Miri subtree update

Cargo.lock

@@ -2326,7 +2326,6 @@ dependencies = [
  "tempfile",
  "tikv-jemalloc-sys",
  "ui_test",
- "windows-sys 0.59.0",
 ]
 
 [[package]]

src/tools/miri/Cargo.lock

@@ -555,7 +555,6 @@ dependencies = [
  "tempfile",
  "tikv-jemalloc-sys",
  "ui_test",
- "windows-sys",
 ]
 
 [[package]]

src/tools/miri/Cargo.toml

@@ -40,13 +40,6 @@ libc = "0.2"
 libffi = "4.0.0"
 libloading = "0.8"
 
-[target.'cfg(target_family = "windows")'.dependencies]
-windows-sys = { version = "0.59", features = [
-    "Win32_Foundation",
-    "Win32_System_IO",
-    "Win32_Storage_FileSystem",
-] }
-
 [dev-dependencies]
 ui_test = "0.29.1"
 colored = "2"

src/tools/miri/README.md

@@ -398,9 +398,11 @@ to Miri failing to detect cases of undefined behavior in a program.
   **unsound** since the fallback body might not be checking for all UB.
 * `-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.
+  Unix systems. Functions not provided by that file are still executed via the usual Miri shims. If
+  a path to a directory is specified, all files in that directory are included nonrecursively. This
+  flag can be passed multiple times to specify multiple files and/or directories.
   **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.
+  Miri itself! And of course, Miri often 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
@@ -458,6 +460,10 @@ to Miri failing to detect cases of undefined behavior in a program.
   This is much less likely with Stacked Borrows.
   Using Tree Borrows currently implies `-Zmiri-strict-provenance` because integer-to-pointer
   casts are not supported in this mode, but that may change in the future.
+* `-Zmiri-tree-borrows-no-precise-interior-mut` makes Tree Borrows
+  track interior mutable data on the level of references instead of on the
+  byte-level as is done by default.  Therefore, with this flag, Tree
+  Borrows will be more permissive.
 * `-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.
 

src/tools/miri/rust-version

@@ -1 +1 @@
-337c11e5932275e7d450c1f2e26f289f0ddfa717
+c31cccb7b5cc098b1a8c1794ed38d7fdbec0ccb0

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

@@ -132,7 +132,7 @@ trait EvalContextExtPriv<'tcx>: crate::MiriInterpCxExt<'tcx> {
         assert!(!matches!(info.kind, AllocKind::Dead));
 
         // This allocation does not have a base address yet, pick or reuse one.
-        if this.machine.native_lib.is_some() {
+        if !this.machine.native_lib.is_empty() {
             // In native lib mode, we use the "real" address of the bytes for this allocation.
             // This ensures the interpreted program and native code have the same view of memory.
             let params = this.machine.get_default_alloc_params();
@@ -413,7 +413,7 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
     ) -> InterpResult<'tcx, MiriAllocBytes> {
         let this = self.eval_context_ref();
         assert!(this.tcx.try_get_global_alloc(id).is_some());
-        if this.machine.native_lib.is_some() {
+        if !this.machine.native_lib.is_empty() {
             // In native lib mode, MiriAllocBytes for global allocations are handled via `prepared_alloc_bytes`.
             // This additional call ensures that some `MiriAllocBytes` are always prepared, just in case
             // this function gets called before the first time `addr_from_alloc_id` gets called.

src/tools/miri/src/bin/miri.rs

@@ -35,7 +35,7 @@ use std::sync::{Arc, Once};
 
 use miri::{
     BacktraceStyle, BorrowTrackerMethod, GenmcConfig, GenmcCtx, MiriConfig, MiriEntryFnType,
-    ProvenanceMode, RetagFields, ValidationMode,
+    ProvenanceMode, RetagFields, TreeBorrowsParams, ValidationMode,
 };
 use rustc_abi::ExternAbi;
 use rustc_data_structures::sync;
@@ -554,8 +554,21 @@ fn main() {
         } else if arg == "-Zmiri-disable-stacked-borrows" {
             miri_config.borrow_tracker = None;
         } else if arg == "-Zmiri-tree-borrows" {
-            miri_config.borrow_tracker = Some(BorrowTrackerMethod::TreeBorrows);
+            miri_config.borrow_tracker =
+                Some(BorrowTrackerMethod::TreeBorrows(TreeBorrowsParams {
+                    precise_interior_mut: true,
+                }));
             miri_config.provenance_mode = ProvenanceMode::Strict;
+        } else if arg == "-Zmiri-tree-borrows-no-precise-interior-mut" {
+            match &mut miri_config.borrow_tracker {
+                Some(BorrowTrackerMethod::TreeBorrows(params)) => {
+                    params.precise_interior_mut = false;
+                }
+                _ =>
+                    show_error!(
+                        "`-Zmiri-tree-borrows` is required before `-Zmiri-tree-borrows-no-precise-interior-mut`"
+                    ),
+            };
         } else if arg == "-Zmiri-disable-data-race-detector" {
             miri_config.data_race_detector = false;
             miri_config.weak_memory_emulation = false;
@@ -692,11 +705,18 @@ fn main() {
             };
         } else if let Some(param) = arg.strip_prefix("-Zmiri-native-lib=") {
             let filename = param.to_string();
-            if std::path::Path::new(&filename).exists() {
-                if let Some(other_filename) = miri_config.native_lib {
-                    show_error!("-Zmiri-native-lib is already set to {}", other_filename.display());
+            let file_path = std::path::Path::new(&filename);
+            if file_path.exists() {
+                // For directories, nonrecursively add all normal files inside
+                if let Ok(dir) = file_path.read_dir() {
+                    for lib in dir.filter_map(|res| res.ok()) {
+                        if lib.file_type().unwrap().is_file() {
+                            miri_config.native_lib.push(lib.path().to_owned());
+                        }
+                    }
+                } else {
+                    miri_config.native_lib.push(filename.into());
                 }
-                miri_config.native_lib = Some(filename.into());
             } else {
                 show_error!("-Zmiri-native-lib `{}` does not exist", filename);
             }
@@ -725,18 +745,19 @@ fn main() {
         }
     }
     // Tree Borrows implies strict provenance, and is not compatible with native calls.
-    if matches!(miri_config.borrow_tracker, Some(BorrowTrackerMethod::TreeBorrows)) {
+    if matches!(miri_config.borrow_tracker, Some(BorrowTrackerMethod::TreeBorrows { .. })) {
         if miri_config.provenance_mode != ProvenanceMode::Strict {
             show_error!(
                 "Tree Borrows does not support integer-to-pointer casts, and hence requires strict provenance"
             );
         }
-        if miri_config.native_lib.is_some() {
+        if !miri_config.native_lib.is_empty() {
             show_error!("Tree Borrows is not compatible with calling native functions");
         }
     }
+
     // Native calls and strict provenance are not compatible.
-    if miri_config.native_lib.is_some() && miri_config.provenance_mode == ProvenanceMode::Strict {
+    if !miri_config.native_lib.is_empty() && miri_config.provenance_mode == ProvenanceMode::Strict {
         show_error!("strict provenance is not compatible with calling native functions");
     }
     // You can set either one seed or many.

src/tools/miri/src/borrow_tracker/mod.rs

@@ -226,7 +226,13 @@ pub enum BorrowTrackerMethod {
     /// Stacked Borrows, as implemented in borrow_tracker/stacked_borrows
     StackedBorrows,
     /// Tree borrows, as implemented in borrow_tracker/tree_borrows
-    TreeBorrows,
+    TreeBorrows(TreeBorrowsParams),
+}
+
+/// Parameters that Tree Borrows can take.
+#[derive(Debug, Copy, Clone, PartialEq, Eq)]
+pub struct TreeBorrowsParams {
+    pub precise_interior_mut: bool,
 }
 
 impl BorrowTrackerMethod {
@@ -237,6 +243,13 @@ impl BorrowTrackerMethod {
             config.retag_fields,
         ))
     }
+
+    pub fn get_tree_borrows_params(self) -> TreeBorrowsParams {
+        match self {
+            BorrowTrackerMethod::TreeBorrows(params) => params,
+            _ => panic!("can only be called when `BorrowTrackerMethod` is `TreeBorrows`"),
+        }
+    }
 }
 
 impl GlobalStateInner {
@@ -252,7 +265,7 @@ impl GlobalStateInner {
                 AllocState::StackedBorrows(Box::new(RefCell::new(Stacks::new_allocation(
                     id, alloc_size, self, kind, machine,
                 )))),
-            BorrowTrackerMethod::TreeBorrows =>
+            BorrowTrackerMethod::TreeBorrows { .. } =>
                 AllocState::TreeBorrows(Box::new(RefCell::new(Tree::new_allocation(
                     id, alloc_size, self, kind, machine,
                 )))),
@@ -271,7 +284,7 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
         let method = this.machine.borrow_tracker.as_ref().unwrap().borrow().borrow_tracker_method;
         match method {
             BorrowTrackerMethod::StackedBorrows => this.sb_retag_ptr_value(kind, val),
-            BorrowTrackerMethod::TreeBorrows => this.tb_retag_ptr_value(kind, val),
+            BorrowTrackerMethod::TreeBorrows { .. } => this.tb_retag_ptr_value(kind, val),
         }
     }
 
@@ -284,7 +297,7 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
         let method = this.machine.borrow_tracker.as_ref().unwrap().borrow().borrow_tracker_method;
         match method {
             BorrowTrackerMethod::StackedBorrows => this.sb_retag_place_contents(kind, place),
-            BorrowTrackerMethod::TreeBorrows => this.tb_retag_place_contents(kind, place),
+            BorrowTrackerMethod::TreeBorrows { .. } => this.tb_retag_place_contents(kind, place),
         }
     }
 
@@ -293,7 +306,7 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
         let method = this.machine.borrow_tracker.as_ref().unwrap().borrow().borrow_tracker_method;
         match method {
             BorrowTrackerMethod::StackedBorrows => this.sb_protect_place(place),
-            BorrowTrackerMethod::TreeBorrows => this.tb_protect_place(place),
+            BorrowTrackerMethod::TreeBorrows { .. } => this.tb_protect_place(place),
         }
     }
 
@@ -302,7 +315,7 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
         let method = this.machine.borrow_tracker.as_ref().unwrap().borrow().borrow_tracker_method;
         match method {
             BorrowTrackerMethod::StackedBorrows => this.sb_expose_tag(alloc_id, tag),
-            BorrowTrackerMethod::TreeBorrows => this.tb_expose_tag(alloc_id, tag),
+            BorrowTrackerMethod::TreeBorrows { .. } => this.tb_expose_tag(alloc_id, tag),
         }
     }
 
@@ -319,7 +332,7 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
                 this.tcx.tcx.dcx().warn("Stacked Borrows does not support named pointers; `miri_pointer_name` is a no-op");
                 interp_ok(())
             }
-            BorrowTrackerMethod::TreeBorrows =>
+            BorrowTrackerMethod::TreeBorrows { .. } =>
                 this.tb_give_pointer_debug_name(ptr, nth_parent, name),
         }
     }
@@ -333,7 +346,7 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
         let method = borrow_tracker.borrow().borrow_tracker_method;
         match method {
             BorrowTrackerMethod::StackedBorrows => this.print_stacks(alloc_id),
-            BorrowTrackerMethod::TreeBorrows => this.print_tree(alloc_id, show_unnamed),
+            BorrowTrackerMethod::TreeBorrows { .. } => this.print_tree(alloc_id, show_unnamed),
         }
     }
 

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

@@ -312,8 +312,6 @@ trait EvalContextPrivExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
         }
 
         let span = this.machine.current_span();
-        let alloc_extra = this.get_alloc_extra(alloc_id)?;
-        let mut tree_borrows = alloc_extra.borrow_tracker_tb().borrow_mut();
 
         // Store initial permissions and their corresponding range.
         let mut perms_map: RangeMap<LocationState> = RangeMap::new(
@@ -342,36 +340,83 @@ trait EvalContextPrivExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
         assert!(new_perm.freeze_access);
 
         let protected = new_perm.protector.is_some();
-        this.visit_freeze_sensitive(place, ptr_size, |range, frozen| {
-            has_unsafe_cell = has_unsafe_cell || !frozen;
-
-            // We are only ever `Frozen` inside the frozen bits.
-            let (perm, access) = if frozen {
+        let precise_interior_mut = this
+            .machine
+            .borrow_tracker
+            .as_mut()
+            .unwrap()
+            .get_mut()
+            .borrow_tracker_method
+            .get_tree_borrows_params()
+            .precise_interior_mut;
+
+        let default_perm = if !precise_interior_mut {
+            // NOTE: Using `ty_is_freeze` doesn't give the same result as going through the range
+            // and computing `has_unsafe_cell`.  This is because of zero-sized `UnsafeCell`, for which
+            // `has_unsafe_cell` is false, but `!ty_is_freeze` is true.
+            let ty_is_freeze = place.layout.ty.is_freeze(*this.tcx, this.typing_env());
+            let (perm, access) = if ty_is_freeze {
                 (new_perm.freeze_perm, new_perm.freeze_access)
             } else {
                 (new_perm.nonfreeze_perm, new_perm.nonfreeze_access)
             };
+            let sifa = perm.strongest_idempotent_foreign_access(protected);
+            let new_loc = if access {
+                LocationState::new_accessed(perm, sifa)
+            } else {
+                LocationState::new_non_accessed(perm, sifa)
+            };
+
+            for (_loc_range, loc) in perms_map.iter_mut_all() {
+                *loc = new_loc;
+            }
+
+            perm
+        } else {
+            this.visit_freeze_sensitive(place, ptr_size, |range, frozen| {
+                has_unsafe_cell = has_unsafe_cell || !frozen;
 
-            // Store initial permissions.
-            for (_loc_range, loc) in perms_map.iter_mut(range.start, range.size) {
+                // We are only ever `Frozen` inside the frozen bits.
+                let (perm, access) = if frozen {
+                    (new_perm.freeze_perm, new_perm.freeze_access)
+                } else {
+                    (new_perm.nonfreeze_perm, new_perm.nonfreeze_access)
+                };
                 let sifa = perm.strongest_idempotent_foreign_access(protected);
                 // NOTE: Currently, `access` is false if and only if `perm` is Cell, so this `if`
                 // doesn't not change whether any code is UB or not. We could just always use
                 // `new_accessed` and everything would stay the same. But that seems conceptually
                 // odd, so we keep the initial "accessed" bit of the `LocationState` in sync with whether
                 // a read access is performed below.
-                if access {
-                    *loc = LocationState::new_accessed(perm, sifa);
+                let new_loc = if access {
+                    LocationState::new_accessed(perm, sifa)
                 } else {
-                    *loc = LocationState::new_non_accessed(perm, sifa);
+                    LocationState::new_non_accessed(perm, sifa)
+                };
+
+                // Store initial permissions.
+                for (_loc_range, loc) in perms_map.iter_mut(range.start, range.size) {
+                    *loc = new_loc;
                 }
-            }
 
-            // Some reborrows incur a read access to the parent.
-            if access {
+                interp_ok(())
+            })?;
+
+            // Allow lazily writing to surrounding data if we found an `UnsafeCell`.
+            if has_unsafe_cell { new_perm.nonfreeze_perm } else { new_perm.freeze_perm }
+        };
+
+        let alloc_extra = this.get_alloc_extra(alloc_id)?;
+        let mut tree_borrows = alloc_extra.borrow_tracker_tb().borrow_mut();
+
+        for (perm_range, perm) in perms_map.iter_mut_all() {
+            if perm.is_accessed() {
+                // Some reborrows incur a read access to the parent.
                 // Adjust range to be relative to allocation start (rather than to `place`).
-                let mut range_in_alloc = range;
-                range_in_alloc.start += base_offset;
+                let range_in_alloc = AllocRange {
+                    start: Size::from_bytes(perm_range.start) + base_offset,
+                    size: Size::from_bytes(perm_range.end - perm_range.start),
+                };
 
                 tree_borrows.perform_access(
                     orig_tag,
@@ -382,7 +427,7 @@ trait EvalContextPrivExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
                 )?;
 
                 // Also inform the data race model (but only if any bytes are actually affected).
-                if range.size.bytes() > 0 {
+                if range_in_alloc.size.bytes() > 0 {
                     if let Some(data_race) = alloc_extra.data_race.as_vclocks_ref() {
                         data_race.read(
                             alloc_id,
@@ -394,17 +439,15 @@ trait EvalContextPrivExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
                     }
                 }
             }
-            interp_ok(())
-        })?;
+        }
 
         // Record the parent-child pair in the tree.
         tree_borrows.new_child(
             base_offset,
             orig_tag,
             new_tag,
             perms_map,
-            // Allow lazily writing to surrounding data if we found an `UnsafeCell`.
-            if has_unsafe_cell { new_perm.nonfreeze_perm } else { new_perm.freeze_perm },
+            default_perm,
             protected,
             span,
         )?;

src/tools/miri/src/diagnostics.rs

@@ -682,7 +682,10 @@ impl<'tcx> MiriMachine<'tcx> {
                     ),
                 ];
                 if self.borrow_tracker.as_ref().is_some_and(|b| {
-                    matches!(b.borrow().borrow_tracker_method(), BorrowTrackerMethod::TreeBorrows)
+                    matches!(
+                        b.borrow().borrow_tracker_method(),
+                        BorrowTrackerMethod::TreeBorrows { .. }
+                    )
                 }) {
                     v.push(
                         note!("Tree Borrows does not support integer-to-pointer casts, so the program is likely to go wrong when this pointer gets used")