| //! Global machine state as well as implementation of the interpreter engine |
| //! `Machine` trait. |
| |
| use std::any::Any; |
| use std::borrow::Cow; |
| use std::cell::RefCell; |
| use std::collections::hash_map::Entry; |
| use std::path::Path; |
| use std::{fmt, process}; |
| |
| use rand::rngs::StdRng; |
| use rand::{Rng, SeedableRng}; |
| use rustc_abi::{Align, ExternAbi, Size}; |
| use rustc_attr::InlineAttr; |
| use rustc_data_structures::fx::{FxHashMap, FxHashSet}; |
| #[allow(unused)] |
| use rustc_data_structures::static_assert_size; |
| use rustc_middle::mir; |
| use rustc_middle::query::TyCtxtAt; |
| use rustc_middle::ty::layout::{HasTyCtxt, LayoutCx, LayoutError, LayoutOf, TyAndLayout}; |
| use rustc_middle::ty::{self, Instance, Ty, TyCtxt}; |
| use rustc_session::config::InliningThreshold; |
| use rustc_span::def_id::{CrateNum, DefId}; |
| use rustc_span::{Span, SpanData, Symbol}; |
| |
| use crate::concurrency::cpu_affinity::{self, CpuAffinityMask}; |
| use crate::concurrency::data_race::{self, NaReadType, NaWriteType}; |
| use crate::concurrency::weak_memory; |
| use crate::*; |
| |
| /// First real-time signal. |
| /// `signal(7)` says this must be between 32 and 64 and specifies 34 or 35 |
| /// as typical values. |
| pub const SIGRTMIN: i32 = 34; |
| |
| /// Last real-time signal. |
| /// `signal(7)` says it must be between 32 and 64 and specifies |
| /// `SIGRTMAX` - `SIGRTMIN` >= 8 (which is the value of `_POSIX_RTSIG_MAX`) |
| pub const SIGRTMAX: i32 = 42; |
| |
| /// Each anonymous global (constant, vtable, function pointer, ...) has multiple addresses, but only |
| /// this many. Since const allocations are never deallocated, choosing a new [`AllocId`] and thus |
| /// base address for each evaluation would produce unbounded memory usage. |
| const ADDRS_PER_ANON_GLOBAL: usize = 32; |
| |
| /// Extra data stored with each stack frame |
| pub struct FrameExtra<'tcx> { |
| /// Extra data for the Borrow Tracker. |
| pub borrow_tracker: Option<borrow_tracker::FrameState>, |
| |
| /// If this is Some(), then this is a special "catch unwind" frame (the frame of `try_fn` |
| /// called by `try`). When this frame is popped during unwinding a panic, |
| /// we stop unwinding, use the `CatchUnwindData` to handle catching. |
| pub catch_unwind: Option<CatchUnwindData<'tcx>>, |
| |
| /// If `measureme` profiling is enabled, holds timing information |
| /// for the start of this frame. When we finish executing this frame, |
| /// we use this to register a completed event with `measureme`. |
| pub timing: Option<measureme::DetachedTiming>, |
| |
| /// Indicates whether a `Frame` is part of a workspace-local crate and is also not |
| /// `#[track_caller]`. We compute this once on creation and store the result, as an |
| /// optimization. |
| /// This is used by `MiriMachine::current_span` and `MiriMachine::caller_span` |
| pub is_user_relevant: bool, |
| |
| /// We have a cache for the mapping from [`mir::Const`] to resulting [`AllocId`]. |
| /// However, we don't want all frames to always get the same result, so we insert |
| /// an additional bit of "salt" into the cache key. This salt is fixed per-frame |
| /// so that within a call, a const will have a stable address. |
| salt: usize, |
| |
| /// Data race detector per-frame data. |
| pub data_race: Option<data_race::FrameState>, |
| } |
| |
| impl<'tcx> std::fmt::Debug for FrameExtra<'tcx> { |
| fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result { |
| // Omitting `timing`, it does not support `Debug`. |
| let FrameExtra { |
| borrow_tracker, |
| catch_unwind, |
| timing: _, |
| is_user_relevant, |
| salt, |
| data_race, |
| } = self; |
| f.debug_struct("FrameData") |
| .field("borrow_tracker", borrow_tracker) |
| .field("catch_unwind", catch_unwind) |
| .field("is_user_relevant", is_user_relevant) |
| .field("salt", salt) |
| .field("data_race", data_race) |
| .finish() |
| } |
| } |
| |
| impl VisitProvenance for FrameExtra<'_> { |
| fn visit_provenance(&self, visit: &mut VisitWith<'_>) { |
| let FrameExtra { |
| catch_unwind, |
| borrow_tracker, |
| timing: _, |
| is_user_relevant: _, |
| salt: _, |
| data_race: _, |
| } = self; |
| |
| catch_unwind.visit_provenance(visit); |
| borrow_tracker.visit_provenance(visit); |
| } |
| } |
| |
| /// Extra memory kinds |
| #[derive(Debug, Copy, Clone, PartialEq, Eq)] |
| pub enum MiriMemoryKind { |
| /// `__rust_alloc` memory. |
| Rust, |
| /// `miri_alloc` memory. |
| Miri, |
| /// `malloc` memory. |
| C, |
| /// Windows `HeapAlloc` memory. |
| WinHeap, |
| /// Windows "local" memory (to be freed with `LocalFree`) |
| WinLocal, |
| /// Memory for args, errno, and other parts of the machine-managed environment. |
| /// This memory may leak. |
| Machine, |
| /// Memory allocated by the runtime (e.g. env vars). Separate from `Machine` |
| /// because we clean it up and leak-check it. |
| Runtime, |
| /// Globals copied from `tcx`. |
| /// This memory may leak. |
| Global, |
| /// Memory for extern statics. |
| /// This memory may leak. |
| ExternStatic, |
| /// Memory for thread-local statics. |
| /// This memory may leak. |
| Tls, |
| /// Memory mapped directly by the program |
| Mmap, |
| } |
| |
| impl From<MiriMemoryKind> for MemoryKind { |
| #[inline(always)] |
| fn from(kind: MiriMemoryKind) -> MemoryKind { |
| MemoryKind::Machine(kind) |
| } |
| } |
| |
| impl MayLeak for MiriMemoryKind { |
| #[inline(always)] |
| fn may_leak(self) -> bool { |
| use self::MiriMemoryKind::*; |
| match self { |
| Rust | Miri | C | WinHeap | WinLocal | Runtime => false, |
| Machine | Global | ExternStatic | Tls | Mmap => true, |
| } |
| } |
| } |
| |
| impl MiriMemoryKind { |
| /// Whether we have a useful allocation span for an allocation of this kind. |
| fn should_save_allocation_span(self) -> bool { |
| use self::MiriMemoryKind::*; |
| match self { |
| // Heap allocations are fine since the `Allocation` is created immediately. |
| Rust | Miri | C | WinHeap | WinLocal | Mmap => true, |
| // Everything else is unclear, let's not show potentially confusing spans. |
| Machine | Global | ExternStatic | Tls | Runtime => false, |
| } |
| } |
| } |
| |
| impl fmt::Display for MiriMemoryKind { |
| fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { |
| use self::MiriMemoryKind::*; |
| match self { |
| Rust => write!(f, "Rust heap"), |
| Miri => write!(f, "Miri bare-metal heap"), |
| C => write!(f, "C heap"), |
| WinHeap => write!(f, "Windows heap"), |
| WinLocal => write!(f, "Windows local memory"), |
| Machine => write!(f, "machine-managed memory"), |
| Runtime => write!(f, "language runtime memory"), |
| Global => write!(f, "global (static or const)"), |
| ExternStatic => write!(f, "extern static"), |
| Tls => write!(f, "thread-local static"), |
| Mmap => write!(f, "mmap"), |
| } |
| } |
| } |
| |
| pub type MemoryKind = interpret::MemoryKind<MiriMemoryKind>; |
| |
| /// Pointer provenance. |
| // This needs to be `Eq`+`Hash` because the `Machine` trait needs that because validity checking |
| // *might* be recursive and then it has to track which places have already been visited. |
| // These implementations are a bit questionable, and it means we may check the same place multiple |
| // times with different provenance, but that is in general not wrong. |
| #[derive(Clone, Copy, PartialEq, Eq, Hash)] |
| pub enum Provenance { |
| /// For pointers with concrete provenance. we exactly know which allocation they are attached to |
| /// and what their borrow tag is. |
| Concrete { |
| alloc_id: AllocId, |
| /// Borrow Tracker tag. |
| tag: BorTag, |
| }, |
| /// Pointers with wildcard provenance are created on int-to-ptr casts. According to the |
| /// specification, we should at that point angelically "guess" a provenance that will make all |
| /// future uses of this pointer work, if at all possible. Of course such a semantics cannot be |
| /// actually implemented in Miri. So instead, we approximate this, erroring on the side of |
| /// accepting too much code rather than rejecting correct code: a pointer with wildcard |
| /// provenance "acts like" any previously exposed pointer. Each time it is used, we check |
| /// whether *some* exposed pointer could have done what we want to do, and if the answer is yes |
| /// then we allow the access. This allows too much code in two ways: |
| /// - The same wildcard pointer can "take the role" of multiple different exposed pointers on |
| /// subsequent memory accesses. |
| /// - In the aliasing model, we don't just have to know the borrow tag of the pointer used for |
| /// the access, we also have to update the aliasing state -- and that update can be very |
| /// different depending on which borrow tag we pick! Stacked Borrows has support for this by |
| /// switching to a stack that is only approximately known, i.e. we over-approximate the effect |
| /// of using *any* exposed pointer for this access, and only keep information about the borrow |
| /// stack that would be true with all possible choices. |
| Wildcard, |
| } |
| |
| /// The "extra" information a pointer has over a regular AllocId. |
| #[derive(Copy, Clone, PartialEq)] |
| pub enum ProvenanceExtra { |
| Concrete(BorTag), |
| Wildcard, |
| } |
| |
| #[cfg(target_pointer_width = "64")] |
| static_assert_size!(StrictPointer, 24); |
| // FIXME: this would with in 24bytes but layout optimizations are not smart enough |
| // #[cfg(target_pointer_width = "64")] |
| //static_assert_size!(Pointer, 24); |
| #[cfg(target_pointer_width = "64")] |
| static_assert_size!(Scalar, 32); |
| |
| impl fmt::Debug for Provenance { |
| fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result { |
| match self { |
| Provenance::Concrete { alloc_id, tag } => { |
| // Forward `alternate` flag to `alloc_id` printing. |
| if f.alternate() { |
| write!(f, "[{alloc_id:#?}]")?; |
| } else { |
| write!(f, "[{alloc_id:?}]")?; |
| } |
| // Print Borrow Tracker tag. |
| write!(f, "{tag:?}")?; |
| } |
| Provenance::Wildcard => { |
| write!(f, "[wildcard]")?; |
| } |
| } |
| Ok(()) |
| } |
| } |
| |
| impl interpret::Provenance for Provenance { |
| /// We use absolute addresses in the `offset` of a `StrictPointer`. |
| const OFFSET_IS_ADDR: bool = true; |
| |
| fn get_alloc_id(self) -> Option<AllocId> { |
| match self { |
| Provenance::Concrete { alloc_id, .. } => Some(alloc_id), |
| Provenance::Wildcard => None, |
| } |
| } |
| |
| fn fmt(ptr: &interpret::Pointer<Self>, f: &mut fmt::Formatter<'_>) -> fmt::Result { |
| let (prov, addr) = ptr.into_parts(); // address is absolute |
| write!(f, "{:#x}", addr.bytes())?; |
| if f.alternate() { |
| write!(f, "{prov:#?}")?; |
| } else { |
| write!(f, "{prov:?}")?; |
| } |
| Ok(()) |
| } |
| |
| fn join(left: Option<Self>, right: Option<Self>) -> Option<Self> { |
| match (left, right) { |
| // If both are the *same* concrete tag, that is the result. |
| ( |
| Some(Provenance::Concrete { alloc_id: left_alloc, tag: left_tag }), |
| Some(Provenance::Concrete { alloc_id: right_alloc, tag: right_tag }), |
| ) if left_alloc == right_alloc && left_tag == right_tag => left, |
| // If one side is a wildcard, the best possible outcome is that it is equal to the other |
| // one, and we use that. |
| (Some(Provenance::Wildcard), o) | (o, Some(Provenance::Wildcard)) => o, |
| // Otherwise, fall back to `None`. |
| _ => None, |
| } |
| } |
| } |
| |
| impl fmt::Debug for ProvenanceExtra { |
| fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { |
| match self { |
| ProvenanceExtra::Concrete(pid) => write!(f, "{pid:?}"), |
| ProvenanceExtra::Wildcard => write!(f, "<wildcard>"), |
| } |
| } |
| } |
| |
| impl ProvenanceExtra { |
| pub fn and_then<T>(self, f: impl FnOnce(BorTag) -> Option<T>) -> Option<T> { |
| match self { |
| ProvenanceExtra::Concrete(pid) => f(pid), |
| ProvenanceExtra::Wildcard => None, |
| } |
| } |
| } |
| |
| /// Extra per-allocation data |
| #[derive(Debug)] |
| pub struct AllocExtra<'tcx> { |
| /// Global state of the borrow tracker, if enabled. |
| pub borrow_tracker: Option<borrow_tracker::AllocState>, |
| /// Data race detection via the use of a vector-clock. |
| /// This is only added if it is enabled. |
| pub data_race: Option<data_race::AllocState>, |
| /// Weak memory emulation via the use of store buffers. |
| /// This is only added if it is enabled. |
| pub weak_memory: Option<weak_memory::AllocState>, |
| /// A backtrace to where this allocation was allocated. |
| /// As this is recorded for leak reports, it only exists |
| /// if this allocation is leakable. The backtrace is not |
| /// pruned yet; that should be done before printing it. |
| pub backtrace: Option<Vec<FrameInfo<'tcx>>>, |
| /// Synchronization primitives like to attach extra data to particular addresses. We store that |
| /// inside the relevant allocation, to ensure that everything is removed when the allocation is |
| /// freed. |
| /// This maps offsets to synchronization-primitive-specific data. |
| pub sync: FxHashMap<Size, Box<dyn Any>>, |
| } |
| |
| // We need a `Clone` impl because the machine passes `Allocation` through `Cow`... |
| // but that should never end up actually cloning our `AllocExtra`. |
| impl<'tcx> Clone for AllocExtra<'tcx> { |
| fn clone(&self) -> Self { |
| panic!("our allocations should never be cloned"); |
| } |
| } |
| |
| impl VisitProvenance for AllocExtra<'_> { |
| fn visit_provenance(&self, visit: &mut VisitWith<'_>) { |
| let AllocExtra { borrow_tracker, data_race, weak_memory, backtrace: _, sync: _ } = self; |
| |
| borrow_tracker.visit_provenance(visit); |
| data_race.visit_provenance(visit); |
| weak_memory.visit_provenance(visit); |
| } |
| } |
| |
| /// Precomputed layouts of primitive types |
| pub struct PrimitiveLayouts<'tcx> { |
| pub unit: TyAndLayout<'tcx>, |
| pub i8: TyAndLayout<'tcx>, |
| pub i16: TyAndLayout<'tcx>, |
| pub i32: TyAndLayout<'tcx>, |
| pub i64: TyAndLayout<'tcx>, |
| pub i128: TyAndLayout<'tcx>, |
| pub isize: TyAndLayout<'tcx>, |
| pub u8: TyAndLayout<'tcx>, |
| pub u16: TyAndLayout<'tcx>, |
| pub u32: TyAndLayout<'tcx>, |
| pub u64: TyAndLayout<'tcx>, |
| pub u128: TyAndLayout<'tcx>, |
| pub usize: TyAndLayout<'tcx>, |
| pub bool: TyAndLayout<'tcx>, |
| pub mut_raw_ptr: TyAndLayout<'tcx>, // *mut () |
| pub const_raw_ptr: TyAndLayout<'tcx>, // *const () |
| } |
| |
| impl<'tcx> PrimitiveLayouts<'tcx> { |
| fn new(layout_cx: LayoutCx<'tcx>) -> Result<Self, &'tcx LayoutError<'tcx>> { |
| let tcx = layout_cx.tcx(); |
| let mut_raw_ptr = Ty::new_mut_ptr(tcx, tcx.types.unit); |
| let const_raw_ptr = Ty::new_imm_ptr(tcx, tcx.types.unit); |
| Ok(Self { |
| unit: layout_cx.layout_of(tcx.types.unit)?, |
| i8: layout_cx.layout_of(tcx.types.i8)?, |
| i16: layout_cx.layout_of(tcx.types.i16)?, |
| i32: layout_cx.layout_of(tcx.types.i32)?, |
| i64: layout_cx.layout_of(tcx.types.i64)?, |
| i128: layout_cx.layout_of(tcx.types.i128)?, |
| isize: layout_cx.layout_of(tcx.types.isize)?, |
| u8: layout_cx.layout_of(tcx.types.u8)?, |
| u16: layout_cx.layout_of(tcx.types.u16)?, |
| u32: layout_cx.layout_of(tcx.types.u32)?, |
| u64: layout_cx.layout_of(tcx.types.u64)?, |
| u128: layout_cx.layout_of(tcx.types.u128)?, |
| usize: layout_cx.layout_of(tcx.types.usize)?, |
| bool: layout_cx.layout_of(tcx.types.bool)?, |
| mut_raw_ptr: layout_cx.layout_of(mut_raw_ptr)?, |
| const_raw_ptr: layout_cx.layout_of(const_raw_ptr)?, |
| }) |
| } |
| |
| pub fn uint(&self, size: Size) -> Option<TyAndLayout<'tcx>> { |
| match size.bits() { |
| 8 => Some(self.u8), |
| 16 => Some(self.u16), |
| 32 => Some(self.u32), |
| 64 => Some(self.u64), |
| 128 => Some(self.u128), |
| _ => None, |
| } |
| } |
| |
| pub fn int(&self, size: Size) -> Option<TyAndLayout<'tcx>> { |
| match size.bits() { |
| 8 => Some(self.i8), |
| 16 => Some(self.i16), |
| 32 => Some(self.i32), |
| 64 => Some(self.i64), |
| 128 => Some(self.i128), |
| _ => None, |
| } |
| } |
| } |
| |
| /// The machine itself. |
| /// |
| /// If you add anything here that stores machine values, remember to update |
| /// `visit_all_machine_values`! |
| pub struct MiriMachine<'tcx> { |
| // We carry a copy of the global `TyCtxt` for convenience, so methods taking just `&Evaluator` have `tcx` access. |
| pub tcx: TyCtxt<'tcx>, |
| |
| /// Global data for borrow tracking. |
| pub borrow_tracker: Option<borrow_tracker::GlobalState>, |
| |
| /// Data race detector global data. |
| pub data_race: Option<data_race::GlobalState>, |
| |
| /// Ptr-int-cast module global data. |
| pub alloc_addresses: alloc_addresses::GlobalState, |
| |
| /// Environment variables. |
| pub(crate) env_vars: EnvVars<'tcx>, |
| |
| /// Return place of the main function. |
| pub(crate) main_fn_ret_place: Option<MPlaceTy<'tcx>>, |
| |
| /// Program arguments (`Option` because we can only initialize them after creating the ecx). |
| /// These are *pointers* to argc/argv because macOS. |
| /// We also need the full command line as one string because of Windows. |
| pub(crate) argc: Option<Pointer>, |
| pub(crate) argv: Option<Pointer>, |
| pub(crate) cmd_line: Option<Pointer>, |
| |
| /// TLS state. |
| pub(crate) tls: TlsData<'tcx>, |
| |
| /// What should Miri do when an op requires communicating with the host, |
| /// such as accessing host env vars, random number generation, and |
| /// file system access. |
| pub(crate) isolated_op: IsolatedOp, |
| |
| /// Whether to enforce the validity invariant. |
| pub(crate) validation: ValidationMode, |
| |
| /// The table of file descriptors. |
| pub(crate) fds: shims::FdTable, |
| /// The table of directory descriptors. |
| pub(crate) dirs: shims::DirTable, |
| |
| /// The list of all EpollEventInterest. |
| pub(crate) epoll_interests: shims::EpollInterestTable, |
| |
| /// This machine's monotone clock. |
| pub(crate) clock: Clock, |
| |
| /// The set of threads. |
| pub(crate) threads: ThreadManager<'tcx>, |
| |
| /// Stores which thread is eligible to run on which CPUs. |
| /// This has no effect at all, it is just tracked to produce the correct result |
| /// in `sched_getaffinity` |
| pub(crate) thread_cpu_affinity: FxHashMap<ThreadId, CpuAffinityMask>, |
| |
| /// The state of the primitive synchronization objects. |
| pub(crate) sync: SynchronizationObjects, |
| |
| /// Precomputed `TyLayout`s for primitive data types that are commonly used inside Miri. |
| pub(crate) layouts: PrimitiveLayouts<'tcx>, |
| |
| /// Allocations that are considered roots of static memory (that may leak). |
| pub(crate) static_roots: Vec<AllocId>, |
| |
| /// The `measureme` profiler used to record timing information about |
| /// the emulated program. |
| profiler: Option<measureme::Profiler>, |
| /// Used with `profiler` to cache the `StringId`s for event names |
| /// used with `measureme`. |
| string_cache: FxHashMap<String, measureme::StringId>, |
| |
| /// Cache of `Instance` exported under the given `Symbol` name. |
| /// `None` means no `Instance` exported under the given name is found. |
| pub(crate) exported_symbols_cache: FxHashMap<Symbol, Option<Instance<'tcx>>>, |
| |
| /// Equivalent setting as RUST_BACKTRACE on encountering an error. |
| pub(crate) backtrace_style: BacktraceStyle, |
| |
| /// Crates which are considered local for the purposes of error reporting. |
| pub(crate) local_crates: Vec<CrateNum>, |
| |
| /// Mapping extern static names to their pointer. |
| extern_statics: FxHashMap<Symbol, StrictPointer>, |
| |
| /// The random number generator used for resolving non-determinism. |
| /// Needs to be queried by ptr_to_int, hence needs interior mutability. |
| pub(crate) rng: RefCell<StdRng>, |
| |
| /// The allocation IDs to report when they are being allocated |
| /// (helps for debugging memory leaks and use after free bugs). |
| tracked_alloc_ids: FxHashSet<AllocId>, |
| /// For the tracked alloc ids, also report read/write accesses. |
| track_alloc_accesses: bool, |
| |
| /// Controls whether alignment of memory accesses is being checked. |
| pub(crate) check_alignment: AlignmentCheck, |
| |
| /// Failure rate of compare_exchange_weak, between 0.0 and 1.0 |
| pub(crate) cmpxchg_weak_failure_rate: f64, |
| |
| /// Corresponds to -Zmiri-mute-stdout-stderr and doesn't write the output but acts as if it succeeded. |
| pub(crate) mute_stdout_stderr: bool, |
| |
| /// Whether weak memory emulation is enabled |
| pub(crate) weak_memory: bool, |
| |
| /// The probability of the active thread being preempted at the end of each basic block. |
| pub(crate) preemption_rate: f64, |
| |
| /// If `Some`, we will report the current stack every N basic blocks. |
| pub(crate) report_progress: Option<u32>, |
| // The total number of blocks that have been executed. |
| pub(crate) basic_block_count: u64, |
| |
| /// Handle of the optional shared object file for native functions. |
| #[cfg(unix)] |
| pub native_lib: Option<(libloading::Library, std::path::PathBuf)>, |
| #[cfg(not(unix))] |
| pub native_lib: Option<!>, |
| |
| /// Run a garbage collector for BorTags every N basic blocks. |
| pub(crate) gc_interval: u32, |
| /// The number of blocks that passed since the last BorTag GC pass. |
| pub(crate) since_gc: u32, |
| |
| /// The number of CPUs to be reported by miri. |
| pub(crate) num_cpus: u32, |
| |
| /// Determines Miri's page size and associated values |
| pub(crate) page_size: u64, |
| pub(crate) stack_addr: u64, |
| pub(crate) stack_size: u64, |
| |
| /// Whether to collect a backtrace when each allocation is created, just in case it leaks. |
| pub(crate) collect_leak_backtraces: bool, |
| |
| /// The spans we will use to report where an allocation was created and deallocated in |
| /// diagnostics. |
| pub(crate) allocation_spans: RefCell<FxHashMap<AllocId, (Span, Option<Span>)>>, |
| |
| /// Maps MIR consts to their evaluated result. We combine the const with a "salt" (`usize`) |
| /// that is fixed per stack frame; this lets us have sometimes different results for the |
| /// same const while ensuring consistent results within a single call. |
| const_cache: RefCell<FxHashMap<(mir::Const<'tcx>, usize), OpTy<'tcx>>>, |
| |
| /// For each allocation, an offset inside that allocation that was deemed aligned even for |
| /// symbolic alignment checks. This cannot be stored in `AllocExtra` since it needs to be |
| /// tracked for vtables and function allocations as well as regular allocations. |
| /// |
| /// Invariant: the promised alignment will never be less than the native alignment of the |
| /// allocation. |
| pub(crate) symbolic_alignment: RefCell<FxHashMap<AllocId, (Size, Align)>>, |
| |
| /// A cache of "data range" computations for unions (i.e., the offsets of non-padding bytes). |
| union_data_ranges: FxHashMap<Ty<'tcx>, RangeSet>, |
| } |
| |
| impl<'tcx> MiriMachine<'tcx> { |
| pub(crate) fn new(config: &MiriConfig, layout_cx: LayoutCx<'tcx>) -> Self { |
| let tcx = layout_cx.tcx(); |
| let local_crates = helpers::get_local_crates(tcx); |
| let layouts = |
| PrimitiveLayouts::new(layout_cx).expect("Couldn't get layouts of primitive types"); |
| let profiler = config.measureme_out.as_ref().map(|out| { |
| let crate_name = |
| tcx.sess.opts.crate_name.clone().unwrap_or_else(|| "unknown-crate".to_string()); |
| let pid = process::id(); |
| // We adopt the same naming scheme for the profiler output that rustc uses. In rustc, |
| // the PID is padded so that the nondeterministic value of the PID does not spread |
| // nondeterminism to the allocator. In Miri we are not aiming for such performance |
| // control, we just pad for consistency with rustc. |
| let filename = format!("{crate_name}-{pid:07}"); |
| let path = Path::new(out).join(filename); |
| measureme::Profiler::new(path).expect("Couldn't create `measureme` profiler") |
| }); |
| let rng = StdRng::seed_from_u64(config.seed.unwrap_or(0)); |
| let borrow_tracker = config.borrow_tracker.map(|bt| bt.instantiate_global_state(config)); |
| let data_race = config.data_race_detector.then(|| data_race::GlobalState::new(config)); |
| // Determine page size, stack address, and stack size. |
| // These values are mostly meaningless, but the stack address is also where we start |
| // allocating physical integer addresses for all allocations. |
| let page_size = if let Some(page_size) = config.page_size { |
| page_size |
| } else { |
| let target = &tcx.sess.target; |
| match target.arch.as_ref() { |
| "wasm32" | "wasm64" => 64 * 1024, // https://webassembly.github.io/spec/core/exec/runtime.html#memory-instances |
| "aarch64" => { |
| if target.options.vendor.as_ref() == "apple" { |
| // No "definitive" source, but see: |
| // https://www.wwdcnotes.com/notes/wwdc20/10214/ |
| // https://github.com/ziglang/zig/issues/11308 etc. |
| 16 * 1024 |
| } else { |
| 4 * 1024 |
| } |
| } |
| _ => 4 * 1024, |
| } |
| }; |
| // On 16bit targets, 32 pages is more than the entire address space! |
| let stack_addr = if tcx.pointer_size().bits() < 32 { page_size } else { page_size * 32 }; |
| let stack_size = |
| if tcx.pointer_size().bits() < 32 { page_size * 4 } else { page_size * 16 }; |
| assert!( |
| usize::try_from(config.num_cpus).unwrap() <= cpu_affinity::MAX_CPUS, |
| "miri only supports up to {} CPUs, but {} were configured", |
| cpu_affinity::MAX_CPUS, |
| config.num_cpus |
| ); |
| let threads = ThreadManager::default(); |
| let mut thread_cpu_affinity = FxHashMap::default(); |
| if matches!(&*tcx.sess.target.os, "linux" | "freebsd" | "android") { |
| thread_cpu_affinity |
| .insert(threads.active_thread(), CpuAffinityMask::new(&layout_cx, config.num_cpus)); |
| } |
| MiriMachine { |
| tcx, |
| borrow_tracker, |
| data_race, |
| alloc_addresses: RefCell::new(alloc_addresses::GlobalStateInner::new(config, stack_addr)), |
| // `env_vars` depends on a full interpreter so we cannot properly initialize it yet. |
| env_vars: EnvVars::default(), |
| main_fn_ret_place: None, |
| argc: None, |
| argv: None, |
| cmd_line: None, |
| tls: TlsData::default(), |
| isolated_op: config.isolated_op, |
| validation: config.validation, |
| fds: shims::FdTable::init(config.mute_stdout_stderr), |
| epoll_interests: shims::EpollInterestTable::new(), |
| dirs: Default::default(), |
| layouts, |
| threads, |
| thread_cpu_affinity, |
| sync: SynchronizationObjects::default(), |
| static_roots: Vec::new(), |
| profiler, |
| string_cache: Default::default(), |
| exported_symbols_cache: FxHashMap::default(), |
| backtrace_style: config.backtrace_style, |
| local_crates, |
| extern_statics: FxHashMap::default(), |
| rng: RefCell::new(rng), |
| tracked_alloc_ids: config.tracked_alloc_ids.clone(), |
| track_alloc_accesses: config.track_alloc_accesses, |
| check_alignment: config.check_alignment, |
| cmpxchg_weak_failure_rate: config.cmpxchg_weak_failure_rate, |
| mute_stdout_stderr: config.mute_stdout_stderr, |
| weak_memory: config.weak_memory_emulation, |
| preemption_rate: config.preemption_rate, |
| report_progress: config.report_progress, |
| basic_block_count: 0, |
| clock: Clock::new(config.isolated_op == IsolatedOp::Allow), |
| #[cfg(unix)] |
| native_lib: config.native_lib.as_ref().map(|lib_file_path| { |
| let target_triple = tcx.sess.opts.target_triple.tuple(); |
| // Check if host target == the session target. |
| if env!("TARGET") != target_triple { |
| panic!( |
| "calling external C functions in linked .so file requires host and target to be the same: host={}, target={}", |
| env!("TARGET"), |
| target_triple, |
| ); |
| } |
| // Note: it is the user's responsibility to provide a correct SO file. |
| // WATCH OUT: If an invalid/incorrect SO file is specified, this can cause |
| // undefined behaviour in Miri itself! |
| ( |
| unsafe { |
| libloading::Library::new(lib_file_path) |
| .expect("failed to read specified extern shared object file") |
| }, |
| lib_file_path.clone(), |
| ) |
| }), |
| #[cfg(not(unix))] |
| native_lib: config.native_lib.as_ref().map(|_| { |
| panic!("calling functions from native libraries via FFI is only supported on Unix") |
| }), |
| gc_interval: config.gc_interval, |
| since_gc: 0, |
| num_cpus: config.num_cpus, |
| page_size, |
| stack_addr, |
| stack_size, |
| collect_leak_backtraces: config.collect_leak_backtraces, |
| allocation_spans: RefCell::new(FxHashMap::default()), |
| const_cache: RefCell::new(FxHashMap::default()), |
| symbolic_alignment: RefCell::new(FxHashMap::default()), |
| union_data_ranges: FxHashMap::default(), |
| } |
| } |
| |
| pub(crate) fn late_init( |
| this: &mut MiriInterpCx<'tcx>, |
| config: &MiriConfig, |
| on_main_stack_empty: StackEmptyCallback<'tcx>, |
| ) -> InterpResult<'tcx> { |
| EnvVars::init(this, config)?; |
| MiriMachine::init_extern_statics(this)?; |
| ThreadManager::init(this, on_main_stack_empty); |
| interp_ok(()) |
| } |
| |
| pub(crate) fn add_extern_static(this: &mut MiriInterpCx<'tcx>, name: &str, ptr: Pointer) { |
| // This got just allocated, so there definitely is a pointer here. |
| let ptr = ptr.into_pointer_or_addr().unwrap(); |
| this.machine.extern_statics.try_insert(Symbol::intern(name), ptr).unwrap(); |
| } |
| |
| pub(crate) fn communicate(&self) -> bool { |
| self.isolated_op == IsolatedOp::Allow |
| } |
| |
| /// Check whether the stack frame that this `FrameInfo` refers to is part of a local crate. |
| pub(crate) fn is_local(&self, frame: &FrameInfo<'_>) -> bool { |
| let def_id = frame.instance.def_id(); |
| def_id.is_local() || self.local_crates.contains(&def_id.krate) |
| } |
| |
| /// Called when the interpreter is going to shut down abnormally, such as due to a Ctrl-C. |
| pub(crate) fn handle_abnormal_termination(&mut self) { |
| // All strings in the profile data are stored in a single string table which is not |
| // written to disk until the profiler is dropped. If the interpreter exits without dropping |
| // the profiler, it is not possible to interpret the profile data and all measureme tools |
| // will panic when given the file. |
| drop(self.profiler.take()); |
| } |
| |
| pub(crate) fn page_align(&self) -> Align { |
| Align::from_bytes(self.page_size).unwrap() |
| } |
| |
| pub(crate) fn allocated_span(&self, alloc_id: AllocId) -> Option<SpanData> { |
| self.allocation_spans |
| .borrow() |
| .get(&alloc_id) |
| .map(|(allocated, _deallocated)| allocated.data()) |
| } |
| |
| pub(crate) fn deallocated_span(&self, alloc_id: AllocId) -> Option<SpanData> { |
| self.allocation_spans |
| .borrow() |
| .get(&alloc_id) |
| .and_then(|(_allocated, deallocated)| *deallocated) |
| .map(Span::data) |
| } |
| } |
| |
| impl VisitProvenance for MiriMachine<'_> { |
| fn visit_provenance(&self, visit: &mut VisitWith<'_>) { |
| #[rustfmt::skip] |
| let MiriMachine { |
| threads, |
| thread_cpu_affinity: _, |
| sync: _, |
| tls, |
| env_vars, |
| main_fn_ret_place, |
| argc, |
| argv, |
| cmd_line, |
| extern_statics, |
| dirs, |
| borrow_tracker, |
| data_race, |
| alloc_addresses, |
| fds, |
| epoll_interests:_, |
| tcx: _, |
| isolated_op: _, |
| validation: _, |
| clock: _, |
| layouts: _, |
| static_roots: _, |
| profiler: _, |
| string_cache: _, |
| exported_symbols_cache: _, |
| backtrace_style: _, |
| local_crates: _, |
| rng: _, |
| tracked_alloc_ids: _, |
| track_alloc_accesses: _, |
| check_alignment: _, |
| cmpxchg_weak_failure_rate: _, |
| mute_stdout_stderr: _, |
| weak_memory: _, |
| preemption_rate: _, |
| report_progress: _, |
| basic_block_count: _, |
| native_lib: _, |
| gc_interval: _, |
| since_gc: _, |
| num_cpus: _, |
| page_size: _, |
| stack_addr: _, |
| stack_size: _, |
| collect_leak_backtraces: _, |
| allocation_spans: _, |
| const_cache: _, |
| symbolic_alignment: _, |
| union_data_ranges: _, |
| } = self; |
| |
| threads.visit_provenance(visit); |
| tls.visit_provenance(visit); |
| env_vars.visit_provenance(visit); |
| dirs.visit_provenance(visit); |
| fds.visit_provenance(visit); |
| data_race.visit_provenance(visit); |
| borrow_tracker.visit_provenance(visit); |
| alloc_addresses.visit_provenance(visit); |
| main_fn_ret_place.visit_provenance(visit); |
| argc.visit_provenance(visit); |
| argv.visit_provenance(visit); |
| cmd_line.visit_provenance(visit); |
| for ptr in extern_statics.values() { |
| ptr.visit_provenance(visit); |
| } |
| } |
| } |
| |
| /// A rustc InterpCx for Miri. |
| pub type MiriInterpCx<'tcx> = InterpCx<'tcx, MiriMachine<'tcx>>; |
| |
| /// A little trait that's useful to be inherited by extension traits. |
| pub trait MiriInterpCxExt<'tcx> { |
| fn eval_context_ref<'a>(&'a self) -> &'a MiriInterpCx<'tcx>; |
| fn eval_context_mut<'a>(&'a mut self) -> &'a mut MiriInterpCx<'tcx>; |
| } |
| impl<'tcx> MiriInterpCxExt<'tcx> for MiriInterpCx<'tcx> { |
| #[inline(always)] |
| fn eval_context_ref(&self) -> &MiriInterpCx<'tcx> { |
| self |
| } |
| #[inline(always)] |
| fn eval_context_mut(&mut self) -> &mut MiriInterpCx<'tcx> { |
| self |
| } |
| } |
| |
| /// Machine hook implementations. |
| impl<'tcx> Machine<'tcx> for MiriMachine<'tcx> { |
| type MemoryKind = MiriMemoryKind; |
| type ExtraFnVal = DynSym; |
| |
| type FrameExtra = FrameExtra<'tcx>; |
| type AllocExtra = AllocExtra<'tcx>; |
| |
| type Provenance = Provenance; |
| type ProvenanceExtra = ProvenanceExtra; |
| type Bytes = MiriAllocBytes; |
| |
| type MemoryMap = |
| MonoHashMap<AllocId, (MemoryKind, Allocation<Provenance, Self::AllocExtra, Self::Bytes>)>; |
| |
| const GLOBAL_KIND: Option<MiriMemoryKind> = Some(MiriMemoryKind::Global); |
| |
| const PANIC_ON_ALLOC_FAIL: bool = false; |
| |
| #[inline(always)] |
| fn enforce_alignment(ecx: &MiriInterpCx<'tcx>) -> bool { |
| ecx.machine.check_alignment != AlignmentCheck::None |
| } |
| |
| #[inline(always)] |
| fn alignment_check( |
| ecx: &MiriInterpCx<'tcx>, |
| alloc_id: AllocId, |
| alloc_align: Align, |
| alloc_kind: AllocKind, |
| offset: Size, |
| align: Align, |
| ) -> Option<Misalignment> { |
| if ecx.machine.check_alignment != AlignmentCheck::Symbolic { |
| // Just use the built-in check. |
| return None; |
| } |
| if alloc_kind != AllocKind::LiveData { |
| // Can't have any extra info here. |
| return None; |
| } |
| // Let's see which alignment we have been promised for this allocation. |
| let (promised_offset, promised_align) = ecx |
| .machine |
| .symbolic_alignment |
| .borrow() |
| .get(&alloc_id) |
| .copied() |
| .unwrap_or((Size::ZERO, alloc_align)); |
| if promised_align < align { |
| // Definitely not enough. |
| Some(Misalignment { has: promised_align, required: align }) |
| } else { |
| // What's the offset between us and the promised alignment? |
| let distance = offset.bytes().wrapping_sub(promised_offset.bytes()); |
| // That must also be aligned. |
| if distance % align.bytes() == 0 { |
| // All looking good! |
| None |
| } else { |
| // The biggest power of two through which `distance` is divisible. |
| let distance_pow2 = 1 << distance.trailing_zeros(); |
| Some(Misalignment { |
| has: Align::from_bytes(distance_pow2).unwrap(), |
| required: align, |
| }) |
| } |
| } |
| } |
| |
| #[inline(always)] |
| fn enforce_validity(ecx: &MiriInterpCx<'tcx>, _layout: TyAndLayout<'tcx>) -> bool { |
| ecx.machine.validation != ValidationMode::No |
| } |
| #[inline(always)] |
| fn enforce_validity_recursively( |
| ecx: &InterpCx<'tcx, Self>, |
| _layout: TyAndLayout<'tcx>, |
| ) -> bool { |
| ecx.machine.validation == ValidationMode::Deep |
| } |
| |
| #[inline(always)] |
| fn ignore_optional_overflow_checks(ecx: &MiriInterpCx<'tcx>) -> bool { |
| !ecx.tcx.sess.overflow_checks() |
| } |
| |
| fn check_fn_target_features( |
| ecx: &MiriInterpCx<'tcx>, |
| instance: ty::Instance<'tcx>, |
| ) -> InterpResult<'tcx> { |
| let attrs = ecx.tcx.codegen_fn_attrs(instance.def_id()); |
| if attrs |
| .target_features |
| .iter() |
| .any(|feature| !ecx.tcx.sess.target_features.contains(&feature.name)) |
| { |
| let unavailable = attrs |
| .target_features |
| .iter() |
| .filter(|&feature| { |
| !feature.implied && !ecx.tcx.sess.target_features.contains(&feature.name) |
| }) |
| .fold(String::new(), |mut s, feature| { |
| if !s.is_empty() { |
| s.push_str(", "); |
| } |
| s.push_str(feature.name.as_str()); |
| s |
| }); |
| let msg = format!( |
| "calling a function that requires unavailable target features: {unavailable}" |
| ); |
| // On WASM, this is not UB, but instead gets rejected during validation of the module |
| // (see #84988). |
| if ecx.tcx.sess.target.is_like_wasm { |
| throw_machine_stop!(TerminationInfo::Abort(msg)); |
| } else { |
| throw_ub_format!("{msg}"); |
| } |
| } |
| interp_ok(()) |
| } |
| |
| #[inline(always)] |
| fn find_mir_or_eval_fn( |
| ecx: &mut MiriInterpCx<'tcx>, |
| instance: ty::Instance<'tcx>, |
| abi: ExternAbi, |
| args: &[FnArg<'tcx, Provenance>], |
| dest: &MPlaceTy<'tcx>, |
| ret: Option<mir::BasicBlock>, |
| unwind: mir::UnwindAction, |
| ) -> InterpResult<'tcx, Option<(&'tcx mir::Body<'tcx>, ty::Instance<'tcx>)>> { |
| // For foreign items, try to see if we can emulate them. |
| if ecx.tcx.is_foreign_item(instance.def_id()) { |
| // An external function call that does not have a MIR body. We either find MIR elsewhere |
| // or emulate its effect. |
| // This will be Ok(None) if we're emulating the intrinsic entirely within Miri (no need |
| // to run extra MIR), and Ok(Some(body)) if we found MIR to run for the |
| // foreign function |
| // Any needed call to `goto_block` will be performed by `emulate_foreign_item`. |
| let args = ecx.copy_fn_args(args); // FIXME: Should `InPlace` arguments be reset to uninit? |
| let link_name = Symbol::intern(ecx.tcx.symbol_name(instance).name); |
| return ecx.emulate_foreign_item(link_name, abi, &args, dest, ret, unwind); |
| } |
| |
| // Otherwise, load the MIR. |
| interp_ok(Some((ecx.load_mir(instance.def, None)?, instance))) |
| } |
| |
| #[inline(always)] |
| fn call_extra_fn( |
| ecx: &mut MiriInterpCx<'tcx>, |
| fn_val: DynSym, |
| abi: ExternAbi, |
| args: &[FnArg<'tcx, Provenance>], |
| dest: &MPlaceTy<'tcx>, |
| ret: Option<mir::BasicBlock>, |
| unwind: mir::UnwindAction, |
| ) -> InterpResult<'tcx> { |
| let args = ecx.copy_fn_args(args); // FIXME: Should `InPlace` arguments be reset to uninit? |
| ecx.emulate_dyn_sym(fn_val, abi, &args, dest, ret, unwind) |
| } |
| |
| #[inline(always)] |
| fn call_intrinsic( |
| ecx: &mut MiriInterpCx<'tcx>, |
| instance: ty::Instance<'tcx>, |
| args: &[OpTy<'tcx>], |
| dest: &MPlaceTy<'tcx>, |
| ret: Option<mir::BasicBlock>, |
| unwind: mir::UnwindAction, |
| ) -> InterpResult<'tcx, Option<ty::Instance<'tcx>>> { |
| ecx.call_intrinsic(instance, args, dest, ret, unwind) |
| } |
| |
| #[inline(always)] |
| fn assert_panic( |
| ecx: &mut MiriInterpCx<'tcx>, |
| msg: &mir::AssertMessage<'tcx>, |
| unwind: mir::UnwindAction, |
| ) -> InterpResult<'tcx> { |
| ecx.assert_panic(msg, unwind) |
| } |
| |
| fn panic_nounwind(ecx: &mut InterpCx<'tcx, Self>, msg: &str) -> InterpResult<'tcx> { |
| ecx.start_panic_nounwind(msg) |
| } |
| |
| fn unwind_terminate( |
| ecx: &mut InterpCx<'tcx, Self>, |
| reason: mir::UnwindTerminateReason, |
| ) -> InterpResult<'tcx> { |
| // Call the lang item. |
| let panic = ecx.tcx.lang_items().get(reason.lang_item()).unwrap(); |
| let panic = ty::Instance::mono(ecx.tcx.tcx, panic); |
| ecx.call_function(panic, ExternAbi::Rust, &[], None, StackPopCleanup::Goto { |
| ret: None, |
| unwind: mir::UnwindAction::Unreachable, |
| })?; |
| interp_ok(()) |
| } |
| |
| #[inline(always)] |
| fn binary_ptr_op( |
| ecx: &MiriInterpCx<'tcx>, |
| bin_op: mir::BinOp, |
| left: &ImmTy<'tcx>, |
| right: &ImmTy<'tcx>, |
| ) -> InterpResult<'tcx, ImmTy<'tcx>> { |
| ecx.binary_ptr_op(bin_op, left, right) |
| } |
| |
| #[inline(always)] |
| fn generate_nan< |
| F1: rustc_apfloat::Float + rustc_apfloat::FloatConvert<F2>, |
| F2: rustc_apfloat::Float, |
| >( |
| ecx: &InterpCx<'tcx, Self>, |
| inputs: &[F1], |
| ) -> F2 { |
| ecx.generate_nan(inputs) |
| } |
| |
| fn ub_checks(ecx: &InterpCx<'tcx, Self>) -> InterpResult<'tcx, bool> { |
| interp_ok(ecx.tcx.sess.ub_checks()) |
| } |
| |
| fn thread_local_static_pointer( |
| ecx: &mut MiriInterpCx<'tcx>, |
| def_id: DefId, |
| ) -> InterpResult<'tcx, StrictPointer> { |
| ecx.get_or_create_thread_local_alloc(def_id) |
| } |
| |
| fn extern_static_pointer( |
| ecx: &MiriInterpCx<'tcx>, |
| def_id: DefId, |
| ) -> InterpResult<'tcx, StrictPointer> { |
| let link_name = Symbol::intern(ecx.tcx.symbol_name(Instance::mono(*ecx.tcx, def_id)).name); |
| if let Some(&ptr) = ecx.machine.extern_statics.get(&link_name) { |
| // Various parts of the engine rely on `get_alloc_info` for size and alignment |
| // information. That uses the type information of this static. |
| // Make sure it matches the Miri allocation for this. |
| let Provenance::Concrete { alloc_id, .. } = ptr.provenance else { |
| panic!("extern_statics cannot contain wildcards") |
| }; |
| let (shim_size, shim_align, _kind) = ecx.get_alloc_info(alloc_id); |
| let def_ty = ecx.tcx.type_of(def_id).instantiate_identity(); |
| let extern_decl_layout = ecx.tcx.layout_of(ty::ParamEnv::empty().and(def_ty)).unwrap(); |
| if extern_decl_layout.size != shim_size || extern_decl_layout.align.abi != shim_align { |
| throw_unsup_format!( |
| "extern static `{link_name}` has been declared as `{krate}::{name}` \ |
| with a size of {decl_size} bytes and alignment of {decl_align} bytes, \ |
| but Miri emulates it via an extern static shim \ |
| with a size of {shim_size} bytes and alignment of {shim_align} bytes", |
| name = ecx.tcx.def_path_str(def_id), |
| krate = ecx.tcx.crate_name(def_id.krate), |
| decl_size = extern_decl_layout.size.bytes(), |
| decl_align = extern_decl_layout.align.abi.bytes(), |
| shim_size = shim_size.bytes(), |
| shim_align = shim_align.bytes(), |
| ) |
| } |
| interp_ok(ptr) |
| } else { |
| throw_unsup_format!("extern static `{link_name}` is not supported by Miri",) |
| } |
| } |
| |
| fn init_alloc_extra( |
| ecx: &MiriInterpCx<'tcx>, |
| id: AllocId, |
| kind: MemoryKind, |
| size: Size, |
| align: Align, |
| ) -> InterpResult<'tcx, Self::AllocExtra> { |
| if ecx.machine.tracked_alloc_ids.contains(&id) { |
| ecx.emit_diagnostic(NonHaltingDiagnostic::CreatedAlloc(id, size, align, kind)); |
| } |
| |
| let borrow_tracker = ecx |
| .machine |
| .borrow_tracker |
| .as_ref() |
| .map(|bt| bt.borrow_mut().new_allocation(id, size, kind, &ecx.machine)); |
| |
| let data_race = ecx.machine.data_race.as_ref().map(|data_race| { |
| data_race::AllocState::new_allocation( |
| data_race, |
| &ecx.machine.threads, |
| size, |
| kind, |
| ecx.machine.current_span(), |
| ) |
| }); |
| let weak_memory = ecx.machine.weak_memory.then(weak_memory::AllocState::new_allocation); |
| |
| // If an allocation is leaked, we want to report a backtrace to indicate where it was |
| // allocated. We don't need to record a backtrace for allocations which are allowed to |
| // leak. |
| let backtrace = if kind.may_leak() || !ecx.machine.collect_leak_backtraces { |
| None |
| } else { |
| Some(ecx.generate_stacktrace()) |
| }; |
| |
| if matches!(kind, MemoryKind::Machine(kind) if kind.should_save_allocation_span()) { |
| ecx.machine |
| .allocation_spans |
| .borrow_mut() |
| .insert(id, (ecx.machine.current_span(), None)); |
| } |
| |
| interp_ok(AllocExtra { |
| borrow_tracker, |
| data_race, |
| weak_memory, |
| backtrace, |
| sync: FxHashMap::default(), |
| }) |
| } |
| |
| fn adjust_alloc_root_pointer( |
| ecx: &MiriInterpCx<'tcx>, |
| ptr: interpret::Pointer<CtfeProvenance>, |
| kind: Option<MemoryKind>, |
| ) -> InterpResult<'tcx, interpret::Pointer<Provenance>> { |
| let kind = kind.expect("we set our GLOBAL_KIND so this cannot be None"); |
| let alloc_id = ptr.provenance.alloc_id(); |
| if cfg!(debug_assertions) { |
| // The machine promises to never call us on thread-local or extern statics. |
| match ecx.tcx.try_get_global_alloc(alloc_id) { |
| Some(GlobalAlloc::Static(def_id)) if ecx.tcx.is_thread_local_static(def_id) => { |
| panic!("adjust_alloc_root_pointer called on thread-local static") |
| } |
| Some(GlobalAlloc::Static(def_id)) if ecx.tcx.is_foreign_item(def_id) => { |
| panic!("adjust_alloc_root_pointer called on extern static") |
| } |
| _ => {} |
| } |
| } |
| // FIXME: can we somehow preserve the immutability of `ptr`? |
| let tag = if let Some(borrow_tracker) = &ecx.machine.borrow_tracker { |
| borrow_tracker.borrow_mut().root_ptr_tag(alloc_id, &ecx.machine) |
| } else { |
| // Value does not matter, SB is disabled |
| BorTag::default() |
| }; |
| ecx.adjust_alloc_root_pointer(ptr, tag, kind) |
| } |
| |
| /// Called on `usize as ptr` casts. |
| #[inline(always)] |
| fn ptr_from_addr_cast(ecx: &MiriInterpCx<'tcx>, addr: u64) -> InterpResult<'tcx, Pointer> { |
| ecx.ptr_from_addr_cast(addr) |
| } |
| |
| /// Called on `ptr as usize` casts. |
| /// (Actually computing the resulting `usize` doesn't need machine help, |
| /// that's just `Scalar::try_to_int`.) |
| fn expose_ptr(ecx: &mut InterpCx<'tcx, Self>, ptr: StrictPointer) -> InterpResult<'tcx> { |
| match ptr.provenance { |
| Provenance::Concrete { alloc_id, tag } => ecx.expose_ptr(alloc_id, tag), |
| Provenance::Wildcard => { |
| // No need to do anything for wildcard pointers as |
| // their provenances have already been previously exposed. |
| interp_ok(()) |
| } |
| } |
| } |
| |
| /// Convert a pointer with provenance into an allocation-offset pair and extra provenance info. |
| /// `size` says how many bytes of memory are expected at that pointer. The *sign* of `size` can |
| /// be used to disambiguate situations where a wildcard pointer sits right in between two |
| /// allocations. |
| /// |
| /// If `ptr.provenance.get_alloc_id()` is `Some(p)`, the returned `AllocId` must be `p`. |
| /// The resulting `AllocId` will just be used for that one step and the forgotten again |
| /// (i.e., we'll never turn the data returned here back into a `Pointer` that might be |
| /// stored in machine state). |
| /// |
| /// When this fails, that means the pointer does not point to a live allocation. |
| fn ptr_get_alloc( |
| ecx: &MiriInterpCx<'tcx>, |
| ptr: StrictPointer, |
| size: i64, |
| ) -> Option<(AllocId, Size, Self::ProvenanceExtra)> { |
| let rel = ecx.ptr_get_alloc(ptr, size); |
| |
| rel.map(|(alloc_id, size)| { |
| let tag = match ptr.provenance { |
| Provenance::Concrete { tag, .. } => ProvenanceExtra::Concrete(tag), |
| Provenance::Wildcard => ProvenanceExtra::Wildcard, |
| }; |
| (alloc_id, size, tag) |
| }) |
| } |
| |
| /// Called to adjust global allocations to the Provenance and AllocExtra of this machine. |
| /// |
| /// If `alloc` contains pointers, then they are all pointing to globals. |
| /// |
| /// This should avoid copying if no work has to be done! If this returns an owned |
| /// allocation (because a copy had to be done to adjust things), machine memory will |
| /// cache the result. (This relies on `AllocMap::get_or` being able to add the |
| /// owned allocation to the map even when the map is shared.) |
| fn adjust_global_allocation<'b>( |
| ecx: &InterpCx<'tcx, Self>, |
| id: AllocId, |
| alloc: &'b Allocation, |
| ) -> InterpResult<'tcx, Cow<'b, Allocation<Self::Provenance, Self::AllocExtra, Self::Bytes>>> |
| { |
| let kind = Self::GLOBAL_KIND.unwrap().into(); |
| let alloc = alloc.adjust_from_tcx( |
| &ecx.tcx, |
| |bytes, align| ecx.get_global_alloc_bytes(id, kind, bytes, align), |
| |ptr| ecx.global_root_pointer(ptr), |
| )?; |
| let extra = Self::init_alloc_extra(ecx, id, kind, alloc.size(), alloc.align)?; |
| interp_ok(Cow::Owned(alloc.with_extra(extra))) |
| } |
| |
| #[inline(always)] |
| fn before_memory_read( |
| _tcx: TyCtxtAt<'tcx>, |
| machine: &Self, |
| alloc_extra: &AllocExtra<'tcx>, |
| (alloc_id, prov_extra): (AllocId, Self::ProvenanceExtra), |
| range: AllocRange, |
| ) -> InterpResult<'tcx> { |
| if machine.track_alloc_accesses && machine.tracked_alloc_ids.contains(&alloc_id) { |
| machine |
| .emit_diagnostic(NonHaltingDiagnostic::AccessedAlloc(alloc_id, AccessKind::Read)); |
| } |
| if let Some(data_race) = &alloc_extra.data_race { |
| data_race.read(alloc_id, range, NaReadType::Read, None, machine)?; |
| } |
| if let Some(borrow_tracker) = &alloc_extra.borrow_tracker { |
| borrow_tracker.before_memory_read(alloc_id, prov_extra, range, machine)?; |
| } |
| if let Some(weak_memory) = &alloc_extra.weak_memory { |
| weak_memory.memory_accessed(range, machine.data_race.as_ref().unwrap()); |
| } |
| interp_ok(()) |
| } |
| |
| #[inline(always)] |
| fn before_memory_write( |
| _tcx: TyCtxtAt<'tcx>, |
| machine: &mut Self, |
| alloc_extra: &mut AllocExtra<'tcx>, |
| (alloc_id, prov_extra): (AllocId, Self::ProvenanceExtra), |
| range: AllocRange, |
| ) -> InterpResult<'tcx> { |
| if machine.track_alloc_accesses && machine.tracked_alloc_ids.contains(&alloc_id) { |
| machine |
| .emit_diagnostic(NonHaltingDiagnostic::AccessedAlloc(alloc_id, AccessKind::Write)); |
| } |
| if let Some(data_race) = &mut alloc_extra.data_race { |
| data_race.write(alloc_id, range, NaWriteType::Write, None, machine)?; |
| } |
| if let Some(borrow_tracker) = &mut alloc_extra.borrow_tracker { |
| borrow_tracker.before_memory_write(alloc_id, prov_extra, range, machine)?; |
| } |
| if let Some(weak_memory) = &alloc_extra.weak_memory { |
| weak_memory.memory_accessed(range, machine.data_race.as_ref().unwrap()); |
| } |
| interp_ok(()) |
| } |
| |
| #[inline(always)] |
| fn before_memory_deallocation( |
| _tcx: TyCtxtAt<'tcx>, |
| machine: &mut Self, |
| alloc_extra: &mut AllocExtra<'tcx>, |
| (alloc_id, prove_extra): (AllocId, Self::ProvenanceExtra), |
| size: Size, |
| align: Align, |
| kind: MemoryKind, |
| ) -> InterpResult<'tcx> { |
| if machine.tracked_alloc_ids.contains(&alloc_id) { |
| machine.emit_diagnostic(NonHaltingDiagnostic::FreedAlloc(alloc_id)); |
| } |
| if let Some(data_race) = &mut alloc_extra.data_race { |
| data_race.write( |
| alloc_id, |
| alloc_range(Size::ZERO, size), |
| NaWriteType::Deallocate, |
| None, |
| machine, |
| )?; |
| } |
| if let Some(borrow_tracker) = &mut alloc_extra.borrow_tracker { |
| borrow_tracker.before_memory_deallocation(alloc_id, prove_extra, size, machine)?; |
| } |
| if let Some((_, deallocated_at)) = machine.allocation_spans.borrow_mut().get_mut(&alloc_id) |
| { |
| *deallocated_at = Some(machine.current_span()); |
| } |
| machine.free_alloc_id(alloc_id, size, align, kind); |
| interp_ok(()) |
| } |
| |
| #[inline(always)] |
| fn retag_ptr_value( |
| ecx: &mut InterpCx<'tcx, Self>, |
| kind: mir::RetagKind, |
| val: &ImmTy<'tcx>, |
| ) -> InterpResult<'tcx, ImmTy<'tcx>> { |
| if ecx.machine.borrow_tracker.is_some() { |
| ecx.retag_ptr_value(kind, val) |
| } else { |
| interp_ok(val.clone()) |
| } |
| } |
| |
| #[inline(always)] |
| fn retag_place_contents( |
| ecx: &mut InterpCx<'tcx, Self>, |
| kind: mir::RetagKind, |
| place: &PlaceTy<'tcx>, |
| ) -> InterpResult<'tcx> { |
| if ecx.machine.borrow_tracker.is_some() { |
| ecx.retag_place_contents(kind, place)?; |
| } |
| interp_ok(()) |
| } |
| |
| fn protect_in_place_function_argument( |
| ecx: &mut InterpCx<'tcx, Self>, |
| place: &MPlaceTy<'tcx>, |
| ) -> InterpResult<'tcx> { |
| // If we have a borrow tracker, we also have it set up protection so that all reads *and |
| // writes* during this call are insta-UB. |
| let protected_place = if ecx.machine.borrow_tracker.is_some() { |
| ecx.protect_place(place)? |
| } else { |
| // No borrow tracker. |
| place.clone() |
| }; |
| // We do need to write `uninit` so that even after the call ends, the former contents of |
| // this place cannot be observed any more. We do the write after retagging so that for |
| // Tree Borrows, this is considered to activate the new tag. |
| // Conveniently this also ensures that the place actually points to suitable memory. |
| ecx.write_uninit(&protected_place)?; |
| // Now we throw away the protected place, ensuring its tag is never used again. |
| interp_ok(()) |
| } |
| |
| #[inline(always)] |
| fn init_frame( |
| ecx: &mut InterpCx<'tcx, Self>, |
| frame: Frame<'tcx, Provenance>, |
| ) -> InterpResult<'tcx, Frame<'tcx, Provenance, FrameExtra<'tcx>>> { |
| // Start recording our event before doing anything else |
| let timing = if let Some(profiler) = ecx.machine.profiler.as_ref() { |
| let fn_name = frame.instance().to_string(); |
| let entry = ecx.machine.string_cache.entry(fn_name.clone()); |
| let name = entry.or_insert_with(|| profiler.alloc_string(&*fn_name)); |
| |
| Some(profiler.start_recording_interval_event_detached( |
| *name, |
| measureme::EventId::from_label(*name), |
| ecx.active_thread().to_u32(), |
| )) |
| } else { |
| None |
| }; |
| |
| let borrow_tracker = ecx.machine.borrow_tracker.as_ref(); |
| |
| let extra = FrameExtra { |
| borrow_tracker: borrow_tracker.map(|bt| bt.borrow_mut().new_frame()), |
| catch_unwind: None, |
| timing, |
| is_user_relevant: ecx.machine.is_user_relevant(&frame), |
| salt: ecx.machine.rng.borrow_mut().gen::<usize>() % ADDRS_PER_ANON_GLOBAL, |
| data_race: ecx.machine.data_race.as_ref().map(|_| data_race::FrameState::default()), |
| }; |
| |
| interp_ok(frame.with_extra(extra)) |
| } |
| |
| fn stack<'a>( |
| ecx: &'a InterpCx<'tcx, Self>, |
| ) -> &'a [Frame<'tcx, Self::Provenance, Self::FrameExtra>] { |
| ecx.active_thread_stack() |
| } |
| |
| fn stack_mut<'a>( |
| ecx: &'a mut InterpCx<'tcx, Self>, |
| ) -> &'a mut Vec<Frame<'tcx, Self::Provenance, Self::FrameExtra>> { |
| ecx.active_thread_stack_mut() |
| } |
| |
| fn before_terminator(ecx: &mut InterpCx<'tcx, Self>) -> InterpResult<'tcx> { |
| ecx.machine.basic_block_count += 1u64; // a u64 that is only incremented by 1 will "never" overflow |
| ecx.machine.since_gc += 1; |
| // Possibly report our progress. |
| if let Some(report_progress) = ecx.machine.report_progress { |
| if ecx.machine.basic_block_count % u64::from(report_progress) == 0 { |
| ecx.emit_diagnostic(NonHaltingDiagnostic::ProgressReport { |
| block_count: ecx.machine.basic_block_count, |
| }); |
| } |
| } |
| |
| // Search for BorTags to find all live pointers, then remove all other tags from borrow |
| // stacks. |
| // When debug assertions are enabled, run the GC as often as possible so that any cases |
| // where it mistakenly removes an important tag become visible. |
| if ecx.machine.gc_interval > 0 && ecx.machine.since_gc >= ecx.machine.gc_interval { |
| ecx.machine.since_gc = 0; |
| ecx.run_provenance_gc(); |
| } |
| |
| // These are our preemption points. |
| ecx.maybe_preempt_active_thread(); |
| |
| // Make sure some time passes. |
| ecx.machine.clock.tick(); |
| |
| interp_ok(()) |
| } |
| |
| #[inline(always)] |
| fn after_stack_push(ecx: &mut InterpCx<'tcx, Self>) -> InterpResult<'tcx> { |
| if ecx.frame().extra.is_user_relevant { |
| // We just pushed a local frame, so we know that the topmost local frame is the topmost |
| // frame. If we push a non-local frame, there's no need to do anything. |
| let stack_len = ecx.active_thread_stack().len(); |
| ecx.active_thread_mut().set_top_user_relevant_frame(stack_len - 1); |
| } |
| interp_ok(()) |
| } |
| |
| fn before_stack_pop( |
| ecx: &InterpCx<'tcx, Self>, |
| frame: &Frame<'tcx, Self::Provenance, Self::FrameExtra>, |
| ) -> InterpResult<'tcx> { |
| // We want this *before* the return value copy, because the return place itself is protected |
| // until we do `end_call` here. |
| if ecx.machine.borrow_tracker.is_some() { |
| ecx.on_stack_pop(frame)?; |
| } |
| // tracing-tree can autoamtically annotate scope changes, but it gets very confused by our |
| // concurrency and what it prints is just plain wrong. So we print our own information |
| // instead. (Cc https://github.com/rust-lang/miri/issues/2266) |
| info!("Leaving {}", ecx.frame().instance()); |
| interp_ok(()) |
| } |
| |
| #[inline(always)] |
| fn after_stack_pop( |
| ecx: &mut InterpCx<'tcx, Self>, |
| frame: Frame<'tcx, Provenance, FrameExtra<'tcx>>, |
| unwinding: bool, |
| ) -> InterpResult<'tcx, ReturnAction> { |
| if frame.extra.is_user_relevant { |
| // All that we store is whether or not the frame we just removed is local, so now we |
| // have no idea where the next topmost local frame is. So we recompute it. |
| // (If this ever becomes a bottleneck, we could have `push` store the previous |
| // user-relevant frame and restore that here.) |
| ecx.active_thread_mut().recompute_top_user_relevant_frame(); |
| } |
| let res = { |
| // Move `frame`` into a sub-scope so we control when it will be dropped. |
| let mut frame = frame; |
| let timing = frame.extra.timing.take(); |
| let res = ecx.handle_stack_pop_unwind(frame.extra, unwinding); |
| if let Some(profiler) = ecx.machine.profiler.as_ref() { |
| profiler.finish_recording_interval_event(timing.unwrap()); |
| } |
| res |
| }; |
| // Needs to be done after dropping frame to show up on the right nesting level. |
| // (Cc https://github.com/rust-lang/miri/issues/2266) |
| if !ecx.active_thread_stack().is_empty() { |
| info!("Continuing in {}", ecx.frame().instance()); |
| } |
| res |
| } |
| |
| fn after_local_read(ecx: &InterpCx<'tcx, Self>, local: mir::Local) -> InterpResult<'tcx> { |
| if let Some(data_race) = &ecx.frame().extra.data_race { |
| data_race.local_read(local, &ecx.machine); |
| } |
| interp_ok(()) |
| } |
| |
| fn after_local_write( |
| ecx: &mut InterpCx<'tcx, Self>, |
| local: mir::Local, |
| storage_live: bool, |
| ) -> InterpResult<'tcx> { |
| if let Some(data_race) = &ecx.frame().extra.data_race { |
| data_race.local_write(local, storage_live, &ecx.machine); |
| } |
| interp_ok(()) |
| } |
| |
| fn after_local_moved_to_memory( |
| ecx: &mut InterpCx<'tcx, Self>, |
| local: mir::Local, |
| mplace: &MPlaceTy<'tcx>, |
| ) -> InterpResult<'tcx> { |
| let Some(Provenance::Concrete { alloc_id, .. }) = mplace.ptr().provenance else { |
| panic!("after_local_allocated should only be called on fresh allocations"); |
| }; |
| // Record the span where this was allocated: the declaration of the local. |
| let local_decl = &ecx.frame().body().local_decls[local]; |
| let span = local_decl.source_info.span; |
| ecx.machine.allocation_spans.borrow_mut().insert(alloc_id, (span, None)); |
| // The data race system has to fix the clocks used for this write. |
| let (alloc_info, machine) = ecx.get_alloc_extra_mut(alloc_id)?; |
| if let Some(data_race) = |
| &machine.threads.active_thread_stack().last().unwrap().extra.data_race |
| { |
| data_race.local_moved_to_memory(local, alloc_info.data_race.as_mut().unwrap(), machine); |
| } |
| interp_ok(()) |
| } |
| |
| fn eval_mir_constant<F>( |
| ecx: &InterpCx<'tcx, Self>, |
| val: mir::Const<'tcx>, |
| span: Span, |
| layout: Option<TyAndLayout<'tcx>>, |
| eval: F, |
| ) -> InterpResult<'tcx, OpTy<'tcx>> |
| where |
| F: Fn( |
| &InterpCx<'tcx, Self>, |
| mir::Const<'tcx>, |
| Span, |
| Option<TyAndLayout<'tcx>>, |
| ) -> InterpResult<'tcx, OpTy<'tcx>>, |
| { |
| let frame = ecx.active_thread_stack().last().unwrap(); |
| let mut cache = ecx.machine.const_cache.borrow_mut(); |
| match cache.entry((val, frame.extra.salt)) { |
| Entry::Vacant(ve) => { |
| let op = eval(ecx, val, span, layout)?; |
| ve.insert(op.clone()); |
| interp_ok(op) |
| } |
| Entry::Occupied(oe) => interp_ok(oe.get().clone()), |
| } |
| } |
| |
| fn get_global_alloc_salt( |
| ecx: &InterpCx<'tcx, Self>, |
| instance: Option<ty::Instance<'tcx>>, |
| ) -> usize { |
| let unique = if let Some(instance) = instance { |
| // Functions cannot be identified by pointers, as asm-equal functions can get |
| // deduplicated by the linker (we set the "unnamed_addr" attribute for LLVM) and |
| // functions can be duplicated across crates. We thus generate a new `AllocId` for every |
| // mention of a function. This means that `main as fn() == main as fn()` is false, while |
| // `let x = main as fn(); x == x` is true. However, as a quality-of-life feature it can |
| // be useful to identify certain functions uniquely, e.g. for backtraces. So we identify |
| // whether codegen will actually emit duplicate functions. It does that when they have |
| // non-lifetime generics, or when they can be inlined. All other functions are given a |
| // unique address. This is not a stable guarantee! The `inline` attribute is a hint and |
| // cannot be relied upon for anything. But if we don't do this, the |
| // `__rust_begin_short_backtrace`/`__rust_end_short_backtrace` logic breaks and panic |
| // backtraces look terrible. |
| let is_generic = instance |
| .args |
| .into_iter() |
| .any(|kind| !matches!(kind.unpack(), ty::GenericArgKind::Lifetime(_))); |
| let can_be_inlined = matches!( |
| ecx.tcx.sess.opts.unstable_opts.cross_crate_inline_threshold, |
| InliningThreshold::Always |
| ) || !matches!( |
| ecx.tcx.codegen_fn_attrs(instance.def_id()).inline, |
| InlineAttr::Never |
| ); |
| !is_generic && !can_be_inlined |
| } else { |
| // Non-functions are never unique. |
| false |
| }; |
| // Always use the same salt if the allocation is unique. |
| if unique { |
| CTFE_ALLOC_SALT |
| } else { |
| ecx.machine.rng.borrow_mut().gen::<usize>() % ADDRS_PER_ANON_GLOBAL |
| } |
| } |
| |
| fn cached_union_data_range<'e>( |
| ecx: &'e mut InterpCx<'tcx, Self>, |
| ty: Ty<'tcx>, |
| compute_range: impl FnOnce() -> RangeSet, |
| ) -> Cow<'e, RangeSet> { |
| Cow::Borrowed(ecx.machine.union_data_ranges.entry(ty).or_insert_with(compute_range)) |
| } |
| } |
