From: Andrey Konovalov <andreyknvl@xxxxxxxxxx> Subject: kasan: rename source files to reflect the new naming scheme We now have two KASAN modes: generic KASAN and tag-based KASAN. Rename kasan.c to generic.c to reflect that. Also rename kasan_init.c to init.c as it contains initialization code for both KASAN modes. Link: http://lkml.kernel.org/r/88c6fd2a883e459e6242030497230e5fb0d44d44.1544099024.git.andreyknvl@xxxxxxxxxx Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx> Reviewed-by: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx> Reviewed-by: Dmitry Vyukov <dvyukov@xxxxxxxxxx> Cc: Christoph Lameter <cl@xxxxxxxxx> Cc: Mark Rutland <mark.rutland@xxxxxxx> Cc: Will Deacon <will.deacon@xxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- --- /dev/null +++ a/mm/kasan/generic.c @@ -0,0 +1,343 @@ +/* + * This file contains core KASAN code. + * + * Copyright (c) 2014 Samsung Electronics Co., Ltd. + * Author: Andrey Ryabinin <ryabinin.a.a@xxxxxxxxx> + * + * Some code borrowed from https://github.com/xairy/kasan-prototype by + * Andrey Konovalov <andreyknvl@xxxxxxxxx> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt +#define DISABLE_BRANCH_PROFILING + +#include <linux/export.h> +#include <linux/interrupt.h> +#include <linux/init.h> +#include <linux/kasan.h> +#include <linux/kernel.h> +#include <linux/kmemleak.h> +#include <linux/linkage.h> +#include <linux/memblock.h> +#include <linux/memory.h> +#include <linux/mm.h> +#include <linux/module.h> +#include <linux/printk.h> +#include <linux/sched.h> +#include <linux/sched/task_stack.h> +#include <linux/slab.h> +#include <linux/stacktrace.h> +#include <linux/string.h> +#include <linux/types.h> +#include <linux/vmalloc.h> +#include <linux/bug.h> + +#include "kasan.h" +#include "../slab.h" + +/* + * All functions below always inlined so compiler could + * perform better optimizations in each of __asan_loadX/__assn_storeX + * depending on memory access size X. + */ + +static __always_inline bool memory_is_poisoned_1(unsigned long addr) +{ + s8 shadow_value = *(s8 *)kasan_mem_to_shadow((void *)addr); + + if (unlikely(shadow_value)) { + s8 last_accessible_byte = addr & KASAN_SHADOW_MASK; + return unlikely(last_accessible_byte >= shadow_value); + } + + return false; +} + +static __always_inline bool memory_is_poisoned_2_4_8(unsigned long addr, + unsigned long size) +{ + u8 *shadow_addr = (u8 *)kasan_mem_to_shadow((void *)addr); + + /* + * Access crosses 8(shadow size)-byte boundary. Such access maps + * into 2 shadow bytes, so we need to check them both. + */ + if (unlikely(((addr + size - 1) & KASAN_SHADOW_MASK) < size - 1)) + return *shadow_addr || memory_is_poisoned_1(addr + size - 1); + + return memory_is_poisoned_1(addr + size - 1); +} + +static __always_inline bool memory_is_poisoned_16(unsigned long addr) +{ + u16 *shadow_addr = (u16 *)kasan_mem_to_shadow((void *)addr); + + /* Unaligned 16-bytes access maps into 3 shadow bytes. */ + if (unlikely(!IS_ALIGNED(addr, KASAN_SHADOW_SCALE_SIZE))) + return *shadow_addr || memory_is_poisoned_1(addr + 15); + + return *shadow_addr; +} + +static __always_inline unsigned long bytes_is_nonzero(const u8 *start, + size_t size) +{ + while (size) { + if (unlikely(*start)) + return (unsigned long)start; + start++; + size--; + } + + return 0; +} + +static __always_inline unsigned long memory_is_nonzero(const void *start, + const void *end) +{ + unsigned int words; + unsigned long ret; + unsigned int prefix = (unsigned long)start % 8; + + if (end - start <= 16) + return bytes_is_nonzero(start, end - start); + + if (prefix) { + prefix = 8 - prefix; + ret = bytes_is_nonzero(start, prefix); + if (unlikely(ret)) + return ret; + start += prefix; + } + + words = (end - start) / 8; + while (words) { + if (unlikely(*(u64 *)start)) + return bytes_is_nonzero(start, 8); + start += 8; + words--; + } + + return bytes_is_nonzero(start, (end - start) % 8); +} + +static __always_inline bool memory_is_poisoned_n(unsigned long addr, + size_t size) +{ + unsigned long ret; + + ret = memory_is_nonzero(kasan_mem_to_shadow((void *)addr), + kasan_mem_to_shadow((void *)addr + size - 1) + 1); + + if (unlikely(ret)) { + unsigned long last_byte = addr + size - 1; + s8 *last_shadow = (s8 *)kasan_mem_to_shadow((void *)last_byte); + + if (unlikely(ret != (unsigned long)last_shadow || + ((long)(last_byte & KASAN_SHADOW_MASK) >= *last_shadow))) + return true; + } + return false; +} + +static __always_inline bool memory_is_poisoned(unsigned long addr, size_t size) +{ + if (__builtin_constant_p(size)) { + switch (size) { + case 1: + return memory_is_poisoned_1(addr); + case 2: + case 4: + case 8: + return memory_is_poisoned_2_4_8(addr, size); + case 16: + return memory_is_poisoned_16(addr); + default: + BUILD_BUG(); + } + } + + return memory_is_poisoned_n(addr, size); +} + +static __always_inline void check_memory_region_inline(unsigned long addr, + size_t size, bool write, + unsigned long ret_ip) +{ + if (unlikely(size == 0)) + return; + + if (unlikely((void *)addr < + kasan_shadow_to_mem((void *)KASAN_SHADOW_START))) { + kasan_report(addr, size, write, ret_ip); + return; + } + + if (likely(!memory_is_poisoned(addr, size))) + return; + + kasan_report(addr, size, write, ret_ip); +} + +void check_memory_region(unsigned long addr, size_t size, bool write, + unsigned long ret_ip) +{ + check_memory_region_inline(addr, size, write, ret_ip); +} + +void kasan_cache_shrink(struct kmem_cache *cache) +{ + quarantine_remove_cache(cache); +} + +void kasan_cache_shutdown(struct kmem_cache *cache) +{ + if (!__kmem_cache_empty(cache)) + quarantine_remove_cache(cache); +} + +static void register_global(struct kasan_global *global) +{ + size_t aligned_size = round_up(global->size, KASAN_SHADOW_SCALE_SIZE); + + kasan_unpoison_shadow(global->beg, global->size); + + kasan_poison_shadow(global->beg + aligned_size, + global->size_with_redzone - aligned_size, + KASAN_GLOBAL_REDZONE); +} + +void __asan_register_globals(struct kasan_global *globals, size_t size) +{ + int i; + + for (i = 0; i < size; i++) + register_global(&globals[i]); +} +EXPORT_SYMBOL(__asan_register_globals); + +void __asan_unregister_globals(struct kasan_global *globals, size_t size) +{ +} +EXPORT_SYMBOL(__asan_unregister_globals); + +#define DEFINE_ASAN_LOAD_STORE(size) \ + void __asan_load##size(unsigned long addr) \ + { \ + check_memory_region_inline(addr, size, false, _RET_IP_);\ + } \ + EXPORT_SYMBOL(__asan_load##size); \ + __alias(__asan_load##size) \ + void __asan_load##size##_noabort(unsigned long); \ + EXPORT_SYMBOL(__asan_load##size##_noabort); \ + void __asan_store##size(unsigned long addr) \ + { \ + check_memory_region_inline(addr, size, true, _RET_IP_); \ + } \ + EXPORT_SYMBOL(__asan_store##size); \ + __alias(__asan_store##size) \ + void __asan_store##size##_noabort(unsigned long); \ + EXPORT_SYMBOL(__asan_store##size##_noabort) + +DEFINE_ASAN_LOAD_STORE(1); +DEFINE_ASAN_LOAD_STORE(2); +DEFINE_ASAN_LOAD_STORE(4); +DEFINE_ASAN_LOAD_STORE(8); +DEFINE_ASAN_LOAD_STORE(16); + +void __asan_loadN(unsigned long addr, size_t size) +{ + check_memory_region(addr, size, false, _RET_IP_); +} +EXPORT_SYMBOL(__asan_loadN); + +__alias(__asan_loadN) +void __asan_loadN_noabort(unsigned long, size_t); +EXPORT_SYMBOL(__asan_loadN_noabort); + +void __asan_storeN(unsigned long addr, size_t size) +{ + check_memory_region(addr, size, true, _RET_IP_); +} +EXPORT_SYMBOL(__asan_storeN); + +__alias(__asan_storeN) +void __asan_storeN_noabort(unsigned long, size_t); +EXPORT_SYMBOL(__asan_storeN_noabort); + +/* to shut up compiler complaints */ +void __asan_handle_no_return(void) {} +EXPORT_SYMBOL(__asan_handle_no_return); + +/* Emitted by compiler to poison large objects when they go out of scope. */ +void __asan_poison_stack_memory(const void *addr, size_t size) +{ + /* + * Addr is KASAN_SHADOW_SCALE_SIZE-aligned and the object is surrounded + * by redzones, so we simply round up size to simplify logic. + */ + kasan_poison_shadow(addr, round_up(size, KASAN_SHADOW_SCALE_SIZE), + KASAN_USE_AFTER_SCOPE); +} +EXPORT_SYMBOL(__asan_poison_stack_memory); + +/* Emitted by compiler to unpoison large objects when they go into scope. */ +void __asan_unpoison_stack_memory(const void *addr, size_t size) +{ + kasan_unpoison_shadow(addr, size); +} +EXPORT_SYMBOL(__asan_unpoison_stack_memory); + +/* Emitted by compiler to poison alloca()ed objects. */ +void __asan_alloca_poison(unsigned long addr, size_t size) +{ + size_t rounded_up_size = round_up(size, KASAN_SHADOW_SCALE_SIZE); + size_t padding_size = round_up(size, KASAN_ALLOCA_REDZONE_SIZE) - + rounded_up_size; + size_t rounded_down_size = round_down(size, KASAN_SHADOW_SCALE_SIZE); + + const void *left_redzone = (const void *)(addr - + KASAN_ALLOCA_REDZONE_SIZE); + const void *right_redzone = (const void *)(addr + rounded_up_size); + + WARN_ON(!IS_ALIGNED(addr, KASAN_ALLOCA_REDZONE_SIZE)); + + kasan_unpoison_shadow((const void *)(addr + rounded_down_size), + size - rounded_down_size); + kasan_poison_shadow(left_redzone, KASAN_ALLOCA_REDZONE_SIZE, + KASAN_ALLOCA_LEFT); + kasan_poison_shadow(right_redzone, + padding_size + KASAN_ALLOCA_REDZONE_SIZE, + KASAN_ALLOCA_RIGHT); +} +EXPORT_SYMBOL(__asan_alloca_poison); + +/* Emitted by compiler to unpoison alloca()ed areas when the stack unwinds. */ +void __asan_allocas_unpoison(const void *stack_top, const void *stack_bottom) +{ + if (unlikely(!stack_top || stack_top > stack_bottom)) + return; + + kasan_unpoison_shadow(stack_top, stack_bottom - stack_top); +} +EXPORT_SYMBOL(__asan_allocas_unpoison); + +/* Emitted by the compiler to [un]poison local variables. */ +#define DEFINE_ASAN_SET_SHADOW(byte) \ + void __asan_set_shadow_##byte(const void *addr, size_t size) \ + { \ + __memset((void *)addr, 0x##byte, size); \ + } \ + EXPORT_SYMBOL(__asan_set_shadow_##byte) + +DEFINE_ASAN_SET_SHADOW(00); +DEFINE_ASAN_SET_SHADOW(f1); +DEFINE_ASAN_SET_SHADOW(f2); +DEFINE_ASAN_SET_SHADOW(f3); +DEFINE_ASAN_SET_SHADOW(f5); +DEFINE_ASAN_SET_SHADOW(f8); --- /dev/null +++ a/mm/kasan/init.c @@ -0,0 +1,488 @@ +/* + * This file contains some kasan initialization code. + * + * Copyright (c) 2015 Samsung Electronics Co., Ltd. + * Author: Andrey Ryabinin <ryabinin.a.a@xxxxxxxxx> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + */ + +#include <linux/memblock.h> +#include <linux/init.h> +#include <linux/kasan.h> +#include <linux/kernel.h> +#include <linux/mm.h> +#include <linux/pfn.h> +#include <linux/slab.h> + +#include <asm/page.h> +#include <asm/pgalloc.h> + +#include "kasan.h" + +/* + * This page serves two purposes: + * - It used as early shadow memory. The entire shadow region populated + * with this page, before we will be able to setup normal shadow memory. + * - Latter it reused it as zero shadow to cover large ranges of memory + * that allowed to access, but not handled by kasan (vmalloc/vmemmap ...). + */ +unsigned char kasan_zero_page[PAGE_SIZE] __page_aligned_bss; + +#if CONFIG_PGTABLE_LEVELS > 4 +p4d_t kasan_zero_p4d[MAX_PTRS_PER_P4D] __page_aligned_bss; +static inline bool kasan_p4d_table(pgd_t pgd) +{ + return pgd_page(pgd) == virt_to_page(lm_alias(kasan_zero_p4d)); +} +#else +static inline bool kasan_p4d_table(pgd_t pgd) +{ + return 0; +} +#endif +#if CONFIG_PGTABLE_LEVELS > 3 +pud_t kasan_zero_pud[PTRS_PER_PUD] __page_aligned_bss; +static inline bool kasan_pud_table(p4d_t p4d) +{ + return p4d_page(p4d) == virt_to_page(lm_alias(kasan_zero_pud)); +} +#else +static inline bool kasan_pud_table(p4d_t p4d) +{ + return 0; +} +#endif +#if CONFIG_PGTABLE_LEVELS > 2 +pmd_t kasan_zero_pmd[PTRS_PER_PMD] __page_aligned_bss; +static inline bool kasan_pmd_table(pud_t pud) +{ + return pud_page(pud) == virt_to_page(lm_alias(kasan_zero_pmd)); +} +#else +static inline bool kasan_pmd_table(pud_t pud) +{ + return 0; +} +#endif +pte_t kasan_zero_pte[PTRS_PER_PTE] __page_aligned_bss; + +static inline bool kasan_pte_table(pmd_t pmd) +{ + return pmd_page(pmd) == virt_to_page(lm_alias(kasan_zero_pte)); +} + +static inline bool kasan_zero_page_entry(pte_t pte) +{ + return pte_page(pte) == virt_to_page(lm_alias(kasan_zero_page)); +} + +static __init void *early_alloc(size_t size, int node) +{ + return memblock_alloc_try_nid(size, size, __pa(MAX_DMA_ADDRESS), + MEMBLOCK_ALLOC_ACCESSIBLE, node); +} + +static void __ref zero_pte_populate(pmd_t *pmd, unsigned long addr, + unsigned long end) +{ + pte_t *pte = pte_offset_kernel(pmd, addr); + pte_t zero_pte; + + zero_pte = pfn_pte(PFN_DOWN(__pa_symbol(kasan_zero_page)), PAGE_KERNEL); + zero_pte = pte_wrprotect(zero_pte); + + while (addr + PAGE_SIZE <= end) { + set_pte_at(&init_mm, addr, pte, zero_pte); + addr += PAGE_SIZE; + pte = pte_offset_kernel(pmd, addr); + } +} + +static int __ref zero_pmd_populate(pud_t *pud, unsigned long addr, + unsigned long end) +{ + pmd_t *pmd = pmd_offset(pud, addr); + unsigned long next; + + do { + next = pmd_addr_end(addr, end); + + if (IS_ALIGNED(addr, PMD_SIZE) && end - addr >= PMD_SIZE) { + pmd_populate_kernel(&init_mm, pmd, lm_alias(kasan_zero_pte)); + continue; + } + + if (pmd_none(*pmd)) { + pte_t *p; + + if (slab_is_available()) + p = pte_alloc_one_kernel(&init_mm, addr); + else + p = early_alloc(PAGE_SIZE, NUMA_NO_NODE); + if (!p) + return -ENOMEM; + + pmd_populate_kernel(&init_mm, pmd, p); + } + zero_pte_populate(pmd, addr, next); + } while (pmd++, addr = next, addr != end); + + return 0; +} + +static int __ref zero_pud_populate(p4d_t *p4d, unsigned long addr, + unsigned long end) +{ + pud_t *pud = pud_offset(p4d, addr); + unsigned long next; + + do { + next = pud_addr_end(addr, end); + if (IS_ALIGNED(addr, PUD_SIZE) && end - addr >= PUD_SIZE) { + pmd_t *pmd; + + pud_populate(&init_mm, pud, lm_alias(kasan_zero_pmd)); + pmd = pmd_offset(pud, addr); + pmd_populate_kernel(&init_mm, pmd, lm_alias(kasan_zero_pte)); + continue; + } + + if (pud_none(*pud)) { + pmd_t *p; + + if (slab_is_available()) { + p = pmd_alloc(&init_mm, pud, addr); + if (!p) + return -ENOMEM; + } else { + pud_populate(&init_mm, pud, + early_alloc(PAGE_SIZE, NUMA_NO_NODE)); + } + } + zero_pmd_populate(pud, addr, next); + } while (pud++, addr = next, addr != end); + + return 0; +} + +static int __ref zero_p4d_populate(pgd_t *pgd, unsigned long addr, + unsigned long end) +{ + p4d_t *p4d = p4d_offset(pgd, addr); + unsigned long next; + + do { + next = p4d_addr_end(addr, end); + if (IS_ALIGNED(addr, P4D_SIZE) && end - addr >= P4D_SIZE) { + pud_t *pud; + pmd_t *pmd; + + p4d_populate(&init_mm, p4d, lm_alias(kasan_zero_pud)); + pud = pud_offset(p4d, addr); + pud_populate(&init_mm, pud, lm_alias(kasan_zero_pmd)); + pmd = pmd_offset(pud, addr); + pmd_populate_kernel(&init_mm, pmd, + lm_alias(kasan_zero_pte)); + continue; + } + + if (p4d_none(*p4d)) { + pud_t *p; + + if (slab_is_available()) { + p = pud_alloc(&init_mm, p4d, addr); + if (!p) + return -ENOMEM; + } else { + p4d_populate(&init_mm, p4d, + early_alloc(PAGE_SIZE, NUMA_NO_NODE)); + } + } + zero_pud_populate(p4d, addr, next); + } while (p4d++, addr = next, addr != end); + + return 0; +} + +/** + * kasan_populate_zero_shadow - populate shadow memory region with + * kasan_zero_page + * @shadow_start - start of the memory range to populate + * @shadow_end - end of the memory range to populate + */ +int __ref kasan_populate_zero_shadow(const void *shadow_start, + const void *shadow_end) +{ + unsigned long addr = (unsigned long)shadow_start; + unsigned long end = (unsigned long)shadow_end; + pgd_t *pgd = pgd_offset_k(addr); + unsigned long next; + + do { + next = pgd_addr_end(addr, end); + + if (IS_ALIGNED(addr, PGDIR_SIZE) && end - addr >= PGDIR_SIZE) { + p4d_t *p4d; + pud_t *pud; + pmd_t *pmd; + + /* + * kasan_zero_pud should be populated with pmds + * at this moment. + * [pud,pmd]_populate*() below needed only for + * 3,2 - level page tables where we don't have + * puds,pmds, so pgd_populate(), pud_populate() + * is noops. + * + * The ifndef is required to avoid build breakage. + * + * With 5level-fixup.h, pgd_populate() is not nop and + * we reference kasan_zero_p4d. It's not defined + * unless 5-level paging enabled. + * + * The ifndef can be dropped once all KASAN-enabled + * architectures will switch to pgtable-nop4d.h. + */ +#ifndef __ARCH_HAS_5LEVEL_HACK + pgd_populate(&init_mm, pgd, lm_alias(kasan_zero_p4d)); +#endif + p4d = p4d_offset(pgd, addr); + p4d_populate(&init_mm, p4d, lm_alias(kasan_zero_pud)); + pud = pud_offset(p4d, addr); + pud_populate(&init_mm, pud, lm_alias(kasan_zero_pmd)); + pmd = pmd_offset(pud, addr); + pmd_populate_kernel(&init_mm, pmd, lm_alias(kasan_zero_pte)); + continue; + } + + if (pgd_none(*pgd)) { + p4d_t *p; + + if (slab_is_available()) { + p = p4d_alloc(&init_mm, pgd, addr); + if (!p) + return -ENOMEM; + } else { + pgd_populate(&init_mm, pgd, + early_alloc(PAGE_SIZE, NUMA_NO_NODE)); + } + } + zero_p4d_populate(pgd, addr, next); + } while (pgd++, addr = next, addr != end); + + return 0; +} + +static void kasan_free_pte(pte_t *pte_start, pmd_t *pmd) +{ + pte_t *pte; + int i; + + for (i = 0; i < PTRS_PER_PTE; i++) { + pte = pte_start + i; + if (!pte_none(*pte)) + return; + } + + pte_free_kernel(&init_mm, (pte_t *)page_to_virt(pmd_page(*pmd))); + pmd_clear(pmd); +} + +static void kasan_free_pmd(pmd_t *pmd_start, pud_t *pud) +{ + pmd_t *pmd; + int i; + + for (i = 0; i < PTRS_PER_PMD; i++) { + pmd = pmd_start + i; + if (!pmd_none(*pmd)) + return; + } + + pmd_free(&init_mm, (pmd_t *)page_to_virt(pud_page(*pud))); + pud_clear(pud); +} + +static void kasan_free_pud(pud_t *pud_start, p4d_t *p4d) +{ + pud_t *pud; + int i; + + for (i = 0; i < PTRS_PER_PUD; i++) { + pud = pud_start + i; + if (!pud_none(*pud)) + return; + } + + pud_free(&init_mm, (pud_t *)page_to_virt(p4d_page(*p4d))); + p4d_clear(p4d); +} + +static void kasan_free_p4d(p4d_t *p4d_start, pgd_t *pgd) +{ + p4d_t *p4d; + int i; + + for (i = 0; i < PTRS_PER_P4D; i++) { + p4d = p4d_start + i; + if (!p4d_none(*p4d)) + return; + } + + p4d_free(&init_mm, (p4d_t *)page_to_virt(pgd_page(*pgd))); + pgd_clear(pgd); +} + +static void kasan_remove_pte_table(pte_t *pte, unsigned long addr, + unsigned long end) +{ + unsigned long next; + + for (; addr < end; addr = next, pte++) { + next = (addr + PAGE_SIZE) & PAGE_MASK; + if (next > end) + next = end; + + if (!pte_present(*pte)) + continue; + + if (WARN_ON(!kasan_zero_page_entry(*pte))) + continue; + pte_clear(&init_mm, addr, pte); + } +} + +static void kasan_remove_pmd_table(pmd_t *pmd, unsigned long addr, + unsigned long end) +{ + unsigned long next; + + for (; addr < end; addr = next, pmd++) { + pte_t *pte; + + next = pmd_addr_end(addr, end); + + if (!pmd_present(*pmd)) + continue; + + if (kasan_pte_table(*pmd)) { + if (IS_ALIGNED(addr, PMD_SIZE) && + IS_ALIGNED(next, PMD_SIZE)) + pmd_clear(pmd); + continue; + } + pte = pte_offset_kernel(pmd, addr); + kasan_remove_pte_table(pte, addr, next); + kasan_free_pte(pte_offset_kernel(pmd, 0), pmd); + } +} + +static void kasan_remove_pud_table(pud_t *pud, unsigned long addr, + unsigned long end) +{ + unsigned long next; + + for (; addr < end; addr = next, pud++) { + pmd_t *pmd, *pmd_base; + + next = pud_addr_end(addr, end); + + if (!pud_present(*pud)) + continue; + + if (kasan_pmd_table(*pud)) { + if (IS_ALIGNED(addr, PUD_SIZE) && + IS_ALIGNED(next, PUD_SIZE)) + pud_clear(pud); + continue; + } + pmd = pmd_offset(pud, addr); + pmd_base = pmd_offset(pud, 0); + kasan_remove_pmd_table(pmd, addr, next); + kasan_free_pmd(pmd_base, pud); + } +} + +static void kasan_remove_p4d_table(p4d_t *p4d, unsigned long addr, + unsigned long end) +{ + unsigned long next; + + for (; addr < end; addr = next, p4d++) { + pud_t *pud; + + next = p4d_addr_end(addr, end); + + if (!p4d_present(*p4d)) + continue; + + if (kasan_pud_table(*p4d)) { + if (IS_ALIGNED(addr, P4D_SIZE) && + IS_ALIGNED(next, P4D_SIZE)) + p4d_clear(p4d); + continue; + } + pud = pud_offset(p4d, addr); + kasan_remove_pud_table(pud, addr, next); + kasan_free_pud(pud_offset(p4d, 0), p4d); + } +} + +void kasan_remove_zero_shadow(void *start, unsigned long size) +{ + unsigned long addr, end, next; + pgd_t *pgd; + + addr = (unsigned long)kasan_mem_to_shadow(start); + end = addr + (size >> KASAN_SHADOW_SCALE_SHIFT); + + if (WARN_ON((unsigned long)start % + (KASAN_SHADOW_SCALE_SIZE * PAGE_SIZE)) || + WARN_ON(size % (KASAN_SHADOW_SCALE_SIZE * PAGE_SIZE))) + return; + + for (; addr < end; addr = next) { + p4d_t *p4d; + + next = pgd_addr_end(addr, end); + + pgd = pgd_offset_k(addr); + if (!pgd_present(*pgd)) + continue; + + if (kasan_p4d_table(*pgd)) { + if (IS_ALIGNED(addr, PGDIR_SIZE) && + IS_ALIGNED(next, PGDIR_SIZE)) + pgd_clear(pgd); + continue; + } + + p4d = p4d_offset(pgd, addr); + kasan_remove_p4d_table(p4d, addr, next); + kasan_free_p4d(p4d_offset(pgd, 0), pgd); + } +} + +int kasan_add_zero_shadow(void *start, unsigned long size) +{ + int ret; + void *shadow_start, *shadow_end; + + shadow_start = kasan_mem_to_shadow(start); + shadow_end = shadow_start + (size >> KASAN_SHADOW_SCALE_SHIFT); + + if (WARN_ON((unsigned long)start % + (KASAN_SHADOW_SCALE_SIZE * PAGE_SIZE)) || + WARN_ON(size % (KASAN_SHADOW_SCALE_SIZE * PAGE_SIZE))) + return -EINVAL; + + ret = kasan_populate_zero_shadow(shadow_start, shadow_end); + if (ret) + kasan_remove_zero_shadow(shadow_start, + size >> KASAN_SHADOW_SCALE_SHIFT); + return ret; +} --- a/mm/kasan/kasan.c +++ /dev/null @@ -1,343 +0,0 @@ -/* - * This file contains core KASAN code. - * - * Copyright (c) 2014 Samsung Electronics Co., Ltd. - * Author: Andrey Ryabinin <ryabinin.a.a@xxxxxxxxx> - * - * Some code borrowed from https://github.com/xairy/kasan-prototype by - * Andrey Konovalov <andreyknvl@xxxxxxxxx> - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License version 2 as - * published by the Free Software Foundation. - * - */ - -#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt -#define DISABLE_BRANCH_PROFILING - -#include <linux/export.h> -#include <linux/interrupt.h> -#include <linux/init.h> -#include <linux/kasan.h> -#include <linux/kernel.h> -#include <linux/kmemleak.h> -#include <linux/linkage.h> -#include <linux/memblock.h> -#include <linux/memory.h> -#include <linux/mm.h> -#include <linux/module.h> -#include <linux/printk.h> -#include <linux/sched.h> -#include <linux/sched/task_stack.h> -#include <linux/slab.h> -#include <linux/stacktrace.h> -#include <linux/string.h> -#include <linux/types.h> -#include <linux/vmalloc.h> -#include <linux/bug.h> - -#include "kasan.h" -#include "../slab.h" - -/* - * All functions below always inlined so compiler could - * perform better optimizations in each of __asan_loadX/__assn_storeX - * depending on memory access size X. - */ - -static __always_inline bool memory_is_poisoned_1(unsigned long addr) -{ - s8 shadow_value = *(s8 *)kasan_mem_to_shadow((void *)addr); - - if (unlikely(shadow_value)) { - s8 last_accessible_byte = addr & KASAN_SHADOW_MASK; - return unlikely(last_accessible_byte >= shadow_value); - } - - return false; -} - -static __always_inline bool memory_is_poisoned_2_4_8(unsigned long addr, - unsigned long size) -{ - u8 *shadow_addr = (u8 *)kasan_mem_to_shadow((void *)addr); - - /* - * Access crosses 8(shadow size)-byte boundary. Such access maps - * into 2 shadow bytes, so we need to check them both. - */ - if (unlikely(((addr + size - 1) & KASAN_SHADOW_MASK) < size - 1)) - return *shadow_addr || memory_is_poisoned_1(addr + size - 1); - - return memory_is_poisoned_1(addr + size - 1); -} - -static __always_inline bool memory_is_poisoned_16(unsigned long addr) -{ - u16 *shadow_addr = (u16 *)kasan_mem_to_shadow((void *)addr); - - /* Unaligned 16-bytes access maps into 3 shadow bytes. */ - if (unlikely(!IS_ALIGNED(addr, KASAN_SHADOW_SCALE_SIZE))) - return *shadow_addr || memory_is_poisoned_1(addr + 15); - - return *shadow_addr; -} - -static __always_inline unsigned long bytes_is_nonzero(const u8 *start, - size_t size) -{ - while (size) { - if (unlikely(*start)) - return (unsigned long)start; - start++; - size--; - } - - return 0; -} - -static __always_inline unsigned long memory_is_nonzero(const void *start, - const void *end) -{ - unsigned int words; - unsigned long ret; - unsigned int prefix = (unsigned long)start % 8; - - if (end - start <= 16) - return bytes_is_nonzero(start, end - start); - - if (prefix) { - prefix = 8 - prefix; - ret = bytes_is_nonzero(start, prefix); - if (unlikely(ret)) - return ret; - start += prefix; - } - - words = (end - start) / 8; - while (words) { - if (unlikely(*(u64 *)start)) - return bytes_is_nonzero(start, 8); - start += 8; - words--; - } - - return bytes_is_nonzero(start, (end - start) % 8); -} - -static __always_inline bool memory_is_poisoned_n(unsigned long addr, - size_t size) -{ - unsigned long ret; - - ret = memory_is_nonzero(kasan_mem_to_shadow((void *)addr), - kasan_mem_to_shadow((void *)addr + size - 1) + 1); - - if (unlikely(ret)) { - unsigned long last_byte = addr + size - 1; - s8 *last_shadow = (s8 *)kasan_mem_to_shadow((void *)last_byte); - - if (unlikely(ret != (unsigned long)last_shadow || - ((long)(last_byte & KASAN_SHADOW_MASK) >= *last_shadow))) - return true; - } - return false; -} - -static __always_inline bool memory_is_poisoned(unsigned long addr, size_t size) -{ - if (__builtin_constant_p(size)) { - switch (size) { - case 1: - return memory_is_poisoned_1(addr); - case 2: - case 4: - case 8: - return memory_is_poisoned_2_4_8(addr, size); - case 16: - return memory_is_poisoned_16(addr); - default: - BUILD_BUG(); - } - } - - return memory_is_poisoned_n(addr, size); -} - -static __always_inline void check_memory_region_inline(unsigned long addr, - size_t size, bool write, - unsigned long ret_ip) -{ - if (unlikely(size == 0)) - return; - - if (unlikely((void *)addr < - kasan_shadow_to_mem((void *)KASAN_SHADOW_START))) { - kasan_report(addr, size, write, ret_ip); - return; - } - - if (likely(!memory_is_poisoned(addr, size))) - return; - - kasan_report(addr, size, write, ret_ip); -} - -void check_memory_region(unsigned long addr, size_t size, bool write, - unsigned long ret_ip) -{ - check_memory_region_inline(addr, size, write, ret_ip); -} - -void kasan_cache_shrink(struct kmem_cache *cache) -{ - quarantine_remove_cache(cache); -} - -void kasan_cache_shutdown(struct kmem_cache *cache) -{ - if (!__kmem_cache_empty(cache)) - quarantine_remove_cache(cache); -} - -static void register_global(struct kasan_global *global) -{ - size_t aligned_size = round_up(global->size, KASAN_SHADOW_SCALE_SIZE); - - kasan_unpoison_shadow(global->beg, global->size); - - kasan_poison_shadow(global->beg + aligned_size, - global->size_with_redzone - aligned_size, - KASAN_GLOBAL_REDZONE); -} - -void __asan_register_globals(struct kasan_global *globals, size_t size) -{ - int i; - - for (i = 0; i < size; i++) - register_global(&globals[i]); -} -EXPORT_SYMBOL(__asan_register_globals); - -void __asan_unregister_globals(struct kasan_global *globals, size_t size) -{ -} -EXPORT_SYMBOL(__asan_unregister_globals); - -#define DEFINE_ASAN_LOAD_STORE(size) \ - void __asan_load##size(unsigned long addr) \ - { \ - check_memory_region_inline(addr, size, false, _RET_IP_);\ - } \ - EXPORT_SYMBOL(__asan_load##size); \ - __alias(__asan_load##size) \ - void __asan_load##size##_noabort(unsigned long); \ - EXPORT_SYMBOL(__asan_load##size##_noabort); \ - void __asan_store##size(unsigned long addr) \ - { \ - check_memory_region_inline(addr, size, true, _RET_IP_); \ - } \ - EXPORT_SYMBOL(__asan_store##size); \ - __alias(__asan_store##size) \ - void __asan_store##size##_noabort(unsigned long); \ - EXPORT_SYMBOL(__asan_store##size##_noabort) - -DEFINE_ASAN_LOAD_STORE(1); -DEFINE_ASAN_LOAD_STORE(2); -DEFINE_ASAN_LOAD_STORE(4); -DEFINE_ASAN_LOAD_STORE(8); -DEFINE_ASAN_LOAD_STORE(16); - -void __asan_loadN(unsigned long addr, size_t size) -{ - check_memory_region(addr, size, false, _RET_IP_); -} -EXPORT_SYMBOL(__asan_loadN); - -__alias(__asan_loadN) -void __asan_loadN_noabort(unsigned long, size_t); -EXPORT_SYMBOL(__asan_loadN_noabort); - -void __asan_storeN(unsigned long addr, size_t size) -{ - check_memory_region(addr, size, true, _RET_IP_); -} -EXPORT_SYMBOL(__asan_storeN); - -__alias(__asan_storeN) -void __asan_storeN_noabort(unsigned long, size_t); -EXPORT_SYMBOL(__asan_storeN_noabort); - -/* to shut up compiler complaints */ -void __asan_handle_no_return(void) {} -EXPORT_SYMBOL(__asan_handle_no_return); - -/* Emitted by compiler to poison large objects when they go out of scope. */ -void __asan_poison_stack_memory(const void *addr, size_t size) -{ - /* - * Addr is KASAN_SHADOW_SCALE_SIZE-aligned and the object is surrounded - * by redzones, so we simply round up size to simplify logic. - */ - kasan_poison_shadow(addr, round_up(size, KASAN_SHADOW_SCALE_SIZE), - KASAN_USE_AFTER_SCOPE); -} -EXPORT_SYMBOL(__asan_poison_stack_memory); - -/* Emitted by compiler to unpoison large objects when they go into scope. */ -void __asan_unpoison_stack_memory(const void *addr, size_t size) -{ - kasan_unpoison_shadow(addr, size); -} -EXPORT_SYMBOL(__asan_unpoison_stack_memory); - -/* Emitted by compiler to poison alloca()ed objects. */ -void __asan_alloca_poison(unsigned long addr, size_t size) -{ - size_t rounded_up_size = round_up(size, KASAN_SHADOW_SCALE_SIZE); - size_t padding_size = round_up(size, KASAN_ALLOCA_REDZONE_SIZE) - - rounded_up_size; - size_t rounded_down_size = round_down(size, KASAN_SHADOW_SCALE_SIZE); - - const void *left_redzone = (const void *)(addr - - KASAN_ALLOCA_REDZONE_SIZE); - const void *right_redzone = (const void *)(addr + rounded_up_size); - - WARN_ON(!IS_ALIGNED(addr, KASAN_ALLOCA_REDZONE_SIZE)); - - kasan_unpoison_shadow((const void *)(addr + rounded_down_size), - size - rounded_down_size); - kasan_poison_shadow(left_redzone, KASAN_ALLOCA_REDZONE_SIZE, - KASAN_ALLOCA_LEFT); - kasan_poison_shadow(right_redzone, - padding_size + KASAN_ALLOCA_REDZONE_SIZE, - KASAN_ALLOCA_RIGHT); -} -EXPORT_SYMBOL(__asan_alloca_poison); - -/* Emitted by compiler to unpoison alloca()ed areas when the stack unwinds. */ -void __asan_allocas_unpoison(const void *stack_top, const void *stack_bottom) -{ - if (unlikely(!stack_top || stack_top > stack_bottom)) - return; - - kasan_unpoison_shadow(stack_top, stack_bottom - stack_top); -} -EXPORT_SYMBOL(__asan_allocas_unpoison); - -/* Emitted by the compiler to [un]poison local variables. */ -#define DEFINE_ASAN_SET_SHADOW(byte) \ - void __asan_set_shadow_##byte(const void *addr, size_t size) \ - { \ - __memset((void *)addr, 0x##byte, size); \ - } \ - EXPORT_SYMBOL(__asan_set_shadow_##byte) - -DEFINE_ASAN_SET_SHADOW(00); -DEFINE_ASAN_SET_SHADOW(f1); -DEFINE_ASAN_SET_SHADOW(f2); -DEFINE_ASAN_SET_SHADOW(f3); -DEFINE_ASAN_SET_SHADOW(f5); -DEFINE_ASAN_SET_SHADOW(f8); --- a/mm/kasan/kasan_init.c +++ /dev/null @@ -1,488 +0,0 @@ -/* - * This file contains some kasan initialization code. - * - * Copyright (c) 2015 Samsung Electronics Co., Ltd. - * Author: Andrey Ryabinin <ryabinin.a.a@xxxxxxxxx> - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License version 2 as - * published by the Free Software Foundation. - * - */ - -#include <linux/memblock.h> -#include <linux/init.h> -#include <linux/kasan.h> -#include <linux/kernel.h> -#include <linux/mm.h> -#include <linux/pfn.h> -#include <linux/slab.h> - -#include <asm/page.h> -#include <asm/pgalloc.h> - -#include "kasan.h" - -/* - * This page serves two purposes: - * - It used as early shadow memory. The entire shadow region populated - * with this page, before we will be able to setup normal shadow memory. - * - Latter it reused it as zero shadow to cover large ranges of memory - * that allowed to access, but not handled by kasan (vmalloc/vmemmap ...). - */ -unsigned char kasan_zero_page[PAGE_SIZE] __page_aligned_bss; - -#if CONFIG_PGTABLE_LEVELS > 4 -p4d_t kasan_zero_p4d[MAX_PTRS_PER_P4D] __page_aligned_bss; -static inline bool kasan_p4d_table(pgd_t pgd) -{ - return pgd_page(pgd) == virt_to_page(lm_alias(kasan_zero_p4d)); -} -#else -static inline bool kasan_p4d_table(pgd_t pgd) -{ - return 0; -} -#endif -#if CONFIG_PGTABLE_LEVELS > 3 -pud_t kasan_zero_pud[PTRS_PER_PUD] __page_aligned_bss; -static inline bool kasan_pud_table(p4d_t p4d) -{ - return p4d_page(p4d) == virt_to_page(lm_alias(kasan_zero_pud)); -} -#else -static inline bool kasan_pud_table(p4d_t p4d) -{ - return 0; -} -#endif -#if CONFIG_PGTABLE_LEVELS > 2 -pmd_t kasan_zero_pmd[PTRS_PER_PMD] __page_aligned_bss; -static inline bool kasan_pmd_table(pud_t pud) -{ - return pud_page(pud) == virt_to_page(lm_alias(kasan_zero_pmd)); -} -#else -static inline bool kasan_pmd_table(pud_t pud) -{ - return 0; -} -#endif -pte_t kasan_zero_pte[PTRS_PER_PTE] __page_aligned_bss; - -static inline bool kasan_pte_table(pmd_t pmd) -{ - return pmd_page(pmd) == virt_to_page(lm_alias(kasan_zero_pte)); -} - -static inline bool kasan_zero_page_entry(pte_t pte) -{ - return pte_page(pte) == virt_to_page(lm_alias(kasan_zero_page)); -} - -static __init void *early_alloc(size_t size, int node) -{ - return memblock_alloc_try_nid(size, size, __pa(MAX_DMA_ADDRESS), - MEMBLOCK_ALLOC_ACCESSIBLE, node); -} - -static void __ref zero_pte_populate(pmd_t *pmd, unsigned long addr, - unsigned long end) -{ - pte_t *pte = pte_offset_kernel(pmd, addr); - pte_t zero_pte; - - zero_pte = pfn_pte(PFN_DOWN(__pa_symbol(kasan_zero_page)), PAGE_KERNEL); - zero_pte = pte_wrprotect(zero_pte); - - while (addr + PAGE_SIZE <= end) { - set_pte_at(&init_mm, addr, pte, zero_pte); - addr += PAGE_SIZE; - pte = pte_offset_kernel(pmd, addr); - } -} - -static int __ref zero_pmd_populate(pud_t *pud, unsigned long addr, - unsigned long end) -{ - pmd_t *pmd = pmd_offset(pud, addr); - unsigned long next; - - do { - next = pmd_addr_end(addr, end); - - if (IS_ALIGNED(addr, PMD_SIZE) && end - addr >= PMD_SIZE) { - pmd_populate_kernel(&init_mm, pmd, lm_alias(kasan_zero_pte)); - continue; - } - - if (pmd_none(*pmd)) { - pte_t *p; - - if (slab_is_available()) - p = pte_alloc_one_kernel(&init_mm, addr); - else - p = early_alloc(PAGE_SIZE, NUMA_NO_NODE); - if (!p) - return -ENOMEM; - - pmd_populate_kernel(&init_mm, pmd, p); - } - zero_pte_populate(pmd, addr, next); - } while (pmd++, addr = next, addr != end); - - return 0; -} - -static int __ref zero_pud_populate(p4d_t *p4d, unsigned long addr, - unsigned long end) -{ - pud_t *pud = pud_offset(p4d, addr); - unsigned long next; - - do { - next = pud_addr_end(addr, end); - if (IS_ALIGNED(addr, PUD_SIZE) && end - addr >= PUD_SIZE) { - pmd_t *pmd; - - pud_populate(&init_mm, pud, lm_alias(kasan_zero_pmd)); - pmd = pmd_offset(pud, addr); - pmd_populate_kernel(&init_mm, pmd, lm_alias(kasan_zero_pte)); - continue; - } - - if (pud_none(*pud)) { - pmd_t *p; - - if (slab_is_available()) { - p = pmd_alloc(&init_mm, pud, addr); - if (!p) - return -ENOMEM; - } else { - pud_populate(&init_mm, pud, - early_alloc(PAGE_SIZE, NUMA_NO_NODE)); - } - } - zero_pmd_populate(pud, addr, next); - } while (pud++, addr = next, addr != end); - - return 0; -} - -static int __ref zero_p4d_populate(pgd_t *pgd, unsigned long addr, - unsigned long end) -{ - p4d_t *p4d = p4d_offset(pgd, addr); - unsigned long next; - - do { - next = p4d_addr_end(addr, end); - if (IS_ALIGNED(addr, P4D_SIZE) && end - addr >= P4D_SIZE) { - pud_t *pud; - pmd_t *pmd; - - p4d_populate(&init_mm, p4d, lm_alias(kasan_zero_pud)); - pud = pud_offset(p4d, addr); - pud_populate(&init_mm, pud, lm_alias(kasan_zero_pmd)); - pmd = pmd_offset(pud, addr); - pmd_populate_kernel(&init_mm, pmd, - lm_alias(kasan_zero_pte)); - continue; - } - - if (p4d_none(*p4d)) { - pud_t *p; - - if (slab_is_available()) { - p = pud_alloc(&init_mm, p4d, addr); - if (!p) - return -ENOMEM; - } else { - p4d_populate(&init_mm, p4d, - early_alloc(PAGE_SIZE, NUMA_NO_NODE)); - } - } - zero_pud_populate(p4d, addr, next); - } while (p4d++, addr = next, addr != end); - - return 0; -} - -/** - * kasan_populate_zero_shadow - populate shadow memory region with - * kasan_zero_page - * @shadow_start - start of the memory range to populate - * @shadow_end - end of the memory range to populate - */ -int __ref kasan_populate_zero_shadow(const void *shadow_start, - const void *shadow_end) -{ - unsigned long addr = (unsigned long)shadow_start; - unsigned long end = (unsigned long)shadow_end; - pgd_t *pgd = pgd_offset_k(addr); - unsigned long next; - - do { - next = pgd_addr_end(addr, end); - - if (IS_ALIGNED(addr, PGDIR_SIZE) && end - addr >= PGDIR_SIZE) { - p4d_t *p4d; - pud_t *pud; - pmd_t *pmd; - - /* - * kasan_zero_pud should be populated with pmds - * at this moment. - * [pud,pmd]_populate*() below needed only for - * 3,2 - level page tables where we don't have - * puds,pmds, so pgd_populate(), pud_populate() - * is noops. - * - * The ifndef is required to avoid build breakage. - * - * With 5level-fixup.h, pgd_populate() is not nop and - * we reference kasan_zero_p4d. It's not defined - * unless 5-level paging enabled. - * - * The ifndef can be dropped once all KASAN-enabled - * architectures will switch to pgtable-nop4d.h. - */ -#ifndef __ARCH_HAS_5LEVEL_HACK - pgd_populate(&init_mm, pgd, lm_alias(kasan_zero_p4d)); -#endif - p4d = p4d_offset(pgd, addr); - p4d_populate(&init_mm, p4d, lm_alias(kasan_zero_pud)); - pud = pud_offset(p4d, addr); - pud_populate(&init_mm, pud, lm_alias(kasan_zero_pmd)); - pmd = pmd_offset(pud, addr); - pmd_populate_kernel(&init_mm, pmd, lm_alias(kasan_zero_pte)); - continue; - } - - if (pgd_none(*pgd)) { - p4d_t *p; - - if (slab_is_available()) { - p = p4d_alloc(&init_mm, pgd, addr); - if (!p) - return -ENOMEM; - } else { - pgd_populate(&init_mm, pgd, - early_alloc(PAGE_SIZE, NUMA_NO_NODE)); - } - } - zero_p4d_populate(pgd, addr, next); - } while (pgd++, addr = next, addr != end); - - return 0; -} - -static void kasan_free_pte(pte_t *pte_start, pmd_t *pmd) -{ - pte_t *pte; - int i; - - for (i = 0; i < PTRS_PER_PTE; i++) { - pte = pte_start + i; - if (!pte_none(*pte)) - return; - } - - pte_free_kernel(&init_mm, (pte_t *)page_to_virt(pmd_page(*pmd))); - pmd_clear(pmd); -} - -static void kasan_free_pmd(pmd_t *pmd_start, pud_t *pud) -{ - pmd_t *pmd; - int i; - - for (i = 0; i < PTRS_PER_PMD; i++) { - pmd = pmd_start + i; - if (!pmd_none(*pmd)) - return; - } - - pmd_free(&init_mm, (pmd_t *)page_to_virt(pud_page(*pud))); - pud_clear(pud); -} - -static void kasan_free_pud(pud_t *pud_start, p4d_t *p4d) -{ - pud_t *pud; - int i; - - for (i = 0; i < PTRS_PER_PUD; i++) { - pud = pud_start + i; - if (!pud_none(*pud)) - return; - } - - pud_free(&init_mm, (pud_t *)page_to_virt(p4d_page(*p4d))); - p4d_clear(p4d); -} - -static void kasan_free_p4d(p4d_t *p4d_start, pgd_t *pgd) -{ - p4d_t *p4d; - int i; - - for (i = 0; i < PTRS_PER_P4D; i++) { - p4d = p4d_start + i; - if (!p4d_none(*p4d)) - return; - } - - p4d_free(&init_mm, (p4d_t *)page_to_virt(pgd_page(*pgd))); - pgd_clear(pgd); -} - -static void kasan_remove_pte_table(pte_t *pte, unsigned long addr, - unsigned long end) -{ - unsigned long next; - - for (; addr < end; addr = next, pte++) { - next = (addr + PAGE_SIZE) & PAGE_MASK; - if (next > end) - next = end; - - if (!pte_present(*pte)) - continue; - - if (WARN_ON(!kasan_zero_page_entry(*pte))) - continue; - pte_clear(&init_mm, addr, pte); - } -} - -static void kasan_remove_pmd_table(pmd_t *pmd, unsigned long addr, - unsigned long end) -{ - unsigned long next; - - for (; addr < end; addr = next, pmd++) { - pte_t *pte; - - next = pmd_addr_end(addr, end); - - if (!pmd_present(*pmd)) - continue; - - if (kasan_pte_table(*pmd)) { - if (IS_ALIGNED(addr, PMD_SIZE) && - IS_ALIGNED(next, PMD_SIZE)) - pmd_clear(pmd); - continue; - } - pte = pte_offset_kernel(pmd, addr); - kasan_remove_pte_table(pte, addr, next); - kasan_free_pte(pte_offset_kernel(pmd, 0), pmd); - } -} - -static void kasan_remove_pud_table(pud_t *pud, unsigned long addr, - unsigned long end) -{ - unsigned long next; - - for (; addr < end; addr = next, pud++) { - pmd_t *pmd, *pmd_base; - - next = pud_addr_end(addr, end); - - if (!pud_present(*pud)) - continue; - - if (kasan_pmd_table(*pud)) { - if (IS_ALIGNED(addr, PUD_SIZE) && - IS_ALIGNED(next, PUD_SIZE)) - pud_clear(pud); - continue; - } - pmd = pmd_offset(pud, addr); - pmd_base = pmd_offset(pud, 0); - kasan_remove_pmd_table(pmd, addr, next); - kasan_free_pmd(pmd_base, pud); - } -} - -static void kasan_remove_p4d_table(p4d_t *p4d, unsigned long addr, - unsigned long end) -{ - unsigned long next; - - for (; addr < end; addr = next, p4d++) { - pud_t *pud; - - next = p4d_addr_end(addr, end); - - if (!p4d_present(*p4d)) - continue; - - if (kasan_pud_table(*p4d)) { - if (IS_ALIGNED(addr, P4D_SIZE) && - IS_ALIGNED(next, P4D_SIZE)) - p4d_clear(p4d); - continue; - } - pud = pud_offset(p4d, addr); - kasan_remove_pud_table(pud, addr, next); - kasan_free_pud(pud_offset(p4d, 0), p4d); - } -} - -void kasan_remove_zero_shadow(void *start, unsigned long size) -{ - unsigned long addr, end, next; - pgd_t *pgd; - - addr = (unsigned long)kasan_mem_to_shadow(start); - end = addr + (size >> KASAN_SHADOW_SCALE_SHIFT); - - if (WARN_ON((unsigned long)start % - (KASAN_SHADOW_SCALE_SIZE * PAGE_SIZE)) || - WARN_ON(size % (KASAN_SHADOW_SCALE_SIZE * PAGE_SIZE))) - return; - - for (; addr < end; addr = next) { - p4d_t *p4d; - - next = pgd_addr_end(addr, end); - - pgd = pgd_offset_k(addr); - if (!pgd_present(*pgd)) - continue; - - if (kasan_p4d_table(*pgd)) { - if (IS_ALIGNED(addr, PGDIR_SIZE) && - IS_ALIGNED(next, PGDIR_SIZE)) - pgd_clear(pgd); - continue; - } - - p4d = p4d_offset(pgd, addr); - kasan_remove_p4d_table(p4d, addr, next); - kasan_free_p4d(p4d_offset(pgd, 0), pgd); - } -} - -int kasan_add_zero_shadow(void *start, unsigned long size) -{ - int ret; - void *shadow_start, *shadow_end; - - shadow_start = kasan_mem_to_shadow(start); - shadow_end = shadow_start + (size >> KASAN_SHADOW_SCALE_SHIFT); - - if (WARN_ON((unsigned long)start % - (KASAN_SHADOW_SCALE_SIZE * PAGE_SIZE)) || - WARN_ON(size % (KASAN_SHADOW_SCALE_SIZE * PAGE_SIZE))) - return -EINVAL; - - ret = kasan_populate_zero_shadow(shadow_start, shadow_end); - if (ret) - kasan_remove_zero_shadow(shadow_start, - size >> KASAN_SHADOW_SCALE_SHIFT); - return ret; -} --- a/mm/kasan/Makefile~kasan-rename-source-files-to-reflect-the-new-naming-scheme +++ a/mm/kasan/Makefile @@ -1,14 +1,14 @@ # SPDX-License-Identifier: GPL-2.0 KASAN_SANITIZE := n UBSAN_SANITIZE_common.o := n -UBSAN_SANITIZE_kasan.o := n +UBSAN_SANITIZE_generic.o := n KCOV_INSTRUMENT := n -CFLAGS_REMOVE_kasan.o = -pg +CFLAGS_REMOVE_generic.o = -pg # Function splitter causes unnecessary splits in __asan_load1/__asan_store1 # see: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63533 CFLAGS_common.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector) -CFLAGS_kasan.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector) +CFLAGS_generic.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector) -obj-y := common.o kasan.o report.o kasan_init.o quarantine.o +obj-y := common.o generic.o report.o init.o quarantine.o _
