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=-20.4 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 614F3C43469 for ; Mon, 21 Sep 2020 13:27:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 306B32076E for ; Mon, 21 Sep 2020 13:27:18 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="qL2wY6WB" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727293AbgIUN0z (ORCPT ); Mon, 21 Sep 2020 09:26:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59730 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727193AbgIUN0m (ORCPT ); Mon, 21 Sep 2020 09:26:42 -0400 Received: from mail-yb1-xb49.google.com (mail-yb1-xb49.google.com [IPv6:2607:f8b0:4864:20::b49]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2CA4BC0613CF for ; Mon, 21 Sep 2020 06:26:42 -0700 (PDT) Received: by mail-yb1-xb49.google.com with SMTP id p187so13116640ybg.14 for ; Mon, 21 Sep 2020 06:26:42 -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=wt63fMbRtF63+v7/GuudoZYJcaqBUfqT28LRHuRusC0=; b=qL2wY6WBUQcx5pj52oZp6zYoEVKIicz7S4B4rLCTdAz6PS5lHgO06blQ7f6xllHz2o hagGVVZ/7022UmkPMfpMkPPKNZDUdgN63y58z5Wfn/b4uf508D80p+A1ZuFXfGAkimes i74FDyotzaUDEAHidRxPTcdVhHau2t6wLifADNQe4rPzoE3e+aWQkaHadVV09M08zOf4 oK+GxDQ+bjyvYR/vvbrC2I5GIiNu8ZKvhpcg4822VkRb+LENM1snc9rW613oonoj5WHN 8+tuJRn5I/69FohHkuBzfpzx0pGYBsGBPz7yJAAa6pfKkS/ktySeqDYNwSHOS1IJ7BrI EDJA== 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=wt63fMbRtF63+v7/GuudoZYJcaqBUfqT28LRHuRusC0=; b=nTX8qZ3Sr8IlCzLXXFxbgvvNs8ydJrWmFF9zcdm9lu9cxaHXqU2vO8dc6dxuHCa9eu 0DwfK0r4lH3NAWkyIIwxTHJo+qeZvPaKobyBNJdDiTU5dSFZsL4LvUqdZ/0PVJtor8pm tHiwQx6zRa3isrsTxC9I6pa1XStL2KvWv42vO0KrixO96SvJpfIyF6jMsJaEgnRZEsXf VJ9oO9PiJjiwAUc9BSyN9B/muuZlfE+syzHNdasoA7zyxwVVv33HgsRjeKdC89OoEsb/ STUAhIImDZeIOrdBAP9TJLMMq5efUiS1JF9cby5DRN76vK0SWyFpdA+doDmdW3o9UdCn uGUA== X-Gm-Message-State: AOAM532Vy+yJFffC8qUbDSj02WsL/hcBnIcFJ0W+Qg7oZZbmacqF0Lsw 0SV3fEIuS4lLDnZgclZV86KriIjmNw== X-Google-Smtp-Source: ABdhPJzdGcwUC1pBrVmyD+23TVrmfQ31wFp42KfuDHSbJFG8Jn48HEPqt8sIw6l6hPH7bByrLSO6bhg5eg== 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:a25:69cb:: with SMTP id e194mr49735261ybc.243.1600694801234; Mon, 21 Sep 2020 06:26:41 -0700 (PDT) Date: Mon, 21 Sep 2020 15:26:03 +0200 In-Reply-To: <20200921132611.1700350-1-elver@google.com> Message-Id: <20200921132611.1700350-3-elver@google.com> Mime-Version: 1.0 References: <20200921132611.1700350-1-elver@google.com> X-Mailer: git-send-email 2.28.0.681.g6f77f65b4e-goog Subject: [PATCH v3 02/10] 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-kernel@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 --- 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..cf09e377faf9 --- /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_ALIGNMENT 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: * -- 2.28.0.681.g6f77f65b4e-goog