111 lines
3.6 KiB
Rust
111 lines
3.6 KiB
Rust
pub mod elf;
|
|
mod shebang;
|
|
|
|
use crate::fs::fs_resolver::{FsPath, FsResolver, AT_FDCWD};
|
|
use crate::fs::utils::Dentry;
|
|
use crate::prelude::*;
|
|
use crate::vdso::vdso_vmo;
|
|
use crate::vm::perms::VmPerms;
|
|
|
|
use self::elf::{load_elf_to_vm, ElfLoadInfo};
|
|
use self::shebang::parse_shebang_line;
|
|
|
|
use super::process_vm::ProcessVm;
|
|
|
|
/// Map the vdso vmo to the corresponding virtual memory address.
|
|
pub fn map_vdso_to_vm(process_vm: &ProcessVm) -> Vaddr {
|
|
let root_vmar = process_vm.root_vmar();
|
|
let vdso_vmo = vdso_vmo();
|
|
|
|
let options = root_vmar
|
|
.new_map(vdso_vmo.dup().unwrap(), VmPerms::empty())
|
|
.unwrap()
|
|
.size(5 * PAGE_SIZE);
|
|
let vdso_data_base = options.build().unwrap();
|
|
let vdso_text_base = vdso_data_base + 0x4000;
|
|
|
|
let data_perms = VmPerms::READ | VmPerms::WRITE;
|
|
let text_perms = VmPerms::READ | VmPerms::EXEC;
|
|
root_vmar
|
|
.protect(data_perms, vdso_data_base..vdso_data_base + PAGE_SIZE)
|
|
.unwrap();
|
|
root_vmar
|
|
.protect(text_perms, vdso_text_base..vdso_text_base + PAGE_SIZE)
|
|
.unwrap();
|
|
vdso_text_base
|
|
}
|
|
|
|
/// Load an executable to root vmar, including loading programe image, preparing heap and stack,
|
|
/// initializing argv, envp and aux tables.
|
|
/// About recursion_limit: recursion limit is used to limit th recursion depth of shebang executables.
|
|
/// If the interpreter(the program behind #!) of shebang executable is also a shebang,
|
|
/// then it will trigger recursion. We will try to setup root vmar for the interpreter.
|
|
/// I guess for most cases, setting the recursion_limit as 1 should be enough.
|
|
/// because the interpreter is usually an elf binary(e.g., /bin/bash)
|
|
pub fn load_program_to_vm(
|
|
process_vm: &ProcessVm,
|
|
elf_file: Arc<Dentry>,
|
|
argv: Vec<CString>,
|
|
envp: Vec<CString>,
|
|
fs_resolver: &FsResolver,
|
|
recursion_limit: usize,
|
|
) -> Result<(String, ElfLoadInfo)> {
|
|
let abs_path = elf_file.abs_path();
|
|
let inode = elf_file.inode();
|
|
let file_header = {
|
|
// read the first page of file header
|
|
let mut file_header_buffer = Box::new([0u8; PAGE_SIZE]);
|
|
inode.read_at(0, &mut *file_header_buffer)?;
|
|
file_header_buffer
|
|
};
|
|
if let Some(mut new_argv) = parse_shebang_line(&*file_header)? {
|
|
if recursion_limit == 0 {
|
|
return_errno_with_message!(Errno::ELOOP, "the recursieve limit is reached");
|
|
}
|
|
new_argv.extend_from_slice(&argv);
|
|
let interpreter = {
|
|
let filename = new_argv[0].to_str()?.to_string();
|
|
let fs_path = FsPath::new(AT_FDCWD, &filename)?;
|
|
fs_resolver.lookup(&fs_path)?
|
|
};
|
|
check_executable_file(&interpreter)?;
|
|
return load_program_to_vm(
|
|
process_vm,
|
|
interpreter,
|
|
new_argv,
|
|
envp,
|
|
fs_resolver,
|
|
recursion_limit - 1,
|
|
);
|
|
}
|
|
process_vm.clear();
|
|
let vdso_text_base = map_vdso_to_vm(process_vm);
|
|
let elf_load_info = load_elf_to_vm(
|
|
process_vm,
|
|
&*file_header,
|
|
elf_file,
|
|
fs_resolver,
|
|
argv,
|
|
envp,
|
|
vdso_text_base,
|
|
)?;
|
|
|
|
Ok((abs_path, elf_load_info))
|
|
}
|
|
|
|
pub fn check_executable_file(dentry: &Arc<Dentry>) -> Result<()> {
|
|
if dentry.inode_type().is_directory() {
|
|
return_errno_with_message!(Errno::EISDIR, "the file is a directory");
|
|
}
|
|
|
|
if !dentry.inode_type().is_reguler_file() {
|
|
return_errno_with_message!(Errno::EACCES, "the dentry is not a regular file");
|
|
}
|
|
|
|
if !dentry.inode_mode().is_executable() {
|
|
return_errno_with_message!(Errno::EACCES, "the dentry is not executable");
|
|
}
|
|
|
|
Ok(())
|
|
}
|