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=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 3A8B3C43331 for ; Fri, 3 Apr 2020 07:21:02 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id F2233206F8 for ; Fri, 3 Apr 2020 07:21:01 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=c-s.fr header.i=@c-s.fr header.b="SxWEnBj+" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F2233206F8 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=c-s.fr Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 65A098E000B; Fri, 3 Apr 2020 03:20:57 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 5DF7B8E000C; Fri, 3 Apr 2020 03:20:57 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 481D08E000B; Fri, 3 Apr 2020 03:20:57 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0125.hostedemail.com [216.40.44.125]) by kanga.kvack.org (Postfix) with ESMTP id 221818E000A for ; Fri, 3 Apr 2020 03:20:57 -0400 (EDT) Received: from smtpin06.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id D85B9181AEF15 for ; Fri, 3 Apr 2020 07:20:56 +0000 (UTC) X-FDA: 76665696912.06.pump79_426888cfc370e X-HE-Tag: pump79_426888cfc370e X-Filterd-Recvd-Size: 6611 Received: from pegase1.c-s.fr (pegase1.c-s.fr [93.17.236.30]) by imf07.hostedemail.com (Postfix) with ESMTP for ; Fri, 3 Apr 2020 07:20:56 +0000 (UTC) Received: from localhost (mailhub1-int [192.168.12.234]) by localhost (Postfix) with ESMTP id 48trv916Qhz9txk1; Fri, 3 Apr 2020 09:20:53 +0200 (CEST) Authentication-Results: localhost; dkim=pass reason="1024-bit key; insecure key" header.d=c-s.fr header.i=@c-s.fr header.b=SxWEnBj+; dkim-adsp=pass; dkim-atps=neutral X-Virus-Scanned: Debian amavisd-new at c-s.fr Received: from pegase1.c-s.fr ([192.168.12.234]) by localhost (pegase1.c-s.fr [192.168.12.234]) (amavisd-new, port 10024) with ESMTP id 0H3X2puqBSCu; Fri, 3 Apr 2020 09:20:53 +0200 (CEST) Received: from messagerie.si.c-s.fr (messagerie.si.c-s.fr [192.168.25.192]) by pegase1.c-s.fr (Postfix) with ESMTP id 48trv86VBKz9txk0; Fri, 3 Apr 2020 09:20:52 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=c-s.fr; s=mail; t=1585898452; bh=BJgBTHe+L99GMNpZ0oFafGfoiOecONCckWzwsc5wUUE=; h=In-Reply-To:References:From:Subject:To:Cc:Date:From; b=SxWEnBj+72o7ALWqfRfrPFTYJjaUdZfHDcAAkCRllmCJz4B5zYqxoBhW8jW0N0CNf J8x+DDW2r+/4kgtPToKdEKU4hQrT15GDPH6pApmdNUfXn6ILoJyxJ88eiyFlDV0vNt ZNVui8BprR8PAMIvUGlM5sgzxixpc0U8AN1c4KUk= Received: from localhost (localhost [127.0.0.1]) by messagerie.si.c-s.fr (Postfix) with ESMTP id BAF618B944; Fri, 3 Apr 2020 09:20:53 +0200 (CEST) X-Virus-Scanned: amavisd-new at c-s.fr Received: from messagerie.si.c-s.fr ([127.0.0.1]) by localhost (messagerie.si.c-s.fr [127.0.0.1]) (amavisd-new, port 10023) with ESMTP id vLoIaVhxCm-w; Fri, 3 Apr 2020 09:20:53 +0200 (CEST) Received: from pc16570vm.idsi0.si.c-s.fr (unknown [192.168.4.90]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 6F6568B75B; Fri, 3 Apr 2020 09:20:53 +0200 (CEST) Received: by pc16570vm.idsi0.si.c-s.fr (Postfix, from userid 0) id 4569E65700; Fri, 3 Apr 2020 07:20:53 +0000 (UTC) Message-Id: <6c83af0f0809ef2a955c39ac622767f6cbede035.1585898438.git.christophe.leroy@c-s.fr> In-Reply-To: <36e43241c7f043a24b5069e78c6a7edd11043be5.1585898438.git.christophe.leroy@c-s.fr> References: <36e43241c7f043a24b5069e78c6a7edd11043be5.1585898438.git.christophe.leroy@c-s.fr> From: Christophe Leroy Subject: [PATCH v2 4/5] powerpc/uaccess: Implement user_read_access_begin and user_write_access_begin To: Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , airlied@linux.ie, daniel@ffwll.ch, torvalds@linux-foundation.org, viro@zeniv.linux.org.uk, akpm@linux-foundation.org, keescook@chromium.org, hpa@zytor.com Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-mm@kvack.org, linux-arch@vger.kernel.org, intel-gfx@lists.freedesktop.org Date: Fri, 3 Apr 2020 07:20:53 +0000 (UTC) X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Add support for selective read or write user access with user_read_access_begin/end and user_write_access_begin/end. Signed-off-by: Christophe Leroy Reviewed-by: Kees Cook --- v2: no change --- arch/powerpc/include/asm/book3s/32/kup.h | 4 ++-- arch/powerpc/include/asm/kup.h | 14 +++++++++++++- arch/powerpc/include/asm/uaccess.h | 22 ++++++++++++++++++++++ 3 files changed, 37 insertions(+), 3 deletions(-) diff --git a/arch/powerpc/include/asm/book3s/32/kup.h b/arch/powerpc/include/asm/book3s/32/kup.h index 3c0ba22dc360..1617e73bee30 100644 --- a/arch/powerpc/include/asm/book3s/32/kup.h +++ b/arch/powerpc/include/asm/book3s/32/kup.h @@ -108,7 +108,7 @@ static __always_inline void allow_user_access(void __user *to, const void __user u32 addr, end; BUILD_BUG_ON(!__builtin_constant_p(dir)); - BUILD_BUG_ON(dir == KUAP_CURRENT); + BUILD_BUG_ON(dir & ~KUAP_READ_WRITE); if (!(dir & KUAP_WRITE)) return; @@ -131,7 +131,7 @@ static __always_inline void prevent_user_access(void __user *to, const void __us BUILD_BUG_ON(!__builtin_constant_p(dir)); - if (dir == KUAP_CURRENT) { + if (dir & KUAP_CURRENT_WRITE) { u32 kuap = current->thread.kuap; if (unlikely(!kuap)) diff --git a/arch/powerpc/include/asm/kup.h b/arch/powerpc/include/asm/kup.h index 92bcd1a26d73..c745ee41ad66 100644 --- a/arch/powerpc/include/asm/kup.h +++ b/arch/powerpc/include/asm/kup.h @@ -10,7 +10,9 @@ * Use the current saved situation instead of the to/from/size params. * Used on book3s/32 */ -#define KUAP_CURRENT 4 +#define KUAP_CURRENT_READ 4 +#define KUAP_CURRENT_WRITE 8 +#define KUAP_CURRENT (KUAP_CURRENT_READ | KUAP_CURRENT_WRITE) #ifdef CONFIG_PPC64 #include @@ -101,6 +103,16 @@ static inline void prevent_current_access_user(void) prevent_user_access(NULL, NULL, ~0UL, KUAP_CURRENT); } +static inline void prevent_current_read_from_user(void) +{ + prevent_user_access(NULL, NULL, ~0UL, KUAP_CURRENT_READ); +} + +static inline void prevent_current_write_to_user(void) +{ + prevent_user_access(NULL, NULL, ~0UL, KUAP_CURRENT_WRITE); +} + #endif /* !__ASSEMBLY__ */ #endif /* _ASM_POWERPC_KUAP_H_ */ diff --git a/arch/powerpc/include/asm/uaccess.h b/arch/powerpc/include/asm/uaccess.h index 2f500debae21..4427d419eb1d 100644 --- a/arch/powerpc/include/asm/uaccess.h +++ b/arch/powerpc/include/asm/uaccess.h @@ -468,6 +468,28 @@ static __must_check inline bool user_access_begin(const void __user *ptr, size_t #define user_access_save prevent_user_access_return #define user_access_restore restore_user_access +static __must_check inline bool +user_read_access_begin(const void __user *ptr, size_t len) +{ + if (unlikely(!access_ok(ptr, len))) + return false; + allow_read_from_user(ptr, len); + return true; +} +#define user_read_access_begin user_read_access_begin +#define user_read_access_end prevent_current_read_from_user + +static __must_check inline bool +user_write_access_begin(const void __user *ptr, size_t len) +{ + if (unlikely(!access_ok(ptr, len))) + return false; + allow_write_to_user((void __user *)ptr, len); + return true; +} +#define user_write_access_begin user_write_access_begin +#define user_write_access_end prevent_current_write_to_user + #define unsafe_op_wrap(op, err) do { if (unlikely(op)) goto err; } while (0) #define unsafe_get_user(x, p, e) unsafe_op_wrap(__get_user_allowed(x, p), e) #define unsafe_put_user(x, p, e) unsafe_op_wrap(__put_user_allowed(x, p), e) -- 2.25.0