From: jacknagel@...
Date: 2014-10-13T17:16:54+00:00
Subject: [ruby-core:65678] [ruby-trunk - Bug #10290] segfault when calling a lambda recursively after rescuing SystemStackError

Issue #10290 has been updated by Jack Nagel.


I can reproduce it on 2.0.0-p576 when compiled with `-Os`, but not `-O2`:

```
$ make clean && ./configure --disable-install-doc CC=clang CFLAGS=-O2 && make -j12
$ ./miniruby -v
ruby 2.0.0p576 (2014-09-19 revision 47627) [x86_64-darwin13.4.0]
$ ./miniruby -e "l = -> { l.() }; begin; l.(); rescue SystemStackError; l.(); end"
-e:1: stack level too deep (SystemStackError)

$ make clean && ./configure --disable-install-doc CC=clang CFLAGS=-Os && make -j12
$ ./miniruby -v
ruby 2.0.0p576 (2014-09-19 revision 47627) [x86_64-darwin13.4.0]
$ ./miniruby -e "l = -> { l.() }; begin; l.(); rescue SystemStackError; l.(); end"
Segmentation fault: 11
```

On 2.1.3, it does not happen when compiled without optimizations, but even using `-O1` is enough to trigger it:

```
$ make clean && ./configure --disable-install-doc CC=clang && make -j12
$ ./miniruby -v
ruby 2.1.3p242 (2014-09-19 revision 47629) [x86_64-darwin13.0]
$ ./miniruby -e "l = -> { l.() }; begin; l.(); rescue SystemStackError; l.(); end"
-e:1: stack level too deep (SystemStackError)

$ make clean && ./configure --disable-install-doc CC=clang CFLAGS=-O1 && make -j12
$ ./miniruby -v
ruby 2.1.3p242 (2014-09-19 revision 47629) [x86_64-darwin13.0]
$ ./miniruby -e "l = -> { l.() }; begin; l.(); rescue SystemStackError; l.(); end"
Segmentation fault: 11
```

And similarly on trunk, it is triggered with `-O1` or higher:

```
$ make clean && ./configure --disable-install-doc CC=clang && make -j12
$ ./miniruby -v
ruby 2.2.0dev (2014-10-14 trunk 47906) [x86_64-darwin13]
$ ./miniruby -e "l = -> { l.() }; begin; l.(); rescue SystemStackError; l.(); end"
-e:1:in `call': stack level too deep (SystemStackError)

make clean && ./configure --disable-install-doc CC=clang CFLAGS=-O1 && make -j12
$ ./miniruby -v
ruby 2.2.0dev (2014-10-14 trunk 47906) [x86_64-darwin13]
$ ./miniruby -e "l = -> { l.() }; begin; l.(); rescue SystemStackError; l.(); end"
Segmentation fault: 11
```

I'm using the latest Apple clang:

```
$ clang --version
Apple LLVM version 6.0 (clang-600.0.54) (based on LLVM 3.5svn)
Target: x86_64-apple-darwin13.4.0
Thread model: posix
```

----------------------------------------
Bug #10290: segfault when calling a lambda recursively after rescuing SystemStackError
https://bugs.ruby-lang.org/issues/10290#change-49410

* Author: Jack Nagel
* Status: Feedback
* Priority: Normal
* Assignee: 
* Category: 
* Target version: 
* ruby -v: ruby 2.1.3p242 (2014-09-19 revision 47629) [x86_64-darwin13.0]
* Backport: 2.0.0: UNKNOWN, 2.1: UNKNOWN
----------------------------------------
The following code segfaults on Ruby 2.1.3:

```
l = -> { l.() }

begin
  l.()
rescue SystemStackError
  l.() # segfault
end
```

the issue does not occur on trunk.

---Files--------------------------------
ruby_2014-09-25-000925_haswell.log (46.4 KB)
ruby_2014-09-25-001644_haswell.log (46.8 KB)


-- 
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