T0b1/wasmtime
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Make module information lookup from runtime safe.

Browse Source 
This commit uses a two-phase lookup of stack map information from modules
rather than giving back raw pointers to stack maps.

First the runtime looks up information about a module from a pc value, which
returns an `Arc` it keeps a reference on while completing the stack map lookup.

Second it then queries the module information for the stack map from a pc
value, getting a reference to the stack map (which is now safe because of the
`Arc` held by the runtime).
This commit is contained in:
Peter Huene
2021-04-16 12:05:38 -07:00
parent 6ac1321162
commit b775b68cfb
15 changed files with 116 additions and 112 deletions
Download Patch File Download Diff File Expand all files Collapse all files

8
crates/runtime/src/instance.rs
View File

@@ -3,7 +3,7 @@
//! `InstanceHandle` is a reference-counting handle for an `Instance`.
use crate::export::Export;
use crate::externref::{StackMapLookup, VMExternRefActivationsTable};
use crate::externref::{ModuleInfoLookup, VMExternRefActivationsTable};
use crate::memory::{Memory, RuntimeMemoryCreator};
use crate::table::{Table, TableElement};
use crate::traphandlers::Trap;
@@ -249,9 +249,9 @@ impl Instance {
unsafe { self.vmctx_plus_offset(self.offsets.vmctx_externref_activations_table()) }
}
/// Return a pointer to the `StackMapLookup`.
pub fn stack_map_lookup(&self) -> *mut *const dyn StackMapLookup {
unsafe { self.vmctx_plus_offset(self.offsets.vmctx_stack_map_lookup()) }
/// Return a pointer to the `ModuleInfoLookup`.
pub fn module_info_lookup(&self) -> *mut *const dyn ModuleInfoLookup {
unsafe { self.vmctx_plus_offset(self.offsets.vmctx_module_info_lookup()) }
}
/// Return a reference to the vmctx used by compiled wasm code.