From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752261AbdKHLHO (ORCPT ); Wed, 8 Nov 2017 06:07:14 -0500 Received: from terminus.zytor.com ([65.50.211.136]:51981 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752232AbdKHLHL (ORCPT ); Wed, 8 Nov 2017 06:07:11 -0500 Date: Wed, 8 Nov 2017 02:59:03 -0800 From: tip-bot for Ricardo Neri Message-ID: Cc: adam.buchbinder@gmail.com, dvyukov@google.com, tony.luck@intel.com, pbonzini@redhat.com, peterz@infradead.org, hpa@zytor.com, keescook@chromium.org, ray.huang@amd.com, mhiramat@kernel.org, jpoimboe@redhat.com, linux-kernel@vger.kernel.org, dvlasenk@redhat.com, shuah@kernel.org, cmetcalf@mellanox.com, bp@alien8.de, qiaowei.ren@intel.com, colin.king@canonical.com, slaoub@gmail.com, tglx@linutronix.de, corbet@lwn.net, acme@redhat.com, jslaby@suse.cz, ravi.v.shankar@intel.com, mingo@kernel.org, ricardo.neri-calderon@linux.intel.com, lstoakes@gmail.com, luto@kernel.org, brgerst@gmail.com, akpm@linux-foundation.org, dave.hansen@linux.intel.com, torvalds@linux-foundation.org, thgarnie@google.com, vbabka@suse.cz, mst@redhat.com, adrian.hunter@intel.com, paul.gortmaker@windriver.com, bp@suse.de Reply-To: dave.hansen@linux.intel.com, torvalds@linux-foundation.org, adrian.hunter@intel.com, bp@suse.de, paul.gortmaker@windriver.com, thgarnie@google.com, vbabka@suse.cz, mst@redhat.com, ravi.v.shankar@intel.com, ricardo.neri-calderon@linux.intel.com, lstoakes@gmail.com, mingo@kernel.org, jslaby@suse.cz, akpm@linux-foundation.org, brgerst@gmail.com, luto@kernel.org, qiaowei.ren@intel.com, bp@alien8.de, slaoub@gmail.com, colin.king@canonical.com, dvlasenk@redhat.com, jpoimboe@redhat.com, linux-kernel@vger.kernel.org, cmetcalf@mellanox.com, shuah@kernel.org, corbet@lwn.net, acme@redhat.com, tglx@linutronix.de, pbonzini@redhat.com, tony.luck@intel.com, dvyukov@google.com, adam.buchbinder@gmail.com, keescook@chromium.org, hpa@zytor.com, mhiramat@kernel.org, ray.huang@amd.com, peterz@infradead.org In-Reply-To: <1509935277-22138-5-git-send-email-ricardo.neri-calderon@linux.intel.com> References: <1509935277-22138-5-git-send-email-ricardo.neri-calderon@linux.intel.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:x86/asm] x86/insn-eval: Handle 32-bit address encodings in virtual-8086 mode Git-Commit-ID: 86cc35109029b7f1b195cef6c74654bad95e81af X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 86cc35109029b7f1b195cef6c74654bad95e81af Gitweb: https://git.kernel.org/tip/86cc35109029b7f1b195cef6c74654bad95e81af Author: Ricardo Neri AuthorDate: Sun, 5 Nov 2017 18:27:49 -0800 Committer: Ingo Molnar CommitDate: Wed, 8 Nov 2017 11:16:20 +0100 x86/insn-eval: Handle 32-bit address encodings in virtual-8086 mode It is possible to utilize 32-bit address encodings in virtual-8086 mode via an address override instruction prefix. However, the range of the effective address is still limited to [0x-0xffff]. In such a case, return error. Also, linear addresses in virtual-8086 mode are limited to 20 bits. Enforce such limit by truncating the most significant bytes of the computed linear address. Signed-off-by: Ricardo Neri Reviewed-by: Thomas Gleixner Cc: Adam Buchbinder Cc: Adrian Hunter Cc: Andrew Morton Cc: Andy Lutomirski Cc: Arnaldo Carvalho de Melo Cc: Borislav Petkov Cc: Borislav Petkov Cc: Brian Gerst Cc: Chen Yucong Cc: Chris Metcalf Cc: Colin Ian King Cc: Dave Hansen Cc: Denys Vlasenko Cc: Dmitry Vyukov Cc: H. Peter Anvin Cc: Huang Rui Cc: Jiri Slaby Cc: Jonathan Corbet Cc: Josh Poimboeuf Cc: Kees Cook Cc: Linus Torvalds Cc: Lorenzo Stoakes Cc: Masami Hiramatsu Cc: Michael S. Tsirkin Cc: Paolo Bonzini Cc: Paul Gortmaker Cc: Peter Zijlstra Cc: Qiaowei Ren Cc: Ravi V. Shankar Cc: Shuah Khan Cc: Thomas Garnier Cc: Tony Luck Cc: Vlastimil Babka Cc: ricardo.neri@intel.com Link: http://lkml.kernel.org/r/1509935277-22138-5-git-send-email-ricardo.neri-calderon@linux.intel.com Signed-off-by: Ingo Molnar --- arch/x86/lib/insn-eval.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/arch/x86/lib/insn-eval.c b/arch/x86/lib/insn-eval.c index 1ac3973..ef102db 100644 --- a/arch/x86/lib/insn-eval.c +++ b/arch/x86/lib/insn-eval.c @@ -1042,12 +1042,23 @@ static void __user *get_addr_ref_32(struct insn *insn, struct pt_regs *regs) goto out; /* + * Even though 32-bit address encodings are allowed in virtual-8086 + * mode, the address range is still limited to [0x-0xffff]. + */ + if (v8086_mode(regs) && (eff_addr & ~0xffff)) + goto out; + + /* * Data type long could be 64 bits in size. Ensure that our 32-bit * effective address is not sign-extended when computing the linear * address. */ linear_addr = (unsigned long)(eff_addr & 0xffffffff) + seg_base; + /* Limit linear address to 20 bits */ + if (v8086_mode(regs)) + linear_addr &= 0xfffff; + out: return (void __user *)linear_addr; }