diff options
Diffstat (limited to 'vendor/rustix/src/backend/linux_raw/param/init.rs')
| -rw-r--r-- | vendor/rustix/src/backend/linux_raw/param/init.rs | 171 |
1 files changed, 0 insertions, 171 deletions
diff --git a/vendor/rustix/src/backend/linux_raw/param/init.rs b/vendor/rustix/src/backend/linux_raw/param/init.rs deleted file mode 100644 index fe29e9c..0000000 --- a/vendor/rustix/src/backend/linux_raw/param/init.rs +++ /dev/null @@ -1,171 +0,0 @@ -//! Linux auxv `init` function, for "use-explicitly-provided-auxv" mode. -//! -//! # Safety -//! -//! This uses raw pointers to locate and read the kernel-provided auxv array. -#![allow(unsafe_code)] - -use crate::backend::c; -#[cfg(feature = "param")] -use crate::ffi::CStr; -use core::ffi::c_void; -use core::ptr::{null_mut, read, NonNull}; -#[cfg(feature = "runtime")] -use core::sync::atomic::AtomicBool; -use core::sync::atomic::{AtomicPtr, AtomicUsize, Ordering}; -use linux_raw_sys::elf::*; -use linux_raw_sys::general::{ - AT_CLKTCK, AT_EXECFN, AT_HWCAP, AT_HWCAP2, AT_NULL, AT_PAGESZ, AT_SYSINFO_EHDR, -}; -#[cfg(feature = "runtime")] -use linux_raw_sys::general::{AT_ENTRY, AT_PHDR, AT_PHENT, AT_PHNUM, AT_RANDOM, AT_SECURE}; - -#[cfg(feature = "param")] -#[inline] -pub(crate) fn page_size() -> usize { - unsafe { PAGE_SIZE.load(Ordering::Relaxed) } -} - -#[cfg(feature = "param")] -#[inline] -pub(crate) fn clock_ticks_per_second() -> u64 { - unsafe { CLOCK_TICKS_PER_SECOND.load(Ordering::Relaxed) as u64 } -} - -#[cfg(feature = "param")] -#[inline] -pub(crate) fn linux_hwcap() -> (usize, usize) { - unsafe { - ( - HWCAP.load(Ordering::Relaxed), - HWCAP2.load(Ordering::Relaxed), - ) - } -} - -#[cfg(feature = "param")] -#[inline] -pub(crate) fn linux_execfn() -> &'static CStr { - let execfn = unsafe { EXECFN.load(Ordering::Relaxed) }; - - // SAFETY: We initialize `EXECFN` to a valid `CStr` pointer, and we assume - // the `AT_EXECFN` value provided by the kernel points to a valid C string. - unsafe { CStr::from_ptr(execfn.cast()) } -} - -#[cfg(feature = "runtime")] -#[inline] -pub(crate) fn linux_secure() -> bool { - unsafe { SECURE.load(Ordering::Relaxed) } -} - -#[cfg(feature = "runtime")] -#[inline] -pub(crate) fn exe_phdrs() -> (*const c_void, usize, usize) { - unsafe { - ( - PHDR.load(Ordering::Relaxed).cast(), - PHENT.load(Ordering::Relaxed), - PHNUM.load(Ordering::Relaxed), - ) - } -} - -/// `AT_SYSINFO_EHDR` isn't present on all platforms in all configurations, so -/// if we don't see it, this function returns a null pointer. -#[inline] -pub(in super::super) fn sysinfo_ehdr() -> *const Elf_Ehdr { - unsafe { SYSINFO_EHDR.load(Ordering::Relaxed) } -} - -#[cfg(feature = "runtime")] -#[inline] -pub(crate) fn entry() -> usize { - unsafe { ENTRY.load(Ordering::Relaxed) } -} - -#[cfg(feature = "runtime")] -#[inline] -pub(crate) fn random() -> *const [u8; 16] { - unsafe { RANDOM.load(Ordering::Relaxed) } -} - -static mut PAGE_SIZE: AtomicUsize = AtomicUsize::new(0); -static mut CLOCK_TICKS_PER_SECOND: AtomicUsize = AtomicUsize::new(0); -static mut HWCAP: AtomicUsize = AtomicUsize::new(0); -static mut HWCAP2: AtomicUsize = AtomicUsize::new(0); -static mut SYSINFO_EHDR: AtomicPtr<Elf_Ehdr> = AtomicPtr::new(null_mut()); -// Initialize `EXECFN` to a valid `CStr` pointer so that we don't need to check -// for null on every `execfn` call. -static mut EXECFN: AtomicPtr<c::c_char> = AtomicPtr::new(b"\0".as_ptr() as _); -#[cfg(feature = "runtime")] -static mut SECURE: AtomicBool = AtomicBool::new(false); -// Use `dangling` so that we can always treat it like an empty slice. -#[cfg(feature = "runtime")] -static mut PHDR: AtomicPtr<Elf_Phdr> = AtomicPtr::new(NonNull::dangling().as_ptr()); -#[cfg(feature = "runtime")] -static mut PHENT: AtomicUsize = AtomicUsize::new(0); -#[cfg(feature = "runtime")] -static mut PHNUM: AtomicUsize = AtomicUsize::new(0); -#[cfg(feature = "runtime")] -static mut ENTRY: AtomicUsize = AtomicUsize::new(0); -#[cfg(feature = "runtime")] -static mut RANDOM: AtomicPtr<[u8; 16]> = AtomicPtr::new(NonNull::dangling().as_ptr()); - -/// When "use-explicitly-provided-auxv" is enabled, we export a function to be -/// called during initialization, and passed a pointer to the original -/// environment variable block set up by the OS. -pub(crate) unsafe fn init(envp: *mut *mut u8) { - init_from_envp(envp); -} - -/// # Safety -/// -/// This must be passed a pointer to the environment variable buffer -/// provided by the kernel, which is followed in memory by the auxv array. -unsafe fn init_from_envp(mut envp: *mut *mut u8) { - while !(*envp).is_null() { - envp = envp.add(1); - } - init_from_auxp(envp.add(1).cast()) -} - -/// Process auxv entries from the auxv array pointed to by `auxp`. -/// -/// # Safety -/// -/// This must be passed a pointer to an auxv array. -/// -/// The buffer contains `Elf_aux_t` elements, though it need not be aligned; -/// function uses `read_unaligned` to read from it. -unsafe fn init_from_auxp(mut auxp: *const Elf_auxv_t) { - loop { - let Elf_auxv_t { a_type, a_val } = read(auxp); - - match a_type as _ { - AT_PAGESZ => PAGE_SIZE.store(a_val as usize, Ordering::Relaxed), - AT_CLKTCK => CLOCK_TICKS_PER_SECOND.store(a_val as usize, Ordering::Relaxed), - AT_HWCAP => HWCAP.store(a_val as usize, Ordering::Relaxed), - AT_HWCAP2 => HWCAP2.store(a_val as usize, Ordering::Relaxed), - AT_EXECFN => EXECFN.store(a_val.cast::<c::c_char>(), Ordering::Relaxed), - AT_SYSINFO_EHDR => SYSINFO_EHDR.store(a_val.cast::<Elf_Ehdr>(), Ordering::Relaxed), - - #[cfg(feature = "runtime")] - AT_SECURE => SECURE.store(a_val as usize != 0, Ordering::Relaxed), - #[cfg(feature = "runtime")] - AT_PHDR => PHDR.store(a_val.cast::<Elf_Phdr>(), Ordering::Relaxed), - #[cfg(feature = "runtime")] - AT_PHNUM => PHNUM.store(a_val as usize, Ordering::Relaxed), - #[cfg(feature = "runtime")] - AT_PHENT => PHENT.store(a_val as usize, Ordering::Relaxed), - #[cfg(feature = "runtime")] - AT_ENTRY => ENTRY.store(a_val as usize, Ordering::Relaxed), - #[cfg(feature = "runtime")] - AT_RANDOM => RANDOM.store(a_val.cast::<[u8; 16]>(), Ordering::Relaxed), - - AT_NULL => break, - _ => (), - } - auxp = auxp.add(1); - } -} |