Standard C Library (libc, -lc)

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

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.

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.

madvise(2), mincore(2), msync(2), munmap(2)

The mprotect system call first appeared in