When building binaries using -O1 (or higher) and the -fzero-call-used-regs=all the resultant object files may create a broken binary when linked to. Reproducible: Always Steps to Reproduce: 1. Create a file named get_progname.c 2. Paste the following into get_progname.c: #include <string.h> #include <stdio.h> #include <stdlib.h> char *ssh_get_progname(char *argv0) { char *p, *q; extern char *__progname; p = __progname; if ((q = strdup(p)) == NULL) { perror("strdup"); exit(1); } return q; } 3. Execute clang -O1 -ggdb -fzero-call-used-regs=all -c get_progname.c 4. Create a file named test.c 5. Paste the following into test.c: #include <stdio.h> #include <stdlib.h> #include <string.h> #include <syslog.h> extern char *__progname; char *ssh_get_progname(char *); int main(int argc, char **argv) { __progname = ssh_get_progname(argv[0]); openlog(argv[0], 1, LOG_USER); return 0; } 6. Execute clang -O1 -ggdb -fzero-call-used-regs=all -c test.c 7. Execute clang -o test test.o get_progname.o 8. run ./test Actual Results: ./test segfaults due to argv[0] being incorrectly set to NULL during execution Expected Results: ./test should run and exit successfully. Portage 3.0.35 (python 3.10.7-final-0, default/linux/amd64/17.1/desktop, gcc-12.2.0, glibc-2.35-r8, 5.18.14-gentoo x86_64) ================================================================= System uname: Linux-5.18.14-gentoo-x86_64-Intel-R-_Core-TM-_i7-4771_CPU_@_3.50GHz-with-glibc2.35 KiB Mem: 32557860 total, 7752032 free KiB Swap: 2097148 total, 2045904 free Timestamp of repository gentoo: Mon, 12 Sep 2022 06:57:44 +0000 Head commit of repository gentoo: 3661d51653661eea567088e6e80385d8a14432c4 Timestamp of repository brother-overlay: Sun, 04 Sep 2022 19:46:50 +0000 Head commit of repository brother-overlay: 2c208f0df5aa5f9f967c361f0e3ad514e50422d0 Head commit of repository magpie: 10f020019b514442260050d216608c67910099cb sh bash 5.1_p16-r2 ld GNU ld (Gentoo 2.39 p4) 2.39.0 app-misc/pax-utils: 1.3.5::gentoo app-shells/bash: 5.1_p16-r2::gentoo dev-java/java-config: 2.3.1::gentoo dev-lang/perl: 5.36.0::gentoo dev-lang/python: 3.10.7::gentoo, 3.11.0_rc1_p2::gentoo dev-lang/rust: 1.63.0::magpie dev-util/cmake: 3.24.1::gentoo dev-util/meson: 0.63.2::gentoo sys-apps/baselayout: 2.8-r2::gentoo sys-apps/openrc: 0.45.2::gentoo sys-apps/sandbox: 2.29::gentoo sys-devel/autoconf: 2.13-r2::gentoo, 2.71-r2::gentoo sys-devel/automake: 1.16.5::gentoo sys-devel/binutils: 2.39-r2::gentoo sys-devel/binutils-config: 5.4.1::gentoo sys-devel/clang: 14.0.6-r1::gentoo, 15.0.0::gentoo sys-devel/gcc: 12.2.0::gentoo sys-devel/gcc-config: 2.5-r1::gentoo sys-devel/libtool: 2.4.7::gentoo sys-devel/lld: 15.0.0::gentoo sys-devel/llvm: 14.0.6-r2::gentoo, 15.0.0::gentoo sys-devel/make: 4.3::gentoo sys-kernel/linux-headers: 5.19::gentoo (virtual/os-headers) sys-libs/glibc: 2.35-r8::gentoo Repositories: gentoo location: /var/db/repos/gentoo sync-type: git sync-uri: https://github.com/gentoo-mirror/gentoo.git priority: -1000 sync-git-verify-commit-signature: true brother-overlay location: /var/db/repos/brother-overlay sync-type: git sync-uri: https://github.com/gentoo-mirror/brother-overlay.git masters: gentoo magpie location: /var/db/repos/magpie sync-type: git sync-uri: https://github.com/nvinson/magpie.git masters: gentoo ACCEPT_KEYWORDS="amd64 ~amd64" ACCEPT_LICENSE="* -@EULA" AR="llvm-ar" CBUILD="x86_64-pc-linux-gnu" CC="clang" CFLAGS="-march=native -O2 -pipe -D_FORTIFY_SOURCE=3 -fstack-protector-strong -flto=thin" CHOST="x86_64-pc-linux-gnu" CONFIG_PROTECT="/etc /opt/brother/scanner/brscan4/brsanenetdevice4.cfg /usr/lib64/libreoffice/program/sofficerc /usr/share/gnupg/qualified.txt" CONFIG_PROTECT_MASK="/etc/ca-certificates.conf /etc/dconf /etc/env.d /etc/fonts/fonts.conf /etc/gconf /etc/gentoo-release /etc/revdep-rebuild /etc/sandbox.d /etc/terminfo /etc/texmf/language.dat.d /etc/texmf/language.def.d /etc/texmf/updmap.d /etc/texmf/web2c" CXX="clang++" CXXFLAGS="-march=native -O2 -pipe -D_FORTIFY_SOURCE=3 -fstack-protector-strong -flto=thin" DISTDIR="/var/cache/portage/distfiles" EMERGE_DEFAULT_OPTS="--quiet-build" ENV_UNSET="CARGO_HOME DBUS_SESSION_BUS_ADDRESS DISPLAY GOBIN GOPATH PERL5LIB PERL5OPT PERLPREFIX PERL_CORE PERL_MB_OPT PERL_MM_OPT XAUTHORITY XDG_CACHE_HOME XDG_CONFIG_HO ME XDG_DATA_HOME XDG_RUNTIME_DIR" FCFLAGS="-march=native -O2 -pipe" FEATURES="assume-digests binpkg-docompress binpkg-dostrip binpkg-logs binpkg-multi-instance buildpkg-live config-protect-if-modified distlocks ebuild-locks fixlafiles ipc -sandbox merge-sync multilib-strict network-sandbox news parallel-fetch pid-sandbox preserve-libs protect-owned qa-unresolved-soname-deps sandbox sfperms strict unknown-f eatures-warn unmerge-logs unmerge-orphans userfetch userpriv usersandbox usersync xattr" FFLAGS="-march=native -O2 -pipe" GENTOO_MIRRORS="http://distfiles.gentoo.org" LANG="en_US.utf8" LDFLAGS="-Wl,-O1 -Wl,--as-needed -fuse-ld=lld -rtlib=compiler-rt -unwindlib=libunwind" MAKEOPTS="-j8" NM="llvm-nm" PKGDIR="/var/cache/binpkgs" PORTAGE_CONFIGROOT="/" PORTAGE_RSYNC_OPTS="--recursive --links --safe-links --perms --times --omit-dir-times --compress --force --whole-file --delete --stats --human-readable --timeout=180 --ex clude=/distfiles --exclude=/local --exclude=/packages --exclude=/.git" PORTAGE_TMPDIR="/var/tmp" RANLIB="llvm-ranlib" SHELL="/bin/zsh" USE="X a52 aac acl acpi alsa amd64 branding bzip2 cairo cdda cdr clang cleartype cli corefonts crypt cups dbus dri dts dvd dvdr elogind encode exif flac fortran gdbm gif glamor gpm gtk gui iconv icu ipv6 jpeg lcms libglvnd libnotify libtirpc mad mng mp3 mp4 mpeg multilib ncurses nls nptl ogg opengl openmp pam pango pcre pdf png policykit ppds qt5 readline sdl seccomp spell split-usr ssl startup-notification svg theora tiff truetype udev udisks unicode upower usb vaapi vorbis vpx wxwidgets x264 xattr xcb x ml xv xvid zlib" ABI_X86="64" ADA_TARGET="gnat_2020" 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 usertr ack vhost_alias" CALLIGRA_FEATURES="karbon sheets words" COLLECTD_PLUGINS="df interface irq load memory rrdtool swap syslog" CPU_FLAGS_X86="aes avx avx2 fma3 mmx mmxext p opcnt sse sse2 sse3 sse4 sse4_1 sse4_2 ssse3" ELIBC="glibc" GPSD_PROTOCOLS="ashtech aivdm earthmate evermore fv18 garmin garmintxt gpsclock greis isync itrax mtk3301 nmea ntrip navcom oceanserver oldstyle oncore rtcm104v2 rtcm104v3 sirf skytraq superstar2 timing tsip tripmate tnt ublox ubx" INPUT_DEVICES="libinput" KERNEL="linux" L10N="en -US en" LCD_DEVICES="bayrad cfontz cfontz633 glk hd44780 lb216 lcdm001 mtxorb ncurses text" LIBREOFFICE_EXTENSIONS="presenter-console presenter-minimizer" LUA_SINGLE_TARG ET="lua5-1" LUA_TARGETS="lua5-1" OFFICE_IMPLEMENTATION="libreoffice" PHP_TARGETS="php7-4 php8-0" POSTGRES_TARGETS="postgres12 postgres13" PYTHON_SINGLE_TARGET="python3_10 " PYTHON_TARGETS="python3_10" RUBY_TARGETS="ruby27" USERLAND="GNU" VIDEO_CARDS="intel i965" XTABLES_ADDONS="quota2 psd pknock lscan length2 ipv4options ipset ipp2p iface geoip fuzzy condition tee tarpit sysrq proto steal rawnat logmark ipmark dhcpmac delude chaos account" Unset: ADDR2LINE, ARFLAGS, AS, ASFLAGS, CCLD, CONFIG_SHELL, CPP, CPPFLAGS, CTARGET, CXXFILT, ELFEDIT, EXTRA_ECONF, F77FLAGS, FC, GCOV, GPROF, INSTALL_MASK, LC_ALL, LD, L EX, LFLAGS, LIBTOOL, LINGUAS, MAKE, MAKEFLAGS, OBJCOPY, OBJDUMP, PORTAGE_BINHOST, PORTAGE_BUNZIP2_COMMAND, PORTAGE_COMPRESS, PORTAGE_COMPRESS_FLAGS, PORTAGE_RSYNC_EXTRA_O PTS, READELF, RUSTFLAGS, SIZE, STRINGS, STRIP, YACC, YFLAGS
This was found when building openssh with clang-15. After building openssh, utilities such as ssh-keygen started segfaulting as described above.
FYI: __progname is initialized by glibc during program startup. It is a GNU extension.
(In reply to nvinson234 from comment #1) > This was found when building openssh with clang-15. After building openssh, > utilities such as ssh-keygen started segfaulting as described above. For completeness, I was building net-misc/openssh-9.0_p1-r3
I can confirm this (and was about to file a bug myself, although I didn't find the time to identify the root cause, i.e. compile flag, so kudos to you!) Another package that seems to be miscompiled with clang-15 is zsh, which simply hangs forever when executed afterwards. For the record, my system is fully built with libc++, but simply setting "CC=clang-14" and "CXX=clang-14" and rebuilding fixes both packages for me, even though they're being built against libc++-15. I am building with -O3 and besides that, no special CFLAGS.
(In reply to Manuel Nickschas from comment #4) > I can confirm this (and was about to file a bug myself, although I didn't > find the time to identify the root cause, i.e. compile flag, so kudos to > you!) > > Another package that seems to be miscompiled with clang-15 is zsh, which > simply hangs forever when executed afterwards. > > For the record, my system is fully built with libc++, but simply setting > "CC=clang-14" and "CXX=clang-14" and rebuilding fixes both packages for me, > even though they're being built against libc++-15. I am building with -O3 > and besides that, no special CFLAGS. That'll be bug 869539. We're going to have a lot of these, there's configure tests misfiring: https://discourse.llvm.org/t/configure-script-breakage-with-the-new-werror-implicit-function-declaration/65213.
(please report them all, I'm trying to find them, but it's not easy)
*** Bug 869911 has been marked as a duplicate of this bug. ***
The bug has been referenced in the following commit(s): https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=0a8dffa398fcbd459916ca331da9cb713372616a commit 0a8dffa398fcbd459916ca331da9cb713372616a Author: Sam James <sam@gentoo.org> AuthorDate: 2022-09-12 20:28:33 +0000 Commit: Sam James <sam@gentoo.org> CommitDate: 2022-09-12 20:28:33 +0000 net-misc/openssh: work around Clang 15 miscompilation with -fzero-call-used-regs=all Bug: https://github.com/llvm/llvm-project/issues/57692 Bug: https://bugs.gentoo.org/869839 Signed-off-by: Sam James <sam@gentoo.org> .../openssh/{openssh-9.0_p1-r3.ebuild => openssh-9.0_p1-r4.ebuild} | 4 ++++ 1 file changed, 4 insertions(+)
CCing Daniel as he seems to have reported this upstream to OpenSSH as well. Interestingly, this bug seems to persist in some cases even with 15.0.6! See https://github.com/llvm/llvm-project/issues/59242.
This is fixed upstream in https://github.com/llvm/llvm-project/commit/14d4cddc5506fb0fd3c4ac556b4edd970aa151eb. We've backported the fix in sys-devel/llvm-15.0.6-r1: ``` commit 691ee18503cb07d574461d81918ea02d4cb1f884 Author: Michał Górny <mgorny@gentoo.org> Date: Fri Jan 6 18:26:51 2023 +0100 sys-devel/llvm: Backport X86 CodeGen fix to 15.0.6-r1 Signed-off-by: Michał Górny <mgorny@gentoo.org> ``` It will also hopefully be included in 15.0.7 upstream.
