From patchwork Thu Feb 25 08:04:51 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexandre Ghiti X-Patchwork-Id: 12103601 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=-16.8 required=3.0 tests=BAYES_00, 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 70AAEC433DB for ; Thu, 25 Feb 2021 08:06:27 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 77AD664EC8 for ; Thu, 25 Feb 2021 08:06:24 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 77AD664EC8 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ghiti.fr Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id DD0368D0008; Thu, 25 Feb 2021 03:06:23 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id D5A338D0005; Thu, 25 Feb 2021 03:06:23 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id BFA9B8D0008; Thu, 25 Feb 2021 03:06:23 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0060.hostedemail.com [216.40.44.60]) by kanga.kvack.org (Postfix) with ESMTP id A11A48D0005 for ; Thu, 25 Feb 2021 03:06:23 -0500 (EST) Received: from smtpin04.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 6E4458E5F for ; Thu, 25 Feb 2021 08:06:23 +0000 (UTC) X-FDA: 77856057846.04.60D5C84 Received: from relay11.mail.gandi.net (relay11.mail.gandi.net [217.70.178.231]) by imf13.hostedemail.com (Postfix) with ESMTP id 1FED5E0011E0 for ; Thu, 25 Feb 2021 08:06:19 +0000 (UTC) Received: from localhost.localdomain (35.161.185.81.rev.sfr.net [81.185.161.35]) (Authenticated sender: alex@ghiti.fr) by relay11.mail.gandi.net (Postfix) with ESMTPSA id AE3EC100003; Thu, 25 Feb 2021 08:06:13 +0000 (UTC) From: Alexandre Ghiti To: Jonathan Corbet , Paul Walmsley , Palmer Dabbelt , Albert Ou , Arnd Bergmann , Andrey Ryabinin , Alexander Potapenko , Dmitry Vyukov , linux-doc@vger.kernel.org, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com, linux-arch@vger.kernel.org, linux-mm@kvack.org Cc: Alexandre Ghiti Subject: [PATCH 1/3] riscv: Move kernel mapping outside of linear mapping Date: Thu, 25 Feb 2021 03:04:51 -0500 Message-Id: <20210225080453.1314-2-alex@ghiti.fr> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20210225080453.1314-1-alex@ghiti.fr> References: <20210225080453.1314-1-alex@ghiti.fr> MIME-Version: 1.0 X-Stat-Signature: uojijxx1pffimftuwm91aasuqj7nmtep X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 1FED5E0011E0 Received-SPF: none (ghiti.fr>: No applicable sender policy available) receiver=imf13; identity=mailfrom; envelope-from=""; helo=relay11.mail.gandi.net; client-ip=217.70.178.231 X-HE-DKIM-Result: none/none X-HE-Tag: 1614240379-694462 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: This is a preparatory patch for relocatable kernel and sv48 support. The kernel used to be linked at PAGE_OFFSET address therefore we could use the linear mapping for the kernel mapping. But the relocated kernel base address will be different from PAGE_OFFSET and since in the linear mapping, two different virtual addresses cannot point to the same physical address, the kernel mapping needs to lie outside the linear mapping so that we don't have to copy it at the same physical offset. The kernel mapping is moved to the last 2GB of the address space, BPF is now always after the kernel and modules use the 2GB memory range right before the kernel, so BPF and modules regions do not overlap. KASLR implementation will simply have to move the kernel in the last 2GB range and just take care of leaving enough space for BPF. In addition, by moving the kernel to the end of the address space, both sv39 and sv48 kernels will be exactly the same without needing to be relocated at runtime. Suggested-by: Arnd Bergmann Signed-off-by: Alexandre Ghiti --- arch/riscv/boot/loader.lds.S | 3 +- arch/riscv/include/asm/page.h | 18 ++++++- arch/riscv/include/asm/pgtable.h | 37 +++++++++---- arch/riscv/include/asm/set_memory.h | 1 + arch/riscv/kernel/head.S | 3 +- arch/riscv/kernel/module.c | 6 +-- arch/riscv/kernel/setup.c | 3 ++ arch/riscv/kernel/vmlinux.lds.S | 3 +- arch/riscv/mm/fault.c | 13 +++++ arch/riscv/mm/init.c | 81 +++++++++++++++++++++++------ arch/riscv/mm/kasan_init.c | 9 ++++ arch/riscv/mm/physaddr.c | 2 +- 12 files changed, 141 insertions(+), 38 deletions(-) diff --git a/arch/riscv/boot/loader.lds.S b/arch/riscv/boot/loader.lds.S index 47a5003c2e28..62d94696a19c 100644 --- a/arch/riscv/boot/loader.lds.S +++ b/arch/riscv/boot/loader.lds.S @@ -1,13 +1,14 @@ /* SPDX-License-Identifier: GPL-2.0 */ #include +#include OUTPUT_ARCH(riscv) ENTRY(_start) SECTIONS { - . = PAGE_OFFSET; + . = KERNEL_LINK_ADDR; .payload : { *(.payload) diff --git a/arch/riscv/include/asm/page.h b/arch/riscv/include/asm/page.h index e49d51b97bc1..6557535dc2da 100644 --- a/arch/riscv/include/asm/page.h +++ b/arch/riscv/include/asm/page.h @@ -90,15 +90,29 @@ typedef struct page *pgtable_t; #ifdef CONFIG_MMU extern unsigned long va_pa_offset; +extern unsigned long va_kernel_pa_offset; extern unsigned long pfn_base; #define ARCH_PFN_OFFSET (pfn_base) #else #define va_pa_offset 0 +#define va_kernel_pa_offset 0 #define ARCH_PFN_OFFSET (PAGE_OFFSET >> PAGE_SHIFT) #endif /* CONFIG_MMU */ -#define __pa_to_va_nodebug(x) ((void *)((unsigned long) (x) + va_pa_offset)) -#define __va_to_pa_nodebug(x) ((unsigned long)(x) - va_pa_offset) +extern unsigned long kernel_virt_addr; +extern uintptr_t load_pa, load_sz, load_sz_pmd; + +#define linear_mapping_pa_to_va(x) ((void *)((unsigned long)(x) + va_pa_offset)) +#define __pa_to_va_nodebug(x) linear_mapping_pa_to_va(x) + +#define linear_mapping_va_to_pa(x) ((unsigned long)(x) - va_pa_offset) +#define kernel_mapping_va_to_pa(x) \ + ((unsigned long)(x) - va_kernel_pa_offset) +#define __va_to_pa_nodebug(x) ({ \ + unsigned long _x = x; \ + (_x < kernel_virt_addr) ? \ + linear_mapping_va_to_pa(_x) : kernel_mapping_va_to_pa(_x); \ + }) #ifdef CONFIG_DEBUG_VIRTUAL extern phys_addr_t __virt_to_phys(unsigned long x); diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h index 25e90cf0bde4..50c068993591 100644 --- a/arch/riscv/include/asm/pgtable.h +++ b/arch/riscv/include/asm/pgtable.h @@ -11,23 +11,30 @@ #include -#ifndef __ASSEMBLY__ - -/* Page Upper Directory not used in RISC-V */ -#include -#include -#include -#include +#ifndef CONFIG_MMU +#define KERNEL_LINK_ADDR PAGE_OFFSET +#else -#ifdef CONFIG_MMU +#define ADDRESS_SPACE_END (UL(-1)) +/* + * Leave 2GB for kernel and BPF at the end of the address space + */ +#define KERNEL_LINK_ADDR (ADDRESS_SPACE_END - SZ_2G + 1) #define VMALLOC_SIZE (KERN_VIRT_SIZE >> 1) #define VMALLOC_END (PAGE_OFFSET - 1) #define VMALLOC_START (PAGE_OFFSET - VMALLOC_SIZE) +/* KASLR should leave at least 128MB for BPF after the kernel */ #define BPF_JIT_REGION_SIZE (SZ_128M) -#define BPF_JIT_REGION_START (PAGE_OFFSET - BPF_JIT_REGION_SIZE) -#define BPF_JIT_REGION_END (VMALLOC_END) +#define BPF_JIT_REGION_START PFN_ALIGN((unsigned long)&_end) +#define BPF_JIT_REGION_END (BPF_JIT_REGION_START + BPF_JIT_REGION_SIZE) + +/* Modules always live before the kernel */ +#ifdef CONFIG_64BIT +#define MODULES_VADDR (PFN_ALIGN((unsigned long)&_end) - SZ_2G) +#define MODULES_END (PFN_ALIGN((unsigned long)&_start)) +#endif /* * Roughly size the vmemmap space to be large enough to fit enough @@ -57,9 +64,16 @@ #define FIXADDR_SIZE PGDIR_SIZE #endif #define FIXADDR_START (FIXADDR_TOP - FIXADDR_SIZE) - #endif +#ifndef __ASSEMBLY__ + +/* Page Upper Directory not used in RISC-V */ +#include +#include +#include +#include + #ifdef CONFIG_64BIT #include #else @@ -485,6 +499,7 @@ static inline int ptep_clear_flush_young(struct vm_area_struct *vma, #define kern_addr_valid(addr) (1) /* FIXME */ +extern char _start[]; extern void *dtb_early_va; extern uintptr_t dtb_early_pa; void setup_bootmem(void); diff --git a/arch/riscv/include/asm/set_memory.h b/arch/riscv/include/asm/set_memory.h index 9fa510707012..03df05bc639a 100644 --- a/arch/riscv/include/asm/set_memory.h +++ b/arch/riscv/include/asm/set_memory.h @@ -17,6 +17,7 @@ int set_memory_x(unsigned long addr, int numpages); int set_memory_nx(unsigned long addr, int numpages); int set_memory_rw_nx(unsigned long addr, int numpages); void protect_kernel_text_data(void); +void protect_kernel_linear_mapping_text_rodata(void); #else static inline int set_memory_ro(unsigned long addr, int numpages) { return 0; } static inline int set_memory_rw(unsigned long addr, int numpages) { return 0; } diff --git a/arch/riscv/kernel/head.S b/arch/riscv/kernel/head.S index f5a9bad86e58..6cb05f22e52a 100644 --- a/arch/riscv/kernel/head.S +++ b/arch/riscv/kernel/head.S @@ -69,7 +69,8 @@ pe_head_start: #ifdef CONFIG_MMU relocate: /* Relocate return address */ - li a1, PAGE_OFFSET + la a1, kernel_virt_addr + REG_L a1, 0(a1) la a2, _start sub a1, a1, a2 add ra, ra, a1 diff --git a/arch/riscv/kernel/module.c b/arch/riscv/kernel/module.c index 104fba889cf7..ce153771e5e9 100644 --- a/arch/riscv/kernel/module.c +++ b/arch/riscv/kernel/module.c @@ -408,12 +408,10 @@ int apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab, } #if defined(CONFIG_MMU) && defined(CONFIG_64BIT) -#define VMALLOC_MODULE_START \ - max(PFN_ALIGN((unsigned long)&_end - SZ_2G), VMALLOC_START) void *module_alloc(unsigned long size) { - return __vmalloc_node_range(size, 1, VMALLOC_MODULE_START, - VMALLOC_END, GFP_KERNEL, + return __vmalloc_node_range(size, 1, MODULES_VADDR, + MODULES_END, GFP_KERNEL, PAGE_KERNEL_EXEC, 0, NUMA_NO_NODE, __builtin_return_address(0)); } diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c index 4945b5085241..c8ea6a72faf6 100644 --- a/arch/riscv/kernel/setup.c +++ b/arch/riscv/kernel/setup.c @@ -263,6 +263,9 @@ void __init setup_arch(char **cmdline_p) if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX)) protect_kernel_text_data(); + + protect_kernel_linear_mapping_text_rodata(); + #ifdef CONFIG_SWIOTLB swiotlb_init(1); #endif diff --git a/arch/riscv/kernel/vmlinux.lds.S b/arch/riscv/kernel/vmlinux.lds.S index de03cb22d0e9..0726c05e0336 100644 --- a/arch/riscv/kernel/vmlinux.lds.S +++ b/arch/riscv/kernel/vmlinux.lds.S @@ -4,7 +4,8 @@ * Copyright (C) 2017 SiFive */ -#define LOAD_OFFSET PAGE_OFFSET +#include +#define LOAD_OFFSET KERNEL_LINK_ADDR #include #include #include diff --git a/arch/riscv/mm/fault.c b/arch/riscv/mm/fault.c index 8f17519208c7..1b14d523a95c 100644 --- a/arch/riscv/mm/fault.c +++ b/arch/riscv/mm/fault.c @@ -231,6 +231,19 @@ asmlinkage void do_page_fault(struct pt_regs *regs) return; } +#ifdef CONFIG_64BIT + /* + * Modules in 64bit kernels lie in their own virtual region which is not + * in the vmalloc region, but dealing with page faults in this region + * or the vmalloc region amounts to doing the same thing: checking that + * the mapping exists in init_mm.pgd and updating user page table, so + * just use vmalloc_fault. + */ + if (unlikely(addr >= MODULES_VADDR && addr < MODULES_END)) { + vmalloc_fault(regs, code, addr); + return; + } +#endif /* Enable interrupts if they were enabled in the parent context. */ if (likely(regs->status & SR_PIE)) local_irq_enable(); diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c index 3e044f11cef6..18792937cf31 100644 --- a/arch/riscv/mm/init.c +++ b/arch/riscv/mm/init.c @@ -25,6 +25,9 @@ #include "../kernel/head.h" +unsigned long kernel_virt_addr = KERNEL_LINK_ADDR; +EXPORT_SYMBOL(kernel_virt_addr); + unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)] __page_aligned_bss; EXPORT_SYMBOL(empty_zero_page); @@ -88,6 +91,8 @@ static void print_vm_layout(void) (unsigned long)VMALLOC_END); print_mlm("lowmem", (unsigned long)PAGE_OFFSET, (unsigned long)high_memory); + print_mlm("kernel", (unsigned long)KERNEL_LINK_ADDR, + (unsigned long)ADDRESS_SPACE_END); } #else static void print_vm_layout(void) { } @@ -130,8 +135,13 @@ void __init setup_bootmem(void) */ memblock_enforce_memory_limit(-PAGE_OFFSET); - /* Reserve from the start of the kernel to the end of the kernel */ - memblock_reserve(vmlinux_start, vmlinux_end - vmlinux_start); + /* + * Reserve from the start of the kernel to the end of the kernel + * and make sure we align the reservation on PMD_SIZE since we will + * map the kernel in the linear mapping as read-only: we do not want + * any allocation to happen between _end and the next pmd aligned page. + */ + memblock_reserve(load_pa, load_sz_pmd); max_pfn = PFN_DOWN(memblock_end_of_DRAM()); max_low_pfn = max_pfn; @@ -156,8 +166,12 @@ void __init setup_bootmem(void) #ifdef CONFIG_MMU static struct pt_alloc_ops pt_ops; +/* Offset between linear mapping virtual address and kernel load address */ unsigned long va_pa_offset; EXPORT_SYMBOL(va_pa_offset); +/* Offset between kernel mapping virtual address and kernel load address */ +unsigned long va_kernel_pa_offset; +EXPORT_SYMBOL(va_kernel_pa_offset); unsigned long pfn_base; EXPORT_SYMBOL(pfn_base); @@ -261,7 +275,7 @@ static pmd_t *get_pmd_virt_late(phys_addr_t pa) static phys_addr_t __init alloc_pmd_early(uintptr_t va) { - BUG_ON((va - PAGE_OFFSET) >> PGDIR_SHIFT); + BUG_ON((va - kernel_virt_addr) >> PGDIR_SHIFT); return (uintptr_t)early_pmd; } @@ -376,17 +390,37 @@ static uintptr_t __init best_map_size(phys_addr_t base, phys_addr_t size) #error "setup_vm() is called from head.S before relocate so it should not use absolute addressing." #endif +uintptr_t load_pa, load_sz, load_sz_pmd; +EXPORT_SYMBOL(load_pa); +EXPORT_SYMBOL(load_sz); +EXPORT_SYMBOL(load_sz_pmd); + +static void __init create_kernel_page_table(pgd_t *pgdir, uintptr_t map_size) +{ + uintptr_t va, end_va; + + end_va = kernel_virt_addr + load_sz; + for (va = kernel_virt_addr; va < end_va; va += map_size) + create_pgd_mapping(pgdir, va, + load_pa + (va - kernel_virt_addr), + map_size, PAGE_KERNEL_EXEC); +} + asmlinkage void __init setup_vm(uintptr_t dtb_pa) { - uintptr_t va, pa, end_va; - uintptr_t load_pa = (uintptr_t)(&_start); - uintptr_t load_sz = (uintptr_t)(&_end) - load_pa; + uintptr_t pa; uintptr_t map_size; #ifndef __PAGETABLE_PMD_FOLDED pmd_t fix_bmap_spmd, fix_bmap_epmd; #endif + load_pa = (uintptr_t)(&_start); + load_sz = (uintptr_t)(&_end) - load_pa; + load_sz_pmd = (load_sz + PMD_SIZE - 1) & PMD_MASK; + va_pa_offset = PAGE_OFFSET - load_pa; + va_kernel_pa_offset = kernel_virt_addr - load_pa; + pfn_base = PFN_DOWN(load_pa); /* @@ -414,26 +448,22 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa) create_pmd_mapping(fixmap_pmd, FIXADDR_START, (uintptr_t)fixmap_pte, PMD_SIZE, PAGE_TABLE); /* Setup trampoline PGD and PMD */ - create_pgd_mapping(trampoline_pg_dir, PAGE_OFFSET, + create_pgd_mapping(trampoline_pg_dir, kernel_virt_addr, (uintptr_t)trampoline_pmd, PGDIR_SIZE, PAGE_TABLE); - create_pmd_mapping(trampoline_pmd, PAGE_OFFSET, + create_pmd_mapping(trampoline_pmd, kernel_virt_addr, load_pa, PMD_SIZE, PAGE_KERNEL_EXEC); #else /* Setup trampoline PGD */ - create_pgd_mapping(trampoline_pg_dir, PAGE_OFFSET, + create_pgd_mapping(trampoline_pg_dir, kernel_virt_addr, load_pa, PGDIR_SIZE, PAGE_KERNEL_EXEC); #endif /* - * Setup early PGD covering entire kernel which will allows + * Setup early PGD covering entire kernel which will allow * us to reach paging_init(). We map all memory banks later * in setup_vm_final() below. */ - end_va = PAGE_OFFSET + load_sz; - for (va = PAGE_OFFSET; va < end_va; va += map_size) - create_pgd_mapping(early_pg_dir, va, - load_pa + (va - PAGE_OFFSET), - map_size, PAGE_KERNEL_EXEC); + create_kernel_page_table(early_pg_dir, map_size); #ifndef __PAGETABLE_PMD_FOLDED /* Setup early PMD for DTB */ @@ -496,6 +526,20 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa) #endif } +void protect_kernel_linear_mapping_text_rodata(void) +{ + unsigned long text_start = (unsigned long)lm_alias(_start); + unsigned long init_text_start = (unsigned long)lm_alias(__init_text_begin); + unsigned long rodata_start = (unsigned long)lm_alias(__start_rodata); + unsigned long data_start = (unsigned long)lm_alias(_data); + + set_memory_ro(text_start, (init_text_start - text_start) >> PAGE_SHIFT); + set_memory_nx(text_start, (init_text_start - text_start) >> PAGE_SHIFT); + + set_memory_ro(rodata_start, (data_start - rodata_start) >> PAGE_SHIFT); + set_memory_nx(rodata_start, (data_start - rodata_start) >> PAGE_SHIFT); +} + static void __init setup_vm_final(void) { uintptr_t va, map_size; @@ -517,7 +561,7 @@ static void __init setup_vm_final(void) __pa_symbol(fixmap_pgd_next), PGDIR_SIZE, PAGE_TABLE); - /* Map all memory banks */ + /* Map all memory banks in the linear mapping */ for_each_mem_range(i, &start, &end) { if (start >= end) break; @@ -529,10 +573,13 @@ static void __init setup_vm_final(void) for (pa = start; pa < end; pa += map_size) { va = (uintptr_t)__va(pa); create_pgd_mapping(swapper_pg_dir, va, pa, - map_size, PAGE_KERNEL_EXEC); + map_size, PAGE_KERNEL); } } + /* Map the kernel */ + create_kernel_page_table(swapper_pg_dir, PMD_SIZE); + /* Clear fixmap PTE and PMD mappings */ clear_fixmap(FIX_PTE); clear_fixmap(FIX_PMD); diff --git a/arch/riscv/mm/kasan_init.c b/arch/riscv/mm/kasan_init.c index 171569df4334..89622785d500 100644 --- a/arch/riscv/mm/kasan_init.c +++ b/arch/riscv/mm/kasan_init.c @@ -172,6 +172,10 @@ void __init kasan_init(void) phys_addr_t _start, _end; u64 i; + /* + * Populate all kernel virtual address space with kasan_early_shadow_page + * except for the linear mapping and the modules/kernel/BPF mapping. + */ kasan_populate_early_shadow((void *)KASAN_SHADOW_START, (void *)kasan_mem_to_shadow((void *) VMEMMAP_END)); @@ -184,6 +188,7 @@ void __init kasan_init(void) (void *)kasan_mem_to_shadow((void *)VMALLOC_START), (void *)kasan_mem_to_shadow((void *)VMALLOC_END)); + /* Populate the linear mapping */ for_each_mem_range(i, &_start, &_end) { void *start = (void *)_start; void *end = (void *)_end; @@ -194,6 +199,10 @@ void __init kasan_init(void) kasan_populate(kasan_mem_to_shadow(start), kasan_mem_to_shadow(end)); }; + /* Populate kernel, BPF, modules mapping */ + kasan_populate(kasan_mem_to_shadow((const void *)MODULES_VADDR), + kasan_mem_to_shadow((const void *)BPF_JIT_REGION_END)); + for (i = 0; i < PTRS_PER_PTE; i++) set_pte(&kasan_early_shadow_pte[i], mk_pte(virt_to_page(kasan_early_shadow_page), diff --git a/arch/riscv/mm/physaddr.c b/arch/riscv/mm/physaddr.c index e8e4dcd39fed..35703d5ef5fd 100644 --- a/arch/riscv/mm/physaddr.c +++ b/arch/riscv/mm/physaddr.c @@ -23,7 +23,7 @@ EXPORT_SYMBOL(__virt_to_phys); phys_addr_t __phys_addr_symbol(unsigned long x) { - unsigned long kernel_start = (unsigned long)PAGE_OFFSET; + unsigned long kernel_start = (unsigned long)kernel_virt_addr; unsigned long kernel_end = (unsigned long)_end; /* From patchwork Thu Feb 25 08:04:52 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Alexandre Ghiti X-Patchwork-Id: 12103611 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=-16.8 required=3.0 tests=BAYES_00, 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 4C603C433DB for ; Thu, 25 Feb 2021 08:07:38 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 97AEA64EF1 for ; 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Thu, 25 Feb 2021 08:07:36 +0000 (UTC) X-FDA: 77856060912.03.ABF6883 Received: from relay5-d.mail.gandi.net (relay5-d.mail.gandi.net [217.70.183.197]) by imf18.hostedemail.com (Postfix) with ESMTP id 3EE8B2000395 for ; Thu, 25 Feb 2021 08:07:37 +0000 (UTC) X-Originating-IP: 81.185.161.35 Received: from localhost.localdomain (35.161.185.81.rev.sfr.net [81.185.161.35]) (Authenticated sender: alex@ghiti.fr) by relay5-d.mail.gandi.net (Postfix) with ESMTPSA id 8DAD41C0006; Thu, 25 Feb 2021 08:07:26 +0000 (UTC) From: Alexandre Ghiti To: Jonathan Corbet , Paul Walmsley , Palmer Dabbelt , Albert Ou , Arnd Bergmann , Andrey Ryabinin , Alexander Potapenko , Dmitry Vyukov , linux-doc@vger.kernel.org, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com, linux-arch@vger.kernel.org, linux-mm@kvack.org Cc: Alexandre Ghiti Subject: [PATCH 2/3] Documentation: riscv: Add documentation that describes the VM layout Date: Thu, 25 Feb 2021 03:04:52 -0500 Message-Id: <20210225080453.1314-3-alex@ghiti.fr> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20210225080453.1314-1-alex@ghiti.fr> References: <20210225080453.1314-1-alex@ghiti.fr> MIME-Version: 1.0 X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: 3EE8B2000395 X-Stat-Signature: g57f1nmo3eicx1c99zaschukirby3wqs Received-SPF: none (ghiti.fr>: No applicable sender policy available) receiver=imf18; identity=mailfrom; envelope-from=""; helo=relay5-d.mail.gandi.net; client-ip=217.70.183.197 X-HE-DKIM-Result: none/none X-HE-Tag: 1614240457-794273 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: This new document presents the RISC-V virtual memory layout and is based one the x86 one: it describes the different limits of the different regions of the virtual address space. Signed-off-by: Alexandre Ghiti --- Documentation/riscv/index.rst | 1 + Documentation/riscv/vm-layout.rst | 61 +++++++++++++++++++++++++++++++ 2 files changed, 62 insertions(+) create mode 100644 Documentation/riscv/vm-layout.rst diff --git a/Documentation/riscv/index.rst b/Documentation/riscv/index.rst index 6e6e39482502..ea915c196048 100644 --- a/Documentation/riscv/index.rst +++ b/Documentation/riscv/index.rst @@ -6,6 +6,7 @@ RISC-V architecture :maxdepth: 1 boot-image-header + vm-layout pmu patch-acceptance diff --git a/Documentation/riscv/vm-layout.rst b/Documentation/riscv/vm-layout.rst new file mode 100644 index 000000000000..e8e569e2686a --- /dev/null +++ b/Documentation/riscv/vm-layout.rst @@ -0,0 +1,61 @@ +===================================== +Virtual Memory Layout on RISC-V Linux +===================================== + +:Author: Alexandre Ghiti +:Date: 12 February 2021 + +This document describes the virtual memory layout used by the RISC-V Linux +Kernel. + +RISC-V Linux Kernel 32bit +========================= + +RISC-V Linux Kernel SV32 +------------------------ + +TODO + +RISC-V Linux Kernel 64bit +========================= + +The RISC-V privileged architecture document states that the 64bit addresses +"must have bits 63–48 all equal to bit 47, or else a page-fault exception will +occur.": that splits the virtual address space into 2 halves separated by a very +big hole, the lower half is where the userspace resides, the upper half is where +the RISC-V Linux Kernel resides. + +RISC-V Linux Kernel SV39 +------------------------ + +:: + + ======================================================================================================================== + Start addr | Offset | End addr | Size | VM area description + ======================================================================================================================== + | | | | + 0000000000000000 | 0 | 0000003fffffffff | 256 GB | user-space virtual memory, different per mm + __________________|____________|__________________|_________|___________________________________________________________ + | | | | + 0000004000000000 | +256 GB | ffffffbfffffffff | ~16M TB | ... huge, almost 64 bits wide hole of non-canonical + | | | | virtual memory addresses up to the -256 GB + | | | | starting offset of kernel mappings. + __________________|____________|__________________|_________|___________________________________________________________ + | + | Kernel-space virtual memory, shared between all processes: + ____________________________________________________________|___________________________________________________________ + | | | | + ffffffc000000000 | -256 GB | ffffffc7ffffffff | 32 GB | kasan + ffffffcefee00000 | -196 GB | ffffffcefeffffff | 2 MB | fixmap + ffffffceff000000 | -196 GB | ffffffceffffffff | 16 MB | PCI io + ffffffcf00000000 | -196 GB | ffffffcfffffffff | 4 GB | vmemmap + ffffffd000000000 | -192 GB | ffffffdfffffffff | 64 GB | vmalloc/ioremap space + ffffffe000000000 | -128 GB | ffffffff7fffffff | 126 GB | direct mapping of all physical memory + __________________|____________|__________________|_________|____________________________________________________________ + | + | + ____________________________________________________________|____________________________________________________________ + | | | | + ffffffff00000000 | -4 GB | ffffffff7fffffff | 2 GB | modules + ffffffff80000000 | -2 GB | ffffffffffffffff | 2 GB | kernel, BPF + __________________|____________|__________________|_________|____________________________________________________________ From patchwork Thu Feb 25 08:04:53 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexandre Ghiti X-Patchwork-Id: 12103613 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=-16.8 required=3.0 tests=BAYES_00, 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 86F9CC433E0 for ; Thu, 25 Feb 2021 08:08:45 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 092D964EBA for ; Thu, 25 Feb 2021 08:08:44 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 092D964EBA Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ghiti.fr Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 788728D000A; Thu, 25 Feb 2021 03:08:44 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 75F8C8D0005; Thu, 25 Feb 2021 03:08:44 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 65DA58D000A; Thu, 25 Feb 2021 03:08:44 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0085.hostedemail.com [216.40.44.85]) by kanga.kvack.org (Postfix) with ESMTP id 4FF6F8D0005 for ; Thu, 25 Feb 2021 03:08:44 -0500 (EST) Received: from smtpin20.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 15C3EEFF4 for ; Thu, 25 Feb 2021 08:08:44 +0000 (UTC) X-FDA: 77856063768.20.EB4A849 Received: from relay12.mail.gandi.net (relay12.mail.gandi.net [217.70.178.232]) by imf19.hostedemail.com (Postfix) with ESMTP id 5290190009EA for ; Thu, 25 Feb 2021 08:08:39 +0000 (UTC) Received: from localhost.localdomain (35.161.185.81.rev.sfr.net [81.185.161.35]) (Authenticated sender: alex@ghiti.fr) by relay12.mail.gandi.net (Postfix) with ESMTPSA id D4AB9200006; Thu, 25 Feb 2021 08:08:34 +0000 (UTC) From: Alexandre Ghiti To: Jonathan Corbet , Paul Walmsley , Palmer Dabbelt , Albert Ou , Arnd Bergmann , Andrey Ryabinin , Alexander Potapenko , Dmitry Vyukov , linux-doc@vger.kernel.org, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com, linux-arch@vger.kernel.org, linux-mm@kvack.org Cc: Alexandre Ghiti , Anup Patel Subject: [PATCH 3/3] riscv: Prepare ptdump for vm layout dynamic addresses Date: Thu, 25 Feb 2021 03:04:53 -0500 Message-Id: <20210225080453.1314-4-alex@ghiti.fr> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20210225080453.1314-1-alex@ghiti.fr> References: <20210225080453.1314-1-alex@ghiti.fr> MIME-Version: 1.0 X-Stat-Signature: zo9wzgaxu5es16tdyna8nqk5akx16p7x X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: 5290190009EA Received-SPF: none (ghiti.fr>: No applicable sender policy available) receiver=imf19; identity=mailfrom; envelope-from=""; helo=relay12.mail.gandi.net; client-ip=217.70.178.232 X-HE-DKIM-Result: none/none X-HE-Tag: 1614240519-313713 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: This is a preparatory patch for sv48 support that will introduce dynamic PAGE_OFFSET. Dynamic PAGE_OFFSET implies that all zones (vmalloc, vmemmap, fixaddr...) whose addresses depend on PAGE_OFFSET become dynamic and can't be used to statically initialize the array used by ptdump to identify the different zones of the vm layout. Signed-off-by: Alexandre Ghiti Reviewed-by: Anup Patel --- arch/riscv/mm/ptdump.c | 67 ++++++++++++++++++++++++++++++++++-------- 1 file changed, 55 insertions(+), 12 deletions(-) diff --git a/arch/riscv/mm/ptdump.c b/arch/riscv/mm/ptdump.c index ace74dec7492..aa1b3bce61ab 100644 --- a/arch/riscv/mm/ptdump.c +++ b/arch/riscv/mm/ptdump.c @@ -58,29 +58,52 @@ struct ptd_mm_info { unsigned long end; }; +enum address_markers_idx { +#ifdef CONFIG_KASAN + KASAN_SHADOW_START_NR, + KASAN_SHADOW_END_NR, +#endif + FIXMAP_START_NR, + FIXMAP_END_NR, + PCI_IO_START_NR, + PCI_IO_END_NR, +#ifdef CONFIG_SPARSEMEM_VMEMMAP + VMEMMAP_START_NR, + VMEMMAP_END_NR, +#endif + VMALLOC_START_NR, + VMALLOC_END_NR, + PAGE_OFFSET_NR, + MODULES_MAPPING_NR, + KERNEL_MAPPING_NR, + END_OF_SPACE_NR +}; + static struct addr_marker address_markers[] = { #ifdef CONFIG_KASAN - {KASAN_SHADOW_START, "Kasan shadow start"}, - {KASAN_SHADOW_END, "Kasan shadow end"}, + {0, "Kasan shadow start"}, + {0, "Kasan shadow end"}, #endif - {FIXADDR_START, "Fixmap start"}, - {FIXADDR_TOP, "Fixmap end"}, - {PCI_IO_START, "PCI I/O start"}, - {PCI_IO_END, "PCI I/O end"}, + {0, "Fixmap start"}, + {0, "Fixmap end"}, + {0, "PCI I/O start"}, + {0, "PCI I/O end"}, #ifdef CONFIG_SPARSEMEM_VMEMMAP - {VMEMMAP_START, "vmemmap start"}, - {VMEMMAP_END, "vmemmap end"}, + {0, "vmemmap start"}, + {0, "vmemmap end"}, #endif - {VMALLOC_START, "vmalloc() area"}, - {VMALLOC_END, "vmalloc() end"}, - {PAGE_OFFSET, "Linear mapping"}, + {0, "vmalloc() area"}, + {0, "vmalloc() end"}, + {0, "Linear mapping"}, + {0, "Modules mapping"}, + {0, "Kernel mapping (kernel, BPF)"}, {-1, NULL}, }; static struct ptd_mm_info kernel_ptd_info = { .mm = &init_mm, .markers = address_markers, - .base_addr = KERN_VIRT_START, + .base_addr = 0, .end = ULONG_MAX, }; @@ -335,6 +358,26 @@ static int ptdump_init(void) { unsigned int i, j; +#ifdef CONFIG_KASAN + address_markers[KASAN_SHADOW_START_NR].start_address = KASAN_SHADOW_START; + address_markers[KASAN_SHADOW_END_NR].start_address = KASAN_SHADOW_END; +#endif + address_markers[FIXMAP_START_NR].start_address = FIXADDR_START; + address_markers[FIXMAP_END_NR].start_address = FIXADDR_TOP; + address_markers[PCI_IO_START_NR].start_address = PCI_IO_START; + address_markers[PCI_IO_END_NR].start_address = PCI_IO_END; +#ifdef CONFIG_SPARSEMEM_VMEMMAP + address_markers[VMEMMAP_START_NR].start_address = VMEMMAP_START; + address_markers[VMEMMAP_END_NR].start_address = VMEMMAP_END; +#endif + address_markers[VMALLOC_START_NR].start_address = VMALLOC_START; + address_markers[VMALLOC_END_NR].start_address = VMALLOC_END; + address_markers[PAGE_OFFSET_NR].start_address = PAGE_OFFSET; + address_markers[MODULES_MAPPING_NR].start_address = MODULES_VADDR; + address_markers[KERNEL_MAPPING_NR].start_address = kernel_virt_addr; + + kernel_ptd_info.base_addr = KERN_VIRT_START; + for (i = 0; i < ARRAY_SIZE(pg_level); i++) for (j = 0; j < ARRAY_SIZE(pte_bits); j++) pg_level[i].mask |= pte_bits[j].mask;