WIP implement shim for epoll_ctl

src/shims/unix/foreign_items.rs

@@ -65,6 +65,11 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
                 let result = this.epoll_create1(flag)?;
                 this.write_scalar(Scalar::from_i32(result), dest)?;
             }
+            "epoll_ctl" => {
+                let [epfd, op, fd, event] = this.check_shim(abi, Abi::C { unwind: false }, link_name, args)?;
+                let result = this.epoll_ctl(epfd, op, fd, event)?;
+                this.write_scalar(Scalar::from_i32(result), dest)?;
+            }
             "eventfd" => {
                 let [initval, flag] = this.check_shim(abi, Abi::C {unwind: false }, link_name, args)?;
                 let result = this.eventfd(initval, flag)?;

src/shims/unix/fs.rs

@@ -778,6 +778,39 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
         Ok(fd)
     }
 
+    fn epoll_ctl(
+        &mut self,
+        _epfd: &OpTy<'tcx, Tag>,
+        op: &OpTy<'tcx, Tag>,
+        fd: &OpTy<'tcx, Tag>,
+        _event: &OpTy<'tcx, Tag>,
+    ) -> InterpResult<'tcx, i32> {
+        let this = self.eval_context_mut();
+
+        let values = this.read_scalar(op)?.to_i32()?;
+        let fd = this.read_scalar(fd)?.to_i32()?;
+
+        let epoll_ctl_add = this.eval_libc_i32("EPOLL_CTL_ADD")?;
+        let epoll_ctl_mod = this.eval_libc_i32("EPOLL_CTL_MOD")?;
+        let epoll_ctl_del = this.eval_libc_i32("EPOLL_CTL_DEL")?;
+
+        if values == epoll_ctl_add {
+            if let Some(_file_descriptor) = this.machine.file_handler.handles.get(&fd) {
+                return Ok(-1);
+            } else {
+                return this.handle_not_found();
+            }
+        } else if values == epoll_ctl_mod {
+        } else if values == epoll_ctl_del {
+        } else {
+            let einval = this.eval_libc("EINVAL")?;
+            this.set_last_error(einval)?;
+            return Ok(-1);
+        }
+
+        Ok(0)
+    }
+
     fn eventfd(
         &mut self,
         _initval: &OpTy<'tcx, Tag>,