From patchwork Wed Apr 17 05:22:43 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexandre Ghiti X-Patchwork-Id: 10904541 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id BA1FD161F for ; Wed, 17 Apr 2019 05:30:44 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A298128915 for ; Wed, 17 Apr 2019 05:30:44 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 96CEF28A00; Wed, 17 Apr 2019 05:30:44 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED autolearn=unavailable version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id CEDEE2892E for ; Wed, 17 Apr 2019 05:30:42 +0000 (UTC) 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:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=wzNR0qKj4YasMlupOGmj61wakcWm8WSV/wAKuM3wVhM=; b=iO04GLBcR4JYGg 53043bnlF707aACwJU1HH7bco5KUvVvmWJtDAj0f6gjHNqoLr4WuOGXGz2IDpbOuksDoVv37AI/jO zP+wpXwK1DgAA6a38gvNlqbxQkpOyx4Bz0TgSX46iJTCbBO8PlYaIhu2lsPQtPgeF0m9imBVe7xEr RmlNGfzgZzkV85+FkOI51/CpRCH46PpBWvnv2wD/qVuNZ/ue4qQP7ivY1TeIFJUpjX1BCTMdC7iKq MLl32pLAd1dXP8mBJU2nZqSYsqqgO+JiXepzYXbl3joBk8Q7yo9lfB8GsUXQaWE8b6qw1v7vaBOyE yKTAOAiDV8/yR5LWX3Yw==; 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 1hGd9a-0005xf-Cy; Wed, 17 Apr 2019 05:30:38 +0000 Received: from relay12.mail.gandi.net ([217.70.178.232]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1hGd9X-0005xJ-4f; Wed, 17 Apr 2019 05:30:36 +0000 Received: from alex.numericable.fr (127.19.86.79.rev.sfr.net [79.86.19.127]) (Authenticated sender: alex@ghiti.fr) by relay12.mail.gandi.net (Postfix) with ESMTPSA id D715120000A; Wed, 17 Apr 2019 05:30:28 +0000 (UTC) From: Alexandre Ghiti To: Andrew Morton Subject: [PATCH v3 07/11] arm: Use generic mmap top-down layout Date: Wed, 17 Apr 2019 01:22:43 -0400 Message-Id: <20190417052247.17809-8-alex@ghiti.fr> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190417052247.17809-1-alex@ghiti.fr> References: <20190417052247.17809-1-alex@ghiti.fr> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190416_223035_482875_024F8D2C X-CRM114-Status: GOOD ( 13.85 ) 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: Albert Ou , Kees Cook , Alexandre Ghiti , Catalin Marinas , Palmer Dabbelt , Will Deacon , Russell King , Ralf Baechle , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Paul Burton , Alexander Viro , James Hogan , linux-fsdevel@vger.kernel.org, linux-riscv@lists.infradead.org, linux-mips@vger.kernel.org, Christoph Hellwig , linux-arm-kernel@lists.infradead.org, Luis Chamberlain Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP arm uses a top-down mmap layout by default that exactly fits the generic functions, so get rid of arch specific code and use the generic version by selecting ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT. Signed-off-by: Alexandre Ghiti Acked-by: Kees Cook --- arch/arm/Kconfig | 1 + arch/arm/include/asm/processor.h | 2 -- arch/arm/mm/mmap.c | 62 -------------------------------- 3 files changed, 1 insertion(+), 64 deletions(-) diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 850b4805e2d1..f8f603da181f 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -28,6 +28,7 @@ config ARM select ARCH_SUPPORTS_ATOMIC_RMW select ARCH_USE_BUILTIN_BSWAP select ARCH_USE_CMPXCHG_LOCKREF + select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU select ARCH_WANT_IPC_PARSE_VERSION select BUILDTIME_EXTABLE_SORT if MMU select CLONE_BACKWARDS diff --git a/arch/arm/include/asm/processor.h b/arch/arm/include/asm/processor.h index 57fe73ea0f72..944ef1fb1237 100644 --- a/arch/arm/include/asm/processor.h +++ b/arch/arm/include/asm/processor.h @@ -143,8 +143,6 @@ static inline void prefetchw(const void *ptr) #endif #endif -#define HAVE_ARCH_PICK_MMAP_LAYOUT - #endif #endif /* __ASM_ARM_PROCESSOR_H */ diff --git a/arch/arm/mm/mmap.c b/arch/arm/mm/mmap.c index 0b94b674aa91..b8d912ac9e61 100644 --- a/arch/arm/mm/mmap.c +++ b/arch/arm/mm/mmap.c @@ -17,43 +17,6 @@ ((((addr)+SHMLBA-1)&~(SHMLBA-1)) + \ (((pgoff)<> (PAGE_SHIFT - 12)) - -static int mmap_is_legacy(struct rlimit *rlim_stack) -{ - if (current->personality & ADDR_COMPAT_LAYOUT) - return 1; - - if (rlim_stack->rlim_cur == RLIM_INFINITY) - return 1; - - return sysctl_legacy_va_layout; -} - -static unsigned long mmap_base(unsigned long rnd, struct rlimit *rlim_stack) -{ - unsigned long gap = rlim_stack->rlim_cur; - unsigned long pad = stack_guard_gap; - - /* Account for stack randomization if necessary */ - if (current->flags & PF_RANDOMIZE) - pad += (STACK_RND_MASK << PAGE_SHIFT); - - /* Values close to RLIM_INFINITY can overflow. */ - if (gap + pad > gap) - gap += pad; - - if (gap < MIN_GAP) - gap = MIN_GAP; - else if (gap > MAX_GAP) - gap = MAX_GAP; - - return PAGE_ALIGN(STACK_TOP - gap - rnd); -} - /* * We need to ensure that shared mappings are correctly aligned to * avoid aliasing issues with VIPT caches. We need to ensure that @@ -181,31 +144,6 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0, return addr; } -unsigned long arch_mmap_rnd(void) -{ - unsigned long rnd; - - rnd = get_random_long() & ((1UL << mmap_rnd_bits) - 1); - - return rnd << PAGE_SHIFT; -} - -void arch_pick_mmap_layout(struct mm_struct *mm, struct rlimit *rlim_stack) -{ - unsigned long random_factor = 0UL; - - if (current->flags & PF_RANDOMIZE) - random_factor = arch_mmap_rnd(); - - if (mmap_is_legacy(rlim_stack)) { - mm->mmap_base = TASK_UNMAPPED_BASE + random_factor; - mm->get_unmapped_area = arch_get_unmapped_area; - } else { - mm->mmap_base = mmap_base(random_factor, rlim_stack); - mm->get_unmapped_area = arch_get_unmapped_area_topdown; - } -} - /* * You really shouldn't be using read() or write() on /dev/mem. This * might go away in the future.