rust/src/shims/fs.rs

789 lines
32 KiB
Rust
Raw Normal View History

2019-09-24 17:28:00 -05:00
use std::collections::HashMap;
2019-12-23 05:56:23 -06:00
use std::convert::{TryFrom, TryInto};
2020-01-26 16:45:05 -06:00
use std::fs::{remove_file, rename, File, OpenOptions};
2020-01-26 12:36:36 -06:00
use std::io::{Read, Seek, SeekFrom, Write};
2019-11-30 14:09:52 -06:00
use std::path::PathBuf;
use std::time::SystemTime;
2019-09-24 17:28:00 -05:00
2019-12-23 05:56:23 -06:00
use rustc::ty::layout::{Align, LayoutOf, Size};
2019-09-30 14:21:45 -05:00
2019-09-24 17:28:00 -05:00
use crate::stacked_borrows::Tag;
use crate::*;
2019-11-30 14:09:52 -06:00
use helpers::immty_from_uint_checked;
use shims::time::system_time_to_duration;
2019-09-24 17:28:00 -05:00
#[derive(Debug)]
2019-09-30 15:18:23 -05:00
pub struct FileHandle {
2019-09-30 11:51:09 -05:00
file: File,
2019-12-30 16:26:17 -06:00
writable: bool,
2019-09-30 11:51:09 -05:00
}
2019-09-24 17:28:00 -05:00
pub struct FileHandler {
2019-09-30 11:51:09 -05:00
handles: HashMap<i32, FileHandle>,
2019-09-24 17:28:00 -05:00
low: i32,
}
2020-01-30 18:38:30 -06:00
impl FileHandler {
fn next_fd(&self) -> i32 {
self.low + 1
}
fn register_fd(&mut self, fd: i32, handle: FileHandle) {
self.low = fd;
self.handles.insert(fd, handle).unwrap_none();
}
}
impl Default for FileHandler {
fn default() -> Self {
FileHandler {
2019-09-30 11:51:09 -05:00
handles: Default::default(),
// 0, 1 and 2 are reserved for stdin, stdout and stderr.
low: 2,
}
}
}
2019-09-24 17:28:00 -05:00
impl<'mir, 'tcx> EvalContextExt<'mir, 'tcx> for crate::MiriEvalContext<'mir, 'tcx> {}
pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx> {
fn open(
&mut self,
path_op: OpTy<'tcx, Tag>,
flag_op: OpTy<'tcx, Tag>,
) -> InterpResult<'tcx, i32> {
let this = self.eval_context_mut();
this.check_no_isolation("open")?;
2019-09-24 17:28:00 -05:00
let flag = this.read_scalar(flag_op)?.to_i32()?;
2019-09-30 11:46:07 -05:00
let mut options = OpenOptions::new();
let o_rdonly = this.eval_libc_i32("O_RDONLY")?;
let o_wronly = this.eval_libc_i32("O_WRONLY")?;
let o_rdwr = this.eval_libc_i32("O_RDWR")?;
// The first two bits of the flag correspond to the access mode in linux, macOS and
// windows. We need to check that in fact the access mode flags for the current platform
// only use these two bits, otherwise we are in an unsupported platform and should error.
if (o_rdonly | o_wronly | o_rdwr) & !0b11 != 0 {
throw_unsup_format!("Access mode flags on this platform are unsupported");
}
2019-12-30 16:26:17 -06:00
let mut writable = true;
// Now we check the access mode
2019-09-30 11:46:07 -05:00
let access_mode = flag & 0b11;
if access_mode == o_rdonly {
2019-12-30 16:26:17 -06:00
writable = false;
2019-09-30 11:46:07 -05:00
options.read(true);
} else if access_mode == o_wronly {
2019-09-30 11:46:07 -05:00
options.write(true);
} else if access_mode == o_rdwr {
2019-09-30 11:46:07 -05:00
options.read(true).write(true);
} else {
throw_unsup_format!("Unsupported access mode {:#x}", access_mode);
}
// We need to check that there aren't unsupported options in `flag`. For this we try to
// reproduce the content of `flag` in the `mirror` variable using only the supported
// options.
let mut mirror = access_mode;
2019-09-30 11:46:07 -05:00
let o_append = this.eval_libc_i32("O_APPEND")?;
if flag & o_append != 0 {
2019-09-30 11:46:07 -05:00
options.append(true);
mirror |= o_append;
2019-09-30 11:46:07 -05:00
}
let o_trunc = this.eval_libc_i32("O_TRUNC")?;
if flag & o_trunc != 0 {
2019-09-30 11:46:07 -05:00
options.truncate(true);
mirror |= o_trunc;
2019-09-30 11:46:07 -05:00
}
let o_creat = this.eval_libc_i32("O_CREAT")?;
if flag & o_creat != 0 {
2019-09-30 11:46:07 -05:00
options.create(true);
mirror |= o_creat;
}
let o_cloexec = this.eval_libc_i32("O_CLOEXEC")?;
if flag & o_cloexec != 0 {
2019-10-12 20:12:26 -05:00
// We do not need to do anything for this flag because `std` already sets it.
// (Technically we do not support *not* setting this flag, but we ignore that.)
mirror |= o_cloexec;
}
// If `flag` is not equal to `mirror`, there is an unsupported option enabled in `flag`,
// then we throw an error.
if flag != mirror {
2019-10-12 20:12:26 -05:00
throw_unsup_format!("unsupported flags {:#x}", flag & !mirror);
2019-09-24 17:28:00 -05:00
}
2019-12-04 03:43:36 -06:00
let path = this.read_os_str_from_c_str(this.read_scalar(path_op)?.not_undef()?)?;
2019-09-30 11:46:07 -05:00
2019-11-30 14:09:52 -06:00
let fd = options.open(&path).map(|file| {
2020-01-30 18:38:30 -06:00
let fh = &mut this.machine.file_handler;
let fd = fh.next_fd();
fh.register_fd(fd, FileHandle { file, writable });
fd
2019-09-30 14:07:08 -05:00
});
2019-10-18 14:33:25 -05:00
this.try_unwrap_io_result(fd)
2019-09-24 17:28:00 -05:00
}
fn fcntl(
&mut self,
fd_op: OpTy<'tcx, Tag>,
cmd_op: OpTy<'tcx, Tag>,
arg_op: Option<OpTy<'tcx, Tag>>,
2019-09-24 17:28:00 -05:00
) -> InterpResult<'tcx, i32> {
let this = self.eval_context_mut();
this.check_no_isolation("fcntl")?;
2019-09-24 17:28:00 -05:00
let fd = this.read_scalar(fd_op)?.to_i32()?;
let cmd = this.read_scalar(cmd_op)?.to_i32()?;
// We only support getting the flags for a descriptor.
2019-10-11 12:17:54 -05:00
if cmd == this.eval_libc_i32("F_GETFD")? {
2019-10-12 20:12:26 -05:00
// Currently this is the only flag that `F_GETFD` returns. It is OK to just return the
// `FD_CLOEXEC` value without checking if the flag is set for the file because `std`
// always sets this flag when opening a file. However we still need to check that the
// file itself is open.
2019-10-24 08:44:13 -05:00
if this.machine.file_handler.handles.contains_key(&fd) {
Ok(this.eval_libc_i32("FD_CLOEXEC")?)
} else {
this.handle_not_found()
}
} else if cmd == this.eval_libc_i32("F_DUPFD")? || cmd == this.eval_libc_i32("F_DUPFD_CLOEXEC")? {
2020-01-28 23:18:09 -06:00
// Note that we always assume the FD_CLOEXEC flag is set for every open file, in part
// because exec() isn't supported. The F_DUPFD and F_DUPFD_CLOEXEC commands only
2020-01-30 18:31:34 -06:00
// differ in whether the FD_CLOEXEC flag is pre-set on the new file descriptor,
2020-01-28 23:18:09 -06:00
// thus they can share the same implementation here.
2020-01-30 18:31:34 -06:00
let arg_op = arg_op
.ok_or_else(|| err_unsup_format!("fcntl with command F_DUPFD or F_DUPFD_CLOEXEC requires a third argument"))?;
let arg = this.read_scalar(arg_op)?.to_i32()?;
let fh = &mut this.machine.file_handler;
let (file_result, writable) = match fh.handles.get(&fd) {
Some(original) => (original.file.try_clone(), original.writable),
None => return this.handle_not_found(),
};
let fd_result = file_result.map(|duplicated| {
2020-01-30 18:38:30 -06:00
let new_fd = std::cmp::max(fh.next_fd(), arg);
fh.register_fd(new_fd, FileHandle { file: duplicated, writable });
new_fd
});
this.try_unwrap_io_result(fd_result)
2019-09-24 17:28:00 -05:00
} else {
2019-10-11 12:17:54 -05:00
throw_unsup_format!("The {:#x} command is not supported for `fcntl`)", cmd);
2019-09-24 17:28:00 -05:00
}
}
fn close(&mut self, fd_op: OpTy<'tcx, Tag>) -> InterpResult<'tcx, i32> {
let this = self.eval_context_mut();
this.check_no_isolation("close")?;
2019-09-24 17:28:00 -05:00
let fd = this.read_scalar(fd_op)?.to_i32()?;
2019-10-24 08:44:13 -05:00
if let Some(handle) = this.machine.file_handler.handles.remove(&fd) {
2019-12-27 08:11:21 -06:00
// We sync the file if it was opened in a mode different than read-only.
2019-12-30 16:26:17 -06:00
if handle.writable {
2019-12-27 08:11:21 -06:00
// `File::sync_all` does the checks that are done when closing a file. We do this to
// to handle possible errors correctly.
let result = this.try_unwrap_io_result(handle.file.sync_all().map(|_| 0i32));
// Now we actually close the file.
drop(handle);
// And return the result.
result
} else {
// We drop the file, this closes it but ignores any errors produced when closing
// it. This is done because `File::sync_call` cannot be done over files like
2019-12-30 16:26:17 -06:00
// `/dev/urandom` which are read-only. Check
2019-12-27 08:11:21 -06:00
// https://github.com/rust-lang/miri/issues/999#issuecomment-568920439 for a deeper
// discussion.
drop(handle);
Ok(0)
}
2019-10-24 08:44:13 -05:00
} else {
this.handle_not_found()
}
2019-09-24 17:28:00 -05:00
}
fn read(
&mut self,
fd_op: OpTy<'tcx, Tag>,
buf_op: OpTy<'tcx, Tag>,
count_op: OpTy<'tcx, Tag>,
) -> InterpResult<'tcx, i64> {
let this = self.eval_context_mut();
this.check_no_isolation("read")?;
2019-09-24 17:28:00 -05:00
let fd = this.read_scalar(fd_op)?.to_i32()?;
let buf = this.read_scalar(buf_op)?.not_undef()?;
2019-12-23 05:56:23 -06:00
let count = this.read_scalar(count_op)?.to_machine_usize(&*this.tcx)?;
2019-11-14 03:29:43 -06:00
// Check that the *entire* buffer is actually valid memory.
2019-12-23 05:56:23 -06:00
this.memory.check_ptr_access(
buf,
Size::from_bytes(count),
Align::from_bytes(1).unwrap(),
)?;
// We cap the number of read bytes to the largest value that we are able to fit in both the
// host's and target's `isize`. This saves us from having to handle overflows later.
2019-12-23 05:56:23 -06:00
let count = count.min(this.isize_max() as u64).min(isize::max_value() as u64);
2019-10-24 08:44:13 -05:00
if let Some(handle) = this.machine.file_handler.handles.get_mut(&fd) {
2019-11-13 10:57:20 -06:00
// This can never fail because `count` was capped to be smaller than
// `isize::max_value()`.
2019-11-09 08:15:52 -06:00
let count = isize::try_from(count).unwrap();
2019-11-07 13:50:16 -06:00
// We want to read at most `count` bytes. We are sure that `count` is not negative
// because it was a target's `usize`. Also we are sure that its smaller than
// `usize::max_value()` because it is a host's `isize`.
let mut bytes = vec![0; count as usize];
2019-11-09 08:15:52 -06:00
let result = handle
.file
.read(&mut bytes)
2019-11-13 13:45:00 -06:00
// `File::read` never returns a value larger than `count`, so this cannot fail.
2019-11-09 08:15:52 -06:00
.map(|c| i64::try_from(c).unwrap());
2019-10-28 16:44:18 -05:00
2019-11-04 08:38:21 -06:00
match result {
2019-11-09 08:15:52 -06:00
Ok(read_bytes) => {
2019-11-05 15:47:24 -06:00
// If reading to `bytes` did not fail, we write those bytes to the buffer.
this.memory.write_bytes(buf, bytes)?;
Ok(read_bytes)
2019-11-09 08:15:52 -06:00
}
2019-11-04 08:38:21 -06:00
Err(e) => {
this.set_last_error_from_io_error(e)?;
Ok(-1)
2019-10-28 16:44:18 -05:00
}
2019-10-24 08:44:13 -05:00
}
} else {
this.handle_not_found()
}
2019-09-30 15:18:23 -05:00
}
2019-09-30 11:46:07 -05:00
fn write(
&mut self,
fd_op: OpTy<'tcx, Tag>,
buf_op: OpTy<'tcx, Tag>,
count_op: OpTy<'tcx, Tag>,
) -> InterpResult<'tcx, i64> {
let this = self.eval_context_mut();
this.check_no_isolation("write")?;
2019-09-30 11:46:07 -05:00
let fd = this.read_scalar(fd_op)?.to_i32()?;
let buf = this.read_scalar(buf_op)?.not_undef()?;
2019-12-23 05:56:23 -06:00
let count = this.read_scalar(count_op)?.to_machine_usize(&*this.tcx)?;
2019-11-14 03:29:43 -06:00
// Check that the *entire* buffer is actually valid memory.
2019-12-23 05:56:23 -06:00
this.memory.check_ptr_access(
buf,
Size::from_bytes(count),
Align::from_bytes(1).unwrap(),
)?;
// We cap the number of written bytes to the largest value that we are able to fit in both the
// host's and target's `isize`. This saves us from having to handle overflows later.
2019-12-23 05:56:23 -06:00
let count = count.min(this.isize_max() as u64).min(isize::max_value() as u64);
2019-10-24 08:44:13 -05:00
if let Some(handle) = this.machine.file_handler.handles.get_mut(&fd) {
let bytes = this.memory.read_bytes(buf, Size::from_bytes(count))?;
2019-11-09 08:15:52 -06:00
let result = handle.file.write(&bytes).map(|c| i64::try_from(c).unwrap());
this.try_unwrap_io_result(result)
2019-10-24 08:44:13 -05:00
} else {
this.handle_not_found()
}
2019-09-30 11:46:07 -05:00
}
2020-01-26 12:36:36 -06:00
fn lseek64(
&mut self,
fd_op: OpTy<'tcx, Tag>,
offset_op: OpTy<'tcx, Tag>,
whence_op: OpTy<'tcx, Tag>,
) -> InterpResult<'tcx, i64> {
let this = self.eval_context_mut();
this.check_no_isolation("lseek64")?;
let fd = this.read_scalar(fd_op)?.to_i32()?;
let offset = this.read_scalar(offset_op)?.to_i64()?;
let whence = this.read_scalar(whence_op)?.to_i32()?;
let seek_from = if whence == this.eval_libc_i32("SEEK_SET")? {
SeekFrom::Start(offset as u64)
} else if whence == this.eval_libc_i32("SEEK_CUR")? {
SeekFrom::Current(offset)
} else if whence == this.eval_libc_i32("SEEK_END")? {
SeekFrom::End(offset)
} else {
let einval = this.eval_libc("EINVAL")?;
this.set_last_error(einval)?;
return Ok(-1);
2020-01-26 12:36:36 -06:00
};
if let Some(handle) = this.machine.file_handler.handles.get_mut(&fd) {
let result = handle.file.seek(seek_from).map(|offset| offset as i64);
this.try_unwrap_io_result(result)
} else {
this.handle_not_found()
}
}
2019-10-24 08:44:13 -05:00
fn unlink(&mut self, path_op: OpTy<'tcx, Tag>) -> InterpResult<'tcx, i32> {
2019-10-03 09:33:36 -05:00
let this = self.eval_context_mut();
this.check_no_isolation("unlink")?;
2019-10-03 09:33:36 -05:00
2019-12-04 03:43:36 -06:00
let path = this.read_os_str_from_c_str(this.read_scalar(path_op)?.not_undef()?)?;
2019-10-03 09:33:36 -05:00
let result = remove_file(path).map(|_| 0);
2019-10-18 14:33:25 -05:00
this.try_unwrap_io_result(result)
2019-10-03 09:33:36 -05:00
}
2020-01-06 15:30:17 -06:00
fn symlink(
&mut self,
target_op: OpTy<'tcx, Tag>,
linkpath_op: OpTy<'tcx, Tag>
) -> InterpResult<'tcx, i32> {
#[cfg(target_family = "unix")]
fn create_link(src: PathBuf, dst: PathBuf) -> std::io::Result<()> {
std::os::unix::fs::symlink(src, dst)
}
#[cfg(target_family = "windows")]
fn create_link(src: PathBuf, dst: PathBuf) -> std::io::Result<()> {
use std::os::windows::fs;
if src.is_dir() {
fs::symlink_dir(src, dst)
} else {
2020-01-10 11:18:24 -06:00
fs::symlink_file(src, dst)
2020-01-06 15:30:17 -06:00
}
}
let this = self.eval_context_mut();
this.check_no_isolation("symlink")?;
let target = this.read_os_str_from_c_str(this.read_scalar(target_op)?.not_undef()?)?.into();
let linkpath = this.read_os_str_from_c_str(this.read_scalar(linkpath_op)?.not_undef()?)?.into();
this.try_unwrap_io_result(create_link(target, linkpath).map(|_| 0))
}
2019-12-24 10:53:03 -06:00
fn stat(
&mut self,
path_op: OpTy<'tcx, Tag>,
2019-12-24 10:01:01 -06:00
buf_op: OpTy<'tcx, Tag>,
) -> InterpResult<'tcx, i32> {
let this = self.eval_context_mut();
2020-01-07 10:29:25 -06:00
this.check_no_isolation("stat")?;
// `stat` always follows symlinks.
this.stat_or_lstat(true, path_op, buf_op)
}
// `lstat` is used to get symlink metadata.
fn lstat(
&mut self,
path_op: OpTy<'tcx, Tag>,
buf_op: OpTy<'tcx, Tag>,
) -> InterpResult<'tcx, i32> {
let this = self.eval_context_mut();
this.check_no_isolation("lstat")?;
this.stat_or_lstat(false, path_op, buf_op)
}
2020-01-26 11:58:08 -06:00
fn fstat(
&mut self,
fd_op: OpTy<'tcx, Tag>,
buf_op: OpTy<'tcx, Tag>,
) -> InterpResult<'tcx, i32> {
let this = self.eval_context_mut();
this.check_no_isolation("fstat")?;
if this.tcx.sess.target.target.target_os.to_lowercase() != "macos" {
throw_unsup_format!("The `fstat` shim is only available for `macos` targets.")
}
let fd = this.read_scalar(fd_op)?.to_i32()?;
let metadata = match FileMetadata::from_fd(this, fd)? {
Some(metadata) => metadata,
None => return Ok(-1),
};
stat_macos_write_buf(this, metadata, buf_op)
2020-01-26 11:58:08 -06:00
}
2020-01-07 10:29:25 -06:00
fn stat_or_lstat(
&mut self,
follow_symlink: bool,
path_op: OpTy<'tcx, Tag>,
buf_op: OpTy<'tcx, Tag>,
) -> InterpResult<'tcx, i32> {
let this = self.eval_context_mut();
2019-12-24 10:01:01 -06:00
2019-12-25 10:30:01 -06:00
if this.tcx.sess.target.target.target_os.to_lowercase() != "macos" {
2020-01-10 11:01:05 -06:00
throw_unsup_format!("The `stat` and `lstat` shims are only available for `macos` targets.")
2019-12-25 10:30:01 -06:00
}
2019-12-24 10:53:03 -06:00
let path_scalar = this.read_scalar(path_op)?.not_undef()?;
let path: PathBuf = this.read_os_str_from_c_str(path_scalar)?.into();
2019-12-24 10:53:03 -06:00
let metadata = match FileMetadata::from_path(this, path, follow_symlink)? {
2019-12-26 12:30:04 -06:00
Some(metadata) => metadata,
None => return Ok(-1),
2019-12-24 10:53:03 -06:00
};
stat_macos_write_buf(this, metadata, buf_op)
2019-12-24 10:01:01 -06:00
}
2019-11-30 14:09:52 -06:00
fn statx(
&mut self,
2019-12-23 05:56:23 -06:00
dirfd_op: OpTy<'tcx, Tag>, // Should be an `int`
2019-11-30 14:09:52 -06:00
pathname_op: OpTy<'tcx, Tag>, // Should be a `const char *`
2019-12-23 05:56:23 -06:00
flags_op: OpTy<'tcx, Tag>, // Should be an `int`
_mask_op: OpTy<'tcx, Tag>, // Should be an `unsigned int`
statxbuf_op: OpTy<'tcx, Tag>, // Should be a `struct statx *`
2019-11-30 14:09:52 -06:00
) -> InterpResult<'tcx, i32> {
let this = self.eval_context_mut();
this.check_no_isolation("statx")?;
if this.tcx.sess.target.target.target_os.to_lowercase() != "linux" {
2019-12-26 12:30:04 -06:00
throw_unsup_format!("The `statx` shim is only available for `linux` targets.")
}
2019-11-30 14:09:52 -06:00
let statxbuf_scalar = this.read_scalar(statxbuf_op)?.not_undef()?;
let pathname_scalar = this.read_scalar(pathname_op)?.not_undef()?;
// If the statxbuf or pathname pointers are null, the function fails with `EFAULT`.
if this.is_null(statxbuf_scalar)? || this.is_null(pathname_scalar)? {
let efault = this.eval_libc("EFAULT")?;
this.set_last_error(efault)?;
return Ok(-1);
}
// Under normal circumstances, we would use `deref_operand(statxbuf_op)` to produce a
// proper `MemPlace` and then write the results of this function to it. However, the
// `syscall` function is untyped. This means that all the `statx` parameters are provided
// as `isize`s instead of having the proper types. Thus, we have to recover the layout of
// `statxbuf_op` by using the `libc::statx` struct type.
let statxbuf_place = {
// FIXME: This long path is required because `libc::statx` is an struct and also a
// function and `resolve_path` is returning the latter.
let statx_ty = this
.resolve_path(&["libc", "unix", "linux_like", "linux", "gnu", "statx"])?
2020-01-06 13:53:41 -06:00
.monomorphic_ty(*this.tcx);
2019-11-30 14:09:52 -06:00
let statxbuf_ty = this.tcx.mk_mut_ptr(statx_ty);
let statxbuf_layout = this.layout_of(statxbuf_ty)?;
let statxbuf_imm = ImmTy::from_scalar(statxbuf_scalar, statxbuf_layout);
this.ref_to_mplace(statxbuf_imm)?
};
let path: PathBuf = this.read_os_str_from_c_str(pathname_scalar)?.into();
// `flags` should be a `c_int` but the `syscall` function provides an `isize`.
2019-12-23 05:56:23 -06:00
let flags: i32 =
this.read_scalar(flags_op)?.to_machine_isize(&*this.tcx)?.try_into().map_err(|e| {
err_unsup_format!("Failed to convert pointer sized operand to integer: {}", e)
})?;
let empty_path_flag = flags & this.eval_libc("AT_EMPTY_PATH")?.to_i32()? != 0;
2019-11-30 14:09:52 -06:00
// `dirfd` should be a `c_int` but the `syscall` function provides an `isize`.
2019-12-23 05:56:23 -06:00
let dirfd: i32 =
this.read_scalar(dirfd_op)?.to_machine_isize(&*this.tcx)?.try_into().map_err(|e| {
err_unsup_format!("Failed to convert pointer sized operand to integer: {}", e)
})?;
// We only support:
// * interpreting `path` as an absolute directory,
// * interpreting `path` as a path relative to `dirfd` when the latter is `AT_FDCWD`, or
// * interpreting `dirfd` as any file descriptor when `path` is empty and AT_EMPTY_PATH is
// set.
2020-01-28 22:59:28 -06:00
// Other behaviors cannot be tested from `libstd` and thus are not implemented. If you
// found this error, please open an issue reporting it.
if !(
path.is_absolute() ||
dirfd == this.eval_libc_i32("AT_FDCWD")? ||
(path.as_os_str().is_empty() && empty_path_flag)
) {
2019-11-30 14:09:52 -06:00
throw_unsup_format!(
"Using statx is only supported with absolute paths, relative paths with the file \
descriptor `AT_FDCWD`, and empty paths with the `AT_EMPTY_PATH` flag set and any \
file descriptor"
2019-11-30 14:09:52 -06:00
)
}
// the `_mask_op` paramter specifies the file information that the caller requested.
// However `statx` is allowed to return information that was not requested or to not
// return information that was requested. This `mask` represents the information we can
// actually provide in any host platform.
let mut mask =
this.eval_libc("STATX_TYPE")?.to_u32()? | this.eval_libc("STATX_SIZE")?.to_u32()?;
// If the `AT_SYMLINK_NOFOLLOW` flag is set, we query the file's metadata without following
// symbolic links.
2019-12-26 11:12:19 -06:00
let follow_symlink = flags & this.eval_libc("AT_SYMLINK_NOFOLLOW")?.to_i32()? == 0;
2019-11-30 14:09:52 -06:00
// If the path is empty, and the AT_EMPTY_PATH flag is set, we query the open file
// represented by dirfd, whether it's a directory or otherwise.
let metadata = if path.as_os_str().is_empty() && empty_path_flag {
FileMetadata::from_fd(this, dirfd)?
} else {
FileMetadata::from_path(this, path, follow_symlink)?
};
let metadata = match metadata {
2019-12-26 12:30:04 -06:00
Some(metadata) => metadata,
None => return Ok(-1),
2019-11-30 14:09:52 -06:00
};
// The `mode` field specifies the type of the file and the permissions over the file for
// the owner, its group and other users. Given that we can only provide the file type
// without using platform specific methods, we only set the bits corresponding to the file
// type. This should be an `__u16` but `libc` provides its values as `u32`.
2019-12-26 12:30:04 -06:00
let mode: u16 = metadata
.mode
2019-12-23 05:56:23 -06:00
.to_u32()?
.try_into()
.unwrap_or_else(|_| bug!("libc contains bad value for constant"));
2019-11-30 14:09:52 -06:00
2019-12-26 11:12:19 -06:00
// We need to set the corresponding bits of `mask` if the access, creation and modification
// times were available. Otherwise we let them be zero.
2019-12-26 12:30:04 -06:00
let (access_sec, access_nsec) = metadata.accessed.map(|tup| {
mask |= this.eval_libc("STATX_ATIME")?.to_u32()?;
2019-12-25 21:22:25 -06:00
InterpResult::Ok(tup)
}).unwrap_or(Ok((0, 0)))?;
2019-11-30 14:09:52 -06:00
2019-12-26 12:30:04 -06:00
let (created_sec, created_nsec) = metadata.created.map(|tup| {
mask |= this.eval_libc("STATX_BTIME")?.to_u32()?;
2019-12-25 21:22:25 -06:00
InterpResult::Ok(tup)
}).unwrap_or(Ok((0, 0)))?;
2019-11-30 14:09:52 -06:00
2019-12-26 12:30:04 -06:00
let (modified_sec, modified_nsec) = metadata.modified.map(|tup| {
mask |= this.eval_libc("STATX_MTIME")?.to_u32()?;
2019-12-25 21:22:25 -06:00
InterpResult::Ok(tup)
}).unwrap_or(Ok((0, 0)))?;
2019-11-30 14:09:52 -06:00
let __u32_layout = this.libc_ty_layout("__u32")?;
let __u64_layout = this.libc_ty_layout("__u64")?;
let __u16_layout = this.libc_ty_layout("__u16")?;
// Now we transform all this fields into `ImmTy`s and write them to `statxbuf`. We write a
// zero for the unavailable fields.
let imms = [
2019-12-23 05:56:23 -06:00
immty_from_uint_checked(mask, __u32_layout)?, // stx_mask
2019-11-30 14:09:52 -06:00
immty_from_uint_checked(0u128, __u32_layout)?, // stx_blksize
immty_from_uint_checked(0u128, __u64_layout)?, // stx_attributes
immty_from_uint_checked(0u128, __u32_layout)?, // stx_nlink
immty_from_uint_checked(0u128, __u32_layout)?, // stx_uid
immty_from_uint_checked(0u128, __u32_layout)?, // stx_gid
2019-12-23 05:56:23 -06:00
immty_from_uint_checked(mode, __u16_layout)?, // stx_mode
2019-11-30 14:09:52 -06:00
immty_from_uint_checked(0u128, __u16_layout)?, // statx padding
immty_from_uint_checked(0u128, __u64_layout)?, // stx_ino
2019-12-26 12:30:04 -06:00
immty_from_uint_checked(metadata.size, __u64_layout)?, // stx_size
2019-11-30 14:09:52 -06:00
immty_from_uint_checked(0u128, __u64_layout)?, // stx_blocks
immty_from_uint_checked(0u128, __u64_layout)?, // stx_attributes
immty_from_uint_checked(access_sec, __u64_layout)?, // stx_atime.tv_sec
immty_from_uint_checked(access_nsec, __u32_layout)?, // stx_atime.tv_nsec
immty_from_uint_checked(0u128, __u32_layout)?, // statx_timestamp padding
immty_from_uint_checked(created_sec, __u64_layout)?, // stx_btime.tv_sec
immty_from_uint_checked(created_nsec, __u32_layout)?, // stx_btime.tv_nsec
immty_from_uint_checked(0u128, __u32_layout)?, // statx_timestamp padding
immty_from_uint_checked(0u128, __u64_layout)?, // stx_ctime.tv_sec
immty_from_uint_checked(0u128, __u32_layout)?, // stx_ctime.tv_nsec
immty_from_uint_checked(0u128, __u32_layout)?, // statx_timestamp padding
immty_from_uint_checked(modified_sec, __u64_layout)?, // stx_mtime.tv_sec
immty_from_uint_checked(modified_nsec, __u32_layout)?, // stx_mtime.tv_nsec
immty_from_uint_checked(0u128, __u32_layout)?, // statx_timestamp padding
immty_from_uint_checked(0u128, __u64_layout)?, // stx_rdev_major
immty_from_uint_checked(0u128, __u64_layout)?, // stx_rdev_minor
immty_from_uint_checked(0u128, __u64_layout)?, // stx_dev_major
immty_from_uint_checked(0u128, __u64_layout)?, // stx_dev_minor
];
this.write_packed_immediates(statxbuf_place, &imms)?;
2019-11-30 14:09:52 -06:00
Ok(0)
}
2019-10-24 08:44:13 -05:00
/// Function used when a handle is not found inside `FileHandler`. It returns `Ok(-1)`and sets
/// the last OS error to `libc::EBADF` (invalid file descriptor). This function uses
/// `T: From<i32>` instead of `i32` directly because some fs functions return different integer
/// types (like `read`, that returns an `i64`).
fn handle_not_found<T: From<i32>>(&mut self) -> InterpResult<'tcx, T> {
2019-09-30 15:18:23 -05:00
let this = self.eval_context_mut();
2019-10-24 08:44:13 -05:00
let ebadf = this.eval_libc("EBADF")?;
this.set_last_error(ebadf)?;
Ok((-1).into())
2019-09-30 14:07:08 -05:00
}
2020-01-26 16:45:05 -06:00
fn rename(
&mut self,
oldpath_op: OpTy<'tcx, Tag>,
newpath_op: OpTy<'tcx, Tag>,
) -> InterpResult<'tcx, i32> {
let this = self.eval_context_mut();
this.check_no_isolation("rename")?;
let oldpath_scalar = this.read_scalar(oldpath_op)?.not_undef()?;
let newpath_scalar = this.read_scalar(newpath_op)?.not_undef()?;
if this.is_null(oldpath_scalar)? || this.is_null(newpath_scalar)? {
let efault = this.eval_libc("EFAULT")?;
this.set_last_error(efault)?;
return Ok(-1);
}
let oldpath = this.read_os_str_from_c_str(oldpath_scalar)?;
let newpath = this.read_os_str_from_c_str(newpath_scalar)?;
let result = rename(oldpath, newpath).map(|_| 0);
this.try_unwrap_io_result(result)
}
2019-09-24 17:28:00 -05:00
}
2019-11-30 14:09:52 -06:00
2019-12-26 11:12:19 -06:00
/// Extracts the number of seconds and nanoseconds elapsed between `time` and the unix epoch when
/// `time` is Ok. Returns `None` if `time` is an error. Fails if `time` happens before the unix
/// epoch.
fn extract_sec_and_nsec<'tcx>(
time: std::io::Result<SystemTime>
) -> InterpResult<'tcx, Option<(u64, u32)>> {
time.ok().map(|time| {
2019-11-30 14:09:52 -06:00
let duration = system_time_to_duration(&time)?;
Ok((duration.as_secs(), duration.subsec_nanos()))
}).transpose()
}
2019-12-26 12:30:04 -06:00
/// Stores a file's metadata in order to avoid code duplication in the different metadata related
/// shims.
struct FileMetadata {
mode: Scalar<Tag>,
size: u64,
created: Option<(u64, u32)>,
accessed: Option<(u64, u32)>,
modified: Option<(u64, u32)>,
}
2019-12-26 12:30:04 -06:00
impl FileMetadata {
fn from_path<'tcx, 'mir>(
2019-12-25 21:22:25 -06:00
ecx: &mut MiriEvalContext<'mir, 'tcx>,
path: PathBuf,
2019-12-26 11:12:19 -06:00
follow_symlink: bool
2019-12-26 12:30:04 -06:00
) -> InterpResult<'tcx, Option<FileMetadata>> {
2019-12-26 11:12:19 -06:00
let metadata = if follow_symlink {
2019-12-26 12:30:04 -06:00
std::fs::metadata(path)
} else {
std::fs::symlink_metadata(path)
};
FileMetadata::from_meta(ecx, metadata)
}
fn from_fd<'tcx, 'mir>(
ecx: &mut MiriEvalContext<'mir, 'tcx>,
fd: i32,
) -> InterpResult<'tcx, Option<FileMetadata>> {
let option = ecx.machine.file_handler.handles.get(&fd);
let handle = match option {
Some(handle) => handle,
None => return ecx.handle_not_found().map(|_: i32| None),
};
let metadata = handle.file.metadata();
FileMetadata::from_meta(ecx, metadata)
}
fn from_meta<'tcx, 'mir>(
ecx: &mut MiriEvalContext<'mir, 'tcx>,
metadata: Result<std::fs::Metadata, std::io::Error>,
) -> InterpResult<'tcx, Option<FileMetadata>> {
let metadata = match metadata {
Ok(metadata) => metadata,
Err(e) => {
ecx.set_last_error_from_io_error(e)?;
return Ok(None);
}
};
let file_type = metadata.file_type();
let mode_name = if file_type.is_file() {
"S_IFREG"
} else if file_type.is_dir() {
"S_IFDIR"
} else {
"S_IFLNK"
};
let mode = ecx.eval_libc(mode_name)?;
let size = metadata.len();
let created = extract_sec_and_nsec(metadata.created())?;
let accessed = extract_sec_and_nsec(metadata.accessed())?;
let modified = extract_sec_and_nsec(metadata.modified())?;
// FIXME: Provide more fields using platform specific methods.
2019-12-26 12:30:04 -06:00
Ok(Some(FileMetadata { mode, size, created, accessed, modified }))
2019-11-30 14:09:52 -06:00
}
}
2020-01-26 11:58:08 -06:00
fn stat_macos_write_buf<'tcx, 'mir>(
2020-01-26 11:58:08 -06:00
ecx: &mut MiriEvalContext<'mir, 'tcx>,
metadata: FileMetadata,
buf_op: OpTy<'tcx, Tag>,
) -> InterpResult<'tcx, i32> {
let mode: u16 = metadata.mode.to_u16()?;
let (access_sec, access_nsec) = metadata.accessed.unwrap_or((0, 0));
let (created_sec, created_nsec) = metadata.created.unwrap_or((0, 0));
let (modified_sec, modified_nsec) = metadata.modified.unwrap_or((0, 0));
let dev_t_layout = ecx.libc_ty_layout("dev_t")?;
let mode_t_layout = ecx.libc_ty_layout("mode_t")?;
let nlink_t_layout = ecx.libc_ty_layout("nlink_t")?;
let ino_t_layout = ecx.libc_ty_layout("ino_t")?;
let uid_t_layout = ecx.libc_ty_layout("uid_t")?;
let gid_t_layout = ecx.libc_ty_layout("gid_t")?;
let time_t_layout = ecx.libc_ty_layout("time_t")?;
let long_layout = ecx.libc_ty_layout("c_long")?;
let off_t_layout = ecx.libc_ty_layout("off_t")?;
let blkcnt_t_layout = ecx.libc_ty_layout("blkcnt_t")?;
let blksize_t_layout = ecx.libc_ty_layout("blksize_t")?;
let uint32_t_layout = ecx.libc_ty_layout("uint32_t")?;
// We need to add 32 bits of padding after `st_rdev` if we are on a 64-bit platform.
let pad_layout = if ecx.tcx.sess.target.ptr_width == 64 {
uint32_t_layout
} else {
ecx.layout_of(ecx.tcx.mk_unit())?
};
let imms = [
immty_from_uint_checked(0u128, dev_t_layout)?, // st_dev
immty_from_uint_checked(mode, mode_t_layout)?, // st_mode
immty_from_uint_checked(0u128, nlink_t_layout)?, // st_nlink
immty_from_uint_checked(0u128, ino_t_layout)?, // st_ino
immty_from_uint_checked(0u128, uid_t_layout)?, // st_uid
immty_from_uint_checked(0u128, gid_t_layout)?, // st_gid
immty_from_uint_checked(0u128, dev_t_layout)?, // st_rdev
immty_from_uint_checked(0u128, pad_layout)?, // padding for 64-bit targets
immty_from_uint_checked(access_sec, time_t_layout)?, // st_atime
immty_from_uint_checked(access_nsec, long_layout)?, // st_atime_nsec
immty_from_uint_checked(modified_sec, time_t_layout)?, // st_mtime
immty_from_uint_checked(modified_nsec, long_layout)?, // st_mtime_nsec
immty_from_uint_checked(0u128, time_t_layout)?, // st_ctime
immty_from_uint_checked(0u128, long_layout)?, // st_ctime_nsec
immty_from_uint_checked(created_sec, time_t_layout)?, // st_birthtime
immty_from_uint_checked(created_nsec, long_layout)?, // st_birthtime_nsec
immty_from_uint_checked(metadata.size, off_t_layout)?, // st_size
immty_from_uint_checked(0u128, blkcnt_t_layout)?, // st_blocks
immty_from_uint_checked(0u128, blksize_t_layout)?, // st_blksize
immty_from_uint_checked(0u128, uint32_t_layout)?, // st_flags
immty_from_uint_checked(0u128, uint32_t_layout)?, // st_gen
];
let buf = ecx.deref_operand(buf_op)?;
ecx.write_packed_immediates(buf, &imms)?;
2020-01-26 11:58:08 -06:00
Ok(0)
}