Commit fee0c579 authored by Andrey Konovalov's avatar Andrey Konovalov Committed by Stephen Rothwell
Browse files

kasan, arm64: implement HW_TAGS runtime

Provide implementation of KASAN functions required for the hardware
tag-based mode.  Those include core functions for memory and pointer
tagging (tags_hw.c) and bug reporting (report_tags_hw.c).  Also adapt
common KASAN code to support the new mode.

Link: https://lkml.kernel.org/r/cfd0fbede579a6b66755c98c88c108e54f9c56bf.1606161801.git.andreyknvl@google.com

Signed-off-by: default avatarAndrey Konovalov <andreyknvl@google.com>
Signed-off-by: Vincenzo Frascino's avatarVincenzo Frascino <vincenzo.frascino@arm.com>
Acked-by: Catalin Marinas's avatarCatalin Marinas <catalin.marinas@arm.com>
Reviewed-by: default avatarAlexander Potapenko <glider@google.com>
Tested-by: Vincenzo Frascino's avatarVincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Marco Elver <elver@google.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarStephen Rothwell <sfr@canb.auug.org.au>
parent e19c6b02
......@@ -214,7 +214,7 @@ static inline unsigned long kaslr_offset(void)
(__force __typeof__(addr))__addr; \
})
#ifdef CONFIG_KASAN_SW_TAGS
#if defined(CONFIG_KASAN_SW_TAGS) || defined(CONFIG_KASAN_HW_TAGS)
#define __tag_shifted(tag) ((u64)(tag) << 56)
#define __tag_reset(addr) __untagged_addr(addr)
#define __tag_get(addr) (__u8)((u64)(addr) >> 56)
......@@ -222,7 +222,7 @@ static inline unsigned long kaslr_offset(void)
#define __tag_shifted(tag) 0UL
#define __tag_reset(addr) (addr)
#define __tag_get(addr) 0
#endif /* CONFIG_KASAN_SW_TAGS */
#endif /* CONFIG_KASAN_SW_TAGS || CONFIG_KASAN_HW_TAGS */
static inline const void *__tag_set(const void *addr, u8 tag)
{
......
......@@ -70,6 +70,7 @@
#include <linux/types.h>
#include <linux/mm.h>
#include <linux/cpu.h>
#include <linux/kasan.h>
#include <asm/cpu.h>
#include <asm/cpufeature.h>
#include <asm/cpu_ops.h>
......@@ -1713,6 +1714,8 @@ static void cpu_enable_mte(struct arm64_cpu_capabilities const *cap)
cleared_zero_page = true;
mte_clear_page_tags(lm_alias(empty_zero_page));
}
kasan_init_hw_tags_cpu();
}
#endif /* CONFIG_ARM64_MTE */
......
......@@ -462,6 +462,8 @@ void __init smp_prepare_boot_cpu(void)
/* Conditionally switch to GIC PMR for interrupt masking */
if (system_uses_irq_prio_masking())
init_gic_priority_masking();
kasan_init_hw_tags();
}
static u64 __init of_get_cpu_mpidr(struct device_node *dn)
......
......@@ -189,25 +189,35 @@ static inline void kasan_record_aux_stack(void *ptr) {}
#endif /* CONFIG_KASAN_GENERIC */
#ifdef CONFIG_KASAN_SW_TAGS
void __init kasan_init_sw_tags(void);
#if defined(CONFIG_KASAN_SW_TAGS) || defined(CONFIG_KASAN_HW_TAGS)
void *kasan_reset_tag(const void *addr);
bool kasan_report(unsigned long addr, size_t size,
bool is_write, unsigned long ip);
#else /* CONFIG_KASAN_SW_TAGS */
static inline void kasan_init_sw_tags(void) { }
#else /* CONFIG_KASAN_SW_TAGS || CONFIG_KASAN_HW_TAGS */
static inline void *kasan_reset_tag(const void *addr)
{
return (void *)addr;
}
#endif /* CONFIG_KASAN_SW_TAGS */
#endif /* CONFIG_KASAN_SW_TAGS || CONFIG_KASAN_HW_TAGS*/
#ifdef CONFIG_KASAN_SW_TAGS
void __init kasan_init_sw_tags(void);
#else
static inline void kasan_init_sw_tags(void) { }
#endif
#ifdef CONFIG_KASAN_HW_TAGS
void kasan_init_hw_tags_cpu(void);
void __init kasan_init_hw_tags(void);
#else
static inline void kasan_init_hw_tags_cpu(void) { }
static inline void kasan_init_hw_tags(void) { }
#endif
#ifdef CONFIG_KASAN_VMALLOC
......
......@@ -1421,7 +1421,7 @@ static inline bool cpupid_match_pid(struct task_struct *task, int cpupid)
}
#endif /* CONFIG_NUMA_BALANCING */
#ifdef CONFIG_KASAN_SW_TAGS
#if defined(CONFIG_KASAN_SW_TAGS) || defined(CONFIG_KASAN_HW_TAGS)
static inline u8 page_kasan_tag(const struct page *page)
{
return (page->flags >> KASAN_TAG_PGSHIFT) & KASAN_TAG_MASK;
......
......@@ -77,7 +77,7 @@
#define LAST_CPUPID_SHIFT 0
#endif
#ifdef CONFIG_KASAN_SW_TAGS
#if defined(CONFIG_KASAN_SW_TAGS) || defined(CONFIG_KASAN_HW_TAGS)
#define KASAN_TAG_WIDTH 8
#else
#define KASAN_TAG_WIDTH 0
......
......@@ -10,8 +10,10 @@ CFLAGS_REMOVE_init.o = $(CC_FLAGS_FTRACE)
CFLAGS_REMOVE_quarantine.o = $(CC_FLAGS_FTRACE)
CFLAGS_REMOVE_report.o = $(CC_FLAGS_FTRACE)
CFLAGS_REMOVE_report_generic.o = $(CC_FLAGS_FTRACE)
CFLAGS_REMOVE_report_hw_tags.o = $(CC_FLAGS_FTRACE)
CFLAGS_REMOVE_report_sw_tags.o = $(CC_FLAGS_FTRACE)
CFLAGS_REMOVE_shadow.o = $(CC_FLAGS_FTRACE)
CFLAGS_REMOVE_hw_tags.o = $(CC_FLAGS_FTRACE)
CFLAGS_REMOVE_sw_tags.o = $(CC_FLAGS_FTRACE)
# Function splitter causes unnecessary splits in __asan_load1/__asan_store1
......@@ -27,10 +29,13 @@ CFLAGS_init.o := $(CC_FLAGS_KASAN_RUNTIME)
CFLAGS_quarantine.o := $(CC_FLAGS_KASAN_RUNTIME)
CFLAGS_report.o := $(CC_FLAGS_KASAN_RUNTIME)
CFLAGS_report_generic.o := $(CC_FLAGS_KASAN_RUNTIME)
CFLAGS_report_hw_tags.o := $(CC_FLAGS_KASAN_RUNTIME)
CFLAGS_report_sw_tags.o := $(CC_FLAGS_KASAN_RUNTIME)
CFLAGS_shadow.o := $(CC_FLAGS_KASAN_RUNTIME)
CFLAGS_hw_tags.o := $(CC_FLAGS_KASAN_RUNTIME)
CFLAGS_sw_tags.o := $(CC_FLAGS_KASAN_RUNTIME)
obj-$(CONFIG_KASAN) := common.o report.o
obj-$(CONFIG_KASAN_GENERIC) += init.o generic.o report_generic.o shadow.o quarantine.o
obj-$(CONFIG_KASAN_HW_TAGS) += hw_tags.o report_hw_tags.o
obj-$(CONFIG_KASAN_SW_TAGS) += init.o report_sw_tags.o shadow.o sw_tags.o
......@@ -119,7 +119,7 @@ void kasan_free_pages(struct page *page, unsigned int order)
*/
static inline unsigned int optimal_redzone(unsigned int object_size)
{
if (IS_ENABLED(CONFIG_KASAN_SW_TAGS))
if (!IS_ENABLED(CONFIG_KASAN_GENERIC))
return 0;
return
......@@ -184,14 +184,14 @@ size_t kasan_metadata_size(struct kmem_cache *cache)
struct kasan_alloc_meta *get_alloc_info(struct kmem_cache *cache,
const void *object)
{
return (void *)object + cache->kasan_info.alloc_meta_offset;
return (void *)reset_tag(object) + cache->kasan_info.alloc_meta_offset;
}
struct kasan_free_meta *get_free_info(struct kmem_cache *cache,
const void *object)
{
BUILD_BUG_ON(sizeof(struct kasan_free_meta) > 32);
return (void *)object + cache->kasan_info.free_meta_offset;
return (void *)reset_tag(object) + cache->kasan_info.free_meta_offset;
}
void kasan_poison_slab(struct page *page)
......@@ -273,9 +273,8 @@ void * __must_check kasan_init_slab_obj(struct kmem_cache *cache,
alloc_info = get_alloc_info(cache, object);
__memset(alloc_info, 0, sizeof(*alloc_info));
if (IS_ENABLED(CONFIG_KASAN_SW_TAGS))
object = set_tag(object,
assign_tag(cache, object, true, false));
if (IS_ENABLED(CONFIG_KASAN_SW_TAGS) || IS_ENABLED(CONFIG_KASAN_HW_TAGS))
object = set_tag(object, assign_tag(cache, object, true, false));
return (void *)object;
}
......@@ -349,10 +348,10 @@ static void *__kasan_kmalloc(struct kmem_cache *cache, const void *object,
redzone_end = round_up((unsigned long)object + cache->object_size,
KASAN_GRANULE_SIZE);
if (IS_ENABLED(CONFIG_KASAN_SW_TAGS))
if (IS_ENABLED(CONFIG_KASAN_SW_TAGS) || IS_ENABLED(CONFIG_KASAN_HW_TAGS))
tag = assign_tag(cache, object, false, keep_tag);
/* Tag is ignored in set_tag without CONFIG_KASAN_SW_TAGS */
/* Tag is ignored in set_tag without CONFIG_KASAN_SW/HW_TAGS */
unpoison_range(set_tag(object, tag), size);
poison_range((void *)redzone_start, redzone_end - redzone_start,
KASAN_KMALLOC_REDZONE);
......
// SPDX-License-Identifier: GPL-2.0
/*
* This file contains core hardware tag-based KASAN code.
*
* Copyright (c) 2020 Google, Inc.
* Author: Andrey Konovalov <andreyknvl@google.com>
*/
#define pr_fmt(fmt) "kasan: " fmt
#include <linux/kasan.h>
#include <linux/kernel.h>
#include <linux/kfence.h>
#include <linux/memory.h>
#include <linux/mm.h>
#include <linux/string.h>
#include <linux/types.h>
#include "kasan.h"
/* kasan_init_hw_tags_cpu() is called for each CPU. */
void kasan_init_hw_tags_cpu(void)
{
hw_init_tags(KASAN_TAG_MAX);
hw_enable_tagging();
}
/* kasan_init_hw_tags() is called once on boot CPU. */
void __init kasan_init_hw_tags(void)
{
pr_info("KernelAddressSanitizer initialized\n");
}
void *kasan_reset_tag(const void *addr)
{
return reset_tag(addr);
}
void poison_range(const void *address, size_t size, u8 value)
{
/* Skip KFENCE memory if called explicitly outside of sl*b. */
if (is_kfence_address(address))
return;
hw_set_mem_tag_range(reset_tag(address),
round_up(size, KASAN_GRANULE_SIZE), value);
}
void unpoison_range(const void *address, size_t size)
{
/* Skip KFENCE memory if called explicitly outside of sl*b. */
if (is_kfence_address(address))
return;
hw_set_mem_tag_range(reset_tag(address),
round_up(size, KASAN_GRANULE_SIZE), get_tag(address));
}
u8 random_tag(void)
{
return hw_get_random_tag();
}
bool check_invalid_free(void *addr)
{
u8 ptr_tag = get_tag(addr);
u8 mem_tag = hw_get_mem_tag(addr);
return (mem_tag == KASAN_TAG_INVALID) ||
(ptr_tag != KASAN_TAG_KERNEL && ptr_tag != mem_tag);
}
void kasan_set_free_info(struct kmem_cache *cache,
void *object, u8 tag)
{
struct kasan_alloc_meta *alloc_meta;
alloc_meta = get_alloc_info(cache, object);
kasan_set_track(&alloc_meta->free_track[0], GFP_NOWAIT);
}
struct kasan_track *kasan_get_free_track(struct kmem_cache *cache,
void *object, u8 tag)
{
struct kasan_alloc_meta *alloc_meta;
alloc_meta = get_alloc_info(cache, object);
return &alloc_meta->free_track[0];
}
......@@ -154,6 +154,11 @@ struct kasan_alloc_meta *get_alloc_info(struct kmem_cache *cache,
struct kasan_free_meta *get_free_info(struct kmem_cache *cache,
const void *object);
void poison_range(const void *address, size_t size, u8 value);
void unpoison_range(const void *address, size_t size);
#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
static inline const void *kasan_shadow_to_mem(const void *shadow_addr)
{
return (void *)(((unsigned long)shadow_addr - KASAN_SHADOW_OFFSET)
......@@ -165,9 +170,6 @@ static inline bool addr_has_metadata(const void *addr)
return (addr >= kasan_shadow_to_mem((void *)KASAN_SHADOW_START));
}
void poison_range(const void *address, size_t size, u8 value);
void unpoison_range(const void *address, size_t size);
/**
* check_memory_region - Check memory region, and report if invalid access.
* @addr: the accessed address
......@@ -179,6 +181,15 @@ void unpoison_range(const void *address, size_t size);
bool check_memory_region(unsigned long addr, size_t size, bool write,
unsigned long ret_ip);
#else /* CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS */
static inline bool addr_has_metadata(const void *addr)
{
return true;
}
#endif /* CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS */
bool check_invalid_free(void *addr);
void *find_first_bad_addr(void *addr, size_t size);
......@@ -215,7 +226,7 @@ static inline void quarantine_reduce(void) { }
static inline void quarantine_remove_cache(struct kmem_cache *cache) { }
#endif
#ifdef CONFIG_KASAN_SW_TAGS
#if defined(CONFIG_KASAN_SW_TAGS) || defined(CONFIG_KASAN_HW_TAGS)
void print_tags(u8 addr_tag, const void *addr);
......
// SPDX-License-Identifier: GPL-2.0
/*
* This file contains hardware tag-based KASAN specific error reporting code.
*
* Copyright (c) 2020 Google, Inc.
* Author: Andrey Konovalov <andreyknvl@google.com>
*/
#include <linux/kasan.h>
#include <linux/kernel.h>
#include <linux/memory.h>
#include <linux/mm.h>
#include <linux/string.h>
#include <linux/types.h>
#include "kasan.h"
const char *get_bug_type(struct kasan_access_info *info)
{
return "invalid-access";
}
void *find_first_bad_addr(void *addr, size_t size)
{
return reset_tag(addr);
}
void metadata_fetch_row(char *buffer, void *row)
{
int i;
for (i = 0; i < META_BYTES_PER_ROW; i++)
buffer[i] = hw_get_mem_tag(row + i * KASAN_GRANULE_SIZE);
}
void print_tags(u8 addr_tag, const void *addr)
{
u8 memory_tag = hw_get_mem_tag((void *)addr);
pr_err("Pointer tag: [%02x], memory tag: [%02x]\n",
addr_tag, memory_tag);
}
// SPDX-License-Identifier: GPL-2.0
/*
* This file contains tag-based KASAN specific error reporting code.
* This file contains software tag-based KASAN specific error reporting code.
*
* Copyright (c) 2014 Samsung Electronics Co., Ltd.
* Author: Andrey Ryabinin <ryabinin.a.a@gmail.com>
......
......@@ -120,7 +120,7 @@ void unpoison_range(const void *address, size_t size)
if (IS_ENABLED(CONFIG_KASAN_SW_TAGS))
*shadow = tag;
else
else /* CONFIG_KASAN_GENERIC */
*shadow = size & KASAN_GRANULE_MASK;
}
}
......
// SPDX-License-Identifier: GPL-2.0
/*
* This file contains core tag-based KASAN code.
* This file contains core software tag-based KASAN code.
*
* Copyright (c) 2018 Google, Inc.
* Author: Andrey Konovalov <andreyknvl@google.com>
......
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