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Don't allow over-read on BufferedBlockDevice

pull/11986/head
Seppo Takalo 2019-11-18 15:01:16 +02:00
parent 191d3444bb
commit 8ab3984d33
1 changed files with 7 additions and 2 deletions
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9
features/storage/blockdevice/BufferedBlockDevice.cpp
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@ -134,6 +134,11 @@ int BufferedBlockDevice::read(void *b, bd_addr_t addr, bd_size_t size)
}
MBED_ASSERT(_write_cache && _read_buf);
if (!is_valid_read(addr, size)) {
return BD_ERROR_DEVICE_ERROR;
}
// Common case - no need to involve write cache or read buffer
if (_bd->is_valid_read(addr, size) &&
((addr + size <= _write_cache_addr) || (addr > _write_cache_addr + _bd_program_size))) {
@ -146,9 +151,9 @@ int BufferedBlockDevice::read(void *b, bd_addr_t addr, bd_size_t size)
while (size) {
bd_size_t chunk;
bool read_from_bd = true;
if (addr < _write_cache_addr) {
if (_write_cache_valid && addr < _write_cache_addr) {
chunk = std::min(size, _write_cache_addr - addr);
} else if ((addr >= _write_cache_addr) && (addr < _write_cache_addr + _bd_program_size)) {
} else if (_write_cache_valid && (addr >= _write_cache_addr) && (addr < _write_cache_addr + _bd_program_size)) {
// One case we need to take our data from cache
chunk = std::min(size, _bd_program_size - addr % _bd_program_size);
memcpy(buf, _write_cache + addr % _bd_program_size, chunk);