From patchwork Tue Jul 10 22:26:18 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yu-cheng Yu X-Patchwork-Id: 10518149 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 74CB7600CA for ; Tue, 10 Jul 2018 22:31:27 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 66C7228F39 for ; Tue, 10 Jul 2018 22:31:27 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 59ED728F59; Tue, 10 Jul 2018 22:31:27 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.9 required=2.0 tests=BAYES_00, MAILING_LIST_MULTI, RCVD_IN_DNSWL_NONE autolearn=ham version=3.3.1 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B861228F39 for ; Tue, 10 Jul 2018 22:31:26 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 6C6F16B0008; Tue, 10 Jul 2018 18:31:14 -0400 (EDT) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id 44F3D6B0269; Tue, 10 Jul 2018 18:31:14 -0400 (EDT) X-Original-To: int-list-linux-mm@kvack.org X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 1961B6B000A; Tue, 10 Jul 2018 18:31:14 -0400 (EDT) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from mail-pl0-f71.google.com (mail-pl0-f71.google.com [209.85.160.71]) by kanga.kvack.org (Postfix) with ESMTP id 9CF176B000A for ; Tue, 10 Jul 2018 18:31:13 -0400 (EDT) Received: by mail-pl0-f71.google.com with SMTP id q18-v6so13399975pll.3 for ; Tue, 10 Jul 2018 15:31:13 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-original-authentication-results:x-gm-message-state:from:to:cc :subject:date:message-id:in-reply-to:references; bh=8246k6ojt/ooc1u8sSipcSsgGmyWpCQPo41VrF9gYLM=; b=MjNaroGoR+2xqIm/HpWenEi+cW7O0RzdMRc8hE5PuU4KKCnjzdgUfYfE7j6a27BiuF 2yhKgp6XEKVIvlPD8OHDQRHUck9PExXT95hqIY3/tbLtSo1l1rpQEi0R/KYXWR+O9krt GzEcYh+VxyLAdzCrHSu5StkByd1KR+KSY24JO3MqlAOMB5X5nJZjeDVU4DtBKuSoT0Hp 4oqOTCVvlgiJBrnECfkEvBHk4QRHfqISqPzhXpqAkhGH2PUjDF2Hvss44Op0rsltfK+b So/yiHP8+JmM4ID3+gtsq3GLV1Qpzg7XHt9NURU3Sdi9Gakh1zcMYtm24mJQaKgMRPNG TBMA== X-Original-Authentication-Results: mx.google.com; spf=pass (google.com: domain of yu-cheng.yu@intel.com designates 192.55.52.93 as permitted sender) smtp.mailfrom=yu-cheng.yu@intel.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=intel.com X-Gm-Message-State: APt69E2miTOJa8J71NYMdzOwz4izTuyAulGhbNJAmmNhWsxJePv9X58I qw0oKnm3Hpn9HiJGK6zpICht4rDd4M28UA14+wODUH7VVI4CnLEz37GulXLHs8+bD8YN4JKdaNM 0FopPHfkXuxIQyw6AATzNTFn6lGKRmsJId9+5j6xqAb1Z4ohd1oLMiu3d7IhExBF8Cg== X-Received: by 2002:a63:2043:: with SMTP id r3-v6mr24896881pgm.105.1531261873273; Tue, 10 Jul 2018 15:31:13 -0700 (PDT) X-Google-Smtp-Source: AAOMgpfPGixwL+3XenKcU3IFgb12zoSckZ7dqTMBFeskj5vq48MpfJRvV4HY50CVUF6k1qr8+Z2r X-Received: by 2002:a63:2043:: with SMTP id r3-v6mr24896824pgm.105.1531261872372; Tue, 10 Jul 2018 15:31:12 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1531261872; cv=none; d=google.com; s=arc-20160816; b=0j4bjfLsVVeQ1zRW2938VAQo+oAc/4AYbBk54qXcvR5m0IGNOLocLU5hn5BDijQPYl IsoGvBmnE6pgNIVFsZK/4PmFxKPkQsAahhHor+L0Zxj23LbK/qfQf51hmIXgOM+dtbhg 5fsHXqk8zhPUAxIjxgCNRiI16OvRQVKvKJoPvLHszrvSPeTES+FwIBSjkSEEx4vogZD8 pvnN+CUDuD9P2MLGyXNvh663wmt0+EGbiNuGf4NWq7GSqawlKcGrM8vDiOfR6qbWvXAN o9eLtkIS6JqPAQdVnHx57YuVLdO23UvCXGzs/jyWYGHSfryA0S/S8T4PUunOsmUU+2fr PkJw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=references:in-reply-to:message-id:date:subject:cc:to:from :arc-authentication-results; bh=8246k6ojt/ooc1u8sSipcSsgGmyWpCQPo41VrF9gYLM=; b=Jvz9SAbpez4m2rZ+78IWosGdjCX1Yx/s+T4y1kREO/skX9CsEBAQ1T+ao/hfvAwg6b GzPQG0RhPAJgIUvS5kRjn0sZP5zQ3nz65QocfbLLrscQ0L4neXWM2x3fuxBAi/AkDFCj CGFVweq7DDv/6mHo3PI/16IdnAoomrpiy12M0nJUozYbdra6fmN2+EfDly+doT53FUMY wwZQ+aQTJRD9eVCXPiAgGd1xDA3GPMZcJXlz6KOu34+1vThXzcUGQ/LOXJA9coIFuKcg xwZjqzObKiBXIzqeDJQ6KysFB0HHRyxBvSGVmxjmtIIxB1HtQ9Dw1MCkPVlYhWvq7CKk IS9g== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of yu-cheng.yu@intel.com designates 192.55.52.93 as permitted sender) smtp.mailfrom=yu-cheng.yu@intel.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=intel.com Received: from mga11.intel.com (mga11.intel.com. [192.55.52.93]) by mx.google.com with ESMTPS id q185-v6si17504162pga.322.2018.07.10.15.31.12 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 10 Jul 2018 15:31:12 -0700 (PDT) Received-SPF: pass (google.com: domain of yu-cheng.yu@intel.com designates 192.55.52.93 as permitted sender) client-ip=192.55.52.93; Authentication-Results: mx.google.com; spf=pass (google.com: domain of yu-cheng.yu@intel.com designates 192.55.52.93 as permitted sender) smtp.mailfrom=yu-cheng.yu@intel.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=intel.com X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by fmsmga102.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 10 Jul 2018 15:31:11 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.51,335,1526367600"; d="scan'208";a="70305381" Received: from 2b52.sc.intel.com ([143.183.136.52]) by fmsmga004.fm.intel.com with ESMTP; 10 Jul 2018 15:31:11 -0700 From: Yu-cheng Yu To: x86@kernel.org, "H. Peter Anvin" , Thomas Gleixner , Ingo Molnar , linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-mm@kvack.org, linux-arch@vger.kernel.org, linux-api@vger.kernel.org, Arnd Bergmann , Andy Lutomirski , Balbir Singh , Cyrill Gorcunov , Dave Hansen , Florian Weimer , "H.J. Lu" , Jann Horn , Jonathan Corbet , Kees Cook , Mike Kravetz , Nadav Amit , Oleg Nesterov , Pavel Machek , Peter Zijlstra , "Ravi V. Shankar" , Vedvyas Shanbhogue Cc: Yu-cheng Yu Subject: [RFC PATCH v2 06/27] x86/cet: Control protection exception handler Date: Tue, 10 Jul 2018 15:26:18 -0700 Message-Id: <20180710222639.8241-7-yu-cheng.yu@intel.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20180710222639.8241-1-yu-cheng.yu@intel.com> References: <20180710222639.8241-1-yu-cheng.yu@intel.com> 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: X-Virus-Scanned: ClamAV using ClamSMTP A control protection exception is triggered when a control flow transfer attempt violated shadow stack or indirect branch tracking constraints. For example, the return address for a RET instruction differs from the safe copy on the shadow stack; or a JMP instruction arrives at a non- ENDBR instruction. The control protection exception handler works in a similar way as the general protection fault handler. Signed-off-by: Yu-cheng Yu --- arch/x86/entry/entry_64.S | 2 +- arch/x86/include/asm/traps.h | 3 ++ arch/x86/kernel/idt.c | 4 +++ arch/x86/kernel/traps.c | 58 ++++++++++++++++++++++++++++++++++++ 4 files changed, 66 insertions(+), 1 deletion(-) diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S index 73a522d53b53..99398a27fe0b 100644 --- a/arch/x86/entry/entry_64.S +++ b/arch/x86/entry/entry_64.S @@ -999,7 +999,7 @@ idtentry spurious_interrupt_bug do_spurious_interrupt_bug has_error_code=0 idtentry coprocessor_error do_coprocessor_error has_error_code=0 idtentry alignment_check do_alignment_check has_error_code=1 idtentry simd_coprocessor_error do_simd_coprocessor_error has_error_code=0 - +idtentry control_protection do_control_protection has_error_code=1 /* * Reload gs selector with exception handling diff --git a/arch/x86/include/asm/traps.h b/arch/x86/include/asm/traps.h index 3de69330e6c5..5196050ff3d5 100644 --- a/arch/x86/include/asm/traps.h +++ b/arch/x86/include/asm/traps.h @@ -26,6 +26,7 @@ asmlinkage void invalid_TSS(void); asmlinkage void segment_not_present(void); asmlinkage void stack_segment(void); asmlinkage void general_protection(void); +asmlinkage void control_protection(void); asmlinkage void page_fault(void); asmlinkage void async_page_fault(void); asmlinkage void spurious_interrupt_bug(void); @@ -77,6 +78,7 @@ dotraplinkage void do_stack_segment(struct pt_regs *, long); dotraplinkage void do_double_fault(struct pt_regs *, long); #endif dotraplinkage void do_general_protection(struct pt_regs *, long); +dotraplinkage void do_control_protection(struct pt_regs *, long); dotraplinkage void do_page_fault(struct pt_regs *, unsigned long); dotraplinkage void do_spurious_interrupt_bug(struct pt_regs *, long); dotraplinkage void do_coprocessor_error(struct pt_regs *, long); @@ -142,6 +144,7 @@ enum { X86_TRAP_AC, /* 17, Alignment Check */ X86_TRAP_MC, /* 18, Machine Check */ X86_TRAP_XF, /* 19, SIMD Floating-Point Exception */ + X86_TRAP_CP = 21, /* 21 Control Protection Fault */ X86_TRAP_IRET = 32, /* 32, IRET Exception */ }; diff --git a/arch/x86/kernel/idt.c b/arch/x86/kernel/idt.c index 74383a3780dc..aa0229e1962d 100644 --- a/arch/x86/kernel/idt.c +++ b/arch/x86/kernel/idt.c @@ -103,6 +103,10 @@ static const __initconst struct idt_data def_idts[] = { #elif defined(CONFIG_X86_32) SYSG(IA32_SYSCALL_VECTOR, entry_INT80_32), #endif + +#ifdef CONFIG_X86_INTEL_CET + INTG(X86_TRAP_CP, control_protection), +#endif }; /* diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index e6db475164ed..21a713b96148 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -578,6 +578,64 @@ do_general_protection(struct pt_regs *regs, long error_code) } NOKPROBE_SYMBOL(do_general_protection); +static const char *control_protection_err[] = +{ + "unknown", + "near-ret", + "far-ret/iret", + "endbranch", + "rstorssp", + "setssbsy", +}; + +/* + * When a control protection exception occurs, send a signal + * to the responsible application. Currently, control + * protection is only enabled for the user mode. This + * exception should not come from the kernel mode. + */ +dotraplinkage void +do_control_protection(struct pt_regs *regs, long error_code) +{ + struct task_struct *tsk; + + RCU_LOCKDEP_WARN(!rcu_is_watching(), "entry code didn't wake RCU"); + if (notify_die(DIE_TRAP, "control protection fault", regs, + error_code, X86_TRAP_CP, SIGSEGV) == NOTIFY_STOP) + return; + cond_local_irq_enable(regs); + + if (!user_mode(regs)) + die("kernel control protection fault", regs, error_code); + + if (!static_cpu_has(X86_FEATURE_SHSTK) && + !static_cpu_has(X86_FEATURE_IBT)) + WARN_ONCE(1, "CET is disabled but got control " + "protection fault\n"); + + tsk = current; + tsk->thread.error_code = error_code; + tsk->thread.trap_nr = X86_TRAP_CP; + + if (show_unhandled_signals && unhandled_signal(tsk, SIGSEGV) && + printk_ratelimit()) { + unsigned int max_err; + + max_err = ARRAY_SIZE(control_protection_err) - 1; + if ((error_code < 0) || (error_code > max_err)) + error_code = 0; + pr_info("%s[%d] control protection ip:%lx sp:%lx error:%lx(%s)", + tsk->comm, task_pid_nr(tsk), + regs->ip, regs->sp, error_code, + control_protection_err[error_code]); + print_vma_addr(" in ", regs->ip); + pr_cont("\n"); + } + + force_sig_info(SIGSEGV, SEND_SIG_PRIV, tsk); +} +NOKPROBE_SYMBOL(do_control_protection); + dotraplinkage void notrace do_int3(struct pt_regs *regs, long error_code) { #ifdef CONFIG_DYNAMIC_FTRACE