| // 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/v6.1/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; |
| |
| #[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(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(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 |
| ); |
| } |
| }; |
| } |
