Initial vendor packages

Signed-off-by: Valentin Popov <valentin@popov.link>

1 files changed, 713 insertions, 0 deletions

diff --git a/vendor/rustix/src/backend/libc/process/syscalls.rs b/vendor/rustix/src/backend/libc/process/syscalls.rs
new file mode 100644
index 0000000..46fd182
--- /dev/null
+++ b/vendor/rustix/src/backend/libc/process/syscalls.rs
@@ -0,0 +1,713 @@
+//! libc syscalls supporting `rustix::process`.
+
+#[cfg(any(freebsdlike, linux_kernel, target_os = "fuchsia"))]
+use super::types::RawCpuSet;
+use crate::backend::c;
+#[cfg(not(any(target_os = "wasi", target_os = "fuchsia")))]
+use crate::backend::conv::borrowed_fd;
+#[cfg(feature = "fs")]
+use crate::backend::conv::c_str;
+#[cfg(all(feature = "alloc", feature = "fs", not(target_os = "wasi")))]
+use crate::backend::conv::ret_discarded_char_ptr;
+#[cfg(not(any(
+    target_os = "espidf",
+    target_os = "fuchsia",
+    target_os = "redox",
+    target_os = "vita",
+    target_os = "wasi"
+)))]
+use crate::backend::conv::ret_infallible;
+#[cfg(not(target_os = "wasi"))]
+use crate::backend::conv::ret_pid_t;
+#[cfg(linux_kernel)]
+use crate::backend::conv::ret_u32;
+#[cfg(all(feature = "alloc", not(target_os = "wasi")))]
+use crate::backend::conv::ret_usize;
+use crate::backend::conv::{ret, ret_c_int};
+#[cfg(not(any(target_os = "wasi", target_os = "fuchsia")))]
+use crate::fd::BorrowedFd;
+#[cfg(target_os = "linux")]
+use crate::fd::{AsRawFd, OwnedFd, RawFd};
+#[cfg(feature = "fs")]
+use crate::ffi::CStr;
+#[cfg(feature = "fs")]
+use crate::fs::Mode;
+use crate::io;
+#[cfg(all(feature = "alloc", not(target_os = "wasi")))]
+use crate::process::Gid;
+#[cfg(not(target_os = "wasi"))]
+use crate::process::Pid;
+#[cfg(not(any(target_os = "espidf", target_os = "wasi")))]
+use crate::process::Signal;
+#[cfg(not(any(
+    target_os = "espidf",
+    target_os = "fuchsia",
+    target_os = "vita",
+    target_os = "wasi"
+)))]
+use crate::process::Uid;
+#[cfg(linux_kernel)]
+use crate::process::{Cpuid, MembarrierCommand, MembarrierQuery};
+#[cfg(not(any(target_os = "espidf", target_os = "vita", target_os = "wasi")))]
+use crate::process::{RawPid, WaitOptions, WaitStatus};
+#[cfg(not(any(
+    target_os = "espidf",
+    target_os = "fuchsia",
+    target_os = "redox",
+    target_os = "vita",
+    target_os = "wasi"
+)))]
+use crate::process::{Resource, Rlimit};
+#[cfg(not(any(
+    target_os = "espidf",
+    target_os = "redox",
+    target_os = "openbsd",
+    target_os = "vita",
+    target_os = "wasi"
+)))]
+use crate::process::{WaitId, WaitidOptions, WaitidStatus};
+use core::mem::MaybeUninit;
+#[cfg(target_os = "linux")]
+use {
+    super::super::conv::ret_owned_fd, crate::process::PidfdFlags, crate::process::PidfdGetfdFlags,
+};
+
+#[cfg(any(linux_kernel, target_os = "dragonfly"))]
+#[inline]
+pub(crate) fn sched_getcpu() -> usize {
+    let r = unsafe { libc::sched_getcpu() };
+    debug_assert!(r >= 0);
+    r as usize
+}
+
+#[cfg(feature = "fs")]
+#[cfg(not(target_os = "wasi"))]
+pub(crate) fn chdir(path: &CStr) -> io::Result<()> {
+    unsafe { ret(c::chdir(c_str(path))) }
+}
+
+#[cfg(not(any(target_os = "fuchsia", target_os = "wasi")))]
+pub(crate) fn fchdir(dirfd: BorrowedFd<'_>) -> io::Result<()> {
+    unsafe { ret(c::fchdir(borrowed_fd(dirfd))) }
+}
+
+#[cfg(feature = "fs")]
+#[cfg(not(any(target_os = "fuchsia", target_os = "wasi")))]
+pub(crate) fn chroot(path: &CStr) -> io::Result<()> {
+    unsafe { ret(c::chroot(c_str(path))) }
+}
+
+#[cfg(all(feature = "alloc", feature = "fs"))]
+#[cfg(not(target_os = "wasi"))]
+pub(crate) fn getcwd(buf: &mut [MaybeUninit<u8>]) -> io::Result<()> {
+    unsafe { ret_discarded_char_ptr(c::getcwd(buf.as_mut_ptr().cast(), buf.len())) }
+}
+
+// The `membarrier` syscall has a third argument, but it's only used when
+// the `flags` argument is `MEMBARRIER_CMD_FLAG_CPU`.
+#[cfg(linux_kernel)]
+syscall! {
+    fn membarrier_all(
+        cmd: c::c_int,
+        flags: c::c_uint
+    ) via SYS_membarrier -> c::c_int
+}
+
+#[cfg(linux_kernel)]
+pub(crate) fn membarrier_query() -> MembarrierQuery {
+    // glibc does not have a wrapper for `membarrier`; [the documentation]
+    // says to use `syscall`.
+    //
+    // [the documentation]: https://man7.org/linux/man-pages/man2/membarrier.2.html#NOTES
+    const MEMBARRIER_CMD_QUERY: u32 = 0;
+    unsafe {
+        match ret_u32(membarrier_all(MEMBARRIER_CMD_QUERY as i32, 0)) {
+            Ok(query) => MembarrierQuery::from_bits_retain(query),
+            Err(_) => MembarrierQuery::empty(),
+        }
+    }
+}
+
+#[cfg(linux_kernel)]
+pub(crate) fn membarrier(cmd: MembarrierCommand) -> io::Result<()> {
+    unsafe { ret(membarrier_all(cmd as i32, 0)) }
+}
+
+#[cfg(linux_kernel)]
+pub(crate) fn membarrier_cpu(cmd: MembarrierCommand, cpu: Cpuid) -> io::Result<()> {
+    const MEMBARRIER_CMD_FLAG_CPU: u32 = 1;
+
+    syscall! {
+        fn membarrier_cpu(
+            cmd: c::c_int,
+            flags: c::c_uint,
+            cpu_id: c::c_int
+        ) via SYS_membarrier -> c::c_int
+    }
+
+    unsafe {
+        ret(membarrier_cpu(
+            cmd as i32,
+            MEMBARRIER_CMD_FLAG_CPU,
+            bitcast!(cpu.as_raw()),
+        ))
+    }
+}
+
+#[cfg(not(target_os = "wasi"))]
+#[inline]
+#[must_use]
+pub(crate) fn getppid() -> Option<Pid> {
+    unsafe {
+        let pid: i32 = c::getppid();
+        Pid::from_raw(pid)
+    }
+}
+
+#[cfg(not(target_os = "wasi"))]
+#[inline]
+pub(crate) fn getpgid(pid: Option<Pid>) -> io::Result<Pid> {
+    unsafe {
+        let pgid = ret_pid_t(c::getpgid(Pid::as_raw(pid) as _))?;
+        Ok(Pid::from_raw_unchecked(pgid))
+    }
+}
+
+#[cfg(not(target_os = "wasi"))]
+#[inline]
+pub(crate) fn setpgid(pid: Option<Pid>, pgid: Option<Pid>) -> io::Result<()> {
+    unsafe { ret(c::setpgid(Pid::as_raw(pid) as _, Pid::as_raw(pgid) as _)) }
+}
+
+#[cfg(not(target_os = "wasi"))]
+#[inline]
+#[must_use]
+pub(crate) fn getpgrp() -> Pid {
+    unsafe {
+        let pgid = c::getpgrp();
+        Pid::from_raw_unchecked(pgid)
+    }
+}
+
+#[cfg(any(freebsdlike, linux_kernel, target_os = "fuchsia"))]
+#[inline]
+pub(crate) fn sched_getaffinity(pid: Option<Pid>, cpuset: &mut RawCpuSet) -> io::Result<()> {
+    unsafe {
+        ret(c::sched_getaffinity(
+            Pid::as_raw(pid) as _,
+            core::mem::size_of::<RawCpuSet>(),
+            cpuset,
+        ))
+    }
+}
+
+#[cfg(any(freebsdlike, linux_kernel, target_os = "fuchsia"))]
+#[inline]
+pub(crate) fn sched_setaffinity(pid: Option<Pid>, cpuset: &RawCpuSet) -> io::Result<()> {
+    unsafe {
+        ret(c::sched_setaffinity(
+            Pid::as_raw(pid) as _,
+            core::mem::size_of::<RawCpuSet>(),
+            cpuset,
+        ))
+    }
+}
+
+#[inline]
+pub(crate) fn sched_yield() {
+    unsafe {
+        let _ = c::sched_yield();
+    }
+}
+
+#[cfg(not(target_os = "wasi"))]
+#[cfg(feature = "fs")]
+#[inline]
+pub(crate) fn umask(mask: Mode) -> Mode {
+    unsafe { Mode::from_bits_retain(c::umask(mask.bits() as c::mode_t).into()) }
+}
+
+#[cfg(not(any(target_os = "fuchsia", target_os = "vita", target_os = "wasi")))]
+#[inline]
+pub(crate) fn nice(inc: i32) -> io::Result<i32> {
+    libc_errno::set_errno(libc_errno::Errno(0));
+    let r = unsafe { c::nice(inc) };
+    if libc_errno::errno().0 != 0 {
+        ret_c_int(r)
+    } else {
+        Ok(r)
+    }
+}
+
+#[cfg(not(any(
+    target_os = "espidf",
+    target_os = "fuchsia",
+    target_os = "vita",
+    target_os = "wasi"
+)))]
+#[inline]
+pub(crate) fn getpriority_user(uid: Uid) -> io::Result<i32> {
+    libc_errno::set_errno(libc_errno::Errno(0));
+    let r = unsafe { c::getpriority(c::PRIO_USER, uid.as_raw() as _) };
+    if libc_errno::errno().0 != 0 {
+        ret_c_int(r)
+    } else {
+        Ok(r)
+    }
+}
+
+#[cfg(not(any(
+    target_os = "espidf",
+    target_os = "fuchsia",
+    target_os = "vita",
+    target_os = "wasi"
+)))]
+#[inline]
+pub(crate) fn getpriority_pgrp(pgid: Option<Pid>) -> io::Result<i32> {
+    libc_errno::set_errno(libc_errno::Errno(0));
+    let r = unsafe { c::getpriority(c::PRIO_PGRP, Pid::as_raw(pgid) as _) };
+    if libc_errno::errno().0 != 0 {
+        ret_c_int(r)
+    } else {
+        Ok(r)
+    }
+}
+
+#[cfg(not(any(
+    target_os = "espidf",
+    target_os = "fuchsia",
+    target_os = "vita",
+    target_os = "wasi"
+)))]
+#[inline]
+pub(crate) fn getpriority_process(pid: Option<Pid>) -> io::Result<i32> {
+    libc_errno::set_errno(libc_errno::Errno(0));
+    let r = unsafe { c::getpriority(c::PRIO_PROCESS, Pid::as_raw(pid) as _) };
+    if libc_errno::errno().0 != 0 {
+        ret_c_int(r)
+    } else {
+        Ok(r)
+    }
+}
+
+#[cfg(not(any(
+    target_os = "espidf",
+    target_os = "fuchsia",
+    target_os = "vita",
+    target_os = "wasi"
+)))]
+#[inline]
+pub(crate) fn setpriority_user(uid: Uid, priority: i32) -> io::Result<()> {
+    unsafe { ret(c::setpriority(c::PRIO_USER, uid.as_raw() as _, priority)) }
+}
+
+#[cfg(not(any(
+    target_os = "espidf",
+    target_os = "fuchsia",
+    target_os = "vita",
+    target_os = "wasi"
+)))]
+#[inline]
+pub(crate) fn setpriority_pgrp(pgid: Option<Pid>, priority: i32) -> io::Result<()> {
+    unsafe {
+        ret(c::setpriority(
+            c::PRIO_PGRP,
+            Pid::as_raw(pgid) as _,
+            priority,
+        ))
+    }
+}
+
+#[cfg(not(any(
+    target_os = "espidf",
+    target_os = "fuchsia",
+    target_os = "vita",
+    target_os = "wasi"
+)))]
+#[inline]
+pub(crate) fn setpriority_process(pid: Option<Pid>, priority: i32) -> io::Result<()> {
+    unsafe {
+        ret(c::setpriority(
+            c::PRIO_PROCESS,
+            Pid::as_raw(pid) as _,
+            priority,
+        ))
+    }
+}
+
+#[cfg(not(any(
+    target_os = "espidf",
+    target_os = "fuchsia",
+    target_os = "redox",
+    target_os = "vita",
+    target_os = "wasi"
+)))]
+#[inline]
+pub(crate) fn getrlimit(limit: Resource) -> Rlimit {
+    let mut result = MaybeUninit::<c::rlimit>::uninit();
+    unsafe {
+        ret_infallible(c::getrlimit(limit as _, result.as_mut_ptr()));
+        rlimit_from_libc(result.assume_init())
+    }
+}
+
+#[cfg(not(any(
+    target_os = "espidf",
+    target_os = "fuchsia",
+    target_os = "redox",
+    target_os = "vita",
+    target_os = "wasi"
+)))]
+#[inline]
+pub(crate) fn setrlimit(limit: Resource, new: Rlimit) -> io::Result<()> {
+    let lim = rlimit_to_libc(new)?;
+    unsafe { ret(c::setrlimit(limit as _, &lim)) }
+}
+
+#[cfg(linux_kernel)]
+#[inline]
+pub(crate) fn prlimit(pid: Option<Pid>, limit: Resource, new: Rlimit) -> io::Result<Rlimit> {
+    let lim = rlimit_to_libc(new)?;
+    let mut result = MaybeUninit::<c::rlimit>::uninit();
+    unsafe {
+        ret(c::prlimit(
+            Pid::as_raw(pid),
+            limit as _,
+            &lim,
+            result.as_mut_ptr(),
+        ))?;
+        Ok(rlimit_from_libc(result.assume_init()))
+    }
+}
+
+/// Convert a Rust [`Rlimit`] to a C `c::rlimit`.
+#[cfg(not(any(
+    target_os = "espidf",
+    target_os = "fuchsia",
+    target_os = "redox",
+    target_os = "vita",
+    target_os = "wasi"
+)))]
+fn rlimit_from_libc(lim: c::rlimit) -> Rlimit {
+    let current = if lim.rlim_cur == c::RLIM_INFINITY {
+        None
+    } else {
+        Some(lim.rlim_cur.try_into().unwrap())
+    };
+    let maximum = if lim.rlim_max == c::RLIM_INFINITY {
+        None
+    } else {
+        Some(lim.rlim_max.try_into().unwrap())
+    };
+    Rlimit { current, maximum }
+}
+
+/// Convert a C `c::rlimit` to a Rust `Rlimit`.
+#[cfg(not(any(
+    target_os = "espidf",
+    target_os = "fuchsia",
+    target_os = "redox",
+    target_os = "vita",
+    target_os = "wasi"
+)))]
+fn rlimit_to_libc(lim: Rlimit) -> io::Result<c::rlimit> {
+    let Rlimit { current, maximum } = lim;
+    let rlim_cur = match current {
+        Some(r) => r.try_into().map_err(|_e| io::Errno::INVAL)?,
+        None => c::RLIM_INFINITY as _,
+    };
+    let rlim_max = match maximum {
+        Some(r) => r.try_into().map_err(|_e| io::Errno::INVAL)?,
+        None => c::RLIM_INFINITY as _,
+    };
+    Ok(c::rlimit { rlim_cur, rlim_max })
+}
+
+#[cfg(not(any(target_os = "espidf", target_os = "vita", target_os = "wasi")))]
+#[inline]
+pub(crate) fn wait(waitopts: WaitOptions) -> io::Result<Option<(Pid, WaitStatus)>> {
+    _waitpid(!0, waitopts)
+}
+
+#[cfg(not(any(target_os = "espidf", target_os = "vita", target_os = "wasi")))]
+#[inline]
+pub(crate) fn waitpid(
+    pid: Option<Pid>,
+    waitopts: WaitOptions,
+) -> io::Result<Option<(Pid, WaitStatus)>> {
+    _waitpid(Pid::as_raw(pid), waitopts)
+}
+
+#[cfg(not(any(target_os = "espidf", target_os = "vita", target_os = "wasi")))]
+#[inline]
+pub(crate) fn waitpgid(pgid: Pid, waitopts: WaitOptions) -> io::Result<Option<(Pid, WaitStatus)>> {
+    _waitpid(-pgid.as_raw_nonzero().get(), waitopts)
+}
+
+#[cfg(not(any(target_os = "espidf", target_os = "vita", target_os = "wasi")))]
+#[inline]
+pub(crate) fn _waitpid(
+    pid: RawPid,
+    waitopts: WaitOptions,
+) -> io::Result<Option<(Pid, WaitStatus)>> {
+    unsafe {
+        let mut status: c::c_int = 0;
+        let pid = ret_c_int(c::waitpid(pid as _, &mut status, waitopts.bits() as _))?;
+        Ok(Pid::from_raw(pid).map(|pid| (pid, WaitStatus::new(status as _))))
+    }
+}
+
+#[cfg(not(any(
+    target_os = "espidf",
+    target_os = "redox",
+    target_os = "openbsd",
+    target_os = "vita",
+    target_os = "wasi"
+)))]
+#[inline]
+pub(crate) fn waitid(id: WaitId<'_>, options: WaitidOptions) -> io::Result<Option<WaitidStatus>> {
+    // Get the id to wait on.
+    match id {
+        WaitId::All => _waitid_all(options),
+        WaitId::Pid(pid) => _waitid_pid(pid, options),
+        WaitId::Pgid(pgid) => _waitid_pgid(pgid, options),
+        #[cfg(target_os = "linux")]
+        WaitId::PidFd(fd) => _waitid_pidfd(fd, options),
+        #[cfg(not(target_os = "linux"))]
+        WaitId::__EatLifetime(_) => unreachable!(),
+    }
+}
+
+#[cfg(not(any(
+    target_os = "espidf",
+    target_os = "redox",
+    target_os = "openbsd",
+    target_os = "vita",
+    target_os = "wasi"
+)))]
+#[inline]
+fn _waitid_all(options: WaitidOptions) -> io::Result<Option<WaitidStatus>> {
+    // `waitid` can return successfully without initializing the struct (no
+    // children found when using `WNOHANG`)
+    let mut status = MaybeUninit::<c::siginfo_t>::zeroed();
+    unsafe {
+        ret(c::waitid(
+            c::P_ALL,
+            0,
+            status.as_mut_ptr(),
+            options.bits() as _,
+        ))?
+    };
+
+    Ok(unsafe { cvt_waitid_status(status) })
+}
+
+#[cfg(not(any(
+    target_os = "espidf",
+    target_os = "redox",
+    target_os = "openbsd",
+    target_os = "vita",
+    target_os = "wasi"
+)))]
+#[inline]
+fn _waitid_pid(pid: Pid, options: WaitidOptions) -> io::Result<Option<WaitidStatus>> {
+    // `waitid` can return successfully without initializing the struct (no
+    // children found when using `WNOHANG`)
+    let mut status = MaybeUninit::<c::siginfo_t>::zeroed();
+    unsafe {
+        ret(c::waitid(
+            c::P_PID,
+            Pid::as_raw(Some(pid)) as _,
+            status.as_mut_ptr(),
+            options.bits() as _,
+        ))?
+    };
+
+    Ok(unsafe { cvt_waitid_status(status) })
+}
+
+#[cfg(not(any(
+    target_os = "espidf",
+    target_os = "redox",
+    target_os = "openbsd",
+    target_os = "vita",
+    target_os = "wasi"
+)))]
+#[inline]
+fn _waitid_pgid(pgid: Option<Pid>, options: WaitidOptions) -> io::Result<Option<WaitidStatus>> {
+    // `waitid` can return successfully without initializing the struct (no
+    // children found when using `WNOHANG`)
+    let mut status = MaybeUninit::<c::siginfo_t>::zeroed();
+    unsafe {
+        ret(c::waitid(
+            c::P_PGID,
+            Pid::as_raw(pgid) as _,
+            status.as_mut_ptr(),
+            options.bits() as _,
+        ))?
+    };
+
+    Ok(unsafe { cvt_waitid_status(status) })
+}
+
+#[cfg(target_os = "linux")]
+#[inline]
+fn _waitid_pidfd(fd: BorrowedFd<'_>, options: WaitidOptions) -> io::Result<Option<WaitidStatus>> {
+    // `waitid` can return successfully without initializing the struct (no
+    // children found when using `WNOHANG`)
+    let mut status = MaybeUninit::<c::siginfo_t>::zeroed();
+    unsafe {
+        ret(c::waitid(
+            c::P_PIDFD,
+            fd.as_raw_fd() as _,
+            status.as_mut_ptr(),
+            options.bits() as _,
+        ))?
+    };
+
+    Ok(unsafe { cvt_waitid_status(status) })
+}
+
+/// Convert a `siginfo_t` to a `WaitidStatus`.
+///
+/// # Safety
+///
+/// The caller must ensure that `status` is initialized and that `waitid`
+/// returned successfully.
+#[cfg(not(any(
+    target_os = "espidf",
+    target_os = "openbsd",
+    target_os = "redox",
+    target_os = "vita",
+    target_os = "wasi"
+)))]
+#[inline]
+unsafe fn cvt_waitid_status(status: MaybeUninit<c::siginfo_t>) -> Option<WaitidStatus> {
+    let status = status.assume_init();
+    // `si_pid` is supposedly the better way to check that the struct has been
+    // filled, e.g. the Linux manpage says about the `WNOHANG` case “zero out
+    // the si_pid field before the call and check for a nonzero value”.
+    // But e.g. NetBSD/OpenBSD don't have it exposed in the libc crate for now,
+    // and some platforms don't have it at all. For simplicity, always check
+    // `si_signo`. We have zero-initialized the whole struct, and all kernels
+    // should set `SIGCHLD` here.
+    if status.si_signo == 0 {
+        None
+    } else {
+        Some(WaitidStatus(status))
+    }
+}
+
+#[cfg(not(any(target_os = "redox", target_os = "wasi")))]
+#[inline]
+pub(crate) fn getsid(pid: Option<Pid>) -> io::Result<Pid> {
+    unsafe {
+        let pid = ret_pid_t(c::getsid(Pid::as_raw(pid) as _))?;
+        Ok(Pid::from_raw_unchecked(pid))
+    }
+}
+
+#[cfg(not(target_os = "wasi"))]
+#[inline]
+pub(crate) fn setsid() -> io::Result<Pid> {
+    unsafe {
+        let pid = ret_c_int(c::setsid())?;
+        Ok(Pid::from_raw_unchecked(pid))
+    }
+}
+
+#[cfg(not(any(target_os = "espidf", target_os = "wasi")))]
+#[inline]
+pub(crate) fn kill_process(pid: Pid, sig: Signal) -> io::Result<()> {
+    unsafe { ret(c::kill(pid.as_raw_nonzero().get(), sig as i32)) }
+}
+
+#[cfg(not(any(target_os = "espidf", target_os = "wasi")))]
+#[inline]
+pub(crate) fn kill_process_group(pid: Pid, sig: Signal) -> io::Result<()> {
+    unsafe {
+        ret(c::kill(
+            pid.as_raw_nonzero().get().wrapping_neg(),
+            sig as i32,
+        ))
+    }
+}
+
+#[cfg(not(any(target_os = "espidf", target_os = "wasi")))]
+#[inline]
+pub(crate) fn kill_current_process_group(sig: Signal) -> io::Result<()> {
+    unsafe { ret(c::kill(0, sig as i32)) }
+}
+
+#[cfg(not(any(target_os = "espidf", target_os = "wasi")))]
+pub(crate) fn test_kill_process(pid: Pid) -> io::Result<()> {
+    unsafe { ret(c::kill(pid.as_raw_nonzero().get(), 0)) }
+}
+
+#[cfg(not(any(target_os = "espidf", target_os = "wasi")))]
+#[inline]
+pub(crate) fn test_kill_process_group(pid: Pid) -> io::Result<()> {
+    unsafe { ret(c::kill(pid.as_raw_nonzero().get().wrapping_neg(), 0)) }
+}
+
+#[cfg(not(any(target_os = "espidf", target_os = "wasi")))]
+#[inline]
+pub(crate) fn test_kill_current_process_group() -> io::Result<()> {
+    unsafe { ret(c::kill(0, 0)) }
+}
+
+#[cfg(freebsdlike)]
+#[inline]
+pub(crate) unsafe fn procctl(
+    idtype: c::idtype_t,
+    id: c::id_t,
+    option: c::c_int,
+    data: *mut c::c_void,
+) -> io::Result<()> {
+    ret(c::procctl(idtype, id, option, data))
+}
+
+#[cfg(target_os = "linux")]
+pub(crate) fn pidfd_open(pid: Pid, flags: PidfdFlags) -> io::Result<OwnedFd> {
+    syscall! {
+        fn pidfd_open(
+            pid: c::pid_t,
+            flags: c::c_uint
+        ) via SYS_pidfd_open -> c::c_int
+    }
+    unsafe {
+        ret_owned_fd(pidfd_open(
+            pid.as_raw_nonzero().get(),
+            bitflags_bits!(flags),
+        ))
+    }
+}
+
+#[cfg(target_os = "linux")]
+pub(crate) fn pidfd_getfd(
+    pidfd: BorrowedFd<'_>,
+    targetfd: RawFd,
+    flags: PidfdGetfdFlags,
+) -> io::Result<OwnedFd> {
+    syscall! {
+        fn pidfd_getfd(
+            pidfd: c::c_int,
+            targetfd: c::c_int,
+            flags: c::c_uint
+        ) via SYS_pidfd_getfd -> c::c_int
+    }
+    unsafe {
+        ret_owned_fd(pidfd_getfd(
+            borrowed_fd(pidfd),
+            targetfd,
+            bitflags_bits!(flags),
+        ))
+    }
+}
+
+#[cfg(all(feature = "alloc", not(target_os = "wasi")))]
+pub(crate) fn getgroups(buf: &mut [Gid]) -> io::Result<usize> {
+    let len = buf.len().try_into().map_err(|_| io::Errno::NOMEM)?;
+
+    unsafe { ret_usize(c::getgroups(len, buf.as_mut_ptr().cast()) as isize) }
+}