14v22 and gcc 10 produces a linker error

[fscheiner]

When trying to create GSI-OpenSSH 8.3p1 packages for Fedora 32 with the HPN patch(es) included - for gridcf/gct#108 - on the openSUSE Build Service (OBS) I get a linker error during build, see https://build.opensuse.org/package/live_build_log/home:frank_scheiner:gct-fedora-32/gsi-openssh/Fedora_32/x86_64 for details. The build process uses gcc 10:

[...]
[  212s] cc -o sshd sshd.o auth-rhosts.o auth-passwd.o audit.o audit-bsm.o audit-linux.o platform.o sshpty.o sshlogin.o servconf.o serverloop.o auth.o auth2.o auth-options.o session.o auth2-chall.o groupaccess.o auth-bsdauth.o auth2-hostbased.o auth2-kbdint.o auth2-none.o auth2-passwd.o auth2-pubkey.o monitor.o monitor_wrap.o auth-krb5.o auth2-gss.o gss-serv.o gss-serv-krb5.o kexgsss.o gss-serv-gsi.o loginrec.o auth-pam.o auth-shadow.o auth-sia.o md5crypt.o sftp-server.o sftp-common.o sandbox-null.o sandbox-rlimit.o sandbox-systrace.o sandbox-darwin.o sandbox-seccomp-filter.o sandbox-capsicum.o sandbox-pledge.o sandbox-solaris.o uidswap.o ssh-sk-client.o -L. -Lopenbsd-compat/  -pie -z relro -z now -fstack-protector-strong  -lssh -lopenbsd-compat -laudit -lpam -lsystemd  -lcrypto -ldl -lutil -lz  -lcrypt -lresolv -lselinux -lglobus_gss_assist -lglobus_gssapi_gsi -lglobus_common  -lpthread  
[  212s] /usr/bin/ld: session.o:/home/abuild/rpmbuild/BUILD/openssh-8.3p1/serverloop.h:25: multiple definition of `start_time'; serverloop.o:/home/abuild/rpmbuild/BUILD/openssh-8.3p1/serverloop.h:25: first defined here
[  212s] /usr/bin/ld: session.o:/home/abuild/rpmbuild/BUILD/openssh-8.3p1/serverloop.h:24: multiple definition of `fdout_bytes'; serverloop.o:/home/abuild/rpmbuild/BUILD/openssh-8.3p1/serverloop.h:24: first defined here
[  212s] /usr/bin/ld: session.o:/home/abuild/rpmbuild/BUILD/openssh-8.3p1/serverloop.h:23: multiple definition of `stdin_bytes'; serverloop.o:/home/abuild/rpmbuild/BUILD/openssh-8.3p1/serverloop.h:23: first defined here
[  213s] collect2: error: ld returned 1 exit status
[...]

It complains about multiple definitions of start_time, fdout_bytes and stdin_bytes. Both session.c and serverloop.c include serverloop.h where these seem to come from and this seems to make a problem with gcc 10 which defaults to -fno-common according to https://gcc.gnu.org/gcc-10/porting_to.html.

Actually the ssh struct (from packet.h) also defines vars with the same name. And the identically named vars in serverloop.h were not there in older versions of the HPN patches (e.g. 14v19), so are these really needed now?

[rapier1]

Fixed in the latest commits. This was also back ported to 8.0, 8.1, and 8.2.

[fscheiner]

@rapier1
Much obliged. :-) GSI-OpenSSH packages w/HPN for EPEL 8 (gsi-openssh-8.0p1-5.1) and Fedora 32 (gsi-openssh-8.3p1-5.1) were already updated. More to come in the future.