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=-9.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 408ACC5CFFE for ; Tue, 11 Dec 2018 15:44:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 057B620855 for ; Tue, 11 Dec 2018 15:44:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1544543042; bh=EQhQ/jz9GSiri87p6mOhVl8XyyJr/v8PTvooQVHCRyQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=rqB84I4jfGLLlL5TOfEu+U/BN3tMrtMC9IKKgAJvDE/zx9I63i8bBxRCA4qSPe+Ht EHI/lL4UPMchCFgDMU7E2PGEqc+b5ErK3Pd5zC18g0hreTl3K3uVyQEGV+R4PpJ5qc HI7UCngGVqo7J8MGiwVJqQiW1I59uvaUFM+fOsHs= DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 057B620855 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727700AbeLKPoA (ORCPT ); Tue, 11 Dec 2018 10:44:00 -0500 Received: from mail.kernel.org ([198.145.29.99]:60458 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727659AbeLKPnx (ORCPT ); Tue, 11 Dec 2018 10:43:53 -0500 Received: from localhost (5356596B.cm-6-7b.dynamic.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id AA8A520672; Tue, 11 Dec 2018 15:43:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1544543033; bh=EQhQ/jz9GSiri87p6mOhVl8XyyJr/v8PTvooQVHCRyQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=CuP5PurrpA2NBed5Zp6kmh/PtKZuTHjRJH1/UlxlBV31ox7dzL9UGBTChXODGd7o9 668VwvWcF3PcO+K0JxD9pZAteAqn6I55ox/jVWcwY1F3vuBoRUGyArirvp5CC/prY8 aIpgx6nHqgfsTgts64NHDhmv6KvWemTqyPa+Cbaw= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Anton Blanchard , Michael Ellerman , Sasha Levin Subject: [PATCH 3.18 40/54] powerpc/vdso64: Use double word compare on pointers Date: Tue, 11 Dec 2018 16:41:28 +0100 Message-Id: <20181211151548.329260078@linuxfoundation.org> X-Mailer: git-send-email 2.20.0 In-Reply-To: <20181211151546.010073210@linuxfoundation.org> References: <20181211151546.010073210@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.18-stable review patch. If anyone has any objections, please let me know. ------------------ [ Upstream commit 5045ea37377ce8cca6890d32b127ad6770e6dce5 ] __kernel_get_syscall_map() and __kernel_clock_getres() use cmpli to check if the passed in pointer is non zero. cmpli maps to a 32 bit compare on binutils, so we ignore the top 32 bits. A simple test case can be created by passing in a bogus pointer with the bottom 32 bits clear. Using a clk_id that is handled by the VDSO, then one that is handled by the kernel shows the problem: printf("%d\n", clock_getres(CLOCK_REALTIME, (void *)0x100000000)); printf("%d\n", clock_getres(CLOCK_BOOTTIME, (void *)0x100000000)); And we get: 0 -1 The bigger issue is if we pass a valid pointer with the bottom 32 bits clear, in this case we will return success but won't write any data to the pointer. I stumbled across this issue because the LLVM integrated assembler doesn't accept cmpli with 3 arguments. Fix this by converting them to cmpldi. Fixes: a7f290dad32e ("[PATCH] powerpc: Merge vdso's and add vdso support to 32 bits kernel") Cc: stable@vger.kernel.org # v2.6.15+ Signed-off-by: Anton Blanchard Signed-off-by: Michael Ellerman Signed-off-by: Sasha Levin --- arch/powerpc/kernel/vdso64/datapage.S | 2 +- arch/powerpc/kernel/vdso64/gettimeofday.S | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/kernel/vdso64/datapage.S b/arch/powerpc/kernel/vdso64/datapage.S index 79796de11737..3263ee23170d 100644 --- a/arch/powerpc/kernel/vdso64/datapage.S +++ b/arch/powerpc/kernel/vdso64/datapage.S @@ -57,7 +57,7 @@ V_FUNCTION_BEGIN(__kernel_get_syscall_map) bl V_LOCAL_FUNC(__get_datapage) mtlr r12 addi r3,r3,CFG_SYSCALL_MAP64 - cmpli cr0,r4,0 + cmpldi cr0,r4,0 crclr cr0*4+so beqlr li r0,__NR_syscalls diff --git a/arch/powerpc/kernel/vdso64/gettimeofday.S b/arch/powerpc/kernel/vdso64/gettimeofday.S index a76b4af37ef2..382021324883 100644 --- a/arch/powerpc/kernel/vdso64/gettimeofday.S +++ b/arch/powerpc/kernel/vdso64/gettimeofday.S @@ -145,7 +145,7 @@ V_FUNCTION_BEGIN(__kernel_clock_getres) bne cr0,99f li r3,0 - cmpli cr0,r4,0 + cmpldi cr0,r4,0 crclr cr0*4+so beqlr lis r5,CLOCK_REALTIME_RES@h -- 2.19.1