incubator-nuttx/mm/kasan/kasan.c

317 lines
8.5 KiB
C

/****************************************************************************
* mm/kasan/kasan.c
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/spinlock.h>
#include <assert.h>
#include <debug.h>
#include <stdbool.h>
#include <stdint.h>
#include "kasan.h"
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#define KASAN_BYTES_PER_WORD (sizeof(uintptr_t))
#define KASAN_BITS_PER_WORD (KASAN_BYTES_PER_WORD * 8)
#define KASAN_FIRST_WORD_MASK(start) \
(UINTPTR_MAX << ((start) & (KASAN_BITS_PER_WORD - 1)))
#define KASAN_LAST_WORD_MASK(end) \
(UINTPTR_MAX >> (-(end) & (KASAN_BITS_PER_WORD - 1)))
#define KASAN_SHADOW_SCALE (sizeof(uintptr_t))
#define KASAN_SHADOW_SIZE(size) \
(KASAN_BYTES_PER_WORD * ((size) / KASAN_SHADOW_SCALE / KASAN_BITS_PER_WORD))
#define KASAN_REGION_SIZE(size) \
(sizeof(struct kasan_region_s) + KASAN_SHADOW_SIZE(size))
#define KASAN_INIT_VALUE 0xDEADCAFE
/****************************************************************************
* Private Types
****************************************************************************/
struct kasan_region_s
{
FAR struct kasan_region_s *next;
uintptr_t begin;
uintptr_t end;
uintptr_t shadow[1];
};
/****************************************************************************
* Private Data
****************************************************************************/
static spinlock_t g_lock;
static FAR struct kasan_region_s *g_region;
static uint32_t g_region_init;
/****************************************************************************
* Private Functions
****************************************************************************/
static FAR uintptr_t *kasan_mem_to_shadow(FAR const void *ptr, size_t size,
unsigned int *bit)
{
FAR struct kasan_region_s *region;
uintptr_t addr = (uintptr_t)ptr;
if (g_region_init != KASAN_INIT_VALUE)
{
return NULL;
}
for (region = g_region; region != NULL; region = region->next)
{
if (addr >= region->begin && addr < region->end)
{
DEBUGASSERT(addr + size <= region->end);
addr -= region->begin;
addr /= KASAN_SHADOW_SCALE;
*bit = addr % KASAN_BITS_PER_WORD;
return &region->shadow[addr / KASAN_BITS_PER_WORD];
}
}
return NULL;
}
static void kasan_report(FAR const void *addr, size_t size,
bool is_write,
FAR void *return_address)
{
static int recursion;
if (++recursion == 1)
{
_alert("kasan detected a %s access error, address at %p,"
"size is %zu, return address: %p\n",
is_write ? "write" : "read",
addr, size, return_address);
PANIC();
}
--recursion;
}
static bool kasan_is_poisoned(FAR const void *addr, size_t size)
{
FAR uintptr_t *p;
unsigned int bit;
p = kasan_mem_to_shadow(addr + size - 1, 1, &bit);
return p && ((*p >> bit) & 1);
}
static void kasan_set_poison(FAR const void *addr, size_t size,
bool poisoned)
{
FAR uintptr_t *p;
unsigned int bit;
unsigned int nbit;
uintptr_t mask;
int flags;
flags = spin_lock_irqsave(&g_lock);
p = kasan_mem_to_shadow(addr, size, &bit);
DEBUGASSERT(p != NULL);
nbit = KASAN_BITS_PER_WORD - bit % KASAN_BITS_PER_WORD;
mask = KASAN_FIRST_WORD_MASK(bit);
size /= KASAN_SHADOW_SCALE;
while (size >= nbit)
{
if (poisoned)
{
*p++ |= mask;
}
else
{
*p++ &= ~mask;
}
bit += nbit;
size -= nbit;
nbit = KASAN_BITS_PER_WORD;
mask = UINTPTR_MAX;
}
if (size)
{
mask &= KASAN_LAST_WORD_MASK(bit + size);
if (poisoned)
{
*p |= mask;
}
else
{
*p &= ~mask;
}
}
spin_unlock_irqrestore(&g_lock, flags);
}
static inline void kasan_check_report(FAR const void *addr, size_t size,
bool is_write,
FAR void *return_address)
{
if (kasan_is_poisoned(addr, size))
{
kasan_report(addr, size, false, return_address);
}
}
/****************************************************************************
* Public Functions
****************************************************************************/
/* Exported functions called from other mm module */
void kasan_poison(FAR const void *addr, size_t size)
{
kasan_set_poison(addr, size, true);
}
void kasan_unpoison(FAR const void *addr, size_t size)
{
kasan_set_poison(addr, size, false);
}
void kasan_register(FAR void *addr, FAR size_t *size)
{
FAR struct kasan_region_s *region;
int flags;
region = (FAR struct kasan_region_s *)
((FAR char *)addr + *size - KASAN_REGION_SIZE(*size));
region->begin = (uintptr_t)addr;
region->end = region->begin + *size;
flags = spin_lock_irqsave(&g_lock);
region->next = g_region;
g_region = region;
g_region_init = KASAN_INIT_VALUE;
spin_unlock_irqrestore(&g_lock, flags);
kasan_poison(addr, *size);
*size -= KASAN_REGION_SIZE(*size);
}
/* Exported functions called from the compiler generated code */
void __sanitizer_annotate_contiguous_container(FAR const void *beg,
FAR const void *end,
FAR const void *old_mid,
FAR const void *new_mid)
{
/* Shut up compiler complaints */
}
void __asan_before_dynamic_init(FAR const void *module_name)
{
/* Shut up compiler complaints */
}
void __asan_after_dynamic_init(void)
{
/* Shut up compiler complaints */
}
void __asan_handle_no_return(void)
{
/* Shut up compiler complaints */
}
void __asan_report_load_n_noabort(FAR void *addr, size_t size)
{
kasan_report(addr, size, false, return_address(0));
}
void __asan_report_store_n_noabort(FAR void *addr, size_t size)
{
kasan_report(addr, size, true, return_address(0));
}
void __asan_loadN_noabort(FAR void *addr, size_t size)
{
kasan_check_report(addr, size, false, return_address(0));
}
void __asan_storeN_noabort(FAR void * addr, size_t size)
{
kasan_check_report(addr, size, true, return_address(0));
}
void __asan_loadN(FAR void *addr, size_t size)
{
kasan_check_report(addr, size, false, return_address(0));
}
void __asan_storeN(FAR void *addr, size_t size)
{
kasan_check_report(addr, size, true, return_address(0));
}
#define DEFINE_ASAN_LOAD_STORE(size) \
void __asan_report_load##size##_noabort(FAR void *addr) \
{ \
kasan_report(addr, size, false, return_address(0)); \
} \
void __asan_report_store##size##_noabort(FAR void *addr) \
{ \
kasan_report(addr, size, true, return_address(0)); \
} \
void __asan_load##size##_noabort(FAR void *addr) \
{ \
kasan_check_report(addr, size, false, return_address(0)); \
} \
void __asan_store##size##_noabort(FAR void *addr) \
{ \
kasan_check_report(addr, size, true, return_address(0)); \
} \
void __asan_load##size(FAR void *addr) \
{ \
kasan_check_report(addr, size, false, return_address(0)); \
} \
void __asan_store##size(FAR void *addr) \
{ \
kasan_check_report(addr, size, true, return_address(0)); \
}
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)