incubator-nuttx/mm/kasan/global.c

137 lines
4.0 KiB
C

/****************************************************************************
* mm/kasan/global.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/nuttx.h>
#include <nuttx/mm/kasan.h>
#include <assert.h>
#include <stdint.h>
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#define KASAN_BYTES_PER_WORD (sizeof(uintptr_t))
#define KASAN_BITS_PER_WORD (KASAN_BYTES_PER_WORD * 8)
#define KASAN_GLOBAL_FIRST_WORD_MASK(start) \
(UINTPTR_MAX << ((start) & (KASAN_BITS_PER_WORD - 1)))
#define KASAN_GLOBAL_LAST_WORD_MASK(end) \
(UINTPTR_MAX >> (-(end) & (KASAN_BITS_PER_WORD - 1)))
/****************************************************************************
* Private Types
****************************************************************************/
struct kasan_global_region_s
{
uintptr_t begin;
uintptr_t end;
uintptr_t shadow[1];
};
/****************************************************************************
* Public Data
****************************************************************************/
extern const struct kasan_global_region_s *g_global_region[];
/****************************************************************************
* Private Functions
****************************************************************************/
static inline_function FAR uintptr_t *
kasan_global_mem_to_shadow(FAR const void *ptr, size_t size,
FAR unsigned int *bit)
{
uintptr_t addr = (uintptr_t)ptr;
size_t i;
for (i = 0; g_global_region[i]; i++)
{
if (addr >= g_global_region[i]->begin &&
addr < g_global_region[i]->end)
{
DEBUGASSERT(addr + size <= g_global_region[i]->end);
addr -= g_global_region[i]->begin;
addr /= CONFIG_MM_KASAN_GLOBAL_ALIGN;
*bit = addr % KASAN_BITS_PER_WORD;
return (FAR uintptr_t *)
&g_global_region[i]->shadow[addr / KASAN_BITS_PER_WORD];
}
}
return NULL;
}
static inline_function bool
kasan_global_is_poisoned(FAR const void *addr, size_t size)
{
FAR uintptr_t *p;
unsigned int bit;
unsigned int nbit;
uintptr_t mask;
p = kasan_global_mem_to_shadow(addr, size, &bit);
if (p == NULL)
{
return false;
}
if (size <= CONFIG_MM_KASAN_GLOBAL_ALIGN)
{
return ((*p >> bit) & 1);
}
nbit = KASAN_BITS_PER_WORD - bit % KASAN_BITS_PER_WORD;
mask = KASAN_GLOBAL_FIRST_WORD_MASK(bit);
size = ALIGN_UP(size, CONFIG_MM_KASAN_GLOBAL_ALIGN);
size /= CONFIG_MM_KASAN_GLOBAL_ALIGN;
while (size >= nbit)
{
if ((*p++ & mask) != 0)
{
return true;
}
bit += nbit;
size -= nbit;
nbit = KASAN_BITS_PER_WORD;
mask = UINTPTR_MAX;
}
if (size)
{
mask &= KASAN_GLOBAL_LAST_WORD_MASK(bit + size);
if ((*p & mask) != 0)
{
return true;
}
}
return false;
}