NAME
mprotect —
control the protection of
pages
SYNOPSIS
#include
<sys/mman.h>
int
mprotect(void *addr,
size_t len, int prot);
DESCRIPTION
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.
RETURN VALUES
Upon successful completion, a value of 0 is returned. Otherwise, a value of -1 is returned and errno is set to indicate the error.
ERRORS
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).
- [
ENOMEM] - The specified address range is outside of the address range of the process or includes an unmapped page.
- [
ENOTSUP] - The combination of accesses requested in prot is not supported.
LEGACY SYNOPSIS
#include
<sys/types.h> #include
<sys/mman.h>
The include file
<sys/types.h> is
necessary.
int
mprotect(caddr_t
addr, size_t len, int
prot);;
The type of addr has changed.
SEE ALSO
HISTORY
The mprotect() function first appeared in
4.4BSD.