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authorValentin Popov <valentin@popov.link>2024-01-08 00:21:28 +0300
committerValentin Popov <valentin@popov.link>2024-01-08 00:21:28 +0300
commit1b6a04ca5504955c571d1c97504fb45ea0befee4 (patch)
tree7579f518b23313e8a9748a88ab6173d5e030b227 /vendor/portable-atomic/src/imp/atomic128/detect/auxv.rs
parent5ecd8cf2cba827454317368b68571df0d13d7842 (diff)
downloadfparkan-1b6a04ca5504955c571d1c97504fb45ea0befee4.tar.xz
fparkan-1b6a04ca5504955c571d1c97504fb45ea0befee4.zip
Initial vendor packages
Signed-off-by: Valentin Popov <valentin@popov.link>
Diffstat (limited to 'vendor/portable-atomic/src/imp/atomic128/detect/auxv.rs')
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+// SPDX-License-Identifier: Apache-2.0 OR MIT
+
+// Run-time feature detection on aarch64/powerpc64 Linux/Android/FreeBSD by parsing ELF auxiliary vectors.
+//
+// # Linux/Android
+//
+// As of nightly-2023-01-23, is_aarch64_feature_detected always uses dlsym by default
+// on aarch64 Linux/Android, but on the following platforms, so we can safely assume
+// getauxval is linked to the binary.
+//
+// - On glibc (*-linux-gnu*), [aarch64 support is available on glibc 2.17+](https://sourceware.org/legacy-ml/libc-announce/2012/msg00001.html)
+// and is newer than [glibc 2.16 that added getauxval](https://sourceware.org/legacy-ml/libc-announce/2012/msg00000.html).
+// - On musl (*-linux-musl*, *-linux-ohos*), [aarch64 support is available on musl 1.1.7+](https://git.musl-libc.org/cgit/musl/tree/WHATSNEW?h=v1.1.7#n1422)
+// and is newer than [musl 1.1.0 that added getauxval](https://git.musl-libc.org/cgit/musl/tree/WHATSNEW?h=v1.1.0#n1197).
+// https://github.com/rust-lang/rust/commit/9a04ae4997493e9260352064163285cddc43de3c
+// - On bionic (*-android*), [64-bit architecture support is available on Android 5.0+ (API level 21+)](https://android-developers.googleblog.com/2014/10/whats-new-in-android-50-lollipop.html)
+// and is newer than [Android 4.3 (API level 18) that added getauxval](https://github.com/aosp-mirror/platform_bionic/blob/d3ebc2f7c49a9893b114124d4a6b315f3a328764/libc/include/sys/auxv.h#L49).
+//
+// However, on musl with static linking, it seems that getauxval is not always available, independent of version requirements: https://github.com/rust-lang/rust/issues/89626
+// (That problem may have been fixed in https://github.com/rust-lang/rust/commit/9a04ae4997493e9260352064163285cddc43de3c,
+// but even in the version containing that patch, [there is report](https://github.com/rust-lang/rust/issues/89626#issuecomment-1242636038)
+// of the same error.)
+//
+// On other Linux targets, we cannot assume that getauxval is always available, so we don't enable
+// outline-atomics by default (can be enabled by `--cfg portable_atomic_outline_atomics`).
+//
+// - On musl with static linking. See the above for more.
+// Also, in this case, dlsym(getauxval) always returns null.
+// - On uClibc-ng (*-linux-uclibc*, *-l4re-uclibc*), [uClibc-ng 1.0.43 (released in 2023-04-05) added getauxval](https://github.com/wbx-github/uclibc-ng/commit/d869bb1600942c01a77539128f9ba5b5b55ad647).
+// - On Picolibc, [Picolibc 1.4.6 added getauxval stub](https://github.com/picolibc/picolibc#picolibc-version-146).
+//
+// See also https://github.com/rust-lang/stdarch/pull/1375
+//
+// See tests::test_linux_like and aarch64_aa64reg.rs for (test-only) alternative implementations.
+//
+// # FreeBSD
+//
+// As of nightly-2023-01-23, is_aarch64_feature_detected always uses mrs on
+// aarch64 FreeBSD. However, they do not work on FreeBSD 12 on QEMU (confirmed
+// on FreeBSD 12.{2,3,4}), and we got SIGILL (worked on FreeBSD 13 and 14).
+//
+// So use elf_aux_info instead of mrs like compiler-rt does.
+// https://man.freebsd.org/elf_aux_info(3)
+// https://reviews.llvm.org/D109330
+//
+// elf_aux_info is available on FreeBSD 12.0+ and 11.4+:
+// https://github.com/freebsd/freebsd-src/commit/0b08ae2120cdd08c20a2b806e2fcef4d0a36c470
+// https://github.com/freebsd/freebsd-src/blob/release/11.4.0/sys/sys/auxv.h
+// On FreeBSD, [aarch64 support is available on FreeBSD 11.0+](https://www.freebsd.org/releases/11.0R/relnotes/#hardware-arm),
+// but FreeBSD 11 (11.4) was EoL on 2021-09-30, and FreeBSD 11.3 was EoL on 2020-09-30:
+// https://www.freebsd.org/security/unsupported
+// See also https://github.com/rust-lang/stdarch/pull/611#issuecomment-445464613
+//
+// See tests::test_freebsd and aarch64_aa64reg.rs for (test-only) alternative implementations.
+//
+// # PowerPC64
+//
+// On PowerPC64, outline-atomics is currently disabled by default mainly for
+// compatibility with older versions of operating systems
+// (can be enabled by `--cfg portable_atomic_outline_atomics`).
+
+include!("common.rs");
+
+use os::ffi;
+#[cfg(any(target_os = "linux", target_os = "android"))]
+mod os {
+ // core::ffi::c_* (except c_void) requires Rust 1.64, libc will soon require Rust 1.47
+ #[cfg_attr(test, allow(dead_code))]
+ pub(super) mod ffi {
+ pub(crate) use super::super::c_types::c_ulong;
+ #[cfg(all(target_arch = "aarch64", target_os = "android"))]
+ pub(crate) use super::super::c_types::{c_char, c_int};
+
+ extern "C" {
+ // https://man7.org/linux/man-pages/man3/getauxval.3.html
+ // https://github.com/bminor/glibc/blob/801af9fafd4689337ebf27260aa115335a0cb2bc/misc/sys/auxv.h
+ // https://github.com/bminor/musl/blob/7d756e1c04de6eb3f2b3d3e1141a218bb329fcfb/include/sys/auxv.h
+ // https://github.com/wbx-github/uclibc-ng/blob/cdb07d2cd52af39feb425e6d36c02b30916b9f0a/include/sys/auxv.h
+ // https://github.com/aosp-mirror/platform_bionic/blob/d3ebc2f7c49a9893b114124d4a6b315f3a328764/libc/include/sys/auxv.h
+ // https://github.com/picolibc/picolibc/blob/7a8a58aeaa5946cb662577a518051091b691af3a/newlib/libc/picolib/getauxval.c
+ // https://github.com/rust-lang/libc/blob/0.2.139/src/unix/linux_like/linux/gnu/mod.rs#L1201
+ // https://github.com/rust-lang/libc/blob/0.2.139/src/unix/linux_like/linux/musl/mod.rs#L744
+ // https://github.com/rust-lang/libc/blob/0.2.139/src/unix/linux_like/android/b64/mod.rs#L333
+ pub(crate) fn getauxval(type_: c_ulong) -> c_ulong;
+
+ // Defined in sys/system_properties.h.
+ // https://github.com/aosp-mirror/platform_bionic/blob/d3ebc2f7c49a9893b114124d4a6b315f3a328764/libc/include/sys/system_properties.h
+ // https://github.com/rust-lang/libc/blob/0.2.139/src/unix/linux_like/android/mod.rs#L3471
+ #[cfg(all(target_arch = "aarch64", target_os = "android"))]
+ pub(crate) fn __system_property_get(name: *const c_char, value: *mut c_char) -> c_int;
+ }
+
+ // https://github.com/torvalds/linux/blob/v6.1/include/uapi/linux/auxvec.h
+ #[cfg(any(test, target_arch = "aarch64"))]
+ pub(crate) const AT_HWCAP: c_ulong = 16;
+ #[cfg(any(test, target_arch = "powerpc64"))]
+ pub(crate) const AT_HWCAP2: c_ulong = 26;
+
+ // Defined in sys/system_properties.h.
+ // https://github.com/aosp-mirror/platform_bionic/blob/d3ebc2f7c49a9893b114124d4a6b315f3a328764/libc/include/sys/system_properties.h
+ #[cfg(all(target_arch = "aarch64", target_os = "android"))]
+ pub(crate) const PROP_VALUE_MAX: c_int = 92;
+ }
+
+ pub(super) fn getauxval(type_: ffi::c_ulong) -> ffi::c_ulong {
+ #[cfg(all(target_arch = "aarch64", target_os = "android"))]
+ {
+ // Samsung Exynos 9810 has a bug that big and little cores have different
+ // ISAs. And on older Android (pre-9), the kernel incorrectly reports
+ // that features available only on some cores are available on all cores.
+ // https://reviews.llvm.org/D114523
+ let mut arch = [0_u8; ffi::PROP_VALUE_MAX as usize];
+ // SAFETY: we've passed a valid C string and a buffer with max length.
+ let len = unsafe {
+ ffi::__system_property_get(
+ b"ro.arch\0".as_ptr().cast::<ffi::c_char>(),
+ arch.as_mut_ptr().cast::<ffi::c_char>(),
+ )
+ };
+ // On Exynos, ro.arch is not available on Android 12+, but it is fine
+ // because Android 9+ includes the fix.
+ if len > 0 && arch.starts_with(b"exynos9810") {
+ return 0;
+ }
+ }
+
+ // SAFETY: `getauxval` is thread-safe. See also the module level docs.
+ unsafe { ffi::getauxval(type_) }
+ }
+}
+#[cfg(target_os = "freebsd")]
+mod os {
+ // core::ffi::c_* (except c_void) requires Rust 1.64, libc will soon require Rust 1.47
+ #[cfg_attr(test, allow(dead_code))]
+ pub(super) mod ffi {
+ pub(crate) use super::super::c_types::{c_int, c_ulong, c_void};
+
+ extern "C" {
+ // Defined in sys/auxv.h.
+ // https://man.freebsd.org/elf_aux_info(3)
+ // https://github.com/freebsd/freebsd-src/blob/deb63adf945d446ed91a9d84124c71f15ae571d1/sys/sys/auxv.h
+ pub(crate) fn elf_aux_info(aux: c_int, buf: *mut c_void, buf_len: c_int) -> c_int;
+ }
+
+ // Defined in sys/elf_common.h.
+ // https://github.com/freebsd/freebsd-src/blob/deb63adf945d446ed91a9d84124c71f15ae571d1/sys/sys/elf_common.h
+ #[cfg(any(test, target_arch = "aarch64"))]
+ pub(crate) const AT_HWCAP: c_int = 25;
+ #[cfg(any(test, target_arch = "powerpc64"))]
+ pub(crate) const AT_HWCAP2: c_int = 26;
+ }
+
+ pub(super) fn getauxval(aux: ffi::c_int) -> ffi::c_ulong {
+ #[allow(clippy::cast_possible_wrap, clippy::cast_possible_truncation)]
+ const OUT_LEN: ffi::c_int = core::mem::size_of::<ffi::c_ulong>() as ffi::c_int;
+ let mut out: ffi::c_ulong = 0;
+ // SAFETY:
+ // - the pointer is valid because we got it from a reference.
+ // - `OUT_LEN` is the same as the size of `out`.
+ // - `elf_aux_info` is thread-safe.
+ unsafe {
+ let res = ffi::elf_aux_info(
+ aux,
+ (&mut out as *mut ffi::c_ulong).cast::<ffi::c_void>(),
+ OUT_LEN,
+ );
+ // If elf_aux_info fails, `out` will be left at zero (which is the proper default value).
+ debug_assert!(res == 0 || out == 0);
+ }
+ out
+ }
+}
+
+// Basically, Linux and FreeBSD use the same hwcap values.
+// FreeBSD supports a subset of the hwcap values supported by Linux.
+use arch::_detect;
+#[cfg(target_arch = "aarch64")]
+mod arch {
+ use super::{ffi, os, CpuInfo};
+
+ // Linux
+ // https://github.com/torvalds/linux/blob/1c41041124bd14dd6610da256a3da4e5b74ce6b1/arch/arm64/include/uapi/asm/hwcap.h
+ // FreeBSD
+ // Defined in machine/elf.h.
+ // https://github.com/freebsd/freebsd-src/blob/deb63adf945d446ed91a9d84124c71f15ae571d1/sys/arm64/include/elf.h
+ // available on FreeBSD 13.0+ and 12.2+
+ // https://github.com/freebsd/freebsd-src/blob/release/13.0.0/sys/arm64/include/elf.h
+ // https://github.com/freebsd/freebsd-src/blob/release/12.2.0/sys/arm64/include/elf.h
+ pub(super) const HWCAP_ATOMICS: ffi::c_ulong = 1 << 8;
+ pub(super) const HWCAP_USCAT: ffi::c_ulong = 1 << 25;
+ #[cfg(any(target_os = "linux", target_os = "android"))]
+ #[cfg(target_pointer_width = "64")]
+ #[cfg(test)]
+ pub(super) const HWCAP2_LRCPC3: ffi::c_ulong = 1 << 46;
+ #[cfg(any(target_os = "linux", target_os = "android"))]
+ #[cfg(target_pointer_width = "64")]
+ #[cfg(test)]
+ pub(super) const HWCAP2_LSE128: ffi::c_ulong = 1 << 47;
+
+ #[cold]
+ pub(super) fn _detect(info: &mut CpuInfo) {
+ let hwcap = os::getauxval(ffi::AT_HWCAP);
+
+ if hwcap & HWCAP_ATOMICS != 0 {
+ info.set(CpuInfo::HAS_LSE);
+ }
+ if hwcap & HWCAP_USCAT != 0 {
+ info.set(CpuInfo::HAS_LSE2);
+ }
+ #[cfg(any(target_os = "linux", target_os = "android"))]
+ #[cfg(target_pointer_width = "64")]
+ #[cfg(test)]
+ {
+ let hwcap2 = os::getauxval(ffi::AT_HWCAP2);
+ if hwcap2 & HWCAP2_LRCPC3 != 0 {
+ info.set(CpuInfo::HAS_RCPC3);
+ }
+ if hwcap2 & HWCAP2_LSE128 != 0 {
+ info.set(CpuInfo::HAS_LSE128);
+ }
+ }
+ }
+}
+#[cfg(target_arch = "powerpc64")]
+mod arch {
+ use super::{ffi, os, CpuInfo};
+
+ // Linux
+ // https://github.com/torvalds/linux/blob/v6.1/arch/powerpc/include/uapi/asm/cputable.h
+ // FreeBSD
+ // Defined in machine/cpu.h.
+ // https://github.com/freebsd/freebsd-src/blob/deb63adf945d446ed91a9d84124c71f15ae571d1/sys/powerpc/include/cpu.h
+ // available on FreeBSD 11.0+
+ // https://github.com/freebsd/freebsd-src/commit/b0bf7fcd298133457991b27625bbed766e612730
+ pub(super) const PPC_FEATURE2_ARCH_2_07: ffi::c_ulong = 0x80000000;
+
+ #[cold]
+ pub(super) fn _detect(info: &mut CpuInfo) {
+ let hwcap2 = os::getauxval(ffi::AT_HWCAP2);
+
+ // power8
+ if hwcap2 & PPC_FEATURE2_ARCH_2_07 != 0 {
+ info.set(CpuInfo::HAS_QUADWORD_ATOMICS);
+ }
+ }
+}
+
+#[allow(
+ clippy::alloc_instead_of_core,
+ clippy::std_instead_of_alloc,
+ clippy::std_instead_of_core,
+ clippy::undocumented_unsafe_blocks,
+ clippy::wildcard_imports
+)]
+#[cfg(test)]
+mod tests {
+ use super::*;
+
+ #[cfg(any(target_os = "linux", target_os = "android"))]
+ #[cfg(target_pointer_width = "64")]
+ #[test]
+ fn test_linux_like() {
+ use c_types::*;
+ use core::{arch::asm, mem};
+ use std::vec;
+ use test_helper::{libc, sys};
+
+ // Linux kernel 6.4 has added a way to read auxv without depending on either libc or mrs trap.
+ // https://github.com/torvalds/linux/commit/ddc65971bb677aa9f6a4c21f76d3133e106f88eb
+ //
+ // This is currently used only for testing.
+ fn getauxval_pr_get_auxv(type_: ffi::c_ulong) -> Result<ffi::c_ulong, c_int> {
+ #[cfg(target_arch = "aarch64")]
+ unsafe fn prctl_get_auxv(out: *mut c_void, len: usize) -> Result<usize, c_int> {
+ let r: i64;
+ unsafe {
+ asm!(
+ "svc 0",
+ in("x8") sys::__NR_prctl as u64,
+ inout("x0") sys::PR_GET_AUXV as u64 => r,
+ in("x1") ptr_reg!(out),
+ in("x2") len as u64,
+ // arg4 and arg5 must be zero.
+ in("x3") 0_u64,
+ in("x4") 0_u64,
+ options(nostack, preserves_flags)
+ );
+ }
+ #[allow(clippy::cast_possible_truncation, clippy::cast_sign_loss)]
+ if (r as c_int) < 0 {
+ Err(r as c_int)
+ } else {
+ Ok(r as usize)
+ }
+ }
+ #[cfg(target_arch = "powerpc64")]
+ unsafe fn prctl_get_auxv(out: *mut c_void, len: usize) -> Result<usize, c_int> {
+ let r: i64;
+ unsafe {
+ asm!(
+ "sc",
+ "bns+ 2f",
+ "neg %r3, %r3",
+ "2:",
+ inout("r0") sys::__NR_prctl as u64 => _,
+ inout("r3") sys::PR_GET_AUXV as u64 => r,
+ inout("r4") ptr_reg!(out) => _,
+ inout("r5") len as u64 => _,
+ // arg4 and arg5 must be zero.
+ inout("r6") 0_u64 => _,
+ inout("r7") 0_u64 => _,
+ out("r8") _,
+ out("r9") _,
+ out("r10") _,
+ out("r11") _,
+ out("r12") _,
+ out("cr0") _,
+ options(nostack, preserves_flags)
+ );
+ }
+ #[allow(clippy::cast_possible_truncation, clippy::cast_sign_loss)]
+ if (r as c_int) < 0 {
+ Err(r as c_int)
+ } else {
+ Ok(r as usize)
+ }
+ }
+
+ let mut auxv = vec![unsafe { mem::zeroed::<sys::Elf64_auxv_t>() }; 38];
+
+ let old_len = auxv.len() * mem::size_of::<sys::Elf64_auxv_t>();
+
+ // SAFETY:
+ // - `out_len` does not exceed the size of `auxv`.
+ let _len = unsafe { prctl_get_auxv(auxv.as_mut_ptr().cast::<c_void>(), old_len)? };
+
+ for aux in &auxv {
+ if aux.a_type == type_ {
+ // SAFETY: aux.a_un is #[repr(C)] union and all fields have
+ // the same size and can be safely transmuted to integers.
+ return Ok(unsafe { aux.a_un.a_val });
+ }
+ }
+ Err(0)
+ }
+
+ unsafe {
+ let mut u = mem::zeroed();
+ assert_eq!(libc::uname(&mut u), 0);
+ let release = std::ffi::CStr::from_ptr(u.release.as_ptr());
+ let release = core::str::from_utf8(release.to_bytes()).unwrap();
+ let mut digits = release.split('.');
+ let major = digits.next().unwrap().parse::<u32>().unwrap();
+ let minor = digits.next().unwrap().parse::<u32>().unwrap();
+ if (major, minor) < (6, 4) {
+ std::eprintln!("kernel version: {major}.{minor} (no pr_get_auxv)");
+ assert_eq!(getauxval_pr_get_auxv(ffi::AT_HWCAP).unwrap_err(), -22);
+ assert_eq!(getauxval_pr_get_auxv(ffi::AT_HWCAP2).unwrap_err(), -22);
+ } else {
+ std::eprintln!("kernel version: {major}.{minor} (has pr_get_auxv)");
+ assert_eq!(
+ os::getauxval(ffi::AT_HWCAP),
+ getauxval_pr_get_auxv(ffi::AT_HWCAP).unwrap()
+ );
+ assert_eq!(
+ os::getauxval(ffi::AT_HWCAP2),
+ getauxval_pr_get_auxv(ffi::AT_HWCAP2).unwrap()
+ );
+ }
+ }
+ }
+
+ #[allow(clippy::cast_sign_loss)]
+ #[cfg(all(target_arch = "aarch64", target_os = "android"))]
+ #[test]
+ fn test_android() {
+ unsafe {
+ let mut arch = [1; ffi::PROP_VALUE_MAX as usize];
+ let len = ffi::__system_property_get(
+ b"ro.arch\0".as_ptr().cast::<ffi::c_char>(),
+ arch.as_mut_ptr().cast::<ffi::c_char>(),
+ );
+ assert!(len >= 0);
+ std::eprintln!("len={}", len);
+ std::eprintln!("arch={:?}", arch);
+ std::eprintln!(
+ "arch={:?}",
+ core::str::from_utf8(core::slice::from_raw_parts(arch.as_ptr(), len as usize))
+ .unwrap()
+ );
+ }
+ }
+
+ #[allow(clippy::cast_possible_wrap)]
+ #[cfg(target_os = "freebsd")]
+ #[test]
+ fn test_freebsd() {
+ use c_types::*;
+ use core::{arch::asm, mem, ptr};
+ use test_helper::sys;
+
+ // This is almost equivalent to what elf_aux_info does.
+ // https://man.freebsd.org/elf_aux_info(3)
+ // On FreeBSD, [aarch64 support is available on FreeBSD 11.0+](https://www.freebsd.org/releases/11.0R/relnotes/#hardware-arm),
+ // but elf_aux_info is available on FreeBSD 12.0+ and 11.4+:
+ // https://github.com/freebsd/freebsd-src/commit/0b08ae2120cdd08c20a2b806e2fcef4d0a36c470
+ // https://github.com/freebsd/freebsd-src/blob/release/11.4.0/sys/sys/auxv.h
+ // so use sysctl instead of elf_aux_info.
+ // Note that FreeBSD 11 (11.4) was EoL on 2021-09-30, and FreeBSD 11.3 was EoL on 2020-09-30:
+ // https://www.freebsd.org/security/unsupported
+ //
+ // std_detect uses this way, but it appears to be somewhat incorrect
+ // (the type of arg4 of sysctl, auxv is smaller than AT_COUNT, etc.).
+ // https://github.com/rust-lang/stdarch/blob/a0c30f3e3c75adcd6ee7efc94014ebcead61c507/crates/std_detect/src/detect/os/freebsd/auxvec.rs#L52
+ //
+ // This is currently used only for testing.
+ // If you want us to use this implementation for compatibility with the older FreeBSD
+ // version that came to EoL a few years ago, please open an issue.
+ fn getauxval_sysctl_libc(type_: ffi::c_int) -> ffi::c_ulong {
+ let mut auxv: [sys::Elf64_Auxinfo; sys::AT_COUNT as usize] = unsafe { mem::zeroed() };
+
+ let mut len = core::mem::size_of_val(&auxv) as c_size_t;
+
+ // SAFETY: calling getpid is safe.
+ let pid = unsafe { sys::getpid() };
+ let mib = [
+ sys::CTL_KERN as c_int,
+ sys::KERN_PROC as c_int,
+ sys::KERN_PROC_AUXV as c_int,
+ pid,
+ ];
+
+ #[allow(clippy::cast_possible_truncation)]
+ // SAFETY:
+ // - `mib.len()` does not exceed the size of `mib`.
+ // - `len` does not exceed the size of `auxv`.
+ // - `sysctl` is thread-safe.
+ let res = unsafe {
+ sys::sysctl(
+ mib.as_ptr(),
+ mib.len() as c_uint,
+ auxv.as_mut_ptr().cast::<c_void>(),
+ &mut len,
+ ptr::null_mut(),
+ 0,
+ )
+ };
+
+ if res != -1 {
+ for aux in &auxv {
+ if aux.a_type == type_ as c_long {
+ // SAFETY: aux.a_un is #[repr(C)] union and all fields have
+ // the same size and can be safely transmuted to integers.
+ return unsafe { aux.a_un.a_val as c_ulong };
+ }
+ }
+ }
+ 0
+ }
+ // Similar to the above, but call syscall using asm instead of libc.
+ // Note that FreeBSD does not guarantee the stability of raw syscall as
+ // much as Linux does (It may actually be stable enough, though:
+ // https://lists.llvm.org/pipermail/llvm-dev/2019-June/133393.html,
+ // https://github.com/ziglang/zig/issues/16590).
+ //
+ // This is currently used only for testing.
+ fn getauxval_sysctl_asm_syscall(type_: ffi::c_int) -> Result<ffi::c_ulong, c_int> {
+ #[allow(non_camel_case_types)]
+ type pid_t = c_int;
+
+ // https://github.com/freebsd/freebsd-src/blob/9888a79adad22ba06b5aff17d05abac0029c537a/lib/libc/aarch64/SYS.h
+ // https://github.com/golang/go/blob/4badad8d477ffd7a6b762c35bc69aed82faface7/src/syscall/asm_freebsd_arm64.s
+ #[cfg(target_arch = "aarch64")]
+ #[inline]
+ fn getpid() -> pid_t {
+ #[allow(clippy::cast_possible_truncation)]
+ // SAFETY: calling getpid is safe.
+ unsafe {
+ let n = sys::SYS_getpid;
+ let r: i64;
+ asm!(
+ "svc 0",
+ in("x8") n as u64,
+ out("x0") r,
+ options(nostack, readonly),
+ );
+ r as pid_t
+ }
+ }
+ #[cfg(target_arch = "aarch64")]
+ #[inline]
+ unsafe fn sysctl(
+ name: *const c_int,
+ name_len: c_uint,
+ old_p: *mut c_void,
+ old_len_p: *mut c_size_t,
+ new_p: *const c_void,
+ new_len: c_size_t,
+ ) -> Result<c_int, c_int> {
+ #[allow(clippy::cast_possible_truncation)]
+ // SAFETY: the caller must uphold the safety contract.
+ unsafe {
+ let mut n = sys::SYS___sysctl as u64;
+ let r: i64;
+ asm!(
+ "svc 0",
+ "b.cc 2f",
+ "mov x8, x0",
+ "mov x0, #-1",
+ "2:",
+ inout("x8") n,
+ inout("x0") ptr_reg!(name) => r,
+ inout("x1") name_len as u64 => _,
+ in("x2") ptr_reg!(old_p),
+ in("x3") ptr_reg!(old_len_p),
+ in("x4") ptr_reg!(new_p),
+ in("x5") new_len as u64,
+ options(nostack),
+ );
+ if r as c_int == -1 {
+ Err(n as c_int)
+ } else {
+ Ok(r as c_int)
+ }
+ }
+ }
+
+ // https://github.com/freebsd/freebsd-src/blob/9888a79adad22ba06b5aff17d05abac0029c537a/lib/libc/powerpc64/SYS.h
+ #[cfg(target_arch = "powerpc64")]
+ #[inline]
+ fn getpid() -> pid_t {
+ #[allow(clippy::cast_possible_truncation)]
+ // SAFETY: calling getpid is safe.
+ unsafe {
+ let n = sys::SYS_getpid;
+ let r: i64;
+ asm!(
+ "sc",
+ inout("r0") n as u64 => _,
+ out("r3") r,
+ out("r4") _,
+ out("r5") _,
+ out("r6") _,
+ out("r7") _,
+ out("r8") _,
+ out("r9") _,
+ out("r10") _,
+ out("r11") _,
+ out("r12") _,
+ out("cr0") _,
+ options(nostack, preserves_flags, readonly),
+ );
+ r as pid_t
+ }
+ }
+ #[cfg(target_arch = "powerpc64")]
+ #[inline]
+ unsafe fn sysctl(
+ name: *const c_int,
+ name_len: c_uint,
+ old_p: *mut c_void,
+ old_len_p: *mut c_size_t,
+ new_p: *const c_void,
+ new_len: c_size_t,
+ ) -> Result<c_int, c_int> {
+ #[allow(clippy::cast_possible_truncation)]
+ // SAFETY: the caller must uphold the safety contract.
+ unsafe {
+ let mut n = sys::SYS___sysctl as u64;
+ let r: i64;
+ asm!(
+ "sc",
+ "bns+ 2f",
+ "mr %r0, %r3",
+ "li %r3, -1",
+ "2:",
+ inout("r0") n,
+ inout("r3") ptr_reg!(name) => r,
+ inout("r4") name_len as u64 => _,
+ inout("r5") ptr_reg!(old_p) => _,
+ inout("r6") ptr_reg!(old_len_p) => _,
+ inout("r7") ptr_reg!(new_p) => _,
+ inout("r8") new_len as u64 => _,
+ out("r9") _,
+ out("r10") _,
+ out("r11") _,
+ out("r12") _,
+ out("cr0") _,
+ options(nostack, preserves_flags)
+ );
+ if r as c_int == -1 {
+ Err(n as c_int)
+ } else {
+ Ok(r as c_int)
+ }
+ }
+ }
+
+ let mut auxv: [sys::Elf64_Auxinfo; sys::AT_COUNT as usize] = unsafe { mem::zeroed() };
+
+ let mut len = core::mem::size_of_val(&auxv) as c_size_t;
+
+ let pid = getpid();
+ let mib = [
+ sys::CTL_KERN as c_int,
+ sys::KERN_PROC as c_int,
+ sys::KERN_PROC_AUXV as c_int,
+ pid,
+ ];
+
+ #[allow(clippy::cast_possible_truncation)]
+ // SAFETY:
+ // - `mib.len()` does not exceed the size of `mib`.
+ // - `len` does not exceed the size of `auxv`.
+ // - `sysctl` is thread-safe.
+ unsafe {
+ sysctl(
+ mib.as_ptr(),
+ mib.len() as c_uint,
+ auxv.as_mut_ptr().cast::<c_void>(),
+ &mut len,
+ ptr::null_mut(),
+ 0,
+ )?;
+ }
+
+ for aux in &auxv {
+ if aux.a_type == type_ as c_long {
+ // SAFETY: aux.a_un is #[repr(C)] union and all fields have
+ // the same size and can be safely transmuted to integers.
+ return Ok(unsafe { aux.a_un.a_val as c_ulong });
+ }
+ }
+ Err(0)
+ }
+
+ assert_eq!(os::getauxval(ffi::AT_HWCAP), getauxval_sysctl_libc(ffi::AT_HWCAP));
+ assert_eq!(os::getauxval(ffi::AT_HWCAP2), getauxval_sysctl_libc(ffi::AT_HWCAP2));
+ assert_eq!(
+ os::getauxval(ffi::AT_HWCAP),
+ getauxval_sysctl_asm_syscall(ffi::AT_HWCAP).unwrap()
+ );
+ assert_eq!(
+ os::getauxval(ffi::AT_HWCAP2),
+ // AT_HWCAP2 is only available on FreeBSD 13+, at least for aarch64.
+ getauxval_sysctl_asm_syscall(ffi::AT_HWCAP2).unwrap_or(0)
+ );
+ }
+
+ // Static assertions for FFI bindings.
+ // This checks that FFI bindings defined in this crate, FFI bindings defined
+ // in libc, and FFI bindings generated for the platform's latest header file
+ // using bindgen have compatible signatures (or the same values if constants).
+ // Since this is static assertion, we can detect problems with
+ // `cargo check --tests --target <target>` run in CI (via TESTS=1 build.sh)
+ // without actually running tests on these platforms.
+ // See also tools/codegen/src/ffi.rs.
+ // TODO(codegen): auto-generate this test
+ #[allow(
+ clippy::cast_possible_wrap,
+ clippy::cast_sign_loss,
+ clippy::cast_possible_truncation,
+ clippy::no_effect_underscore_binding
+ )]
+ const _: fn() = || {
+ use test_helper::{libc, sys};
+ #[cfg(not(target_os = "freebsd"))]
+ type AtType = ffi::c_ulong;
+ #[cfg(target_os = "freebsd")]
+ type AtType = ffi::c_int;
+ #[cfg(any(target_os = "linux", target_os = "android"))]
+ {
+ let mut _getauxval: unsafe extern "C" fn(ffi::c_ulong) -> ffi::c_ulong = ffi::getauxval;
+ _getauxval = libc::getauxval;
+ _getauxval = sys::getauxval;
+ }
+ #[cfg(all(target_arch = "aarch64", target_os = "android"))]
+ {
+ let mut ___system_property_get: unsafe extern "C" fn(
+ *const ffi::c_char,
+ *mut ffi::c_char,
+ ) -> ffi::c_int = ffi::__system_property_get;
+ ___system_property_get = libc::__system_property_get;
+ ___system_property_get = sys::__system_property_get;
+ static_assert!(ffi::PROP_VALUE_MAX == libc::PROP_VALUE_MAX);
+ static_assert!(ffi::PROP_VALUE_MAX == sys::PROP_VALUE_MAX as ffi::c_int);
+ }
+ #[cfg(target_os = "freebsd")]
+ {
+ let mut _elf_aux_info: unsafe extern "C" fn(
+ ffi::c_int,
+ *mut ffi::c_void,
+ ffi::c_int,
+ ) -> ffi::c_int = ffi::elf_aux_info;
+ _elf_aux_info = libc::elf_aux_info;
+ _elf_aux_info = sys::elf_aux_info;
+ }
+ #[cfg(not(target_os = "freebsd"))] // libc doesn't have this on FreeBSD
+ static_assert!(ffi::AT_HWCAP == libc::AT_HWCAP);
+ static_assert!(ffi::AT_HWCAP == sys::AT_HWCAP as AtType);
+ #[cfg(not(target_os = "freebsd"))] // libc doesn't have this on FreeBSD
+ static_assert!(ffi::AT_HWCAP2 == libc::AT_HWCAP2);
+ static_assert!(ffi::AT_HWCAP2 == sys::AT_HWCAP2 as AtType);
+ #[cfg(target_arch = "aarch64")]
+ {
+ // static_assert!(arch::HWCAP_ATOMICS == libc::HWCAP_ATOMICS); // libc doesn't have this
+ static_assert!(arch::HWCAP_ATOMICS == sys::HWCAP_ATOMICS as ffi::c_ulong);
+ // static_assert!(HWCAP_USCAT == libc::HWCAP_USCAT); // libc doesn't have this
+ static_assert!(arch::HWCAP_USCAT == sys::HWCAP_USCAT as ffi::c_ulong);
+ #[cfg(any(target_os = "linux", target_os = "android"))]
+ #[cfg(target_pointer_width = "64")]
+ {
+ // static_assert!(HWCAP2_LRCPC3 == libc::HWCAP2_LRCPC3); // libc doesn't have this
+ static_assert!(arch::HWCAP2_LRCPC3 == sys::HWCAP2_LRCPC3 as ffi::c_ulong);
+ // static_assert!(HWCAP2_LSE128 == libc::HWCAP2_LSE128); // libc doesn't have this
+ static_assert!(arch::HWCAP2_LSE128 == sys::HWCAP2_LSE128 as ffi::c_ulong);
+ }
+ }
+ #[cfg(target_arch = "powerpc64")]
+ {
+ // static_assert!(arch::PPC_FEATURE2_ARCH_2_07 == libc::PPC_FEATURE2_ARCH_2_07); // libc doesn't have this
+ static_assert!(
+ arch::PPC_FEATURE2_ARCH_2_07 == sys::PPC_FEATURE2_ARCH_2_07 as ffi::c_ulong
+ );
+ }
+ };
+}