-use std::mem;
+use std::{mem, iter};
+use std::ffi::{OsStr, OsString};
-use rustc::ty::{self, layout::{self, Size, Align}};
use rustc::hir::def_id::{DefId, CRATE_DEF_INDEX};
use rustc::mir;
+use rustc::ty::{
+ self,
+ layout::{self, LayoutOf, Size, TyLayout},
+};
use rand::RngCore;
/// Test if this immediate equals 0.
fn is_null(&self, val: Scalar<Tag>) -> InterpResult<'tcx, bool> {
let this = self.eval_context_ref();
- let null = Scalar::from_int(0, this.memory().pointer_size());
+ let null = Scalar::from_int(0, this.memory.pointer_size());
this.ptr_eq(val, null)
}
/// Get the `Place` for a local
fn local_place(&mut self, local: mir::Local) -> InterpResult<'tcx, PlaceTy<'tcx, Tag>> {
let this = self.eval_context_mut();
- let place = mir::Place { base: mir::PlaceBase::Local(local), projection: None };
+ let place = mir::Place { base: mir::PlaceBase::Local(local), projection: Box::new([]) };
this.eval_place(&place)
}
ptr: Scalar<Tag>,
len: usize,
) -> InterpResult<'tcx> {
+ // Some programs pass in a null pointer and a length of 0
+ // to their platform's random-generation function (e.g. getrandom())
+ // on Linux. For compatibility with these programs, we don't perform
+ // any additional checks - it's okay if the pointer is invalid,
+ // since we wouldn't actually be writing to it.
+ if len == 0 {
+ return Ok(());
+ }
let this = self.eval_context_mut();
- let ptr = match this.memory().check_ptr_access(ptr, Size::from_bytes(len as u64), Align::from_bytes(1).unwrap())? {
- Some(ptr) => ptr,
- None => return Ok(()), // zero-sized access
- };
-
- let rng = this.memory_mut().extra.rng.get_mut();
let mut data = vec![0; len];
- rng.fill_bytes(&mut data);
- let tcx = &{this.tcx.tcx};
- this.memory_mut().get_mut(ptr.alloc_id)?.write_bytes(tcx, ptr, &data)
+ if this.machine.communicate {
+ // Fill the buffer using the host's rng.
+ getrandom::getrandom(&mut data)
+ .map_err(|err| err_unsup_format!("getrandom failed: {}", err))?;
+ }
+ else {
+ let rng = this.memory.extra.rng.get_mut();
+ rng.fill_bytes(&mut data);
+ }
+
+ this.memory.write_bytes(ptr, data.iter().copied())
}
/// Visits the memory covered by `place`, sensitive to freezing: the 3rd parameter
fn visit_value(&mut self, v: MPlaceTy<'tcx, Tag>) -> InterpResult<'tcx>
{
trace!("UnsafeCellVisitor: {:?} {:?}", *v, v.layout.ty);
- let is_unsafe_cell = match v.layout.ty.sty {
+ let is_unsafe_cell = match v.layout.ty.kind {
ty::Adt(adt, _) => Some(adt.did) == self.ecx.tcx.lang_items().unsafe_cell_type(),
_ => false,
};
// This is `Freeze`, there cannot be an `UnsafeCell`
Ok(())
} else {
- // Proceed further
- self.walk_value(v)
+ // We want to not actually read from memory for this visit. So, before
+ // walking this value, we have to make sure it is not a
+ // `Variants::Multiple`.
+ match v.layout.variants {
+ layout::Variants::Multiple { .. } => {
+ // A multi-variant enum, or generator, or so.
+ // Treat this like a union: without reading from memory,
+ // we cannot determine the variant we are in. Reading from
+ // memory would be subject to Stacked Borrows rules, leading
+ // to all sorts of "funny" recursion.
+ // We only end up here if the type is *not* freeze, so we just call the
+ // `UnsafeCell` action.
+ (self.unsafe_cell_action)(v)
+ }
+ layout::Variants::Single { .. } => {
+ // Proceed further, try to find where exactly that `UnsafeCell`
+ // is hiding.
+ self.walk_value(v)
+ }
+ }
}
}
}
}
}
+
+ /// Helper function to get a `libc` constant as a `Scalar`.
+ fn eval_libc(&mut self, name: &str) -> InterpResult<'tcx, Scalar<Tag>> {
+ self.eval_context_mut()
+ .eval_path_scalar(&["libc", name])?
+ .ok_or_else(|| err_unsup_format!("Path libc::{} cannot be resolved.", name))?
+ .not_undef()
+ }
+
+ /// Helper function to get a `libc` constant as an `i32`.
+ fn eval_libc_i32(&mut self, name: &str) -> InterpResult<'tcx, i32> {
+ self.eval_libc(name)?.to_i32()
+ }
+
+ /// Helper function to get the `TyLayout` of a `libc` type
+ fn libc_ty_layout(&mut self, name: &str) -> InterpResult<'tcx, TyLayout<'tcx>> {
+ let this = self.eval_context_mut();
+ let ty = this.resolve_path(&["libc", name])?.ty(*this.tcx);
+ this.layout_of(ty)
+ }
+
+ // Writes several `ImmTy`s contiguosly into memory. This is useful when you have to pack
+ // different values into a struct.
+ fn write_packed_immediates(
+ &mut self,
+ place: &MPlaceTy<'tcx, Tag>,
+ imms: &[ImmTy<'tcx, Tag>],
+ ) -> InterpResult<'tcx> {
+ let this = self.eval_context_mut();
+
+ let mut offset = Size::from_bytes(0);
+
+ for &imm in imms {
+ this.write_immediate_to_mplace(
+ *imm,
+ place.offset(offset, None, imm.layout, &*this.tcx)?,
+ )?;
+ offset += imm.layout.size;
+ }
+ Ok(())
+ }
+
+ /// Helper function used inside the shims of foreign functions to check that isolation is
+ /// disabled. It returns an error using the `name` of the foreign function if this is not the
+ /// case.
+ fn check_no_isolation(&mut self, name: &str) -> InterpResult<'tcx> {
+ if !self.eval_context_mut().machine.communicate {
+ throw_unsup_format!("`{}` not available when isolation is enabled. Pass the flag `-Zmiri-disable-isolation` to disable it.", name)
+ }
+ Ok(())
+ }
+
+ /// Sets the last error variable.
+ fn set_last_error(&mut self, scalar: Scalar<Tag>) -> InterpResult<'tcx> {
+ let this = self.eval_context_mut();
+ let errno_place = this.machine.last_error.unwrap();
+ this.write_scalar(scalar, errno_place.into())
+ }
+
+ /// Gets the last error variable.
+ fn get_last_error(&mut self) -> InterpResult<'tcx, Scalar<Tag>> {
+ let this = self.eval_context_mut();
+ let errno_place = this.machine.last_error.unwrap();
+ this.read_scalar(errno_place.into())?.not_undef()
+ }
+
+ /// Sets the last OS error using a `std::io::Error`. This function tries to produce the most
+ /// similar OS error from the `std::io::ErrorKind` and sets it as the last OS error.
+ fn set_last_error_from_io_error(&mut self, e: std::io::Error) -> InterpResult<'tcx> {
+ use std::io::ErrorKind::*;
+ let this = self.eval_context_mut();
+ let target = &this.tcx.tcx.sess.target.target;
+ let last_error = if target.options.target_family == Some("unix".to_owned()) {
+ this.eval_libc(match e.kind() {
+ ConnectionRefused => "ECONNREFUSED",
+ ConnectionReset => "ECONNRESET",
+ PermissionDenied => "EPERM",
+ BrokenPipe => "EPIPE",
+ NotConnected => "ENOTCONN",
+ ConnectionAborted => "ECONNABORTED",
+ AddrNotAvailable => "EADDRNOTAVAIL",
+ AddrInUse => "EADDRINUSE",
+ NotFound => "ENOENT",
+ Interrupted => "EINTR",
+ InvalidInput => "EINVAL",
+ TimedOut => "ETIMEDOUT",
+ AlreadyExists => "EEXIST",
+ WouldBlock => "EWOULDBLOCK",
+ _ => throw_unsup_format!("The {} error cannot be transformed into a raw os error", e)
+ })?
+ } else {
+ // FIXME: we have to implement the windows' equivalent of this.
+ throw_unsup_format!("Setting the last OS error from an io::Error is unsupported for {}.", target.target_os)
+ };
+ this.set_last_error(last_error)
+ }
+
+ /// Helper function that consumes an `std::io::Result<T>` and returns an
+ /// `InterpResult<'tcx,T>::Ok` instead. In case the result is an error, this function returns
+ /// `Ok(-1)` and sets the last OS error accordingly.
+ ///
+ /// This function uses `T: From<i32>` instead of `i32` directly because some IO related
+ /// functions return different integer types (like `read`, that returns an `i64`)
+ fn try_unwrap_io_result<T: From<i32>>(
+ &mut self,
+ result: std::io::Result<T>,
+ ) -> InterpResult<'tcx, T> {
+ match result {
+ Ok(ok) => Ok(ok),
+ Err(e) => {
+ self.eval_context_mut().set_last_error_from_io_error(e)?;
+ Ok((-1).into())
+ }
+ }
+ }
+
+ /// Helper function to read an OsString from a null-terminated sequence of bytes, which is what
+ /// the Unix APIs usually handle.
+ fn read_os_string_from_c_string(&mut self, scalar: Scalar<Tag>) -> InterpResult<'tcx, OsString> {
+ let bytes = self.eval_context_mut().memory.read_c_str(scalar)?;
+ Ok(bytes_to_os_str(bytes)?.into())
+ }
+
+ /// Helper function to write an OsStr as a null-terminated sequence of bytes, which is what
+ /// the Unix APIs usually handle. This function returns `Ok(false)` without trying to write if
+ /// `size` is not large enough to fit the contents of `os_string` plus a null terminator. It
+ /// returns `Ok(true)` if the writing process was successful.
+ fn write_os_str_to_c_string(
+ &mut self,
+ os_str: &OsStr,
+ scalar: Scalar<Tag>,
+ size: u64
+ ) -> InterpResult<'tcx, bool> {
+ let bytes = os_str_to_bytes(os_str)?;
+ // If `size` is smaller or equal than `bytes.len()`, writing `bytes` plus the required null
+ // terminator to memory using the `ptr` pointer would cause an overflow.
+ if size <= bytes.len() as u64 {
+ return Ok(false);
+ }
+ // FIXME: We should use `Iterator::chain` instead when rust-lang/rust#65704 lands.
+ self.eval_context_mut().memory.write_bytes(scalar, bytes.iter().copied().chain(iter::once(0u8)))?;
+ Ok(true)
+ }
+}
+
+#[cfg(target_os = "unix")]
+fn os_str_to_bytes<'tcx, 'a>(os_str: &'a OsStr) -> InterpResult<'tcx, &'a [u8]> {
+ std::os::unix::ffi::OsStringExt::into_bytes(os_str)
+}
+
+#[cfg(target_os = "unix")]
+fn bytes_to_os_str<'tcx, 'a>(bytes: &'a[u8]) -> InterpResult<'tcx, &'a OsStr> {
+ Ok(std::os::unix::ffi::OsStringExt::from_bytes(bytes))
+}
+
+// On non-unix platforms the best we can do to transform bytes from/to OS strings is to do the
+// intermediate transformation into strings. Which invalidates non-utf8 paths that are actually
+// valid.
+#[cfg(not(target_os = "unix"))]
+fn os_str_to_bytes<'tcx, 'a>(os_str: &'a OsStr) -> InterpResult<'tcx, &'a [u8]> {
+ os_str
+ .to_str()
+ .map(|s| s.as_bytes())
+ .ok_or_else(|| err_unsup_format!("{:?} is not a valid utf-8 string", os_str).into())
+}
+
+#[cfg(not(target_os = "unix"))]
+fn bytes_to_os_str<'tcx, 'a>(bytes: &'a[u8]) -> InterpResult<'tcx, &'a OsStr> {
+ let s = std::str::from_utf8(bytes)
+ .map_err(|_| err_unsup_format!("{:?} is not a valid utf-8 string", bytes))?;
+ Ok(&OsStr::new(s))
}
projects / rust.git / blobdiff