Merge branch 'mm-kasan-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip (46580009) · Commits · 戴 / test

arch/x86/include/asm/kasan.h

+3 −0

Original line number	Diff line number	Diff line
		#ifndef _ASM_X86_KASAN_H
		#define _ASM_X86_KASAN_H

		#include <linux/const.h>
		#define KASAN_SHADOW_OFFSET _AC(CONFIG_KASAN_SHADOW_OFFSET, UL)

		/*
		* Compiler uses shadow offset assuming that addresses start
		* from 0. Kernel addresses don't start from 0, so shadow

arch/x86/mm/kasan_init_64.c

+5 −118

Original line number	Diff line number	Diff line
		@@ -12,20 +12,6 @@
		extern pgd_t early_level4_pgt[PTRS_PER_PGD];
		extern struct range pfn_mapped[E820_X_MAX];

		static pud_t kasan_zero_pud[PTRS_PER_PUD] __page_aligned_bss;
		static pmd_t kasan_zero_pmd[PTRS_PER_PMD] __page_aligned_bss;
		static pte_t kasan_zero_pte[PTRS_PER_PTE] __page_aligned_bss;

		/*
		* This page used as early shadow. We don't use empty_zero_page
		* at early stages, stack instrumentation could write some garbage
		* to this page.
		* Latter we reuse it as zero shadow for large ranges of memory
		* that allowed to access, but not instrumented by kasan
		* (vmalloc/vmemmap ...).
		*/
		static unsigned char kasan_zero_page[PAGE_SIZE] __page_aligned_bss;

		static int __init map_range(struct range *range)
		{
		unsigned long start;
		@@ -62,106 +48,6 @@ static void __init kasan_map_early_shadow(pgd_t *pgd)
		}
		}

		static int __init zero_pte_populate(pmd_t *pmd, unsigned long addr,
		unsigned long end)
		{
		pte_t *pte = pte_offset_kernel(pmd, addr);

		while (addr + PAGE_SIZE <= end) {
		WARN_ON(!pte_none(*pte));
		set_pte(pte, __pte(__pa_nodebug(kasan_zero_page)
		\| __PAGE_KERNEL_RO));
		addr += PAGE_SIZE;
		pte = pte_offset_kernel(pmd, addr);
		}
		return 0;
		}

		static int __init zero_pmd_populate(pud_t *pud, unsigned long addr,
		unsigned long end)
		{
		int ret = 0;
		pmd_t *pmd = pmd_offset(pud, addr);

		while (IS_ALIGNED(addr, PMD_SIZE) && addr + PMD_SIZE <= end) {
		WARN_ON(!pmd_none(*pmd));
		set_pmd(pmd, __pmd(__pa_nodebug(kasan_zero_pte)
		\| _KERNPG_TABLE));
		addr += PMD_SIZE;
		pmd = pmd_offset(pud, addr);
		}
		if (addr < end) {
		if (pmd_none(*pmd)) {
		void *p = vmemmap_alloc_block(PAGE_SIZE, NUMA_NO_NODE);
		if (!p)
		return -ENOMEM;
		set_pmd(pmd, __pmd(__pa_nodebug(p) \| _KERNPG_TABLE));
		}
		ret = zero_pte_populate(pmd, addr, end);
		}
		return ret;
		}


		static int __init zero_pud_populate(pgd_t *pgd, unsigned long addr,
		unsigned long end)
		{
		int ret = 0;
		pud_t *pud = pud_offset(pgd, addr);

		while (IS_ALIGNED(addr, PUD_SIZE) && addr + PUD_SIZE <= end) {
		WARN_ON(!pud_none(*pud));
		set_pud(pud, __pud(__pa_nodebug(kasan_zero_pmd)
		\| _KERNPG_TABLE));
		addr += PUD_SIZE;
		pud = pud_offset(pgd, addr);
		}

		if (addr < end) {
		if (pud_none(*pud)) {
		void *p = vmemmap_alloc_block(PAGE_SIZE, NUMA_NO_NODE);
		if (!p)
		return -ENOMEM;
		set_pud(pud, __pud(__pa_nodebug(p) \| _KERNPG_TABLE));
		}
		ret = zero_pmd_populate(pud, addr, end);
		}
		return ret;
		}

		static int __init zero_pgd_populate(unsigned long addr, unsigned long end)
		{
		int ret = 0;
		pgd_t *pgd = pgd_offset_k(addr);

		while (IS_ALIGNED(addr, PGDIR_SIZE) && addr + PGDIR_SIZE <= end) {
		WARN_ON(!pgd_none(*pgd));
		set_pgd(pgd, __pgd(__pa_nodebug(kasan_zero_pud)
		\| _KERNPG_TABLE));
		addr += PGDIR_SIZE;
		pgd = pgd_offset_k(addr);
		}

		if (addr < end) {
		if (pgd_none(*pgd)) {
		void *p = vmemmap_alloc_block(PAGE_SIZE, NUMA_NO_NODE);
		if (!p)
		return -ENOMEM;
		set_pgd(pgd, __pgd(__pa_nodebug(p) \| _KERNPG_TABLE));
		}
		ret = zero_pud_populate(pgd, addr, end);
		}
		return ret;
		}


		static void __init populate_zero_shadow(const void start, const void end)
		{
		if (zero_pgd_populate((unsigned long)start, (unsigned long)end))
		panic("kasan: unable to map zero shadow!");
		}


		#ifdef CONFIG_KASAN_INLINE
		static int kasan_die_handler(struct notifier_block *self,
		unsigned long val,
		@@ -213,7 +99,7 @@ void __init kasan_init(void)

		clear_pgds(KASAN_SHADOW_START, KASAN_SHADOW_END);

		populate_zero_shadow((void *)KASAN_SHADOW_START,
		kasan_populate_zero_shadow((void *)KASAN_SHADOW_START,
		kasan_mem_to_shadow((void *)PAGE_OFFSET));

		for (i = 0; i < E820_X_MAX; i++) {
		@@ -223,14 +109,15 @@ void __init kasan_init(void)
		if (map_range(&pfn_mapped[i]))
		panic("kasan: unable to allocate shadow!");
		}
		populate_zero_shadow(kasan_mem_to_shadow((void *)PAGE_OFFSET + MAXMEM),
		kasan_populate_zero_shadow(
		kasan_mem_to_shadow((void *)PAGE_OFFSET + MAXMEM),
		kasan_mem_to_shadow((void *)__START_KERNEL_map));

		vmemmap_populate((unsigned long)kasan_mem_to_shadow(_stext),
		(unsigned long)kasan_mem_to_shadow(_end),
		NUMA_NO_NODE);

		populate_zero_shadow(kasan_mem_to_shadow((void *)MODULES_END),
		kasan_populate_zero_shadow(kasan_mem_to_shadow((void *)MODULES_END),
		(void *)KASAN_SHADOW_END);

		memset(kasan_zero_page, 0, PAGE_SIZE);

include/linux/kasan.h

+9 −1

Original line number	Diff line number	Diff line
		@@ -10,11 +10,19 @@ struct vm_struct;
		#ifdef CONFIG_KASAN

		#define KASAN_SHADOW_SCALE_SHIFT 3
		#define KASAN_SHADOW_OFFSET _AC(CONFIG_KASAN_SHADOW_OFFSET, UL)

		#include <asm/kasan.h>
		#include <asm/pgtable.h>
		#include <linux/sched.h>

		extern unsigned char kasan_zero_page[PAGE_SIZE];
		extern pte_t kasan_zero_pte[PTRS_PER_PTE];
		extern pmd_t kasan_zero_pmd[PTRS_PER_PMD];
		extern pud_t kasan_zero_pud[PTRS_PER_PUD];

		void kasan_populate_zero_shadow(const void *shadow_start,
		const void *shadow_end);

		static inline void kasan_mem_to_shadow(const void addr)
		{
		return (void *)((unsigned long)addr >> KASAN_SHADOW_SCALE_SHIFT)

mm/kasan/Makefile

+1 −1

Original line number	Diff line number	Diff line
		@@ -5,4 +5,4 @@ CFLAGS_REMOVE_kasan.o = -pg
		# see: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63533
		CFLAGS_kasan.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector)

		obj-y := kasan.o report.o
		obj-y := kasan.o report.o kasan_init.o

mm/kasan/kasan_init.c

0 → 100644

+152 −0

Original line number	Diff line number	Diff line
		/*
		* This file contains some kasan initialization code.
		*
		* Copyright (c) 2015 Samsung Electronics Co., Ltd.
		* Author: Andrey Ryabinin <ryabinin.a.a@gmail.com>
		*
		* 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/bootmem.h>
		#include <linux/init.h>
		#include <linux/kasan.h>
		#include <linux/kernel.h>
		#include <linux/memblock.h>
		#include <linux/pfn.h>

		#include <asm/page.h>
		#include <asm/pgalloc.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 > 3
		pud_t kasan_zero_pud[PTRS_PER_PUD] __page_aligned_bss;
		#endif
		#if CONFIG_PGTABLE_LEVELS > 2
		pmd_t kasan_zero_pmd[PTRS_PER_PMD] __page_aligned_bss;
		#endif
		pte_t kasan_zero_pte[PTRS_PER_PTE] __page_aligned_bss;

		static __init void *early_alloc(size_t size, int node)
		{
		return memblock_virt_alloc_try_nid(size, size, __pa(MAX_DMA_ADDRESS),
		BOOTMEM_ALLOC_ACCESSIBLE, node);
		}

		static void __init 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(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 void __init 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, kasan_zero_pte);
		continue;
		}

		if (pmd_none(*pmd)) {
		pmd_populate_kernel(&init_mm, pmd,
		early_alloc(PAGE_SIZE, NUMA_NO_NODE));
		}
		zero_pte_populate(pmd, addr, next);
		} while (pmd++, addr = next, addr != end);
		}

		static void __init zero_pud_populate(pgd_t *pgd, unsigned long addr,
		unsigned long end)
		{
		pud_t *pud = pud_offset(pgd, 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, kasan_zero_pmd);
		pmd = pmd_offset(pud, addr);
		pmd_populate_kernel(&init_mm, pmd, kasan_zero_pte);
		continue;
		}

		if (pud_none(*pud)) {
		pud_populate(&init_mm, pud,
		early_alloc(PAGE_SIZE, NUMA_NO_NODE));
		}
		zero_pmd_populate(pud, addr, next);
		} while (pud++, addr = next, addr != end);
		}

		/**
		* 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
		*/
		void __init 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) {
		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.
		*/
		pgd_populate(&init_mm, pgd, kasan_zero_pud);
		pud = pud_offset(pgd, addr);
		pud_populate(&init_mm, pud, kasan_zero_pmd);
		pmd = pmd_offset(pud, addr);
		pmd_populate_kernel(&init_mm, pmd, kasan_zero_pte);
		continue;
		}

		if (pgd_none(*pgd)) {
		pgd_populate(&init_mm, pgd,
		early_alloc(PAGE_SIZE, NUMA_NO_NODE));
		}
		zero_pud_populate(pgd, addr, next);
		} while (pgd++, addr = next, addr != end);
		}

Admin message