Add support for panicking in the emulated application when unsupported syscalls are encountered

Author: landaire

src/bin/miri.rs

@@ -233,6 +233,9 @@ fn main() {
                 "-Zmiri-ignore-leaks" => {
                     miri_config.ignore_leaks = true;
                 }
+                "-Zmiri-panic-on-unsupported-syscalls" => {
+                    miri_config.panic_on_unsupported = true;
+                }
                 "-Zmiri-track-raw-pointers" => {
                     miri_config.track_raw = true;
                 }

src/eval.rs

@@ -57,6 +57,8 @@ pub struct MiriConfig {
     /// If `Some`, enable the `measureme` profiler, writing results to a file
     /// with the specified prefix.
     pub measureme_out: Option<String>,
+    /// Panic when unsupported functionality is encountered
+    pub panic_on_unsupported: bool,
 }
 
 impl Default for MiriConfig {
@@ -77,6 +79,7 @@ impl Default for MiriConfig {
             data_race_detector: true,
             cmpxchg_weak_failure_rate: 0.8,
             measureme_out: None,
+            panic_on_unsupported: false,
         }
     }
 }

src/machine.rs

@@ -291,6 +291,11 @@ pub struct Evaluator<'mir, 'tcx> {
     /// Used with `profiler` to cache the `StringId`s for event names
     /// uesd with `measureme`.
     string_cache: FxHashMap<String, measureme::StringId>,
+
+    /// Whether to raise a panic in the context of the evaluated process when unsupported
+    /// functionality is encountered. If `false`, an error is propagated in the Miri application context 
+    /// instead (default behavior)
+    pub(crate) panic_on_unsupported: bool,
 }
 
 impl<'mir, 'tcx> Evaluator<'mir, 'tcx> {
@@ -318,6 +323,7 @@ impl<'mir, 'tcx> Evaluator<'mir, 'tcx> {
             static_roots: Vec::new(),
             profiler,
             string_cache: Default::default(),
+            panic_on_unsupported: config.panic_on_unsupported,
         }
     }
 }

src/shims/posix/linux/foreign_items.rs

@@ -182,7 +182,16 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
                     id if id == sys_futex => {
                         futex(this, args, dest)?;
                     }
-                    id => throw_unsup_format!("Miri does not support syscall ID {}", id),
+                    id => {
+                        let error_msg = format!("unsupported Miri functionality: syscall ID {} is not emulated", id);
+                        if this.eval_context_ref().machine.panic_on_unsupported {
+                            // message is slightly different here to make automated analysis easier
+                            this.start_panic(error_msg.as_ref(), StackPopUnwind::NotAllowed)?;
+                            return Ok(false);
+                        } else {
+                            throw_unsup_format!("{}", error_msg);
+                        }
+                    }
                 }
             }
 
@@ -214,7 +223,16 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
                 this.write_null(dest)?;
             }
 
-            _ => throw_unsup_format!("can't call foreign function: {}", link_name),
+            _ => {
+                let error_msg = format!("unsupported Miri functionality: can't call foreign function {:?}", link_name);
+                if this.eval_context_ref().machine.panic_on_unsupported {
+                    // message is slightly different here to make automated analysis easier
+                    this.start_panic(error_msg.as_ref(), StackPopUnwind::NotAllowed)?;
+                    return Ok(false);
+                } else {
+                    throw_unsup_format!("{}", error_msg);
+                }
+            }
         };
 
         Ok(true)

src/shims/posix/macos/foreign_items.rs

@@ -156,7 +156,16 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
                 this.write_scalar(addr, dest)?;
             }
 
-            _ => throw_unsup_format!("can't call foreign function: {}", link_name),
+            _ => {
+                let error_msg  = format!("unsupported Miri functionality: can't call foreign function {:?}", link_name);
+                if this.eval_context_ref().machine.panic_on_unsupported {
+                    // message is slightly different here to make automated analysis easier
+                    this.start_panic(error_msg.as_ref(), StackPopUnwind::NotAllowed)?;
+                    return Ok(false);
+                } else {
+                    throw_unsup_format!("{}", error_msg);
+                }
+            }
         };
 
         Ok(true)

src/shims/windows/foreign_items.rs

@@ -342,7 +342,14 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
             // Better error for attempts to create a thread
             "CreateThread" => {
                 check_abi(abi, Abi::System { unwind: false })?;
-                throw_unsup_format!("Miri does not support concurrency on Windows");
+
+                let error_msg = "unsupported Miri functionality: concurrency is not supported on Windows";
+                if this.eval_context_ref().machine.panic_on_unsupported {
+                    this.start_panic(error_msg, StackPopUnwind::NotAllowed)?;
+                    return Ok(false);
+                } else {
+                    throw_unsup_format!("{}", error_msg);
+                }
             }
 
             // Incomplete shims that we "stub out" just to get pre-main initialization code to work.
@@ -415,7 +422,16 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
                 this.write_scalar(Scalar::from_i32(1), dest)?;
             }
 
-            _ => throw_unsup_format!("can't call foreign function: {}", link_name),
+            _ => {
+                let error_msg = format!("unsupported Miri functionality: can't call foreign function {:?}", link_name);
+                if this.eval_context_ref().machine.panic_on_unsupported {
+                    // message is slightly different here to make automated analysis easier
+                    this.start_panic(error_msg.as_ref(), StackPopUnwind::NotAllowed)?;
+                    return Ok(false);
+                } else {
+                    throw_unsup_format!("{}", error_msg);
+                }
+            }
         }
 
         Ok(true)