From patchwork Wed Aug 7 15:55:14 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Steve Capper X-Patchwork-Id: 11082387 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 A9363746 for ; Wed, 7 Aug 2019 15:56:09 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 989BD28A51 for ; Wed, 7 Aug 2019 15:56:09 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 8CF1428A5B; Wed, 7 Aug 2019 15:56:09 +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 DD7CE28A54 for ; Wed, 7 Aug 2019 15:56:08 +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=NI3AE0/IGSM0OE4QVe6v+GSw55SoFaK71O4SPghFMUs=; b=bV9Pl6ma5VZfF9 JFeYAvmfqWlCLV1b82o8H3Orwpsc9xShB4YOx4DTy9wG2ybAgF3pfIowlQVBylHQupjRU1wgppQKq DIWW7TrO5VhB0rKtm3w2KFRLEBkFXoerKKnPuvA1jADf/i+aPBDdHG23QOVqenCL5UA0sIVdrUVpI OeVvBmPjX7pFMDWtaHwV0rDLzi8U42QfBDZdvTmnEMaH8sJJnLoEtS4jES+I+SAnt/8XP79hm1bOa 0O8OUXIl6GYz7tLRVQwRwAz4Kuckl5RGRrVInW1SVk9ODW7GvL5AhNgQv821d+IMJGGO5OSKLH7zZ GP0DwVR6QPbfbcZOSjcg==; 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 1hvOIK-0006d5-3y; Wed, 07 Aug 2019 15:56:08 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1hvOI0-0006Nu-Jy for linux-arm-kernel@lists.infradead.org; Wed, 07 Aug 2019 15:55:50 +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 4E23B15A2; Wed, 7 Aug 2019 08:55:48 -0700 (PDT) Received: from capper-ampere.manchester.arm.com (capper-ampere.manchester.arm.com [10.32.98.74]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 2064A3F706; Wed, 7 Aug 2019 08:55:47 -0700 (PDT) From: Steve Capper To: linux-arm-kernel@lists.infradead.org Subject: [PATCH V5 02/12] arm64: mm: Flip kernel VA space Date: Wed, 7 Aug 2019 16:55:14 +0100 Message-Id: <20190807155524.5112-3-steve.capper@arm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190807155524.5112-1-steve.capper@arm.com> References: <20190807155524.5112-1-steve.capper@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190807_085548_741207_D0794FF8 X-CRM114-Status: GOOD ( 16.35 ) 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, catalin.marinas@arm.com, bhsharma@redhat.com, Steve Capper , maz@kernel.org, will@kernel.org 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 In order to allow for a KASAN shadow that changes size at boot time, one must fix the KASAN_SHADOW_END for both 48 & 52-bit VAs and "grow" the start address. Also, it is highly desirable to maintain the same function addresses in the kernel .text between VA sizes. Both of these requirements necessitate us to flip the kernel address space halves s.t. the direct linear map occupies the lower addresses. This patch puts the direct linear map in the lower addresses of the kernel VA range and everything else in the higher ranges. 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. As part of the re-arrangement, a guard region of 2MB (to preserve alignment for fixed map) is added after the vmemmap. Otherwise the vmemmap could intersect with IS_ERR pointers. Signed-off-by: Steve Capper Reviewed-by: Catalin Marinas --- Changed in V5 - simplify the kernel page table dumper patch as we have 2MB gap at the end of the kernel virtual address space. Changed in V4 - we add a guard region after vmemmap to avoid ambiguity with error pointers --- 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 | 5 +++-- arch/arm64/mm/init.c | 9 +-------- arch/arm64/mm/kasan_init.c | 6 +++--- arch/arm64/mm/mmu.c | 4 ++-- 8 files changed, 16 insertions(+), 22 deletions(-) diff --git a/arch/arm64/Makefile b/arch/arm64/Makefile index bb1f1dbb34e8..b2400f9c1213 100644 --- a/arch/arm64/Makefile +++ b/arch/arm64/Makefile @@ -130,7 +130,7 @@ 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 d3a951dc9878..98a87f0f40d5 100644 --- a/arch/arm64/include/asm/memory.h +++ b/arch/arm64/include/asm/memory.h @@ -38,9 +38,9 @@ */ #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) @@ -48,7 +48,7 @@ #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 - SZ_2M) #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) @@ -227,7 +227,7 @@ 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 3f5461f7b560..d274ea9a5f86 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -21,7 +21,7 @@ * 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 9341fcc6e809..e130db05d932 100644 --- a/arch/arm64/kernel/hibernate.c +++ b/arch/arm64/kernel/hibernate.c @@ -496,7 +496,7 @@ 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 82b3a7fdb4a6..beec87488e97 100644 --- a/arch/arm64/mm/dump.c +++ b/arch/arm64/mm/dump.c @@ -26,6 +26,8 @@ #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" }, @@ -42,7 +44,6 @@ static const struct addr_marker address_markers[] = { { VMEMMAP_START, "vmemmap start" }, { VMEMMAP_START + VMEMMAP_SIZE, "vmemmap end" }, #endif - { PAGE_OFFSET, "Linear mapping" }, { -1, NULL }, }; @@ -376,7 +377,7 @@ 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 f3c795278def..62927ed02229 100644 --- a/arch/arm64/mm/init.c +++ b/arch/arm64/mm/init.c @@ -301,7 +301,7 @@ 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(); @@ -309,13 +309,6 @@ 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 6cf97b904ebb..05edfe9b02e4 100644 --- a/arch/arm64/mm/kasan_init.c +++ b/arch/arm64/mm/kasan_init.c @@ -225,10 +225,10 @@ 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 750a69dde39b..1d4247f9a496 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -398,7 +398,7 @@ 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; @@ -425,7 +425,7 @@ 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;