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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 59EDEC433EF for ; Thu, 4 Nov 2021 17:01:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3A1FD611EE for ; Thu, 4 Nov 2021 17:01:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232167AbhKDREJ (ORCPT ); Thu, 4 Nov 2021 13:04:09 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50350 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231944AbhKDRDq (ORCPT ); Thu, 4 Nov 2021 13:03:46 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BC9ABC06120B for ; Thu, 4 Nov 2021 10:01:07 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Content-Type:MIME-Version:References: Subject:Cc:To:From:Date:Message-ID:Sender:Reply-To:Content-Transfer-Encoding: Content-ID:Content-Description:In-Reply-To; bh=5EidmflN1FISKMVzA9sUXSQxCA5c9nKoVVrPLxsEVqM=; b=OFNoPIaXSAHbqFqvRgXeX749vt uk62WmK8WjOS8C3xCMjW/0ScKv+lyGwwuhi2+5ZjwPlVG/hfvrGxjMJq4ddJ0t5UxFQ5fKXLv+/qW 7TDHExCUAhaqOukQpEA5PriM8OSJtwPHgWQmD9ihmq5GfvD0UXF6VqUesT4HG9TVrSuGk/aqh+pip 6GrYu5FPg0NOlSdVHHbOHW5EBn7lMzAVVE+/Nd/br+Sg6dcCErxM39YnvF9nnievjtuyYqT7KxW+G jgLTlcuLlhsHAOH+qiiuxndX602mKkhLaFV0mDpxUz9Y7Baj9fs/7LlkZpo2DG9fz5sDk28kOFO3w WMUI7mug==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1mig2Y-0060Fu-Hw; Thu, 04 Nov 2021 16:57:11 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 65B9430221D; Thu, 4 Nov 2021 17:56:35 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 0) id 514EC2DD49FB6; Thu, 4 Nov 2021 17:56:35 +0100 (CET) Message-ID: <20211104165525.527997216@infradead.org> User-Agent: quilt/0.66 Date: Thu, 04 Nov 2021 17:47:46 +0100 From: Peter Zijlstra To: x86@kernel.org Cc: linux-kernel@vger.kernel.org, peterz@infradead.org, jpoimboe@redhat.com, mark.rutland@arm.com, dvyukov@google.com, seanjc@google.com, pbonzini@redhat.com, mbenes@suse.cz Subject: [RFC][PATCH 17/22] x86,sgx: Remove .fixup usage References: <20211104164729.226550532@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Create EX_TYPE_FAULT_SGX which does as EX_TYPE_FAULT does, except adds this extra bit that SGX really fanies having. Signed-off-by: Peter Zijlstra (Intel) --- arch/x86/include/asm/extable_fixup_types.h | 2 + arch/x86/include/asm/sgx.h | 18 ++++++++++++++ arch/x86/kernel/cpu/sgx/encls.h | 36 ++++------------------------- arch/x86/mm/extable.c | 10 ++++++++ 4 files changed, 35 insertions(+), 31 deletions(-) --- a/arch/x86/include/asm/extable_fixup_types.h +++ b/arch/x86/include/asm/extable_fixup_types.h @@ -39,4 +39,6 @@ #define EX_TYPE_ZERO_REG (EX_TYPE_IMM_REG | EX_TYPE_IMM(0)) #define EX_TYPE_ONE_REG (EX_TYPE_IMM_REG | EX_TYPE_IMM(1)) +#define EX_TYPE_FAULT_SGX 18 + #endif --- a/arch/x86/include/asm/sgx.h +++ b/arch/x86/include/asm/sgx.h @@ -46,6 +46,24 @@ enum sgx_encls_function { }; /** + * SGX_ENCLS_FAULT_FLAG - flag signifying an ENCLS return code is a trapnr + * + * ENCLS has its own (positive value) error codes and also generates + * ENCLS specific #GP and #PF faults. And the ENCLS values get munged + * with system error codes as everything percolates back up the stack. + * Unfortunately (for us), we need to precisely identify each unique + * error code, e.g. the action taken if EWB fails varies based on the + * type of fault and on the exact SGX error code, i.e. we can't simply + * convert all faults to -EFAULT. + * + * To make all three error types coexist, we set bit 30 to identify an + * ENCLS fault. Bit 31 (technically bits N:31) is used to differentiate + * between positive (faults and SGX error codes) and negative (system + * error codes) values. + */ +#define SGX_ENCLS_FAULT_FLAG 0x40000000 + +/** * enum sgx_return_code - The return code type for ENCLS, ENCLU and ENCLV * %SGX_NOT_TRACKED: Previous ETRACK's shootdown sequence has not * been completed yet. --- a/arch/x86/kernel/cpu/sgx/encls.h +++ b/arch/x86/kernel/cpu/sgx/encls.h @@ -11,26 +11,8 @@ #include #include "sgx.h" -/** - * ENCLS_FAULT_FLAG - flag signifying an ENCLS return code is a trapnr - * - * ENCLS has its own (positive value) error codes and also generates - * ENCLS specific #GP and #PF faults. And the ENCLS values get munged - * with system error codes as everything percolates back up the stack. - * Unfortunately (for us), we need to precisely identify each unique - * error code, e.g. the action taken if EWB fails varies based on the - * type of fault and on the exact SGX error code, i.e. we can't simply - * convert all faults to -EFAULT. - * - * To make all three error types coexist, we set bit 30 to identify an - * ENCLS fault. Bit 31 (technically bits N:31) is used to differentiate - * between positive (faults and SGX error codes) and negative (system - * error codes) values. - */ -#define ENCLS_FAULT_FLAG 0x40000000 - /* Retrieve the encoded trapnr from the specified return code. */ -#define ENCLS_TRAPNR(r) ((r) & ~ENCLS_FAULT_FLAG) +#define ENCLS_TRAPNR(r) ((r) & ~SGX_ENCLS_FAULT_FLAG) /* Issue a WARN() about an ENCLS function. */ #define ENCLS_WARN(r, name) { \ @@ -50,7 +32,7 @@ */ static inline bool encls_faulted(int ret) { - return ret & ENCLS_FAULT_FLAG; + return ret & SGX_ENCLS_FAULT_FLAG; } /** @@ -88,11 +70,7 @@ static inline bool encls_failed(int ret) asm volatile( \ "1: .byte 0x0f, 0x01, 0xcf;\n\t" \ "2:\n" \ - ".section .fixup,\"ax\"\n" \ - "3: orl $"__stringify(ENCLS_FAULT_FLAG)",%%eax\n" \ - " jmp 2b\n" \ - ".previous\n" \ - _ASM_EXTABLE_FAULT(1b, 3b) \ + _ASM_EXTABLE_TYPE(1b, 2b, EX_TYPE_FAULT_SGX) \ : "=a"(ret) \ : "a"(rax), inputs \ : "memory", "cc"); \ @@ -127,7 +105,7 @@ static inline bool encls_failed(int ret) * * Return: * 0 on success, - * trapnr with ENCLS_FAULT_FLAG set on fault + * trapnr with SGX_ENCLS_FAULT_FLAG set on fault */ #define __encls_N(rax, rbx_out, inputs...) \ ({ \ @@ -136,11 +114,7 @@ static inline bool encls_failed(int ret) "1: .byte 0x0f, 0x01, 0xcf;\n\t" \ " xor %%eax,%%eax;\n" \ "2:\n" \ - ".section .fixup,\"ax\"\n" \ - "3: orl $"__stringify(ENCLS_FAULT_FLAG)",%%eax\n" \ - " jmp 2b\n" \ - ".previous\n" \ - _ASM_EXTABLE_FAULT(1b, 3b) \ + _ASM_EXTABLE_TYPE(1b, 2b, EX_TYPE_FAULT_SGX) \ : "=a"(ret), "=b"(rbx_out) \ : "a"(rax), inputs \ : "memory"); \ --- a/arch/x86/mm/extable.c +++ b/arch/x86/mm/extable.c @@ -9,6 +9,7 @@ #include #include #include +#include static inline unsigned long *pt_regs_nr(struct pt_regs *regs, int nr) { @@ -146,6 +147,13 @@ static bool ex_handler_imm_reg(const str return ex_handler_default(fixup, regs); } +static bool ex_handler_sgx(const struct exception_table_entry *fixup, + struct pt_regs *regs, int trapnr) +{ + regs->ax = trapnr | SGX_ENCLS_FAULT_FLAG; + return ex_handler_default(fixup, regs); +} + #define EX_TYPE_MASK 0x000000FF #define EX_REG_MASK 0x00000F00 #define EX_FLAG_MASK 0x0000F000 @@ -221,6 +229,8 @@ int fixup_exception(struct pt_regs *regs return ex_handler_pop_seg(e, regs); case EX_TYPE_IMM_REG: return ex_handler_imm_reg(e, regs, reg, imm); + case EX_TYPE_FAULT_SGX: + return ex_handler_sgx(e, regs, trapnr); } BUG(); }