diff options
Diffstat (limited to 'vendor/rustix/src/imp/linux_raw/io/syscalls.rs')
| -rw-r--r-- | vendor/rustix/src/imp/linux_raw/io/syscalls.rs | 560 |
1 files changed, 560 insertions, 0 deletions
diff --git a/vendor/rustix/src/imp/linux_raw/io/syscalls.rs b/vendor/rustix/src/imp/linux_raw/io/syscalls.rs new file mode 100644 index 000000000..7857859de --- /dev/null +++ b/vendor/rustix/src/imp/linux_raw/io/syscalls.rs @@ -0,0 +1,560 @@ +//! linux_raw syscalls supporting `rustix::io`. +//! +//! # Safety +//! +//! See the `rustix::imp` module documentation for details. +#![allow(unsafe_code)] +#![allow(clippy::undocumented_unsafe_blocks)] + +use super::super::c; +#[cfg(target_pointer_width = "64")] +use super::super::conv::loff_t_from_u64; +use super::super::conv::{ + by_ref, c_int, c_uint, pass_usize, raw_fd, ret, ret_discarded_fd, ret_owned_fd, ret_usize, + slice, slice_mut, zero, +}; +#[cfg(target_pointer_width = "32")] +use super::super::conv::{hi, lo}; +use crate::fd::{AsFd, BorrowedFd, RawFd}; +use crate::io::{ + self, epoll, DupFlags, EventfdFlags, IoSlice, IoSliceMut, OwnedFd, PipeFlags, PollFd, + ReadWriteFlags, +}; +#[cfg(feature = "net")] +use crate::net::{RecvFlags, SendFlags}; +use core::cmp; +use core::mem::MaybeUninit; +use linux_raw_sys::general::{ + epoll_event, EPOLL_CTL_ADD, EPOLL_CTL_DEL, EPOLL_CTL_MOD, UIO_MAXIOV, +}; +use linux_raw_sys::ioctl::{BLKPBSZGET, BLKSSZGET, FIONBIO, FIONREAD, TIOCEXCL, TIOCNXCL}; +#[cfg(any(target_arch = "aarch64", target_arch = "riscv64"))] +use { + super::super::conv::{opt_ref, size_of}, + linux_raw_sys::general::{__kernel_timespec, sigset_t}, +}; + +#[inline] +pub(crate) fn read(fd: BorrowedFd<'_>, buf: &mut [u8]) -> io::Result<usize> { + let (buf_addr_mut, buf_len) = slice_mut(buf); + + unsafe { ret_usize(syscall!(__NR_read, fd, buf_addr_mut, buf_len)) } +} + +#[inline] +pub(crate) fn pread(fd: BorrowedFd<'_>, buf: &mut [u8], pos: u64) -> io::Result<usize> { + let (buf_addr_mut, buf_len) = slice_mut(buf); + + // <https://github.com/torvalds/linux/blob/fcadab740480e0e0e9fa9bd272acd409884d431a/arch/arm64/kernel/sys32.c#L75> + #[cfg(all( + target_pointer_width = "32", + any(target_arch = "arm", target_arch = "mips", target_arch = "power"), + ))] + unsafe { + ret_usize(syscall!( + __NR_pread64, + fd, + buf_addr_mut, + buf_len, + zero(), + hi(pos), + lo(pos) + )) + } + #[cfg(all( + target_pointer_width = "32", + not(any(target_arch = "arm", target_arch = "mips", target_arch = "power")), + ))] + unsafe { + ret_usize(syscall!( + __NR_pread64, + fd, + buf_addr_mut, + buf_len, + hi(pos), + lo(pos) + )) + } + #[cfg(target_pointer_width = "64")] + unsafe { + ret_usize(syscall!( + __NR_pread64, + fd, + buf_addr_mut, + buf_len, + loff_t_from_u64(pos) + )) + } +} + +#[inline] +pub(crate) fn readv(fd: BorrowedFd<'_>, bufs: &mut [IoSliceMut<'_>]) -> io::Result<usize> { + let (bufs_addr, bufs_len) = slice(&bufs[..cmp::min(bufs.len(), max_iov())]); + + unsafe { ret_usize(syscall!(__NR_readv, fd, bufs_addr, bufs_len)) } +} + +#[inline] +pub(crate) fn preadv( + fd: BorrowedFd<'_>, + bufs: &mut [IoSliceMut<'_>], + pos: u64, +) -> io::Result<usize> { + let (bufs_addr, bufs_len) = slice(&bufs[..cmp::min(bufs.len(), max_iov())]); + + #[cfg(target_pointer_width = "32")] + unsafe { + ret_usize(syscall!( + __NR_preadv, + fd, + bufs_addr, + bufs_len, + hi(pos), + lo(pos) + )) + } + #[cfg(target_pointer_width = "64")] + unsafe { + ret_usize(syscall!( + __NR_preadv, + fd, + bufs_addr, + bufs_len, + loff_t_from_u64(pos) + )) + } +} + +#[inline] +pub(crate) fn preadv2( + fd: BorrowedFd<'_>, + bufs: &mut [IoSliceMut<'_>], + pos: u64, + flags: ReadWriteFlags, +) -> io::Result<usize> { + let (bufs_addr, bufs_len) = slice(&bufs[..cmp::min(bufs.len(), max_iov())]); + + #[cfg(target_pointer_width = "32")] + unsafe { + ret_usize(syscall!( + __NR_preadv2, + fd, + bufs_addr, + bufs_len, + hi(pos), + lo(pos), + flags + )) + } + #[cfg(target_pointer_width = "64")] + unsafe { + ret_usize(syscall!( + __NR_preadv2, + fd, + bufs_addr, + bufs_len, + loff_t_from_u64(pos), + flags + )) + } +} + +#[inline] +pub(crate) fn write(fd: BorrowedFd<'_>, buf: &[u8]) -> io::Result<usize> { + let (buf_addr, buf_len) = slice(buf); + + unsafe { ret_usize(syscall_readonly!(__NR_write, fd, buf_addr, buf_len)) } +} + +#[inline] +pub(crate) fn pwrite(fd: BorrowedFd<'_>, buf: &[u8], pos: u64) -> io::Result<usize> { + let (buf_addr, buf_len) = slice(buf); + + // <https://github.com/torvalds/linux/blob/fcadab740480e0e0e9fa9bd272acd409884d431a/arch/arm64/kernel/sys32.c#L81-L83> + #[cfg(all( + target_pointer_width = "32", + any(target_arch = "arm", target_arch = "mips", target_arch = "power"), + ))] + unsafe { + ret_usize(syscall_readonly!( + __NR_pwrite64, + fd, + buf_addr, + buf_len, + zero(), + hi(pos), + lo(pos) + )) + } + #[cfg(all( + target_pointer_width = "32", + not(any(target_arch = "arm", target_arch = "mips", target_arch = "power")), + ))] + unsafe { + ret_usize(syscall_readonly!( + __NR_pwrite64, + fd, + buf_addr, + buf_len, + hi(pos), + lo(pos) + )) + } + #[cfg(target_pointer_width = "64")] + unsafe { + ret_usize(syscall_readonly!( + __NR_pwrite64, + fd, + buf_addr, + buf_len, + loff_t_from_u64(pos) + )) + } +} + +#[inline] +pub(crate) fn writev(fd: BorrowedFd<'_>, bufs: &[IoSlice<'_>]) -> io::Result<usize> { + let (bufs_addr, bufs_len) = slice(&bufs[..cmp::min(bufs.len(), max_iov())]); + + unsafe { ret_usize(syscall_readonly!(__NR_writev, fd, bufs_addr, bufs_len)) } +} + +#[inline] +pub(crate) fn pwritev(fd: BorrowedFd<'_>, bufs: &[IoSlice<'_>], pos: u64) -> io::Result<usize> { + let (bufs_addr, bufs_len) = slice(&bufs[..cmp::min(bufs.len(), max_iov())]); + + #[cfg(target_pointer_width = "32")] + unsafe { + ret_usize(syscall_readonly!( + __NR_pwritev, + fd, + bufs_addr, + bufs_len, + hi(pos), + lo(pos) + )) + } + #[cfg(target_pointer_width = "64")] + unsafe { + ret_usize(syscall_readonly!( + __NR_pwritev, + fd, + bufs_addr, + bufs_len, + loff_t_from_u64(pos) + )) + } +} + +#[inline] +pub(crate) fn pwritev2( + fd: BorrowedFd<'_>, + bufs: &[IoSlice<'_>], + pos: u64, + flags: ReadWriteFlags, +) -> io::Result<usize> { + let (bufs_addr, bufs_len) = slice(&bufs[..cmp::min(bufs.len(), max_iov())]); + + #[cfg(target_pointer_width = "32")] + unsafe { + ret_usize(syscall_readonly!( + __NR_pwritev2, + fd, + bufs_addr, + bufs_len, + hi(pos), + lo(pos), + flags + )) + } + #[cfg(target_pointer_width = "64")] + unsafe { + ret_usize(syscall_readonly!( + __NR_pwritev2, + fd, + bufs_addr, + bufs_len, + loff_t_from_u64(pos), + flags + )) + } +} + +/// The maximum number of buffers that can be passed into a vectored I/O system +/// call on the current platform. +const fn max_iov() -> usize { + UIO_MAXIOV as usize +} + +#[inline] +pub(crate) unsafe fn close(fd: RawFd) { + // See the documentation for [`io::close`] for why errors are ignored. + syscall_readonly!(__NR_close, raw_fd(fd)).decode_void(); +} + +#[inline] +pub(crate) fn eventfd(initval: u32, flags: EventfdFlags) -> io::Result<OwnedFd> { + unsafe { ret_owned_fd(syscall_readonly!(__NR_eventfd2, c_uint(initval), flags)) } +} + +#[inline] +pub(crate) fn ioctl_fionread(fd: BorrowedFd<'_>) -> io::Result<u64> { + unsafe { + let mut result = MaybeUninit::<c::c_int>::uninit(); + ret(syscall!(__NR_ioctl, fd, c_uint(FIONREAD), &mut result)) + .map(|()| result.assume_init() as u64) + } +} + +#[inline] +pub(crate) fn ioctl_fionbio(fd: BorrowedFd<'_>, value: bool) -> io::Result<()> { + unsafe { + let data = c::c_int::from(value); + ret(syscall_readonly!( + __NR_ioctl, + fd, + c_uint(FIONBIO), + by_ref(&data) + )) + } +} + +#[inline] +pub(crate) fn ioctl_tiocexcl(fd: BorrowedFd<'_>) -> io::Result<()> { + unsafe { ret(syscall_readonly!(__NR_ioctl, fd, c_uint(TIOCEXCL))) } +} + +#[inline] +pub(crate) fn ioctl_tiocnxcl(fd: BorrowedFd<'_>) -> io::Result<()> { + unsafe { ret(syscall_readonly!(__NR_ioctl, fd, c_uint(TIOCNXCL))) } +} + +#[inline] +pub(crate) fn ioctl_blksszget(fd: BorrowedFd) -> io::Result<u32> { + let mut result = MaybeUninit::<c::c_uint>::uninit(); + unsafe { + ret(syscall!(__NR_ioctl, fd, c_uint(BLKSSZGET), &mut result)) + .map(|()| result.assume_init() as u32) + } +} + +#[inline] +pub(crate) fn ioctl_blkpbszget(fd: BorrowedFd) -> io::Result<u32> { + let mut result = MaybeUninit::<c::c_uint>::uninit(); + unsafe { + ret(syscall!(__NR_ioctl, fd, c_uint(BLKPBSZGET), &mut result)) + .map(|()| result.assume_init() as u32) + } +} + +#[cfg(feature = "net")] +pub(crate) fn is_read_write(fd: BorrowedFd<'_>) -> io::Result<(bool, bool)> { + let (mut read, mut write) = crate::fs::fd::_is_file_read_write(fd)?; + let mut not_socket = false; + if read { + // Do a `recv` with `PEEK` and `DONTWAIT` for 1 byte. A 0 indicates + // the read side is shut down; an `EWOULDBLOCK` indicates the read + // side is still open. + // + // TODO: This code would benefit from having a better way to read into + // uninitialized memory. + let mut buf = [0]; + match super::super::net::syscalls::recv(fd, &mut buf, RecvFlags::PEEK | RecvFlags::DONTWAIT) + { + Ok(0) => read = false, + Err(err) => { + #[allow(unreachable_patterns)] // `EAGAIN` may equal `EWOULDBLOCK` + match err { + io::Errno::AGAIN | io::Errno::WOULDBLOCK => (), + io::Errno::NOTSOCK => not_socket = true, + _ => return Err(err), + } + } + Ok(_) => (), + } + } + if write && !not_socket { + // Do a `send` with `DONTWAIT` for 0 bytes. An `EPIPE` indicates + // the write side is shut down. + #[allow(unreachable_patterns)] // `EAGAIN` equals `EWOULDBLOCK` + match super::super::net::syscalls::send(fd, &[], SendFlags::DONTWAIT) { + // TODO or-patterns when we don't need 1.51 + Err(io::Errno::AGAIN) => (), + Err(io::Errno::WOULDBLOCK) => (), + Err(io::Errno::NOTSOCK) => (), + Err(io::Errno::PIPE) => write = false, + Err(err) => return Err(err), + Ok(_) => (), + } + } + Ok((read, write)) +} + +#[inline] +pub(crate) fn dup(fd: BorrowedFd<'_>) -> io::Result<OwnedFd> { + unsafe { ret_owned_fd(syscall_readonly!(__NR_dup, fd)) } +} + +#[inline] +pub(crate) fn dup2(fd: BorrowedFd<'_>, new: &mut OwnedFd) -> io::Result<()> { + #[cfg(any(target_arch = "aarch64", target_arch = "riscv64"))] + { + // We don't need to worry about the difference between `dup2` and + // `dup3` when the file descriptors are equal because we have an + // `&mut OwnedFd` which means `fd` doesn't alias it. + dup3(fd, new, DupFlags::empty()) + } + + #[cfg(not(any(target_arch = "aarch64", target_arch = "riscv64")))] + unsafe { + ret_discarded_fd(syscall_readonly!(__NR_dup2, fd, new.as_fd())) + } +} + +#[inline] +pub(crate) fn dup3(fd: BorrowedFd<'_>, new: &mut OwnedFd, flags: DupFlags) -> io::Result<()> { + unsafe { ret_discarded_fd(syscall_readonly!(__NR_dup3, fd, new.as_fd(), flags)) } +} + +#[inline] +pub(crate) fn pipe_with(flags: PipeFlags) -> io::Result<(OwnedFd, OwnedFd)> { + unsafe { + let mut result = MaybeUninit::<[OwnedFd; 2]>::uninit(); + ret(syscall!(__NR_pipe2, &mut result, flags))?; + let [p0, p1] = result.assume_init(); + Ok((p0, p1)) + } +} + +#[inline] +pub(crate) fn pipe() -> io::Result<(OwnedFd, OwnedFd)> { + // aarch64 and risc64 omit `__NR_pipe`. On mips, `__NR_pipe` uses a special + // calling convention, but using it is not worth complicating our syscall + // wrapping infrastructure at this time. + #[cfg(any( + target_arch = "aarch64", + target_arch = "mips", + target_arch = "mips64", + target_arch = "riscv64", + ))] + { + pipe_with(PipeFlags::empty()) + } + #[cfg(not(any( + target_arch = "aarch64", + target_arch = "mips", + target_arch = "mips64", + target_arch = "riscv64", + )))] + unsafe { + let mut result = MaybeUninit::<[OwnedFd; 2]>::uninit(); + ret(syscall!(__NR_pipe, &mut result))?; + let [p0, p1] = result.assume_init(); + Ok((p0, p1)) + } +} + +#[inline] +pub(crate) fn poll(fds: &mut [PollFd<'_>], timeout: c::c_int) -> io::Result<usize> { + let (fds_addr_mut, fds_len) = slice_mut(fds); + + #[cfg(any(target_arch = "aarch64", target_arch = "riscv64"))] + unsafe { + let timeout = if timeout >= 0 { + Some(__kernel_timespec { + tv_sec: (timeout as i64) / 1000, + tv_nsec: (timeout as i64) % 1000 * 1_000_000, + }) + } else { + None + }; + ret_usize(syscall!( + __NR_ppoll, + fds_addr_mut, + fds_len, + opt_ref(timeout.as_ref()), + zero(), + size_of::<sigset_t, _>() + )) + } + #[cfg(not(any(target_arch = "aarch64", target_arch = "riscv64")))] + unsafe { + ret_usize(syscall!(__NR_poll, fds_addr_mut, fds_len, c_int(timeout))) + } +} + +#[inline] +pub(crate) fn epoll_create(flags: epoll::CreateFlags) -> io::Result<OwnedFd> { + unsafe { ret_owned_fd(syscall_readonly!(__NR_epoll_create1, flags)) } +} + +#[inline] +pub(crate) unsafe fn epoll_add( + epfd: BorrowedFd<'_>, + fd: c::c_int, + event: &epoll_event, +) -> io::Result<()> { + ret(syscall_readonly!( + __NR_epoll_ctl, + epfd, + c_uint(EPOLL_CTL_ADD), + raw_fd(fd), + by_ref(event) + )) +} + +#[inline] +pub(crate) unsafe fn epoll_mod( + epfd: BorrowedFd<'_>, + fd: c::c_int, + event: &epoll_event, +) -> io::Result<()> { + ret(syscall_readonly!( + __NR_epoll_ctl, + epfd, + c_uint(EPOLL_CTL_MOD), + raw_fd(fd), + by_ref(event) + )) +} + +#[inline] +pub(crate) unsafe fn epoll_del(epfd: BorrowedFd<'_>, fd: c::c_int) -> io::Result<()> { + ret(syscall_readonly!( + __NR_epoll_ctl, + epfd, + c_uint(EPOLL_CTL_DEL), + raw_fd(fd), + zero() + )) +} + +#[inline] +pub(crate) fn epoll_wait( + epfd: BorrowedFd<'_>, + events: *mut epoll_event, + num_events: usize, + timeout: c::c_int, +) -> io::Result<usize> { + #[cfg(not(any(target_arch = "aarch64", target_arch = "riscv64")))] + unsafe { + ret_usize(syscall!( + __NR_epoll_wait, + epfd, + events, + pass_usize(num_events), + c_int(timeout) + )) + } + #[cfg(any(target_arch = "aarch64", target_arch = "riscv64"))] + unsafe { + ret_usize(syscall!( + __NR_epoll_pwait, + epfd, + events, + pass_usize(num_events), + c_int(timeout), + zero() + )) + } +} |