Wed Oct 17 13:55:55 2012: Request 80217 was acted upon.
Transaction: Correspondence added by BULKDD
Queue: Win32-API
Subject: Build failure under Cygwin on Windows
Broken in: 0.72
Severity: Critical
Owner: Nobody
Requestors: jdhed...@cpan.org
Status: open
Ticket <URL: https://rt.cpan.org/Ticket/Display.html?id=80217 >
On Wed Oct 17 11:48:44 2012, rur...@x-ray.at wrote:
> I can fully reproduce the errors.
As you said on IRC the problem is alloca. I installed a Cygwin Perl.
$ perl -V
Summary of my perl5 (revision 5 version 14 subversion 2) configuration:
Platform:
osname=cygwin, osvers=1.7.15(0.26053),
archname=cygwin-thread-multi-64int
uname='cygwin_nt-5.1 winxp 1.7.15(0.26053) 2012-05-09 10:25 i686
cygwin '
config_args='-de -Dlibperl=cygperl5_14.dll -Dcc=gcc-4 -Dld=g++-4
-Darchname=i686-cygwin-threads-64int -Dmksymlinks -Dusethreads -Accflags=-g'
hint=recommended, useposix=true, d_sigaction=define
useithreads=define, usemultiplicity=define
useperlio=define, d_sfio=undef, uselargefiles=define, usesocks=undef
use64bitint=define, use64bitall=undef, uselongdouble=undef
usemymalloc=n, bincompat5005=undef
Compiler:
cc='gcc-4', ccflags ='-DPERL_USE_SAFE_PUTENV -U__STRICT_ANSI__ -g
-fno-strict-aliasing -pipe -fstack-protector',
optimize='-O3',
cppflags='-DPERL_USE_SAFE_PUTENV -U__STRICT_ANSI__ -g
-fno-strict-aliasing -pipe -fstack-protector'
ccversion='', gccversion='4.5.3', gccosandvers=''
intsize=4, longsize=4, ptrsize=4, doublesize=8, byteorder=12345678
d_longlong=define, longlongsize=8, d_longdbl=define, longdblsize=12
ivtype='long long', ivsize=8, nvtype='double', nvsize=8,
Off_t='off_t', lseeksize=8
alignbytes=8, prototype=define
Linker and Libraries:
ld='g++-4', ldflags =' -Wl,--enable-auto-import
-Wl,--export-all-symbols -Wl,--enable-auto-image-base -fstack-protector
-L/usr/local/lib'
libpth=/usr/local/lib /usr/lib /lib
libs=-lgdbm -ldb -ldl -lcrypt -lgdbm_compat
perllibs=-ldl -lcrypt
libc=/usr/lib/libc.a, so=dll, useshrplib=true, libperl=cygperl5_14.dll
gnulibc_version=''
Dynamic Linking:
dlsrc=dl_dlopen.xs, dlext=dll, d_dlsymun=undef, ccdlflags=' '
cccdlflags=' ', lddlflags=' --shared -Wl,--enable-auto-import
-Wl,--export-all-symbols -Wl,--enable-auto-image-base -L/usr/local/lib
-fstack-protector'
Characteristics of this binary (from libperl):
Compile-time options: MULTIPLICITY PERL_DONT_CREATE_GVSV
PERL_IMPLICIT_CONTEXT PERL_PRESERVE_IVUV
PERL_USE_SAFE_PUTENV USE_64_BIT_INT USE_ITHREADS
USE_LARGE_FILES USE_PERLIO USE_PERL_ATOF
USE_REENTRANT_API
Locally applied patches:
Bug#55162 File::Spec::case_tolerant performance
CYG07 $vendorarch/auto/.rebase
CYG15 static Win32CORE
CYG17 cyg-1.7 paths-utf8
0c612ce82 Fix building static extensions on cygwin, -UUSEIMPORTLIB
1bac5ecc1 Fix 64-bit threading sv.c: S_anonymise_cv_maybe
Cygwin::sync_winenv added
Built under cygwin
Compiled at Jul 12 2012 14:17:21
%ENV:
PERL_JSON_BACKEND="JSON::XS"
PERL_YAML_BACKEND="YAML"
CYGWIN="tty"
@INC:
/usr/lib/perl5/site_perl/5.14/i686-cygwin-threads-64int
/usr/lib/perl5/site_perl/5.14
/usr/lib/perl5/vendor_perl/5.14/i686-cygwin-threads-64int
/usr/lib/perl5/vendor_perl/5.14
/usr/lib/perl5/5.14/i686-cygwin-threads-64int
/usr/lib/perl5/5.14
/usr/lib/perl5/site_perl/5.10
/usr/lib/perl5/vendor_perl/5.10
/usr/lib/perl5/site_perl/5.8
.
I got the same SEGV as others in this ticket said on benchmark.t. The
bug is limited to C funcs that Win32::API calls, that have more than 0
parameters, so this
https://metacpan.org/source/COSIMO/Win32-API-0.72/t/00_API.t#L46 didn't
crash, but 95% of everything else did. I used a assembly debugger (it
was faster for me, too much time to modify makefile.pl to include gdb
symbols), and what I think is the static linked in the DLL alloca,
returned in EAX (return value of alloca), the return instruction address
to right after the CALL alloca opcode, not a pointer to somewhere
near/in the C stack. The bug is towards the end of alloca since the
former return IP is read from the C stack into eax, then eax is pushed
on the c stack, then a retn to return. EAX now contains the return
instructionaddress (0x6E9E2772) while EBP is 0022AA48 and ESP is
0022A960 right before the retn opcode. This is a code generation problem
with Cygwin, not a problem with Win32::API. Here is what I think is
alloca is
6E9E4020 51 push ecx ; save ecx
6E9E4021 8D 4C 24 08 lea ecx,[esp+8]
6E9E4025 3D 00 10 00 00 cmp eax,1000h
6E9E402A 72 15 jb 6E9E4041
6E9E402C 81 E9 00 10 00 00 sub ecx,1000h
6E9E4032 83 09 00 or dword ptr [ecx],0
6E9E4035 2D 00 10 00 00 sub eax,1000h
6E9E403A 3D 00 10 00 00 cmp eax,1000h
6E9E403F 77 EB ja 6E9E402C
6E9E4041 29 C1 sub ecx,eax
6E9E4043 83 09 00 or dword ptr [ecx],0
6E9E4046 89 E0 mov eax,esp ;move orig esp to eax, our
new mem block
6E9E4048 89 CC mov esp,ecx ;move new sp to esp
6E9E404A 8B 08 mov ecx,dword ptr [eax]; restore ecx
from 6E9E4020
6E9E404C 8B 40 04 mov eax,dword ptr [eax+4] ;ret addr to
eax, and trash alloca-ed pointer
6E9E404F 50 push eax ;push eax on stack
6E9E4050 C3 ret ;pop off stack and jmp
