Auto merge of #125580 - RalfJung:miri-sync, r=RalfJung

Miri subtree update

r? `@ghost`

src/tools/miri/ci/ci.sh

@@ -148,8 +148,8 @@ case $HOST_TARGET in
     UNIX="panic/panic panic/unwind concurrency/simple atomic libc-mem libc-misc libc-random env num_cpus" # the things that are very similar across all Unixes, and hence easily supported there
     TEST_TARGET=x86_64-unknown-freebsd run_tests_minimal $BASIC $UNIX threadname libc-time fs
     TEST_TARGET=i686-unknown-freebsd   run_tests_minimal $BASIC $UNIX threadname libc-time fs
-    TEST_TARGET=x86_64-unknown-illumos run_tests_minimal $BASIC $UNIX pthread-sync
-    TEST_TARGET=x86_64-pc-solaris      run_tests_minimal $BASIC $UNIX pthread-sync
+    TEST_TARGET=x86_64-unknown-illumos run_tests_minimal $BASIC $UNIX threadname pthread-sync libc-time
+    TEST_TARGET=x86_64-pc-solaris      run_tests_minimal $BASIC $UNIX threadname pthread-sync libc-time
     TEST_TARGET=aarch64-linux-android  run_tests_minimal $BASIC $UNIX
     TEST_TARGET=wasm32-wasip2          run_tests_minimal empty_main wasm heap_alloc libc-mem
     TEST_TARGET=wasm32-unknown-unknown run_tests_minimal empty_main wasm

src/tools/miri/miri-script/src/commands.rs

@@ -531,7 +531,13 @@ impl Command {
             };
             cmd.set_quiet(!verbose);
             // Add Miri flags
-            let cmd = cmd.args(&miri_flags).args(&seed_flag).args(&early_flags).args(&flags);
+            let mut cmd = cmd.args(&miri_flags).args(&seed_flag).args(&early_flags).args(&flags);
+            // For `--dep` we also need to set the env var.
+            if dep {
+                if let Some(target) = &target {
+                    cmd = cmd.env("MIRI_TEST_TARGET", target);
+                }
+            }
             // And run the thing.
             Ok(cmd.run()?)
         };

src/tools/miri/rust-version

@@ -1 +1 @@
-6579ed89f0fcc26da71afdd11d30d63f6f812a0a
+21e6de7eb64c09102de3f100420a09edc1a2a8d7

src/tools/miri/src/alloc_addresses/mod.rs

@@ -169,12 +169,10 @@ trait EvalContextExtPriv<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
                     size,
                     align,
                     memory_kind,
-                    ecx.get_active_thread(),
+                    ecx.active_thread(),
                 ) {
-                    if let Some(clock) = clock
-                        && let Some(data_race) = &ecx.machine.data_race
-                    {
-                        data_race.acquire_clock(&clock, ecx.get_active_thread());
+                    if let Some(clock) = clock {
+                        ecx.acquire_clock(&clock);
                     }
                     reuse_addr
                 } else {
@@ -369,12 +367,10 @@ impl<'mir, 'tcx> MiriMachine<'mir, 'tcx> {
         // `alloc_id_from_addr` any more.
         global_state.exposed.remove(&dead_id);
         // Also remember this address for future reuse.
-        let thread = self.threads.get_active_thread_id();
+        let thread = self.threads.active_thread();
         global_state.reuse.add_addr(rng, addr, size, align, kind, thread, || {
             if let Some(data_race) = &self.data_race {
-                data_race
-                    .release_clock(thread, self.threads.active_thread_ref().current_span())
-                    .clone()
+                data_race.release_clock(&self.threads).clone()
             } else {
                 VClock::default()
             }

src/tools/miri/src/alloc_bytes.rs

@@ -14,8 +14,7 @@ pub struct MiriAllocBytes {
     layout: alloc::Layout,
     /// Pointer to the allocation contents.
     /// Invariant:
-    /// * If `self.layout.size() == 0`, then `self.ptr` is some suitably aligned pointer
-    ///   without provenance (and no actual memory was allocated).
+    /// * If `self.layout.size() == 0`, then `self.ptr` was allocated with the equivalent layout with size 1.
     /// * Otherwise, `self.ptr` points to memory allocated with `self.layout`.
     ptr: *mut u8,
 }
@@ -30,10 +29,15 @@ impl Clone for MiriAllocBytes {
 
 impl Drop for MiriAllocBytes {
     fn drop(&mut self) {
-        if self.layout.size() != 0 {
-            // SAFETY: Invariant, `self.ptr` points to memory allocated with `self.layout`.
-            unsafe { alloc::dealloc(self.ptr, self.layout) }
-        }
+        // We have to reconstruct the actual layout used for allocation.
+        // (`Deref` relies on `size` so we can't just always set it to at least 1.)
+        let alloc_layout = if self.layout.size() == 0 {
+            Layout::from_size_align(1, self.layout.align()).unwrap()
+        } else {
+            self.layout
+        };
+        // SAFETY: Invariant, `self.ptr` points to memory allocated with `self.layout`.
+        unsafe { alloc::dealloc(self.ptr, alloc_layout) }
     }
 }
 
@@ -56,27 +60,25 @@ impl std::ops::DerefMut for MiriAllocBytes {
 }
 
 impl MiriAllocBytes {
-    /// This method factors out how a `MiriAllocBytes` object is allocated,
-    /// specifically given an allocation function `alloc_fn`.
-    /// `alloc_fn` is only used if `size != 0`.
-    /// Returns `Err(layout)` if the allocation function returns a `ptr` that is `ptr.is_null()`.
+    /// This method factors out how a `MiriAllocBytes` object is allocated, given a specific allocation function.
+    /// If `size == 0` we allocate using a different `alloc_layout` with `size = 1`, to ensure each allocation has a unique address.
+    /// Returns `Err(alloc_layout)` if the allocation function returns a `ptr` where `ptr.is_null()`.
     fn alloc_with(
         size: usize,
         align: usize,
         alloc_fn: impl FnOnce(Layout) -> *mut u8,
     ) -> Result<MiriAllocBytes, Layout> {
         let layout = Layout::from_size_align(size, align).unwrap();
-        let ptr = if size == 0 {
-            std::ptr::without_provenance_mut(align)
+        // When size is 0 we allocate 1 byte anyway, to ensure each allocation has a unique address.
+        let alloc_layout =
+            if size == 0 { Layout::from_size_align(1, align).unwrap() } else { layout };
+        let ptr = alloc_fn(alloc_layout);
+        if ptr.is_null() {
+            Err(alloc_layout)
         } else {
-            let ptr = alloc_fn(layout);
-            if ptr.is_null() {
-                return Err(layout);
-            }
-            ptr
-        };
-        // SAFETY: All `MiriAllocBytes` invariants are fulfilled.
-        Ok(Self { ptr, layout })
+            // SAFETY: All `MiriAllocBytes` invariants are fulfilled.
+            Ok(Self { ptr, layout })
+        }
     }
 }
 
@@ -85,7 +87,7 @@ impl AllocBytes for MiriAllocBytes {
         let slice = slice.into();
         let size = slice.len();
         let align = align.bytes_usize();
-        // SAFETY: `alloc_fn` will only be used if `size != 0`.
+        // SAFETY: `alloc_fn` will only be used with `size != 0`.
         let alloc_fn = |layout| unsafe { alloc::alloc(layout) };
         let alloc_bytes = MiriAllocBytes::alloc_with(size, align, alloc_fn)
             .unwrap_or_else(|layout| alloc::handle_alloc_error(layout));
@@ -98,7 +100,7 @@ impl AllocBytes for MiriAllocBytes {
     fn zeroed(size: Size, align: Align) -> Option<Self> {
         let size = size.bytes_usize();
         let align = align.bytes_usize();
-        // SAFETY: `alloc_fn` will only be used if `size != 0`.
+        // SAFETY: `alloc_fn` will only be used with `size != 0`.
         let alloc_fn = |layout| unsafe { alloc::alloc_zeroed(layout) };
         MiriAllocBytes::alloc_with(size, align, alloc_fn).ok()
     }

src/tools/miri/src/borrow_tracker/tree_borrows/perms.rs

@@ -17,6 +17,7 @@ enum PermissionPriv {
     /// is relevant
     /// - `conflicted` is set on foreign reads,
     /// - `conflicted` must not be set on child writes (there is UB otherwise).
+    ///
     /// This is so that the behavior of `Reserved` adheres to the rules of `noalias`:
     /// - foreign-read then child-write is UB due to `conflicted`,
     /// - child-write then foreign-read is UB since child-write will activate and then
@@ -339,15 +340,15 @@ pub mod diagnostics {
         /// This function assumes that its arguments apply to the same location
         /// and that they were obtained during a normal execution. It will panic otherwise.
         /// - all transitions involved in `self` and `err` should be increasing
-        /// (Reserved < Active < Frozen < Disabled);
+        ///   (Reserved < Active < Frozen < Disabled);
         /// - between `self` and `err` the permission should also be increasing,
-        /// so all permissions inside `err` should be greater than `self.1`;
+        ///   so all permissions inside `err` should be greater than `self.1`;
         /// - `Active` and `Reserved(conflicted=false)` cannot cause an error
-        /// due to insufficient permissions, so `err` cannot be a `ChildAccessForbidden(_)`
-        /// of either of them;
+        ///   due to insufficient permissions, so `err` cannot be a `ChildAccessForbidden(_)`
+        ///   of either of them;
         /// - `err` should not be `ProtectedDisabled(Disabled)`, because the protected
-        /// tag should not have been `Disabled` in the first place (if this occurs it means
-        /// we have unprotected tags that become protected)
+        ///   tag should not have been `Disabled` in the first place (if this occurs it means
+        ///   we have unprotected tags that become protected)
         pub(in super::super) fn is_relevant(&self, err: TransitionError) -> bool {
             // NOTE: `super::super` is the visibility of `TransitionError`
             assert!(self.is_possible());

src/tools/miri/src/borrow_tracker/tree_borrows/tree/tests.rs

@@ -230,6 +230,7 @@ mod spurious_read {
     /// - any access to the same location
     /// - end of one of them being protected
     /// - a retag that would change their relative position
+    ///
     /// The type `TestEvent` models these kinds of events.
     ///
     /// In order to prevent `x` or `y` from losing their protector,