diff options
| -rw-r--r-- | drivers/io/io_memmap.c | 36 |
1 files changed, 27 insertions, 9 deletions
diff --git a/drivers/io/io_memmap.c b/drivers/io/io_memmap.c index 53af4f68..5104fb19 100644 --- a/drivers/io/io_memmap.c +++ b/drivers/io/io_memmap.c @@ -119,13 +119,14 @@ static int memmap_dev_close(io_dev_info_t *dev_info) /* Open a file on the memmap device */ -/* TODO: Can we do any sensible limit checks on requested memory */ static int memmap_block_open(io_dev_info_t *dev_info, const uintptr_t spec, io_entity_t *entity) { int result = -ENOMEM; const io_block_spec_t *block_spec = (io_block_spec_t *)spec; + assert(block_spec->length >= 0); + /* Since we need to track open state for seek() we only allow one open * spec at a time. When we have dynamic memory we can malloc and set * entity->info. @@ -153,13 +154,19 @@ static int memmap_block_open(io_dev_info_t *dev_info, const uintptr_t spec, static int memmap_block_seek(io_entity_t *entity, int mode, ssize_t offset) { int result = -ENOENT; + file_state_t *fp; /* We only support IO_SEEK_SET for the moment. */ if (mode == IO_SEEK_SET) { assert(entity != NULL); - /* TODO: can we do some basic limit checks on seek? */ - ((file_state_t *)entity->info)->file_pos = offset; + fp = (file_state_t *) entity->info; + + /* Assert that new file position is valid */ + assert((offset >= 0) && (offset < fp->size)); + + /* Reset file position */ + fp->file_pos = offset; result = 0; } @@ -184,18 +191,24 @@ static int memmap_block_read(io_entity_t *entity, uintptr_t buffer, size_t length, size_t *length_read) { file_state_t *fp; + size_t pos_after; assert(entity != NULL); assert(buffer != (uintptr_t)NULL); assert(length_read != NULL); - fp = (file_state_t *)entity->info; + fp = (file_state_t *) entity->info; + + /* Assert that file position is valid for this read operation */ + pos_after = fp->file_pos + length; + assert((pos_after >= fp->file_pos) && (pos_after <= fp->size)); memcpy((void *)buffer, (void *)(fp->base + fp->file_pos), length); *length_read = length; - /* advance the file 'cursor' for incremental reads */ - fp->file_pos += length; + + /* Set file position after read */ + fp->file_pos = pos_after; return 0; } @@ -206,19 +219,24 @@ static int memmap_block_write(io_entity_t *entity, const uintptr_t buffer, size_t length, size_t *length_written) { file_state_t *fp; + size_t pos_after; assert(entity != NULL); assert(buffer != (uintptr_t)NULL); assert(length_written != NULL); - fp = (file_state_t *)entity->info; + fp = (file_state_t *) entity->info; + + /* Assert that file position is valid for this write operation */ + pos_after = fp->file_pos + length; + assert((pos_after >= fp->file_pos) && (pos_after <= fp->size)); memcpy((void *)(fp->base + fp->file_pos), (void *)buffer, length); *length_written = length; - /* advance the file 'cursor' for incremental writes */ - fp->file_pos += length; + /* Set file position after write */ + fp->file_pos = pos_after; return 0; } |