diff options
Diffstat (limited to 'third_party/rust/nix/src/sys/mman.rs')
| -rw-r--r-- | third_party/rust/nix/src/sys/mman.rs | 599 |
1 files changed, 599 insertions, 0 deletions
diff --git a/third_party/rust/nix/src/sys/mman.rs b/third_party/rust/nix/src/sys/mman.rs new file mode 100644 index 0000000000..2bee091610 --- /dev/null +++ b/third_party/rust/nix/src/sys/mman.rs @@ -0,0 +1,599 @@ +//! Memory management declarations. + +use crate::errno::Errno; +#[cfg(not(target_os = "android"))] +use crate::NixPath; +use crate::Result; +#[cfg(not(target_os = "android"))] +#[cfg(feature = "fs")] +use crate::{fcntl::OFlag, sys::stat::Mode}; +use libc::{self, c_int, c_void, off_t, size_t}; +use std::{os::unix::io::RawFd, num::NonZeroUsize}; + +libc_bitflags! { + /// Desired memory protection of a memory mapping. + pub struct ProtFlags: c_int { + /// Pages cannot be accessed. + PROT_NONE; + /// Pages can be read. + PROT_READ; + /// Pages can be written. + PROT_WRITE; + /// Pages can be executed + PROT_EXEC; + /// Apply protection up to the end of a mapping that grows upwards. + #[cfg(any(target_os = "android", target_os = "linux"))] + #[cfg_attr(docsrs, doc(cfg(all())))] + PROT_GROWSDOWN; + /// Apply protection down to the beginning of a mapping that grows downwards. + #[cfg(any(target_os = "android", target_os = "linux"))] + #[cfg_attr(docsrs, doc(cfg(all())))] + PROT_GROWSUP; + } +} + +libc_bitflags! { + /// Additional parameters for [`mmap`]. + pub struct MapFlags: c_int { + /// Compatibility flag. Ignored. + MAP_FILE; + /// Share this mapping. Mutually exclusive with `MAP_PRIVATE`. + MAP_SHARED; + /// Create a private copy-on-write mapping. Mutually exclusive with `MAP_SHARED`. + MAP_PRIVATE; + /// Place the mapping at exactly the address specified in `addr`. + MAP_FIXED; + /// Place the mapping at exactly the address specified in `addr`, but never clobber an existing range. + #[cfg(target_os = "linux")] + #[cfg_attr(docsrs, doc(cfg(all())))] + MAP_FIXED_NOREPLACE; + /// To be used with `MAP_FIXED`, to forbid the system + /// to select a different address than the one specified. + #[cfg(target_os = "freebsd")] + #[cfg_attr(docsrs, doc(cfg(all())))] + MAP_EXCL; + /// Synonym for `MAP_ANONYMOUS`. + MAP_ANON; + /// The mapping is not backed by any file. + MAP_ANONYMOUS; + /// Put the mapping into the first 2GB of the process address space. + #[cfg(any(all(any(target_os = "android", target_os = "linux"), + any(target_arch = "x86", target_arch = "x86_64")), + all(target_os = "linux", target_env = "musl", any(target_arch = "x86", target_arch = "x86_64")), + all(target_os = "freebsd", target_pointer_width = "64")))] + #[cfg_attr(docsrs, doc(cfg(all())))] + MAP_32BIT; + /// Used for stacks; indicates to the kernel that the mapping should extend downward in memory. + #[cfg(any(target_os = "android", target_os = "linux"))] + #[cfg_attr(docsrs, doc(cfg(all())))] + MAP_GROWSDOWN; + /// Compatibility flag. Ignored. + #[cfg(any(target_os = "android", target_os = "linux"))] + #[cfg_attr(docsrs, doc(cfg(all())))] + MAP_DENYWRITE; + /// Compatibility flag. Ignored. + #[cfg(any(target_os = "android", target_os = "linux"))] + #[cfg_attr(docsrs, doc(cfg(all())))] + MAP_EXECUTABLE; + /// Mark the mmaped region to be locked in the same way as `mlock(2)`. + #[cfg(any(target_os = "android", target_os = "linux"))] + #[cfg_attr(docsrs, doc(cfg(all())))] + MAP_LOCKED; + /// Do not reserve swap space for this mapping. + /// + /// This was removed in FreeBSD 11 and is unused in DragonFlyBSD. + #[cfg(not(any(target_os = "dragonfly", target_os = "freebsd")))] + #[cfg_attr(docsrs, doc(cfg(all())))] + MAP_NORESERVE; + /// Populate page tables for a mapping. + #[cfg(any(target_os = "android", target_os = "linux"))] + #[cfg_attr(docsrs, doc(cfg(all())))] + MAP_POPULATE; + /// Only meaningful when used with `MAP_POPULATE`. Don't perform read-ahead. + #[cfg(any(target_os = "android", target_os = "linux"))] + #[cfg_attr(docsrs, doc(cfg(all())))] + MAP_NONBLOCK; + /// Allocate the mapping using "huge pages." + #[cfg(any(target_os = "android", target_os = "linux"))] + #[cfg_attr(docsrs, doc(cfg(all())))] + MAP_HUGETLB; + /// Make use of 64KB huge page (must be supported by the system) + #[cfg(target_os = "linux")] + #[cfg_attr(docsrs, doc(cfg(all())))] + MAP_HUGE_64KB; + /// Make use of 512KB huge page (must be supported by the system) + #[cfg(target_os = "linux")] + #[cfg_attr(docsrs, doc(cfg(all())))] + MAP_HUGE_512KB; + /// Make use of 1MB huge page (must be supported by the system) + #[cfg(target_os = "linux")] + #[cfg_attr(docsrs, doc(cfg(all())))] + MAP_HUGE_1MB; + /// Make use of 2MB huge page (must be supported by the system) + #[cfg(target_os = "linux")] + #[cfg_attr(docsrs, doc(cfg(all())))] + MAP_HUGE_2MB; + /// Make use of 8MB huge page (must be supported by the system) + #[cfg(target_os = "linux")] + #[cfg_attr(docsrs, doc(cfg(all())))] + MAP_HUGE_8MB; + /// Make use of 16MB huge page (must be supported by the system) + #[cfg(target_os = "linux")] + #[cfg_attr(docsrs, doc(cfg(all())))] + MAP_HUGE_16MB; + /// Make use of 32MB huge page (must be supported by the system) + #[cfg(target_os = "linux")] + #[cfg_attr(docsrs, doc(cfg(all())))] + MAP_HUGE_32MB; + /// Make use of 256MB huge page (must be supported by the system) + #[cfg(target_os = "linux")] + #[cfg_attr(docsrs, doc(cfg(all())))] + MAP_HUGE_256MB; + /// Make use of 512MB huge page (must be supported by the system) + #[cfg(target_os = "linux")] + #[cfg_attr(docsrs, doc(cfg(all())))] + MAP_HUGE_512MB; + /// Make use of 1GB huge page (must be supported by the system) + #[cfg(target_os = "linux")] + #[cfg_attr(docsrs, doc(cfg(all())))] + MAP_HUGE_1GB; + /// Make use of 2GB huge page (must be supported by the system) + #[cfg(target_os = "linux")] + #[cfg_attr(docsrs, doc(cfg(all())))] + MAP_HUGE_2GB; + /// Make use of 16GB huge page (must be supported by the system) + #[cfg(target_os = "linux")] + #[cfg_attr(docsrs, doc(cfg(all())))] + MAP_HUGE_16GB; + + /// Lock the mapped region into memory as with `mlock(2)`. + #[cfg(target_os = "netbsd")] + #[cfg_attr(docsrs, doc(cfg(all())))] + MAP_WIRED; + /// Causes dirtied data in the specified range to be flushed to disk only when necessary. + #[cfg(any(target_os = "dragonfly", target_os = "freebsd"))] + #[cfg_attr(docsrs, doc(cfg(all())))] + MAP_NOSYNC; + /// Rename private pages to a file. + /// + /// This was removed in FreeBSD 11 and is unused in DragonFlyBSD. + #[cfg(any(target_os = "netbsd", target_os = "openbsd"))] + #[cfg_attr(docsrs, doc(cfg(all())))] + MAP_RENAME; + /// Region may contain semaphores. + #[cfg(any(target_os = "dragonfly", target_os = "freebsd", target_os = "netbsd", target_os = "openbsd"))] + #[cfg_attr(docsrs, doc(cfg(all())))] + MAP_HASSEMAPHORE; + /// Region grows down, like a stack. + #[cfg(any(target_os = "android", target_os = "dragonfly", target_os = "freebsd", target_os = "linux", target_os = "openbsd"))] + #[cfg_attr(docsrs, doc(cfg(all())))] + MAP_STACK; + /// Pages in this mapping are not retained in the kernel's memory cache. + #[cfg(any(target_os = "ios", target_os = "macos"))] + #[cfg_attr(docsrs, doc(cfg(all())))] + MAP_NOCACHE; + /// Allows the W/X bit on the page, it's necessary on aarch64 architecture. + #[cfg(any(target_os = "ios", target_os = "macos"))] + #[cfg_attr(docsrs, doc(cfg(all())))] + MAP_JIT; + /// Allows to use large pages, underlying alignment based on size. + #[cfg(target_os = "freebsd")] + #[cfg_attr(docsrs, doc(cfg(all())))] + MAP_ALIGNED_SUPER; + /// Pages will be discarded in the core dumps. + #[cfg(target_os = "openbsd")] + #[cfg_attr(docsrs, doc(cfg(all())))] + MAP_CONCEAL; + } +} + +#[cfg(any(target_os = "linux", target_os = "netbsd"))] +libc_bitflags! { + /// Options for [`mremap`]. + pub struct MRemapFlags: c_int { + /// Permit the kernel to relocate the mapping to a new virtual address, if necessary. + #[cfg(target_os = "linux")] + #[cfg_attr(docsrs, doc(cfg(all())))] + MREMAP_MAYMOVE; + /// Place the mapping at exactly the address specified in `new_address`. + #[cfg(target_os = "linux")] + #[cfg_attr(docsrs, doc(cfg(all())))] + MREMAP_FIXED; + /// Place the mapping at exactly the address specified in `new_address`. + #[cfg(target_os = "netbsd")] + #[cfg_attr(docsrs, doc(cfg(all())))] + MAP_FIXED; + /// Allows to duplicate the mapping to be able to apply different flags on the copy. + #[cfg(target_os = "netbsd")] + #[cfg_attr(docsrs, doc(cfg(all())))] + MAP_REMAPDUP; + } +} + +libc_enum! { + /// Usage information for a range of memory to allow for performance optimizations by the kernel. + /// + /// Used by [`madvise`]. + #[repr(i32)] + #[non_exhaustive] + pub enum MmapAdvise { + /// No further special treatment. This is the default. + MADV_NORMAL, + /// Expect random page references. + MADV_RANDOM, + /// Expect sequential page references. + MADV_SEQUENTIAL, + /// Expect access in the near future. + MADV_WILLNEED, + /// Do not expect access in the near future. + MADV_DONTNEED, + /// Free up a given range of pages and its associated backing store. + #[cfg(any(target_os = "android", target_os = "linux"))] + #[cfg_attr(docsrs, doc(cfg(all())))] + MADV_REMOVE, + /// Do not make pages in this range available to the child after a `fork(2)`. + #[cfg(any(target_os = "android", target_os = "linux"))] + #[cfg_attr(docsrs, doc(cfg(all())))] + MADV_DONTFORK, + /// Undo the effect of `MADV_DONTFORK`. + #[cfg(any(target_os = "android", target_os = "linux"))] + #[cfg_attr(docsrs, doc(cfg(all())))] + MADV_DOFORK, + /// Poison the given pages. + /// + /// Subsequent references to those pages are treated like hardware memory corruption. + #[cfg(any(target_os = "android", target_os = "linux"))] + #[cfg_attr(docsrs, doc(cfg(all())))] + MADV_HWPOISON, + /// Enable Kernel Samepage Merging (KSM) for the given pages. + #[cfg(any(target_os = "android", target_os = "linux"))] + #[cfg_attr(docsrs, doc(cfg(all())))] + MADV_MERGEABLE, + /// Undo the effect of `MADV_MERGEABLE` + #[cfg(any(target_os = "android", target_os = "linux"))] + #[cfg_attr(docsrs, doc(cfg(all())))] + MADV_UNMERGEABLE, + /// Preserve the memory of each page but offline the original page. + #[cfg(any(target_os = "android", + all(target_os = "linux", any( + target_arch = "aarch64", + target_arch = "arm", + target_arch = "powerpc", + target_arch = "powerpc64", + target_arch = "s390x", + target_arch = "x86", + target_arch = "x86_64", + target_arch = "sparc64"))))] + MADV_SOFT_OFFLINE, + /// Enable Transparent Huge Pages (THP) for pages in the given range. + #[cfg(any(target_os = "android", target_os = "linux"))] + #[cfg_attr(docsrs, doc(cfg(all())))] + MADV_HUGEPAGE, + /// Undo the effect of `MADV_HUGEPAGE`. + #[cfg(any(target_os = "android", target_os = "linux"))] + #[cfg_attr(docsrs, doc(cfg(all())))] + MADV_NOHUGEPAGE, + /// Exclude the given range from a core dump. + #[cfg(any(target_os = "android", target_os = "linux"))] + #[cfg_attr(docsrs, doc(cfg(all())))] + MADV_DONTDUMP, + /// Undo the effect of an earlier `MADV_DONTDUMP`. + #[cfg(any(target_os = "android", target_os = "linux"))] + #[cfg_attr(docsrs, doc(cfg(all())))] + MADV_DODUMP, + /// Specify that the application no longer needs the pages in the given range. + MADV_FREE, + /// Request that the system not flush the current range to disk unless it needs to. + #[cfg(any(target_os = "dragonfly", target_os = "freebsd"))] + #[cfg_attr(docsrs, doc(cfg(all())))] + MADV_NOSYNC, + /// Undoes the effects of `MADV_NOSYNC` for any future pages dirtied within the given range. + #[cfg(any(target_os = "dragonfly", target_os = "freebsd"))] + #[cfg_attr(docsrs, doc(cfg(all())))] + MADV_AUTOSYNC, + /// Region is not included in a core file. + #[cfg(any(target_os = "dragonfly", target_os = "freebsd"))] + #[cfg_attr(docsrs, doc(cfg(all())))] + MADV_NOCORE, + /// Include region in a core file + #[cfg(any(target_os = "dragonfly", target_os = "freebsd"))] + #[cfg_attr(docsrs, doc(cfg(all())))] + MADV_CORE, + /// This process should not be killed when swap space is exhausted. + #[cfg(any(target_os = "freebsd"))] + #[cfg_attr(docsrs, doc(cfg(all())))] + MADV_PROTECT, + /// Invalidate the hardware page table for the given region. + #[cfg(target_os = "dragonfly")] + #[cfg_attr(docsrs, doc(cfg(all())))] + MADV_INVAL, + /// Set the offset of the page directory page to `value` for the virtual page table. + #[cfg(target_os = "dragonfly")] + #[cfg_attr(docsrs, doc(cfg(all())))] + MADV_SETMAP, + /// Indicates that the application will not need the data in the given range. + #[cfg(any(target_os = "ios", target_os = "macos"))] + #[cfg_attr(docsrs, doc(cfg(all())))] + MADV_ZERO_WIRED_PAGES, + /// Pages can be reused (by anyone). + #[cfg(any(target_os = "ios", target_os = "macos"))] + #[cfg_attr(docsrs, doc(cfg(all())))] + MADV_FREE_REUSABLE, + /// Caller wants to reuse those pages. + #[cfg(any(target_os = "ios", target_os = "macos"))] + #[cfg_attr(docsrs, doc(cfg(all())))] + MADV_FREE_REUSE, + // Darwin doesn't document this flag's behavior. + #[cfg(any(target_os = "ios", target_os = "macos"))] + #[cfg_attr(docsrs, doc(cfg(all())))] + #[allow(missing_docs)] + MADV_CAN_REUSE, + } +} + +libc_bitflags! { + /// Configuration flags for [`msync`]. + pub struct MsFlags: c_int { + /// Schedule an update but return immediately. + MS_ASYNC; + /// Invalidate all cached data. + MS_INVALIDATE; + /// Invalidate pages, but leave them mapped. + #[cfg(any(target_os = "ios", target_os = "macos"))] + #[cfg_attr(docsrs, doc(cfg(all())))] + MS_KILLPAGES; + /// Deactivate pages, but leave them mapped. + #[cfg(any(target_os = "ios", target_os = "macos"))] + #[cfg_attr(docsrs, doc(cfg(all())))] + MS_DEACTIVATE; + /// Perform an update and wait for it to complete. + MS_SYNC; + } +} + +#[cfg(not(target_os = "haiku"))] +libc_bitflags! { + /// Flags for [`mlockall`]. + pub struct MlockAllFlags: c_int { + /// Lock pages that are currently mapped into the address space of the process. + MCL_CURRENT; + /// Lock pages which will become mapped into the address space of the process in the future. + MCL_FUTURE; + } +} + +/// Locks all memory pages that contain part of the address range with `length` +/// bytes starting at `addr`. +/// +/// Locked pages never move to the swap area. +/// +/// # Safety +/// +/// `addr` must meet all the requirements described in the [`mlock(2)`] man page. +/// +/// [`mlock(2)`]: https://man7.org/linux/man-pages/man2/mlock.2.html +pub unsafe fn mlock(addr: *const c_void, length: size_t) -> Result<()> { + Errno::result(libc::mlock(addr, length)).map(drop) +} + +/// Unlocks all memory pages that contain part of the address range with +/// `length` bytes starting at `addr`. +/// +/// # Safety +/// +/// `addr` must meet all the requirements described in the [`munlock(2)`] man +/// page. +/// +/// [`munlock(2)`]: https://man7.org/linux/man-pages/man2/munlock.2.html +pub unsafe fn munlock(addr: *const c_void, length: size_t) -> Result<()> { + Errno::result(libc::munlock(addr, length)).map(drop) +} + +/// Locks all memory pages mapped into this process' address space. +/// +/// Locked pages never move to the swap area. For more information, see [`mlockall(2)`]. +/// +/// [`mlockall(2)`]: https://man7.org/linux/man-pages/man2/mlockall.2.html +#[cfg(not(target_os = "haiku"))] +pub fn mlockall(flags: MlockAllFlags) -> Result<()> { + unsafe { Errno::result(libc::mlockall(flags.bits())) }.map(drop) +} + +/// Unlocks all memory pages mapped into this process' address space. +/// +/// For more information, see [`munlockall(2)`]. +/// +/// [`munlockall(2)`]: https://man7.org/linux/man-pages/man2/munlockall.2.html +#[cfg(not(target_os = "haiku"))] +pub fn munlockall() -> Result<()> { + unsafe { Errno::result(libc::munlockall()) }.map(drop) +} + +/// allocate memory, or map files or devices into memory +/// +/// # Safety +/// +/// See the [`mmap(2)`] man page for detailed requirements. +/// +/// [`mmap(2)`]: https://man7.org/linux/man-pages/man2/mmap.2.html +pub unsafe fn mmap( + addr: Option<NonZeroUsize>, + length: NonZeroUsize, + prot: ProtFlags, + flags: MapFlags, + fd: RawFd, + offset: off_t, +) -> Result<*mut c_void> { + let ptr = addr.map_or( + std::ptr::null_mut(), + |a| usize::from(a) as *mut c_void + ); + + let ret = libc::mmap(ptr, length.into(), prot.bits(), flags.bits(), fd, offset); + + if ret == libc::MAP_FAILED { + Err(Errno::last()) + } else { + Ok(ret) + } +} + +/// Expands (or shrinks) an existing memory mapping, potentially moving it at +/// the same time. +/// +/// # Safety +/// +/// See the `mremap(2)` [man page](https://man7.org/linux/man-pages/man2/mremap.2.html) for +/// detailed requirements. +#[cfg(any(target_os = "linux", target_os = "netbsd"))] +pub unsafe fn mremap( + addr: *mut c_void, + old_size: size_t, + new_size: size_t, + flags: MRemapFlags, + new_address: Option<*mut c_void>, +) -> Result<*mut c_void> { + #[cfg(target_os = "linux")] + let ret = libc::mremap( + addr, + old_size, + new_size, + flags.bits(), + new_address.unwrap_or(std::ptr::null_mut()), + ); + #[cfg(target_os = "netbsd")] + let ret = libc::mremap( + addr, + old_size, + new_address.unwrap_or(std::ptr::null_mut()), + new_size, + flags.bits(), + ); + + if ret == libc::MAP_FAILED { + Err(Errno::last()) + } else { + Ok(ret) + } +} + +/// remove a mapping +/// +/// # Safety +/// +/// `addr` must meet all the requirements described in the [`munmap(2)`] man +/// page. +/// +/// [`munmap(2)`]: https://man7.org/linux/man-pages/man2/munmap.2.html +pub unsafe fn munmap(addr: *mut c_void, len: size_t) -> Result<()> { + Errno::result(libc::munmap(addr, len)).map(drop) +} + +/// give advice about use of memory +/// +/// # Safety +/// +/// See the [`madvise(2)`] man page. Take special care when using +/// [`MmapAdvise::MADV_FREE`]. +/// +/// [`madvise(2)`]: https://man7.org/linux/man-pages/man2/madvise.2.html +pub unsafe fn madvise( + addr: *mut c_void, + length: size_t, + advise: MmapAdvise, +) -> Result<()> { + Errno::result(libc::madvise(addr, length, advise as i32)).map(drop) +} + +/// Set protection of memory mapping. +/// +/// See [`mprotect(3)`](https://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 one_k_non_zero = std::num::NonZeroUsize::new(ONE_K).unwrap(); +/// let mut slice: &mut [u8] = unsafe { +/// let mem = mmap(None, one_k_non_zero, 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) +} + +/// synchronize a mapped region +/// +/// # Safety +/// +/// `addr` must meet all the requirements described in the [`msync(2)`] man +/// page. +/// +/// [`msync(2)`]: https://man7.org/linux/man-pages/man2/msync.2.html +pub unsafe fn msync( + addr: *mut c_void, + length: size_t, + flags: MsFlags, +) -> Result<()> { + Errno::result(libc::msync(addr, length, flags.bits())).map(drop) +} + +#[cfg(not(target_os = "android"))] +feature! { +#![feature = "fs"] +/// Creates and opens a new, or opens an existing, POSIX shared memory object. +/// +/// For more information, see [`shm_open(3)`]. +/// +/// [`shm_open(3)`]: https://man7.org/linux/man-pages/man3/shm_open.3.html +pub fn shm_open<P>( + name: &P, + flag: OFlag, + mode: Mode + ) -> Result<RawFd> + where P: ?Sized + NixPath +{ + let ret = name.with_nix_path(|cstr| { + #[cfg(any(target_os = "macos", target_os = "ios"))] + unsafe { + libc::shm_open(cstr.as_ptr(), flag.bits(), mode.bits() as libc::c_uint) + } + #[cfg(not(any(target_os = "macos", target_os = "ios")))] + unsafe { + libc::shm_open(cstr.as_ptr(), flag.bits(), mode.bits() as libc::mode_t) + } + })?; + + Errno::result(ret) +} +} + +/// Performs the converse of [`shm_open`], removing an object previously created. +/// +/// For more information, see [`shm_unlink(3)`]. +/// +/// [`shm_unlink(3)`]: https://man7.org/linux/man-pages/man3/shm_unlink.3.html +#[cfg(not(target_os = "android"))] +pub fn shm_unlink<P: ?Sized + NixPath>(name: &P) -> Result<()> { + let ret = + name.with_nix_path(|cstr| unsafe { libc::shm_unlink(cstr.as_ptr()) })?; + + Errno::result(ret).map(drop) +} |