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=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 63CBAC43218 for ; Tue, 11 Jun 2019 10:19:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4386B205F4 for ; Tue, 11 Jun 2019 10:19:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2405393AbfFKKT1 (ORCPT ); Tue, 11 Jun 2019 06:19:27 -0400 Received: from foss.arm.com ([217.140.110.172]:57800 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2404766AbfFKKT1 (ORCPT ); Tue, 11 Jun 2019 06:19:27 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id B8662337; Tue, 11 Jun 2019 03:19:26 -0700 (PDT) Received: from [10.1.29.141] (e121487-lin.cambridge.arm.com [10.1.29.141]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id AC6DF3F557; Tue, 11 Jun 2019 03:21:07 -0700 (PDT) Subject: Re: [PATCH 03/17] mm/nommu: fix the MAP_UNINITIALIZED flag To: Christoph Hellwig , Palmer Dabbelt Cc: Damien Le Moal , linux-riscv@lists.infradead.org, uclinux-dev@uclinux.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <20190610221621.10938-1-hch@lst.de> <20190610221621.10938-4-hch@lst.de> From: Vladimir Murzin Message-ID: Date: Tue, 11 Jun 2019 11:19:23 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.7.0 MIME-Version: 1.0 In-Reply-To: <20190610221621.10938-4-hch@lst.de> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 6/10/19 11:16 PM, Christoph Hellwig wrote: > We can't expose UAPI symbols differently based on CONFIG_ symbols, as > userspace won't have them available. Instead always define the flag, > but only repsect it based on the config option. ^^^^^^^ respect > > Signed-off-by: Christoph Hellwig > --- > arch/xtensa/include/uapi/asm/mman.h | 6 +----- > include/uapi/asm-generic/mman-common.h | 8 +++----- > mm/nommu.c | 4 +++- > 3 files changed, 7 insertions(+), 11 deletions(-) FWIW: Reviewed-by: Vladimir Murzin > > diff --git a/arch/xtensa/include/uapi/asm/mman.h b/arch/xtensa/include/uapi/asm/mman.h > index be726062412b..ebbb48842190 100644 > --- a/arch/xtensa/include/uapi/asm/mman.h > +++ b/arch/xtensa/include/uapi/asm/mman.h > @@ -56,12 +56,8 @@ > #define MAP_STACK 0x40000 /* give out an address that is best suited for process/thread stacks */ > #define MAP_HUGETLB 0x80000 /* create a huge page mapping */ > #define MAP_FIXED_NOREPLACE 0x100000 /* MAP_FIXED which doesn't unmap underlying mapping */ > -#ifdef CONFIG_MMAP_ALLOW_UNINITIALIZED > -# define MAP_UNINITIALIZED 0x4000000 /* For anonymous mmap, memory could be > +#define MAP_UNINITIALIZED 0x4000000 /* For anonymous mmap, memory could be > * uninitialized */ > -#else > -# define MAP_UNINITIALIZED 0x0 /* Don't support this flag */ > -#endif > > /* > * Flags for msync > diff --git a/include/uapi/asm-generic/mman-common.h b/include/uapi/asm-generic/mman-common.h > index abd238d0f7a4..cb556b430e71 100644 > --- a/include/uapi/asm-generic/mman-common.h > +++ b/include/uapi/asm-generic/mman-common.h > @@ -19,15 +19,13 @@ > #define MAP_TYPE 0x0f /* Mask for type of mapping */ > #define MAP_FIXED 0x10 /* Interpret addr exactly */ > #define MAP_ANONYMOUS 0x20 /* don't use a file */ > -#ifdef CONFIG_MMAP_ALLOW_UNINITIALIZED > -# define MAP_UNINITIALIZED 0x4000000 /* For anonymous mmap, memory could be uninitialized */ > -#else > -# define MAP_UNINITIALIZED 0x0 /* Don't support this flag */ > -#endif > > /* 0x0100 - 0x80000 flags are defined in asm-generic/mman.h */ > #define MAP_FIXED_NOREPLACE 0x100000 /* MAP_FIXED which doesn't unmap underlying mapping */ > > +#define MAP_UNINITIALIZED 0x4000000 /* For anonymous mmap, memory could be > + * uninitialized */ > + > /* > * Flags for mlock > */ > diff --git a/mm/nommu.c b/mm/nommu.c > index d8c02fbe03b5..ec75a0dffd4f 100644 > --- a/mm/nommu.c > +++ b/mm/nommu.c > @@ -1349,7 +1349,9 @@ unsigned long do_mmap(struct file *file, > add_nommu_region(region); > > /* clear anonymous mappings that don't ask for uninitialized data */ > - if (!vma->vm_file && !(flags & MAP_UNINITIALIZED)) > + if (!vma->vm_file && > + (!IS_ENABLED(CONFIG_MMAP_ALLOW_UNINITIALIZED) || > + !(flags & MAP_UNINITIALIZED))) > memset((void *)region->vm_start, 0, > region->vm_end - region->vm_start); > >