When clang is used to compile powertop, -O0 seems to result into a functioning application. Specifying -O1 or above results in an extremely long backtrace. Program received signal SIGSEGV, Segmentation fault. strncpy (__dest=0x7fffffffd3d0 "", __src=0x7ffff7fda718 "/proc/net/psched", __len=4095) at /usr/include/bits/string3.h:120 120 return __builtin___strncpy_chk (__dest, __src, __len, __bos (__dest)); (gdb) bt #0 strncpy (__dest=0x7fffffffd3d0 "", __src=0x7ffff7fda718 "/proc/net/psched", __len=4095) at /usr/include/bits/string3.h:120 #1 0x0000000000410ae9 in strncpy (__dest=0x7fffffffd3d0 "", __src=0x7ffff7fda718 "/proc/net/psched", __len=4095) at /usr/include/bits/string3.h:120 #2 0x0000000000410ae9 in strncpy (__dest=0x7fffffffd3d0 "", __src=0x7ffff7fda718 "/proc/net/psched", __len=4095) at /usr/include/bits/string3.h:120 (repeating) A quick fix wound be to set the optimisation to -O0. Portage 2.2.7 (default/linux/amd64/13.0/no-multilib, gcc-4.8.2, glibc-2.17, 3.12.5-gentoo x86_64) ================================================================= System uname: Linux-3.12.5-gentoo-x86_64-Intel-R-_Xeon-R-_CPU_X5450_@_3.00GHz-with-gentoo-2.2 KiB Mem: 32950768 total, 32538036 free KiB Swap: 4194300 total, 4194300 free Timestamp of tree: Tue, 17 Dec 2013 22:00:01 +0000 ld GNU gold (GNU Binutils 2.23.2) 1.11 app-shells/bash: 4.2_p45 dev-lang/python: 2.7.6, 3.3.3 dev-util/pkgconfig: 0.28 sys-apps/baselayout: 2.2 sys-apps/openrc: 0.12.4 sys-apps/sandbox: 2.6-r1 sys-devel/autoconf: 2.69 sys-devel/automake: 1.12.6, 1.13.4, 1.14 sys-devel/binutils: 2.23.2 sys-devel/gcc: 4.7.3-r1, 4.8.2 sys-devel/gcc-config: 1.8 sys-devel/libtool: 2.4.2 sys-devel/make: 4.0-r1 sys-kernel/linux-headers: 3.12 (virtual/os-headers) sys-libs/glibc: 2.17 Repositories: gentoo ACCEPT_KEYWORDS="amd64 ~amd64" ACCEPT_LICENSE="*" CBUILD="x86_64-pc-linux-gnu" CFLAGS="-O2 -pipe -O2 -march=native -pipe" CHOST="x86_64-pc-linux-gnu" CONFIG_PROTECT="/etc /usr/share/gnupg/qualified.txt" CONFIG_PROTECT_MASK="/etc/ca-certificates.conf /etc/env.d /etc/gconf /etc/gentoo-release /etc/sandbox.d /etc/terminfo" CXXFLAGS="-O2 -pipe -O2 -march=native -pipe" DISTDIR="/var/tmp/distfiles" FCFLAGS="-O2 -pipe" FEATURES="assume-digests binpkg-logs config-protect-if-modified distlocks ebuild-locks fixlafiles merge-sync news parallel-fetch preserve-libs protect-owned sandbox sfperms strict unknown-features-warn unmerge-logs unmerge-orphans userfetch userpriv usersandbox usersync" FFLAGS="-O2 -pipe" GENTOO_MIRRORS="http://distfiles.gentoo.org" LANG="en_US.UTF-8" LC_ALL="en_US.UTF-8" LDFLAGS="-Wl,-O1 -Wl,--as-needed" MAKEOPTS="-j9" PKGDIR="/var/tmp/packages" PORTAGE_CONFIGROOT="/" PORTAGE_RSYNC_OPTS="--recursive --links --safe-links --perms --times --omit-dir-times --compress --force --whole-file --delete --stats --human-readable --timeout=180 --exclude=/distfiles --exclude=/local --exclude=/packages" PORTAGE_TMPDIR="/var/tmp" PORTDIR="/usr/portage" PORTDIR_OVERLAY="" USE="amd64 berkdb bzip2 caps cli cracklib crypt cxx dri fortran gdbm iconv ipv6 lto mmx modules ncurses openmp pcre python2 readline session sse sse2 ssl tcpd threads unicode vim-syntax zlib" ABI_X86="64" ALSA_CARDS="ali5451 als4000 atiixp atiixp-modem bt87x ca0106 cmipci emu10k1x ens1370 ens1371 es1938 es1968 fm801 hda-intel intel8x0 intel8x0m maestro3 trident usb-audio via82xx via82xx-modem ymfpci" APACHE2_MODULES="authn_core authz_core socache_shmcb unixd actions alias auth_basic authn_alias authn_anon authn_dbm authn_default authn_file authz_dbm authz_default authz_groupfile authz_host authz_owner authz_user autoindex cache cgi cgid dav dav_fs dav_lock deflate dir disk_cache env expires ext_filter file_cache filter headers include info log_config logio mem_cache mime mime_magic negotiation rewrite setenvif speling status unique_id userdir usertrack vhost_alias" CALLIGRA_FEATURES="kexi words flow plan sheets stage tables krita karbon braindump author" CAMERAS="ptp2" COLLECTD_PLUGINS="df interface irq load memory rrdtool swap syslog" ELIBC="glibc" GPSD_PROTOCOLS="ashtech aivdm earthmate evermore fv18 garmin garmintxt gpsclock itrax mtk3301 nmea ntrip navcom oceanserver oldstyle oncore rtcm104v2 rtcm104v3 sirf superstar2 timing tsip tripmate tnt ublox ubx" INPUT_DEVICES="keyboard mouse evdev" KERNEL="linux" LCD_DEVICES="bayrad cfontz cfontz633 glk hd44780 lb216 lcdm001 mtxorb ncurses text" LIBREOFFICE_EXTENSIONS="presenter-console presenter-minimizer" OFFICE_IMPLEMENTATION="libreoffice" PHP_TARGETS="php5-5" PYTHON_SINGLE_TARGET="python2_7" PYTHON_TARGETS="python2_7" RUBY_TARGETS="ruby19 ruby18" USERLAND="GNU" VIDEO_CARDS="fbdev glint intel mach64 mga nouveau nv r128 radeon savage sis tdfx trident vesa via vmware dummy v4l" XTABLES_ADDONS="quota2 psd pknock lscan length2 ipv4options ipset ipp2p iface geoip fuzzy condition tee tarpit sysrq steal rawnat logmark ipmark dhcpmac delude chaos account" Unset: CPPFLAGS, CTARGET, EMERGE_DEFAULT_OPTS, INSTALL_MASK, PORTAGE_BUNZIP2_COMMAND, PORTAGE_COMPRESS, PORTAGE_COMPRESS_FLAGS, PORTAGE_RSYNC_EXTRA_OPTS, SYNC, USE_PYTHON
Shouldn't this be reported to upstream? We basically don't patch powertop at all so I'm sure this isn't a gentoo bug.