET(f) (u16) ACPI_OFFSET (struct acpi_table_fadt, f) > > > > ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > > include/acpi/actypes.h:511:41: note: expanded from macro 'ACPI_OFFSET' > > #define ACPI_OFFSET(d, f) ACPI_PTR_DIFF (&(((d *) 0)->f), (void *) 0) > > > > ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > > include/acpi/actypes.h:505:79: note: expanded from macro 'ACPI_PTR_DIFF' > > #define ACPI_PTR_DIFF(a, b) ((acpi_size) (ACPI_CAST_PTR (u8, (a)) - ACPI_CAST_PTR (u8, (b)))) > > > > ^ ~~~~~~~~~~~~~~~~~~~~~~~ Convert them to the modern equivalents. > > > > Signed-off-by: Arnd Bergmann > > --- > > include/acpi/actypes.h | 4 ++-- > > 1 file changed, 2 insertions(+), 2 deletions(-) > > > > diff --git a/include/acpi/actypes.h b/include/acpi/actypes.h index > > 92c71dfce0d5..285bc7b73de3 100644 > > --- a/include/acpi/actypes.h > > +++ b/include/acpi/actypes.h > > @@ -507,8 +507,8 @@ typedef u64 acpi_integer; > > /* Pointer/Integer type conversions */ > > > > #define ACPI_TO_POINTER(i) ACPI_CAST_PTR (void, (acpi_size) (i)) > > -#define ACPI_TO_INTEGER(p) ACPI_PTR_DIFF (p, (void *) 0) > > -#define ACPI_OFFSET(d, f) ACPI_PTR_DIFF (&(((d *) 0)->f), (void *) 0) > > +#define ACPI_TO_INTEGER(p) ((uintptr_t)(p)) > > +#define ACPI_OFFSET(d, f) offsetof(d, f) > > #define ACPI_PHYSADDR_TO_PTR(i) ACPI_TO_POINTER(i) > > #define ACPI_PTR_TO_PHYSADDR(i) ACPI_TO_INTEGER(i) > > > >