1 //! Process execution domains
2 use crate::errno::Errno;
3 use crate::Result;
4
5 use libc::{self, c_int, c_ulong};
6
7 libc_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 /// ```
get() -> Result<Persona>62 pub 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 /// ```
set(persona: Persona) -> Result<Persona>90 pub 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 }
95