3.0.7: build fails (and compile time warnings)

[kloczek]

Looks like 3.0.7 is not gcc 12.0.1 ready
Summary stats:

[tkloczko@devel-g2v SPECS]$ rpmbuild -ba --with check --with failing_tests audit.spec --quiet 2>&1 | grep -- -W | sed 's/.*\[//; s/\]//' | sort | uniq -c | sort -nr
      8 -Wunused-but-set-variable
      5 -Wdiscarded-qualifiers
      3 -Wunused-result
      2 -Wunused-value
      1 -Wreturn-type
      1 -Woverflow
      1 -Wdeprecated-declarations
      1 -Waddress

end extracted stderr on running make -k

../lib/gen_tables.c:89:22: warning: overflow in conversion from 'long long unsigned int' to 'int' changes value from '4294967296' to '0' [-Woverflow]
   89 | #define _S(VAL, S) { (VAL), (S), 0, 0 },
      |                      ^
./clone-flagtab.h:47:1: note: in expansion of macro '_S'
   47 | _S(0x100000000ULL,      "CLONE_CLEAR_SIGHAND")
      | ^~
zos-remote-plugin.c: In function 'submission_thread_main':
zos-remote-plugin.c:106:30: warning: passing argument 1 of 'zos_remote_init' discards 'volatile' qualifier from pointer target type [-Wdiscarded-qualifiers]
  106 |         rc = zos_remote_init(&zos_remote_inst, conf.server,
      |                              ^~~~~~~~~~~~~~~~
In file included from zos-remote-log.h:27,
                 from zos-remote-plugin.c:44:
zos-remote-ldap.h:297:21: note: expected 'ZOS_REMOTE *' {aka 'struct opaque *'} but argument is of type 'volatile ZOS_REMOTE *' {aka 'volatile struct opaque *'}
  297 | int zos_remote_init(ZOS_REMOTE *, const char *, int, const char *,
      |                     ^~~~~~~~~~~~
zos-remote-plugin.c:128:39: warning: passing argument 1 of 'submit_request_s' discards 'volatile' qualifier from pointer target type [-Wdiscarded-qualifiers]
  128 |                 rc = submit_request_s(&zos_remote_inst, ber);
      |                                       ^~~~~~~~~~~~~~~~
zos-remote-ldap.h:309:22: note: expected 'ZOS_REMOTE *' {aka 'struct opaque *'} but argument is of type 'volatile ZOS_REMOTE *' {aka 'volatile struct opaque *'}
  309 | int submit_request_s(ZOS_REMOTE *, BerElement *);
      |                      ^~~~~~~~~~~~
zos-remote-plugin.c:141:28: warning: passing argument 1 of 'zos_remote_destroy' discards 'volatile' qualifier from pointer target type [-Wdiscarded-qualifiers]
  141 |         zos_remote_destroy(&zos_remote_inst);
      |                            ^~~~~~~~~~~~~~~~
zos-remote-ldap.h:303:25: note: expected 'ZOS_REMOTE *' {aka 'struct opaque *'} but argument is of type 'volatile ZOS_REMOTE *' {aka 'volatile struct opaque *'}
  303 | void zos_remote_destroy(ZOS_REMOTE *);
      |                         ^~~~~~~~~~~~
ev.c:2146:31: warning: 'ev_default_loop_ptr' initialized and declared 'extern'
 2146 |   EV_API_DECL struct ev_loop *ev_default_loop_ptr = 0; /* needs to be initialised to make it a definition despite extern */
      |                               ^~~~~~~~~~~~~~~~~~~
In file included from ev.c:3108:
ev_iouring.c: In function 'iouring_sqe_submit':
ev_iouring.c:300:1: warning: no return statement in function returning non-void [-Wreturn-type]
  300 | }
      | ^
In file included from ev.c:222:
ev_iouring.c: In function 'iouring_fork':
ev.h:180:20: warning: left-hand operand of comma expression has no effect [-Wunused-value]
  180 | # define EV_A_ EV_A,                              /* a loop as first of multiple arguments */
      |                    ^
ev.h:698:52: note: in definition of macro 'ev_io_set'
  698 | #define ev_io_set(ev,fd_,events_)            do { (ev)->fd = (fd_); (ev)->events = (events_) | EV__IOFDSET; } while (0)
      |                                                    ^~
ev_iouring.c:428:16: note: in expansion of macro 'EV_A_'
  428 |   ev_io_set   (EV_A_ &iouring_tfd_w, iouring_tfd, EV_READ);
      |                ^~~~~
ev.h:180:20: warning: left-hand operand of comma expression has no effect [-Wunused-value]
  180 | # define EV_A_ EV_A,                              /* a loop as first of multiple arguments */
      |                    ^
ev.h:698:70: note: in definition of macro 'ev_io_set'
  698 | #define ev_io_set(ev,fd_,events_)            do { (ev)->fd = (fd_); (ev)->events = (events_) | EV__IOFDSET; } while (0)
      |                                                                      ^~
ev_iouring.c:428:16: note: in expansion of macro 'EV_A_'
  428 |   ev_io_set   (EV_A_ &iouring_tfd_w, iouring_tfd, EV_READ);
      |                ^~~~~
auditd.c: In function 'reconfig_ready':
auditd.c:585:9: warning: ignoring return value of 'write' declared with attribute 'warn_unused_result' [-Wunused-result]
  585 |         write(pipefds[1], msg, strlen(msg));
      |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
auditd.c: In function 'pipe_handler':
auditd.c:577:9: warning: ignoring return value of 'read' declared with attribute 'warn_unused_result' [-Wunused-result]
  577 |         read(pipefds[0], buf, sizeof(buf));
      |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
ausearch.c: In function 'process_stdin':
ausearch.c:524:13: warning: 'siginterrupt' is deprecated: Use sigaction with SA_RESTART instead [-Wdeprecated-declarations]
  524 |             siginterrupt(SIGALRM, 1) == -1)
      |             ^~~~~~~~~~~~
In file included from /usr/include/sys/param.h:28,
                 from ausearch.c:37:
/usr/include/signal.h:324:12: note: declared here
  324 | extern int siginterrupt (int __sig, int __interrupt) __THROW
      |            ^~~~~~~~~~~~
auditd-event.c: In function 'fix_disk_permissions':
auditd-event.c:1060:9: warning: ignoring return value of 'chown' declared with attribute 'warn_unused_result' [-Wunused-result]
 1060 |         chown(dir, 0, config->log_group ? config->log_group : 0);
      |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
auditd-listen.c: In function 'client_ack':
auditd-listen.c:500:21: warning: variable 'rc' set but not used [-Wunused-but-set-variable]
  500 |                 int rc, mlen;
      |                     ^~
auditd-listen.c: In function 'client_message':
auditd-listen.c:546:19: warning: variable 'mver' set but not used [-Wunused-but-set-variable]
  546 |         int hver, mver;
      |                   ^~~~
auditd-listen.c:546:13: warning: variable 'hver' set but not used [-Wunused-but-set-variable]
  546 |         int hver, mver;
      |             ^~~~
auditd-listen.c:545:24: warning: variable 'mlen' set but not used [-Wunused-but-set-variable]
  545 |         uint32_t type, mlen, seq;
      |                        ^~~~
auditd-listen.c: In function 'auditd_tcp_client_handler':
auditd-listen.c:678:27: warning: variable 'mver' set but not used [-Wunused-but-set-variable]
  678 |                 int hver, mver;
      |                           ^~~~
auditd-listen.c:678:21: warning: variable 'hver' set but not used [-Wunused-but-set-variable]
  678 |                 int hver, mver;
      |                     ^~~~
auditd-listen.c:677:37: warning: variable 'seq' set but not used [-Wunused-but-set-variable]
  677 |                 uint32_t type, len, seq;
      |                                     ^~~
auditd-listen.c:677:26: warning: variable 'type' set but not used [-Wunused-but-set-variable]
  677 |                 uint32_t type, len, seq;
      |                          ^~~~
../../../bindings/python/auparse_python.c: In function 'AuParser_init':
../../../bindings/python/auparse_python.c:375:31: warning: assignment discards 'const' qualifier from pointer target type [-Wdiscarded-qualifiers]
  375 |                 if ((files[i] = PYSTR_ASSTRING(item)) == NULL) {
      |                               ^
../../../bindings/python/auparse_python.c:418:33: warning: assignment discards 'const' qualifier from pointer target type [-Wdiscarded-qualifiers]
  418 |                 if ((buffers[i] = PYSTR_ASSTRING(item)) == NULL) {
      |                                 ^
Deprecated command line option: -modern. This option is now always on.
audit_wrap.c: In function '_wrap_audit_rule_data_buf_set':
audit_wrap.c:4698:7: warning: the comparison will always evaluate as 'true' for the address of 'buf' will never be NULL [-Waddress]
 4698 |   if (arg1->buf) free((char*)arg1->buf);
      |       ^~~~
In file included from ../../../lib/../lib/libaudit.h:42,
                 from audit_wrap.c:2729:
/usr/include/linux/audit.h:517:25: note: 'buf' declared here
  517 |         char            buf[];  /* string fields buffer */
      |                         ^~~
audit_wrap.c:4701:17: error: cast specifies array type
 4701 |     arg1->buf = (char [])(char *)memcpy(malloc((size)*sizeof(char)), (const char *)(arg2), sizeof(char)*(size));
      |                 ^
audit_wrap.c:4701:15: error: invalid use of flexible array member
 4701 |     arg1->buf = (char [])(char *)memcpy(malloc((size)*sizeof(char)), (const char *)(arg2), sizeof(char)*(size));
      |               ^
audit_wrap.c:4703:15: error: invalid use of flexible array member
 4703 |     arg1->buf = 0;
      |               ^
make[4]: *** [Makefile:518: _audit_la-audit_wrap.lo] Error 1
make[4]: Target 'all' not remade because of errors.

[stevegrubb]

This is known. It's being worked as https://bugzilla.redhat.com/show_bug.cgi?id=2049096
The main issue is SWIG generates code that gcc 12 doesn't like.
In general, I'd rather have pull requests fixing warnings. I have my own build logs with these same warnings. :-)

[kloczek]

Did someone opened swig ticket?

[stevegrubb]

I think I'll reopen this issue now that I know the root cause

Upstream SWIG has not yet been contacted. SWIG has 400 open issues - which is discouraging. The root cause of the problem is this:

KSPP/linux#78

SWIG apparently doesn't know how to generate good code from a flexible array member. The options are:

1. Contact upstream SWIG and wait
2. Rewrite the bindings not to use SWIG (like the auparse bindings)
3. Ask upstream kernel to go back to buf[0];
4. Do some build time patch to copy audit.h to the build directory and use the gcc buf[0] extension

4 would be a short term fix. 2 would probably be the only viable long term fix. And 2 is going to take some time.

[stevegrubb]

A workaround was posted to the Linux audit mail list:
https://listman.redhat.com/archives/linux-audit/2022-February/msg00085.html
Any compiler warnings will be fixed as normal maintenance. Pull requests are welcome.

I'll leave this issue open a little while longer in case someone else has the same problem.

[stevegrubb]

OK, the mail list has pointers to patches and explanation of problems. I am going to close this. The ultimate solution is rewriting the python bindings.