suword Kernel Service
Purpose
Stores a word of data in user memory.
Syntax
Parameters
| Item | Description |
|---|---|
| uaddr | Specifies the address of user data. |
| w | Specifies the word to store. |
Description
The suword kernel service stores a word of data at the specified address in user memory. It is provided so that system calls and device heads can safely access user data. The suword service ensures that the user had the appropriate authority to:
- Access the data.
- Protect the operating system from paging I/O errors on user data.
The suword service should only be called while executing in kernel mode in the user process.
Execution Environment
The suword kernel service can be called from the process environment only.
Return Values
| Item | Description |
|---|---|
| 0 | Indicates successful completion. |
| -1 | Indicates a uaddr parameter that is not valid for
one of these reasons:
|