Save exit Wasm FP and PC in component-to-host trampolines (#4601)

* Wasmtime: Add a pointer to `VMRuntimeLimits` in component contexts

* Save exit Wasm FP and PC in component-to-host trampolines

Fixes #4535

* Add comment about why we deref the trampoline's FP

* Update some tests to use new `vmruntime_limits_*` methods
This commit is contained in:
Nick Fitzgerald
2022-08-04 08:27:30 -07:00
committed by GitHub
parent f69acd6187
commit 70ce288dc7
16 changed files with 206 additions and 149 deletions

View File

@@ -222,61 +222,57 @@ fn attempt_to_leave_during_malloc() -> Result<()> {
let component = Component::new(&engine, component)?;
let mut store = Store::new(&engine, ());
// TODO(#4535): we need to fold the Wasm<--->host trampoline functionality into
// component trampolines. Until then, we panic when getting a backtrace here.
if false {
// Assert that during a host import if we return values to wasm that a trap
// happens if we try to leave the instance.
let trap = linker
.instantiate(&mut store, &component)?
.get_typed_func::<(), (), _>(&mut store, "run")?
.call(&mut store, ())
.unwrap_err()
.downcast::<Trap>()?;
assert!(
trap.to_string().contains("cannot leave component instance"),
"bad trap: {}",
trap,
);
// Assert that during a host import if we return values to wasm that a trap
// happens if we try to leave the instance.
let trap = linker
.instantiate(&mut store, &component)?
.get_typed_func::<(), (), _>(&mut store, "run")?
.call(&mut store, ())
.unwrap_err()
.downcast::<Trap>()?;
assert!(
trap.to_string().contains("cannot leave component instance"),
"bad trap: {}",
trap,
);
let trace = trap.trace().unwrap();
assert_eq!(trace.len(), 4);
let trace = trap.trace().unwrap();
assert_eq!(trace.len(), 4);
// This was our entry point...
assert_eq!(trace[3].module_name(), Some("m"));
assert_eq!(trace[3].func_name(), Some("run"));
// This was our entry point...
assert_eq!(trace[3].module_name(), Some("m"));
assert_eq!(trace[3].func_name(), Some("run"));
// ... which called an imported function which ends up being originally
// defined by the shim instance. The shim instance then does an indirect
// call through a table which goes to the `canon.lower`'d host function
assert_eq!(trace[2].module_name(), Some("host_shim"));
assert_eq!(trace[2].func_name(), Some("shim_ret_string"));
// ... which called an imported function which ends up being originally
// defined by the shim instance. The shim instance then does an indirect
// call through a table which goes to the `canon.lower`'d host function
assert_eq!(trace[2].module_name(), Some("host_shim"));
assert_eq!(trace[2].func_name(), Some("shim_ret_string"));
// ... and the lowered host function will call realloc to allocate space for
// the result
assert_eq!(trace[1].module_name(), Some("m"));
assert_eq!(trace[1].func_name(), Some("realloc"));
// ... and the lowered host function will call realloc to allocate space for
// the result
assert_eq!(trace[1].module_name(), Some("m"));
assert_eq!(trace[1].func_name(), Some("realloc"));
// ... but realloc calls the shim instance and tries to exit the
// component, triggering a dynamic trap
assert_eq!(trace[0].module_name(), Some("host_shim"));
assert_eq!(trace[0].func_name(), Some("shim_thunk"));
// ... but realloc calls the shim instance and tries to exit the
// component, triggering a dynamic trap
assert_eq!(trace[0].module_name(), Some("host_shim"));
assert_eq!(trace[0].func_name(), Some("shim_thunk"));
// In addition to the above trap also ensure that when we enter a wasm
// component if we try to leave while lowering then that's also a dynamic
// trap.
let trap = linker
.instantiate(&mut store, &component)?
.get_typed_func::<(&str,), (), _>(&mut store, "take-string")?
.call(&mut store, ("x",))
.unwrap_err()
.downcast::<Trap>()?;
assert!(
trap.to_string().contains("cannot leave component instance"),
"bad trap: {}",
trap,
);
}
// In addition to the above trap also ensure that when we enter a wasm
// component if we try to leave while lowering then that's also a dynamic
// trap.
let trap = linker
.instantiate(&mut store, &component)?
.get_typed_func::<(&str,), (), _>(&mut store, "take-string")?
.call(&mut store, ("x",))
.unwrap_err()
.downcast::<Trap>()?;
assert!(
trap.to_string().contains("cannot leave component instance"),
"bad trap: {}",
trap,
);
Ok(())
}
@@ -605,24 +601,21 @@ fn bad_import_alignment() -> Result<()> {
let component = Component::new(&engine, component)?;
let mut store = Store::new(&engine, ());
// TODO(#4535): we need to fold the Wasm<--->host trampoline functionality into
// component trampolines. Until then, we panic when getting a backtrace here.
if false {
let trap = linker
.instantiate(&mut store, &component)?
.get_typed_func::<(), (), _>(&mut store, "unaligned-retptr")?
.call(&mut store, ())
.unwrap_err()
.downcast::<Trap>()?;
assert!(trap.to_string().contains("pointer not aligned"), "{}", trap);
let trap = linker
.instantiate(&mut store, &component)?
.get_typed_func::<(), (), _>(&mut store, "unaligned-argptr")?
.call(&mut store, ())
.unwrap_err()
.downcast::<Trap>()?;
assert!(trap.to_string().contains("pointer not aligned"), "{}", trap);
}
let trap = linker
.instantiate(&mut store, &component)?
.get_typed_func::<(), (), _>(&mut store, "unaligned-retptr")?
.call(&mut store, ())
.unwrap_err()
.downcast::<Trap>()?;
assert!(trap.to_string().contains("pointer not aligned"), "{}", trap);
let trap = linker
.instantiate(&mut store, &component)?
.get_typed_func::<(), (), _>(&mut store, "unaligned-argptr")?
.call(&mut store, ())
.unwrap_err()
.downcast::<Trap>()?;
assert!(trap.to_string().contains("pointer not aligned"), "{}", trap);
Ok(())
}