From patchwork Sat May 29 08:03:40 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Liu Shixin X-Patchwork-Id: 12287713 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=-17.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham 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 2C84CC47082 for ; Sat, 29 May 2021 07:31:52 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id C4B8A611AB for ; Sat, 29 May 2021 07:31:51 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C4B8A611AB Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=huawei.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-ID:Date:Subject:CC :To:From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=0qvLeqaaePNvnq1r8vWR2cE7l6Ch/rFgkP2tX2GVVdY=; b=szxoImgwhWtaMm 4quGEbeluskmAmTxsbeTjFmgXDDrdLhbrZue6AZbSDfZ99YP9BRLlHEbABhVCpnqnjCg2IJh0STb4 HF0iG9x2Jm3sZ/zp6UxAZbp6TXBA5WEae14ghSVNS+ar3rHwKO03z68phNz/L0Kn1trTFeTDyMn43 k3MVnilmwljIhHzcfEXoCDeMKDiCgihsozEg6S+xN+7Us3W15fdNpolHtXROVKX8BO1sOxGQX9Vfi P5/vAyJcrzW0aCYY6v87Ds+V/ZsQE0XJdx58NyXLBA1jJdw53/wJ8RIQZ3xhOgFdDKy+6c6qTud9C QtCSY9bDVYG0mj4OfAEQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1lmtRR-003oaz-4z; Sat, 29 May 2021 07:31:29 +0000 Received: from szxga01-in.huawei.com ([45.249.212.187]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1lmtRN-003oVr-GQ for linux-riscv@lists.infradead.org; Sat, 29 May 2021 07:31:27 +0000 Received: from dggemv704-chm.china.huawei.com (unknown [172.30.72.56]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4FsY7g50KqzYnXs; Sat, 29 May 2021 15:28:31 +0800 (CST) Received: from dggpemm500009.china.huawei.com (7.185.36.225) by dggemv704-chm.china.huawei.com (10.3.19.47) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Sat, 29 May 2021 15:31:12 +0800 Received: from huawei.com (10.175.113.32) by dggpemm500009.china.huawei.com (7.185.36.225) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Sat, 29 May 2021 15:31:12 +0800 From: Liu Shixin To: Paul Walmsley , Palmer Dabbelt , Albert Ou , Alexander Potapenko , Marco Elver , Dmitry Vyukov CC: , , , Liu Shixin Subject: [PATCH -next] riscv: Enable KFENCE for riscv64 Date: Sat, 29 May 2021 16:03:40 +0800 Message-ID: <20210529080340.2987212-1-liushixin2@huawei.com> X-Mailer: git-send-email 2.18.0.huawei.25 MIME-Version: 1.0 X-Originating-IP: [10.175.113.32] X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) To dggpemm500009.china.huawei.com (7.185.36.225) X-CFilter-Loop: Reflected X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210529_003125_959584_3C8094D4 X-CRM114-Status: GOOD ( 17.24 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org Add architecture specific implementation details for KFENCE and enable KFENCE for the riscv64 architecture. In particular, this implements the required interface in . KFENCE requires that attributes for pages from its memory pool can individually be set. Therefore, force the kfence pool to be mapped at page granularity. Testing this patch using the testcases in kfence_test.c and all passed. Signed-off-by: Liu Shixin Reviewed-by: Kefeng Wang --- 1. Add helper function split_pmd_page() which is used to split a pmd to ptes. 2. Add the judgment on the result of pte_alloc_one_kernel(). arch/riscv/Kconfig | 1 + arch/riscv/include/asm/kfence.h | 63 +++++++++++++++++++++++++++++++++ arch/riscv/mm/fault.c | 11 +++++- 3 files changed, 74 insertions(+), 1 deletion(-) create mode 100644 arch/riscv/include/asm/kfence.h diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index 4982130064ef..2f4903a7730f 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -65,6 +65,7 @@ config RISCV select HAVE_ARCH_JUMP_LABEL_RELATIVE select HAVE_ARCH_KASAN if MMU && 64BIT select HAVE_ARCH_KASAN_VMALLOC if MMU && 64BIT + select HAVE_ARCH_KFENCE if MMU && 64BIT select HAVE_ARCH_KGDB select HAVE_ARCH_KGDB_QXFER_PKT select HAVE_ARCH_MMAP_RND_BITS if MMU diff --git a/arch/riscv/include/asm/kfence.h b/arch/riscv/include/asm/kfence.h new file mode 100644 index 000000000000..d887a54042aa --- /dev/null +++ b/arch/riscv/include/asm/kfence.h @@ -0,0 +1,63 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef _ASM_RISCV_KFENCE_H +#define _ASM_RISCV_KFENCE_H + +#include +#include +#include +#include + +static inline int split_pmd_page(unsigned long addr) +{ + int i; + unsigned long pfn = PFN_DOWN(__pa((addr & PMD_MASK))); + pmd_t *pmd = pmd_off_k(addr); + pte_t *pte = pte_alloc_one_kernel(&init_mm); + + if (!pte) + return -ENOMEM; + + for (i = 0; i < PTRS_PER_PTE; i++) + set_pte(pte + i, pfn_pte(pfn + i, PAGE_KERNEL)); + set_pmd(pmd, pfn_pmd(PFN_DOWN(__pa(pte)), PAGE_TABLE)); + + flush_tlb_kernel_range(addr, addr + PMD_SIZE); + return 0; +} + +static inline bool arch_kfence_init_pool(void) +{ + int ret; + unsigned long addr; + pmd_t *pmd; + + for (addr = (unsigned long)__kfence_pool; is_kfence_address((void *)addr); + addr += PAGE_SIZE) { + pmd = pmd_off_k(addr); + + if (pmd_leaf(*pmd)) { + ret = split_pmd_page(addr); + if (ret) + return false; + } + } + + return true; +} + +static inline bool kfence_protect_page(unsigned long addr, bool protect) +{ + pte_t *pte = virt_to_kpte(addr); + + if (protect) + set_pte(pte, __pte(pte_val(*pte) & ~_PAGE_PRESENT)); + else + set_pte(pte, __pte(pte_val(*pte) | _PAGE_PRESENT)); + + flush_tlb_kernel_range(addr, addr + PAGE_SIZE); + + return true; +} + +#endif /* _ASM_RISCV_KFENCE_H */ diff --git a/arch/riscv/mm/fault.c b/arch/riscv/mm/fault.c index 096463cc6fff..aa08dd2f8fae 100644 --- a/arch/riscv/mm/fault.c +++ b/arch/riscv/mm/fault.c @@ -14,6 +14,7 @@ #include #include #include +#include #include #include @@ -45,7 +46,15 @@ static inline void no_context(struct pt_regs *regs, unsigned long addr) * Oops. The kernel tried to access some bad page. We'll have to * terminate things with extreme prejudice. */ - msg = (addr < PAGE_SIZE) ? "NULL pointer dereference" : "paging request"; + if (addr < PAGE_SIZE) + msg = "NULL pointer dereference"; + else { + if (kfence_handle_page_fault(addr, regs->cause == EXC_STORE_PAGE_FAULT, regs)) + return; + + msg = "paging request"; + } + die_kernel_fault(msg, addr, regs); }