Bug #19716
closedSystemStackError occurs too easily on Alpine Linux (due to small stack size reported by pthread_attr_getstacksize on musl libc)
Description
This is the same problem previously reported against Ruby 2.5 in https://bugs.ruby-lang.org/issues/14387. I just ran into the same problem on Ruby 3.1.4, built on Alpine Linux 3.16.
@hsbt (Hiroshi SHIBATA) stated in the previous thread (https://bugs.ruby-lang.org/issues/14387#note-28):
If you have this issue with Ruby 3.2, please file it with another issue.
I hacked stack_check
in gc.c to print the values of STACK_START
and STACK_END
on stack overflow; on the Alpine 3.16 host where this problem just occurred, the values printed were:
Start=0x7ffd0bf4f000, End=0x7ffd0bf32530
...which shows that Ruby thinks the stack size is only 131072 bytes. On the other hand, ulimit -s
shows a stack size limit of 8192kb.
This Ruby 3.1.4 was built from unmodified source code downloaded from https://cache.ruby-lang.org; the build was configured using CFLAGS='-march=native' ./configure --disable-install-doc
.
The invocation of Ruby which blew the stack was bundle exec rake db:migrate
, on a mid-sized Rails project.
Regarding @ncopa's patch from #14387, @wanabe (_ wanabe) listed some things which should be done before it is merged into mainline Ruby:
Okay, The patch needs one or more proofs of its behaviour, like that:
Original issue [ruby-dev:50421] has gone away.
Standard test codes run well.
test-all
ruby/spec
getrlimit works on some situations like:
on single thread
with multiple threads
with RLIMIT_STACK environment variable
getrlimit code of musl is implemented correctly as expected.
(But It's doubtful whether it can be. I guess that a proof of code soundness is very difficult.)
Some "real world" applications can work.
I think it is better example that that application(s) can't work without the patch.
I am happy to help cover some of these points if the Ruby development team is still interested in merging @ncopa's patch.
Updated by alexdowad (Alex Dowad) over 1 year ago
I just applied @ncopa's patch from: https://bugs.ruby-lang.org/attachments/download/7081/0001-thread_pthread.c-make-get_main_stack-portable-on-lin.patch
After make
and make install
, I am now able to run bundle exec rake db:migrate
normally.
Commands used were:
wget -O 'thread-stack-fix.patch' 'https://bugs.ruby-lang.org/attachments/download/7081/0001-thread_pthread.c-make-get_main_stack-portable-on-lin.patch'
patch -p1 -i thread-stack-fix.patch
rm thread-stack-fix.patch
make
make install
Updated by alexdowad (Alex Dowad) over 1 year ago
Output from make test
after applying the patch:
Fiber count: 10000 (skipping)
PASS all 1669 tests
exec ./miniruby -I./lib -I. -I.ext/common ./tool/runruby.rb --extout=.ext -- --disable-gems "./bootstraptest/runner.rb" --ruby="ruby --disable-gems" ./KNOWNBUGS.rb
2023-06-07 00:26:25 +0000
Driver is ruby 3.1.4p223 (2023-03-30 revision 957bb7cb81) [x86_64-linux-musl]
Target is ruby 3.1.4p223 (2023-03-30 revision 957bb7cb81) [x86_64-linux-musl]
KNOWNBUGS.rb PASS 0
No tests, no problem
test succeeded
Updated by retro (Josef Šimánek) about 1 year ago
It would be great to get this fixed finally. There are no bugs reported, since Alpine linux is used mostly as Docker container system and official Ruby alpine image already includes the patch https://github.com/docker-library/ruby/blob/31c1fdba369192fe2c3cf327d7d98819edc1400b/3.2/alpine3.18/Dockerfile#L102-L106. RubyGems.org runs on this Alpine image for last few years already with this patch.
I tried this patch on Ruby 3.2.2 on GLIBC Linux (Fedora).
$ make test-all
...
Finished tests in 957.018822s, 24.4938 tests/s, 5851.8306 assertions/s.
23441 tests, 5600312 assertions, 0 failures, 0 errors, 89 skips
ruby -v: ruby 3.2.2 (2023-03-30 revision e51014f9c0) [x86_64-linux]
Updated by hsbt (Hiroshi SHIBATA) 8 months ago
- Status changed from Open to Closed
Unfortunately, there is no active maintainer for musl or alpine platform.
I tagged them to musl. We welcome patch for them.
Updated by mame (Yusuke Endoh) 8 months ago
- Status changed from Closed to Feedback
Updated by ncopa (Natanael Copa) 8 months ago
hsbt (Hiroshi SHIBATA) wrote in #note-5:
We welcome patch for them.
Patch has been available for for years. https://bugs.ruby-lang.org/issues/19716#note-2 confirms it still works for musl, and https://bugs.ruby-lang.org/issues/19716#note-3 confirms it does not break glibc.
How do you want me to submit the patch?