Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751799AbdHBXTO (ORCPT ); Wed, 2 Aug 2017 19:19:14 -0400 Received: from mail-qt0-f181.google.com ([209.85.216.181]:38389 "EHLO mail-qt0-f181.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751161AbdHBXTN (ORCPT ); Wed, 2 Aug 2017 19:19:13 -0400 MIME-Version: 1.0 In-Reply-To: References: <20170802225159.159536-1-mka@chromium.org> <20170802225159.159536-2-mka@chromium.org> From: Nick Desaulniers Date: Wed, 2 Aug 2017 16:19:11 -0700 Message-ID: Subject: Re: [PATCH 2/2] arm64: Define PAGE_OFFSET using GENMASK_ULL To: Matthias Kaehlcke Cc: zijun_hu , Andrew Morton , Catalin Marinas , Will Deacon , Mark Rutland , Laura Abbott , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Doug Anderson , Greg Hackmann Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2668 Lines: 73 hmm, seems including the definition of GENMASK_ULL causes tons of issues see definition of UL() macro defines _AC token pastes UL on literal when not assembly so looks like GENMASK_ULL is not ready to be used from assembly On Wed, Aug 2, 2017 at 4:13 PM, Nick Desaulniers wrote: > don't forget to include linux/bitops.h now in memory.h > > /usr/local/google/home/ndesaulniers/android/kernel-wahoo/private/msm-google/arch/arm64/kernel/head.S:47:8: > error: > function-like macro 'GENMASK_ULL' is not defined > #elif (PAGE_OFFSET & 0x1fffff) != 0 > ^ > /usr/local/google/home/ndesaulniers/android/kernel-wahoo/private/msm-google/arch/arm64/include/asm/memory.h:52:22: > note: > > expanded from macro 'PAGE_OFFSET' > #define PAGE_OFFSET GENMASK_ULL(BITS_PER_LONG_LONG - 1, VA_BITS - 1) > ^ > 1 error generated. > > On Wed, Aug 2, 2017 at 3:51 PM, Matthias Kaehlcke wrote: >> As is the definition causes an integer overflow, which is expected, >> however clang raises the following warning: >> >> arch/arm64/kernel/head.S:47:8: warning: >> integer overflow in preprocessor expression >> #elif (PAGE_OFFSET & 0x1fffff) != 0 >> ^~~~~~~~~~~ >> arch/arm64/include/asm/memory.h:52:46: note: >> expanded from macro 'PAGE_OFFSET' >> #define PAGE_OFFSET (UL(0xffffffffffffffff) << (VA_BITS - 1)) >> ~~~~~~~~~~~~~~~~~~ ^ ~~~~~~~~~~~~~ >> >> Use GENMASK_ULL() instead of shifting explicitly, the macro takes care >> of avoiding the overflow. >> >> Reported-by: Nick Desaulniers >> Signed-off-by: Matthias Kaehlcke >> --- >> arch/arm64/include/asm/memory.h | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h >> index 32f82723338a..732d4eed8edd 100644 >> --- a/arch/arm64/include/asm/memory.h >> +++ b/arch/arm64/include/asm/memory.h >> @@ -65,7 +65,7 @@ >> */ >> #define VA_BITS (CONFIG_ARM64_VA_BITS) >> #define VA_START (UL(0xffffffffffffffff) << VA_BITS) >> -#define PAGE_OFFSET (UL(0xffffffffffffffff) << (VA_BITS - 1)) >> +#define PAGE_OFFSET GENMASK_ULL(BITS_PER_LONG_LONG - 1, VA_BITS - 1) >> #define KIMAGE_VADDR (MODULES_END) >> #define MODULES_END (MODULES_VADDR + MODULES_VSIZE) >> #define MODULES_VADDR (VA_START + KASAN_SHADOW_SIZE) >> -- >> 2.14.0.rc1.383.gd1ce394fe2-goog >> > > > > -- > Thanks, > ~Nick Desaulniers -- Thanks, ~Nick Desaulniers