Hi once more:I've installed a mod_perl compiled with MP_DEBUG=1 and obtained a core file, from which I get this stack trace when loading Carp.pm. It seems it segfaults when compiling the regular expression from this line in Carp.pm:
is_utf8($arg) or $arg =~
s/([[:cntrl:]]|[[:^ascii:]])/sprintf("\\x{%x}",ord($1))/eg;
Does this help at all?
Regards,
Doug Hunt
-------------------%<--------------------------------------------
(gdb) where
#0 0x0000000000513346 in Perl__invlist_union_maybe_complement_2nd ()
#1 0x000000000051642d in S_regclass ()
#2 0x0000000000518e38 in S_regpiece ()
#3 0x000000000051ab30 in S_regbranch ()
#4 0x000000000051ae2d in S_reg ()
#5 0x0000000000518dae in S_regpiece ()
#6 0x000000000051ab30 in S_regbranch ()
#7 0x000000000051ae2d in S_reg ()
#8 0x000000000051dadc in Perl_re_compile ()
#9 0x00000000004d2d24 in Perl_pmruntime ()
#10 0x0000000000506404 in Perl_yyparse ()
#11 0x00000000005721b0 in S_doeval ()
#12 0x0000000000573ea9 in Perl_pp_require ()
#13 0x0000000000489ee1 in modperl_pp_require ()
#14 0x000000000053fc93 in Perl_runops_standard ()
#15 0x00000000004dd0c3 in Perl_eval_sv ()
#16 0x000000000047c3de in modperl_require_module (pv=0x1b8a498 "Carp",
logfailure=1)
#17 0x0000000000475e6d in modperl_config_apply_PerlModule (s=0x1b68950,
scfg=0x1b6ca00, perl=0x1beeb10, p=0x1b5f138)
#18 0x000000000047322f in modperl_startup (s=0x1b68950, p=0x1b5f138) #19 0x0000000000472ee2 in modperl_startup (s=0x1b68950, p=0x1b5f138)#20 0x000000000047415b in modperl_init (base_server=0x1b68950, p=0x1b5f138) #21 0x0000000000474484 in modperl_hook_init (pconf=0x1b5f138, plog=0x1ba5368, ptemp=0x1b69188, s=0x1b68950)
#22 0x0000000000464701 in ap_run_open_logs () #23 0x000000000044abed in main () ----------------------%<------------------------------------------------- dh...@ucar.edu Software Engineer UCAR - COSMIC, Tel. (303) 497-2611 On Mon, 20 Aug 2012, Doug Hunt wrote:
Hi Fred, modperl folks:We've narrowed down this bug a bit more. We are currently running perl 5.16.1 (latest), the latest mod_perl from source and apache version 2.2.22.If we run a simple httpd.conf with this line: PerlModule Carp Then single-process startup will fail on the second perl startup.(perl starts up twice when apache is started, as explained in http://perl.apache.org/docs/2.0/user/handlers/server.html).httpd -X (segmentation fault)We can tell that apache starts up perl successfully the first time by running strace. The segfault can be traced to one line in Carp.pm:--------------------%<---------------------------------------------------- # Transform an argument to a function into a string. sub format_arg { ... # The following handling of "control chars" is direct from # the original code - it is broken on Unicode though. # Suggestions?is_utf8($arg) or $arg =~ s/([[:cntrl:]]|[[:^ascii:]])/sprintf("\\x{%x}",ord($1))/eg;return $arg; } --------------------%<-------------------------------------------------------If we comment out the line which starts 'is_utf8...' then the segfault is prevented. It strikes me as odd that just *compiling* that line (which is legal perl) should cause a segfault, but that is what we repeatedly observe.Any ideas or thoughts welcome! Regards, Doug Hunt dh...@ucar.edu Software Engineer UCAR - COSMIC, Tel. (303) 497-2611 On Tue, 14 Aug 2012, Fred Moyer wrote:Can you try the latest version from source? http://perl.apache.org/download/source.html It looks like you are using perl 5.16, some recent fixes were committed there. The subversion tip will likely be the 2.0.8 RC in a week or so. On Mon, Aug 13, 2012 at 3:01 PM, Jason Lin <jason...@ucar.edu> wrote:Hi, I work for a project that has been using mod_perl for quite a while. Recently, we upgraded our 64-bit web server with Perl 5.16, mod_perl 2.0.7(it's 2.0.6 with patch), and apache 2.2.22 on CentOS 6.3. Since then, we'vebeen unable to start Apache server (segmentation faults) with same httpd.conf which worked previously. As far as I can tell, the segfault seems to be triggered while trying toload any Perl module using either PerlModule directive or in <Perl> block inhttpd.conf that directly or indirectly use Carp, or even just try to loadCarp itself. Strace shows that the process would segfault while loading (orright after loading) Carp.pm. The server can still successfully start and work when carefully removing such modules in httpd.conf.Is anyone seeing this same issue or have any ideas how it can be fixed otherthan trying to hack through all the Perl modules to make sure Carp is not called? perl -V Summary of my perl5 (revision 5 version 16 subversion 0) configuration: Platform: osname=linux, osvers=2.6.32-279.1.1.el6.x86_64, archname=x86_64-linux uname='linux fox.cosmic.ucar.edu 2.6.32-279.1.1.el6.x86_64 #1 smp tue jul 10 13:47:21 utc 2012 x86_64 x86_64 x86_64 gnulinux ' config_args='-Dprefix=/ops/tools -des -Accflags=-DPERL_RELOCATABLE_INCPUSH' hint=recommended, useposix=true, d_sigaction=define useithreads=undef, usemultiplicity=undef useperlio=define, d_sfio=undef, uselargefiles=define, usesocks=undef use64bitint=define, use64bitall=define, uselongdouble=undef usemymalloc=n, bincompat5005=undef Compiler:cc='cc', ccflags ='-DPERL_RELOCATABLE_INCPUSH -fno-strict-aliasing -pipe-fstack-protector -I/usr/local/include -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64', optimize='-O2', cppflags='-DPERL_RELOCATABLE_INCPUSH -fno-strict-aliasing -pipe -fstack-protector -I/usr/local/include' ccversion='', gccversion='4.4.6 20120305 (Red Hat 4.4.6-4)', 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='cc', ldflags =' -fstack-protector -L/usr/local/lib' libpth=/usr/local/lib /lib/../lib64 /usr/lib/../lib64 /lib /usr/lib /lib64 /usr/lib64 /usr/local/lib64 libs=-lnsl -lgdbm -ldl -lm -lcrypt -lutil -lc perllibs=-lnsl -ldl -lm -lcrypt -lutil -lc libc=, so=so, useshrplib=false, libperl=libperl.a gnulibc_version='2.12' Dynamic Linking: dlsrc=dl_dlopen.xs, dlext=so, d_dlsymun=undef, ccdlflags='-Wl,-E' cccdlflags='-fPIC', lddlflags='-shared -O2 -L/usr/local/lib -fstack-protector' Characteristics of this binary (from libperl): Compile-time options: HAS_TIMES PERLIO_LAYERS PERL_DONT_CREATE_GVSV PERL_MALLOC_WRAP PERL_PRESERVE_IVUV PERL_RELOCATABLE_INCPUSH USE_64_BIT_ALL USE_64_BIT_INT USE_LARGE_FILES USE_LOCALE USE_LOCALE_COLLATE USE_LOCALE_CTYPE USE_LOCALE_NUMERIC USE_PERLIO USE_PERL_ATOF Built under linux Compiled at Aug 1 2012 16:14:39 %ENV: PERL5LIB="/ops/tools/lib" @INC: /ops/tools/lib /ops/tools/lib/perl5/site_perl/5.16.0/x86_64-linux /ops/tools/lib/perl5/site_perl/5.16.0 /ops/tools/lib/perl5/5.16.0/x86_64-linux /ops/tools/lib/perl5/5.16.0 .Note that we compiled Perl with relocation flag (-DPERL_RELOCATABLE_INCPUSH)turned on, yet same issue can also be found without the flag in our test. Any help/advice would be appreciated, thank you in advance. Best, Jason
