# zx_process_write_memory ## NAME process_write_memory - Write into the given process's address space. ## SYNOPSIS ``` #include zx_status_t zx_process_write_memory(zx_handle_t handle, zx_vaddr_t vaddr, const void* buffer, size_t buffer_size, size_t* actual); ``` ## DESCRIPTION `zx_process_write_memory()` attempts to write memory of the specified process. This function will eventually be replaced with something vmo-centric. *vaddr* the address of the block of memory to write. *buffer* pointer to a user buffer containing the bytes to write. *buffer_size* number of bytes to attempt to write. *buffer* buffer must be large enough for at least this many bytes. *buffer_size* must be greater than zero and less than or equal to 64MB. *actual_size* the actual number of bytes written is stored here. Less bytes than requested may be returned if *vaddr*+*buffer_size* extends beyond the memory mapped in the process. ## RIGHTS *handle* must be of type **ZX_OBJ_TYPE_PROCESS** and have **ZX_RIGHT_WRITE**. ## RETURN VALUE `zx_process_write_memory()` returns **ZX_OK** on success. In the event of failure, a negative error value is returned, and the number of bytes written to *buffer* is undefined. ## ERRORS **ZX_ERR_ACCESS_DENIED** *handle* does not have the **ZX_RIGHT_WRITE** right. **ZX_ERR_BAD_HANDLE** *handle* is not a valid handle. **ZX_ERR_BAD_STATE** the process's memory is not accessible (e.g., the process is being terminated), or the requested memory is not cacheable. **ZX_ERR_INVALID_ARGS** *buffer* is an invalid pointer or NULL, or *buffer_size* is zero or greater than 64MB. **ZX_ERR_NO_MEMORY** the process does not have any memory at the requested address. **ZX_ERR_WRONG_TYPE** *handle* is not a process handle. ## SEE ALSO [process_read_memory](process_read_memory.md).