[CRIU] criu build failures with glibc-2.25.90 (fedora rawhide)

[Adrian Reber]

Trying to upgrade the criu package on Fedora I ran into a build failure
on Fedora rawhide (development branch).

https://kojipkgs.fedoraproject.org//work/tasks/3909/20233909/build.log

The next pre-release of glibc (2.25.90) is part of that Fedora branch
and glibc removed SIGUNUSED from bits/signum.h:

criu/cr-restore.c: In function 'sig_fatal':
criu/cr-restore.c:900:9: error: 'SIGUNUSED' undeclared (first use in this function); did you mean 'SI_USER'?
   (1 << SIGUNUSED)|\
         ^
criu/cr-restore.c:907:41: note: in expansion of macro 'SIG_FATAL_MASK'
  return (sig > 0) && (sig < SIGMAX) && (SIG_FATAL_MASK & (1UL << sig));
                                         ^~~~~~~~~~~~~~
criu/cr-restore.c:900:9: note: each undeclared identifier is reported only once for each function it appears in
   (1 << SIGUNUSED)|\
         ^
criu/cr-restore.c:907:41: note: in expansion of macro 'SIG_FATAL_MASK'
  return (sig > 0) && (sig < SIGMAX) && (SIG_FATAL_MASK & (1UL << sig));
                                         ^~~~~~~~~~~~~~
criu/cr-restore.c:908:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^
make[2]: *** [/builddir/build/BUILD/criu-3.2.1/scripts/nmk/scripts/build.mk:111: criu/cr-restore.o] Error 1
make[1]: *** [criu/Makefile:73: criu/built-in.o] Error 2
make: *** [Makefile:218: criu] Error 2

According to a glibc developer SIGSYS returns the same value as
SIGUNUSED. Not sure if that is the right fix for criu

https://sourceware.org/git/gitweb.cgi?p=glibc.git;a=commitdiff;h=8082d91e1c449e0cb137468b731004a5e605c8c6


diff --git a/criu/cr-restore.c b/criu/cr-restore.c
index cfc8f504..7e11c8c5 100644
--- a/criu/cr-restore.c
+++ b/criu/cr-restore.c
@@ -897,7 +897,6 @@ static void zombie_prepare_signals(void)
                (1 << SIGPOLL)  |\
                (1 << SIGIO)    |\
                (1 << SIGSYS)   |\
-               (1 << SIGUNUSED)|\
                (1 << SIGSTKFLT)|\
                (1 << SIGPWR)    \
        )
diff --git a/test/zdtm/static/pthread01.c b/test/zdtm/static/pthread01.c
index 52f849c0..2520fcfe 100644
--- a/test/zdtm/static/pthread01.c
+++ b/test/zdtm/static/pthread01.c
@@ -43,7 +43,7 @@ static char *decode_signal(const sigset_t *s, char *buf)
        COLLECT(SIGTERM); COLLECT(SIGSTKFLT); COLLECT(SIGCHLD); COLLECT(SIGCONT); COLLECT(SIGSTOP);
        COLLECT(SIGTSTP); COLLECT(SIGTTIN); COLLECT(SIGTTOU); COLLECT(SIGURG); COLLECT(SIGXCPU);
        COLLECT(SIGXFSZ); COLLECT(SIGVTALRM); COLLECT(SIGPROF); COLLECT(SIGWINCH); COLLECT(SIGIO);
-       COLLECT(SIGPOLL); COLLECT(SIGPWR); COLLECT(SIGSYS); COLLECT(SIGUNUSED);
+       COLLECT(SIGPOLL); COLLECT(SIGPWR); COLLECT(SIGSYS);
 #undef COLLECT
 
        return buf;


I can submit a real patch if this is the right approach.

With this patch I get following zdtm result:

################### 10 TEST(S) FAILED (TOTAL 294/SKIPPED 26) ###################
 * zdtm/static/del_standalone_un(h)
 * zdtm/static/cgroup_stray(h)
 * zdtm/static/cgroup02(h)
 * zdtm/static/cgroupns(h)
 * zdtm/static/cgroup01(h)
 * zdtm/static/cgroup00(h)
 * zdtm/static/socket-tcp-syn-sent(h)
 * zdtm/static/cgroup04(h)
 * zdtm/static/deleted_unix_sock(h)
 * zdtm/static/cgroup03(h)
##################################### FAIL #####################################

All cgroup related tests are hanging and I had to kill criu
manually.

		Adrian