Here's an issue I've known about for several months but hadn't reported.
I'm curious if there are any ideas here for debugging or what the cause
might be (if obviously in Tcl.pm), or if I should go ahead and report it
to Debian package maintainers.
Christopher A. Chavez
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Using Debian 10 buster amd64, and packages provided by Debian:
perl 5.28.1-6
tk 8.6.9-2
tk-table 2.10-4 (borrowed from testing/bullseye; I can't find debug
symbols for 2.10-3)
plus Tcl.pm 1.27 (either Debian's libtcl-perl 1.27+ds-1, or from GitHub
master branch).
(I'm not sure which package might be responsible for this issue.
I believe I also observed this issue on a recent version of Ubuntu.)
Any normal usage of Tktable from Perl (e.g. with a wrapper like Tkx,
Tcl::Tk, or Tcl::pTk) will seem to work fine, but an error occurs when
the program is closed:
munmap_chunk(): invalid pointer
Aborted (core dumped)
This error does not occur when using Tktable directly from Tcl/Tk
(e.g. tclsh/wish), so I suspect the issue may be in Tcl.pm or Perl.
Example Perl script that exhibits the error:
use Tcl;
my $i = new Tcl;
$i->Init;
$i->Eval('package require Tk');
$i->Eval('package require Tktable');
$i->Eval('destroy .');
Valgrind indicates the error is due to an invalid free, but the exact
code responsible for the issue is unclear to me:
$ valgrind --num-callers=100 perl tktable-test.pl
==17734== Memcheck, a memory error detector
==17734== Copyright (C) 2002-2017, and GNU GPL'd, by Julian Seward et al.
==17734== Using Valgrind-3.14.0 and LibVEX; rerun with -h for copyright info
==17734== Command: perl -Mblib tktable-test.pl
...
[omitting "Invalid read of size 1" error -- known behavior when Tk
is loaded, https://core.tcl-lang.org/tk/tktview?name=e42eef33ee ]
...
==17734== Invalid free() / delete / delete[] / realloc()
==17734== at 0x48369AB: free (vg_replace_malloc.c:530)
==17734== by 0x162304: perl_destruct (in /usr/bin/perl)
==17734== by 0x13C3DB: main (in /usr/bin/perl)
==17734== Address 0x52012a0 is 8,400 bytes inside a block of size
16,384 alloc'd
==17734== at 0x483577F: malloc (vg_replace_malloc.c:299)
==17734== by 0x5550DFE: GetBlocks (tclThreadAlloc.c:1044)
==17734== by 0x5550549: TclpAlloc (tclThreadAlloc.c:358)
==17734== by 0x5459272: newstate (regc_nfa.c:135)
==17734== by 0x54548B8: parseqatom (regcomp.c:1136)
==17734== by 0x5453FA3: parsebranch (regcomp.c:760)
==17734== by 0x5453DF2: parse (regcomp.c:689)
==17734== by 0x545365E: TclReComp (regcomp.c:382)
==17734== by 0x5542841: CompileRegexp (tclRegexp.c:934)
==17734== by 0x5542404: Tcl_GetRegExpFromObj (tclRegexp.c:593)
==17734== by 0x547FCF4: Tcl_RegexpObjCmd (tclCmdMZ.c:268)
==17734== by 0x5467FB6: TclNRRunCallbacks (tclBasic.c:4461)
==17734== by 0x54693AE: TclEvalEx (tclBasic.c:5330)
==17734== by 0x5468D12: Tcl_EvalEx (tclBasic.c:4995)
==17734== by 0x54078CB: XS_Tcl_Eval (Tcl.xs:1097)
==17734== by 0x1F4360: Perl_pp_entersub (in /usr/bin/perl)
==17734== by 0x1EA685: Perl_runops_standard (in /usr/bin/perl)
==17734== by 0x166116: perl_run (in /usr/bin/perl)
==17734== by 0x13C401: main (in /usr/bin/perl)
==17734==
==17734== Invalid free() / delete / delete[] / realloc()
==17734== at 0x48369AB: free (vg_replace_malloc.c:530)
==17734== by 0x162322: perl_destruct (in /usr/bin/perl)
==17734== by 0x13C3DB: main (in /usr/bin/perl)
==17734== Address 0x536add0 is 8,720 bytes inside a block of size
16,384 alloc'd
==17734== at 0x483577F: malloc (vg_replace_malloc.c:299)
==17734== by 0x5550DFE: GetBlocks (tclThreadAlloc.c:1044)
==17734== by 0x5550549: TclpAlloc (tclThreadAlloc.c:358)
==17734== by 0x5471A87: Tcl_Alloc (tclCkalloc.c:1059)
==17734== by 0x5512900: AllocChannelBuffer (tclIO.c:2453)
==17734== by 0x5512900: GetInput (tclIO.c:6843)
==17734== by 0x5511B5C: DoReadChars (tclIO.c:5867)
==17734== by 0x5522605: TclNREvalFile (tclIOUtil.c:1920)
==17734== by 0x5480DE5: TclNRSourceObjCmd (tclCmdMZ.c:1013)
==17734== by 0x5467FB6: TclNRRunCallbacks (tclBasic.c:4461)
==17734== by 0x54693AE: TclEvalEx (tclBasic.c:5330)
==17734== by 0x5468D12: Tcl_EvalEx (tclBasic.c:4995)
==17734== by 0x54078CB: XS_Tcl_Eval (Tcl.xs:1097)
==17734== by 0x1F4360: Perl_pp_entersub (in /usr/bin/perl)
==17734== by 0x1EA685: Perl_runops_standard (in /usr/bin/perl)
==17734== by 0x166116: perl_run (in /usr/bin/perl)
==17734== by 0x13C401: main (in /usr/bin/perl)
