MPROTECT(2) BSD System Calls Manual MPROTECT(2)
mprotect -- control the protection of pages
mprotect(void *addr, size_t len, int prot);
The mprotect() system call changes the specified pages to have protection prot. Not all implementations will guarantee protection on a page
basis but Mac OS X's current implementation does.
When a program violates the protections of a page, it gets a SIGBUS or SIGSEGV signal.
Currently prot can be one or more of the following:
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.
Upon successful completion, a value of 0 is returned. Otherwise, a value of -1 is returned and errno is set to indicate the error.
mprotect() will fail if:
[EACCES] The requested protection conflicts with the access permissions of the process on the specified address range.
[EINVAL] addr is not a multiple of the page size (i.e. addr is not page-aligned).
[ENOTSUP] The combination of accesses requested in prot is not supported.
The include file <sys/types.h> is necessary.
mprotect(caddr_t addr, size_t len, int prot);
The type of addr has changed.
madvise(2), mincore(2), msync(2), munmap(2), compat(5)
The mprotect() function first appeared in 4.4BSD.
October 16, 2008 BSD