bjorn3
1058 lines
32 KiB
Rust
1058 lines
32 KiB
Rust
use core::{
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cell::SyncUnsafeCell,
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fmt::Debug,
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mem::{MaybeUninit, size_of},
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};
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use crate::{
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DYNAMIC_PROC_INFO, RtTcb, StaticProcInfo,
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arch::*,
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auxv_defs::*,
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protocol::{ProcCall, ThreadCall},
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read_proc_meta,
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sys::{proc_call, thread_call},
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};
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use alloc::{boxed::Box, collections::BTreeMap, vec};
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//TODO: allow use of either 32-bit or 64-bit programs
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#[cfg(target_pointer_width = "32")]
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use goblin::elf32::{
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header::Header,
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program_header::program_header32::{PF_R, PF_W, PF_X, PT_INTERP, PT_LOAD, ProgramHeader},
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};
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#[cfg(target_pointer_width = "64")]
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use goblin::elf64::{
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header::Header,
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program_header::program_header64::{PF_R, PF_W, PF_X, PT_INTERP, PT_LOAD, ProgramHeader},
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};
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use syscall::{
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CallFlags, GrantDesc, GrantFlags, MAP_FIXED_NOREPLACE, MAP_SHARED, Map, PAGE_SIZE, PROT_EXEC,
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PROT_READ, PROT_WRITE, SetSighandlerData,
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error::*,
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flag::{MapFlags, SEEK_SET},
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};
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pub enum FexecResult {
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Normal {
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addrspace_handle: FdGuardUpper,
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},
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Interp {
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path: Box<[u8]>,
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image_file: FdGuardUpper,
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interp_override: InterpOverride,
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},
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}
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pub struct InterpOverride {
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phs: Box<[u8]>,
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at_entry: usize,
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at_phnum: usize,
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at_phent: usize,
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name: Box<[u8]>,
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tree: BTreeMap<usize, usize>,
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}
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pub struct ExtraInfo<'a> {
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pub cwd: Option<&'a [u8]>,
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// Default scheme for the process
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pub default_scheme: Option<&'a [u8]>,
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// POSIX states that while sigactions are reset, ignored sigactions will remain ignored.
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pub sigignmask: u64,
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// POSIX also states that the sigprocmask must be preserved across execs.
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pub sigprocmask: u64,
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/// File mode creation mask (POSIX)
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pub umask: u32,
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/// Thread handle
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pub thr_fd: usize,
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/// Process handle
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pub proc_fd: usize,
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}
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pub fn fexec_impl(
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image_file: FdGuardUpper,
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thread_fd: &FdGuardUpper,
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proc_fd: &FdGuardUpper,
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memory_scheme_fd: &FdGuardUpper,
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path: &[u8],
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args: &[&[u8]],
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envs: &[&[u8]],
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extrainfo: &ExtraInfo,
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mut interp_override: Option<InterpOverride>,
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) -> Result<FexecResult> {
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// Here, we do the minimum part of loading an application, which is what the kernel used to do.
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// We load the executable into memory (albeit at different offsets in this executable), fix
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// some misalignments, and then switch address space.
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let mut header_bytes = [0_u8; size_of::<Header>()];
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pread_all(&image_file, 0, &mut header_bytes)?;
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let header = Header::from_bytes(&header_bytes);
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let grants_fd = {
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let current_addrspace_fd = thread_fd.dup(b"addrspace")?;
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current_addrspace_fd.dup(b"empty")?.to_upper()?
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};
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// Never allow more than 1 MiB of program headers.
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const MAX_PH_SIZE: usize = 1024 * 1024;
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let phentsize = u64::from(header.e_phentsize) as usize;
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let phnum = u64::from(header.e_phnum) as usize;
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let pheaders_size = phentsize
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.saturating_mul(phnum)
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.saturating_add(size_of::<Header>());
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if pheaders_size > MAX_PH_SIZE {
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return Err(Error::new(E2BIG));
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}
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let mut phs_raw = vec![0_u8; pheaders_size];
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phs_raw[..size_of::<Header>()].copy_from_slice(&header_bytes);
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let phs = &mut phs_raw[size_of::<Header>()..];
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// TODO: Remove clone, but this would require more as_refs and as_muts
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let mut tree = interp_override.as_mut().map_or_else(
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|| core::iter::once((0, PAGE_SIZE)).collect::<BTreeMap<_, _>>(),
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|o| core::mem::take(&mut o.tree),
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);
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pread_all(&image_file, u64::from(header.e_phoff), phs).map_err(|_| Error::new(EIO))?;
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for ph_idx in 0..phnum {
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let ph_bytes = &phs[ph_idx * phentsize..(ph_idx + 1) * phentsize];
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let segment: &ProgramHeader =
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plain::from_bytes(ph_bytes).map_err(|_| Error::new(EINVAL))?;
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let mut flags = if segment.p_flags & PF_R == PF_R {
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syscall::PROT_READ
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} else {
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syscall::PROT_NONE
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};
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// W ^ X. If it is executable, do not allow it to be writable, even if requested
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if segment.p_flags & PF_X == PF_X {
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flags |= syscall::PROT_EXEC;
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} else if segment.p_flags & PF_W == PF_W {
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flags |= syscall::PROT_WRITE;
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}
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match segment.p_type {
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// PT_INTERP must come before any PT_LOAD, so we don't have to iterate twice.
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PT_INTERP => {
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let mut interp = vec![0_u8; segment.p_filesz as usize];
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pread_all(&image_file, u64::from(segment.p_offset), &mut interp)?;
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return Ok(FexecResult::Interp {
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path: interp.into_boxed_slice(),
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image_file,
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interp_override: InterpOverride {
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at_entry: header.e_entry as usize,
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at_phnum: phnum,
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at_phent: phentsize,
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phs: phs_raw.into_boxed_slice(),
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name: path.into(),
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tree,
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},
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});
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}
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PT_LOAD => {
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let voff = segment.p_vaddr as usize % PAGE_SIZE;
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let vaddr = segment.p_vaddr as usize - voff;
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let filesz = segment.p_filesz as usize;
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let total_page_count = (segment.p_memsz as usize + voff).div_ceil(PAGE_SIZE);
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// The case where segments overlap so that they share one page, is not handled.
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// TODO: Should it be?
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if segment.p_filesz > segment.p_memsz {
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return Err(Error::new(ENOEXEC));
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}
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allocate_remote(
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&grants_fd,
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memory_scheme_fd,
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vaddr,
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total_page_count * PAGE_SIZE,
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flags,
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)?;
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// TODO: Attempt to mmap with MAP_PRIVATE directly from the image file instead.
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if filesz > 0 {
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let (_guard, dst_memory) = unsafe {
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MmapGuard::map_mut_anywhere(
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&grants_fd,
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vaddr, // offset
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(voff + filesz).next_multiple_of(PAGE_SIZE), // size
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)?
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};
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pread_all(
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&image_file,
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u64::from(segment.p_offset),
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&mut dst_memory[voff..voff + filesz],
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)?;
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}
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// file_page_count..file_page_count + zero_page_count are already zero-initialized
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// by the kernel.
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if !tree
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.range(..=vaddr)
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.next_back()
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.filter(|(start, size)| **start + **size > vaddr)
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.is_some()
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{
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tree.insert(vaddr, total_page_count * PAGE_SIZE);
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}
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}
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_ => continue,
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}
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}
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allocate_remote(
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&grants_fd,
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memory_scheme_fd,
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STACK_TOP - STACK_SIZE,
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STACK_SIZE,
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MapFlags::PROT_READ | MapFlags::PROT_WRITE,
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)?;
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tree.insert(STACK_TOP - STACK_SIZE, STACK_SIZE);
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let mut sp = STACK_TOP;
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let mut stack_page = Option::<MmapGuard>::None;
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let mut push = |word: usize| {
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let old_page_no = sp / PAGE_SIZE;
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sp -= size_of::<usize>();
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let new_page_no = sp / PAGE_SIZE;
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let new_page_off = sp % PAGE_SIZE;
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let page = if let Some(ref mut page) = stack_page
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&& old_page_no == new_page_no
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{
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page
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} else if let Some(ref mut stack_page) = stack_page {
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stack_page.remap(new_page_no * PAGE_SIZE, PROT_READ | PROT_WRITE)?;
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stack_page
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} else {
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let new = MmapGuard::map(
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&grants_fd,
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&Map {
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offset: new_page_no * PAGE_SIZE,
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size: PAGE_SIZE,
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flags: PROT_READ | PROT_WRITE,
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address: 0, // let kernel decide
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},
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)?;
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stack_page.insert(new)
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};
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unsafe {
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page.as_mut_ptr_slice()
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.as_mut_ptr()
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.add(new_page_off)
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.cast::<usize>()
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.write(word);
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}
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Ok(())
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};
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let pheaders_to_convey = if let Some(ref r#override) = interp_override {
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&*r#override.phs
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} else {
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&*phs_raw
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};
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let pheaders_size_aligned = pheaders_to_convey.len().next_multiple_of(PAGE_SIZE);
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let pheaders = find_free_target_addr(&tree, pheaders_size_aligned).ok_or(Error::new(ENOMEM))?;
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tree.insert(pheaders, pheaders_size_aligned);
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allocate_remote(
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&grants_fd,
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memory_scheme_fd,
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pheaders,
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pheaders_size_aligned,
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MapFlags::PROT_READ | MapFlags::PROT_WRITE,
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)?;
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unsafe {
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let (_guard, memory) =
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MmapGuard::map_mut_anywhere(&grants_fd, pheaders, pheaders_size_aligned)?;
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memory[..pheaders_to_convey.len()].copy_from_slice(pheaders_to_convey);
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}
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mprotect_remote(
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&grants_fd,
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pheaders,
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pheaders_size_aligned,
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MapFlags::PROT_READ,
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)?;
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push(0)?;
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push(AT_NULL)?;
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push(header.e_entry as usize)?;
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if let Some(ref r#override) = interp_override {
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push(AT_BASE)?;
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push(r#override.at_entry)?;
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}
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push(AT_ENTRY)?;
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push(pheaders + size_of::<Header>())?;
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push(AT_PHDR)?;
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push(
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interp_override
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.as_ref()
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.map_or(header.e_phnum as usize, |o| o.at_phnum),
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)?;
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push(AT_PHNUM)?;
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push(
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interp_override
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.as_ref()
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.map_or(header.e_phentsize as usize, |o| o.at_phent),
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)?;
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push(AT_PHENT)?;
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let total_args_envs_auxvpointee_size = args.iter().map(|arg| arg.len() + 1).sum::<usize>()
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+ envs.iter().map(|env| env.len() + 1).sum::<usize>()
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+ extrainfo.cwd.map_or(0, |s| s.len() + 1)
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+ extrainfo.default_scheme.map_or(0, |s| s.len() + 1);
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let args_envs_size_aligned = total_args_envs_auxvpointee_size.next_multiple_of(PAGE_SIZE);
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let target_args_env_address =
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find_free_target_addr(&tree, args_envs_size_aligned).ok_or(Error::new(ENOMEM))?;
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allocate_remote(
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&grants_fd,
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memory_scheme_fd,
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target_args_env_address,
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args_envs_size_aligned,
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MapFlags::PROT_READ | MapFlags::PROT_WRITE,
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)?;
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tree.insert(target_args_env_address, args_envs_size_aligned);
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let mut offset = 0;
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let mut argc = 0;
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{
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let mut append = |source_slice: &[u8]| {
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// TODO
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let address = target_args_env_address + offset;
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if !source_slice.is_empty() {
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let containing_page = address.div_floor(PAGE_SIZE) * PAGE_SIZE;
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let displacement = address - containing_page;
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let size = source_slice.len() + displacement;
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let aligned_size = size.next_multiple_of(PAGE_SIZE);
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let (_guard, memory) = unsafe {
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MmapGuard::map_mut_anywhere(&grants_fd, containing_page, aligned_size)?
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};
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memory[displacement..][..source_slice.len()].copy_from_slice(source_slice);
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}
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offset += source_slice.len() + 1;
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Ok(address)
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};
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if let Some(cwd) = extrainfo.cwd {
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push(append(cwd)?)?;
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push(AT_REDOX_INITIAL_CWD_PTR)?;
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push(cwd.len())?;
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push(AT_REDOX_INITIAL_CWD_LEN)?;
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}
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if let Some(default_scheme) = extrainfo.default_scheme {
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push(append(default_scheme)?)?;
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push(AT_REDOX_INITIAL_DEFAULT_SCHEME_PTR)?;
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push(default_scheme.len())?;
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push(AT_REDOX_INITIAL_DEFAULT_SCHEME_LEN)?;
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}
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|
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#[cfg(target_pointer_width = "32")]
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{
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push((extrainfo.sigignmask >> 32) as usize)?;
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push(AT_REDOX_INHERITED_SIGIGNMASK_HI)?;
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}
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push(extrainfo.sigignmask as usize)?;
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push(AT_REDOX_INHERITED_SIGIGNMASK)?;
|
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#[cfg(target_pointer_width = "32")]
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{
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push((extrainfo.sigprocmask >> 32) as usize)?;
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push(AT_REDOX_INHERITED_SIGPROCMASK_HI)?;
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}
|
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push(extrainfo.sigprocmask as usize)?;
|
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push(AT_REDOX_INHERITED_SIGPROCMASK)?;
|
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|
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push(extrainfo.umask as usize)?;
|
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push(AT_REDOX_UMASK)?;
|
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|
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push(extrainfo.thr_fd as usize)?;
|
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push(AT_REDOX_THR_FD)?;
|
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push(extrainfo.proc_fd as usize)?;
|
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push(AT_REDOX_PROC_FD)?;
|
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|
|
push(0)?;
|
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|
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for env in envs.iter().rev() {
|
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push(append(env)?)?;
|
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}
|
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|
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push(0)?;
|
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|
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for arg in args.iter().rev() {
|
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push(append(arg)?)?;
|
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argc += 1;
|
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}
|
|
}
|
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|
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push(argc)?;
|
|
|
|
if let Ok(sighandler_fd) = thread_fd.dup(b"sighandler") {
|
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let _ = sighandler_fd.write(&SetSighandlerData {
|
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user_handler: 0,
|
|
excp_handler: 0,
|
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thread_control_addr: 0,
|
|
proc_control_addr: 0,
|
|
});
|
|
// TODO: sync with procmgr
|
|
}
|
|
|
|
unsafe {
|
|
deactivate_tcb(&thread_fd)?;
|
|
}
|
|
|
|
// TODO: Restore old name if exec failed?
|
|
{
|
|
let mut buf = [0; 32];
|
|
let new_name = interp_override.as_ref().map_or(path, |o| &o.name);
|
|
let len = new_name.len().min(32);
|
|
buf[..len].copy_from_slice(&new_name[..len]);
|
|
// XXX: takes &mut [] since it can mutate, but we could unsafe{}ly pass it directly
|
|
// otherwise
|
|
let _ = proc_call(
|
|
proc_fd.as_raw_fd(),
|
|
&mut buf,
|
|
CallFlags::empty(),
|
|
&[ProcCall::Rename as u64],
|
|
);
|
|
}
|
|
|
|
// TODO: Error handling
|
|
let _ = proc_call(
|
|
proc_fd.as_raw_fd(),
|
|
&mut [],
|
|
CallFlags::empty(),
|
|
&[ProcCall::DisableSetpgid as u64],
|
|
);
|
|
|
|
if interp_override.is_some() {
|
|
let mmap_min_fd = grants_fd.dup(b"mmap-min-addr")?;
|
|
let last_addr = tree.iter().rev().nth(1).map_or(0, |(off, len)| *off + *len);
|
|
let aligned_last_addr = last_addr.next_multiple_of(PAGE_SIZE);
|
|
let _ = mmap_min_fd.write(&usize::to_ne_bytes(aligned_last_addr));
|
|
}
|
|
|
|
let addrspace_selection_fd = thread_fd.dup(b"current-addrspace")?.to_upper()?;
|
|
|
|
let _ = addrspace_selection_fd.write(&create_set_addr_space_buf(
|
|
grants_fd.as_raw_fd(),
|
|
header.e_entry as usize,
|
|
sp,
|
|
));
|
|
|
|
Ok(FexecResult::Normal {
|
|
addrspace_handle: addrspace_selection_fd,
|
|
})
|
|
}
|
|
fn write_usizes<const N: usize>(fd: &FdGuardUpper, usizes: [usize; N]) -> Result<()> {
|
|
fd.write(unsafe { plain::as_bytes(&usizes) })?;
|
|
Ok(())
|
|
}
|
|
fn allocate_remote(
|
|
addrspace_fd: &FdGuardUpper,
|
|
memory_scheme_fd: &FdGuardUpper,
|
|
dst_addr: usize,
|
|
len: usize,
|
|
flags: MapFlags,
|
|
) -> Result<()> {
|
|
mmap_remote(addrspace_fd, memory_scheme_fd, 0, dst_addr, len, flags)
|
|
}
|
|
pub fn mmap_remote(
|
|
addrspace_fd: &FdGuardUpper,
|
|
fd: &FdGuardUpper,
|
|
offset: usize,
|
|
dst_addr: usize,
|
|
len: usize,
|
|
flags: MapFlags,
|
|
) -> Result<()> {
|
|
write_usizes(
|
|
addrspace_fd,
|
|
[
|
|
// op
|
|
syscall::flag::ADDRSPACE_OP_MMAP,
|
|
// fd
|
|
fd.as_raw_fd(),
|
|
// "offset"
|
|
offset,
|
|
// address
|
|
dst_addr,
|
|
// size
|
|
len,
|
|
// flags
|
|
(flags | MapFlags::MAP_FIXED_NOREPLACE).bits(),
|
|
],
|
|
)
|
|
}
|
|
pub fn mprotect_remote(
|
|
addrspace_fd: &FdGuardUpper,
|
|
addr: usize,
|
|
len: usize,
|
|
flags: MapFlags,
|
|
) -> Result<()> {
|
|
write_usizes(
|
|
addrspace_fd,
|
|
[
|
|
// op
|
|
syscall::flag::ADDRSPACE_OP_MPROTECT,
|
|
// address
|
|
addr,
|
|
// size
|
|
len,
|
|
// flags
|
|
flags.bits(),
|
|
],
|
|
)
|
|
}
|
|
pub fn munmap_remote(addrspace_fd: &FdGuardUpper, addr: usize, len: usize) -> Result<()> {
|
|
write_usizes(
|
|
addrspace_fd,
|
|
[
|
|
// op
|
|
syscall::flag::ADDRSPACE_OP_MUNMAP,
|
|
// address
|
|
addr,
|
|
// size
|
|
len,
|
|
],
|
|
)
|
|
}
|
|
pub fn munmap_transfer(
|
|
src: &FdGuardUpper,
|
|
dst: &FdGuardUpper,
|
|
src_addr: usize,
|
|
dst_addr: usize,
|
|
len: usize,
|
|
flags: MapFlags,
|
|
) -> Result<()> {
|
|
write_usizes(
|
|
dst,
|
|
[
|
|
// op
|
|
syscall::flag::ADDRSPACE_OP_TRANSFER,
|
|
// fd
|
|
src.as_raw_fd(),
|
|
// "offset" (source address)
|
|
src_addr,
|
|
// address
|
|
dst_addr,
|
|
// size
|
|
len,
|
|
// flags
|
|
(flags | MapFlags::MAP_FIXED_NOREPLACE).bits(),
|
|
],
|
|
)
|
|
}
|
|
fn pread_all(fd: &FdGuardUpper, offset: u64, buf: &mut [u8]) -> Result<()> {
|
|
fd.lseek(offset as isize, SEEK_SET)?;
|
|
|
|
let mut total_bytes_read = 0;
|
|
|
|
while total_bytes_read < buf.len() {
|
|
total_bytes_read += match fd.read(&mut buf[total_bytes_read..])? {
|
|
0 => return Err(Error::new(ENOEXEC)),
|
|
bytes_read => bytes_read,
|
|
}
|
|
}
|
|
Ok(())
|
|
}
|
|
|
|
// TODO: With the introduction of remote mmaps, remove this and let the kernel handle address
|
|
// allocation.
|
|
fn find_free_target_addr(tree: &BTreeMap<usize, usize>, size: usize) -> Option<usize> {
|
|
let mut iterator = tree.iter().peekable();
|
|
|
|
// Ignore the space between zero and the first region, to avoid null pointers.
|
|
while let Some((cur_address, entry_size)) = iterator.next() {
|
|
let end = *cur_address + entry_size;
|
|
|
|
if let Some((next_address, _)) = iterator.peek() {
|
|
if **next_address - end > size {
|
|
return Some(end);
|
|
}
|
|
}
|
|
// No need to check last entry, since the stack will always be put at the highest
|
|
// possible address.
|
|
}
|
|
|
|
None
|
|
}
|
|
|
|
pub struct MmapGuard<'a> {
|
|
fd: &'a FdGuardUpper,
|
|
base: usize,
|
|
size: usize,
|
|
}
|
|
impl<'a> MmapGuard<'a> {
|
|
pub fn map(fd: &'a FdGuardUpper, map: &Map) -> Result<Self> {
|
|
let base = unsafe { syscall::fmap(fd.as_raw_fd(), map)? };
|
|
Ok(Self {
|
|
fd,
|
|
size: map.size,
|
|
base,
|
|
})
|
|
}
|
|
pub fn remap(&mut self, offset: usize, mut flags: MapFlags) -> Result<()> {
|
|
flags.remove(MapFlags::MAP_FIXED_NOREPLACE);
|
|
flags.insert(MapFlags::MAP_FIXED);
|
|
|
|
let _new_base = unsafe {
|
|
syscall::fmap(
|
|
self.fd.as_raw_fd(),
|
|
&Map {
|
|
offset,
|
|
size: self.size,
|
|
flags,
|
|
address: self.base,
|
|
},
|
|
)?
|
|
};
|
|
|
|
Ok(())
|
|
}
|
|
pub unsafe fn map_mut_anywhere(
|
|
fd: &'a FdGuardUpper,
|
|
offset: usize,
|
|
size: usize,
|
|
) -> Result<(Self, &'a mut [u8])> {
|
|
let mut this = Self::map(
|
|
fd,
|
|
&Map {
|
|
size,
|
|
offset,
|
|
address: 0,
|
|
flags: PROT_READ | PROT_WRITE,
|
|
},
|
|
)?;
|
|
let slice = unsafe { &mut *this.as_mut_ptr_slice() };
|
|
|
|
Ok((this, slice))
|
|
}
|
|
pub fn addr(&self) -> usize {
|
|
self.base
|
|
}
|
|
pub fn len(&self) -> usize {
|
|
self.size
|
|
}
|
|
pub fn as_mut_ptr_slice(&mut self) -> *mut [u8] {
|
|
core::ptr::slice_from_raw_parts_mut(self.base as *mut u8, self.size)
|
|
}
|
|
pub fn take(mut self) {
|
|
self.size = 0;
|
|
}
|
|
}
|
|
impl<'a> Drop for MmapGuard<'a> {
|
|
fn drop(&mut self) {
|
|
if self.size != 0 {
|
|
let _ = unsafe { syscall::funmap(self.base, self.size) };
|
|
}
|
|
}
|
|
}
|
|
|
|
#[repr(transparent)]
|
|
pub struct FdGuard<const UPPER: bool = false> {
|
|
fd: usize,
|
|
}
|
|
pub type FdGuardUpper = FdGuard<true>;
|
|
impl FdGuard<false> {
|
|
#[inline]
|
|
pub fn new(fd: usize) -> Self {
|
|
Self { fd }
|
|
}
|
|
|
|
#[inline]
|
|
pub fn open<T: AsRef<str>>(path: T, flags: usize) -> Result<Self> {
|
|
syscall::open(path, flags).map(Self::new)
|
|
}
|
|
|
|
#[inline]
|
|
pub fn to_upper(self) -> Result<FdGuardUpper> {
|
|
// Move to upper table if necessary
|
|
let fd = if self.fd & syscall::UPPER_FDTBL_TAG == 0 {
|
|
//TODO: use F_DUPFD_CLOEXEC?
|
|
let fd = syscall::fcntl(self.fd, syscall::F_DUPFD, syscall::UPPER_FDTBL_TAG)?;
|
|
drop(self);
|
|
fd
|
|
} else {
|
|
self.take()
|
|
};
|
|
Ok(FdGuard::<true> { fd })
|
|
}
|
|
|
|
// Not implemented for UPPER to prevent misuse
|
|
#[inline]
|
|
pub fn as_c_fd(&self) -> Option<i32> {
|
|
i32::try_from(self.fd).ok()
|
|
}
|
|
}
|
|
impl<const UPPER: bool> FdGuard<UPPER> {
|
|
#[inline]
|
|
pub fn dup(&self, buf: &[u8]) -> Result<FdGuard<false>> {
|
|
syscall::dup(self.fd, buf).map(FdGuard::new)
|
|
}
|
|
|
|
#[inline]
|
|
pub fn fcntl(&self, cmd: usize, arg: usize) -> Result<usize> {
|
|
syscall::fcntl(self.fd, cmd, arg)
|
|
}
|
|
|
|
#[inline]
|
|
pub fn fstat(&self, stat: &mut syscall::Stat) -> Result<usize> {
|
|
syscall::fstat(self.fd, stat)
|
|
}
|
|
|
|
#[inline]
|
|
pub fn lseek(&self, offset: isize, whence: usize) -> Result<usize> {
|
|
syscall::lseek(self.fd, offset, whence)
|
|
}
|
|
|
|
#[inline]
|
|
pub fn read(&self, buf: &mut [u8]) -> Result<usize> {
|
|
syscall::read(self.fd, buf)
|
|
}
|
|
|
|
#[inline]
|
|
pub fn write(&self, buf: &[u8]) -> Result<usize> {
|
|
syscall::write(self.fd, buf)
|
|
}
|
|
|
|
#[inline]
|
|
pub fn as_raw_fd(&self) -> usize {
|
|
self.fd
|
|
}
|
|
|
|
#[inline]
|
|
pub fn take(self) -> usize {
|
|
let fd = self.fd;
|
|
core::mem::forget(self);
|
|
fd
|
|
}
|
|
}
|
|
impl<const UPPER: bool> Drop for FdGuard<UPPER> {
|
|
#[inline]
|
|
fn drop(&mut self) {
|
|
let _ = syscall::close(self.fd);
|
|
}
|
|
}
|
|
impl Debug for FdGuard<false> {
|
|
fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
|
|
write!(f, "[fd {}]", self.fd)
|
|
}
|
|
}
|
|
impl Debug for FdGuardUpper {
|
|
fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
|
|
write!(f, "[fd upper {}]", self.fd & !syscall::UPPER_FDTBL_TAG)
|
|
}
|
|
}
|
|
pub fn create_set_addr_space_buf(
|
|
space: usize,
|
|
ip: usize,
|
|
sp: usize,
|
|
) -> [u8; size_of::<usize>() * 3] {
|
|
let mut buf = [0u8; size_of::<usize>() * 3];
|
|
|
|
buf.copy_from_slice([space, sp, ip].map(usize::to_ne_bytes).as_flattened());
|
|
|
|
buf
|
|
}
|
|
|
|
/// Spawns a new context which will not share the same address space as the current one. File
|
|
/// descriptors from other schemes are reobtained with `dup`, and grants referencing such file
|
|
/// descriptors are reobtained through `fmap`. Other mappings are kept but duplicated using CoW.
|
|
pub fn fork_impl(args: &ForkArgs<'_>) -> Result<usize> {
|
|
let old_mask = crate::signal::get_sigmask()?;
|
|
let pid = unsafe {
|
|
Error::demux(__relibc_internal_fork_wrapper(
|
|
args as *const ForkArgs as usize,
|
|
))?
|
|
};
|
|
|
|
if pid == 0 {
|
|
crate::signal::set_sigmask(Some(old_mask), None)?;
|
|
}
|
|
Ok(pid)
|
|
}
|
|
|
|
pub enum ForkArgs<'a> {
|
|
Init {
|
|
this_thr_fd: &'a FdGuardUpper,
|
|
auth: &'a FdGuard,
|
|
},
|
|
Managed,
|
|
}
|
|
|
|
pub fn fork_inner(initial_rsp: *mut usize, args: &ForkArgs) -> Result<usize> {
|
|
let (cur_filetable_fd, new_proc_fd, new_thr_fd, new_pid);
|
|
|
|
{
|
|
let cur_thr_fd = match args {
|
|
ForkArgs::Init { this_thr_fd, .. } => this_thr_fd,
|
|
ForkArgs::Managed => RtTcb::current().thread_fd(),
|
|
};
|
|
let NewChildProc {
|
|
proc_fd,
|
|
thr_fd,
|
|
pid,
|
|
} = new_child_process(args)?;
|
|
new_proc_fd = proc_fd;
|
|
new_thr_fd = thr_fd;
|
|
new_pid = pid;
|
|
|
|
// Copy existing files into new file table, but do not reuse the same file table (i.e. new
|
|
// parent FDs will not show up for the child).
|
|
{
|
|
cur_filetable_fd = cur_thr_fd.dup(b"filetable")?;
|
|
|
|
// This must be done before the address space is copied.
|
|
unsafe {
|
|
let proc_fd = new_proc_fd.as_ref().map_or(usize::MAX, |p| p.as_raw_fd());
|
|
//let _ = syscall::write(1, alloc::format!("FDTBL{}PROC{}THR{}\n", *cur_filetable_fd, proc_fd, *new_thr_fd).as_bytes());
|
|
initial_rsp.write(cur_filetable_fd.as_raw_fd());
|
|
initial_rsp.add(1).write(proc_fd);
|
|
initial_rsp.add(2).write(new_thr_fd.as_raw_fd());
|
|
}
|
|
}
|
|
|
|
// CoW-duplicate address space.
|
|
{
|
|
let new_addr_space_sel_fd = new_thr_fd.dup(b"current-addrspace")?;
|
|
|
|
let cur_addr_space_fd = cur_thr_fd.dup(b"addrspace")?.to_upper()?;
|
|
let new_addr_space_fd = cur_addr_space_fd.dup(b"exclusive")?.to_upper()?;
|
|
|
|
let mut grant_desc_buf = [GrantDesc::default(); 16];
|
|
loop {
|
|
let bytes_read = {
|
|
let buf = unsafe {
|
|
core::slice::from_raw_parts_mut(
|
|
grant_desc_buf.as_mut_ptr().cast(),
|
|
grant_desc_buf.len() * size_of::<GrantDesc>(),
|
|
)
|
|
};
|
|
cur_addr_space_fd.read(buf)?
|
|
};
|
|
if bytes_read == 0 {
|
|
break;
|
|
}
|
|
|
|
let grants = &grant_desc_buf[..bytes_read / size_of::<GrantDesc>()];
|
|
|
|
for grant in grants {
|
|
if !grant.flags.contains(GrantFlags::GRANT_SCHEME)
|
|
|| !grant.flags.contains(GrantFlags::GRANT_SHARED)
|
|
{
|
|
continue;
|
|
}
|
|
|
|
let buf;
|
|
|
|
// TODO: write! using some #![no_std] Cursor type (tracking the length)?
|
|
#[cfg(target_pointer_width = "64")]
|
|
{
|
|
//buf = *b"grant-fd-AAAABBBBCCCCDDDD";
|
|
//write!(&mut buf, "grant-fd-{:>016x}", grant.base).unwrap();
|
|
buf = alloc::format!("grant-fd-{:>016x}", grant.base).into_bytes();
|
|
}
|
|
|
|
#[cfg(target_pointer_width = "32")]
|
|
{
|
|
//buf = *b"grant-fd-AAAABBBB";
|
|
//write!(&mut buf[..], "grant-fd-{:>08x}", grant.base).unwrap();
|
|
buf = alloc::format!("grant-fd-{:>08x}", grant.base).into_bytes();
|
|
}
|
|
|
|
let grant_fd = cur_addr_space_fd.dup(&buf)?.to_upper()?;
|
|
|
|
let mut flags = MAP_SHARED | MAP_FIXED_NOREPLACE;
|
|
|
|
flags.set(PROT_READ, grant.flags.contains(GrantFlags::GRANT_READ));
|
|
flags.set(PROT_WRITE, grant.flags.contains(GrantFlags::GRANT_WRITE));
|
|
flags.set(PROT_EXEC, grant.flags.contains(GrantFlags::GRANT_EXEC));
|
|
|
|
mmap_remote(
|
|
&new_addr_space_fd,
|
|
&grant_fd,
|
|
grant.offset as usize,
|
|
grant.base,
|
|
grant.size,
|
|
flags,
|
|
)?;
|
|
}
|
|
}
|
|
|
|
let buf = create_set_addr_space_buf(
|
|
new_addr_space_fd.as_raw_fd(),
|
|
__relibc_internal_fork_ret as usize,
|
|
initial_rsp as usize,
|
|
);
|
|
new_addr_space_sel_fd.write(&buf)?;
|
|
}
|
|
{
|
|
// Reuse the same sigaltstack and signal entry (all memory will be re-mapped CoW later).
|
|
//
|
|
// Do this after the address space is cloned, since the kernel will get a shared
|
|
// reference to the TCB and whatever pages stores the signal proc control struct.
|
|
{
|
|
let new_sighandler_fd = new_thr_fd.dup(b"sighandler")?;
|
|
new_sighandler_fd.write(&crate::signal::current_setsighandler_struct())?;
|
|
}
|
|
if let Some(ref proc_fd) = new_proc_fd {
|
|
proc_call(
|
|
proc_fd.as_raw_fd(),
|
|
&mut [],
|
|
CallFlags::empty(),
|
|
&[ProcCall::SyncSigPctl as u64],
|
|
)?;
|
|
thread_call(
|
|
new_thr_fd.as_raw_fd(),
|
|
&mut [],
|
|
CallFlags::empty(),
|
|
&[ThreadCall::SyncSigTctl as u64],
|
|
)?;
|
|
}
|
|
}
|
|
{
|
|
// Copy environment registers.
|
|
let cur_env_regs_fd = cur_thr_fd.dup(b"regs/env")?;
|
|
let new_env_regs_fd = new_thr_fd.dup(b"regs/env")?;
|
|
|
|
let mut env_regs = syscall::EnvRegisters::default();
|
|
cur_env_regs_fd.read(&mut env_regs)?;
|
|
new_env_regs_fd.write(&env_regs)?;
|
|
}
|
|
}
|
|
// Copy the file table. We do this last to ensure that all previously used file descriptors are
|
|
// closed. The only exception -- the filetable selection fd and the current filetable fd --
|
|
// will be closed by the child process.
|
|
{
|
|
// TODO: Use file descriptor forwarding or something similar to avoid copying the file
|
|
// table in the kernel.
|
|
let new_filetable_fd = cur_filetable_fd.dup(b"copy")?;
|
|
let new_filetable_sel_fd = new_thr_fd.dup(b"current-filetable")?;
|
|
new_filetable_sel_fd.write(&usize::to_ne_bytes(new_filetable_fd.as_raw_fd()))?;
|
|
}
|
|
let start_fd = new_thr_fd.dup(b"start")?;
|
|
start_fd.write(&[0])?;
|
|
|
|
Ok(new_pid)
|
|
}
|
|
|
|
pub struct NewChildProc {
|
|
proc_fd: Option<FdGuardUpper>,
|
|
|
|
thr_fd: FdGuardUpper,
|
|
pid: usize,
|
|
}
|
|
|
|
pub fn new_child_process(args: &ForkArgs<'_>) -> Result<NewChildProc> {
|
|
match *args {
|
|
ForkArgs::Managed => {
|
|
let proc_info = crate::static_proc_info();
|
|
assert!(
|
|
proc_info.has_proc_fd,
|
|
"cannot use ForkArgs::Managed without an existing proc info"
|
|
);
|
|
let this_proc_fd = unsafe { proc_info.proc_fd.assume_init_ref() };
|
|
let child_proc_fd = this_proc_fd.dup(b"fork")?.to_upper()?;
|
|
let only_thread_fd = child_proc_fd.dup(b"thread-0")?.to_upper()?;
|
|
let meta = read_proc_meta(&child_proc_fd)?;
|
|
Ok(NewChildProc {
|
|
proc_fd: Some(child_proc_fd),
|
|
thr_fd: only_thread_fd,
|
|
pid: meta.pid as usize,
|
|
})
|
|
}
|
|
#[cfg(feature = "proc")]
|
|
ForkArgs::Init { .. } => unreachable!(),
|
|
|
|
#[cfg(not(feature = "proc"))]
|
|
ForkArgs::Init { this_thr_fd, auth } => {
|
|
let thr_fd = auth.dup(b"new-context")?.to_upper()?;
|
|
let buf = syscall::ProcSchemeAttrs {
|
|
pid: 0,
|
|
euid: 0,
|
|
egid: 0,
|
|
ens: 1,
|
|
debug_name: {
|
|
let mut buf = [0; 32];
|
|
let src = b"[init]";
|
|
buf[..src.len()].copy_from_slice(src);
|
|
buf
|
|
},
|
|
};
|
|
let attr_fd =
|
|
thr_fd.dup(alloc::format!("auth-{}-attrs", auth.as_raw_fd()).as_bytes())?;
|
|
attr_fd.write(&buf)?;
|
|
Ok(NewChildProc {
|
|
thr_fd,
|
|
pid: 1, // dummy fd to distinguish child from parent
|
|
proc_fd: None,
|
|
})
|
|
}
|
|
}
|
|
}
|
|
|
|
pub unsafe fn make_init() -> (&'static FdGuardUpper, &'static FdGuardUpper) {
|
|
let proc_fd = FdGuard::new(
|
|
syscall::open("/scheme/proc/init", syscall::O_CLOEXEC).expect("failed to create init"),
|
|
)
|
|
.to_upper()
|
|
.unwrap();
|
|
syscall::sendfd(
|
|
proc_fd.as_raw_fd(),
|
|
RtTcb::current().thread_fd().dup(&[]).unwrap().take(),
|
|
0,
|
|
0,
|
|
)
|
|
.expect("failed to assign current thread to init process");
|
|
|
|
let managed_thr_fd = proc_fd
|
|
.dup(b"thread-0")
|
|
.expect("failed to get managed thread for init")
|
|
.to_upper()
|
|
.unwrap();
|
|
|
|
let managed_thr_fd = unsafe { (*RtTcb::current().thr_fd.get()).insert(managed_thr_fd) };
|
|
|
|
unsafe {
|
|
STATIC_PROC_INFO.get().write(crate::StaticProcInfo {
|
|
pid: 1,
|
|
proc_fd: MaybeUninit::new(proc_fd),
|
|
has_proc_fd: true,
|
|
})
|
|
};
|
|
*DYNAMIC_PROC_INFO.lock() = crate::DynamicProcInfo {
|
|
pgid: 1,
|
|
ruid: 0,
|
|
euid: 0,
|
|
suid: 0,
|
|
rgid: 0,
|
|
egid: 0,
|
|
sgid: 0,
|
|
};
|
|
(
|
|
unsafe { (*STATIC_PROC_INFO.get()).proc_fd.assume_init_ref() },
|
|
managed_thr_fd,
|
|
)
|
|
}
|
|
pub(crate) static STATIC_PROC_INFO: SyncUnsafeCell<StaticProcInfo> =
|
|
SyncUnsafeCell::new(StaticProcInfo {
|
|
pid: 0,
|
|
proc_fd: MaybeUninit::zeroed(),
|
|
has_proc_fd: false,
|
|
});
|