usemymalloc cannot handle long strings

[p5pRT]

Migrated from rt.perl.org#119829 (status was 'resolved')

Searchable as RT119829$

[p5pRT]

From @cpansprout

usemymalloc cannot handle long strings

$ ./perl -Ilib -e 'my $x=" "x(${\2}**31+20);'
Segmentation fault​: 11

(gdb) bt
#0 0x000000010007ac70 in fill_pat_4bytes (s=0x1009eda00 "ޭ??ޭ??ޭ??ޭ??ޭ??ޭ??ޭ??ޭ??ޭ??ޭ??ޭ??ޭ??ޭ??ޭ??ޭ??ޭ??ޭ??ޭ??ޭ??ޭ??ޭ??ޭ??ޭ??ޭ??ޭ??ޭ??ޭ??ޭ??ޭ??ޭ??ޭ??ޭ??ޭ??ޭ??ޭ??ޭ??ޭ??ޭ??ޭ??ޭ??ޭ??ޭ??ޭ??ޭ??ޭ??ޭ??ޭ??ޭ??ޭ??ޭ??"..., nbytes=2147487744, fill=0x1004a9840 "ޭ??ޭ??ޭ??ޭ??????????????????AUTOLOAD") at malloc.c​:1158
#1 0x000000010007a51f in morecore (bucket=31) at malloc.c​:1772
#2 0x00000001000793ec in Perl_malloc (nbytes=2147479588) at malloc.c​:1287
#3 0x000000010007bcd7 in Perl_realloc (mp=0x1009a9468, nbytes=2147483670) at malloc.c​:2097
#4 0x000000010025d62c in Perl_sv_grow (my_perl=0x100803200, sv=0x100997460, newlen=2147483670) at sv.c​:1532
#5 0x000000010030b6b7 in Perl_pp_repeat (my_perl=0x100803200) at pp.c​:1729
#6 0x00000001001b016c in Perl_runops_debug (my_perl=0x100803200) at dump.c​:2261
#7 0x0000000100060702 in S_run_body (my_perl=0x100803200, oldscope=1) at perl.c​:2500
#8 0x000000010005f6d5 in perl_run (my_perl=0x100803200) at perl.c​:2416
#9 0x0000000100001428 in main (argc=3, argv=0x7fff5fbffa80, env=0x7fff5fbffaa0) at perlmain.c​:112

For me, it happens with any number larger than 1073745906.

$ ./perl -Ilib -e 'my $x=" "x 1073745907'
Segmentation fault​: 11

I am also compiling with mad+threads, if that makes any difference.

Summary of my perl5 (revision 5 version 19 subversion 3) configuration​:
  Commit id​: a496ca38c9dd66846ae327cc193078aee36ae004
  Platform​:
  osname=darwin, osvers=12.2.0, archname=darwin-thread-multi-2level
  uname='darwin pint.local 12.2.0 darwin kernel version 12.2.0​: sat aug 25 00​:48​:52 pdt 2012; root​:xnu-2050.18.24~1release_x86_64 x86_64 '
  config_args='-Dusemymalloc -Duseithreads -Dmad -de -Dusedevel -Doptimize=-ggdb3 -Aoptimize=-O0 -DDEBUGGING'
  hint=recommended, useposix=true, d_sigaction=define
  useithreads=define, usemultiplicity=define
  useperlio=define, d_sfio=undef, uselargefiles=define, usesocks=undef
  use64bitint=define, use64bitall=define, uselongdouble=undef
  usemymalloc=y, bincompat5005=undef
  Compiler​:
  cc='cc', ccflags ='-fno-common -DPERL_DARWIN -DDEBUGGING -fno-strict-aliasing -pipe -fstack-protector -I/usr/local/include',
  optimize='-ggdb3 -O0',
  cppflags='-fno-common -DPERL_DARWIN -DDEBUGGING -fno-strict-aliasing -pipe -fstack-protector -I/usr/local/include'
  ccversion='', gccversion='4.2.1 Compatible Apple LLVM 4.2 (clang-425.0.27)', gccosandvers=''
  intsize=4, longsize=8, ptrsize=8, doublesize=8, byteorder=12345678
  d_longlong=define, longlongsize=8, d_longdbl=define, longdblsize=16
  ivtype='long', ivsize=8, nvtype='double', nvsize=8, Off_t='off_t', lseeksize=8
  alignbytes=8, prototype=define
  Linker and Libraries​:
  ld='env MACOSX_DEPLOYMENT_TARGET=10.3 cc', ldflags =' -fstack-protector -L/usr/local/lib'
  libpth=/usr/local/lib /usr/lib
  libs=-ldbm -ldl -lm -lutil -lc
  perllibs=-ldl -lm -lutil -lc
  libc=, so=dylib, useshrplib=false, libperl=libperl.a
  gnulibc_version=''
  Dynamic Linking​:
  dlsrc=dl_dlopen.xs, dlext=bundle, d_dlsymun=undef, ccdlflags=' '
  cccdlflags=' ', lddlflags=' -bundle -undefined dynamic_lookup -L/usr/local/lib -fstack-protector'

Characteristics of this binary (from libperl)​:
  Compile-time options​: DEBUGGING HAS_TIMES MULTIPLICITY MYMALLOC
  PERLIO_LAYERS PERL_DONT_CREATE_GVSV
  PERL_HASH_FUNC_ONE_AT_A_TIME_HARD
  PERL_IMPLICIT_CONTEXT PERL_MAD PERL_MALLOC_WRAP
  PERL_NEW_COPY_ON_WRITE PERL_PRESERVE_IVUV
  PERL_TRACK_MEMPOOL PERL_USE_DEVEL USE_64_BIT_ALL
  USE_64_BIT_INT USE_ITHREADS USE_LARGE_FILES
  USE_LOCALE USE_LOCALE_COLLATE USE_LOCALE_CTYPE
  USE_LOCALE_NUMERIC USE_PERLIO USE_PERL_ATOF
  USE_REENTRANT_API
  Built under darwin
  Compiled at Aug 11 2013 14​:54​:13
  @​INC​:
  lib
  /usr/local/lib/perl5/site_perl/5.19.3/darwin-thread-multi-2level
  /usr/local/lib/perl5/site_perl/5.19.3
  /usr/local/lib/perl5/5.19.3/darwin-thread-multi-2level
  /usr/local/lib/perl5/5.19.3
  /usr/local/lib/perl5/site_perl
  .

[p5pRT]

From zefram@fysh.org

Fixed in commit 64072da.

-zefram

[p5pRT]

The RT System itself - Status changed from 'new' to 'open'

[p5pRT]

@cpansprout - Status changed from 'open' to 'resolved'