base on An interpreter for Rust's mid-level intermediate representation # Miri Miri is an [Undefined Behavior][reference-ub] detection tool for Rust. It can run binaries and test suites of cargo projects and detect unsafe code that fails to uphold its safety requirements. For instance: * Out-of-bounds memory accesses and use-after-free * Invalid use of uninitialized data * Violation of intrinsic preconditions (an [`unreachable_unchecked`] being reached, calling [`copy_nonoverlapping`] with overlapping ranges, ...) * Not sufficiently aligned memory accesses and references * Violation of basic type invariants (a `bool` that is not 0 or 1, for example, or an invalid enum discriminant) * **Experimental**: Violations of the [Stacked Borrows] rules governing aliasing for reference types * **Experimental**: Violations of the [Tree Borrows] aliasing rules, as an optional alternative to [Stacked Borrows] * **Experimental**: Data races and emulation of weak memory effects, i.e., atomic reads can return outdated values. On top of that, Miri will also tell you about memory leaks: when there is memory still allocated at the end of the execution, and that memory is not reachable from a global `static`, Miri will raise an error. You can use Miri to emulate programs on other targets, e.g. to ensure that byte-level data manipulation works correctly both on little-endian and big-endian systems. See [cross-interpretation](#cross-interpretation-running-for-different-targets) below. Miri has already discovered many [real-world bugs](#bugs-found-by-miri). If you found a bug with Miri, we'd appreciate if you tell us and we'll add it to the list! By default, Miri ensures a fully deterministic execution and isolates the program from the host system. Some APIs that would usually access the host, such as gathering entropy for random number generators, environment variables, and clocks, are replaced by deterministic "fake" implementations. Set `MIRIFLAGS="-Zmiri-disable-isolation"` to access the real system APIs instead. (In particular, the "fake" system RNG APIs make Miri **not suited for cryptographic use**! Do not generate keys using Miri.) All that said, be aware that Miri does **not catch every violation of the Rust specification** in your program, not least because there is no such specification. Miri uses its own approximation of what is and is not Undefined Behavior in Rust. To the best of our knowledge, all Undefined Behavior that has the potential to affect a program's correctness *is* being detected by Miri (modulo [bugs][I-misses-ub]), but you should consult [the Reference][reference-ub] for the official definition of Undefined Behavior. Miri will be updated with the Rust compiler to protect against UB as it is understood by the current compiler, but it makes no promises about future versions of rustc. Further caveats that Miri users should be aware of: * If the program relies on unspecified details of how data is laid out, it will still run fine in Miri -- but might break (including causing UB) on different compiler versions or different platforms. (You can use `-Zrandomize-layout` to detect some of these cases.) * Program execution is non-deterministic when it depends, for example, on where exactly in memory allocations end up, or on the exact interleaving of concurrent threads. Miri tests one of many possible executions of your program, but it will miss bugs that only occur in a different possible execution. You can alleviate this to some extent by running Miri with different values for `-Zmiri-seed`, but that will still by far not explore all possible executions. * Miri runs the program as a platform-independent interpreter, so the program has no access to most platform-specific APIs or FFI. A few APIs have been implemented (such as printing to stdout, accessing environment variables, and basic file system access) but most have not: for example, Miri currently does not support networking. System API support varies between targets; if you run on Windows it is a good idea to use `--target x86_64-unknown-linux-gnu` to get better support. * Weak memory emulation is not complete: there are legal behaviors that Miri will never produce. However, Miri produces many behaviors that are hard to observe on real hardware, so it can help quite a bit in finding weak memory concurrency bugs. To be really sure about complicated atomic code, use specialized tools such as [loom](https://github.com/tokio-rs/loom). Moreover, Miri fundamentally cannot ensure that your code is *sound*. [Soundness] is the property of never causing undefined behavior when invoked from arbitrary safe code, even in combination with other sound code. In contrast, Miri can just tell you if *a particular way of interacting with your code* (e.g., a test suite) causes any undefined behavior *in a particular execution* (of which there may be many, e.g. when concurrency or other forms of non-determinism are involved). When Miri finds UB, your code is definitely unsound, but when Miri does not find UB, then you may just have to test more inputs or more possible non-deterministic choices. [rust]: https://www.rust-lang.org/ [mir]: https://github.com/rust-lang/rfcs/blob/master/text/1211-mir.md [`unreachable_unchecked`]: https://doc.rust-lang.org/stable/std/hint/fn.unreachable_unchecked.html [`copy_nonoverlapping`]: https://doc.rust-lang.org/stable/std/ptr/fn.copy_nonoverlapping.html [Stacked Borrows]: https://github.com/rust-lang/unsafe-code-guidelines/blob/master/wip/stacked-borrows.md [Tree Borrows]: https://perso.crans.org/vanille/treebor/ [Soundness]: https://rust-lang.github.io/unsafe-code-guidelines/glossary.html#soundness-of-code--of-a-library [reference-ub]: https://doc.rust-lang.org/reference/behavior-considered-undefined.html [I-misses-ub]: https://github.com/rust-lang/miri/labels/I-misses-UB ## Using Miri Install Miri on Rust nightly via `rustup`: ```sh rustup +nightly component add miri ``` All the following commands assume the nightly toolchain is pinned via `rustup override set nightly`. Alternatively, use `cargo +nightly` for each of the following commands. Now you can run your project in Miri: - To run all tests in your project through Miri, use `cargo miri test`. - If you have a binary project, you can run it through Miri using `cargo miri run`. The first time you run Miri, it will perform some extra setup and install some dependencies. It will ask you for confirmation before installing anything. `cargo miri run/test` supports the exact same flags as `cargo run/test`. For example, `cargo miri test filter` only runs the tests containing `filter` in their name. You can pass [flags][miri-flags] to Miri via `MIRIFLAGS`. For example, `MIRIFLAGS="-Zmiri-disable-stacked-borrows" cargo miri run` runs the program without checking the aliasing of references. When compiling code via `cargo miri`, the `cfg(miri)` config flag is set for code that will be interpreted under Miri. You can use this to ignore test cases that fail under Miri because they do things Miri does not support: ```rust #[test] #[cfg_attr(miri, ignore)] fn does_not_work_on_miri() { tokio::run(futures::future::ok::<_, ()>(())); } ``` There is no way to list all the infinite things Miri cannot do, but the interpreter will explicitly tell you when it finds something unsupported: ``` error: unsupported operation: can't call foreign function: bind ... = help: this is likely not a bug in the program; it indicates that the program \ performed an operation that Miri does not support ``` ### Cross-interpretation: running for different targets Miri can not only run a binary or test suite for your host target, it can also perform cross-interpretation for arbitrary foreign targets: `cargo miri run --target x86_64-unknown-linux-gnu` will run your program as if it was a Linux program, no matter your host OS. This is particularly useful if you are using Windows, as the Linux target is much better supported than Windows targets. You can also use this to test platforms with different properties than your host platform. For example `cargo miri test --target s390x-unknown-linux-gnu` will run your test suite on a big-endian target, which is useful for testing endian-sensitive code. ### Testing multiple different executions Certain parts of the execution are picked randomly by Miri, such as the exact base address allocations are stored at and the interleaving of concurrently executing threads. Sometimes, it can be useful to explore multiple different execution, e.g. to make sure that your code does not depend on incidental "super-alignment" of new allocations and to test different thread interleavings. This can be done with the `--many-seeds` flag: ``` cargo miri test --many-seeds # tries the seeds in 0..64 cargo miri test --many-seeds=0..16 ``` The default of 64 different seeds is quite slow, so you probably want to specify a smaller range. ### Running Miri on CI When running Miri on CI, use the following snippet to install a nightly toolchain with the Miri component: ```sh rustup toolchain install nightly --component miri rustup override set nightly cargo miri test ``` Here is an example job for GitHub Actions: ```yaml miri: name: "Miri" runs-on: ubuntu-latest steps: - uses: actions/checkout@v4 - name: Install Miri run: | rustup toolchain install nightly --component miri rustup override set nightly cargo miri setup - name: Test with Miri run: cargo miri test ``` The explicit `cargo miri setup` helps to keep the output of the actual test step clean. ### Supported targets Miri does not support all targets supported by Rust. The good news, however, is that no matter your host OS/platform, it is easy to run code for *any* target using `--target`! The following targets are tested on CI and thus should always work (to the degree documented below): - All Rust [Tier 1 targets](https://doc.rust-lang.org/rustc/platform-support.html) are supported by Miri. They are all checked on Miri's CI, and some (at least one per OS) are even checked on every Rust PR, so the shipped Miri should always work on these targets. - `s390x-unknown-linux-gnu` is supported as our "big-endian target of choice". - For every other target with OS `linux`, `macos`, or `windows`, Miri should generally work, but we make no promises and we don't run tests for such targets. - We have unofficial support (not maintained by the Miri team itself) for some further operating systems. - `solaris` / `illumos`: maintained by @devnexen. Supports `std::{env, thread, sync}`, but not `std::fs`. - `freebsd`: **maintainer wanted**. Supports `std::env` and parts of `std::{thread, fs}`, but not `std::sync`. - `android`: **maintainer wanted**. Support very incomplete, but a basic "hello world" works. - `wasi`: **maintainer wanted**. Support very incomplete, not even standard output works, but an empty `main` function works. - For targets on other operating systems, Miri might fail before even reaching the `main` function. However, even for targets that we do support, the degree of support for accessing platform APIs (such as the file system) differs between targets: generally, Linux targets have the best support, and macOS targets are usually on par. Windows is supported less well. ### Running tests in parallel Though it implements Rust threading, Miri itself is a single-threaded interpreter. This means that when running `cargo miri test`, you will probably see a dramatic increase in the amount of time it takes to run your whole test suite due to the inherent interpreter slowdown and a loss of parallelism. You can get your test suite's parallelism back by running `cargo miri nextest run -jN` (note that you will need [`cargo-nextest`](https://nexte.st) installed). This works because `cargo-nextest` collects a list of all tests then launches a separate `cargo miri run` for each test. You will need to specify a `-j` or `--test-threads`; by default `cargo miri nextest run` runs one test at a time. For more details, see the [`cargo-nextest` Miri documentation](https://nexte.st/book/miri.html). Note: This one-test-per-process model means that `cargo miri test` is able to detect data races where two tests race on a shared resource, but `cargo miri nextest run` will not detect such races. Note: `cargo-nextest` does not support doctests, see https://github.com/nextest-rs/nextest/issues/16 ### Common Problems When using the above instructions, you may encounter a number of confusing compiler errors. #### "note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace" You may see this when trying to get Miri to display a backtrace. By default, Miri doesn't expose any environment to the program, so running `RUST_BACKTRACE=1 cargo miri test` will not do what you expect. To get a backtrace, you need to disable isolation [using `-Zmiri-disable-isolation`][miri-flags]: ```sh RUST_BACKTRACE=1 MIRIFLAGS="-Zmiri-disable-isolation" cargo miri test ``` #### "found crate `std` compiled by an incompatible version of rustc" You may be running `cargo miri` with a different compiler version than the one used to build the custom libstd that Miri uses, and Miri failed to detect that. Try running `cargo miri clean`. ## Miri `-Z` flags and environment variables [miri-flags]: #miri--z-flags-and-environment-variables Miri adds its own set of `-Z` flags, which are usually set via the `MIRIFLAGS` environment variable. We first document the most relevant and most commonly used flags: * `-Zmiri-address-reuse-rate=<rate>` changes the probability that a freed *non-stack* allocation will be added to the pool for address reuse, and the probability that a new *non-stack* allocation will be taken from the pool. Stack allocations never get added to or taken from the pool. The default is `0.5`. * `-Zmiri-address-reuse-cross-thread-rate=<rate>` changes the probability that an allocation which attempts to reuse a previously freed block of memory will also consider blocks freed by *other threads*. The default is `0.1`, which means by default, in 90% of the cases where an address reuse attempt is made, only addresses from the same thread will be considered. Reusing an address from another thread induces synchronization between those threads, which can mask data races and weak memory bugs. * `-Zmiri-compare-exchange-weak-failure-rate=<rate>` changes the failure rate of `compare_exchange_weak` operations. The default is `0.8` (so 4 out of 5 weak ops will fail). You can change it to any value between `0.0` and `1.0`, where `1.0` means it will always fail and `0.0` means it will never fail. Note that setting it to `1.0` will likely cause hangs, since it means programs using `compare_exchange_weak` cannot make progress. * `-Zmiri-disable-isolation` disables host isolation. As a consequence, the program has access to host resources such as environment variables, file systems, and randomness. * `-Zmiri-disable-leak-backtraces` disables backtraces reports for memory leaks. By default, a backtrace is captured for every allocation when it is created, just in case it leaks. This incurs some memory overhead to store data that is almost never used. This flag is implied by `-Zmiri-ignore-leaks`. * `-Zmiri-env-forward=<var>` forwards the `var` environment variable to the interpreted program. Can be used multiple times to forward several variables. Execution will still be deterministic if the value of forwarded variables stays the same. Has no effect if `-Zmiri-disable-isolation` is set. * `-Zmiri-env-set=<var>=<value>` sets the `var` environment variable to `value` in the interpreted program. It can be used to pass environment variables without needing to alter the host environment. It can be used multiple times to set several variables. If `-Zmiri-disable-isolation` or `-Zmiri-env-forward` is set, values set with this option will have priority over values from the host environment. * `-Zmiri-ignore-leaks` disables the memory leak checker, and also allows some remaining threads to exist when the main thread exits. * `-Zmiri-isolation-error=<action>` configures Miri's response to operations requiring host access while isolation is enabled. `abort`, `hide`, `warn`, and `warn-nobacktrace` are the supported actions. The default is to `abort`, which halts the machine. Some (but not all) operations also support continuing execution with a "permission denied" error being returned to the program. `warn` prints a full backtrace each time that happens; `warn-nobacktrace` is less verbose and shown at most once per operation. `hide` hides the warning entirely. * `-Zmiri-num-cpus` states the number of available CPUs to be reported by miri. By default, the number of available CPUs is `1`. Note that this flag does not affect how miri handles threads in any way. * `-Zmiri-permissive-provenance` disables the warning for integer-to-pointer casts and [`ptr::with_exposed_provenance`](https://doc.rust-lang.org/nightly/std/ptr/fn.with_exposed_provenance.html). This will necessarily miss some bugs as those operations are not efficiently and accurately implementable in a sanitizer, but it will only miss bugs that concern memory/pointers which is subject to these operations. * `-Zmiri-preemption-rate` configures the probability that at the end of a basic block, the active thread will be preempted. The default is `0.01` (i.e., 1%). Setting this to `0` disables preemption. * `-Zmiri-report-progress` makes Miri print the current stacktrace every now and then, so you can tell what it is doing when a program just keeps running. You can customize how frequently the report is printed via `-Zmiri-report-progress=<blocks>`, which prints the report every N basic blocks. * `-Zmiri-seed=<num>` configures the seed of the RNG that Miri uses to resolve non-determinism. This RNG is used to pick base addresses for allocations, to determine preemption and failure of `compare_exchange_weak`, and to control store buffering for weak memory emulation. When isolation is enabled (the default), this is also used to emulate system entropy. The default seed is 0. You can increase test coverage by running Miri multiple times with different seeds. * `-Zmiri-strict-provenance` enables [strict provenance](https://github.com/rust-lang/rust/issues/95228) checking in Miri. This means that casting an integer to a pointer yields a result with 'invalid' provenance, i.e., with provenance that cannot be used for any memory access. * `-Zmiri-symbolic-alignment-check` makes the alignment check more strict. By default, alignment is checked by casting the pointer to an integer, and making sure that is a multiple of the alignment. This can lead to cases where a program passes the alignment check by pure chance, because things "happened to be" sufficiently aligned -- there is no UB in this execution but there would be UB in others. To avoid such cases, the symbolic alignment check only takes into account the requested alignment of the relevant allocation, and the offset into that allocation. This avoids missing such bugs, but it also incurs some false positives when the code does manual integer arithmetic to ensure alignment. (The standard library `align_to` method works fine in both modes; under symbolic alignment it only fills the middle slice when the allocation guarantees sufficient alignment.) The remaining flags are for advanced use only, and more likely to change or be removed. Some of these are **unsound**, which means they can lead to Miri failing to detect cases of undefined behavior in a program. * `-Zmiri-disable-alignment-check` disables checking pointer alignment, so you can focus on other failures, but it means Miri can miss bugs in your program. Using this flag is **unsound**. * `-Zmiri-disable-data-race-detector` disables checking for data races. Using this flag is **unsound**. This implies `-Zmiri-disable-weak-memory-emulation`. * `-Zmiri-disable-stacked-borrows` disables checking the experimental aliasing rules to track borrows ([Stacked Borrows] and [Tree Borrows]). This can make Miri run faster, but it also means no aliasing violations will be detected. Using this flag is **unsound** (but the affected soundness rules are experimental). Later flags take precedence: borrow tracking can be reactivated by `-Zmiri-tree-borrows`. * `-Zmiri-disable-validation` disables enforcing validity invariants, which are enforced by default. This is mostly useful to focus on other failures (such as out-of-bounds accesses) first. Setting this flag means Miri can miss bugs in your program. However, this can also help to make Miri run faster. Using this flag is **unsound**. * `-Zmiri-disable-weak-memory-emulation` disables the emulation of some C++11 weak memory effects. * `-Zmiri-native-lib=<path to a shared object file>` is an experimental flag for providing support for calling native functions from inside the interpreter via FFI. The flag is supported only on Unix systems. Functions not provided by that file are still executed via the usual Miri shims. **WARNING**: If an invalid/incorrect `.so` file is specified, this can cause Undefined Behavior in Miri itself! And of course, Miri cannot do any checks on the actions taken by the native code. Note that Miri has its own handling of file descriptors, so if you want to replace *some* functions working on file descriptors, you will have to replace *all* of them, or the two kinds of file descriptors will be mixed up. This is **work in progress**; currently, only integer and pointers arguments and return values are supported and memory allocated by the native code cannot be accessed from Rust (only the other way around). Native code must not spawn threads that keep running in the background after the call has returned to Rust and that access Rust-allocated memory. Finally, the flag is **unsound** in the sense that Miri stops tracking details such as initialization and provenance on memory shared with native code, so it is easily possible to write code that has UB which is missed by Miri. * `-Zmiri-measureme=<name>` enables `measureme` profiling for the interpreted program. This can be used to find which parts of your program are executing slowly under Miri. The profile is written out to a file inside a directory called `<name>`, and can be processed using the tools in the repository https://github.com/rust-lang/measureme. * `-Zmiri-mute-stdout-stderr` silently ignores all writes to stdout and stderr, but reports to the program that it did actually write. This is useful when you are not interested in the actual program's output, but only want to see Miri's errors and warnings. * `-Zmiri-recursive-validation` is a *highly experimental* flag that makes validity checking recurse below references. * `-Zmiri-retag-fields[=<all|none|scalar>]` controls when Stacked Borrows retagging recurses into fields. `all` means it always recurses (the default, and equivalent to `-Zmiri-retag-fields` without an explicit value), `none` means it never recurses, `scalar` means it only recurses for types where we would also emit `noalias` annotations in the generated LLVM IR (types passed as individual scalars or pairs of scalars). Setting this to `none` is **unsound**. * `-Zmiri-provenance-gc=<blocks>` configures how often the pointer provenance garbage collector runs. The default is to search for and remove unreachable provenance once every `10000` basic blocks. Setting this to `0` disables the garbage collector, which causes some programs to have explosive memory usage and/or super-linear runtime. * `-Zmiri-track-alloc-accesses` show not only allocation and free events for tracked allocations, but also reads and writes. * `-Zmiri-track-alloc-id=<id1>,<id2>,...` shows a backtrace when the given allocations are being allocated or freed. This helps in debugging memory leaks and use after free bugs. Specifying this argument multiple times does not overwrite the previous values, instead it appends its values to the list. Listing an id multiple times has no effect. * `-Zmiri-track-pointer-tag=<tag1>,<tag2>,...` shows a backtrace when a given pointer tag is created and when (if ever) it is popped from a borrow stack (which is where the tag becomes invalid and any future use of it will error). This helps you in finding out why UB is happening and where in your code would be a good place to look for it. Specifying this argument multiple times does not overwrite the previous values, instead it appends its values to the list. Listing a tag multiple times has no effect. * `-Zmiri-track-weak-memory-loads` shows a backtrace when weak memory emulation returns an outdated value from a load. This can help diagnose problems that disappear under `-Zmiri-disable-weak-memory-emulation`. * `-Zmiri-tree-borrows` replaces [Stacked Borrows] with the [Tree Borrows] rules. Tree Borrows is even more experimental than Stacked Borrows. While Tree Borrows is still sound in the sense of catching all aliasing violations that current versions of the compiler might exploit, it is likely that the eventual final aliasing model of Rust will be stricter than Tree Borrows. In other words, if you use Tree Borrows, even if your code is accepted today, it might be declared UB in the future. This is much less likely with Stacked Borrows. * `-Zmiri-force-page-size=<num>` overrides the default page size for an architecture, in multiples of 1k. `4` is default for most targets. This value should always be a power of 2 and nonzero. * `-Zmiri-unique-is-unique` performs additional aliasing checks for `core::ptr::Unique` to ensure that it could theoretically be considered `noalias`. This flag is experimental and has an effect only when used with `-Zmiri-tree-borrows`. [function ABI]: https://doc.rust-lang.org/reference/items/functions.html#extern-function-qualifier Some native rustc `-Z` flags are also very relevant for Miri: * `-Zmir-opt-level` controls how many MIR optimizations are performed. Miri overrides the default to be `0`; be advised that using any higher level can make Miri miss bugs in your program because they got optimized away. * `-Zalways-encode-mir` makes rustc dump MIR even for completely monomorphic functions. This is needed so that Miri can execute such functions, so Miri sets this flag per default. * `-Zmir-emit-retag` controls whether `Retag` statements are emitted. Miri enables this per default because it is needed for [Stacked Borrows] and [Tree Borrows]. Moreover, Miri recognizes some environment variables: * `MIRIFLAGS` defines extra flags to be passed to Miri. * `MIRI_LIB_SRC` defines the directory where Miri expects the sources of the standard library that it will build and use for interpretation. This directory must point to the `library` subdirectory of a `rust-lang/rust` repository checkout. * `MIRI_SYSROOT` indicates the sysroot to use. When using `cargo miri test`/`cargo miri run`, this skips the automatic setup -- only set this if you do not want to use the automatically created sysroot. When invoking `cargo miri setup`, this indicates where the sysroot will be put. * `MIRI_NO_STD` makes sure that the target's sysroot is built without libstd. This allows testing and running no_std programs. This should *not usually be used*; Miri has a heuristic to detect no-std targets based on the target name. Setting this on a target that does support libstd can lead to confusing results. [testing-miri]: CONTRIBUTING.md#testing-the-miri-driver ## Miri `extern` functions Miri provides some `extern` functions that programs can import to access Miri-specific functionality. They are declared in [/tests/utils/miri\_extern.rs](/tests/utils/miri_extern.rs). ## Entry point for no-std binaries Binaries that do not use the standard library are expected to declare a function like this so that Miri knows where it is supposed to start execution: ```rust #[cfg(miri)] #[no_mangle] fn miri_start(argc: isize, argv: *const *const u8) -> isize { // Call the actual start function that your project implements, based on your target's conventions. } ``` ## Contributing and getting help If you want to contribute to Miri, great! Please check out our [contribution guide](CONTRIBUTING.md). For help with running Miri, you can open an issue here on GitHub or use the [Miri stream on the Rust Zulip][zulip]. [zulip]: https://rust-lang.zulipchat.com/#narrow/stream/269128-miri ## History This project began as part of an undergraduate research course in 2015 by @solson at the [University of Saskatchewan][usask]. There are [slides] and a [report] available from that project. In 2016, @oli-obk joined to prepare Miri for eventually being used as const evaluator in the Rust compiler itself (basically, for `const` and `static` stuff), replacing the old evaluator that worked directly on the AST. In 2017, @RalfJung did an internship with Mozilla and began developing Miri towards a tool for detecting undefined behavior, and also using Miri as a way to explore the consequences of various possible definitions for undefined behavior in Rust. @oli-obk's move of the Miri engine into the compiler finally came to completion in early 2018. Meanwhile, later that year, @RalfJung did a second internship, developing Miri further with support for checking basic type invariants and verifying that references are used according to their aliasing restrictions. [usask]: https://www.usask.ca/ [slides]: https://solson.me/miri-slides.pdf [report]: https://solson.me/miri-report.pdf ## Bugs found by Miri Miri has already found a number of bugs in the Rust standard library and beyond, some of which we collect here. If Miri helped you find a subtle UB bug in your code, we'd appreciate a PR adding it to the list! Definite bugs found: * [`Debug for vec_deque::Iter` accessing uninitialized memory](https://github.com/rust-lang/rust/issues/53566) * [`Vec::into_iter` doing an unaligned ZST read](https://github.com/rust-lang/rust/pull/53804) * [`From<&[T]> for Rc` creating a not sufficiently aligned reference](https://github.com/rust-lang/rust/issues/54908) * [`BTreeMap` creating a shared reference pointing to a too small allocation](https://github.com/rust-lang/rust/issues/54957) * [`Vec::append` creating a dangling reference](https://github.com/rust-lang/rust/pull/61082) * [Futures turning a shared reference into a mutable one](https://github.com/rust-lang/rust/pull/56319) * [`str` turning a shared reference into a mutable one](https://github.com/rust-lang/rust/pull/58200) * [`rand` performing unaligned reads](https://github.com/rust-random/rand/issues/779) * [The Unix allocator calling `posix_memalign` in an invalid way](https://github.com/rust-lang/rust/issues/62251) * [`getrandom` calling the `getrandom` syscall in an invalid way](https://github.com/rust-random/getrandom/pull/73) * [`Vec`](https://github.com/rust-lang/rust/issues/69770) and [`BTreeMap`](https://github.com/rust-lang/rust/issues/69769) leaking memory under some (panicky) conditions * [`beef` leaking memory](https://github.com/maciejhirsz/beef/issues/12) * [`EbrCell` using uninitialized memory incorrectly](https://github.com/Firstyear/concread/commit/b15be53b6ec076acb295a5c0483cdb4bf9be838f#diff-6282b2fc8e98bd089a1f0c86f648157cR229) * [TiKV performing an unaligned pointer access](https://github.com/tikv/tikv/issues/7613) * [`servo_arc` creating a dangling shared reference](https://github.com/servo/servo/issues/26357) * [TiKV constructing out-of-bounds pointers (and overlapping mutable references)](https://github.com/tikv/tikv/pull/7751) * [`encoding_rs` doing out-of-bounds pointer arithmetic](https://github.com/hsivonen/encoding_rs/pull/53) * [TiKV using `Vec::from_raw_parts` incorrectly](https://github.com/tikv/agatedb/pull/24) * Incorrect doctests for [`AtomicPtr`](https://github.com/rust-lang/rust/pull/84052) and [`Box::from_raw_in`](https://github.com/rust-lang/rust/pull/84053) * [Insufficient alignment in `ThinVec`](https://github.com/Gankra/thin-vec/pull/27) * [`crossbeam-epoch` calling `assume_init` on a partly-initialized `MaybeUninit`](https://github.com/crossbeam-rs/crossbeam/pull/779) * [`integer-encoding` dereferencing a misaligned pointer](https://github.com/dermesser/integer-encoding-rs/pull/23) * [`rkyv` constructing a `Box<[u8]>` from an overaligned allocation](https://github.com/rkyv/rkyv/commit/a9417193a34757e12e24263178be8b2eebb72456) * [Data race in `arc-swap`](https://github.com/vorner/arc-swap/issues/76) * [Data race in `thread::scope`](https://github.com/rust-lang/rust/issues/98498) * [`regex` incorrectly handling unaligned `Vec<u8>` buffers](https://www.reddit.com/r/rust/comments/vq3mmu/comment/ienc7t0?context=3) * [Incorrect use of `compare_exchange_weak` in `once_cell`](https://github.com/matklad/once_cell/issues/186) * [Dropping with unaligned pointers in `vec::IntoIter`](https://github.com/rust-lang/rust/pull/106084) * [Deallocating with the wrong layout in new specializations for in-place `Iterator::collect`](https://github.com/rust-lang/rust/pull/118460) * [Incorrect offset computation for highly-aligned types in `portable-atomic-util`](https://github.com/taiki-e/portable-atomic/pull/138) * [Occasional memory leak in `std::mpsc` channels](https://github.com/rust-lang/rust/issues/121582) (original code in [crossbeam](https://github.com/crossbeam-rs/crossbeam/pull/1084)) * [Weak-memory-induced memory leak in Windows thread-local storage](https://github.com/rust-lang/rust/pull/124281) * [A bug in the new `RwLock::downgrade` implementation](https://rust-lang.zulipchat.com/#narrow/channel/269128-miri/topic/Miri.20error.20library.20test) (caught by Miri before it landed in the Rust repo) Violations of [Stacked Borrows] found that are likely bugs (but Stacked Borrows is currently just an experiment): * [`VecDeque::drain` creating overlapping mutable references](https://github.com/rust-lang/rust/pull/56161) * Various `BTreeMap` problems * [`BTreeMap` iterators creating mutable references that overlap with shared references](https://github.com/rust-lang/rust/pull/58431) * [`BTreeMap::iter_mut` creating overlapping mutable references](https://github.com/rust-lang/rust/issues/73915) * [`BTreeMap` node insertion using raw pointers outside their valid memory area](https://github.com/rust-lang/rust/issues/78477) * [`LinkedList` cursor insertion creating overlapping mutable references](https://github.com/rust-lang/rust/pull/60072) * [`Vec::push` invalidating existing references into the vector](https://github.com/rust-lang/rust/issues/60847) * [`align_to_mut` violating uniqueness of mutable references](https://github.com/rust-lang/rust/issues/68549) * [`sized-chunks` creating aliasing mutable references](https://github.com/bodil/sized-chunks/issues/8) * [`String::push_str` invalidating existing references into the string](https://github.com/rust-lang/rust/issues/70301) * [`ryu` using raw pointers outside their valid memory area](https://github.com/dtolnay/ryu/issues/24) * [ink! creating overlapping mutable references](https://github.com/rust-lang/miri/issues/1364) * [TiKV creating overlapping mutable reference and raw pointer](https://github.com/tikv/tikv/pull/7709) * [Windows `Env` iterator using a raw pointer outside its valid memory area](https://github.com/rust-lang/rust/pull/70479) * [`VecDeque::iter_mut` creating overlapping mutable references](https://github.com/rust-lang/rust/issues/74029) * [Various standard library aliasing issues involving raw pointers](https://github.com/rust-lang/rust/pull/78602) * [`<[T]>::copy_within` using a loan after invalidating it](https://github.com/rust-lang/rust/pull/85610) ## Scientific papers employing Miri * [Stacked Borrows: An Aliasing Model for Rust](https://plv.mpi-sws.org/rustbelt/stacked-borrows/) * [Using Lightweight Formal Methods to Validate a Key-Value Storage Node in Amazon S3](https://www.amazon.science/publications/using-lightweight-formal-methods-to-validate-a-key-value-storage-node-in-amazon-s3) * [SyRust: Automatic Testing of Rust Libraries with Semantic-Aware Program Synthesis](https://dl.acm.org/doi/10.1145/3453483.3454084) ## License Licensed under either of * Apache License, Version 2.0 ([LICENSE-APACHE](LICENSE-APACHE) or http://www.apache.org/licenses/LICENSE-2.0) * MIT license ([LICENSE-MIT](LICENSE-MIT) or http://opensource.org/licenses/MIT) at your option. ### Contribution Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you shall be dual licensed as above, without any additional terms or conditions. ", Assign "at most 3 tags" to the expected json: {"id":"4156","tags":[]} "only from the tags list I provide: [{"id":77,"name":"3d"},{"id":89,"name":"agent"},{"id":17,"name":"ai"},{"id":54,"name":"algorithm"},{"id":24,"name":"api"},{"id":44,"name":"authentication"},{"id":3,"name":"aws"},{"id":27,"name":"backend"},{"id":60,"name":"benchmark"},{"id":72,"name":"best-practices"},{"id":39,"name":"bitcoin"},{"id":37,"name":"blockchain"},{"id":1,"name":"blog"},{"id":45,"name":"bundler"},{"id":58,"name":"cache"},{"id":21,"name":"chat"},{"id":49,"name":"cicd"},{"id":4,"name":"cli"},{"id":64,"name":"cloud-native"},{"id":48,"name":"cms"},{"id":61,"name":"compiler"},{"id":68,"name":"containerization"},{"id":92,"name":"crm"},{"id":34,"name":"data"},{"id":47,"name":"database"},{"id":8,"name":"declarative-gui "},{"id":9,"name":"deploy-tool"},{"id":53,"name":"desktop-app"},{"id":6,"name":"dev-exp-lib"},{"id":59,"name":"dev-tool"},{"id":13,"name":"ecommerce"},{"id":26,"name":"editor"},{"id":66,"name":"emulator"},{"id":62,"name":"filesystem"},{"id":80,"name":"finance"},{"id":15,"name":"firmware"},{"id":73,"name":"for-fun"},{"id":2,"name":"framework"},{"id":11,"name":"frontend"},{"id":22,"name":"game"},{"id":81,"name":"game-engine "},{"id":23,"name":"graphql"},{"id":84,"name":"gui"},{"id":91,"name":"http"},{"id":5,"name":"http-client"},{"id":51,"name":"iac"},{"id":30,"name":"ide"},{"id":78,"name":"iot"},{"id":40,"name":"json"},{"id":83,"name":"julian"},{"id":38,"name":"k8s"},{"id":31,"name":"language"},{"id":10,"name":"learning-resource"},{"id":33,"name":"lib"},{"id":41,"name":"linter"},{"id":28,"name":"lms"},{"id":16,"name":"logging"},{"id":76,"name":"low-code"},{"id":90,"name":"message-queue"},{"id":42,"name":"mobile-app"},{"id":18,"name":"monitoring"},{"id":36,"name":"networking"},{"id":7,"name":"node-version"},{"id":55,"name":"nosql"},{"id":57,"name":"observability"},{"id":46,"name":"orm"},{"id":52,"name":"os"},{"id":14,"name":"parser"},{"id":74,"name":"react"},{"id":82,"name":"real-time"},{"id":56,"name":"robot"},{"id":65,"name":"runtime"},{"id":32,"name":"sdk"},{"id":71,"name":"search"},{"id":63,"name":"secrets"},{"id":25,"name":"security"},{"id":85,"name":"server"},{"id":86,"name":"serverless"},{"id":70,"name":"storage"},{"id":75,"name":"system-design"},{"id":79,"name":"terminal"},{"id":29,"name":"testing"},{"id":12,"name":"ui"},{"id":50,"name":"ux"},{"id":88,"name":"video"},{"id":20,"name":"web-app"},{"id":35,"name":"web-server"},{"id":43,"name":"webassembly"},{"id":69,"name":"workflow"},{"id":87,"name":"yaml"}]" returns me the "expected json"