zx_vmo_read

NAME

Read bytes from the VMO.

SYNOPSIS

#include <zircon/syscalls.h>

zx_status_t zx_vmo_read(zx_handle_t handle,
                        void* buffer,
                        uint64_t offset,
                        size_t buffer_size);

DESCRIPTION

zx_vmo_read() attempts to read exactly buffer_size bytes from a VMO at offset.

buffer pointer to a user buffer to read bytes into.

buffer_size number of bytes to attempt to read. buffer buffer should be large enough for at least this many bytes.

RIGHTS

handle must be of type ZX_OBJ_TYPE_VMO and have ZX_RIGHT_READ.

RETURN VALUE

zx_vmo_read() returns ZX_OK on success, and exactly buffer_size bytes will have been written to buffer. In the event of failure, a negative error value is returned, and the number of bytes written to buffer is undefined.

ERRORS

ZX_ERR_BAD_HANDLE handle is not a valid handle.

ZX_ERR_WRONG_TYPE handle is not a VMO handle.

ZX_ERR_ACCESS_DENIED handle does not have the ZX_RIGHT_READ right.

ZX_ERR_INVALID_ARGS buffer is an invalid pointer or NULL.

ZX_ERR_OUT_OF_RANGE offset + buffer_size is greater than the size of the VMO.

ZX_ERR_BAD_STATE VMO has been marked uncached and is not directly readable.

SEE ALSO