libc_current_sigrtmax stub

src/shims/unix/foreign_items.rs

@@ -83,6 +83,13 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
                 let result = this.socketpair(domain, type_, protocol, sv)?;
                 this.write_scalar(Scalar::from_i32(result), dest)?;
             }
+            "__libc_current_sigrtmax" => {
+                // TODO this function takes `void`. does anything go in this let?
+                let [] = this.check_shim(abi, Abi::C {unwind: false}, link_name, args)?;
+
+                let result = this.libc_current_sigrtmax()?;
+                this.write_scalar(Scalar::from_i32(result), dest)?;
+            }
             "close" => {
                 let [fd] = this.check_shim(abi, Abi::C { unwind: false }, link_name, args)?;
                 let result = this.close(fd)?;

src/shims/unix/fs.rs

@@ -793,6 +793,13 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
         Ok(0)
     }
 
+    fn libc_current_sigrtmax(&mut self) -> InterpResult<'tcx, i32> {
+        let _this = self.eval_context_mut();
+
+        // TODO return the correct value
+        Ok(42)
+    }
+
     fn read(
         &mut self,
         fd: i32,

tests/fail/crates/tokio_mvp.rs

@@ -1,5 +1,5 @@
 //@compile-flags: -Zmiri-disable-isolation
-//@error-pattern: unsupported operation: can't call foreign function: __libc_current_sigrtmax
+//@error-pattern: unsupported operation: cannot close epoll
 //@normalize-stderr-test: "   = note: inside .*\n" -> ""
 //@only-target-linux: the errors differ too much between platforms
 

tests/fail/crates/tokio_mvp.stderr

@@ -1,19 +1,45 @@
-error: unsupported operation: can't call foreign function: __libc_current_sigrtmax
-  --> CARGO_REGISTRY/.../mod.rs:LL:CC
+warning: integer-to-pointer cast
+  --> CARGO_REGISTRY/.../imp_std.rs:LL:CC
    |
-LL |         unsafe { __libc_current_sigrtmax() }
-   |                  ^^^^^^^^^^^^^^^^^^^^^^^^^ can't call foreign function: __libc_current_sigrtmax
+LL |             let mut waiter = (queue & !STATE_MASK) as *const Waiter;
+   |                              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ integer-to-pointer cast
    |
-   = help: this is likely not a bug in the program; it indicates that the program performed an operation that the interpreter does not support
-   = note: BACKTRACE:
+   = help: This program is using integer-to-pointer casts or (equivalently) `ptr::from_exposed_addr`,
+   = help: which means that Miri might miss pointer bugs in this program.
+   = help: See https://doc.rust-lang.org/nightly/std/ptr/fn.from_exposed_addr.html for more details on that operation.
+   = help: To ensure that Miri does not miss bugs in your program, use Strict Provenance APIs (https://doc.rust-lang.org/nightly/std/ptr/index.html#strict-provenance, https://crates.io/crates/sptr) instead.
+   = help: You can then pass the `-Zmiri-strict-provenance` flag to Miri, to ensure you are not relying on `from_exposed_addr` semantics.
+   = help: Alternatively, the `-Zmiri-permissive-provenance` flag disables this warning.
+   = note: backtrace:
 note: inside `main` at $DIR/tokio_mvp.rs:LL:CC
   --> $DIR/tokio_mvp.rs:LL:CC
    |
 LL | #[tokio::main]
    | ^^^^^^^^^^^^^^
-   = note: this error originates in the attribute macro `tokio::main` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this warning originates in the attribute macro `tokio::main` (in Nightly builds, run with -Z macro-backtrace for more info)
 
-note: some details are omitted, run with `MIRIFLAGS=-Zmiri-backtrace=full` for a verbose backtrace
+warning: integer-to-pointer cast
+  --> CARGO_REGISTRY/.../word_lock.rs:LL:CC
+   |
+LL |         (self & QUEUE_MASK) as *const ThreadData
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ integer-to-pointer cast
+   |
+note: inside `main` at $DIR/tokio_mvp.rs:LL:CC
+  --> $DIR/tokio_mvp.rs:LL:CC
+   |
+LL | #[tokio::main]
+   |              ^
+   = note: this warning originates in the attribute macro `tokio::main` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: unsupported operation: cannot close epoll
+  --> CARGO_REGISTRY/.../epoll.rs:LL:CC
+   |
+LL |         if let Err(err) = syscall!(close(self.ep)) {
+   |                           ^^^^^^^^^^^^^^^^^^^^^^^^ cannot close epoll
+   |
+   = help: this is likely not a bug in the program; it indicates that the program performed an operation that the interpreter does not support
+   = note: backtrace:
+   = note: this error originates in the macro `syscall` (in Nightly builds, run with -Z macro-backtrace for more info)
 
-error: aborting due to previous error
+error: aborting due to previous error; 2 warnings emitted