Issue #19554 has been updated by ioquatix (Samuel Williams). Supporting Valgrind is a good idea. However, I actually prefer ASAN. But both are good tools. I recently added ASAN support for fibers/coroutines: https://github.com/ioquatix/ruby/commit/901525b1079ac02da0122a76d8e4c3546a7f... I also proposed to add it to the build matrix: https://github.com/ruby/ruby/pull/5939 You will probably find that without Valgrind knowing about the stack swapping, it won't work, you'll need to inform it when the stack is swapped. I don't really want to maintain two different implementations of "stack swapping instrumentation". I suppose we could abstract it out, however, it's fairly non-trivial/invasive. Therefore, it might be better to use ASAN over Valgrind to keep the code simpler. Or, if we decided Valgrind was better, we should remove ASAN, for example. ---------------------------------------- Bug #19554: Invalid memory access detected by Valgrind when using Fibers https://bugs.ruby-lang.org/issues/19554#change-102575 * Author: peterzhu2118 (Peter Zhu) * Status: Open * Priority: Normal * Backport: 2.7: UNKNOWN, 3.0: UNKNOWN, 3.1: UNKNOWN, 3.2: UNKNOWN ---------------------------------------- This issue was originally reported here: https://github.com/Shopify/ruby_memcheck/issues/14 Running the script shown below using `valgrind --trace-children=yes --num-callers=500 ruby test.rb` outputs a lot of invalid memory access errors. I've shown a few sample errors below. I am able to reproduce this issue on the master branch (commit [1e9a218ade](https://github.com/ruby/ruby/commit/1e9a218ade3af90c18f42e3fea08e2fcea81222a)), 3.2, 3.1, 3.0. ```ruby require "bundler/inline" gemfile do source "https://rubygems.org" gem "graphql" end module Example class FooType < GraphQL::Schema::Object field :id, ID, null: false end class FooSource < GraphQL::Dataloader::Source def fetch(ids) ids end end class QueryType < GraphQL::Schema::Object field :foo, Example::FooType do argument :foo_id, GraphQL::Types::ID, required: false, loads: Example::FooType end def foo(foo: nil); end end class Schema < GraphQL::Schema query Example::QueryType use GraphQL::Dataloader def self.object_from_id(id, ctx) ctx.dataloader.with(Example::FooSource).request(id) end end end Example::Schema.execute(<<-GRAPHQL) { foo(fooId: "Other") { id } } GRAPHQL ``` ``` ==203957== Use of uninitialised value of size 8 ==203957== at 0x3453FD: vm_exec_core (vm.inc:4411) ==203957== by 0x357EFB: rb_vm_exec (vm.c:2366) ==203957== by 0x354E44: invoke_block (vm.c:1384) ==203957== by 0x355759: invoke_iseq_block_from_c (vm.c:1440) ==203957== by 0x355759: invoke_block_from_c_proc (vm.c:1538) ==203957== by 0x355759: vm_invoke_proc (vm.c:1568) ==203957== by 0x355DF4: rb_vm_invoke_proc (vm.c:1589) ==203957== by 0x48F695: rb_fiber_start (cont.c:2513) ==203957== by 0x48CCF8: fiber_entry (cont.c:831) ==203957== ==203957== Invalid write of size 8 ==203957== at 0x48C407: fiber_pool_stack_reset (cont.c:325) ==203957== by 0x48C4E9: fiber_pool_vacancy_reset (cont.c:364) ==203957== by 0x48CBB0: fiber_pool_stack_release (cont.c:752) ==203957== by 0x48CECF: fiber_stack_release (cont.c:874) ==203957== by 0x48FC9F: fiber_switch (cont.c:2726) ==203957== by 0x4901F9: fiber_resume_kw (cont.c:2906) ==203957== by 0x490235: rb_fiber_resume_kw (cont.c:2912) ==203957== by 0x4903B7: rb_fiber_m_resume (cont.c:2973) ==203957== by 0x3337D6: ractor_safe_call_cfunc_m1 (vm_insnhelper.c:3166) ==203957== by 0x33440A: vm_call_cfunc_with_frame_ (vm_insnhelper.c:3357) ==203957== by 0x3345E1: vm_call_cfunc_with_frame (vm_insnhelper.c:3385) ==203957== by 0x3398E5: vm_sendish (vm_insnhelper.c:5225) ==203957== by 0x341203: vm_exec_core (insns.def:835) ==203957== by 0x357EFB: rb_vm_exec (vm.c:2366) ==203957== by 0x354E44: invoke_block (vm.c:1384) ==203957== by 0x355759: invoke_iseq_block_from_c (vm.c:1440) ==203957== by 0x355759: invoke_block_from_c_proc (vm.c:1538) ==203957== by 0x355759: vm_invoke_proc (vm.c:1568) ==203957== by 0x355DF4: rb_vm_invoke_proc (vm.c:1589) ==203957== by 0x48F695: rb_fiber_start (cont.c:2513) ==203957== by 0x48CCF8: fiber_entry (cont.c:831) ==203957== Address 0x9bad008 is in a rw- anonymous segment ``` -- https://bugs.ruby-lang.org/

Issue #19554 has been updated by ioquatix (Samuel Williams).

I haven't looked too much into ASAN, I'll look into it further. My main concern with ASAN is the need for Ruby to be compiled with it turned on and that additional code may need to be added into native extensions to support it. Both of these are barriers to entry compared to Valgrind.

It's unlikely that Valgrind will work with CRuby out of the box without Valgrind specific code e.g. for marking stacks, poisoning dead code, etc. I am okay to help you try it. Just don't underestimate how complicated it can be to get all the right feedback. e.g. ASAN poison is used for GC to mark regions of the memory that should not be accessed. The same is true for fibers. It already all works. ---------------------------------------- Bug #19554: Invalid memory access detected by Valgrind when using Fibers https://bugs.ruby-lang.org/issues/19554#change-102583 * Author: peterzhu2118 (Peter Zhu) * Status: Open * Priority: Normal * Backport: 2.7: UNKNOWN, 3.0: UNKNOWN, 3.1: UNKNOWN, 3.2: UNKNOWN ---------------------------------------- This issue was originally reported here: https://github.com/Shopify/ruby_memcheck/issues/14 Running the script shown below using `valgrind --trace-children=yes --num-callers=500 ruby test.rb` outputs a lot of invalid memory access errors. I've shown a few sample errors below. I am able to reproduce this issue on the master branch (commit [1e9a218ade](https://github.com/ruby/ruby/commit/1e9a218ade3af90c18f42e3fea08e2fcea81222a)), 3.2, 3.1, 3.0. ```ruby require "bundler/inline" gemfile do source "https://rubygems.org" gem "graphql" end module Example class FooType < GraphQL::Schema::Object field :id, ID, null: false end class FooSource < GraphQL::Dataloader::Source def fetch(ids) ids end end class QueryType < GraphQL::Schema::Object field :foo, Example::FooType do argument :foo_id, GraphQL::Types::ID, required: false, loads: Example::FooType end def foo(foo: nil); end end class Schema < GraphQL::Schema query Example::QueryType use GraphQL::Dataloader def self.object_from_id(id, ctx) ctx.dataloader.with(Example::FooSource).request(id) end end end Example::Schema.execute(<<-GRAPHQL) { foo(fooId: "Other") { id } } GRAPHQL ``` ``` ==203957== Use of uninitialised value of size 8 ==203957== at 0x3453FD: vm_exec_core (vm.inc:4411) ==203957== by 0x357EFB: rb_vm_exec (vm.c:2366) ==203957== by 0x354E44: invoke_block (vm.c:1384) ==203957== by 0x355759: invoke_iseq_block_from_c (vm.c:1440) ==203957== by 0x355759: invoke_block_from_c_proc (vm.c:1538) ==203957== by 0x355759: vm_invoke_proc (vm.c:1568) ==203957== by 0x355DF4: rb_vm_invoke_proc (vm.c:1589) ==203957== by 0x48F695: rb_fiber_start (cont.c:2513) ==203957== by 0x48CCF8: fiber_entry (cont.c:831) ==203957== ==203957== Invalid write of size 8 ==203957== at 0x48C407: fiber_pool_stack_reset (cont.c:325) ==203957== by 0x48C4E9: fiber_pool_vacancy_reset (cont.c:364) ==203957== by 0x48CBB0: fiber_pool_stack_release (cont.c:752) ==203957== by 0x48CECF: fiber_stack_release (cont.c:874) ==203957== by 0x48FC9F: fiber_switch (cont.c:2726) ==203957== by 0x4901F9: fiber_resume_kw (cont.c:2906) ==203957== by 0x490235: rb_fiber_resume_kw (cont.c:2912) ==203957== by 0x4903B7: rb_fiber_m_resume (cont.c:2973) ==203957== by 0x3337D6: ractor_safe_call_cfunc_m1 (vm_insnhelper.c:3166) ==203957== by 0x33440A: vm_call_cfunc_with_frame_ (vm_insnhelper.c:3357) ==203957== by 0x3345E1: vm_call_cfunc_with_frame (vm_insnhelper.c:3385) ==203957== by 0x3398E5: vm_sendish (vm_insnhelper.c:5225) ==203957== by 0x341203: vm_exec_core (insns.def:835) ==203957== by 0x357EFB: rb_vm_exec (vm.c:2366) ==203957== by 0x354E44: invoke_block (vm.c:1384) ==203957== by 0x355759: invoke_iseq_block_from_c (vm.c:1440) ==203957== by 0x355759: invoke_block_from_c_proc (vm.c:1538) ==203957== by 0x355759: vm_invoke_proc (vm.c:1568) ==203957== by 0x355DF4: rb_vm_invoke_proc (vm.c:1589) ==203957== by 0x48F695: rb_fiber_start (cont.c:2513) ==203957== by 0x48CCF8: fiber_entry (cont.c:831) ==203957== Address 0x9bad008 is in a rw- anonymous segment ``` -- https://bugs.ruby-lang.org/

Issue #19554 has been updated by mdalessio (Mike Dalessio). I'm just here to support Peter's take: Valgrind is a very useful tool for C extension maintainers to find and prevent illegal memory access. It's been an incredibly valuable tool for me over the ~15 years I've been a maintainer, and is a key tool in Nokogiri's CI pipelines. ASan is also useful! But because it's a build-time option, it's slightly less useful for debugging production builds. If it's not too difficult, I think Ruby should support both tools. ---------------------------------------- Bug #19554: Invalid memory access detected by Valgrind when using Fibers https://bugs.ruby-lang.org/issues/19554#change-102594 * Author: peterzhu2118 (Peter Zhu) * Status: Open * Priority: Normal * Backport: 2.7: UNKNOWN, 3.0: UNKNOWN, 3.1: UNKNOWN, 3.2: UNKNOWN ---------------------------------------- This issue was originally reported here: https://github.com/Shopify/ruby_memcheck/issues/14 Running the script shown below using `valgrind --trace-children=yes --num-callers=500 ruby test.rb` outputs a lot of invalid memory access errors. I've shown a few sample errors below. I am able to reproduce this issue on the master branch (commit [1e9a218ade](https://github.com/ruby/ruby/commit/1e9a218ade3af90c18f42e3fea08e2fcea81222a)), 3.2, 3.1, 3.0. ```ruby require "bundler/inline" gemfile do source "https://rubygems.org" gem "graphql" end module Example class FooType < GraphQL::Schema::Object field :id, ID, null: false end class FooSource < GraphQL::Dataloader::Source def fetch(ids) ids end end class QueryType < GraphQL::Schema::Object field :foo, Example::FooType do argument :foo_id, GraphQL::Types::ID, required: false, loads: Example::FooType end def foo(foo: nil); end end class Schema < GraphQL::Schema query Example::QueryType use GraphQL::Dataloader def self.object_from_id(id, ctx) ctx.dataloader.with(Example::FooSource).request(id) end end end Example::Schema.execute(<<-GRAPHQL) { foo(fooId: "Other") { id } } GRAPHQL ``` ``` ==203957== Use of uninitialised value of size 8 ==203957== at 0x3453FD: vm_exec_core (vm.inc:4411) ==203957== by 0x357EFB: rb_vm_exec (vm.c:2366) ==203957== by 0x354E44: invoke_block (vm.c:1384) ==203957== by 0x355759: invoke_iseq_block_from_c (vm.c:1440) ==203957== by 0x355759: invoke_block_from_c_proc (vm.c:1538) ==203957== by 0x355759: vm_invoke_proc (vm.c:1568) ==203957== by 0x355DF4: rb_vm_invoke_proc (vm.c:1589) ==203957== by 0x48F695: rb_fiber_start (cont.c:2513) ==203957== by 0x48CCF8: fiber_entry (cont.c:831) ==203957== ==203957== Invalid write of size 8 ==203957== at 0x48C407: fiber_pool_stack_reset (cont.c:325) ==203957== by 0x48C4E9: fiber_pool_vacancy_reset (cont.c:364) ==203957== by 0x48CBB0: fiber_pool_stack_release (cont.c:752) ==203957== by 0x48CECF: fiber_stack_release (cont.c:874) ==203957== by 0x48FC9F: fiber_switch (cont.c:2726) ==203957== by 0x4901F9: fiber_resume_kw (cont.c:2906) ==203957== by 0x490235: rb_fiber_resume_kw (cont.c:2912) ==203957== by 0x4903B7: rb_fiber_m_resume (cont.c:2973) ==203957== by 0x3337D6: ractor_safe_call_cfunc_m1 (vm_insnhelper.c:3166) ==203957== by 0x33440A: vm_call_cfunc_with_frame_ (vm_insnhelper.c:3357) ==203957== by 0x3345E1: vm_call_cfunc_with_frame (vm_insnhelper.c:3385) ==203957== by 0x3398E5: vm_sendish (vm_insnhelper.c:5225) ==203957== by 0x341203: vm_exec_core (insns.def:835) ==203957== by 0x357EFB: rb_vm_exec (vm.c:2366) ==203957== by 0x354E44: invoke_block (vm.c:1384) ==203957== by 0x355759: invoke_iseq_block_from_c (vm.c:1440) ==203957== by 0x355759: invoke_block_from_c_proc (vm.c:1538) ==203957== by 0x355759: vm_invoke_proc (vm.c:1568) ==203957== by 0x355DF4: rb_vm_invoke_proc (vm.c:1589) ==203957== by 0x48F695: rb_fiber_start (cont.c:2513) ==203957== by 0x48CCF8: fiber_entry (cont.c:831) ==203957== Address 0x9bad008 is in a rw- anonymous segment ``` -- https://bugs.ruby-lang.org/