Rollup merge of #140521 - RalfJung:oob-error, r=saethlin

interpret: better error message for out-of-bounds pointer arithmetic and accesses

Fixes rust-lang/rust#93881
r? `@saethlin`

Author: matthiaskrgr

src/borrow_tracker/stacked_borrows/mod.rs

@@ -594,7 +594,7 @@ trait EvalContextPrivExt<'tcx, 'ecx>: crate::MiriInterpCxExt<'tcx> {
     ) -> InterpResult<'tcx, Option<Provenance>> {
         let this = self.eval_context_mut();
         // Ensure we bail out if the pointer goes out-of-bounds (see miri#1050).
-        this.check_ptr_access(place.ptr(), size, CheckInAllocMsg::InboundsTest)?;
+        this.check_ptr_access(place.ptr(), size, CheckInAllocMsg::Dereferenceable)?;
 
         // It is crucial that this gets called on all code paths, to ensure we track tag creation.
         let log_creation = |this: &MiriInterpCx<'tcx>,

src/borrow_tracker/tree_borrows/mod.rs

@@ -197,7 +197,7 @@ trait EvalContextPrivExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
         // Make sure the new permission makes sense as the initial permission of a fresh tag.
         assert!(new_perm.initial_state.is_initial());
         // Ensure we bail out if the pointer goes out-of-bounds (see miri#1050).
-        this.check_ptr_access(place.ptr(), ptr_size, CheckInAllocMsg::InboundsTest)?;
+        this.check_ptr_access(place.ptr(), ptr_size, CheckInAllocMsg::Dereferenceable)?;
 
         // It is crucial that this gets called on all code paths, to ensure we track tag creation.
         let log_creation = |this: &MiriInterpCx<'tcx>,

src/shims/unix/android/thread.rs

@@ -42,7 +42,7 @@ pub fn prctl<'tcx>(
             ecx.check_ptr_access(
                 name.to_pointer(ecx)?,
                 Size::from_bytes(TASK_COMM_LEN),
-                CheckInAllocMsg::MemoryAccessTest,
+                CheckInAllocMsg::MemoryAccess,
             )?;
             let res = ecx.pthread_getname_np(thread, name, len, /* truncate*/ false)?;
             assert_eq!(res, ThreadNameResult::Ok);

src/shims/unix/fd.rs

@@ -226,7 +226,7 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
         trace!("Reading from FD {}, size {}", fd_num, count);
 
         // Check that the *entire* buffer is actually valid memory.
-        this.check_ptr_access(buf, Size::from_bytes(count), CheckInAllocMsg::MemoryAccessTest)?;
+        this.check_ptr_access(buf, Size::from_bytes(count), CheckInAllocMsg::MemoryAccess)?;
 
         // We cap the number of read bytes to the largest value that we are able to fit in both the
         // host's and target's `isize`. This saves us from having to handle overflows later.
@@ -292,7 +292,7 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
         // Isolation check is done via `FileDescription` trait.
 
         // Check that the *entire* buffer is actually valid memory.
-        this.check_ptr_access(buf, Size::from_bytes(count), CheckInAllocMsg::MemoryAccessTest)?;
+        this.check_ptr_access(buf, Size::from_bytes(count), CheckInAllocMsg::MemoryAccess)?;
 
         // We cap the number of written bytes to the largest value that we are able to fit in both the
         // host's and target's `isize`. This saves us from having to handle overflows later.

tests/fail-dep/libc/affinity.stderr

@@ -1,8 +1,8 @@
-error: Undefined Behavior: memory access failed: expected a pointer to 129 bytes of memory, but got ALLOC which is only 128 bytes from the end of the allocation
+error: Undefined Behavior: memory access failed: attempting to access 129 bytes, but got ALLOC which is only 128 bytes from the end of the allocation
   --> tests/fail-dep/libc/affinity.rs:LL:CC
    |
 LL |     let err = unsafe { sched_setaffinity(PID, size_of::<cpu_set_t>() + 1, &cpuset) };
-   |                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ memory access failed: expected a pointer to 129 bytes of memory, but got ALLOC which is only 128 bytes from the end of the allocation
+   |                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ memory access failed: attempting to access 129 bytes, but got ALLOC which is only 128 bytes from the end of the allocation
    |
    = 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

tests/fail-dep/libc/memchr_null.stderr

@@ -1,8 +1,8 @@
-error: Undefined Behavior: out-of-bounds pointer use: expected a pointer to some allocation, but got a null pointer
+error: Undefined Behavior: pointer not dereferenceable: pointer must point to some allocation, but got null pointer
   --> tests/fail-dep/libc/memchr_null.rs:LL:CC
    |
 LL |         libc::memchr(ptr::null(), 0, 0);
-   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ out-of-bounds pointer use: expected a pointer to some allocation, but got a null pointer
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ pointer not dereferenceable: pointer must point to some allocation, but got null pointer
    |
    = 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

tests/fail-dep/libc/memcmp_null.stderr

@@ -1,8 +1,8 @@
-error: Undefined Behavior: out-of-bounds pointer use: expected a pointer to some allocation, but got a null pointer
+error: Undefined Behavior: pointer not dereferenceable: pointer must point to some allocation, but got null pointer
   --> tests/fail-dep/libc/memcmp_null.rs:LL:CC
    |
 LL |         libc::memcmp(ptr::null(), ptr::null(), 0);
-   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ out-of-bounds pointer use: expected a pointer to some allocation, but got a null pointer
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ pointer not dereferenceable: pointer must point to some allocation, but got null pointer
    |
    = 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

tests/fail-dep/libc/memcmp_zero.stderr

@@ -1,8 +1,8 @@
-error: Undefined Behavior: out-of-bounds pointer use: expected a pointer to some allocation, but got 0x2a[noalloc] which is a dangling pointer (it has no provenance)
+error: Undefined Behavior: pointer not dereferenceable: pointer must point to some allocation, but got 0x2a[noalloc] which is a dangling pointer (it has no provenance)
   --> tests/fail-dep/libc/memcmp_zero.rs:LL:CC
    |
 LL |         libc::memcmp(ptr.cast(), ptr.cast(), 0);
-   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ out-of-bounds pointer use: expected a pointer to some allocation, but got 0x2a[noalloc] which is a dangling pointer (it has no provenance)
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ pointer not dereferenceable: pointer must point to some allocation, but got 0x2a[noalloc] which is a dangling pointer (it has no provenance)
    |
    = 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

tests/fail-dep/libc/memcpy_zero.stderr

@@ -1,8 +1,8 @@
-error: Undefined Behavior: out-of-bounds pointer use: expected a pointer to some allocation, but got 0x17[noalloc] which is a dangling pointer (it has no provenance)
+error: Undefined Behavior: pointer not dereferenceable: pointer must point to some allocation, but got 0x17[noalloc] which is a dangling pointer (it has no provenance)
   --> tests/fail-dep/libc/memcpy_zero.rs:LL:CC
    |
 LL |         libc::memcpy(to.cast(), from.cast(), 0);
-   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ out-of-bounds pointer use: expected a pointer to some allocation, but got 0x17[noalloc] which is a dangling pointer (it has no provenance)
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ pointer not dereferenceable: pointer must point to some allocation, but got 0x17[noalloc] which is a dangling pointer (it has no provenance)
    |
    = 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

tests/fail-dep/libc/memrchr_null.stderr

@@ -1,8 +1,8 @@
-error: Undefined Behavior: out-of-bounds pointer use: expected a pointer to some allocation, but got a null pointer
+error: Undefined Behavior: pointer not dereferenceable: pointer must point to some allocation, but got null pointer
   --> tests/fail-dep/libc/memrchr_null.rs:LL:CC
    |
 LL |         libc::memrchr(ptr::null(), 0, 0);
-   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ out-of-bounds pointer use: expected a pointer to some allocation, but got a null pointer
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ pointer not dereferenceable: pointer must point to some allocation, but got null pointer
    |
    = 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

tests/fail/both_borrows/issue-miri-1050-1.rs

@@ -1,6 +1,6 @@
 //@revisions: stack tree
 //@[tree]compile-flags: -Zmiri-tree-borrows
-//@error-in-other-file: expected a pointer to 4 bytes of memory
+//@error-in-other-file: pointer not dereferenceable
 
 fn main() {
     unsafe {

tests/fail/both_borrows/issue-miri-1050-1.stack.stderr

@@ -1,8 +1,8 @@
-error: Undefined Behavior: out-of-bounds pointer use: expected a pointer to 4 bytes of memory, but got ALLOC which is only 2 bytes from the end of the allocation
+error: Undefined Behavior: pointer not dereferenceable: pointer must be dereferenceable for 4 bytes, but got ALLOC which is only 2 bytes from the end of the allocation
   --> RUSTLIB/alloc/src/boxed.rs:LL:CC
    |
 LL |         Box(unsafe { Unique::new_unchecked(raw) }, alloc)
-   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ out-of-bounds pointer use: expected a pointer to 4 bytes of memory, but got ALLOC which is only 2 bytes from the end of the allocation
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ pointer not dereferenceable: pointer must be dereferenceable for 4 bytes, but got ALLOC which is only 2 bytes from the end of the allocation
    |
    = 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

tests/fail/both_borrows/issue-miri-1050-1.tree.stderr

@@ -1,8 +1,8 @@
-error: Undefined Behavior: out-of-bounds pointer use: expected a pointer to 4 bytes of memory, but got ALLOC which is only 2 bytes from the end of the allocation
+error: Undefined Behavior: pointer not dereferenceable: pointer must be dereferenceable for 4 bytes, but got ALLOC which is only 2 bytes from the end of the allocation
   --> RUSTLIB/alloc/src/boxed.rs:LL:CC
    |
 LL |         Box(unsafe { Unique::new_unchecked(raw) }, alloc)
-   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ out-of-bounds pointer use: expected a pointer to 4 bytes of memory, but got ALLOC which is only 2 bytes from the end of the allocation
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ pointer not dereferenceable: pointer must be dereferenceable for 4 bytes, but got ALLOC which is only 2 bytes from the end of the allocation
    |
    = 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

tests/fail/both_borrows/issue-miri-1050-2.stack.stderr

@@ -1,8 +1,8 @@
-error: Undefined Behavior: out-of-bounds pointer use: expected a pointer to 4 bytes of memory, but got 0x4[noalloc] which is a dangling pointer (it has no provenance)
+error: Undefined Behavior: pointer not dereferenceable: pointer must be dereferenceable for 4 bytes, but got 0x4[noalloc] which is a dangling pointer (it has no provenance)
   --> RUSTLIB/alloc/src/boxed.rs:LL:CC
    |
 LL |         Box(unsafe { Unique::new_unchecked(raw) }, alloc)
-   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ out-of-bounds pointer use: expected a pointer to 4 bytes of memory, but got 0x4[noalloc] which is a dangling pointer (it has no provenance)
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ pointer not dereferenceable: pointer must be dereferenceable for 4 bytes, but got 0x4[noalloc] which is a dangling pointer (it has no provenance)
    |
    = 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

tests/fail/both_borrows/issue-miri-1050-2.tree.stderr

@@ -1,8 +1,8 @@
-error: Undefined Behavior: out-of-bounds pointer use: expected a pointer to 4 bytes of memory, but got 0x4[noalloc] which is a dangling pointer (it has no provenance)
+error: Undefined Behavior: pointer not dereferenceable: pointer must be dereferenceable for 4 bytes, but got 0x4[noalloc] which is a dangling pointer (it has no provenance)
   --> RUSTLIB/alloc/src/boxed.rs:LL:CC
    |
 LL |         Box(unsafe { Unique::new_unchecked(raw) }, alloc)
-   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ out-of-bounds pointer use: expected a pointer to 4 bytes of memory, but got 0x4[noalloc] which is a dangling pointer (it has no provenance)
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ pointer not dereferenceable: pointer must be dereferenceable for 4 bytes, but got 0x4[noalloc] which is a dangling pointer (it has no provenance)
    |
    = 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

tests/fail/dangling_pointers/dangling_pointer_offset.rs

@@ -6,6 +6,6 @@ fn main() {
         let b = Box::new(42);
         &*b as *const i32
     };
-    let x = unsafe { p.offset(42) }; //~ ERROR: /out-of-bounds pointer arithmetic: .* has been freed/
+    let x = unsafe { p.offset(42) }; //~ ERROR: /in-bounds pointer arithmetic failed: .* has been freed/
     panic!("this should never print: {:?}", x);
 }

tests/fail/dangling_pointers/dangling_pointer_offset.stderr

@@ -1,8 +1,8 @@
-error: Undefined Behavior: out-of-bounds pointer arithmetic: ALLOC has been freed, so this pointer is dangling
+error: Undefined Behavior: in-bounds pointer arithmetic failed: ALLOC has been freed, so this pointer is dangling
   --> tests/fail/dangling_pointers/dangling_pointer_offset.rs:LL:CC
    |
 LL |     let x = unsafe { p.offset(42) };
-   |                      ^^^^^^^^^^^^ out-of-bounds pointer arithmetic: ALLOC has been freed, so this pointer is dangling
+   |                      ^^^^^^^^^^^^ in-bounds pointer arithmetic failed: ALLOC has been freed, so this pointer is dangling
    |
    = 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

tests/fail/dangling_pointers/dangling_pointer_project_underscore_let.rs

@@ -7,6 +7,6 @@ fn main() {
         &*b as *const i32 as *const (u8, u8, u8, u8)
     };
     unsafe {
-        let _ = (*p).1; //~ ERROR: out-of-bounds pointer arithmetic
+        let _ = (*p).1; //~ ERROR: in-bounds pointer arithmetic failed
     }
 }

tests/fail/dangling_pointers/dangling_pointer_project_underscore_let.stderr

@@ -1,8 +1,8 @@
-error: Undefined Behavior: out-of-bounds pointer arithmetic: ALLOC has been freed, so this pointer is dangling
+error: Undefined Behavior: in-bounds pointer arithmetic failed: ALLOC has been freed, so this pointer is dangling
   --> tests/fail/dangling_pointers/dangling_pointer_project_underscore_let.rs:LL:CC
    |
 LL |         let _ = (*p).1;
-   |                 ^^^^^^ out-of-bounds pointer arithmetic: ALLOC has been freed, so this pointer is dangling
+   |                 ^^^^^^ in-bounds pointer arithmetic failed: ALLOC has been freed, so this pointer is dangling
    |
    = 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

tests/fail/dangling_pointers/dangling_pointer_project_underscore_let_type_annotation.rs

@@ -7,6 +7,6 @@ fn main() {
         &*b as *const i32 as *const (u8, u8, u8, u8)
     };
     unsafe {
-        let _: u8 = (*p).1; //~ ERROR: out-of-bounds pointer arithmetic
+        let _: u8 = (*p).1; //~ ERROR: in-bounds pointer arithmetic failed
     }
 }

tests/fail/dangling_pointers/dangling_pointer_project_underscore_let_type_annotation.stderr

@@ -1,8 +1,8 @@
-error: Undefined Behavior: out-of-bounds pointer arithmetic: ALLOC has been freed, so this pointer is dangling
+error: Undefined Behavior: in-bounds pointer arithmetic failed: ALLOC has been freed, so this pointer is dangling
   --> tests/fail/dangling_pointers/dangling_pointer_project_underscore_let_type_annotation.rs:LL:CC
    |
 LL |         let _: u8 = (*p).1;
-   |                     ^^^^^^ out-of-bounds pointer arithmetic: ALLOC has been freed, so this pointer is dangling
+   |                     ^^^^^^ in-bounds pointer arithmetic failed: ALLOC has been freed, so this pointer is dangling
    |
    = 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

tests/fail/dangling_pointers/dangling_pointer_project_underscore_match.rs

@@ -8,7 +8,7 @@ fn main() {
     };
     unsafe {
         match (*p).1 {
-            //~^ ERROR: out-of-bounds pointer arithmetic
+            //~^ ERROR: in-bounds pointer arithmetic failed
             _ => {}
         }
     }

tests/fail/dangling_pointers/dangling_pointer_project_underscore_match.stderr

@@ -1,8 +1,8 @@
-error: Undefined Behavior: out-of-bounds pointer arithmetic: ALLOC has been freed, so this pointer is dangling
+error: Undefined Behavior: in-bounds pointer arithmetic failed: ALLOC has been freed, so this pointer is dangling
   --> tests/fail/dangling_pointers/dangling_pointer_project_underscore_match.rs:LL:CC
    |
 LL |         match (*p).1 {
-   |               ^^^^^^ out-of-bounds pointer arithmetic: ALLOC has been freed, so this pointer is dangling
+   |               ^^^^^^ in-bounds pointer arithmetic failed: ALLOC has been freed, so this pointer is dangling
    |
    = 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

tests/fail/dangling_pointers/dangling_pointer_to_raw_pointer.stderr

@@ -1,8 +1,8 @@
-error: Undefined Behavior: out-of-bounds pointer use: expected a pointer to 4 bytes of memory, but got 0x10[noalloc] which is a dangling pointer (it has no provenance)
+error: Undefined Behavior: pointer not dereferenceable: pointer must be dereferenceable for 4 bytes, but got 0x10[noalloc] which is a dangling pointer (it has no provenance)
   --> tests/fail/dangling_pointers/dangling_pointer_to_raw_pointer.rs:LL:CC
    |
 LL |     unsafe { &(*x).0 as *const i32 }
-   |              ^^^^^^^ out-of-bounds pointer use: expected a pointer to 4 bytes of memory, but got 0x10[noalloc] which is a dangling pointer (it has no provenance)
+   |              ^^^^^^^ pointer not dereferenceable: pointer must be dereferenceable for 4 bytes, but got 0x10[noalloc] which is a dangling pointer (it has no provenance)
    |
    = 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

tests/fail/dangling_pointers/deref-invalid-ptr.stderr

@@ -1,8 +1,8 @@
-error: Undefined Behavior: out-of-bounds pointer use: expected a pointer to 4 bytes of memory, but got 0x10[noalloc] which is a dangling pointer (it has no provenance)
+error: Undefined Behavior: pointer not dereferenceable: pointer must be dereferenceable for 4 bytes, but got 0x10[noalloc] which is a dangling pointer (it has no provenance)
   --> tests/fail/dangling_pointers/deref-invalid-ptr.rs:LL:CC
    |
 LL |     let _y = unsafe { &*x as *const u32 };
-   |                       ^^^ out-of-bounds pointer use: expected a pointer to 4 bytes of memory, but got 0x10[noalloc] which is a dangling pointer (it has no provenance)
+   |                       ^^^ pointer not dereferenceable: pointer must be dereferenceable for 4 bytes, but got 0x10[noalloc] which is a dangling pointer (it has no provenance)
    |
    = 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