X-Git-Url: https://git.lizzy.rs/?a=blobdiff_plain;f=README.md;h=52934a6cd4bc021d639564b47c4c831752cae4aa;hb=afa1dddcf97cf6008cfb447739b4b61e04f86660;hp=d7c50e9613fd02ceea62b229689cd2a315dbdf05;hpb=4120425108855824356019cc3e7f6c2bfff157c1;p=rust.git diff --git a/README.md b/README.md index d7c50e9613f..52934a6cd4b 100644 --- a/README.md +++ b/README.md @@ -65,9 +65,9 @@ in your program, and cannot run all programs: 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 may produce weak behaivours unobservable by compiled - programs running on real hardware when `SeqCst` fences are used, and it cannot - produce all behaviors possibly observable on real hardware. +* Weak memory emulation may [produce weak behaivours](https://github.com/rust-lang/miri/issues/2301) + unobservable by compiled programs running on real hardware when `SeqCst` fences are used, and it + cannot produce all behaviors possibly observable on real hardware. [rust]: https://www.rust-lang.org/ [mir]: https://github.com/rust-lang/rfcs/blob/master/text/1211-mir.md @@ -192,8 +192,9 @@ randomness that is used to determine allocation base addresses. The following snippet calls Miri in a loop with different values for the seed: ``` -for seed in $({ echo obase=16; seq 0 255; } | bc); do - MIRIFLAGS=-Zmiri-seed=$seed cargo miri test || { echo "Last seed: $seed"; break; }; +for SEED in $({ echo obase=16; seq 0 255; } | bc); do + echo "Trying seed: $SEED" + MIRIFLAGS=-Zmiri-seed=$SEED cargo miri test || { echo "Failing seed: $SEED"; break; }; done ``` @@ -277,7 +278,7 @@ environment variable. We first document the most relevant and most commonly used 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 when that happen; `warn-nobacktrace` is less + `warn` prints a full backtrace when that happens; `warn-nobacktrace` is less verbose. `hide` hides the warning entirely. * `-Zmiri-env-exclude=` keeps the `var` environment variable isolated from the host so that it cannot be accessed by the program. Can be used multiple times to exclude several variables. The @@ -285,8 +286,9 @@ environment variable. We first document the most relevant and most commonly used harness](https://github.com/rust-lang/miri/issues/1702). This has no effect unless `-Zmiri-disable-isolation` is also set. * `-Zmiri-env-forward=` forwards the `var` environment variable to the interpreted program. Can - be used multiple times to forward several variables. This has no effect if - `-Zmiri-disable-isolation` is set. + be used multiple times to forward several variables. This takes precedence over + `-Zmiri-env-exclude`: if a variable is both forwarded and exluced, it *will* get forwarded. This + means in particular `-Zmiri-env-forward=TERM` overwrites the default exclusion of `TERM`. * `-Zmiri-ignore-leaks` disables the memory leak checker, and also allows some remaining threads to exist when the main thread exits. * `-Zmiri-permissive-provenance` disables the warning for integer-to-pointer casts and @@ -369,6 +371,9 @@ to Miri failing to detect cases of undefined behavior in a program. application instead of raising an error within the context of Miri (and halting execution). Note that code might not expect these operations to ever panic, so this flag can lead to strange (mis)behavior. +* `-Zmiri-retag-fields` changes Stacked Borrows retagging to recurse into fields. + This means that references in fields of structs/enums/tuples/arrays/... are retagged, + and in particular, they are protected when passed as function arguments. * `-Zmiri-track-alloc-id=,,...` 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 @@ -378,8 +383,8 @@ to Miri failing to detect cases of undefined behavior in a program. Borrows "protectors". 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=,,...` shows a backtrace when a given pointer tag - 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 + 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. @@ -413,9 +418,11 @@ Moreover, Miri recognizes some environment variables: sysroot to use. Only set this if you do not want to use the automatically created sysroot. (The `miri` driver sysroot is controlled via the `--sysroot` flag instead.) -* `MIRI_TEST_TARGET` (recognized by the test suite) indicates which target - architecture to test against. `miri` and `cargo miri` accept the `--target` - flag for the same purpose. +* `MIRI_TEST_TARGET` (recognized by the test suite and the `./miri` script) indicates which target + architecture to test against. `miri` and `cargo miri` accept the `--target` flag for the same + purpose. +* `MIRI_NO_STD` (recognized by `cargo miri` and the test suite) makes sure that the target's + sysroot is built without libstd. This allows testing and running no_std programs. * `MIRI_BLESS` (recognized by the test suite) overwrite all `stderr` and `stdout` files instead of checking whether the output matches. * `MIRI_SKIP_UI_CHECKS` (recognized by the test suite) don't check whether the @@ -574,6 +581,8 @@ Definite bugs found: * [`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 `thread::scope`](https://github.com/rust-lang/rust/issues/98498) +* [`regex` incorrectly handling unaligned `Vec` 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) Violations of [Stacked Borrows] found that are likely bugs (but Stacked Borrows is currently just an experiment):