From patchwork Wed Jun 12 17:26:49 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Steve Capper X-Patchwork-Id: 10990497 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id EE9841515 for ; Wed, 12 Jun 2019 17:27:44 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id D7BA922A2A for ; Wed, 12 Jun 2019 17:27:44 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id CB2B0289BE; Wed, 12 Jun 2019 17:27:44 +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=-5.2 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 2E6CC22A2A for ; Wed, 12 Jun 2019 17:27:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=b/XjyQZXZLA+kuQ80/ekmfnyY0fg4V6aB5J3gba15S8=; b=SDq2FU0EvnmBWj QmxQ7rc14fx4aQHGkbwXh47J03zTgZKtqE9cRk5V1hrv9Oi5qv2FERcfVW//E/BF8Vw1vigP3+Kqm 3itDx7al8VRJjKO2ba1WLVHTfdFmPInyRS5EValSQ83++Csiutvy6um70RVYwvlJBcR0D94u23VHM kQV4IJSsskoxTpY88bs/FsHXpVyuss0muGTe4e2XfNlLzcv9b9tWmOyoyuiVkAyJMK0K0ctFnl6y9 1xFaDIvIFCdi6oKdDkuRXectwHd5hXbwbMk4nOnp8GfgWnA+9j4ZIUG7m/QX+UXbixBqEz86FtTXM wIhbS454MscuHTEfmd5Q==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1hb728-0006H0-G8; Wed, 12 Jun 2019 17:27:36 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1hb71n-0005qn-5B for linux-arm-kernel@lists.infradead.org; Wed, 12 Jun 2019 17:27:16 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id AA23B337; Wed, 12 Jun 2019 10:27:12 -0700 (PDT) Received: from capper-debian.arm.com (unknown [10.37.13.15]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 057FE3F246; Wed, 12 Jun 2019 10:27:10 -0700 (PDT) From: Steve Capper To: linux-arm-kernel@lists.infradead.org Subject: [PATCH v3 01/10] arm64: mm: Flip kernel VA space Date: Wed, 12 Jun 2019 18:26:49 +0100 Message-Id: <20190612172658.28522-2-steve.capper@arm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190612172658.28522-1-steve.capper@arm.com> References: <20190612172658.28522-1-steve.capper@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190612_102715_328948_BBAE906F X-CRM114-Status: GOOD ( 14.67 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: crecklin@redhat.com, ard.biesheuvel@linaro.org, marc.zyngier@arm.com, catalin.marinas@arm.com, bhsharma@redhat.com, will.deacon@arm.com Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP Put the direct linear map in the lower addresses of the kernel VA range and everything else in the higher ranges. This allows us to make room for an inline KASAN shadow that operates under both 48 and 52 bit kernel VA sizes. For example with a 52-bit VA, if KASAN_SHADOW_END < 0xFFF8000000000000 (it is in the lower addresses of the kernel VA range), this will be below the start of the minimum 48-bit kernel VA address of 0xFFFF000000000000. We need to adjust: *) KASAN shadow region placement logic, *) KASAN_SHADOW_OFFSET computation logic, *) virt_to_phys, phys_to_virt checks, *) page table dumper. These are all small changes, that need to take place atomically, so they are bundled into this commit. Signed-off-by: Steve Capper --- arch/arm64/Makefile | 2 +- arch/arm64/include/asm/memory.h | 8 ++++---- arch/arm64/include/asm/pgtable.h | 2 +- arch/arm64/kernel/hibernate.c | 2 +- arch/arm64/mm/dump.c | 8 ++++---- arch/arm64/mm/init.c | 9 +-------- arch/arm64/mm/kasan_init.c | 6 +++--- arch/arm64/mm/mmu.c | 4 ++-- 8 files changed, 17 insertions(+), 24 deletions(-) diff --git a/arch/arm64/Makefile b/arch/arm64/Makefile index b025304bde46..2dad2ae6b181 100644 --- a/arch/arm64/Makefile +++ b/arch/arm64/Makefile @@ -115,7 +115,7 @@ KBUILD_AFLAGS += -DKASAN_SHADOW_SCALE_SHIFT=$(KASAN_SHADOW_SCALE_SHIFT) # - (1 << (64 - KASAN_SHADOW_SCALE_SHIFT)) # in 32-bit arithmetic KASAN_SHADOW_OFFSET := $(shell printf "0x%08x00000000\n" $$(( \ - (0xffffffff & (-1 << ($(CONFIG_ARM64_VA_BITS) - 32))) \ + (0xffffffff & (-1 << ($(CONFIG_ARM64_VA_BITS) - 1 - 32))) \ + (1 << ($(CONFIG_ARM64_VA_BITS) - 32 - $(KASAN_SHADOW_SCALE_SHIFT))) \ - (1 << (64 - 32 - $(KASAN_SHADOW_SCALE_SHIFT))) )) ) diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h index 8ffcf5a512bb..5cd2eb8cb424 100644 --- a/arch/arm64/include/asm/memory.h +++ b/arch/arm64/include/asm/memory.h @@ -49,9 +49,9 @@ */ #define VA_BITS (CONFIG_ARM64_VA_BITS) #define VA_START (UL(0xffffffffffffffff) - \ - (UL(1) << VA_BITS) + 1) -#define PAGE_OFFSET (UL(0xffffffffffffffff) - \ (UL(1) << (VA_BITS - 1)) + 1) +#define PAGE_OFFSET (UL(0xffffffffffffffff) - \ + (UL(1) << VA_BITS) + 1) #define KIMAGE_VADDR (MODULES_END) #define BPF_JIT_REGION_START (VA_START + KASAN_SHADOW_SIZE) #define BPF_JIT_REGION_SIZE (SZ_128M) @@ -59,7 +59,7 @@ #define MODULES_END (MODULES_VADDR + MODULES_VSIZE) #define MODULES_VADDR (BPF_JIT_REGION_END) #define MODULES_VSIZE (SZ_128M) -#define VMEMMAP_START (PAGE_OFFSET - VMEMMAP_SIZE) +#define VMEMMAP_START (-VMEMMAP_SIZE) #define PCI_IO_END (VMEMMAP_START - SZ_2M) #define PCI_IO_START (PCI_IO_END - PCI_IO_SIZE) #define FIXADDR_TOP (PCI_IO_START - SZ_2M) @@ -238,7 +238,7 @@ extern u64 vabits_user; * space. Testing the top bit for the start of the region is a * sufficient check. */ -#define __is_lm_address(addr) (!!((addr) & BIT(VA_BITS - 1))) +#define __is_lm_address(addr) (!((addr) & BIT(VA_BITS - 1))) #define __lm_to_phys(addr) (((addr) & ~PAGE_OFFSET) + PHYS_OFFSET) #define __kimg_to_phys(addr) ((addr) - kimage_voffset) diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h index 2c41b04708fe..d0ab784304e9 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -32,7 +32,7 @@ * and fixed mappings */ #define VMALLOC_START (MODULES_END) -#define VMALLOC_END (PAGE_OFFSET - PUD_SIZE - VMEMMAP_SIZE - SZ_64K) +#define VMALLOC_END (- PUD_SIZE - VMEMMAP_SIZE - SZ_64K) #define vmemmap ((struct page *)VMEMMAP_START - (memstart_addr >> PAGE_SHIFT)) diff --git a/arch/arm64/kernel/hibernate.c b/arch/arm64/kernel/hibernate.c index 9859e1178e6b..6ffcc32f35dd 100644 --- a/arch/arm64/kernel/hibernate.c +++ b/arch/arm64/kernel/hibernate.c @@ -497,7 +497,7 @@ int swsusp_arch_resume(void) rc = -ENOMEM; goto out; } - rc = copy_page_tables(tmp_pg_dir, PAGE_OFFSET, 0); + rc = copy_page_tables(tmp_pg_dir, PAGE_OFFSET, VA_START); if (rc) goto out; diff --git a/arch/arm64/mm/dump.c b/arch/arm64/mm/dump.c index 14fe23cd5932..ee4e5bea8944 100644 --- a/arch/arm64/mm/dump.c +++ b/arch/arm64/mm/dump.c @@ -30,6 +30,8 @@ #include static const struct addr_marker address_markers[] = { + { PAGE_OFFSET, "Linear Mapping start" }, + { VA_START, "Linear Mapping end" }, #ifdef CONFIG_KASAN { KASAN_SHADOW_START, "Kasan shadow start" }, { KASAN_SHADOW_END, "Kasan shadow end" }, @@ -43,10 +45,8 @@ static const struct addr_marker address_markers[] = { { PCI_IO_START, "PCI I/O start" }, { PCI_IO_END, "PCI I/O end" }, #ifdef CONFIG_SPARSEMEM_VMEMMAP - { VMEMMAP_START, "vmemmap start" }, - { VMEMMAP_START + VMEMMAP_SIZE, "vmemmap end" }, + { VMEMMAP_START, "vmemmap" }, #endif - { PAGE_OFFSET, "Linear mapping" }, { -1, NULL }, }; @@ -380,7 +380,7 @@ static void ptdump_initialize(void) static struct ptdump_info kernel_ptdump_info = { .mm = &init_mm, .markers = address_markers, - .base_addr = VA_START, + .base_addr = PAGE_OFFSET, }; void ptdump_check_wx(void) diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c index d2adffb81b5d..574ed1d4be19 100644 --- a/arch/arm64/mm/init.c +++ b/arch/arm64/mm/init.c @@ -311,7 +311,7 @@ static void __init fdt_enforce_memory_region(void) void __init arm64_memblock_init(void) { - const s64 linear_region_size = -(s64)PAGE_OFFSET; + const s64 linear_region_size = BIT(VA_BITS - 1); /* Handle linux,usable-memory-range property */ fdt_enforce_memory_region(); @@ -319,13 +319,6 @@ void __init arm64_memblock_init(void) /* Remove memory above our supported physical address size */ memblock_remove(1ULL << PHYS_MASK_SHIFT, ULLONG_MAX); - /* - * Ensure that the linear region takes up exactly half of the kernel - * virtual address space. This way, we can distinguish a linear address - * from a kernel/module/vmalloc address by testing a single bit. - */ - BUILD_BUG_ON(linear_region_size != BIT(VA_BITS - 1)); - /* * Select a suitable value for the base of physical memory. */ diff --git a/arch/arm64/mm/kasan_init.c b/arch/arm64/mm/kasan_init.c index 296de39ddee5..8066621052db 100644 --- a/arch/arm64/mm/kasan_init.c +++ b/arch/arm64/mm/kasan_init.c @@ -229,10 +229,10 @@ void __init kasan_init(void) kasan_map_populate(kimg_shadow_start, kimg_shadow_end, early_pfn_to_nid(virt_to_pfn(lm_alias(_text)))); - kasan_populate_early_shadow((void *)KASAN_SHADOW_START, - (void *)mod_shadow_start); + kasan_populate_early_shadow(kasan_mem_to_shadow((void *) VA_START), + (void *)mod_shadow_start); kasan_populate_early_shadow((void *)kimg_shadow_end, - kasan_mem_to_shadow((void *)PAGE_OFFSET)); + (void *)KASAN_SHADOW_END); if (kimg_shadow_start > mod_shadow_end) kasan_populate_early_shadow((void *)mod_shadow_end, diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index a1bfc4413982..16063ff10c6d 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -409,7 +409,7 @@ static phys_addr_t pgd_pgtable_alloc(int shift) static void __init create_mapping_noalloc(phys_addr_t phys, unsigned long virt, phys_addr_t size, pgprot_t prot) { - if (virt < VMALLOC_START) { + if ((virt >= VA_START) && (virt < VMALLOC_START)) { pr_warn("BUG: not creating mapping for %pa at 0x%016lx - outside kernel range\n", &phys, virt); return; @@ -436,7 +436,7 @@ void __init create_pgd_mapping(struct mm_struct *mm, phys_addr_t phys, static void update_mapping_prot(phys_addr_t phys, unsigned long virt, phys_addr_t size, pgprot_t prot) { - if (virt < VMALLOC_START) { + if ((virt >= VA_START) && (virt < VMALLOC_START)) { pr_warn("BUG: not updating mapping for %pa at 0x%016lx - outside kernel range\n", &phys, virt); return;