MPROTECT — C Library Procedures

NAME

mprotect − set protection of memory mapping

SYNOPSIS

#include <sys/mman.h>
mprotect(addr, len, prot)
caddr_t addr; int len, prot;

DESCRIPTION

mprotect() changes the access protections on the mappings specified by the range [addr, addr + len) to be that specified by prot. Legitimate values for prot are the same as those permitted for mmap(2).

RETURN VALUE

mprotect() returns 0 on success, −1 on failure.

ERRORS

mprotect() will fail if:

EACCES prot specifies a protection which violates the access permission the process has to the underlying memory object.

EINVAL addr is not a multiple of the page size as returned by getpagesize(2).

ENOMEM Addresses in the range [addr, addr + len) are invalid for the address space of a process, or specify one or more pages which are not mapped.

When mprotect() fails for reasons other than EINVAL, the protections on some of the pages in the range [addr, addr + len) will have been changed. If the error occurs on some page at address addr2, then the protections of all whole pages in the range [addr, addr2) have been modified.

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