From 5bcba2a5ee5d331f6979fcaff11ac00ee15d7508 Mon Sep 17 00:00:00 2001 From: Alan Wu Date: Tue, 22 Sep 2020 17:02:15 -0400 Subject: [PATCH] Add workaround for inserting into addr2insn mapping --- ujit_compile.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/ujit_compile.c b/ujit_compile.c index bfe75d1b7b..5980df59f5 100644 --- a/ujit_compile.c +++ b/ujit_compile.c @@ -64,7 +64,14 @@ addr2insn_bookkeeping(void *code_ptr, int insn) const void * const translated_address = table[insn]; st_data_t encoded_insn_data; if (st_lookup(rb_encoded_insn_data, (st_data_t)translated_address, &encoded_insn_data)) { - st_insert(rb_encoded_insn_data, (st_data_t)code_ptr, encoded_insn_data); + // This is a roundabout way of doing an insert. Doing a plain insert can cause GC + // while inserting. While inserting, the table is in an inconsistent state and the + // GC can do a lookup in the table. + st_table *new_table = st_copy(rb_encoded_insn_data); + st_table *old_table = rb_encoded_insn_data; + st_insert(new_table, (st_data_t)code_ptr, encoded_insn_data); + rb_encoded_insn_data = new_table; + st_free_table(old_table); } else { rb_bug("ujit: failed to find info for original instruction while dealing with addr2insn");