dhp@mercure:/tmp$ cat main.c int main() { return(0); } dhp@mercure:/tmp$ gcc main.c -Wall dhp@mercure:/tmp$ valgrind --tool=memcheck --db-attach=yes ./a.out ==21536== Memcheck, a memory error detector for x86-linux. ==21536== Copyright (C) 2002-2005, and GNU GPL'd, by Julian Seward et al. ==21536== Using valgrind-2.4.0, a program supervision framework for x86-linux. ==21536== Copyright (C) 2000-2005, and GNU GPL'd, by Julian Seward et al. ==21536== For more details, rerun with: -v ==21536== ==21536== Conditional jump or move depends on uninitialised value(s) ==21536== at 0x1B8EE260: (within /lib/ld-2.3.5.so) ==21536== by 0x1B8E6A01: (within /lib/ld-2.3.5.so) ==21536== by 0x1B8F4F37: (within /lib/ld-2.3.5.so) ==21536== ==21536== ---- Attach to debugger ? --- [Return/N/n/Y/y/C/c] ---- ==21536== ==21536== Conditional jump or move depends on uninitialised value(s) ==21536== at 0x1B8EE290: (within /lib/ld-2.3.5.so) ==21536== by 0x1B8E6A01: (within /lib/ld-2.3.5.so) ==21536== by 0x1B8F4F37: (within /lib/ld-2.3.5.so) ==21536== ==21536== ---- Attach to debugger ? --- [Return/N/n/Y/y/C/c] ---- ==21536== ==21536== Conditional jump or move depends on uninitialised value(s) ==21536== at 0x1B8EE114: (within /lib/ld-2.3.5.so) ==21536== by 0x1B8E6A01: (within /lib/ld-2.3.5.so) ==21536== by 0x1B8F4F37: (within /lib/ld-2.3.5.so) <SNIP> : in fact there are always 7 such sections root@mercure:~# equery b /lib/ld-2.3.5.so [ Searching for file(s) /lib/ld-2.3.5.so in *... ] sys-libs/glibc-2.3.5 (/lib/ld-2.3.5.so) root@mercure:~# emerge -vp sys-libs/glibc These are the packages that I would merge, in order: Calculating dependencies ...done! [ebuild R ] sys-libs/glibc-2.3.5 -build -debug -erandom -hardened (-multilib) +nls -nomalloccheck +nptl -nptlonly -pic -userlocales 0 kB Total size of downloads: 0 kB root@mercure:~# emerge info Portage 2.0.51.22-r1 (default-linux/x86/2005.0, gcc-3.4.4, glibc-2.3.5-r0, 2.6.11.10-vs2.0-rc2_mercure_03_vs i686) ================================================================= System uname: 2.6.11.10-vs2.0-rc2_mercure_03_vs i686 AMD Athlon(tm) 4 Processor Gentoo Base System version 1.6.12 distcc 2.18.3 i686-pc-linux-gnu (protocols 1 and 2) (default port 3632) [disabled] dev-lang/python: 2.3.5 sys-apps/sandbox: 1.2.8 sys-devel/autoconf: 2.13, 2.59-r6 sys-devel/automake: 1.4_p6, 1.5, 1.6.3, 1.7.9-r1, 1.8.5-r3, 1.9.5 sys-devel/binutils: 2.16-r1 sys-devel/libtool: 1.5.18 virtual/os-headers: 2.6.11-r1 ACCEPT_KEYWORDS="x86 ~x86" AUTOCLEAN="yes" CBUILD="i686-pc-linux-gnu" CFLAGS="-O2 -march=pentium3 -fomit-frame-pointer -pipe" CHOST="i686-pc-linux-gnu" CONFIG_PROTECT="/etc /usr/kde/2/share/config /usr/kde/3.4/env /usr/kde/3.4/share/config /usr/kde/3.4/shutdown /usr/kde/3/share/config /usr/lib/X11/xkb /usr/share/config /var/qmail/control" CONFIG_PROTECT_MASK="/etc/gconf /etc/terminfo /etc/texmf/web2c /etc/env.d" CXXFLAGS="-O2 -march=pentium3 -fomit-frame-pointer -pipe" DISTDIR="/usr/portage/distfiles" FEATURES="autoconfig distlocks sandbox sfperms strict" GENTOO_MIRRORS="http://distfiles.gentoo.org http://distro.ibiblio.org/pub/Linux/distributions/gentoo" LANG="en_GB" LC_ALL="en_GB" MAKEOPTS="-j2" PKGDIR="/usr/portage/packages" PORTAGE_TMPDIR="/var/tmp" PORTDIR="/usr/portage" SYNC="rsync://rsync.gentoo.org/gentoo-portage" USE="x86 3dnowex X a52 aac aalib alsa apache2 apm arts avi bash-completion berkdb bitmap-fonts bzlib cairo caps cdr cle266 cmov crypt cups curl cx8 dba de directfb divx4linux djbfft doc dpms dts dv dvb dvd dvdread elf emacs emboss encode escreen esd ethereal fbcon ffmpeg fftw flac font-server foomaticdb fortran fpu fpx ftp fxsr gd gdbm gif gnutls gpm graphviz gstreamer gtk gtk2 hdf5 imagemagick imlib ipv6 java javascript jbig jpeg kerberos krb4 lcms ldap libcaca libclamav libg++ libwww lirc live lzo mad matroska matrox mbox mca mce mikmod mmap mmx mng motif mp3 mpeg mpi msr mtrr mysql mythtv ncurses network nls nptl objc odbc ogg oggvorbis opengl oss pae pam pam_chroot pam_console pam_timestamp pat pcre pdflib perl pge plotutils png pnp posix postgres pse pse36 pwdb python qt quicktime readline real rrdtool rtc ruby samba sasl sdl sendfile sep serial skey slang sndfile snmp speex spell sse ssl streamzap svga sysfs syslog sysvipc tcpd tetex tga theora threads tiff truetype truetype-fonts tsc type1-fonts unicode v4l v4l2 vcd vidix vim vme vorbis win32codecs wmf xanim xine xinerama xml xml2 xmlrpc xmms xpm xv xvid xvmc zlib userland_GNU kernel_linux elibc_glibc" Unset: ASFLAGS, CTARGET, LDFLAGS, LINGUAS, PORTDIR_OVERLAY I very heavily use valgrind everyday, and those warnings REALY feed me up. -1- can you feedback upstream about that ? -2- is there a workaround to ask valgrind NOT show warnings for the particular library ld.so ? -3- is there a workaround ?
> -1- can you feedback upstream about that ? Upstream probably knows about those already. See below. > -2- is there a workaround to ask valgrind NOT show warnings for the particular library ld.so ? Yes, that's possible. Look into suppression files: http://valgrind.org/docs/manual/coregrind_core.html#suppress > -3- is there a workaround ? Here are 2 of them: 1) Do not strip glibc. Valgrind comes with several default suppression files for glibc likely to mask the issues you see. The only problem is that those suppression files need function names in backtraces in order to suppress something properly. Stripping debugging info from glibc gives you backtraces without function names. 2) Create your own suppression file and use that with valgrind. The documentation tells you how to do this. You may however be masking other problems if you go for a suppression as general as "anything in ld-2.3.5.so".
I'll mark this report INVALID, since stripping glibc obviously makes it impossible for valgrind to suppress the right messages. If you disagree, please let me know.
yes I desagree because the errors reported are about from memory: jump deponds on uninitialised variable. this means the glib can have unpredictable behaviour ... and valgrind shows up a potential bug due to bad-coding. valgrind only reveal 'problems' ... if code were clean, it would not complain. I think you should mail upstream. maybe those warnings are non fatal to me ... maybe they ll make crash other applications soon.
