thr3ads.net - openssh unix dev - vanilla build of 7.7p1 release on linux/4.17 fails with gcc8 @ "/usr/bin/ld: unrecognized option '-Wl,-z,retpolineplt'" [Jun 2018]

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PGNet Dev

2018-Jun-07 21:09 UTC

vanilla build of 7.7p1 release on linux/4.17 fails with gcc8 @ "/usr/bin/ld: unrecognized option '-Wl,-z,retpolineplt'"

Verifying a report I just got pinged about, building vanilla openssh 7.7p1 on
linux configures ok, but fails build around 'retpoline'

I've started looking through recent reports; haven't _yet_ found
anything similar.

While I continue, is any of the following familiar/expected?  Either known
bug/issue or env conflict?

The current env includes supposedly retpoline-ready GCC 8.1.1,

	uname -rm
		4.17.0-lp150.2.gbcb3422-default x86_64

	cat /sys/devices/system/cpu/vulnerabilities/spectre_v2
		Mitigation: Full AMD retpoline

	gcc-8 -v
		Using built-in specs.
		Reading specs from /usr/lib64/gcc/x86_64-suse-linux/8/defaults.spec
		COLLECT_GCC=gcc-8
		COLLECT_LTO_WRAPPER=/usr/lib64/gcc/x86_64-suse-linux/8/lto-wrapper
		OFFLOAD_TARGET_NAMES=hsa:nvptx-none
		Target: x86_64-suse-linux
		Configured with: ../configure --prefix=/usr --infodir=/usr/share/info
--mandir=/usr/share/man --libdir=/usr/lib64 --libexecdir=/usr/lib64
--enable-languages=c,c++,objc,fortran,obj-c++,ada,go
--enable-offload-targets=hsa,nvptx-none=/usr/nvptx-none, --without-cuda-driver
--enable-checking=release --disable-werror
--with-gxx-include-dir=/usr/include/c++/8 --enable-ssp --disable-libssp
--disable-libvtv --disable-cet --disable-libcc1 --enable-plugin
--with-bugurl=http://bugs.opensuse.org/ --with-pkgversion='SUSE Linux'
--with-slibdir=/lib64 --with-system-zlib --enable-__cxa_atexit
--enable-libstdcxx-allocator=new --disable-libstdcxx-pch
--enable-version-specific-runtime-libs --with-gcc-major-version-only
--enable-linker-build-id --enable-linux-futex --enable-gnu-indirect-function
--program-suffix=-8 --without-system-libunwind --enable-multilib
--with-arch-32=x86-64 --with-tune=generic --build=x86_64-suse-linux
--host=x86_64-suse-linux
		Thread model: posix
		gcc version 8.1.1 20180523 [gcc-8-branch revision 260570] (SUSE Linux)

	ld -v
		GNU ld (GNU Binutils; home:pgnd:devel:gcc8 / openSUSE_Leap_15.0)
2.30.0.20180320-lp150.319

removing all optimization presets

	unset CFLAGS LDFLAGS CPPFLAGS CXXFLAGS
	echo $CC $CPP $CXX $LD
		/usr/bin/gcc-8 /usr/bin/cpp-8 /usr/bin/g++-8 /usr/bin/ld

configuring

	cd openssh-7.7p1
	./configure --without-openssl
		...
		configure: creating ./config.status
		config.status: creating Makefile
		config.status: creating buildpkg.sh
		config.status: creating opensshd.init
		config.status: creating openssh.xml
		config.status: creating openbsd-compat/Makefile
		config.status: creating openbsd-compat/regress/Makefile
		config.status: creating survey.sh
		config.status: creating config.h
		config.status: config.h is unchanged
		OpenSSH has been configured with the following options:
		                     User binaries: /usr/local/bin
		                   System binaries: /usr/local/sbin
		               Configuration files: /usr/local/etc
		                   Askpass program: /usr/local/lib/ssh-askpass
		                      Manual pages: /usr/local/share/man/manX
		                          PID file: /var/run
		  Privilege separation chroot path: /var/empty
		            sshd default user PATH:
/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/bin
		                    Manpage format: doc
		                       PAM support: no
		                   OSF SIA support: no
		                 KerberosV support: no
		                   SELinux support: no
		                     S/KEY support: no
		              MD5 password support: no
		                   libedit support: no
		                   libldns support: no
		  Solaris process contract support: no
		           Solaris project support: no
		         Solaris privilege support: no
		       IP address in $DISPLAY hack: no
		           Translate v4 in v6 hack: yes
		                  BSD Auth support: no
		              Random number source:
		             Privsep sandbox style: seccomp_filter

		              Host: x86_64-pc-linux-gnu
		          Compiler: /usr/bin/gcc-8
		    Compiler flags: -g -O2 -pipe -Wall -Wpointer-arith -Wuninitialized
-Wsign-compare -Wformat-security -Wsizeof-pointer-memaccess -Wno-pointer-sign
-Wno-unused-result -fno-strict-aliasing -mfunction-return=thunk
-mindirect-branch=thunk -D_FORTIFY_SOURCE=2 -ftrapv -fno-builtin-memset
-fstack-protector-strong -fPIE
		Preprocessor flags:  -D_XOPEN_SOURCE=600 -D_BSD_SOURCE -D_DEFAULT_SOURCE
		      Linker flags:  -Wl,-z,retpolineplt -Wl,-z,relro -Wl,-z,now
-Wl,-z,noexecstack -fstack-protector-strong -pie
		         Libraries: -lutil -lz  -lcrypt -lresolv

reports no errors.

build,

	make V=1

		...
		a - platform-tracing.o
		a - platform-misc.o
		ranlib libssh.a
		/usr/bin/gcc-8 -g -O2 -pipe -Wall -Wpointer-arith -Wuninitialized
-Wsign-compare -Wformat-security -Wsizeof-pointer-memaccess -Wno-pointer-sign
-Wno-unused-result -fno-strict-aliasing -mfunction-return=thunk
-mindirect-branch=thunk -D_FORTIFY_SOURCE=2 -ftrapv -fno-builtin-memset
-fstack-protector-strong -fPIE   -I. -I.  -D_XOPEN_SOURCE=600 -D_BSD_SOURCE
-D_DEFAULT_SOURCE -DSSHDIR=\"/usr/local/etc\"
-D_PATH_SSH_PROGRAM=\"/usr/local/bin/ssh\"
-D_PATH_SSH_ASKPASS_DEFAULT=\"/usr/local/lib/ssh-askpass\"
-D_PATH_SFTP_SERVER=\"/usr/local/lib/sftp-server\"
-D_PATH_SSH_KEY_SIGN=\"/usr/local/lib/ssh-keysign\"
-D_PATH_SSH_PKCS11_HELPER=\"/usr/local/lib/ssh-pkcs11-helper\"
-D_PATH_SSH_PIDDIR=\"/var/run\"
-D_PATH_PRIVSEP_CHROOT_DIR=\"/var/empty\" -DHAVE_CONFIG_H -c ssh.c -o
ssh.o
		/usr/bin/gcc-8 -g -O2 -pipe -Wall -Wpointer-arith -Wuninitialized
-Wsign-compare -Wformat-security -Wsizeof-pointer-memaccess -Wno-pointer-sign
-Wno-unused-result -fno-strict-aliasing -mfunction-return=thunk
-mindirect-branch=thunk -D_FORTIFY_SOURCE=2 -ftrapv -fno-builtin-memset
-fstack-protector-strong -fPIE   -I. -I.  -D_XOPEN_SOURCE=600 -D_BSD_SOURCE
-D_DEFAULT_SOURCE -DSSHDIR=\"/usr/local/etc\"
-D_PATH_SSH_PROGRAM=\"/usr/local/bin/ssh\"
-D_PATH_SSH_ASKPASS_DEFAULT=\"/usr/local/lib/ssh-askpass\"
-D_PATH_SFTP_SERVER=\"/usr/local/lib/sftp-server\"
-D_PATH_SSH_KEY_SIGN=\"/usr/local/lib/ssh-keysign\"
-D_PATH_SSH_PKCS11_HELPER=\"/usr/local/lib/ssh-pkcs11-helper\"
-D_PATH_SSH_PIDDIR=\"/var/run\"
-D_PATH_PRIVSEP_CHROOT_DIR=\"/var/empty\" -DHAVE_CONFIG_H -c
readconf.c -o readconf.o
		/usr/bin/gcc-8 -g -O2 -pipe -Wall -Wpointer-arith -Wuninitialized
-Wsign-compare -Wformat-security -Wsizeof-pointer-memaccess -Wno-pointer-sign
-Wno-unused-result -fno-strict-aliasing -mfunction-return=thunk
-mindirect-branch=thunk -D_FORTIFY_SOURCE=2 -ftrapv -fno-builtin-memset
-fstack-protector-strong -fPIE   -I. -I.  -D_XOPEN_SOURCE=600 -D_BSD_SOURCE
-D_DEFAULT_SOURCE -DSSHDIR=\"/usr/local/etc\"
-D_PATH_SSH_PROGRAM=\"/usr/local/bin/ssh\"
-D_PATH_SSH_ASKPASS_DEFAULT=\"/usr/local/lib/ssh-askpass\"
-D_PATH_SFTP_SERVER=\"/usr/local/lib/sftp-server\"
-D_PATH_SSH_KEY_SIGN=\"/usr/local/lib/ssh-keysign\"
-D_PATH_SSH_PKCS11_HELPER=\"/usr/local/lib/ssh-pkcs11-helper\"
-D_PATH_SSH_PIDDIR=\"/var/run\"
-D_PATH_PRIVSEP_CHROOT_DIR=\"/var/empty\" -DHAVE_CONFIG_H -c
clientloop.c -o clientloop.o
		clientloop.c: In function ?client_x11_get_proto?:
		clientloop.c:378:14: warning: ?%s? directive output may be truncated writing
up to 4095 bytes into a region of size 1020 [-Wformat-truncation=]
		        "%s %s%s list %s 2>" _PATH_DEVNULL,
		              ^~
		clientloop.c:381:20:
		        generated ? xauthfile : "",
		                    ~~~~~~~~~
		In file included from /usr/include/stdio.h:862,
		                 from /usr/include/bsd/libutil.h:46,
		                 from includes.h:141,
		                 from clientloop.c:62:
		/usr/include/bits/stdio2.h:64:10: note: ?__builtin___snprintf_chk? output 23
or more bytes (assuming 4118) into a destination of size 1024
		   return __builtin___snprintf_chk (__s, __n, __USE_FORTIFY_LEVEL - 1,
		          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
		        __bos (__s), __fmt, __va_arg_pack ());
		        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
		/usr/bin/gcc-8 -g -O2 -pipe -Wall -Wpointer-arith -Wuninitialized
-Wsign-compare -Wformat-security -Wsizeof-pointer-memaccess -Wno-pointer-sign
-Wno-unused-result -fno-strict-aliasing -mfunction-return=thunk
-mindirect-branch=thunk -D_FORTIFY_SOURCE=2 -ftrapv -fno-builtin-memset
-fstack-protector-strong -fPIE   -I. -I.  -D_XOPEN_SOURCE=600 -D_BSD_SOURCE
-D_DEFAULT_SOURCE -DSSHDIR=\"/usr/local/etc\"
-D_PATH_SSH_PROGRAM=\"/usr/local/bin/ssh\"
-D_PATH_SSH_ASKPASS_DEFAULT=\"/usr/local/lib/ssh-askpass\"
-D_PATH_SFTP_SERVER=\"/usr/local/lib/sftp-server\"
-D_PATH_SSH_KEY_SIGN=\"/usr/local/lib/ssh-keysign\"
-D_PATH_SSH_PKCS11_HELPER=\"/usr/local/lib/ssh-pkcs11-helper\"
-D_PATH_SSH_PIDDIR=\"/var/run\"
-D_PATH_PRIVSEP_CHROOT_DIR=\"/var/empty\" -DHAVE_CONFIG_H -c sshtty.c
-o sshtty.o
		/usr/bin/gcc-8 -g -O2 -pipe -Wall -Wpointer-arith -Wuninitialized
-Wsign-compare -Wformat-security -Wsizeof-pointer-memaccess -Wno-pointer-sign
-Wno-unused-result -fno-strict-aliasing -mfunction-return=thunk
-mindirect-branch=thunk -D_FORTIFY_SOURCE=2 -ftrapv -fno-builtin-memset
-fstack-protector-strong -fPIE   -I. -I.  -D_XOPEN_SOURCE=600 -D_BSD_SOURCE
-D_DEFAULT_SOURCE -DSSHDIR=\"/usr/local/etc\"
-D_PATH_SSH_PROGRAM=\"/usr/local/bin/ssh\"
-D_PATH_SSH_ASKPASS_DEFAULT=\"/usr/local/lib/ssh-askpass\"
-D_PATH_SFTP_SERVER=\"/usr/local/lib/sftp-server\"
-D_PATH_SSH_KEY_SIGN=\"/usr/local/lib/ssh-keysign\"
-D_PATH_SSH_PKCS11_HELPER=\"/usr/local/lib/ssh-pkcs11-helper\"
-D_PATH_SSH_PIDDIR=\"/var/run\"
-D_PATH_PRIVSEP_CHROOT_DIR=\"/var/empty\" -DHAVE_CONFIG_H -c
sshconnect.c -o sshconnect.o
		sshconnect.c: In function ?check_host_key.constprop?:
		sshconnect.c:1047:8: warning: ?%s? directive output may be truncated writing
up to 1023 bytes into a region of size between 773 and 973
[-Wformat-truncation=]
		        "The authenticity of host '%.200s (%s)' can't be
"
		        ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
		sshconnect.c:1052:18:
		        host, ip, msg1, type, fp,
		                  ~~~~
		sshconnect.c:1048:20: note: format string is defined here
		        "established%s\n"
		                    ^~
		In file included from /usr/include/stdio.h:862,
		                 from /usr/include/bsd/libutil.h:46,
		                 from includes.h:141,
		                 from sshconnect.c:16:
		/usr/include/bits/stdio2.h:64:10: note: ?__builtin___snprintf_chk? output 130
or more bytes (assuming 2377) into a destination of size 1024
		   return __builtin___snprintf_chk (__s, __n, __USE_FORTIFY_LEVEL - 1,
		          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
		        __bos (__s), __fmt, __va_arg_pack ());
		        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
		/usr/bin/gcc-8 -g -O2 -pipe -Wall -Wpointer-arith -Wuninitialized
-Wsign-compare -Wformat-security -Wsizeof-pointer-memaccess -Wno-pointer-sign
-Wno-unused-result -fno-strict-aliasing -mfunction-return=thunk
-mindirect-branch=thunk -D_FORTIFY_SOURCE=2 -ftrapv -fno-builtin-memset
-fstack-protector-strong -fPIE   -I. -I.  -D_XOPEN_SOURCE=600 -D_BSD_SOURCE
-D_DEFAULT_SOURCE -DSSHDIR=\"/usr/local/etc\"
-D_PATH_SSH_PROGRAM=\"/usr/local/bin/ssh\"
-D_PATH_SSH_ASKPASS_DEFAULT=\"/usr/local/lib/ssh-askpass\"
-D_PATH_SFTP_SERVER=\"/usr/local/lib/sftp-server\"
-D_PATH_SSH_KEY_SIGN=\"/usr/local/lib/ssh-keysign\"
-D_PATH_SSH_PKCS11_HELPER=\"/usr/local/lib/ssh-pkcs11-helper\"
-D_PATH_SSH_PIDDIR=\"/var/run\"
-D_PATH_PRIVSEP_CHROOT_DIR=\"/var/empty\" -DHAVE_CONFIG_H -c
sshconnect2.c -o sshconnect2.o
		/usr/bin/gcc-8 -g -O2 -pipe -Wall -Wpointer-arith -Wuninitialized
-Wsign-compare -Wformat-security -Wsizeof-pointer-memaccess -Wno-pointer-sign
-Wno-unused-result -fno-strict-aliasing -mfunction-return=thunk
-mindirect-branch=thunk -D_FORTIFY_SOURCE=2 -ftrapv -fno-builtin-memset
-fstack-protector-strong -fPIE   -I. -I.  -D_XOPEN_SOURCE=600 -D_BSD_SOURCE
-D_DEFAULT_SOURCE -DSSHDIR=\"/usr/local/etc\"
-D_PATH_SSH_PROGRAM=\"/usr/local/bin/ssh\"
-D_PATH_SSH_ASKPASS_DEFAULT=\"/usr/local/lib/ssh-askpass\"
-D_PATH_SFTP_SERVER=\"/usr/local/lib/sftp-server\"
-D_PATH_SSH_KEY_SIGN=\"/usr/local/lib/ssh-keysign\"
-D_PATH_SSH_PKCS11_HELPER=\"/usr/local/lib/ssh-pkcs11-helper\"
-D_PATH_SSH_PIDDIR=\"/var/run\"
-D_PATH_PRIVSEP_CHROOT_DIR=\"/var/empty\" -DHAVE_CONFIG_H -c mux.c -o
mux.o
		/usr/bin/ld -o ssh ssh.o readconf.o clientloop.o sshtty.o sshconnect.o
sshconnect2.o mux.o -L. -Lopenbsd-compat/  -Wl,-z,retpolineplt -Wl,-z,relro
-Wl,-z,now -Wl,-z,noexecstack -fstack-protector-strong -pie  -lssh
-lopenbsd-compat  -lutil -lz  -lcrypt -lresolv
		/usr/bin/ld: unrecognized option '-Wl,-z,retpolineplt'
		/usr/bin/ld: use the --help option for usage information
		make: *** [Makefile:172: ssh] Error 1

The ldflags check originates in

	cat configure.ac
		...
164	    if test "x$use_toolchain_hardening" = "x1"; then
	    OSSH_CHECK_CFLAG_COMPILE([-mfunction-return=thunk]) # gcc
	    OSSH_CHECK_CFLAG_COMPILE([-mindirect-branch=thunk]) # gcc
	    OSSH_CHECK_CFLAG_COMPILE([-mretpoline]) # clang
!!	    OSSH_CHECK_LDFLAG_LINK([-Wl,-z,retpolineplt])
	    OSSH_CHECK_CFLAG_COMPILE([-D_FORTIFY_SOURCE=2])
	    OSSH_CHECK_LDFLAG_LINK([-Wl,-z,relro])
		...

I've not had any issues, yet, with any other of many packages I build with
this GCC env; this fail is, so far, unique to this openssh build attempt.

Not clear yet if relevant, noting @ HardenedBSD,

	"HBSD: Do not enable RETPOLINE if LLD_UNSAFE or USE_GCC is set"
	
https://github.com/HardenedBSD/hardenedbsd-ports/commit/e57638c87f44c91c12539bb9fc5d00b862a4974a

Should the retpoline flag be getting added?  If so, what's needed to make LD
happy with it?

Darren Tucker

2018-Jun-07 23:03 UTC

head link

vanilla build of 7.7p1 release on linux/4.17 fails with gcc8 @ "/usr/bin/ld: unrecognized option '-Wl,-z,retpolineplt'"

On 8 June 2018 at 07:09, PGNet Dev <pgnet.dev at gmail.com>
wrote:> Verifying a report I just got pinged about, building vanilla openssh 7.7p1
on linux configures ok, but fails build around 'retpoline'
[...]> Should the retpoline flag be getting added?  If so, what's needed to
make LD happy with it?
configure checks to see if the linker accepts those flags, so my guess
is that something is added later in configure that causes it to fail.
I suggest looking at config.log to see what the actaul compiler
messages are from these parts:

OSSH_CHECK_CFLAG_COMPILE([-mretpoline]) # clang
OSSH_CHECK_LDFLAG_LINK([-Wl,-z,retpolineplt])

and the actual compiler output show up in config.log.

I wrote and tested this patch against the development versions of gcc
and clang which was all that was available at the time, it's possible
the released versions don't behave quite the same.

-- 
Darren Tucker (dtucker at dtucker.net)
GPG key 11EAA6FA / A86E 3E07 5B19 5880 E860  37F4 9357 ECEF 11EA A6FA (new)
    Good judgement comes with experience. Unfortunately, the experience
usually comes from bad judgement.

PGNet Dev

2018-Jun-07 23:44 UTC

head link

vanilla build of 7.7p1 release on linux/4.17 fails with gcc8 @ "/usr/bin/ld: unrecognized option '-Wl,-z,retpolineplt'"

hi

On 6/7/18 4:03 PM, Darren Tucker wrote:> On 8 June 2018 at 07:09, PGNet Dev <pgnet.dev at gmail.com> wrote:
>> Verifying a report I just got pinged about, building vanilla openssh
7.7p1 on linux configures ok, but fails build around 'retpoline'
> [...]
>> Should the retpoline flag be getting added?  If so, what's needed
to make LD happy with it?
> 
> configure checks to see if the linker accepts those flags, so my guess
> is that something is added later in configure that causes it to fail.
> I suggest looking at config.log to see what the actaul compiler
> messages are from these parts:
> 
> OSSH_CHECK_CFLAG_COMPILE([-mretpoline]) # clang
> OSSH_CHECK_LDFLAG_LINK([-Wl,-z,retpolineplt])
> 
> and the actual compiler output show up in config.log.
> 
> I wrote and tested this patch against the development versions of gcc
> and clang which was all that was available at the time, it's possible
> the released versions don't behave quite the same.
here's the complete config.log:
https://paste.fedoraproject.org/paste/WtZP~Oe1~es2ddeqCBtCqQ

the 'fun' appears to start at line# 652

	gcc-8: error: unrecognized command line option '-mretpoline'; did you
mean '-Wtrampolines'?

nooooo, no trampolines (is that a thing?) ;-)

at 1st quick look-thru, I'm just seeing that the flag failed, but not _why_.
yet.  looking closer now.

also, just fyi, during my testing I did try clang6 et al as well.  failed as
well, with different/additional errors.  didn't spend any further time on it
yet.

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openssh unix dev - Jun 2018 - vanilla build of 7.7p1 release on linux/4.17 fails with gcc8 @ "/usr/bin/ld: unrecognized option '-Wl,-z,retpolineplt'"

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vanilla build of 7.7p1 release on linux/4.17 fails with gcc8 @ "/usr/bin/ld: unrecognized option '-Wl,-z,retpolineplt'"

vanilla build of 7.7p1 release on linux/4.17 fails with gcc8 @ "/usr/bin/ld: unrecognized option '-Wl,-z,retpolineplt'"

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