Auto merge of #122246 - RalfJung:miri, r=RalfJung

Miri subtree update

r? `@ghost`

`@WaffleLapkin` when this lands, setting `MIRI_TEMP` should not be needed any more on the dev desktops.

35 files changed, 238 insertions, 260 deletions

diff --git a/src/tools/miri/.github/workflows/ci.yml b/src/tools/miri/.github/workflows/ci.yml
index 0954c57a1db..49ed7ffce22 100644
--- a/src/tools/miri/.github/workflows/ci.yml
+++ b/src/tools/miri/.github/workflows/ci.yml
@@ -187,7 +187,7 @@ jobs:
         run: RUSTFLAGS="--cap-lints warn" cargo +stable install josh-proxy --git https://github.com/josh-project/josh --tag r22.12.06
       - name: setup bot git name and email
         run: |
-          git config --global user.name 'The Miri Conjob Bot'
+          git config --global user.name 'The Miri Cronjob Bot'
           git config --global user.email 'miri@cron.bot'
       - name: get changes from rustc
         run: ./miri rustc-pull
diff --git a/src/tools/miri/Cargo.lock b/src/tools/miri/Cargo.lock
index 1adae2b7a22..4fb479e1c54 100644
--- a/src/tools/miri/Cargo.lock
+++ b/src/tools/miri/Cargo.lock
@@ -497,6 +497,7 @@ dependencies = [
  "regex",
  "rustc_version",
  "smallvec",
+ "tempfile",
  "ui_test",
 ]
 
diff --git a/src/tools/miri/Cargo.toml b/src/tools/miri/Cargo.toml
index 39122c847ce..041254e6f43 100644
--- a/src/tools/miri/Cargo.toml
+++ b/src/tools/miri/Cargo.toml
@@ -45,6 +45,7 @@ ui_test = "0.21.1"
 rustc_version = "0.4"
 regex = "1.5.5"
 lazy_static = "1.4.0"
+tempfile = "3"
 
 [package.metadata.rust-analyzer]
 # This crate uses #[feature(rustc_private)].
@@ -52,7 +53,7 @@ lazy_static = "1.4.0"
 rustc_private = true
 
 [[test]]
-name = "compiletest"
+name = "ui"
 harness = false
 
 [features]
diff --git a/src/tools/miri/README.md b/src/tools/miri/README.md
index 5eb8c0fa7c9..b043805291e 100644
--- a/src/tools/miri/README.md
+++ b/src/tools/miri/README.md
@@ -318,8 +318,8 @@ 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 happens; `warn-nobacktrace` is less
-  verbose. `hide` hides the warning entirely.
+  `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.
@@ -359,8 +359,6 @@ The remaining flags are for advanced use only, and more likely to change or be r
 Some of these are **unsound**, which means they can lead
 to Miri failing to detect cases of undefined behavior in a program.
 
-* `-Zmiri-disable-abi-check` disables checking [function ABI]. Using this flag
-  is **unsound**. This flag is **deprecated**.
 * `-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**.
@@ -465,11 +463,7 @@ Moreover, Miri recognizes some environment variables:
 * `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. Note that changing files in that directory does not automatically
-  trigger a re-build of the standard library; you have to clear the Miri build
-  cache with `cargo miri clean` or deleting it manually (on Linux, `rm -rf ~/.cache/miri`;
-  on Windows, `rmdir /S "%LOCALAPPDATA%\rust-lang\miri\cache"`;
-  and on macOS, `rm -rf ~/Library/Caches/org.rust-lang.miri`).
+  checkout.
 * `MIRI_SYSROOT` (recognized by `cargo miri` and the Miri driver) indicates the sysroot to use. When
   using `cargo miri`, this skips the automatic setup -- only set this if you do not want to use the
   automatically created sysroot. For directly invoking the Miri driver, this variable (or a
diff --git a/src/tools/miri/ci/build-all-targets.sh b/src/tools/miri/ci/build-all-targets.sh
index bf3ffd07017..fdb645c3ae1 100755
--- a/src/tools/miri/ci/build-all-targets.sh
+++ b/src/tools/miri/ci/build-all-targets.sh
@@ -12,7 +12,7 @@ PLATFORM_SUPPORT_FILE=$(rustc +miri --print sysroot)/share/doc/rust/html/rustc/p
 
 for target in $(python3 ci/scrape-targets.py $PLATFORM_SUPPORT_FILE); do
     # Wipe the cache before every build to minimize disk usage
-    rm -rf ~/.cache/miri
+    cargo +miri miri clean
     if cargo +miri miri setup --target $target 2>&1 | tee failures/$target; then
         # If the build succeeds, delete its output. If we have output, a build failed.
         rm $FAILS_DIR/$target
diff --git a/src/tools/miri/miri-script/src/commands.rs b/src/tools/miri/miri-script/src/commands.rs
index 88ee62fc18a..7fff6ae80b4 100644
--- a/src/tools/miri/miri-script/src/commands.rs
+++ b/src/tools/miri/miri-script/src/commands.rs
@@ -510,11 +510,11 @@ impl Command {
         let miri_flags = flagsplit(&miri_flags);
         let toolchain = &e.toolchain;
         let extra_flags = &e.cargo_extra_flags;
-        let edition_flags = (!have_edition).then_some("--edition=2021"); // keep in sync with `compiletest.rs`.`
+        let edition_flags = (!have_edition).then_some("--edition=2021"); // keep in sync with `tests/ui.rs`.`
         if dep {
             cmd!(
                 e.sh,
-                "cargo +{toolchain} --quiet test --test compiletest {extra_flags...} --manifest-path {miri_manifest} -- --miri-run-dep-mode {miri_flags...} {edition_flags...} {flags...}"
+                "cargo +{toolchain} --quiet test {extra_flags...} --manifest-path {miri_manifest} --test ui -- --miri-run-dep-mode {miri_flags...} {edition_flags...} {flags...}"
             ).quiet().run()?;
         } else {
             cmd!(
@@ -526,37 +526,27 @@ impl Command {
     }
 
     fn fmt(flags: Vec<OsString>) -> Result<()> {
+        use itertools::Itertools;
+
         let e = MiriEnv::new()?;
-        let toolchain = &e.toolchain;
         let config_path = path!(e.miri_dir / "rustfmt.toml");
 
-        let mut cmd = cmd!(
-            e.sh,
-            "rustfmt +{toolchain} --edition=2021 --config-path {config_path} --unstable-features --skip-children {flags...}"
-        );
-        eprintln!("$ {cmd} ...");
-
-        // Add all the filenames to the command.
-        // FIXME: `rustfmt` will follow the `mod` statements in these files, so we get a bunch of
-        // duplicate diffs.
-        for item in WalkDir::new(&e.miri_dir).into_iter().filter_entry(|entry| {
-            let name = entry.file_name().to_string_lossy();
-            let ty = entry.file_type();
-            if ty.is_file() {
-                name.ends_with(".rs")
-            } else {
-                // dir or symlink. skip `target` and `.git`.
-                &name != "target" && &name != ".git"
-            }
-        }) {
-            let item = item?;
-            if item.file_type().is_file() {
-                cmd = cmd.arg(item.into_path());
-            }
-        }
+        // Collect each rust file in the miri repo.
+        let files = WalkDir::new(&e.miri_dir)
+            .into_iter()
+            .filter_entry(|entry| {
+                let name = entry.file_name().to_string_lossy();
+                let ty = entry.file_type();
+                if ty.is_file() {
+                    name.ends_with(".rs")
+                } else {
+                    // dir or symlink. skip `target` and `.git`.
+                    &name != "target" && &name != ".git"
+                }
+            })
+            .filter_ok(|item| item.file_type().is_file())
+            .map_ok(|item| item.into_path());
 
-        // We want our own error message, repeating the command is too much.
-        cmd.quiet().run().map_err(|_| anyhow!("`rustfmt` failed"))?;
-        Ok(())
+        e.format_files(files, &e.toolchain[..], &config_path, &flags[..])
     }
 }
diff --git a/src/tools/miri/miri-script/src/util.rs b/src/tools/miri/miri-script/src/util.rs
index 420ecdab63c..361a4ca0cf7 100644
--- a/src/tools/miri/miri-script/src/util.rs
+++ b/src/tools/miri/miri-script/src/util.rs
@@ -1,7 +1,7 @@
 use std::ffi::{OsStr, OsString};
-use std::path::PathBuf;
+use std::path::{Path, PathBuf};
 
-use anyhow::{Context, Result};
+use anyhow::{anyhow, Context, Result};
 use dunce::canonicalize;
 use path_macro::path;
 use xshell::{cmd, Shell};
@@ -145,4 +145,48 @@ impl MiriEnv {
         .run()?;
         Ok(())
     }
+
+    /// Receives an iterator of files.
+    /// Will format each file with the miri rustfmt config.
+    /// Does not recursively format modules.
+    pub fn format_files(
+        &self,
+        files: impl Iterator<Item = Result<PathBuf, walkdir::Error>>,
+        toolchain: &str,
+        config_path: &Path,
+        flags: &[OsString],
+    ) -> anyhow::Result<()> {
+        use itertools::Itertools;
+
+        let mut first = true;
+
+        // Format in batches as not all our files fit into Windows' command argument limit.
+        for batch in &files.chunks(256) {
+            // Build base command.
+            let mut cmd = cmd!(
+                self.sh,
+                "rustfmt +{toolchain} --edition=2021 --config-path {config_path} --unstable-features --skip-children {flags...}"
+            );
+            if first {
+                // Log an abbreviating command, and only once.
+                eprintln!("$ {cmd} ...");
+                first = false;
+            }
+            // Add files.
+            for file in batch {
+                // Make it a relative path so that on platforms with extremely tight argument
+                // limits (like Windows), we become immune to someone cloning the repo
+                // 50 directories deep.
+                let file = file?;
+                let file = file.strip_prefix(&self.miri_dir)?;
+                cmd = cmd.arg(file);
+            }
+
+            // Run rustfmt.
+            // We want our own error message, repeating the command is too much.
+            cmd.quiet().run().map_err(|_| anyhow!("`rustfmt` failed"))?;
+        }
+
+        Ok(())
+    }
 }
diff --git a/src/tools/miri/rust-version b/src/tools/miri/rust-version
index 75124dc8ff5..e23293ea558 100644
--- a/src/tools/miri/rust-version
+++ b/src/tools/miri/rust-version
@@ -1 +1 @@
-1a1876c9790f168fb51afa335a7ba3e6fc267d75
+4d4bb491b65c300835442f6cb4f34fc9a5685c26
diff --git a/src/tools/miri/src/bin/miri.rs b/src/tools/miri/src/bin/miri.rs
index a9b5aa5f1ef..6955e649b4d 100644
--- a/src/tools/miri/src/bin/miri.rs
+++ b/src/tools/miri/src/bin/miri.rs
@@ -8,6 +8,11 @@
     rustc::untranslatable_diagnostic
 )]
 
+// Some "regular" crates we want to share with rustc
+#[macro_use]
+extern crate tracing;
+
+// The rustc crates we need
 extern crate rustc_data_structures;
 extern crate rustc_driver;
 extern crate rustc_hir;
@@ -16,8 +21,6 @@ extern crate rustc_log;
 extern crate rustc_metadata;
 extern crate rustc_middle;
 extern crate rustc_session;
-#[macro_use]
-extern crate tracing;
 
 use std::env::{self, VarError};
 use std::num::NonZero;
@@ -202,16 +205,12 @@ fn rustc_logger_config() -> rustc_log::LoggerConfig {
             // rustc traced, but you can also do `MIRI_LOG=miri=trace,rustc_const_eval::interpret=debug`.
             if tracing::Level::from_str(&var).is_ok() {
                 cfg.filter = Ok(format!(
-                    "rustc_middle::mir::interpret={var},rustc_const_eval::interpret={var}"
+                    "rustc_middle::mir::interpret={var},rustc_const_eval::interpret={var},miri={var}"
                 ));
             } else {
                 cfg.filter = Ok(var);
             }
         }
-        // Enable verbose entry/exit logging by default if MIRI_LOG is set.
-        if matches!(cfg.verbose_entry_exit, Err(VarError::NotPresent)) {
-            cfg.verbose_entry_exit = Ok(format!("1"));
-        }
     }
 
     cfg
@@ -342,7 +341,8 @@ fn main() {
     // (`install_ice_hook` might change `RUST_BACKTRACE`.)
     let env_snapshot = env::vars_os().collect::<Vec<_>>();
 
-    let args = rustc_driver::args::raw_args(&early_dcx).unwrap_or_else(|_| std::process::exit(rustc_driver::EXIT_FAILURE));
+    let args = rustc_driver::args::raw_args(&early_dcx)
+        .unwrap_or_else(|_| std::process::exit(rustc_driver::EXIT_FAILURE));
 
     // If the environment asks us to actually be rustc, then do that.
     if let Some(crate_kind) = env::var_os("MIRI_BE_RUSTC") {
@@ -408,17 +408,11 @@ fn main() {
             miri_config.check_alignment = miri::AlignmentCheck::None;
         } else if arg == "-Zmiri-symbolic-alignment-check" {
             miri_config.check_alignment = miri::AlignmentCheck::Symbolic;
-        } else if arg == "-Zmiri-check-number-validity" {
-            eprintln!(
-                "WARNING: the flag `-Zmiri-check-number-validity` no longer has any effect \
-                        since it is now enabled by default"
-            );
         } else if arg == "-Zmiri-disable-abi-check" {
             eprintln!(
-                "WARNING: the flag `-Zmiri-disable-abi-check` is deprecated and planned to be removed.\n\
-                If you have a use-case for it, please file an issue."
+                "WARNING: the flag `-Zmiri-disable-abi-check` no longer has any effect; \
+                    ABI checks cannot be disabled any more"
             );
-            miri_config.check_abi = false;
         } else if arg == "-Zmiri-disable-isolation" {
             if matches!(isolation_enabled, Some(true)) {
                 show_error!(
@@ -459,8 +453,6 @@ fn main() {
             miri_config.collect_leak_backtraces = false;
         } else if arg == "-Zmiri-panic-on-unsupported" {
             miri_config.panic_on_unsupported = true;
-        } else if arg == "-Zmiri-tag-raw-pointers" {
-            eprintln!("WARNING: `-Zmiri-tag-raw-pointers` has no effect; it is enabled by default");
         } else if arg == "-Zmiri-strict-provenance" {
             miri_config.provenance_mode = ProvenanceMode::Strict;
         } else if arg == "-Zmiri-permissive-provenance" {
@@ -476,10 +468,6 @@ fn main() {
                 "scalar" => RetagFields::OnlyScalar,
                 _ => show_error!("`-Zmiri-retag-fields` can only be `all`, `none`, or `scalar`"),
             };
-        } else if arg == "-Zmiri-track-raw-pointers" {
-            eprintln!(
-                "WARNING: `-Zmiri-track-raw-pointers` has no effect; it is enabled by default"
-            );
         } else if let Some(param) = arg.strip_prefix("-Zmiri-seed=") {
             if miri_config.seed.is_some() {
                 show_error!("Cannot specify -Zmiri-seed multiple times!");
diff --git a/src/tools/miri/src/concurrency/thread.rs b/src/tools/miri/src/concurrency/thread.rs
index 83ca27a467c..805c0580b2f 100644
--- a/src/tools/miri/src/concurrency/thread.rs
+++ b/src/tools/miri/src/concurrency/thread.rs
@@ -445,10 +445,13 @@ impl<'mir, 'tcx: 'mir> ThreadManager<'mir, 'tcx> {
 
     /// Set an active thread and return the id of the thread that was active before.
     fn set_active_thread_id(&mut self, id: ThreadId) -> ThreadId {
-        let active_thread_id = self.active_thread;
-        self.active_thread = id;
-        assert!(self.active_thread.index() < self.threads.len());
-        active_thread_id
+        assert!(id.index() < self.threads.len());
+        info!(
+            "---------- Now executing on thread `{}` (previous: `{}`) ----------------------------------------",
+            self.get_thread_display_name(id),
+            self.get_thread_display_name(self.active_thread)
+        );
+        std::mem::replace(&mut self.active_thread, id)
     }
 
     /// Get the id of the currently active thread.
@@ -735,6 +738,11 @@ impl<'mir, 'tcx: 'mir> ThreadManager<'mir, 'tcx> {
         for (id, thread) in threads {
             debug_assert_ne!(self.active_thread, id);
             if thread.state == ThreadState::Enabled {
+                info!(
+                    "---------- Now executing on thread `{}` (previous: `{}`) ----------------------------------------",
+                    self.get_thread_display_name(id),
+                    self.get_thread_display_name(self.active_thread)
+                );
                 self.active_thread = id;
                 break;
             }
@@ -882,7 +890,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
             instance,
             start_abi,
             &[*func_arg],
-            Some(&ret_place.into()),
+            Some(&ret_place),
             StackPopCleanup::Root { cleanup: true },
         )?;
 
diff --git a/src/tools/miri/src/eval.rs b/src/tools/miri/src/eval.rs
index ef50bd43de3..f7edbdb9c5e 100644
--- a/src/tools/miri/src/eval.rs
+++ b/src/tools/miri/src/eval.rs
@@ -94,8 +94,6 @@ pub struct MiriConfig {
     pub unique_is_unique: bool,
     /// Controls alignment checking.
     pub check_alignment: AlignmentCheck,
-    /// Controls function [ABI](Abi) checking.
-    pub check_abi: bool,
     /// Action for an op requiring communication with the host.
     pub isolated_op: IsolatedOp,
     /// Determines if memory leaks should be ignored.
@@ -162,7 +160,6 @@ impl Default for MiriConfig {
             borrow_tracker: Some(BorrowTrackerMethod::StackedBorrows),
             unique_is_unique: false,
             check_alignment: AlignmentCheck::Int,
-            check_abi: true,
             isolated_op: IsolatedOp::Reject(RejectOpWith::Abort),
             ignore_leaks: false,
             forwarded_env_vars: vec![],
@@ -394,7 +391,7 @@ pub fn create_ecx<'mir, 'tcx: 'mir>(
                     argv,
                     Scalar::from_u8(sigpipe).into(),
                 ],
-                Some(&ret_place.into()),
+                Some(&ret_place),
                 StackPopCleanup::Root { cleanup: true },
             )?;
         }
@@ -403,7 +400,7 @@ pub fn create_ecx<'mir, 'tcx: 'mir>(
                 entry_instance,
                 Abi::Rust,
                 &[argc.into(), argv],
-                Some(&ret_place.into()),
+                Some(&ret_place),
                 StackPopCleanup::Root { cleanup: true },
             )?;
         }
diff --git a/src/tools/miri/src/helpers.rs b/src/tools/miri/src/helpers.rs
index 9e4b5fe8ad7..5e9de3ffb80 100644
--- a/src/tools/miri/src/helpers.rs
+++ b/src/tools/miri/src/helpers.rs
@@ -1,6 +1,8 @@
 use std::cmp;
+use std::collections::BTreeSet;
 use std::iter;
 use std::num::NonZero;
+use std::sync::Mutex;
 use std::time::Duration;
 
 use rustc_apfloat::ieee::{Double, Single};
@@ -387,7 +389,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
         let this = self.eval_context_mut();
         let param_env = ty::ParamEnv::reveal_all(); // in Miri this is always the param_env we use... and this.param_env is private.
         let callee_abi = f.ty(*this.tcx, param_env).fn_sig(*this.tcx).abi();
-        if this.machine.enforce_abi && callee_abi != caller_abi {
+        if callee_abi != caller_abi {
             throw_ub_format!(
                 "calling a function with ABI {} using caller ABI {}",
                 callee_abi.name(),
@@ -399,7 +401,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
         let mir = this.load_mir(f.def, None)?;
         let dest = match dest {
             Some(dest) => dest.clone(),
-            None => MPlaceTy::fake_alloc_zst(this.layout_of(mir.return_ty())?).into(),
+            None => MPlaceTy::fake_alloc_zst(this.layout_of(mir.return_ty())?),
         };
         this.push_stack_frame(f, mir, &dest, stack_pop)?;
 
@@ -603,9 +605,18 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
         match reject_with {
             RejectOpWith::Abort => isolation_abort_error(op_name),
             RejectOpWith::WarningWithoutBacktrace => {
-                this.tcx
-                    .dcx()
-                    .warn(format!("{op_name} was made to return an error due to isolation"));
+                // This exists to reduce verbosity; make sure we emit the warning at most once per
+                // operation.
+                static EMITTED_WARNINGS: Mutex<BTreeSet<String>> = Mutex::new(BTreeSet::new());
+
+                let mut emitted_warnings = EMITTED_WARNINGS.lock().unwrap();
+                if !emitted_warnings.contains(op_name) {
+                    // First time we are seeing this.
+                    emitted_warnings.insert(op_name.to_owned());
+                    this.tcx
+                        .dcx()
+                        .warn(format!("{op_name} was made to return an error due to isolation"));
+                }
                 Ok(())
             }
             RejectOpWith::Warning => {
@@ -945,7 +956,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
 
     /// Check that the ABI is what we expect.
     fn check_abi<'a>(&self, abi: Abi, exp_abi: Abi) -> InterpResult<'a, ()> {
-        if self.eval_context_ref().machine.enforce_abi && abi != exp_abi {
+        if abi != exp_abi {
             throw_ub_format!(
                 "calling a function with ABI {} using caller ABI {}",
                 exp_abi.name(),
@@ -1091,20 +1102,17 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
             }
         }
 
-        let (val, status) = match src.layout.ty.kind() {
-            // f32
-            ty::Float(FloatTy::F32) =>
+        let ty::Float(fty) = src.layout.ty.kind() else {
+            bug!("float_to_int_checked: non-float input type {}", src.layout.ty)
+        };
+
+        let (val, status) = match fty {
+            FloatTy::F16 => unimplemented!("f16_f128"),
+            FloatTy::F32 =>
                 float_to_int_inner::<Single>(this, src.to_scalar().to_f32()?, cast_to, round),
-            // f64
-            ty::Float(FloatTy::F64) =>
+            FloatTy::F64 =>
                 float_to_int_inner::<Double>(this, src.to_scalar().to_f64()?, cast_to, round),
-            // Nothing else
-            _ =>
-                span_bug!(
-                    this.cur_span(),
-                    "attempted float-to-int conversion with non-float input type {}",
-                    src.layout.ty,
-                ),
+            FloatTy::F128 => unimplemented!("f16_f128"),
         };
 
         if status.intersects(
diff --git a/src/tools/miri/src/lib.rs b/src/tools/miri/src/lib.rs
index e1d0bc1c183..c3bd6b912d5 100644
--- a/src/tools/miri/src/lib.rs
+++ b/src/tools/miri/src/lib.rs
@@ -49,8 +49,12 @@
 // Needed for rustdoc from bootstrap (with `-Znormalize-docs`).
 #![recursion_limit = "256"]
 
-extern crate either; // the one from rustc
+// Some "regular" crates we want to share with rustc
+extern crate either;
+#[macro_use]
+extern crate tracing;
 
+// The rustc crates we need
 extern crate rustc_apfloat;
 extern crate rustc_ast;
 extern crate rustc_const_eval;
@@ -63,11 +67,8 @@ extern crate rustc_middle;
 extern crate rustc_session;
 extern crate rustc_span;
 extern crate rustc_target;
-#[macro_use]
-extern crate tracing;
-
-// Necessary to pull in object code as the rest of the rustc crates are shipped only as rmeta
-// files.
+// Linking `rustc_driver` pulls in the required  object code as the rest of the rustc crates are
+// shipped only as rmeta files.
 #[allow(unused_extern_crates)]
 extern crate rustc_driver;
 
@@ -143,4 +144,7 @@ pub const MIRI_DEFAULT_ARGS: &[&str] = &[
     "-Zmir-keep-place-mention",
     "-Zmir-opt-level=0",
     "-Zmir-enable-passes=-CheckAlignment",
+    // Deduplicating diagnostics means we miss events when tracking what happens during an
+    // execution. Let's not do that.
+    "-Zdeduplicate-diagnostics=no",
 ];
diff --git a/src/tools/miri/src/machine.rs b/src/tools/miri/src/machine.rs
index 19d02c6f746..f0e3c43a5c5 100644
--- a/src/tools/miri/src/machine.rs
+++ b/src/tools/miri/src/machine.rs
@@ -462,9 +462,6 @@ pub struct MiriMachine<'mir, 'tcx> {
     /// Whether to enforce the validity invariant.
     pub(crate) validate: bool,
 
-    /// Whether to enforce [ABI](Abi) of function calls.
-    pub(crate) enforce_abi: bool,
-
     /// The table of file descriptors.
     pub(crate) file_handler: shims::unix::FileHandler,
     /// The table of directory descriptors.
@@ -643,7 +640,6 @@ impl<'mir, 'tcx> MiriMachine<'mir, 'tcx> {
             tls: TlsData::default(),
             isolated_op: config.isolated_op,
             validate: config.validate,
-            enforce_abi: config.check_abi,
             file_handler: FileHandler::new(config.mute_stdout_stderr),
             dir_handler: Default::default(),
             layouts,
@@ -786,7 +782,6 @@ impl VisitProvenance for MiriMachine<'_, '_> {
             tcx: _,
             isolated_op: _,
             validate: _,
-            enforce_abi: _,
             clock: _,
             layouts: _,
             static_roots: _,
@@ -934,8 +929,8 @@ impl<'mir, 'tcx> Machine<'mir, 'tcx> for MiriMachine<'mir, 'tcx> {
     }
 
     #[inline(always)]
-    fn enforce_abi(ecx: &MiriInterpCx<'mir, 'tcx>) -> bool {
-        ecx.machine.enforce_abi
+    fn enforce_abi(_ecx: &MiriInterpCx<'mir, 'tcx>) -> bool {
+        true
     }
 
     #[inline(always)]
@@ -1338,7 +1333,7 @@ impl<'mir, 'tcx> Machine<'mir, 'tcx> for MiriMachine<'mir, '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)?.into()
+            ecx.protect_place(place)?
         } else {
             // No borrow tracker.
             place.clone()
@@ -1447,13 +1442,17 @@ impl<'mir, 'tcx> Machine<'mir, 'tcx> for MiriMachine<'mir, 'tcx> {
         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);
         Ok(())
     }
 
     #[inline(always)]
     fn after_stack_pop(
         ecx: &mut InterpCx<'mir, 'tcx, Self>,
-        mut frame: Frame<'mir, 'tcx, Provenance, FrameExtra<'tcx>>,
+        frame: Frame<'mir, 'tcx, Provenance, FrameExtra<'tcx>>,
         unwinding: bool,
     ) -> InterpResult<'tcx, StackPopJump> {
         if frame.extra.is_user_relevant {
@@ -1463,10 +1462,20 @@ impl<'mir, 'tcx> Machine<'mir, 'tcx> for MiriMachine<'mir, 'tcx> {
             // user-relevant frame and restore that here.)
             ecx.active_thread_mut().recompute_top_user_relevant_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());
+        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
     }
diff --git a/src/tools/miri/src/shims/intrinsics/mod.rs b/src/tools/miri/src/shims/intrinsics/mod.rs
index 075ce44fbce..976d4b4de55 100644
--- a/src/tools/miri/src/shims/intrinsics/mod.rs
+++ b/src/tools/miri/src/shims/intrinsics/mod.rs
@@ -287,13 +287,14 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
                     _ => bug!(),
                 };
                 let float_finite = |x: &ImmTy<'tcx, _>| -> InterpResult<'tcx, bool> {
-                    Ok(match x.layout.ty.kind() {
-                        ty::Float(FloatTy::F32) => x.to_scalar().to_f32()?.is_finite(),
-                        ty::Float(FloatTy::F64) => x.to_scalar().to_f64()?.is_finite(),
-                        _ => bug!(
-                            "`{intrinsic_name}` called with non-float input type {ty:?}",
-                            ty = x.layout.ty,
-                        ),
+                    let ty::Float(fty) = x.layout.ty.kind() else {
+                        bug!("float_finite: non-float input type {}", x.layout.ty)
+                    };
+                    Ok(match fty {
+                        FloatTy::F16 => unimplemented!("f16_f128"),
+                        FloatTy::F32 => x.to_scalar().to_f32()?.is_finite(),
+                        FloatTy::F64 => x.to_scalar().to_f64()?.is_finite(),
+                        FloatTy::F128 => unimplemented!("f16_f128"),
                     })
                 };
                 match (float_finite(&a)?, float_finite(&b)?) {
diff --git a/src/tools/miri/src/shims/windows/sync.rs b/src/tools/miri/src/shims/windows/sync.rs
index c0a79e959a6..5edc18af482 100644
--- a/src/tools/miri/src/shims/windows/sync.rs
+++ b/src/tools/miri/src/shims/windows/sync.rs
@@ -179,7 +179,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
 
         let id = this.init_once_get_id(init_once_op)?;
         let flags = this.read_scalar(flags_op)?.to_u32()?;
-        let pending_place = this.deref_pointer(pending_op)?.into();
+        let pending_place = this.deref_pointer(pending_op)?;
         let context = this.read_pointer(context_op)?;
 
         if flags != 0 {
diff --git a/src/tools/miri/test_dependencies/Cargo.lock b/src/tools/miri/test_dependencies/Cargo.lock
index 9d9db7b0498..11d430bad15 100644
--- a/src/tools/miri/test_dependencies/Cargo.lock
+++ b/src/tools/miri/test_dependencies/Cargo.lock
@@ -183,9 +183,9 @@ dependencies = [
 
 [[package]]
 name = "mio"
-version = "0.8.10"
+version = "0.8.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8f3d0b296e374a4e6f3c7b0a1f5a51d748a0d34c85e7dc48fc3fa9a87657fe09"
+checksum = "a4a650543ca06a924e8b371db273b2756685faae30f8487da1b56505a8f78b0c"
 dependencies = [
  "libc",
  "wasi 0.11.0+wasi-snapshot-preview1",
diff --git a/src/tools/miri/tests/fail-dep/concurrency/unwind_top_of_stack.rs b/src/tools/miri/tests/fail-dep/concurrency/unwind_top_of_stack.rs
deleted file mode 100644
index 4704cfed039..00000000000
--- a/src/tools/miri/tests/fail-dep/concurrency/unwind_top_of_stack.rs
+++ /dev/null
@@ -1,29 +0,0 @@
-//@ignore-target-windows: No libc on Windows
-
-//@compile-flags: -Zmiri-disable-abi-check
-
-//! Unwinding past the top frame of a stack is Undefined Behavior.
-
-#![feature(c_unwind)]
-
-use std::{mem, ptr};
-
-extern "C-unwind" fn thread_start(_null: *mut libc::c_void) -> *mut libc::c_void {
-    //~^ ERROR: unwinding past the topmost frame of the stack
-    panic!()
-}
-
-fn main() {
-    unsafe {
-        let mut native: libc::pthread_t = mem::zeroed();
-        let attr: libc::pthread_attr_t = mem::zeroed();
-        // assert_eq!(libc::pthread_attr_init(&mut attr), 0); FIXME: this function is not yet implemented.
-        // Cast to avoid inserting abort-on-unwind.
-        let thread_start: extern "C-unwind" fn(*mut libc::c_void) -> *mut libc::c_void =
-            thread_start;
-        let thread_start: extern "C" fn(*mut libc::c_void) -> *mut libc::c_void =
-            mem::transmute(thread_start);
-        assert_eq!(libc::pthread_create(&mut native, &attr, thread_start, ptr::null_mut()), 0);
-        assert_eq!(libc::pthread_join(native, ptr::null_mut()), 0);
-    }
-}
diff --git a/src/tools/miri/tests/fail-dep/concurrency/unwind_top_of_stack.stderr b/src/tools/miri/tests/fail-dep/concurrency/unwind_top_of_stack.stderr
deleted file mode 100644
index 0c755215c00..00000000000
--- a/src/tools/miri/tests/fail-dep/concurrency/unwind_top_of_stack.stderr
+++ /dev/null
@@ -1,21 +0,0 @@
-WARNING: the flag `-Zmiri-disable-abi-check` is deprecated and planned to be removed.
-If you have a use-case for it, please file an issue.
-thread '<unnamed>' panicked at $DIR/unwind_top_of_stack.rs:LL:CC:
-explicit panic
-note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
-error: Undefined Behavior: unwinding past the topmost frame of the stack
-  --> $DIR/unwind_top_of_stack.rs:LL:CC
-   |
-LL | / extern "C-unwind" fn thread_start(_null: *mut libc::c_void) -> *mut libc::c_void {
-LL | |
-LL | |     panic!()
-LL | | }
-   | |_^ unwinding past the topmost frame of the stack
-   |
-   = help: this indicates a bug in the program: it performed an invalid operation, and caused Undefined Behavior
-   = help: see https://doc.rust-lang.org/nightly/reference/behavior-considered-undefined.html for further information
-   = note: BACKTRACE on thread `unnamed-ID`:
-   = note: inside `thread_start` at $DIR/unwind_top_of_stack.rs:LL:CC
-
-error: aborting due to 1 previous error
-
diff --git a/src/tools/miri/tests/fail/const-ub-checks.stderr b/src/tools/miri/tests/fail/const-ub-checks.stderr
index 700a96a9062..f6ac480f069 100644
--- a/src/tools/miri/tests/fail/const-ub-checks.stderr
+++ b/src/tools/miri/tests/fail/const-ub-checks.stderr
@@ -10,6 +10,14 @@ note: erroneous constant encountered
 LL |     let _x = UNALIGNED_READ;
    |              ^^^^^^^^^^^^^^
 
+note: erroneous constant encountered
+  --> $DIR/const-ub-checks.rs:LL:CC
+   |
+LL |     let _x = UNALIGNED_READ;
+   |              ^^^^^^^^^^^^^^
+   |
+   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
+
 error: aborting due to 1 previous error
 
 For more information about this error, try `rustc --explain E0080`.
diff --git a/src/tools/miri/tests/fail/erroneous_const2.stderr b/src/tools/miri/tests/fail/erroneous_const2.stderr
index 47b06fa8aaa..22274367074 100644
--- a/src/tools/miri/tests/fail/erroneous_const2.stderr
+++ b/src/tools/miri/tests/fail/erroneous_const2.stderr
@@ -16,6 +16,14 @@ note: erroneous constant encountered
 LL |     println!("{}", FOO);
    |                    ^^^
    |
+   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
+
+note: erroneous constant encountered
+  --> $DIR/erroneous_const2.rs:LL:CC
+   |
+LL |     println!("{}", FOO);
+   |                    ^^^
+   |
    = note: this note originates in the macro `$crate::format_args_nl` which comes from the expansion of the macro `println` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: aborting due to 1 previous error
diff --git a/src/tools/miri/tests/fail/function_calls/arg_inplace_mutate.rs b/src/tools/miri/tests/fail/function_calls/arg_inplace_mutate.rs
index 8a5c10913b4..4f7a12ebd2e 100644
--- a/src/tools/miri/tests/fail/function_calls/arg_inplace_mutate.rs
+++ b/src/tools/miri/tests/fail/function_calls/arg_inplace_mutate.rs
@@ -19,7 +19,6 @@ fn main() {
         after_call = {
             Return()
         }
-
     }
 }
 
diff --git a/src/tools/miri/tests/fail/function_calls/arg_inplace_mutate.stack.stderr b/src/tools/miri/tests/fail/function_calls/arg_inplace_mutate.stack.stderr
index 422dc243436..e0d1bed6332 100644
--- a/src/tools/miri/tests/fail/function_calls/arg_inplace_mutate.stack.stderr
+++ b/src/tools/miri/tests/fail/function_calls/arg_inplace_mutate.stack.stderr
@@ -14,7 +14,7 @@ LL | |         let _unit: ();
 LL | |         {
 LL | |             let non_copy = S(42);
 ...  |
-LL | |
+LL | |         }
 LL | |     }
    | |_____^
 help: <TAG> is this argument
diff --git a/src/tools/miri/tests/fail/function_calls/arg_inplace_mutate.tree.stderr b/src/tools/miri/tests/fail/function_calls/arg_inplace_mutate.tree.stderr
index 354631bdcb5..c187d24e5e8 100644
--- a/src/tools/miri/tests/fail/function_calls/arg_inplace_mutate.tree.stderr
+++ b/src/tools/miri/tests/fail/function_calls/arg_inplace_mutate.tree.stderr
@@ -16,7 +16,7 @@ LL | |         let _unit: ();
 LL | |         {
 LL | |             let non_copy = S(42);
 ...  |
-LL | |
+LL | |         }
 LL | |     }
    | |_____^
 help: the protected tag <TAG> was created here, in the initial state Reserved
diff --git a/src/tools/miri/tests/fail/function_calls/exported_symbol_bad_unwind1.rs b/src/tools/miri/tests/fail/function_calls/exported_symbol_bad_unwind1.rs
index 5f4df7c6a1e..6d68b9a46d9 100644
--- a/src/tools/miri/tests/fail/function_calls/exported_symbol_bad_unwind1.rs
+++ b/src/tools/miri/tests/fail/function_calls/exported_symbol_bad_unwind1.rs
@@ -1,4 +1,3 @@
-//@compile-flags: -Zmiri-disable-abi-check
 #![feature(c_unwind)]
 
 #[no_mangle]
diff --git a/src/tools/miri/tests/fail/function_calls/exported_symbol_bad_unwind1.stderr b/src/tools/miri/tests/fail/function_calls/exported_symbol_bad_unwind1.stderr
index c5ca1274574..ab32883a035 100644
--- a/src/tools/miri/tests/fail/function_calls/exported_symbol_bad_unwind1.stderr
+++ b/src/tools/miri/tests/fail/function_calls/exported_symbol_bad_unwind1.stderr
@@ -1,5 +1,3 @@
-WARNING: the flag `-Zmiri-disable-abi-check` is deprecated and planned to be removed.
-If you have a use-case for it, please file an issue.
 thread 'main' panicked at $DIR/exported_symbol_bad_unwind1.rs:LL:CC:
 explicit panic
 note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
diff --git a/src/tools/miri/tests/fail/panic/bad_miri_start_unwind.rs b/src/tools/miri/tests/fail/panic/bad_miri_start_unwind.rs
deleted file mode 100644
index deca836a36c..00000000000
--- a/src/tools/miri/tests/fail/panic/bad_miri_start_unwind.rs
+++ /dev/null
@@ -1,12 +0,0 @@
-//@compile-flags: -Zmiri-disable-abi-check
-// This feature is required to trigger the error using the "C" ABI.
-#![feature(c_unwind)]
-
-extern "C" {
-    fn miri_start_unwind(payload: *mut u8) -> !;
-}
-
-fn main() {
-    unsafe { miri_start_unwind(&mut 0) }
-    //~^ ERROR: unwinding past a stack frame that does not allow unwinding
-}
diff --git a/src/tools/miri/tests/fail/panic/bad_miri_start_unwind.stderr b/src/tools/miri/tests/fail/panic/bad_miri_start_unwind.stderr
deleted file mode 100644
index 6c85aac050a..00000000000
--- a/src/tools/miri/tests/fail/panic/bad_miri_start_unwind.stderr
+++ /dev/null
@@ -1,17 +0,0 @@
-WARNING: the flag `-Zmiri-disable-abi-check` is deprecated and planned to be removed.
-If you have a use-case for it, please file an issue.
-error: Undefined Behavior: unwinding past a stack frame that does not allow unwinding
-  --> $DIR/bad_miri_start_unwind.rs:LL:CC
-   |
-LL |     unsafe { miri_start_unwind(&mut 0) }
-   |              ^^^^^^^^^^^^^^^^^^^^^^^^^ unwinding past a stack frame that does not allow unwinding
-   |
-   = help: this indicates a bug in the program: it performed an invalid operation, and caused Undefined Behavior
-   = help: see https://doc.rust-lang.org/nightly/reference/behavior-considered-undefined.html for further information
-   = note: BACKTRACE:
-   = note: inside `main` at $DIR/bad_miri_start_unwind.rs:LL:CC
-
-note: some details are omitted, run with `MIRIFLAGS=-Zmiri-backtrace=full` for a verbose backtrace
-
-error: aborting due to 1 previous error
-
diff --git a/src/tools/miri/tests/fail/panic/bad_unwind.rs b/src/tools/miri/tests/fail/panic/bad_unwind.rs
index 370b372a7d3..8c8a9f18cdc 100644
--- a/src/tools/miri/tests/fail/panic/bad_unwind.rs
+++ b/src/tools/miri/tests/fail/panic/bad_unwind.rs
@@ -1,6 +1,9 @@
 #![feature(c_unwind)]
 
 //! Unwinding when the caller ABI is "C" (without "-unwind") is UB.
+// The opposite version (callee does not allow unwinding) is impossible to
+// even write: MIR validation catches functions that have `UnwindContinue` but
+// are not allowed to unwind.
 
 extern "C-unwind" fn unwind() {
     panic!();
diff --git a/src/tools/miri/tests/pass-dep/concurrency/linux-futex.rs b/src/tools/miri/tests/pass-dep/concurrency/linux-futex.rs
index 648c004c97c..d21f953672d 100644
--- a/src/tools/miri/tests/pass-dep/concurrency/linux-futex.rs
+++ b/src/tools/miri/tests/pass-dep/concurrency/linux-futex.rs
@@ -219,6 +219,7 @@ fn wait_wake_bitset() {
     t.join().unwrap();
 }
 
+// Crucial test which relies on the SeqCst fences in futex wait/wake.
 fn concurrent_wait_wake() {
     const FREE: i32 = 0;
     const HELD: i32 = 1;
diff --git a/src/tools/miri/tests/pass/concurrency/sync.rs b/src/tools/miri/tests/pass/concurrency/sync.rs
index a6c181098b7..91c67b215a1 100644
--- a/src/tools/miri/tests/pass/concurrency/sync.rs
+++ b/src/tools/miri/tests/pass/concurrency/sync.rs
@@ -7,6 +7,10 @@ use std::sync::{Arc, Barrier, Condvar, Mutex, Once, RwLock};
 use std::thread;
 use std::time::{Duration, Instant};
 
+// We are expecting to sleep for 10ms. How long of a sleep we are accepting?
+// Even with 1000ms we still see this test fail on macOS runners.
+const MAX_SLEEP_TIME_MS: u64 = 2000;
+
 // Check if Rust barriers are working.
 
 /// This test is taken from the Rust documentation.
@@ -66,7 +70,7 @@ fn check_conditional_variables_timed_wait_timeout() {
     let (_guard, timeout) = cvar.wait_timeout(guard, Duration::from_millis(10)).unwrap();
     assert!(timeout.timed_out());
     let elapsed_time = now.elapsed().as_millis();
-    assert!(10 <= elapsed_time && elapsed_time <= 1000);
+    assert!(10 <= elapsed_time && elapsed_time <= MAX_SLEEP_TIME_MS.into());
 }
 
 /// Test that signaling a conditional variable when waiting with a timeout works
@@ -84,7 +88,8 @@ fn check_conditional_variables_timed_wait_notimeout() {
         cvar.notify_one();
     });
 
-    let (_guard, timeout) = cvar.wait_timeout(guard, Duration::from_millis(1000)).unwrap();
+    let (_guard, timeout) =
+        cvar.wait_timeout(guard, Duration::from_millis(MAX_SLEEP_TIME_MS)).unwrap();
     assert!(!timeout.timed_out());
     handle.join().unwrap();
 }
@@ -213,20 +218,21 @@ fn check_once() {
 fn park_timeout() {
     let start = Instant::now();
 
-    thread::park_timeout(Duration::from_millis(200));
+    thread::park_timeout(Duration::from_millis(10));
     // Normally, waiting in park/park_timeout may spuriously wake up early, but we
     // know Miri's timed synchronization primitives do not do that.
-    // We allow much longer sleeps as well since the macOS GHA runners seem very oversubscribed
-    // and sometimes just pause for 1 second or more.
     let elapsed = start.elapsed();
-    assert!((200..2000).contains(&elapsed.as_millis()), "bad sleep time: {elapsed:?}");
+    assert!(
+        (10..MAX_SLEEP_TIME_MS.into()).contains(&elapsed.as_millis()),
+        "bad sleep time: {elapsed:?}"
+    );
 }
 
 fn park_unpark() {
     let t1 = thread::current();
     let t2 = thread::spawn(move || {
         thread::park();
-        thread::sleep(Duration::from_millis(200));
+        thread::sleep(Duration::from_millis(10));
         t1.unpark();
     });
 
@@ -236,10 +242,11 @@ fn park_unpark() {
     thread::park();
     // Normally, waiting in park/park_timeout may spuriously wake up early, but we
     // know Miri's timed synchronization primitives do not do that.
-    // We allow much longer sleeps as well since the macOS GHA runners seem very oversubscribed
-    // and sometimes just pause for 1 second or more.
     let elapsed = start.elapsed();
-    assert!((200..2000).contains(&elapsed.as_millis()), "bad sleep time: {elapsed:?}");
+    assert!(
+        (10..MAX_SLEEP_TIME_MS.into()).contains(&elapsed.as_millis()),
+        "bad sleep time: {elapsed:?}"
+    );
 
     t2.join().unwrap();
 }
diff --git a/src/tools/miri/tests/pass/function_calls/disable_abi_check.rs b/src/tools/miri/tests/pass/function_calls/disable_abi_check.rs
deleted file mode 100644
index 0f41047c603..00000000000
--- a/src/tools/miri/tests/pass/function_calls/disable_abi_check.rs
+++ /dev/null
@@ -1,24 +0,0 @@
-//@compile-flags: -Zmiri-disable-abi-check
-#![feature(core_intrinsics)]
-
-fn main() {
-    fn foo() {}
-
-    extern "C" fn try_fn(ptr: *mut u8) {
-        assert!(ptr.is_null());
-    }
-
-    extern "Rust" {
-        fn malloc(size: usize) -> *mut std::ffi::c_void;
-    }
-
-    unsafe {
-        let _ = malloc(0);
-        std::mem::transmute::<fn(), extern "C" fn()>(foo)();
-        std::intrinsics::catch_unwind(
-            std::mem::transmute::<extern "C" fn(*mut u8), _>(try_fn),
-            std::ptr::null_mut(),
-            |_, _| unreachable!(),
-        );
-    }
-}
diff --git a/src/tools/miri/tests/pass/function_calls/disable_abi_check.stderr b/src/tools/miri/tests/pass/function_calls/disable_abi_check.stderr
deleted file mode 100644
index e5b84f6d709..00000000000
--- a/src/tools/miri/tests/pass/function_calls/disable_abi_check.stderr
+++ /dev/null
@@ -1,2 +0,0 @@
-WARNING: the flag `-Zmiri-disable-abi-check` is deprecated and planned to be removed.
-If you have a use-case for it, please file an issue.
diff --git a/src/tools/miri/tests/pass/shims/fs.rs b/src/tools/miri/tests/pass/shims/fs.rs
index 304a178dc34..d10faebac7d 100644
--- a/src/tools/miri/tests/pass/shims/fs.rs
+++ b/src/tools/miri/tests/pass/shims/fs.rs
@@ -295,7 +295,7 @@ fn test_canonicalize() {
     drop(File::create(&path).unwrap());
 
     let p = canonicalize(format!("{}/./test_file", dir_path.to_string_lossy())).unwrap();
-    assert_eq!(p.to_string_lossy().find('.'), None);
+    assert_eq!(p.to_string_lossy().find("/./"), None);
 
     remove_dir_all(&dir_path).unwrap();
 }
diff --git a/src/tools/miri/tests/compiletest.rs b/src/tools/miri/tests/ui.rs
index db0768848fd..7f363ccdfe5 100644
--- a/src/tools/miri/tests/compiletest.rs
+++ b/src/tools/miri/tests/ui.rs
@@ -79,13 +79,6 @@ fn test_config(target: &str, path: &str, mode: Mode, with_dependencies: bool) ->
         program.args.push(flag);
     }
 
-    // Add a test env var to do environment communication tests.
-    program.envs.push(("MIRI_ENV_VAR_TEST".into(), Some("0".into())));
-
-    // Let the tests know where to store temp files (they might run for a different target, which can make this hard to find).
-    let miri_temp = env::var_os("MIRI_TEMP").unwrap_or_else(|| env::temp_dir().into());
-    program.envs.push(("MIRI_TEMP".into(), Some(miri_temp)));
-
     let mut config = Config {
         target: Some(target.to_owned()),
         stderr_filters: STDERR.clone(),
@@ -116,9 +109,21 @@ fn test_config(target: &str, path: &str, mode: Mode, with_dependencies: bool) ->
     config
 }
 
-fn run_tests(mode: Mode, path: &str, target: &str, with_dependencies: bool) -> Result<()> {
+fn run_tests(
+    mode: Mode,
+    path: &str,
+    target: &str,
+    with_dependencies: bool,
+    tmpdir: &Path,
+) -> Result<()> {
     let mut config = test_config(target, path, mode, with_dependencies);
 
+    // Add a test env var to do environment communication tests.
+    config.program.envs.push(("MIRI_ENV_VAR_TEST".into(), Some("0".into())));
+
+    // Let the tests know where to store temp files (they might run for a different target, which can make this hard to find).
+    config.program.envs.push(("MIRI_TEMP".into(), Some(tmpdir.to_owned().into())));
+
     // Handle command-line arguments.
     let args = ui_test::Args::test()?;
     let default_bless = env::var_os("RUSTC_BLESS").is_some_and(|v| v != "0");
@@ -211,7 +216,13 @@ enum Dependencies {
 
 use Dependencies::*;
 
-fn ui(mode: Mode, path: &str, target: &str, with_dependencies: Dependencies) -> Result<()> {
+fn ui(
+    mode: Mode,
+    path: &str,
+    target: &str,
+    with_dependencies: Dependencies,
+    tmpdir: &Path,
+) -> Result<()> {
     let msg = format!("## Running ui tests in {path} against miri for {target}");
     eprintln!("{}", msg.green().bold());
 
@@ -219,7 +230,7 @@ fn ui(mode: Mode, path: &str, target: &str, with_dependencies: Dependencies) ->
         WithDependencies => true,
         WithoutDependencies => false,
     };
-    run_tests(mode, path, target, with_dependencies)
+    run_tests(mode, path, target, with_dependencies, tmpdir)
 }
 
 fn get_target() -> String {
@@ -230,6 +241,7 @@ fn main() -> Result<()> {
     ui_test::color_eyre::install()?;
 
     let target = get_target();
+    let tmpdir = tempfile::Builder::new().prefix("miri-uitest-").tempdir()?;
 
     let mut args = std::env::args_os();
 
@@ -240,28 +252,31 @@ fn main() -> Result<()> {
         }
     }
 
-    ui(Mode::Pass, "tests/pass", &target, WithoutDependencies)?;
-    ui(Mode::Pass, "tests/pass-dep", &target, WithDependencies)?;
-    ui(Mode::Panic, "tests/panic", &target, WithDependencies)?;
+    ui(Mode::Pass, "tests/pass", &target, WithoutDependencies, tmpdir.path())?;
+    ui(Mode::Pass, "tests/pass-dep", &target, WithDependencies, tmpdir.path())?;
+    ui(Mode::Panic, "tests/panic", &target, WithDependencies, tmpdir.path())?;
     ui(
         Mode::Fail { require_patterns: true, rustfix: RustfixMode::Disabled },
         "tests/fail",
         &target,
         WithoutDependencies,
+        tmpdir.path(),
     )?;
     ui(
         Mode::Fail { require_patterns: true, rustfix: RustfixMode::Disabled },
         "tests/fail-dep",
         &target,
         WithDependencies,
+        tmpdir.path(),
     )?;
     if cfg!(target_os = "linux") {
-        ui(Mode::Pass, "tests/extern-so/pass", &target, WithoutDependencies)?;
+        ui(Mode::Pass, "tests/extern-so/pass", &target, WithoutDependencies, tmpdir.path())?;
         ui(
             Mode::Fail { require_patterns: true, rustfix: RustfixMode::Disabled },
             "tests/extern-so/fail",
             &target,
             WithoutDependencies,
+            tmpdir.path(),
         )?;
     }