function::user_buffer_quoted - Linux
Overview
user_buffer_quoted lets you access the portion of a buffer designated for use by calls to __builtin_libcall function as a pointer to a null-terminated string.
Syntax
char* __function_user_buffer_quoted(int function_code, ...)
Options/Flags
None.
Examples
-
Getting the buffer pointer for read():
char* buffer = __read_user_buffer_quoted(4);
-
Getting the buffer pointer for open():
char* buffer = __open_user_buffer_quoted(5);
Common Issues
- Incorrect function code: Ensure you provide the correct function code corresponding to the desired system call. Incorrect codes will result in unexpected behavior or segmentation faults.
- Invalid arguments: Passing invalid arguments to the system call can lead to errors or undefined behavior. Double-check your arguments before making the call.
Integration
user_buffer_quoted is commonly used in conjunction with other Linux system call wrappers to access user-space buffers. Here’s an example with __builtin_libcall read():
#include <sys/syscall.h>
int main() {
char buffer[512];
long bytes_read = __builtin_libcall(_read, 0, buffer, sizeof(buffer));
// Do something with the data in buffer
return 0;
}
Related Commands
- read(2)
- open(2)
- memset(3)