This is a bug report for perl from jvdias@xxxxxxxxxx, generated with the help of perlbug 1.35 running under perl v5.8.7. ----------------------------------------------------------------- [Please enter your report here] perl.h incorrectly guessed the IOCPARM_LEN on Linux to be constant 256 . The IOCPARM_LEN(ioctl_number) macro is meant to extract the length / size field from the ioctl_number, which must be the size of the memory pointed to by the pointer RW argument passed to ioctl. On Linux, the _IOC_SIZE(ioctl_number) macro is provided for this purpose, and there is no IOCPARM_LEN macro, so at pp_sys.c, in Perl_pp_ioctl, @line 2210: if (SvPOK(argsv) || !SvNIOK(argsv)) { STRLEN len; STRLEN need; s = SvPV_force(argsv, len); need = IOCPARM_LEN(func); if (len < need) { s = Sv_Grow(argsv, need + 1); SvCUR_set(argsv, need); } "need" was ALWAYS set to '257' on linux . ( BTW, shouldn't 'len' be initialized to 0 here? ) This bug was found to be the root cause of Red Hat Bugzilla #171111: https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=171111 where some printers would return a printer id string > 256 bytes long, which caused perl to generate a SIGSEGV in the ioctl(STDIN,0x84005001,$result) call, where $result was undef, because perl made $result only 257 bytes long. Here's a patch to perl.h which fixes this problem: --- perl-5.8.7/perl.h.IOC_SIZE 2005-05-07 16:11:45.000000000 -0400 +++ perl-5.8.7/perl.h 2005-10-25 16:56:10.000000000 -0400 @@ -2508,11 +2508,17 @@ #ifndef IOCPARM_LEN # ifdef IOCPARM_MASK - /* on BSDish systes we're safe */ + /* on BSDish systems we're safe */ # define IOCPARM_LEN(x) (((x) >> 16) & IOCPARM_MASK) # else - /* otherwise guess at what's safe */ -# define IOCPARM_LEN(x) 256 +# ifdef _IOC_SIZE + /* on Linux systems we're safe */ +# define IOCPARM_LEN(x) _IOC_SIZE(x) +# else + /* otherwise guess at what's safe (we're UNSAFE!) */ +# warning "unsafe assumption of IOCPARM_LEN=256" +# define IOCPARM_LEN(x) 256 +# endif # endif #endif This patch has been applied in the Red Hat perl-5.8.7-0.6.fc5 (Rawhide) release. Please consider applying the above patch, and fix this issue in future perl 5.8.8+ / 6.x releases. Thank You, Jason Vas Dias <jvdias@xxxxxxxxxx> Red Hat perl package maintainer [Please do not change anything below this line] ----------------------------------------------------------------- --- Flags: category=core severity=medium --- This perlbug was built using Perl v5.8.7 in the Red Hat build system. It is being executed now by Perl v5.8.7 - Tue Oct 25 17:23:30 EDT 2005. Site configuration information for perl v5.8.7: Configured by Red Hat, Inc. at Tue Oct 25 17:23:30 EDT 2005. Summary of my perl5 (revision 5 version 8 subversion 7) configuration: Platform: osname=linux, osvers=2.6.13-1.1624_fc5, archname=i386-linux-thread-multi uname='linux jvdias 2.6.13-1.1624_fc5 #1 mon oct 24 01:16:31 edt 2005 i686 i686 i386 gnulinux ' config_args='-des -Doptimize=-O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector --param=ssp-buffer-size=4 -m32 -march=i386 -mtune=pentium4 -fasynchronous-unwind-tables -Dversion=5.8.7 -Dmyhostname=localhost -Dperladmin=root@localhost -Dcc=gcc -Dcf_by=Red Hat, Inc. -Dinstallprefix=/usr -Dprefix=/usr -Darchname=i386-linux -Dvendorprefix=/usr -Dsiteprefix=/usr -Duseshrplib -Dusethreads -Duseithreads -Duselargefiles -Dd_dosuid -Dd_semctl_semun -Di_db -Ui_ndbm -Di_gdbm -Di_shadow -Di_syslog -Dman3ext=3pm -Duseperlio -Dinstallusrbinperl=n -Ubincompat5005 -Uversiononly -Dpager=/usr/bin/less -isr -Dd_gethostent_r_proto -Ud_endhostent_r_proto -Ud_sethostent_r_proto -Ud_endprotoent_r_proto -Ud_setprotoent_r_proto -Ud_endservent_r_proto -Ud_setservent_r_proto -Dinc_version_list=5.8.6 5.8.5 5.8.4 5.8.3 -Dscriptdir=/usr/bin' hint=recommended, useposix=true, d_sigaction=define usethreads=define use5005threads=undef useithreads=define usemultiplicity=define useperlio=define d_sfio=undef uselargefiles=define usesocks=undef use64bitint=undef use64bitall=undef uselongdouble=undef usemymalloc=n, bincompat5005=undef Compiler: cc='gcc', ccflags ='-D_REENTRANT -D_GNU_SOURCE -fno-strict-aliasing -pipe -I/usr/local/include -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 -I/usr/include/gdbm', optimize='-O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector --param=ssp-buffer-size=4 -m32 -march=i386 -mtune=pentium4 -fasynchronous-unwind-tables', cppflags='-D_REENTRANT -D_GNU_SOURCE -fno-strict-aliasing -pipe -I/usr/local/include -I/usr/include/gdbm' ccversion='', gccversion='4.0.2 20051007 (Red Hat 4.0.2-3)', gccosandvers='' intsize=4, longsize=4, ptrsize=4, doublesize=8, byteorder=1234 d_longlong=define, longlongsize=8, d_longdbl=define, longdblsize=12 ivtype='long', ivsize=4, nvtype='double', nvsize=8, Off_t='off_t', lseeksize=8 alignbytes=4, prototype=define Linker and Libraries: ld='gcc', ldflags =' -L/usr/local/lib' libpth=/usr/local/lib /lib /usr/lib libs=-lresolv -lnsl -lgdbm -ldb -ldl -lm -lcrypt -lutil -lpthread -lc perllibs=-lresolv -lnsl -ldl -lm -lcrypt -lutil -lpthread -lc libc=/lib/libc-2.3.90.so, so=so, useshrplib=true, libperl=libperl.so gnulibc_version='2.3.90' Dynamic Linking: dlsrc=dl_dlopen.xs, dlext=so, d_dlsymun=undef, ccdlflags='-Wl,-E -Wl,-rpath,/usr/lib/perl5/5.8.7/i386-linux-thread-multi/CORE' cccdlflags='-fPIC', lddlflags='-shared -L/usr/local/lib' Locally applied patches: --- @INC for perl v5.8.7: /usr/lib/perl5/site_perl/5.8.7/i386-linux-thread-multi /usr/lib/perl5/site_perl/5.8.6/i386-linux-thread-multi /usr/lib/perl5/site_perl/5.8.5/i386-linux-thread-multi /usr/lib/perl5/site_perl/5.8.4/i386-linux-thread-multi /usr/lib/perl5/site_perl/5.8.3/i386-linux-thread-multi /usr/lib/perl5/site_perl/5.8.7 /usr/lib/perl5/site_perl/5.8.6 /usr/lib/perl5/site_perl/5.8.5 /usr/lib/perl5/site_perl/5.8.4 /usr/lib/perl5/site_perl/5.8.3 /usr/lib/perl5/site_perl /usr/lib/perl5/vendor_perl/5.8.7/i386-linux-thread-multi /usr/lib/perl5/vendor_perl/5.8.6/i386-linux-thread-multi /usr/lib/perl5/vendor_perl/5.8.5/i386-linux-thread-multi /usr/lib/perl5/vendor_perl/5.8.4/i386-linux-thread-multi /usr/lib/perl5/vendor_perl/5.8.3/i386-linux-thread-multi /usr/lib/perl5/vendor_perl/5.8.7 /usr/lib/perl5/vendor_perl/5.8.6 /usr/lib/perl5/vendor_perl/5.8.5 /usr/lib/perl5/vendor_perl/5.8.4 /usr/lib/perl5/vendor_perl/5.8.3 /usr/lib/perl5/vendor_perl /usr/lib/perl5/5.8.7/i386-linux-thread-multi /usr/lib/perl5/5.8.7 . --- Environment for perl v5.8.7: HOME=/root LANG=en_US.UTF-8 LANGUAGE (unset) LD_LIBRARY_PATH (unset) LOGDIR (unset) PATH=/usr/kerberos/sbin:/usr/kerberos/bin:/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/usr/X11R6/bin:/root/bin PERL_BADLANG (unset) SHELL=/bin/bash