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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3505DC433EF for ; Thu, 3 Feb 2022 18:12:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1353281AbiBCSMC (ORCPT ); Thu, 3 Feb 2022 13:12:02 -0500 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:39170 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232240AbiBCSL4 (ORCPT ); Thu, 3 Feb 2022 13:11:56 -0500 Received: from pps.filterd (m0098399.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.1.2/8.16.1.2) with SMTP id 213HXh1r003113; Thu, 3 Feb 2022 18:11:50 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-transfer-encoding; s=pp1; bh=HWB+U3RDOqKbXuykLxFCRkaOT1/jEZlEB+EBNvNUW88=; b=H3VWSaR21twmMz6USB0aemHO6qOYV5bsQ/Ye4i7jinpXvDMi89lBeLyUXE0fOgJlBDBU wudfquNF+4otm6ZaeBKPO2XZvZUttESFa/65pEFdX7hY6KO7bNHKPBLn4Aysa3sRL2TI gZur+a0yXdkhEJTwyKF5gg7EZZDtMzAo56KfbKs0+YJv2evu4wBqmwCN5zzKCDnjpTjA m0ql9oYgFlKho1cZTXiRq8zUV2tb6XK7HxT66Th1bpNSKoM2KoJ0fJMge8N9bp3m9iKR BI50xfz4zbI9tc1S/pyKdyVn7EWrTHSre7QKiqYGSI+XMeG5vcaMdJEhanILGoUYsBv9 8Q== Received: from ppma03fra.de.ibm.com (6b.4a.5195.ip4.static.sl-reverse.com [149.81.74.107]) by mx0a-001b2d01.pphosted.com with ESMTP id 3dyvcmx4md-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 03 Feb 2022 18:11:49 +0000 Received: from pps.filterd (ppma03fra.de.ibm.com [127.0.0.1]) by ppma03fra.de.ibm.com (8.16.1.2/8.16.1.2) with SMTP id 213I2jLS002657; Thu, 3 Feb 2022 18:11:47 GMT Received: from b06avi18626390.portsmouth.uk.ibm.com (b06avi18626390.portsmouth.uk.ibm.com [9.149.26.192]) by ppma03fra.de.ibm.com with ESMTP id 3dvw7a6u5e-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 03 Feb 2022 18:11:47 +0000 Received: from d06av21.portsmouth.uk.ibm.com (d06av21.portsmouth.uk.ibm.com [9.149.105.232]) by b06avi18626390.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 213I1oCb49283456 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 3 Feb 2022 18:01:50 GMT Received: from d06av21.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 10D7252050; Thu, 3 Feb 2022 18:11:44 +0000 (GMT) Received: from tuxmaker.boeblingen.de.ibm.com (unknown [9.152.85.9]) by d06av21.portsmouth.uk.ibm.com (Postfix) with ESMTP id BFCD15205F; Thu, 3 Feb 2022 18:11:43 +0000 (GMT) From: Janis Schoetterl-Glausch To: scgl@linux.ibm.com Cc: akpm@linux-foundation.org, arnd@arndb.de, borntraeger@linux.ibm.com, hca@linux.ibm.com, keescook@chromium.org, linux-kernel@vger.kernel.org, viro@zeniv.linux.org.uk Subject: [RFC PATCH 2/2] s390/uaccess: Provide raw_copy_from/to_user_opaque Date: Thu, 3 Feb 2022 19:11:41 +0100 Message-Id: <20220203181141.2682997-3-scgl@linux.ibm.com> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20220203181141.2682997-1-scgl@linux.ibm.com> References: <20220126173358.2951879-1-scgl@linux.ibm.com> <20220203181141.2682997-1-scgl@linux.ibm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 X-Proofpoint-GUID: jQp_CpsAu1cDYiYSu5_7N7y_xf8TKo5F X-Proofpoint-ORIG-GUID: jQp_CpsAu1cDYiYSu5_7N7y_xf8TKo5F X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.816,Hydra:6.0.425,FMLib:17.11.62.513 definitions=2022-02-03_06,2022-02-03_01,2021-12-02_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 mlxscore=0 priorityscore=1501 impostorscore=0 suspectscore=0 lowpriorityscore=0 malwarescore=0 adultscore=0 clxscore=1015 phishscore=0 mlxlogscore=939 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2201110000 definitions=main-2202030110 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This enables KVM to perform key checked guest accesses by passing the access key via the opaque argument of __copy_from/to_user_opaque. Since the existing uaccess implementation on s390 makes use of move instructions that support having an additional access key supplied, we can implement raw_copy_from/to_user_opaque by enhancing the existing implementation. Signed-off-by: Janis Schoetterl-Glausch --- arch/s390/include/asm/uaccess.h | 27 ++++++++++++++-- arch/s390/lib/uaccess.c | 56 ++++++++++++++++++++------------- 2 files changed, 60 insertions(+), 23 deletions(-) diff --git a/arch/s390/include/asm/uaccess.h b/arch/s390/include/asm/uaccess.h index 02b467461163..1a324bc3ae0b 100644 --- a/arch/s390/include/asm/uaccess.h +++ b/arch/s390/include/asm/uaccess.h @@ -33,11 +33,34 @@ static inline int __range_ok(unsigned long addr, unsigned long size) #define access_ok(addr, size) __access_ok(addr, size) +#define uaccess_opaque uaccess_opaque +struct uaccess_opaque { + u8 key; +}; + unsigned long __must_check -raw_copy_from_user(void *to, const void __user *from, unsigned long n); +raw_copy_from_user_opaque(void *to, const void __user *from, unsigned long n, + struct uaccess_opaque opaque); unsigned long __must_check -raw_copy_to_user(void __user *to, const void *from, unsigned long n); +raw_copy_to_user_opaque(void __user *to, const void *from, unsigned long n, + struct uaccess_opaque opaque); + +static __always_inline unsigned long __must_check +raw_copy_from_user(void *to, const void __user *from, unsigned long n) +{ + struct uaccess_opaque opaque = { .key = 0}; + + return raw_copy_from_user_opaque(to, from, n, opaque); +} + +static __always_inline unsigned long __must_check +raw_copy_to_user(void __user *to, const void *from, unsigned long n) +{ + struct uaccess_opaque opaque = { .key = 0}; + + return raw_copy_to_user_opaque(to, from, n, opaque); +} #ifndef CONFIG_KASAN #define INLINE_COPY_FROM_USER diff --git a/arch/s390/lib/uaccess.c b/arch/s390/lib/uaccess.c index d3a700385875..6446634c3b75 100644 --- a/arch/s390/lib/uaccess.c +++ b/arch/s390/lib/uaccess.c @@ -59,11 +59,13 @@ static inline int copy_with_mvcos(void) #endif static inline unsigned long copy_from_user_mvcos(void *x, const void __user *ptr, - unsigned long size) + unsigned long size, u8 key) { unsigned long tmp1, tmp2; union oac spec = { + .oac2.key = key, .oac2.as = PSW_BITS_AS_SECONDARY, + .oac2.k = 1, .oac2.a = 1, }; @@ -94,19 +96,19 @@ static inline unsigned long copy_from_user_mvcos(void *x, const void __user *ptr } static inline unsigned long copy_from_user_mvcp(void *x, const void __user *ptr, - unsigned long size) + unsigned long size, u8 key) { unsigned long tmp1, tmp2; tmp1 = -256UL; asm volatile( " sacf 0\n" - "0: mvcp 0(%0,%2),0(%1),%3\n" + "0: mvcp 0(%0,%2),0(%1),%[key]\n" "7: jz 5f\n" "1: algr %0,%3\n" " la %1,256(%1)\n" " la %2,256(%2)\n" - "2: mvcp 0(%0,%2),0(%1),%3\n" + "2: mvcp 0(%0,%2),0(%1),%[key]\n" "8: jnz 1b\n" " j 5f\n" "3: la %4,255(%1)\n" /* %4 = ptr + 255 */ @@ -115,7 +117,7 @@ static inline unsigned long copy_from_user_mvcp(void *x, const void __user *ptr, " slgr %4,%1\n" " clgr %0,%4\n" /* copy crosses next page boundary? */ " jnh 6f\n" - "4: mvcp 0(%4,%2),0(%1),%3\n" + "4: mvcp 0(%4,%2),0(%1),%[key]\n" "9: slgr %0,%4\n" " j 6f\n" "5: slgr %0,%0\n" @@ -123,24 +125,31 @@ static inline unsigned long copy_from_user_mvcp(void *x, const void __user *ptr, EX_TABLE(0b,3b) EX_TABLE(2b,3b) EX_TABLE(4b,6b) EX_TABLE(7b,3b) EX_TABLE(8b,3b) EX_TABLE(9b,6b) : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2) - : : "cc", "memory"); + : [key] "d" (key << 4) + : "cc", "memory"); return size; } -unsigned long raw_copy_from_user(void *to, const void __user *from, unsigned long n) +unsigned long raw_copy_from_user_opaque(void *to, const void __user *from, + unsigned long n, + struct uaccess_opaque opaque) { + u8 key = opaque.key; + if (copy_with_mvcos()) - return copy_from_user_mvcos(to, from, n); - return copy_from_user_mvcp(to, from, n); + return copy_from_user_mvcos(to, from, n, key); + return copy_from_user_mvcp(to, from, n, key); } -EXPORT_SYMBOL(raw_copy_from_user); +EXPORT_SYMBOL(raw_copy_from_user_opaque); -static inline unsigned long copy_to_user_mvcos(void __user *ptr, const void *x, - unsigned long size) +inline unsigned long copy_to_user_mvcos(void __user *ptr, const void *x, + unsigned long size, u8 key) { unsigned long tmp1, tmp2; union oac spec = { + .oac1.key = key, .oac1.as = PSW_BITS_AS_SECONDARY, + .oac1.k = 1, .oac1.a = 1, }; @@ -171,19 +180,19 @@ static inline unsigned long copy_to_user_mvcos(void __user *ptr, const void *x, } static inline unsigned long copy_to_user_mvcs(void __user *ptr, const void *x, - unsigned long size) + unsigned long size, u8 key) { unsigned long tmp1, tmp2; tmp1 = -256UL; asm volatile( " sacf 0\n" - "0: mvcs 0(%0,%1),0(%2),%3\n" + "0: mvcs 0(%0,%1),0(%2),%[key]\n" "7: jz 5f\n" "1: algr %0,%3\n" " la %1,256(%1)\n" " la %2,256(%2)\n" - "2: mvcs 0(%0,%1),0(%2),%3\n" + "2: mvcs 0(%0,%1),0(%2),%[key]\n" "8: jnz 1b\n" " j 5f\n" "3: la %4,255(%1)\n" /* %4 = ptr + 255 */ @@ -192,7 +201,7 @@ static inline unsigned long copy_to_user_mvcs(void __user *ptr, const void *x, " slgr %4,%1\n" " clgr %0,%4\n" /* copy crosses next page boundary? */ " jnh 6f\n" - "4: mvcs 0(%4,%1),0(%2),%3\n" + "4: mvcs 0(%4,%1),0(%2),%[key]\n" "9: slgr %0,%4\n" " j 6f\n" "5: slgr %0,%0\n" @@ -200,17 +209,22 @@ static inline unsigned long copy_to_user_mvcs(void __user *ptr, const void *x, EX_TABLE(0b,3b) EX_TABLE(2b,3b) EX_TABLE(4b,6b) EX_TABLE(7b,3b) EX_TABLE(8b,3b) EX_TABLE(9b,6b) : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2) - : : "cc", "memory"); + : [key] "d" (key << 4) + : "cc", "memory"); return size; } -unsigned long raw_copy_to_user(void __user *to, const void *from, unsigned long n) +unsigned long raw_copy_to_user_opaque(void __user *to, const void *from, + unsigned long n, + struct uaccess_opaque opaque) { + u8 key = opaque.key; + if (copy_with_mvcos()) - return copy_to_user_mvcos(to, from, n); - return copy_to_user_mvcs(to, from, n); + return copy_to_user_mvcos(to, from, n, key); + return copy_to_user_mvcs(to, from, n, key); } -EXPORT_SYMBOL(raw_copy_to_user); +EXPORT_SYMBOL(raw_copy_to_user_opaque); static inline unsigned long clear_user_mvcos(void __user *to, unsigned long size) { -- 2.32.0