summaryrefslogtreecommitdiff
path: root/vm_core.h
diff options
context:
space:
mode:
authorStan Lo <stan.lo@shopify.com>2023-01-16 20:42:51 +0000
committerPeter Zhu <peter@peterzhu.ca>2023-01-17 08:01:19 -0500
commitdf6b72b8ff7af16a56fa48f3b4abb1d8850f4d1c (patch)
tree67fd7da4f7a26e5e1af3153eba8581c5dc49c400 /vm_core.h
parent9399352a43253e2905d76d21774fb0301069197b (diff)
downloadruby-df6b72b8ff7af16a56fa48f3b4abb1d8850f4d1c.tar.gz
Avoid checking interrupt when loading iseq
The interrupt check will unintentionally release the VM lock when loading an iseq. And this will cause issues with the `debug` gem's [`ObjectSpace.each_iseq` method](https://github.com/ruby/debug/blob/0fcfc28acae33ec1c08068fb7c33703cfa681fa7/ext/debug/iseq_collector.c#L61-L67), which wraps iseqs with a wrapper and exposes their internal states when they're actually not ready to be used. And when that happens, errors like this would occur and kill the `debug` gem's thread: ``` DEBUGGER: ReaderThreadError: uninitialized InstructionSequence ┃ DEBUGGER: Disconnected. ┃ ["/opt/rubies/ruby-3.2.0/lib/ruby/gems/3.2.0/gems/debug-1.7.1/lib/debug/breakpoint.rb:247:in `absolute_path'", ┃ "/opt/rubies/ruby-3.2.0/lib/ruby/gems/3.2.0/gems/debug-1.7.1/lib/debug/breakpoint.rb:247:in `block in iterate_iseq'", ┃ "/opt/rubies/ruby-3.2.0/lib/ruby/gems/3.2.0/gems/debug-1.7.1/lib/debug/breakpoint.rb:246:in `each_iseq'", ... ``` A way to reproduce the issue is to satisfy these conditions at the same time: 1. `debug` gem calling `ObjectSpace.each_iseq` (e.g. [activating a `LineBreakpoint`](https://github.com/ruby/debug/blob/0fcfc28acae33ec1c08068fb7c33703cfa681fa7/lib/debug/breakpoint.rb#L246)). 2. A large amount of iseq being loaded from another thread (possibly through the `bootsnap` gem). 3. 1 and 2 iterating through the same iseq(s) at the same time. Because this issue requires external dependencies and a rather complicated timing setup to reproduce, I wasn't able to write a test case for it. But here's some pseudo code to help reproduce it: ```rb require "debug/session" Thread.new do 100.times do ObjectSpace.each_iseq do |iseq| iseq.absolute_path end end end sleep 0.1 load_a_bunch_of_iseq possibly_through_bootsnap ``` [Bug #19348] Co-authored-by: Peter Zhu <peter@peterzhu.ca>
Diffstat (limited to 'vm_core.h')
-rw-r--r--vm_core.h1
1 files changed, 1 insertions, 0 deletions
diff --git a/vm_core.h b/vm_core.h
index 1f5c56aa17..c67b3a5f4b 100644
--- a/vm_core.h
+++ b/vm_core.h
@@ -1747,6 +1747,7 @@ const VALUE *rb_binding_add_dynavars(VALUE bindval, rb_binding_t *bind, int dync
void rb_vm_inc_const_missing_count(void);
VALUE rb_vm_call_kw(rb_execution_context_t *ec, VALUE recv, VALUE id, int argc,
const VALUE *argv, const rb_callable_method_entry_t *me, int kw_splat);
+void rb_vm_pop_frame_no_int(rb_execution_context_t *ec);
MJIT_STATIC void rb_vm_pop_frame(rb_execution_context_t *ec);
void rb_thread_start_timer_thread(void);