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use nix::sys::mman::{mmap, MapFlags, ProtFlags};
use std::{num::NonZeroUsize, os::unix::io::BorrowedFd};
#[test]
fn test_mmap_anonymous() {
unsafe {
let ptr = mmap::<BorrowedFd>(
None,
NonZeroUsize::new(1).unwrap(),
ProtFlags::PROT_READ | ProtFlags::PROT_WRITE,
MapFlags::MAP_PRIVATE | MapFlags::MAP_ANONYMOUS,
None,
0,
)
.unwrap() as *mut u8;
assert_eq!(*ptr, 0x00u8);
*ptr = 0xffu8;
assert_eq!(*ptr, 0xffu8);
}
}
#[test]
#[cfg(any(target_os = "linux", target_os = "netbsd"))]
fn test_mremap_grow() {
use nix::libc::{c_void, size_t};
use nix::sys::mman::{mremap, MRemapFlags};
const ONE_K: size_t = 1024;
let one_k_non_zero = NonZeroUsize::new(ONE_K).unwrap();
let slice: &mut [u8] = unsafe {
let mem = mmap::<BorrowedFd>(
None,
one_k_non_zero,
ProtFlags::PROT_READ | ProtFlags::PROT_WRITE,
MapFlags::MAP_ANONYMOUS | MapFlags::MAP_PRIVATE,
None,
0,
)
.unwrap();
std::slice::from_raw_parts_mut(mem as *mut u8, ONE_K)
};
assert_eq!(slice[ONE_K - 1], 0x00);
slice[ONE_K - 1] = 0xFF;
assert_eq!(slice[ONE_K - 1], 0xFF);
let slice: &mut [u8] = unsafe {
#[cfg(target_os = "linux")]
let mem = mremap(
slice.as_mut_ptr() as *mut c_void,
ONE_K,
10 * ONE_K,
MRemapFlags::MREMAP_MAYMOVE,
None,
)
.unwrap();
#[cfg(target_os = "netbsd")]
let mem = mremap(
slice.as_mut_ptr() as *mut c_void,
ONE_K,
10 * ONE_K,
MRemapFlags::MAP_REMAPDUP,
None,
)
.unwrap();
std::slice::from_raw_parts_mut(mem as *mut u8, 10 * ONE_K)
};
// The first KB should still have the old data in it.
assert_eq!(slice[ONE_K - 1], 0xFF);
// The additional range should be zero-init'd and accessible.
assert_eq!(slice[10 * ONE_K - 1], 0x00);
slice[10 * ONE_K - 1] = 0xFF;
assert_eq!(slice[10 * ONE_K - 1], 0xFF);
}
#[test]
#[cfg(any(target_os = "linux", target_os = "netbsd"))]
// Segfaults for unknown reasons under QEMU for 32-bit targets
#[cfg_attr(all(target_pointer_width = "32", qemu), ignore)]
fn test_mremap_shrink() {
use nix::libc::{c_void, size_t};
use nix::sys::mman::{mremap, MRemapFlags};
use std::num::NonZeroUsize;
const ONE_K: size_t = 1024;
let ten_one_k = NonZeroUsize::new(10 * ONE_K).unwrap();
let slice: &mut [u8] = unsafe {
let mem = mmap::<BorrowedFd>(
None,
ten_one_k,
ProtFlags::PROT_READ | ProtFlags::PROT_WRITE,
MapFlags::MAP_ANONYMOUS | MapFlags::MAP_PRIVATE,
None,
0,
)
.unwrap();
std::slice::from_raw_parts_mut(mem as *mut u8, ONE_K)
};
assert_eq!(slice[ONE_K - 1], 0x00);
slice[ONE_K - 1] = 0xFF;
assert_eq!(slice[ONE_K - 1], 0xFF);
let slice: &mut [u8] = unsafe {
let mem = mremap(
slice.as_mut_ptr() as *mut c_void,
ten_one_k.into(),
ONE_K,
MRemapFlags::empty(),
None,
)
.unwrap();
// Since we didn't supply MREMAP_MAYMOVE, the address should be the
// same.
assert_eq!(mem, slice.as_mut_ptr() as *mut c_void);
std::slice::from_raw_parts_mut(mem as *mut u8, ONE_K)
};
// The first KB should still be accessible and have the old data in it.
assert_eq!(slice[ONE_K - 1], 0xFF);
}
|
