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=-20.9 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT,USER_IN_DEF_DKIM_WL 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 0B79CC47426 for ; Tue, 29 Sep 2020 13:39:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AB026208FE for ; Tue, 29 Sep 2020 13:39:11 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="d25sdqTR" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730018AbgI2Ni5 (ORCPT ); Tue, 29 Sep 2020 09:38:57 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57242 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729989AbgI2Nit (ORCPT ); Tue, 29 Sep 2020 09:38:49 -0400 Received: from mail-qt1-x84a.google.com (mail-qt1-x84a.google.com [IPv6:2607:f8b0:4864:20::84a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E85ECC061755 for ; Tue, 29 Sep 2020 06:38:47 -0700 (PDT) Received: by mail-qt1-x84a.google.com with SMTP id a16so2988227qtj.7 for ; Tue, 29 Sep 2020 06:38:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=sender:date:in-reply-to:message-id:mime-version:references:subject :from:to:cc; bh=1b8StUxuKVuYd1wam6EMRlTfs7xw+c/0eMbKAsoXFrU=; b=d25sdqTRKnNfZKW7kuWY3HtLW+C+GmUN+n5VmyhHB1XUqvDqPmidO1bbCNS4iSezQf OAi00db1yuNkLFRlJjsI0//2wlaaJSYdIgsqT0SmyOgTFQHU/9Ddo2tknD95IflErqt7 FQyrL+BerDfu2w3Fi4dSIThjb7Sn5W13yeIJYbq9bJLqKpNNfrukW9VsL/Lr4zN7pCoV uCdz8jQ0S9m83vb/3Nwejb9iKbHY6c8ogUQwLPIJs9nTP+o2ho1GpDXhihOc7GrasyU/ hjUBS/6za9IXrJ0HAMQj2LK3RHq8BKyZkDFimnmcsQGSNSdGCX8jDIUu70lSL9SuEm06 rK1w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=1b8StUxuKVuYd1wam6EMRlTfs7xw+c/0eMbKAsoXFrU=; b=ujtRTVlFLzOwBFee9AvN7D04coHQd7FU5HlhqnFk/5pyj6eX3llg9e6JBL4ELif/7A X0s42wSTMZTeqPjOqKE5boEoDd4wBZ3SIu07gs4BLpkAc2yZhjUDSliy1zqelf1fWg4p 5J0gt4KEm5vWf3jh1kupvWam3WXUHsAr52yAZgnQ6Ui1hBV03+2JNvqZytSrHODuY5cL meYUjbAc8RQCoMdUPZrLdZFzqj6lgePyM0701n1Uc+TgCwzKx9Z5IR4ob6bIJeKTFh7O 3j62rqzC9y1wlhB2zuRq+eY5PIvWTzJlR/Rf8Y9SykkN5fN0CUNvJCzjojZl/zdgfsjA h4cQ== X-Gm-Message-State: AOAM532BwbZ5NE7v721HtKDO9GBw11lSqQT6nwOE3KY5K7sfU/IDjA/w 9q6eEuUVnH0VeT8F5Ze2Oz3ALO1DFw== X-Google-Smtp-Source: ABdhPJwyguPmT4Rf0i2UiKmi5OgPQew05alW5ddxHiPxbIGHcxizsfd5RmyXpXS3OYqxt7SfjqAmV+7UQA== Sender: "elver via sendgmr" X-Received: from elver.muc.corp.google.com ([2a00:79e0:15:13:f693:9fff:fef4:2449]) (user=elver job=sendgmr) by 2002:ad4:4e4e:: with SMTP id eb14mr4552265qvb.41.1601386726953; Tue, 29 Sep 2020 06:38:46 -0700 (PDT) Date: Tue, 29 Sep 2020 15:38:05 +0200 In-Reply-To: <20200929133814.2834621-1-elver@google.com> Message-Id: <20200929133814.2834621-3-elver@google.com> Mime-Version: 1.0 References: <20200929133814.2834621-1-elver@google.com> X-Mailer: git-send-email 2.28.0.709.gb0816b6eb0-goog Subject: [PATCH v4 02/11] x86, kfence: enable KFENCE for x86 From: Marco Elver To: elver@google.com, akpm@linux-foundation.org, glider@google.com Cc: hpa@zytor.com, paulmck@kernel.org, andreyknvl@google.com, aryabinin@virtuozzo.com, luto@kernel.org, bp@alien8.de, catalin.marinas@arm.com, cl@linux.com, dave.hansen@linux.intel.com, rientjes@google.com, dvyukov@google.com, edumazet@google.com, gregkh@linuxfoundation.org, hdanton@sina.com, mingo@redhat.com, jannh@google.com, Jonathan.Cameron@huawei.com, corbet@lwn.net, iamjoonsoo.kim@lge.com, keescook@chromium.org, mark.rutland@arm.com, penberg@kernel.org, peterz@infradead.org, sjpark@amazon.com, tglx@linutronix.de, vbabka@suse.cz, will@kernel.org, x86@kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com, linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org From: Alexander Potapenko Add architecture specific implementation details for KFENCE and enable KFENCE for the x86 architecture. In particular, this implements the required interface in for setting up the pool and providing helper functions for protecting and unprotecting pages. For x86, we need to ensure that the pool uses 4K pages, which is done using the set_memory_4k() helper function. Reviewed-by: Dmitry Vyukov Co-developed-by: Marco Elver Signed-off-by: Marco Elver Signed-off-by: Alexander Potapenko --- v4: * Define __kfence_pool_attrs. --- arch/x86/Kconfig | 2 ++ arch/x86/include/asm/kfence.h | 60 +++++++++++++++++++++++++++++++++++ arch/x86/mm/fault.c | 4 +++ 3 files changed, 66 insertions(+) create mode 100644 arch/x86/include/asm/kfence.h diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 7101ac64bb20..e22dc722698c 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -144,6 +144,8 @@ config X86 select HAVE_ARCH_JUMP_LABEL_RELATIVE select HAVE_ARCH_KASAN if X86_64 select HAVE_ARCH_KASAN_VMALLOC if X86_64 + select HAVE_ARCH_KFENCE + select HAVE_ARCH_KFENCE_STATIC_POOL select HAVE_ARCH_KGDB select HAVE_ARCH_MMAP_RND_BITS if MMU select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT diff --git a/arch/x86/include/asm/kfence.h b/arch/x86/include/asm/kfence.h new file mode 100644 index 000000000000..98fb1cd80026 --- /dev/null +++ b/arch/x86/include/asm/kfence.h @@ -0,0 +1,60 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef _ASM_X86_KFENCE_H +#define _ASM_X86_KFENCE_H + +#include +#include + +#include +#include +#include +#include + +/* The alignment should be at least a 4K page. */ +#define __kfence_pool_attrs __aligned(PAGE_SIZE) + +/* + * The page fault handler entry function, up to which the stack trace is + * truncated in reports. + */ +#define KFENCE_SKIP_ARCH_FAULT_HANDLER "asm_exc_page_fault" + +/* Force 4K pages for __kfence_pool. */ +static inline bool arch_kfence_initialize_pool(void) +{ + unsigned long addr; + + for (addr = (unsigned long)__kfence_pool; is_kfence_address((void *)addr); + addr += PAGE_SIZE) { + unsigned int level; + + if (!lookup_address(addr, &level)) + return false; + + if (level != PG_LEVEL_4K) + set_memory_4k(addr, 1); + } + + return true; +} + +/* Protect the given page and flush TLBs. */ +static inline bool kfence_protect_page(unsigned long addr, bool protect) +{ + unsigned int level; + pte_t *pte = lookup_address(addr, &level); + + if (!pte || level != PG_LEVEL_4K) + return false; + + if (protect) + set_pte(pte, __pte(pte_val(*pte) & ~_PAGE_PRESENT)); + else + set_pte(pte, __pte(pte_val(*pte) | _PAGE_PRESENT)); + + flush_tlb_one_kernel(addr); + return true; +} + +#endif /* _ASM_X86_KFENCE_H */ diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index 6e3e8a124903..423e15ad5eb6 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -9,6 +9,7 @@ #include /* oops_begin/end, ... */ #include /* search_exception_tables */ #include /* max_low_pfn */ +#include /* kfence_handle_page_fault */ #include /* NOKPROBE_SYMBOL, ... */ #include /* kmmio_handler, ... */ #include /* perf_sw_event */ @@ -701,6 +702,9 @@ no_context(struct pt_regs *regs, unsigned long error_code, } #endif + if (kfence_handle_page_fault(address)) + return; + /* * 32-bit: * -- 2.28.0.709.gb0816b6eb0-goog