Free jump buffers leaked by `cont_restore_thread` in WASI builds

1 files changed, 45 insertions, 0 deletions

diff --git a/cont.c b/cont.c
index 072ae4562f..960d51f214 100644
--- a/cont.c
+++ b/cont.c
@@ -1511,6 +1511,51 @@ cont_restore_thread(rb_context_t *cont)
 rb_raise(rb_eRuntimeError, "can't call across trace_func");
 }

+#if defined(__wasm__) && !defined(__EMSCRIPTEN__)
+ if (th->ec->tag != sec->tag) {
+ /* find the lowest common ancestor tag of the current EC and the saved EC */
+
+ struct rb_vm_tag *lowest_common_ancestor = NULL;
+ size_t num_tags = 0;
+ size_t num_saved_tags = 0;
+ for (struct rb_vm_tag *tag = th->ec->tag; tag != NULL; tag = tag->prev) {
+ ++num_tags;
+ }
+ for (struct rb_vm_tag *tag = sec->tag; tag != NULL; tag = tag->prev) {
+ ++num_saved_tags;
+ }
+
+ size_t min_tags = num_tags <= num_saved_tags ? num_tags : num_saved_tags;
+
+ struct rb_vm_tag *tag = th->ec->tag;
+ while (num_tags > min_tags) {
+ tag = tag->prev;
+ --num_tags;
+ }
+
+ struct rb_vm_tag *saved_tag = sec->tag;
+ while (num_saved_tags > min_tags) {
+ saved_tag = saved_tag->prev;
+ --num_saved_tags;
+ }
+
+ while (min_tags > 0) {
+ if (tag == saved_tag) {
+ lowest_common_ancestor = tag;
+ break;
+ }
+ tag = tag->prev;
+ saved_tag = saved_tag->prev;
+ --min_tags;
+ }
+
+ /* free all the jump buffers between the current EC's tag and the lowest common ancestor tag */
+ for (struct rb_vm_tag *tag = th->ec->tag; tag != lowest_common_ancestor; tag = tag->prev) {
+ rb_vm_tag_jmpbuf_deinit(&tag->buf);
+ }
+ }
+#endif
+
 /* copy vm stack */
 #ifdef CAPTURE_JUST_VALID_VM_STACK
 MEMCPY(th->ec->vm_stack,