nix/sys/
personality.rs

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1//! Process execution domains
2use crate::errno::Errno;
3use crate::Result;
4
5use libc::{self, c_int, c_ulong};
6
7libc_bitflags! {
8    /// Flags used and returned by [`get()`](fn.get.html) and
9    /// [`set()`](fn.set.html).
10    pub struct Persona: c_int {
11        /// Provide the legacy virtual address space layout.
12        ADDR_COMPAT_LAYOUT;
13        /// Disable address-space-layout randomization.
14        ADDR_NO_RANDOMIZE;
15        /// Limit the address space to 32 bits.
16        ADDR_LIMIT_32BIT;
17        /// Use `0xc0000000` as the offset at which to search a virtual memory
18        /// chunk on [`mmap(2)`], otherwise use `0xffffe000`.
19        ///
20        /// [`mmap(2)`]: https://man7.org/linux/man-pages/man2/mmap.2.html
21        ADDR_LIMIT_3GB;
22        /// User-space function pointers to signal handlers point to descriptors.
23        #[cfg(not(any(target_env = "musl", target_env = "uclibc")))]
24        FDPIC_FUNCPTRS;
25        /// Map page 0 as read-only.
26        MMAP_PAGE_ZERO;
27        /// `PROT_READ` implies `PROT_EXEC` for [`mmap(2)`].
28        ///
29        /// [`mmap(2)`]: https://man7.org/linux/man-pages/man2/mmap.2.html
30        READ_IMPLIES_EXEC;
31        /// No effects.
32        SHORT_INODE;
33        /// [`select(2)`], [`pselect(2)`], and [`ppoll(2)`] do not modify the
34        /// returned timeout argument when interrupted by a signal handler.
35        ///
36        /// [`select(2)`]: https://man7.org/linux/man-pages/man2/select.2.html
37        /// [`pselect(2)`]: https://man7.org/linux/man-pages/man2/pselect.2.html
38        /// [`ppoll(2)`]: https://man7.org/linux/man-pages/man2/ppoll.2.html
39        STICKY_TIMEOUTS;
40        /// Have [`uname(2)`] report a 2.6.40+ version number rather than a 3.x
41        /// version number.
42        ///
43        /// [`uname(2)`]: https://man7.org/linux/man-pages/man2/uname.2.html
44        #[cfg(not(any(target_env = "musl", target_env = "uclibc")))]
45        UNAME26;
46        /// No effects.
47        WHOLE_SECONDS;
48    }
49}
50
51/// Retrieve the current process personality.
52///
53/// Returns a Result containing a Persona instance.
54///
55/// Example:
56///
57/// ```
58/// # use nix::sys::personality::{self, Persona};
59/// let pers = personality::get().unwrap();
60/// assert!(!pers.contains(Persona::WHOLE_SECONDS));
61/// ```
62pub fn get() -> Result<Persona> {
63    let res = unsafe { libc::personality(0xFFFFFFFF) };
64
65    Errno::result(res).map(Persona::from_bits_truncate)
66}
67
68/// Set the current process personality.
69///
70/// Returns a Result containing the *previous* personality for the
71/// process, as a Persona.
72///
73/// For more information, see [personality(2)](https://man7.org/linux/man-pages/man2/personality.2.html)
74///
75/// **NOTE**: This call **replaces** the current personality entirely.
76/// To **update** the personality, first call `get()` and then `set()`
77/// with the modified persona.
78///
79/// Example:
80///
81// Disable test on aarch64 until we know why it fails.
82// https://github.com/nix-rust/nix/issues/2060
83#[cfg_attr(target_arch = "aarch64", doc = " ```no_run")]
84#[cfg_attr(not(target_arch = "aarch64"), doc = " ```")]
85/// # use nix::sys::personality::{self, Persona};
86/// let mut pers = personality::get().unwrap();
87/// assert!(!pers.contains(Persona::ADDR_NO_RANDOMIZE));
88/// personality::set(pers | Persona::ADDR_NO_RANDOMIZE).unwrap();
89/// ```
90pub fn set(persona: Persona) -> Result<Persona> {
91    let res = unsafe { libc::personality(persona.bits() as c_ulong) };
92
93    Errno::result(res).map(Persona::from_bits_truncate)
94}
nix/sys/personality.rs

nix/sys/
personality.rs
