Bug #15162: Encoding::Converter.search_convpath(Encoding::ASCII_8BIT, Encoding::Emacs_Mule) crashes on MinGW

• Status: Closed
• Assignee: -
• Target version: -
• ruby -v: ruby 2.6.0dev (2018-09-26) [x64-mingw32]
• Backport: 2.3: REQUIRED, 2.4: DONE, 2.5: DONE

[Eregon (Benoit Daloze)]

It seems to work fine with String arguments, but not Encoding objects where it SEGV, at least in some runs.
See https://github.com/ruby/ruby/commit/f00bf242724d40d59a242c6bf9e567d18c9e1872#commitcomment-30650955

cc @MSP-Greg (Greg L)

[h.shirosaki (Hiroshi Shirosaki)]

• File 0001-transcode.c-add-GC-guard-on-raise.patch 0001-transcode.c-add-GC-guard-on-raise.patch added

I found a smaller test to reproduce SEGV.

$ ./miniruby -ve "loop do loop do loop do Encoding::Converter.search_convpath(Encoding::ASCII_8BIT, Encoding::ASCII_8BIT) end end end"
ruby 2.6.0dev (2018-09-26 trunk 64852) [x64-mingw32]
Segmentation fault

Maybe GC guard is not sufficient? Attached patch fixes SEGV on my test.

[MSP-Greg (Greg L)]

@hsbt (Hiroshi SHIBATA), thanks for the work on this. I (quickly) did a lambda in a block, and that didn't cause the SEGV.

Using existing ruby-loco builds (I save all of them locally), I found that the issue doesn't exist on:
ruby 2.6.0dev (2018-09-26 trunk 64845) [x64-mingw32]

but does exist on:
ruby 2.6.0dev (2018-09-26 trunk 64851) [x64-mingw32]

I'll check the patch later, Greg

[MSP-Greg (Greg L)]

@hsbt (Hiroshi SHIBATA)

I just did twenty runs of core/encoding, then twenty runs of the full spec suite. No silent SEGV's.

Hence, the patch works. Thank you. Whoever does the commmit, please remember to remove the two .name method calls on line 30 of spec/ruby/core/encoding/converter/search_convpath_spec.rb

Benoit - I can't seem to ping you using either @Eregon (Benoit Daloze) or @Eregon (Benoit Daloze)

[hsbt (Hiroshi SHIBATA)]

@MSP-Greg (Greg L)

You mistake to mention about @shirosaki, not @hsbt.

[MSP-Greg (Greg L)]

@hsbt (Hiroshi SHIBATA) & @h.shirosaki (Hiroshi Shirosaki)

I apologize for that mistake. I hope to not make it again.

We have a saying something like 'foot in mouth' referring to speech. I'm not sure what the equivalent is for written... Thanks, Greg

[Eregon (Benoit Daloze)]

MSP-Greg (Greg L) wrote:

Benoit - I can't seem to ping you using either @Eregon (Benoit Daloze) or @Eregon (Benoit Daloze)

Odd, not sure why it doesn't work.

[h.shirosaki (Hiroshi Shirosaki)]

• Related to Bug #12411: Warnings when compiling transcode.c on cygwin added

[h.shirosaki (Hiroshi Shirosaki)]

Thank you for test.
This issue seems to be related to #12411 fix.

• Status changed from Open to Closed

Applied in changeset trunk|r64879.

---

transcode.c: add GC guard on raise

• transcode.c (econv_s_search_convpath): add GC guard to fix SEGV
  on raise.
  [Bug #15162] [ruby-core:89172]

[nagachika (Tomoyuki Chikanaga)]

• Backport changed from 2.3: UNKNOWN, 2.4: UNKNOWN, 2.5: UNKNOWN to 2.3: REQUIRED, 2.4: REQUIRED, 2.5: REQUIRED

[nagachika (Tomoyuki Chikanaga)]

• Backport changed from 2.3: REQUIRED, 2.4: REQUIRED, 2.5: REQUIRED to 2.3: REQUIRED, 2.4: REQUIRED, 2.5: DONE

ruby_2_5 r66881 merged revision(s) 64879.

[usa (Usaku NAKAMURA)]

• Backport changed from 2.3: REQUIRED, 2.4: REQUIRED, 2.5: DONE to 2.3: REQUIRED, 2.4: DONE, 2.5: DONE

ruby_2_4 r66961 merged revision(s) 64879.