MPROTECT(2) | FreeBSD System Calls Manual | MPROTECT(2) |
NAME
mprotect — control the protection of pagesLIBRARY
Standard C Library (libc, -lc)DESCRIPTION
The mprotect() system call changes the specified pages to have protection prot. Not all implementations will guarantee protection on a page basis; the granularity of protection changes may be as large as an entire region. A region is the virtual address space defined by the start and end addresses of a struct vm_map_entry.Currently these protection bits are known, which can be combined, OR'd together:
- PROT_NONE
- No permissions at all.
- PROT_READ
- The pages can be read.
- PROT_WRITE
- The pages can be written.
- PROT_EXEC
- The pages can be executed.
RETURN VALUES
The mprotect() function returns the value 0 if successful; otherwise the value -1 is returned and the global variable errno is set to indicate the error.ERRORS
The mprotect() system call will fail if:- [ EINVAL]
- The virtual address range specified by the addr and len arguments is not valid.
- [ EACCES]
- The calling process was not allowed to change the protection to the value specified by the prot argument.
HISTORY
The mprotect() system call first appeared in 4.4BSD.June 9, 1993 | FreeBSD |