From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f197.google.com (mail-pf0-f197.google.com [209.85.192.197]) by kanga.kvack.org (Postfix) with ESMTP id E90F76B007E for ; Fri, 27 May 2016 08:38:27 -0400 (EDT) Received: by mail-pf0-f197.google.com with SMTP id c84so91101152pfc.3 for ; Fri, 27 May 2016 05:38:27 -0700 (PDT) Received: from foss.arm.com (foss.arm.com. [217.140.101.70]) by mx.google.com with ESMTP id r74si14198028pfb.45.2016.05.27.05.38.26 for ; Fri, 27 May 2016 05:38:26 -0700 (PDT) Date: Fri, 27 May 2016 13:38:10 +0100 From: Mark Rutland Subject: Re: [PATCH] arm64: kasan: instrument user memory access API Message-ID: <20160527123809.GD24469@leverpostej> References: <1464288231-11304-1-git-send-email-yang.shi@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1464288231-11304-1-git-send-email-yang.shi@linaro.org> Sender: owner-linux-mm@kvack.org List-ID: To: Yang Shi Cc: aryabinin@virtuozzo.com, will.deacon@arm.com, catalin.marinas@arm.com, linux-mm@kvack.org, linaro-kernel@lists.linaro.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Hi, On Thu, May 26, 2016 at 11:43:51AM -0700, Yang Shi wrote: > The upstream commit 1771c6e1a567ea0ba2cccc0a4ffe68a1419fd8ef > ("x86/kasan: instrument user memory access API") added KASAN instrument to > x86 user memory access API, so added such instrument to ARM64 too. > > Tested by test_kasan module. I just gave this a go atop of the current HEAD (dc03c0f9d12d8528) on a Juno R1 board. I hit the expected exceptions when using the test_kasan module (once I remembered to rebuild it), and things seem to run smoothly otherwise. I don't see any built issues when !CONFIG_KASAN, and the patch itself looks right to me. So FWIW: Acked-by: Mark Rutland Tested-by: Mark Rutland As an aside, it's a shame that each architecture has to duplicate this logic, rather than having something in the generic code like: static inline unsigned long __must_check copy_from_user(void *to, const void __user *from, unsigned long n) { kasan_check_read(from, n); arch_copy_from_user(to, from, n); } Thanks, Mark. > > Signed-off-by: Yang Shi > --- > arch/arm64/include/asm/uaccess.h | 18 ++++++++++++++++-- > 1 file changed, 16 insertions(+), 2 deletions(-) > > diff --git a/arch/arm64/include/asm/uaccess.h b/arch/arm64/include/asm/uaccess.h > index 0685d74..ec352fa 100644 > --- a/arch/arm64/include/asm/uaccess.h > +++ b/arch/arm64/include/asm/uaccess.h > @@ -23,6 +23,7 @@ > */ > #include > #include > +#include > > #include > #include > @@ -276,6 +277,8 @@ extern unsigned long __must_check __clear_user(void __user *addr, unsigned long > > static inline unsigned long __must_check copy_from_user(void *to, const void __user *from, unsigned long n) > { > + kasan_check_write(to, n); > + > if (access_ok(VERIFY_READ, from, n)) > n = __copy_from_user(to, from, n); > else /* security hole - plug it */ > @@ -285,6 +288,8 @@ static inline unsigned long __must_check copy_from_user(void *to, const void __u > > static inline unsigned long __must_check copy_to_user(void __user *to, const void *from, unsigned long n) > { > + kasan_check_read(from, n); > + > if (access_ok(VERIFY_WRITE, to, n)) > n = __copy_to_user(to, from, n); > return n; > @@ -297,8 +302,17 @@ static inline unsigned long __must_check copy_in_user(void __user *to, const voi > return n; > } > > -#define __copy_to_user_inatomic __copy_to_user > -#define __copy_from_user_inatomic __copy_from_user > +static inline unsigned long __copy_to_user_inatomic(void __user *to, const void *from, unsigned long n) > +{ > + kasan_check_read(from, n); > + return __copy_to_user(to, from, n); > +} > + > +static inline unsigned long __copy_from_user_inatomic(void *to, const void __user *from, unsigned long n) > +{ > + kasan_check_write(to, n); > + return __copy_from_user(to, from, n); > +} > > static inline unsigned long __must_check clear_user(void __user *to, unsigned long n) > { > -- > 2.0.2 > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel > -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org