1 files changed, 175 insertions, 0 deletions
diff --git a/vendor/rustix/src/backend/linux_raw/param/libc_auxv.rs b/vendor/rustix/src/backend/linux_raw/param/libc_auxv.rs
new file mode 100644
index 0000000..cfdd7a5
--- /dev/null
+++ b/vendor/rustix/src/backend/linux_raw/param/libc_auxv.rs
@@ -0,0 +1,175 @@
+//! Linux auxv support, using libc.
+//!
+//! # 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;
+#[cfg(not(feature = "runtime"))]
+use core::ptr::null;
+use linux_raw_sys::elf::*;
+
+// `getauxval` wasn't supported in glibc until 2.16. Also this lets us use
+// `*mut` as the return type to preserve strict provenance.
+#[cfg(not(feature = "runtime"))]
+weak!(fn getauxval(c::c_ulong) -> *mut c::c_void);
+
+// With the "runtime" feature, go ahead and depend on `getauxval` existing so
+// that we never fail.
+#[cfg(feature = "runtime")]
+extern "C" {
+    fn getauxval(type_: c::c_ulong) -> *mut c::c_void;
+}
+
+#[cfg(feature = "runtime")]
+const AT_PHDR: c::c_ulong = 3;
+#[cfg(feature = "runtime")]
+const AT_PHENT: c::c_ulong = 4;
+#[cfg(feature = "runtime")]
+const AT_PHNUM: c::c_ulong = 5;
+#[cfg(feature = "runtime")]
+const AT_ENTRY: c::c_ulong = 9;
+const AT_HWCAP: c::c_ulong = 16;
+#[cfg(feature = "runtime")]
+const AT_RANDOM: c::c_ulong = 25;
+const AT_HWCAP2: c::c_ulong = 26;
+const AT_SECURE: c::c_ulong = 23;
+const AT_EXECFN: c::c_ulong = 31;
+const AT_SYSINFO_EHDR: c::c_ulong = 33;
+
+// Declare `sysconf` ourselves so that we don't depend on all of libc just for
+// this.
+extern "C" {
+    fn sysconf(name: c::c_int) -> c::c_long;
+}
+
+#[cfg(target_os = "android")]
+const _SC_PAGESIZE: c::c_int = 39;
+#[cfg(target_os = "linux")]
+const _SC_PAGESIZE: c::c_int = 30;
+#[cfg(target_os = "android")]
+const _SC_CLK_TCK: c::c_int = 6;
+#[cfg(target_os = "linux")]
+const _SC_CLK_TCK: c::c_int = 2;
+
+#[test]
+fn test_abi() {
+    const_assert_eq!(self::_SC_PAGESIZE, ::libc::_SC_PAGESIZE);
+    const_assert_eq!(self::_SC_CLK_TCK, ::libc::_SC_CLK_TCK);
+    const_assert_eq!(self::AT_HWCAP, ::libc::AT_HWCAP);
+    const_assert_eq!(self::AT_HWCAP2, ::libc::AT_HWCAP2);
+    const_assert_eq!(self::AT_EXECFN, ::libc::AT_EXECFN);
+    const_assert_eq!(self::AT_SECURE, ::libc::AT_SECURE);
+    const_assert_eq!(self::AT_SYSINFO_EHDR, ::libc::AT_SYSINFO_EHDR);
+    #[cfg(feature = "runtime")]
+    const_assert_eq!(self::AT_PHDR, ::libc::AT_PHDR);
+    #[cfg(feature = "runtime")]
+    const_assert_eq!(self::AT_PHNUM, ::libc::AT_PHNUM);
+    #[cfg(feature = "runtime")]
+    const_assert_eq!(self::AT_ENTRY, ::libc::AT_ENTRY);
+    #[cfg(feature = "runtime")]
+    const_assert_eq!(self::AT_RANDOM, ::libc::AT_RANDOM);
+}
+
+#[cfg(feature = "param")]
+#[inline]
+pub(crate) fn page_size() -> usize {
+    unsafe { sysconf(_SC_PAGESIZE) as usize }
+}
+
+#[cfg(feature = "param")]
+#[inline]
+pub(crate) fn clock_ticks_per_second() -> u64 {
+    unsafe { sysconf(_SC_CLK_TCK) as u64 }
+}
+
+#[cfg(feature = "param")]
+#[inline]
+pub(crate) fn linux_hwcap() -> (usize, usize) {
+    #[cfg(not(feature = "runtime"))]
+    unsafe {
+        if let Some(libc_getauxval) = getauxval.get() {
+            let hwcap = libc_getauxval(AT_HWCAP) as usize;
+            let hwcap2 = libc_getauxval(AT_HWCAP2) as usize;
+            (hwcap, hwcap2)
+        } else {
+            (0, 0)
+        }
+    }
+
+    #[cfg(feature = "runtime")]
+    unsafe {
+        let hwcap = getauxval(AT_HWCAP) as usize;
+        let hwcap2 = getauxval(AT_HWCAP2) as usize;
+        (hwcap, hwcap2)
+    }
+}
+
+#[cfg(feature = "param")]
+#[inline]
+pub(crate) fn linux_execfn() -> &'static CStr {
+    #[cfg(not(feature = "runtime"))]
+    unsafe {
+        if let Some(libc_getauxval) = getauxval.get() {
+            CStr::from_ptr(libc_getauxval(AT_EXECFN).cast())
+        } else {
+            cstr!("")
+        }
+    }
+
+    #[cfg(feature = "runtime")]
+    unsafe {
+        CStr::from_ptr(getauxval(AT_EXECFN).cast())
+    }
+}
+
+#[cfg(feature = "runtime")]
+#[inline]
+pub(crate) fn linux_secure() -> bool {
+    unsafe { getauxval(AT_SECURE) as usize != 0 }
+}
+
+#[cfg(feature = "runtime")]
+#[inline]
+pub(crate) fn exe_phdrs() -> (*const c::c_void, usize, usize) {
+    unsafe {
+        let phdr = getauxval(AT_PHDR) as *const c::c_void;
+        let phent = getauxval(AT_PHENT) as usize;
+        let phnum = getauxval(AT_PHNUM) as usize;
+        (phdr, phent, phnum)
+    }
+}
+
+/// `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 {
+    #[cfg(not(feature = "runtime"))]
+    unsafe {
+        if let Some(libc_getauxval) = getauxval.get() {
+            libc_getauxval(AT_SYSINFO_EHDR) as *const Elf_Ehdr
+        } else {
+            null()
+        }
+    }
+
+    #[cfg(feature = "runtime")]
+    unsafe {
+        getauxval(AT_SYSINFO_EHDR) as *const Elf_Ehdr
+    }
+}
+
+#[cfg(feature = "runtime")]
+#[inline]
+pub(crate) fn entry() -> usize {
+    unsafe { getauxval(AT_ENTRY) as usize }
+}
+
+#[cfg(feature = "runtime")]
+#[inline]
+pub(crate) fn random() -> *const [u8; 16] {
+    unsafe { getauxval(AT_RANDOM) as *const [u8; 16] }
+}