@_ is pre-allocated for every sub

[p5pRT]

Migrated from rt.perl.org#72416 (status was 'resolved')

Searchable as RT72416$

[p5pRT]

From @nwc10

Body was too large for import. Click here for the attachment in RT

[p5pRT]

From @nwc10

Applied as 77bac22.

[p5pRT]

From [Unknown Contact. See original ticket]

Applied as 77bac22.

[p5pRT]

@nwc10 - Status changed from 'new' to 'resolved'

[p5pRT]

From @avar

On Sun, May 30, 2010 at 10​:56, Nicholas Clark via RT
<perlbug-comment@​perl.org> wrote​:

Applied as 77bac22.

This caused a regression in v5.13.1..v5.13.2 when running
DBD​::SQLite's tests. Its t/13_create_collation.t test now segfaults
using DBI 1.611 (for perl 5.013002 on x86_64-linux).
http​://gist.github.com/449891 is the script I used to bisect it.

(gdb) run -Mblib t/13_create_collation.t
Starting program​: /tmp/perl/bin/perl5.13.1 -Mblib t/13_create_collation.t
1..25
ok 1 - can't override builtin perl collation
ok 2 - can't delete builtin perl collation
ok 3 - can't override registered collation
ok 4 - overridden collation
ok 5 - The object isa DBI​::db
ok 6 - collate perl (Bergere, Berg��e, HAT, HOT, berger, berg��e,
ferme, f��e, f��u, f��e, h��er, h��aut, h��a��e, h����oclite, h��re,
h��e // Bergere, Berg��e, HAT, HOT, berger, berg��e, ferme, f��e,
f��u, f��e, h��er, h��aut, h��a��e, h����oclite, h��re, h��e)
ok 7 - collate perllocale (berg��e, Berg��e, berger, Bergere, f��e,
f��e, ferme, f��u, h��a��e, HAT, h��aut, h��e, h��er, h����oclite,
HOT, h��re // berg��e, Berg��e, berger, Bergere, f��e, f��e, ferme,
f��u, h��a��e, HAT, h��aut, h��e, h��er, h����oclite, HOT, h��re)

Program received signal SIGSEGV, Segmentation fault.
0x00007ffff70257f7 in memcpy () from /lib/libc.so.6
(gdb) bt full
#0 0x00007ffff70257f7 in memcpy () from /lib/libc.so.6
No symbol table info available.
#1 0x0000000000488839 in Perl_pp_entersub ()
No symbol table info available.
#2 0x0000000000433b66 in Perl_call_sv ()
No symbol table info available.
#3 0x00007fffefd2cc55 in sqlite_db_collation_dispatcher () from
/tmp/DBD-SQLite-1.30_03/blib/arch/auto/DBD/SQLite/SQLite.so
No symbol table info available.
#4 0x00007fffefd312b1 in sqlite_db_create_collation () from
/tmp/DBD-SQLite-1.30_03/blib/arch/auto/DBD/SQLite/SQLite.so
#5 0x00007fffefd2b6e6 in XS_DBD__SQLite__db_create_collation () from
/tmp/DBD-SQLite-1.30_03/blib/arch/auto/DBD/SQLite/SQLite.so
No symbol table info available.
#6 0x00007ffff03d7de3 in XS_DBI_dispatch () from
/tmp/perl/lib/site_perl/5.13.1/x86_64-linux/auto/DBI/DBI.so
No symbol table info available.
#7 0x0000000000488a22 in Perl_pp_entersub ()
No symbol table info available.
#8 0x00000000004873a3 in Perl_runops_standard ()
No symbol table info available.
#9 0x0000000000433711 in Perl_call_sv ()
No symbol table info available.
#10 0x00007fffefd2c560 in sqlite_db_collation_needed_dispatcher ()
from /tmp/DBD-SQLite-1.30_03/blib/arch/auto/DBD/SQLite/SQLite.so
No symbol table info available.
#11 0x00007fffefd5cd5b in sqlite3GetCollSeq () from
/tmp/DBD-SQLite-1.30_03/blib/arch/auto/DBD/SQLite/SQLite.so
No symbol table info available.
#12 0x00007fffefd5dab1 in sqlite3LocateCollSeq () from
/tmp/DBD-SQLite-1.30_03/blib/arch/auto/DBD/SQLite/SQLite.so
No symbol table info available.
#13 0x00007fffefd5e910 in sqlite3ExprSetColl () from
/tmp/DBD-SQLite-1.30_03/blib/arch/auto/DBD/SQLite/SQLite.so
No symbol table info available.
#14 0x00007fffefd78abd in sqlite3Parser () from
/tmp/DBD-SQLite-1.30_03/blib/arch/auto/DBD/SQLite/SQLite.so
No symbol table info available.
#15 0x00007fffefd7988f in sqlite3RunParser () from
/tmp/DBD-SQLite-1.30_03/blib/arch/auto/DBD/SQLite/SQLite.so
No symbol table info available.
#16 0x00007fffefd7b9c4 in sqlite3Prepare () from
/tmp/DBD-SQLite-1.30_03/blib/arch/auto/DBD/SQLite/SQLite.so
No symbol table info available.
#17 0x00007fffefd7bc5a in sqlite3LockAndPrepare () from
/tmp/DBD-SQLite-1.30_03/blib/arch/auto/DBD/SQLite/SQLite.so
No symbol table info available.
---Type <return> to continue, or q <return> to quit---
#18 0x00007fffefd7be98 in sqlite3_prepare_v2 () from
/tmp/DBD-SQLite-1.30_03/blib/arch/auto/DBD/SQLite/SQLite.so
No symbol table info available.
#19 0x00007fffefd300b8 in sqlite_st_prepare () from
/tmp/DBD-SQLite-1.30_03/blib/arch/auto/DBD/SQLite/SQLite.so
No symbol table info available.
#20 0x00007fffefd27375 in XS_DBD__SQLite__st__prepare () from
/tmp/DBD-SQLite-1.30_03/blib/arch/auto/DBD/SQLite/SQLite.so
No symbol table info available.
#21 0x0000000000488a22 in Perl_pp_entersub ()
No symbol table info available.
#22 0x00000000004873a3 in Perl_runops_standard ()
No symbol table info available.
#23 0x0000000000433711 in Perl_call_sv ()
No symbol table info available.
#24 0x00007ffff03d5fcd in XS_DBI_dispatch () from
/tmp/perl/lib/site_perl/5.13.1/x86_64-linux/auto/DBI/DBI.so
No symbol table info available.
#25 0x0000000000488a22 in Perl_pp_entersub ()
No symbol table info available.
#26 0x00000000004873a3 in Perl_runops_standard ()
No symbol table info available.
#27 0x0000000000433711 in Perl_call_sv ()
No symbol table info available.
#28 0x00007ffff03d5fcd in XS_DBI_dispatch () from
/tmp/perl/lib/site_perl/5.13.1/x86_64-linux/auto/DBI/DBI.so
No symbol table info available.
#29 0x0000000000488a22 in Perl_pp_entersub ()
No symbol table info available.
#30 0x00000000004873a3 in Perl_runops_standard ()
No symbol table info available.
#31 0x00000000004341b1 in perl_run ()
No symbol table info available.
#32 0x000000000042072c in main ()
No symbol table info available.

[p5pRT]

From @nwc10

On Wed, Jun 23, 2010 at 01​:20​:11PM +0000, Ævar Arnfjörð Bjarmason wrote​:

On Sun, May 30, 2010 at 10​:56, Nicholas Clark via RT
<perlbug-comment@​perl.org> wrote​:

Applied as 77bac22.

This caused a regression in v5.13.1..v5.13.2 when running
DBD​::SQLite's tests. Its t/13_create_collation.t test now segfaults
using DBI 1.611 (for perl 5.013002 on x86_64-linux).
http​://gist.github.com/449891 is the script I used to bisect it.

Aha. That seems to be bug 72334.
I've applied Gerrard's patch as 8f443ca
and that seems to fix this.

Nicholas Clark