From 94dbad22032b61d98807bde100a73d0096070cd9 Mon Sep 17 00:00:00 2001 From: "Adam C. Foltzer" Date: Wed, 5 Dec 2018 10:55:59 -0800 Subject: add `mman::mprotect` --- src/sys/mman.rs | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+) (limited to 'src') diff --git a/src/sys/mman.rs b/src/sys/mman.rs index a30629db..dd92ffc0 100644 --- a/src/sys/mman.rs +++ b/src/sys/mman.rs @@ -258,6 +258,35 @@ pub unsafe fn madvise(addr: *mut c_void, length: size_t, advise: MmapAdvise) -> Errno::result(libc::madvise(addr, length, advise as i32)).map(drop) } +/// Set protection of memory mapping. +/// +/// See [`mprotect(3)`](http://pubs.opengroup.org/onlinepubs/9699919799/functions/mprotect.html) for +/// details. +/// +/// # Safety +/// +/// Calls to `mprotect` are inherently unsafe, as changes to memory protections can lead to +/// SIGSEGVs. +/// +/// ``` +/// # use nix::libc::size_t; +/// # use nix::sys::mman::{mmap, mprotect, MapFlags, ProtFlags}; +/// # use std::ptr; +/// const ONE_K: size_t = 1024; +/// let mut slice: &mut [u8] = unsafe { +/// let mem = mmap(ptr::null_mut(), ONE_K, ProtFlags::PROT_NONE, +/// MapFlags::MAP_ANON | MapFlags::MAP_PRIVATE, -1, 0).unwrap(); +/// mprotect(mem, ONE_K, ProtFlags::PROT_READ | ProtFlags::PROT_WRITE).unwrap(); +/// std::slice::from_raw_parts_mut(mem as *mut u8, ONE_K) +/// }; +/// assert_eq!(slice[0], 0x00); +/// slice[0] = 0xFF; +/// assert_eq!(slice[0], 0xFF); +/// ``` +pub unsafe fn mprotect(addr: *mut c_void, length: size_t, prot: ProtFlags) -> Result<()> { + Errno::result(libc::mprotect(addr, length, prot.bits())).map(drop) +} + pub unsafe fn msync(addr: *mut c_void, length: size_t, flags: MsFlags) -> Result<()> { Errno::result(libc::msync(addr, length, flags.bits())).map(drop) } -- cgit v1.2.3