Perl RPM upgrade breaks alarm() on SuSE-9.1-i386

ndwg has asked for the wisdom of the Perl Monks concerning the following question:

Greetings Monks,

I'm looking for guidance on why upgrading a Perl RPM would have broken alarm() functionality, and what to do to fix it.

On a SuSE Linux 9.1 (i586) system, with the latest available perl RPM installed (perl-5.8.3-32.9.i586.rpm), the test code below does not work as expected. The script should print the numbers 1 through 5, catch the alarm, and exit. However, it continues looping until killed with CTRL-C.

The test code works as expected on multiple other platforms and perl versions, including "SuSE Linux 9.1 (x86-64)" with the same perl RPM version installed.

I am almost certain that this functionality worked with the original system install (perl-5.8.3-32.i586.rpm). Due to site security policies, and a published vulnerability in the original perl RPM, we are unable to downgrade perl to the original version. We would like to stick to vendor-supported RPMs, rather than building Perl from source... but SuSE doesn't seem to be supporting 9.1 any more.

Is there something wrong with my test case?
Is this a known problem?
Are there any workarounds?
What are the chances that the update RPM from SuSE-9.3 (perl-5.8.6-5.3.i586.rpm) will work with the other ~40 perl RPMs that are installed?

Thanks for your wisdom,
Nathan

------------------ perl_alarm_test.pl --------------------
#!/usr/bin/perl

my $time = shift;
defined $time or $time = 5;

$SIG{ALRM} = sub { $last = 1; };
$SIG{INT} = sub { $last = 1; };
alarm $time;

$last=0;
$index=0;
while ($last eq 0) {
    sleep 1;
    $index=$index+1;
    print "$index\n";
}
$SIG{INT} = undef;

exit;
-----------------------------------------------------------
[download]

Perl version information...

# perl -V
Summary of my perl5 (revision 5.0 version 8 subversion 3) configuratio
+n:
  Platform:
    osname=linux, osvers=2.6.4, archname=i586-linux-thread-multi
    uname='linux f195 2.6.4 #1 smp tue nov 29 14:32:29 utc 2005 i686 i
+686 i386 gnulinux '
    config_args='-ds -e -Dprefix=/usr -Dvendorprefix=/usr -Dinstallusr
+binperl -Dusethreads -Di_db -Di_dbm -Di_ndbm -Di_gdbm -Duseshrplib=tr
+ue -Doptimize=-O2 -march=i586 -mcpu=i686 -fmessage-length=0 -Wall -Wa
+ll -pipe'
    hint=recommended, useposix=true, d_sigaction=define
    usethreads=define use5005threads=undef useithreads=define usemulti
+plicity=define
    useperlio=define d_sfio=undef uselargefiles=define usesocks=undef
    use64bitint=undef use64bitall=undef uselongdouble=undef
    usemymalloc=n, bincompat5005=undef
  Compiler:
    cc='cc', ccflags ='-D_REENTRANT -D_GNU_SOURCE -DTHREADS_HAVE_PIDS 
+-fno-strict-aliasing -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64',
    optimize='-O2 -march=i586 -mcpu=i686 -fmessage-length=0 -Wall -Wal
+l -pipe',
    cppflags='-D_REENTRANT -D_GNU_SOURCE -DTHREADS_HAVE_PIDS -fno-stri
+ct-aliasing'
    ccversion='', gccversion='3.3.3 (SuSE Linux)', gccosandvers=''
    intsize=4, longsize=4, ptrsize=4, doublesize=8, byteorder=1234
    d_longlong=define, longlongsize=8, d_longdbl=define, longdblsize=1
+2
    ivtype='long', ivsize=4, nvtype='double', nvsize=8, Off_t='off_t',
+ lseeksize=8
    alignbytes=4, prototype=define
  Linker and Libraries:
    ld='cc', ldflags =''
    libpth=/lib /usr/lib /usr/local/lib
    libs=-lnsl -ldl -lm -lcrypt -lutil -lpthread -lc
    perllibs=-lnsl -ldl -lm -lcrypt -lutil -lpthread -lc
    libc=, so=so, useshrplib=true, libperl=libperl.so
    gnulibc_version='2.3.3'
  Dynamic Linking:
    dlsrc=dl_dlopen.xs, dlext=so, d_dlsymun=undef, ccdlflags='-rdynami
+c -Wl,-rpath,/usr/lib/perl5/5.8.3/i586-linux-thread-multi/CORE'
    cccdlflags='-fPIC', lddlflags='-shared'


Characteristics of this binary (from libperl):
  Compile-time options: MULTIPLICITY USE_ITHREADS USE_LARGE_FILES PERL
+_IMPLICIT_CONTEXT
  Locally applied patches:
        SPRINTF0 - fixes for sprintf formatting issues - CVE-2005-3962
  Built under linux
  Compiled at Dec 17 2005 03:22:07
  @INC:
    /usr/lib/perl5/5.8.3/i586-linux-thread-multi
    /usr/lib/perl5/5.8.3
    /usr/lib/perl5/site_perl/5.8.3/i586-linux-thread-multi
    /usr/lib/perl5/site_perl/5.8.3
    /usr/lib/perl5/site_perl
    /usr/lib/perl5/vendor_perl/5.8.3/i586-linux-thread-multi
    /usr/lib/perl5/vendor_perl/5.8.3
    /usr/lib/perl5/vendor_perl
    .

# rpm -qi perl-5.8.3-32.9
Name        : perl                         Relocations: (not relocatab
+le)
Version     : 5.8.3                             Vendor: SuSE Linux AG,
+ Nuernberg, Germany
Release     : 32.9                          Build Date: Sat Dec 17 03:
+32:43 2005
Install date: Mon Mar 12 17:55:19 2007      Build Host: f195.suse.de
Group       : Development/Languages/Perl    Source RPM: perl-5.8.3-32.
+9.src.rpm
Size        : 36585954                         License: GPL, Artistic 
+License
Signature   : DSA/SHA1, Sat Dec 17 03:34:46 2005, Key ID a84edae89c800
+aca
Packager    : http://www.suse.de/feedback
Summary     : The Perl interpreter
[download]

Comment on Perl RPM upgrade breaks alarm() on SuSE-9.1-i386 Select or Download Code

Replies are listed 'Best First'.
Re: Perl RPM upgrade breaks alarm() on SuSE-9.1-i386 by Anno (Deacon) on Mar 28, 2007 at 16:29 UTC
Is there something wrong with my test case? Yes, you're running without `strict` :) ~~In your `SIGINT` handler you are setting the variable `$main::last`. The loop queries the lecical `$last`.~~ Anno Update: Sorry, scratch it all. I saw a "`my`" declaration in your code where there was none.	[reply] [d/l] [select]
Re^2: Perl RPM upgrade breaks alarm() on SuSE-9.1-i386 by cmeyer (Pilgrim) on Mar 28, 2007 at 16:35 UTC
The user doesn't declare a lexical variable $last, so the while condition is looking at $main::last. I would recommend building your own perl and installing it in /usr/local, or some other location that will not interfere with the system's perl installation. It is easy (Configure -des; make test; sudo make install). Installing an rpm package that was built for a different version of the os is asking for trouble. -Colin. WHITEPAGES.COM \| INC	[reply]