From: Tanaka Akira <akr@...>
Date: 2007-07-08T09:43:32+09:00
Subject: [ruby-dev:31163] Invalid read of size 4: valgrind ./ruby -ve 'print "a"'

以下のようにすると、rb_thread_alone で
Invalid read of size 4 になるようです。

% valgrind ./ruby -ve 'print "a"'
==25885== Memcheck, a memory error detector.
==25885== Copyright (C) 2002-2006, and GNU GPL'd, by Julian Seward et al.
==25885== Using LibVEX rev 1658, a library for dynamic binary translation.
==25885== Copyright (C) 2004-2006, and GNU GPL'd, by OpenWorks LLP.
==25885== Using valgrind-3.2.1-Debian, a dynamic binary instrumentation framework.
==25885== Copyright (C) 2000-2006, and GNU GPL'd, by Julian Seward et al.
==25885== For more details, rerun with: -v
==25885== 
--25885-- DWARF2 CFI reader: unhandled CFI instruction 0:50
--25885-- DWARF2 CFI reader: unhandled CFI instruction 0:50
--25885-- DWARF2 CFI reader: unhandled CFI instruction 0:50
--25885-- DWARF2 CFI reader: unhandled CFI instruction 0:50
ruby 1.9.0 (2007-07-07 patchlevel 0) [i686-linux]
==25885== Invalid read of size 4
==25885==    at 0x80F46FF: rb_thread_alone (thread.c:1464)
==25885==    by 0x80F3A84: rb_thread_schedule (thread.c:601)
==25885==    by 0x80F3CF6: rb_thread_execute_interrupts (thread.c:710)
==25885==    by 0x80F313C: set_unblock_function (thread.c:194)
==25885==    by 0x80F4B94: do_select (thread.c:1716)
==25885==    by 0x80F4D02: rb_thread_wait_fd_rw (thread.c:1764)
==25885==    by 0x80F4D6E: rb_thread_fd_writable (thread.c:1786)
==25885==    by 0x806398C: io_fflush (io.c:421)
==25885==    by 0x80667A6: fptr_finalize (io.c:2212)
==25885==    by 0x8066898: rb_io_fptr_cleanup (io.c:2244)
==25885==    by 0x806691F: rb_io_fptr_finalize (io.c:2258)
==25885==    by 0x8062D96: rb_gc_call_finalizer_at_exit (gc.c:1987)
==25885==  Address 0x42EF8A0 is 8 bytes inside a block of size 16 free'd
==25885==    at 0x401CFA5: free (vg_replace_malloc.c:233)
==25885==    by 0x80C4BDE: st_free_table (st.c:215)
==25885==    by 0x80F1BF1: vm_free (yarvcore.c:153)
==25885==    by 0x8062D79: rb_gc_call_finalizer_at_exit (gc.c:1983)
==25885==    by 0x80599D3: ruby_finalize_1 (eval.c:146)
==25885==    by 0x8059ABA: ruby_cleanup (eval.c:178)
==25885==    by 0x8059CE5: ruby_run_node (eval.c:250)
==25885==    by 0x8056E54: main (main.c:46)
a==25885== 
==25885== ERROR SUMMARY: 1 errors from 1 contexts (suppressed: 19 from 1)
==25885== malloc/free: in use at exit: 881,496 bytes in 7,028 blocks.
==25885== malloc/free: 7,126 allocs, 98 frees, 896,747 bytes allocated.
==25885== For counts of detected errors, rerun with: -v
==25885== searching for pointers to 7,028 not-freed blocks.
==25885== checked 649,704 bytes.
==25885== 
==25885== LEAK SUMMARY:
==25885==    definitely lost: 0 bytes in 0 blocks.
==25885==      possibly lost: 68 bytes in 1 blocks.
==25885==    still reachable: 881,428 bytes in 7,027 blocks.
==25885==         suppressed: 0 bytes in 0 blocks.
==25885== Reachable blocks (those to which a pointer was found) are not shown.
==25885== To see them, rerun with: --show-reachable=yes
-- 
[田中 哲][たなか あきら][Tanaka Akira]