fix handling of scalars in futex code

Author: joboet

src/lib.rs

@@ -15,6 +15,7 @@
 #![feature(unqualified_local_imports)]
 #![feature(derive_coerce_pointee)]
 #![feature(arbitrary_self_types)]
+#![feature(unsigned_is_multiple_of)]
 // Configure clippy and other lints
 #![allow(
     clippy::collapsible_else_if,

src/shims/unix/linux_like/sync.rs

@@ -169,7 +169,7 @@ pub fn futex<'tcx>(
                         }
                         |ecx, unblock: UnblockKind| match unblock {
                             UnblockKind::Ready => {
-                                ecx.write_scalar(Scalar::from_target_isize(0, ecx), &dest)
+                                ecx.write_int(0, &dest)
                             }
                             UnblockKind::TimedOut => {
                                 ecx.set_last_error_and_return(LibcError("ETIMEDOUT"), &dest)

src/shims/unix/macos/sync.rs

@@ -120,8 +120,8 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
         // Perform validation of the arguments.
         let addr = ptr.addr().bytes();
         if addr == 0
-            || addr % size != 0
             || !matches!(size, 4 | 8)
+            || !addr.is_multiple_of(size)
             || (flags != none && flags != shared)
             || clock_timeout
                 .is_some_and(|(clock, _, timeout)| clock != absolute_clock || timeout == 0)
@@ -164,7 +164,7 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
             return interp_ok(());
         }
 
-        if futex_val == value as u128 {
+        if futex_val == value.into() {
             // If the values are the same, we have to block.
             let futex_ref = futex.futex.clone();
             let dest = dest.clone();
@@ -180,8 +180,8 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
                     |this, unblock: UnblockKind| {
                         match unblock {
                             UnblockKind::Ready => {
-                                let remaining = futex_ref.waiters();
-                                this.write_scalar(Scalar::from_i32(remaining as i32), &dest)
+                                let remaining = futex_ref.waiters().try_into().unwrap();
+                                this.write_scalar(Scalar::from_i32(remaining), &dest)
                             }
                             UnblockKind::TimedOut => {
                                 this.set_last_error_and_return(LibcError("ETIMEDOUT"), &dest)
@@ -192,7 +192,7 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
             );
         } else {
             // else retrieve the current number of waiters.
-            let waiters = futex.futex.waiters() as i32;
+            let waiters = futex.futex.waiters().try_into().unwrap();
             this.write_scalar(Scalar::from_i32(waiters), dest)?;
         }
 

src/shims/windows/sync.rs

@@ -224,11 +224,11 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
                     |this, unblock: UnblockKind| {
                         match unblock {
                             UnblockKind::Ready => {
-                                this.write_scalar(Scalar::from_i32(1), &dest)
+                                this.write_int(1, &dest)
                             }
                             UnblockKind::TimedOut => {
                                 this.set_last_error(IoError::WindowsError("ERROR_TIMEOUT"))?;
-                                this.write_scalar(Scalar::from_i32(0), &dest)
+                                this.write_int(0, &dest)
                             }
                         }
                     }