https://git.ruby-lang.org/ruby.git/commit/?id=0d17cdd0ac

From 0d17cdd0ac3ae0f3f3608e5430b68467a6a13cc7 Mon Sep 17 00:00:00 2001
From: Alan Wu <XrXr@u...>
Date: Thu, 15 Oct 2020 14:51:30 -0400
Subject: Abort on system stack overflow during GC

Buggy native extensions could have mark functions that cause stack
overflow. When a stack overflow happens during GC, Ruby used to recover
by raising an exception, which runs the interpreter. It's not safe to
run the interpreter during GC since the GC is in an inconsistent state.
This could cause object allocation during GC, for example.

Instead of running the interpreter and potentially causing a crash down
the line, fail fast and abort.

diff --git a/vm_insnhelper.c b/vm_insnhelper.c
index 275e5f7..9eedc10 100644
--- a/vm_insnhelper.c
+++ b/vm_insnhelper.c
@@ -83,7 +83,10 @@ NORETURN(MJIT_STATIC void rb_ec_stack_overflow(rb_execution_context_t *ec, int c https://github.com/ruby/ruby/blob/trunk/vm_insnhelper.c#L83
 MJIT_STATIC void
 rb_ec_stack_overflow(rb_execution_context_t *ec, int crit)
 {
-    if (crit || rb_during_gc()) {
+    if (rb_during_gc()) {
+        rb_bug("system stack overflow during GC. Faulty native extension?");
+    }
+    if (crit) {
 	ec->raised_flag = RAISED_STACKOVERFLOW;
 	ec->errinfo = rb_ec_vm_ptr(ec)->special_exceptions[ruby_error_stackfatal];
 	EC_JUMP_TAG(ec, TAG_RAISE);
-- 
cgit v0.10.2


--
ML: ruby-changes@q...
Info: http://www.atdot.net/~ko1/quickml/