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=-9.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 9FFEAC282DD for ; Wed, 8 Jan 2020 15:28:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6451820673 for ; Wed, 8 Jan 2020 15:28:32 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=citrix.com header.i=@citrix.com header.b="dY/DWHhY" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728901AbgAHP2b (ORCPT ); Wed, 8 Jan 2020 10:28:31 -0500 Received: from esa5.hc3370-68.iphmx.com ([216.71.155.168]:3495 "EHLO esa5.hc3370-68.iphmx.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728375AbgAHP2T (ORCPT ); Wed, 8 Jan 2020 10:28:19 -0500 X-Greylist: delayed 426 seconds by postgrey-1.27 at vger.kernel.org; Wed, 08 Jan 2020 10:28:18 EST DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=citrix.com; s=securemail; t=1578497299; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version; bh=ZJuSUJ02rylweO0QTHeZK87XYdE2eEfNMSYEfZ4ISFU=; b=dY/DWHhYkkxgjmkULTxYvRMfaZA3Jglr4+ai0bo1e0ndy2jdRPGmS5bg iOeukYOWlrd6a4uWoBMP4u2in+AZ5ypO9e7xX5WMpXE9E81o0KOk9nU79 rVHRlIrjMpTOMRsJ8/MqQiEqC0kPcz23sPGnEuwMqNpWS0eCFFfmDBxA/ I=; Authentication-Results: esa5.hc3370-68.iphmx.com; dkim=none (message not signed) header.i=none; spf=None smtp.pra=sergey.dyasli@citrix.com; spf=Pass smtp.mailfrom=sergey.dyasli@citrix.com; spf=None smtp.helo=postmaster@mail.citrix.com Received-SPF: None (esa5.hc3370-68.iphmx.com: no sender authenticity information available from domain of sergey.dyasli@citrix.com) identity=pra; client-ip=162.221.158.21; receiver=esa5.hc3370-68.iphmx.com; envelope-from="sergey.dyasli@citrix.com"; x-sender="sergey.dyasli@citrix.com"; x-conformance=sidf_compatible Received-SPF: Pass (esa5.hc3370-68.iphmx.com: domain of sergey.dyasli@citrix.com designates 162.221.158.21 as permitted sender) identity=mailfrom; client-ip=162.221.158.21; receiver=esa5.hc3370-68.iphmx.com; envelope-from="sergey.dyasli@citrix.com"; x-sender="sergey.dyasli@citrix.com"; x-conformance=sidf_compatible; x-record-type="v=spf1"; x-record-text="v=spf1 ip4:209.167.231.154 ip4:178.63.86.133 ip4:195.66.111.40/30 ip4:85.115.9.32/28 ip4:199.102.83.4 ip4:192.28.146.160 ip4:192.28.146.107 ip4:216.52.6.88 ip4:216.52.6.188 ip4:162.221.158.21 ip4:162.221.156.83 ip4:168.245.78.127 ~all" Received-SPF: None (esa5.hc3370-68.iphmx.com: no sender authenticity information available from domain of postmaster@mail.citrix.com) identity=helo; client-ip=162.221.158.21; receiver=esa5.hc3370-68.iphmx.com; envelope-from="sergey.dyasli@citrix.com"; x-sender="postmaster@mail.citrix.com"; x-conformance=sidf_compatible IronPort-SDR: DX+ggOVcUV+qjAM+GH2sUSi46yljxph9UiDZ5OvdtBvqC5kMO1PziVlbeWDiErFsikLJupbr6j e1GJp5zCy/6F3zEoqeeNBUnp1jCorCX2Lv0Aiur8r6exMyKmwDqJuw2jGva+/nJJXFvTQ2Ugl7 MsXEecRWjr/VWKfr79oqpWhGuobCwHKJmBbBKn4tqnGTrqWdR7mqh2Qt3c/YNqtAyzHNee9e/R zXaizezM7fqVpwm8zpKNd8k535daqotbAfc1B7wEgWYPCbpvlXlweSc7xS8pQwblpvCKKTD4np 1yI= X-SBRS: 2.7 X-MesageID: 11004137 X-Ironport-Server: esa5.hc3370-68.iphmx.com X-Remote-IP: 162.221.158.21 X-Policy: $RELAYED X-IronPort-AV: E=Sophos;i="5.69,410,1571716800"; d="scan'208";a="11004137" From: Sergey Dyasli To: , , , CC: Andrey Ryabinin , Alexander Potapenko , Dmitry Vyukov , Boris Ostrovsky , Juergen Gross , "Stefano Stabellini" , George Dunlap , Ross Lagerwall , Andrew Morton , Sergey Dyasli Subject: [PATCH v1 2/4] x86/xen: add basic KASAN support for PV kernel Date: Wed, 8 Jan 2020 15:20:58 +0000 Message-ID: <20200108152100.7630-3-sergey.dyasli@citrix.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200108152100.7630-1-sergey.dyasli@citrix.com> References: <20200108152100.7630-1-sergey.dyasli@citrix.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This enables to use Outline instrumentation for Xen PV kernels. KASAN_INLINE and KASAN_VMALLOC options currently lead to boot crashes and hence disabled. Signed-off-by: Sergey Dyasli --- RFC --> v1: - New functions with declarations in xen/xen-ops.h - Fixed the issue with free_kernel_image_pages() with the help of xen_pv_kasan_unpin_pgd() --- arch/x86/mm/kasan_init_64.c | 12 ++++++++++++ arch/x86/xen/Makefile | 7 +++++++ arch/x86/xen/enlighten_pv.c | 3 +++ arch/x86/xen/mmu_pv.c | 39 +++++++++++++++++++++++++++++++++++++ drivers/xen/Makefile | 2 ++ include/xen/xen-ops.h | 4 ++++ kernel/Makefile | 2 ++ lib/Kconfig.kasan | 3 ++- 8 files changed, 71 insertions(+), 1 deletion(-) diff --git a/arch/x86/mm/kasan_init_64.c b/arch/x86/mm/kasan_init_64.c index cf5bc37c90ac..902a6a152d33 100644 --- a/arch/x86/mm/kasan_init_64.c +++ b/arch/x86/mm/kasan_init_64.c @@ -13,6 +13,9 @@ #include #include +#include +#include + #include #include #include @@ -332,6 +335,11 @@ void __init kasan_early_init(void) for (i = 0; pgtable_l5_enabled() && i < PTRS_PER_P4D; i++) kasan_early_shadow_p4d[i] = __p4d(p4d_val); + if (xen_pv_domain()) { + pgd_t *pv_top_pgt = xen_pv_kasan_early_init(); + kasan_map_early_shadow(pv_top_pgt); + } + kasan_map_early_shadow(early_top_pgt); kasan_map_early_shadow(init_top_pgt); } @@ -369,6 +377,8 @@ void __init kasan_init(void) __pgd(__pa(tmp_p4d_table) | _KERNPG_TABLE)); } + xen_pv_kasan_pin_pgd(early_top_pgt); + load_cr3(early_top_pgt); __flush_tlb_all(); @@ -433,6 +443,8 @@ void __init kasan_init(void) load_cr3(init_top_pgt); __flush_tlb_all(); + xen_pv_kasan_unpin_pgd(early_top_pgt); + /* * kasan_early_shadow_page has been used as early shadow memory, thus * it may contain some garbage. Now we can clear and write protect it, diff --git a/arch/x86/xen/Makefile b/arch/x86/xen/Makefile index 084de77a109e..102fad0b0bca 100644 --- a/arch/x86/xen/Makefile +++ b/arch/x86/xen/Makefile @@ -1,3 +1,10 @@ +KASAN_SANITIZE_enlighten_pv.o := n +KASAN_SANITIZE_enlighten.o := n +KASAN_SANITIZE_irq.o := n +KASAN_SANITIZE_mmu_pv.o := n +KASAN_SANITIZE_p2m.o := n +KASAN_SANITIZE_multicalls.o := n + # SPDX-License-Identifier: GPL-2.0 OBJECT_FILES_NON_STANDARD_xen-asm_$(BITS).o := y diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c index ae4a41ca19f6..27de55699f24 100644 --- a/arch/x86/xen/enlighten_pv.c +++ b/arch/x86/xen/enlighten_pv.c @@ -72,6 +72,7 @@ #include #include #include +#include #ifdef CONFIG_ACPI #include @@ -1231,6 +1232,8 @@ asmlinkage __visible void __init xen_start_kernel(void) /* Get mfn list */ xen_build_dynamic_phys_to_machine(); + kasan_early_init(); + /* * Set up kernel GDT and segment registers, mainly so that * -fstack-protector code can be executed. diff --git a/arch/x86/xen/mmu_pv.c b/arch/x86/xen/mmu_pv.c index c8dbee62ec2a..cf6ff214d9ea 100644 --- a/arch/x86/xen/mmu_pv.c +++ b/arch/x86/xen/mmu_pv.c @@ -1771,6 +1771,36 @@ static void __init set_page_prot(void *addr, pgprot_t prot) { return set_page_prot_flags(addr, prot, UVMF_NONE); } + +pgd_t * __init xen_pv_kasan_early_init(void) +{ + /* PV page tables must be read-only */ + set_page_prot(kasan_early_shadow_pud, PAGE_KERNEL_RO); + set_page_prot(kasan_early_shadow_pmd, PAGE_KERNEL_RO); + set_page_prot(kasan_early_shadow_pte, PAGE_KERNEL_RO); + + /* Return a pointer to the initial PV page tables */ + return (pgd_t *)xen_start_info->pt_base; +} + +void __init xen_pv_kasan_pin_pgd(pgd_t *pgd) +{ + if (!xen_pv_domain()) + return; + + set_page_prot(pgd, PAGE_KERNEL_RO); + pin_pagetable_pfn(MMUEXT_PIN_L4_TABLE, PFN_DOWN(__pa_symbol(pgd))); +} + +void __init xen_pv_kasan_unpin_pgd(pgd_t *pgd) +{ + if (!xen_pv_domain()) + return; + + pin_pagetable_pfn(MMUEXT_UNPIN_TABLE, PFN_DOWN(__pa_symbol(pgd))); + set_page_prot(pgd, PAGE_KERNEL); +} + #ifdef CONFIG_X86_32 static void __init xen_map_identity_early(pmd_t *pmd, unsigned long max_pfn) { @@ -1943,6 +1973,15 @@ void __init xen_setup_kernel_pagetable(pgd_t *pgd, unsigned long max_pfn) if (i && i < pgd_index(__START_KERNEL_map)) init_top_pgt[i] = ((pgd_t *)xen_start_info->pt_base)[i]; +#ifdef CONFIG_KASAN + /* + * Copy KASAN mappings + * ffffec0000000000 - fffffbffffffffff (=44 bits) kasan shadow memory (16TB) + */ + for (i = 0xec0 >> 3; i < 0xfc0 >> 3; i++) + init_top_pgt[i] = ((pgd_t *)xen_start_info->pt_base)[i]; +#endif + /* Make pagetable pieces RO */ set_page_prot(init_top_pgt, PAGE_KERNEL_RO); set_page_prot(level3_ident_pgt, PAGE_KERNEL_RO); diff --git a/drivers/xen/Makefile b/drivers/xen/Makefile index 0c4efa6fe450..1e9e1e41c0a8 100644 --- a/drivers/xen/Makefile +++ b/drivers/xen/Makefile @@ -1,4 +1,6 @@ # SPDX-License-Identifier: GPL-2.0 +KASAN_SANITIZE_features.o := n + obj-$(CONFIG_HOTPLUG_CPU) += cpu_hotplug.o obj-y += grant-table.o features.o balloon.o manage.o preempt.o time.o obj-y += mem-reservation.o diff --git a/include/xen/xen-ops.h b/include/xen/xen-ops.h index d89969aa9942..91d66520f0a3 100644 --- a/include/xen/xen-ops.h +++ b/include/xen/xen-ops.h @@ -241,4 +241,8 @@ static inline void xen_preemptible_hcall_end(void) #endif /* CONFIG_PREEMPT */ +pgd_t *xen_pv_kasan_early_init(void); +void xen_pv_kasan_pin_pgd(pgd_t *pgd); +void xen_pv_kasan_unpin_pgd(pgd_t *pgd); + #endif /* INCLUDE_XEN_OPS_H */ diff --git a/kernel/Makefile b/kernel/Makefile index f2cc0d118a0b..1da6fd93c00c 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -12,6 +12,8 @@ obj-y = fork.o exec_domain.o panic.o \ notifier.o ksysfs.o cred.o reboot.o \ async.o range.o smpboot.o ucount.o +KASAN_SANITIZE_cpu.o := n + obj-$(CONFIG_MODULES) += kmod.o obj-$(CONFIG_MULTIUSER) += groups.o diff --git a/lib/Kconfig.kasan b/lib/Kconfig.kasan index 81f5464ea9e1..429a638625ea 100644 --- a/lib/Kconfig.kasan +++ b/lib/Kconfig.kasan @@ -98,6 +98,7 @@ config KASAN_OUTLINE config KASAN_INLINE bool "Inline instrumentation" + depends on !XEN_PV help Compiler directly inserts code checking shadow memory before memory accesses. This is faster than outline (in some workloads @@ -147,7 +148,7 @@ config KASAN_SW_TAGS_IDENTIFY config KASAN_VMALLOC bool "Back mappings in vmalloc space with real shadow memory" - depends on KASAN && HAVE_ARCH_KASAN_VMALLOC + depends on KASAN && HAVE_ARCH_KASAN_VMALLOC && !XEN_PV help By default, the shadow region for vmalloc space is the read-only zero page. This means that KASAN cannot detect errors involving -- 2.17.1