Issue #8680 has been updated by halfie (Ruby Guy).

File 0001-Enable-usage-of-AddressSanitizer-in-CRuby.patch added

Attaching latest patch against tip. Feedback is welcome.
----------------------------------------
Bug #8680: ruby crashes when built with AddressSanitizer
https://bugs.ruby-lang.org/issues/8680#change-41975

Author: halfie (Ruby Guy)
Status: Feedback
Priority: Normal
Assignee: 
Category: core
Target version: 
ruby -v: 6398f79853f73fd307f5ecd266a94644ecf625b9
Backport: 1.9.3: UNKNOWN, 2.0.0: UNKNOWN


ruby crashes when built with AddressSanitizer (http://clang.llvm.org/docs/AddressSanitizer.html).

To reproduce the problem, try to build latest ruby from trunk.

$ gcc --version
gcc (GCC) 4.8.1 20130603 (Red Hat 4.8.1-1)
...

$ export CFLAGS="-fsanitize=address -O2 -g"
$ export LDFLAGS="-fsanitize=address"
$ ./configure
$ make
...
processing probes in object files
rm -f probes.o
linking miniruby
=================================================================
==13084== ERROR: AddressSanitizer: stack-buffer-underflow on address 0x7fffaa2c43e0 at pc 0x7f3c76db0ac2 bp 0x7fffaa2c3ee0 sp 0x7fffaa2c3ed8
READ of size 8 at 0x7fffaa2c43e0 thread T0
    #0 0x7f3c76db0ac1 (/scratch/repos/ruby/miniruby+0x11eac1)
    #1 0x7f3c76db0cba (/scratch/repos/ruby/miniruby+0x11ecba)
    #2 0x7f3c76db2ab0 (/scratch/repos/ruby/miniruby+0x120ab0)
    #3 0x7f3c76db3a8e (/scratch/repos/ruby/miniruby+0x121a8e)
    #4 0x7f3c76db52ab (/scratch/repos/ruby/miniruby+0x1232ab)
    #5 0x7f3c76f1a668 (/scratch/repos/ruby/miniruby+0x288668)
    #6 0x7f3c76dd1d82 (/scratch/repos/ruby/miniruby+0x13fd82)
    #7 0x7f3c76e50df4 (/scratch/repos/ruby/miniruby+0x1bedf4)
    #8 0x7f3c76e6fb3d (/scratch/repos/ruby/miniruby+0x1ddb3d)
    #9 0x7f3c7700b86b (/scratch/repos/ruby/miniruby+0x37986b)
    #10 0x7f3c76e2e3a4 (/scratch/repos/ruby/miniruby+0x19c3a4)
    #11 0x7f3c76efa3f0 (/scratch/repos/ruby/miniruby+0x2683f0)
    #12 0x7f3c76d8a68d (/scratch/repos/ruby/miniruby+0xf868d)
    #13 0x7f3c76ef9fae (/scratch/repos/ruby/miniruby+0x267fae)
    #14 0x7f3c76d8c44e (/scratch/repos/ruby/miniruby+0xfa44e)
    #15 0x7f3c76d8f816 (/scratch/repos/ruby/miniruby+0xfd816)
    #16 0x7f3c76fc7b37 (/scratch/repos/ruby/miniruby+0x335b37)
    #17 0x7f3c76fff525 (/scratch/repos/ruby/miniruby+0x36d525)
    #18 0x7f3c76fd9f69 (/scratch/repos/ruby/miniruby+0x347f69)
    #19 0x7f3c76fe7986 (/scratch/repos/ruby/miniruby+0x355986)
    #20 0x7f3c76fec907 (/scratch/repos/ruby/miniruby+0x35a907)
    #21 0x7f3c76d83de1 (/scratch/repos/ruby/miniruby+0xf1de1)
    #22 0x7f3c76d88dec (/scratch/repos/ruby/miniruby+0xf6dec)
    #23 0x7f3c76d0ad98 (/scratch/repos/ruby/miniruby+0x78d98)
    #24 0x7f3c725a8b74 (/usr/lib64/libc-2.17.so+0x21b74)
    #25 0x7f3c76d0b6d0 (/scratch/repos/ruby/miniruby+0x796d0)
Address 0x7fffaa2c43e0 is located at offset 0 in frame <rb_io_getline_1> of T0's stack:
  This frame has 1 object(s):
    [32, 36) 'cr'
...
make: *** [.rbconfig.time] Error 1

Decoding the above trace gives us, 

=================================================================
==12684== ERROR: AddressSanitizer: stack-buffer-underflow on address 0x7fff4ec9f180 at pc 0x7ff3ce5e6ac2 bp 0x7fff4ec9ec80 sp 0x7fff4ec9ec78
READ of size 8 at 0x7fff4ec9f180 thread T0
    #0 0x7ff3ce5e6ac1 in mark_locations_array /scratch/repos/ruby/gc.c:2682
    #1 0x7ff3ce5e6cba in gc_mark_locations /scratch/repos/ruby/gc.c:2693
    #2 0x7ff3ce5e8ab0 in gc_marks_body /scratch/repos/ruby/gc.c:3419
    #3 0x7ff3ce5e9a8e in gc_marks /scratch/repos/ruby/gc.c:3653
    #4 0x7ff3ce5eb2ab in heap_prepare_freeslot /scratch/repos/ruby/gc.c:906
    #5 0x7ff3ce750668 in str_alloc /scratch/repos/ruby/string.c:384
    #6 0x7ff3ce607d82 in rb_io_getline_fast /scratch/repos/ruby/io.c:2902
    #7 0x7ff3ce686df4 in lex_getline /scratch/repos/ruby/parse.y:5416
    #8 0x7ff3ce6a5b3d in yycompile0 /scratch/repos/ruby/parse.y:5347
    #9 0x7ff3ce84186b in rb_suppress_tracing /scratch/repos/ruby/vm_trace.c:367
    #10 0x7ff3ce6643a4 in yycompile /scratch/repos/ruby/parse.y:5379
    #11 0x7ff3ce7303f0 in load_file_internal /scratch/repos/ruby/ruby.c:1728
    #12 0x7ff3ce5c068d in rb_ensure /scratch/repos/ruby/eval.c:820
    #13 0x7ff3ce72ffae in load_file /scratch/repos/ruby/ruby.c:1765
    #14 0x7ff3ce5c244e in rb_load_internal /scratch/repos/ruby/load.c:594 (discriminator 3)
    #15 0x7ff3ce5c5816 in rb_require_safe /scratch/repos/ruby/load.c:958
    #16 0x7ff3ce7fdb37 in vm_call_cfunc_with_frame /scratch/repos/ruby/vm_insnhelper.c:1493
    #17 0x7ff3ce835525 in vm_call_cfunc /scratch/repos/ruby/vm_insnhelper.c:1583
    #18 0x7ff3ce80ff69 in vm_exec_core /scratch/repos/ruby/insns.def:1017
    #19 0x7ff3ce81d986 in vm_exec /scratch/repos/ruby/vm.c:1198
    #20 0x7ff3ce822907 in rb_iseq_eval_main /scratch/repos/ruby/vm.c:1448
    #21 0x7ff3ce5b9de1 in ruby_exec_internal /scratch/repos/ruby/eval.c:252 (discriminator 1)
    #22 0x7ff3ce5bedec in ruby_exec_node /scratch/repos/ruby/eval.c:317
    #23 0x7ff3ce540d98 in main /scratch/repos/ruby/main.c:36
    #24 0x7ff3c9ddeb74 in ?? ??:0
    #25 0x7ff3ce5416d0 in _start ??:?

...

Is this expected behaviour? Can we patch ruby to be a bit more friendly towards AddressSanitizer?

This "problem" exists in older versions too (e.g. ruby-2.0.0-p247).




-- 
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