Re: [PATCH] perf session: Fix undeclared 'oe'

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Mon, Apr 30, 2018 at 10:20:08AM -0700, Greg Kroah-Hartman wrote:
> On Mon, Apr 30, 2018 at 02:11:55PM -0300, Murilo Opsfelder Araujo wrote:
> > On 04/11/2018 05:21 PM, Murilo Opsfelder Araújo wrote:
> > > On 04/11/2018 04:33 PM, Greg Kroah-Hartman wrote:
> > >> On Wed, Apr 11, 2018 at 03:41:35PM -0300, Murilo Opsfelder Araujo wrote:
> > >>> Using linux-3.18.y branch, perf build fails with the following:
> > >>>
> > >>>     $ make -s -j16 -C tools/perf V=1 WERROR=0 NO_LIBUNWIND=1 HAVE_CPLUS_DEMANGLE=1 NO_GTK2=1 NO_LIBNUMA=1 NO_STRLCPY=1 NO_BIONIC=1 prefix=/usr DESTDIR=/tmp/builddir/build all
> > >>>     [...]
> > >>>     util/session.c: In function ‘__perf_session__process_pipe_events’:
> > >>>     util/session.c:1093:36: error: ‘oe’ undeclared (first use in this function)
> > >>>       ordered_events__set_copy_on_queue(oe, true);
> > >>>                                         ^
> > >>>     util/session.c:1093:36: note: each undeclared identifier is reported only once for each function it appears in
> > >>>
> > >>> This patch fixes it for linux-3.18.y branch.
> > >>
> > >> Why is this failing now?  Has it always been broken?  Is there an
> > >> upstream patch that fixed this instead?
> > >>
> > > 
> > > Hi, Greg.
> > > 
> > > We've caught this build issue this week. I'm not sure since when it's
> > > failing.
> > > 
> > > The upstream patch that fixes this is:
> > > 
> > > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=fa713a4eb9cebe5dec71b1bd11429603e17d841d
> > > 
> > > commit fa713a4eb9cebe5dec71b1bd11429603e17d841d
> > > Author: Arnaldo Carvalho de Melo <acme@redhat.com>
> > > Date:   Tue Mar 3 11:48:12 2015 -0300
> > > 
> > >     perf ordered_events: Untangle from perf_session
> > > 
> > > But it doesn't apply straightforwardly.  At
> > > fa713a4eb9cebe5dec71b1bd11429603e17d841d, perf API and perf_evlist
> > > struct are slightly different from linux-3.18.y.
> > > 
> > > A list of upstream patches for a clean backport (I think) would be:
> > > 
> > > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=54245fdc357613633954bfd38cffb71cb9def067
> > > 
> > > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=75be989a7a18e9666efd92b846ee48bed79e8086
> > > 
> > > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=313e53b08e99b1dacf9ea2b0fbe97890db1ea95f
> > > 
> > > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=9fa8727aa4d98d35ca50ef9cd8a50c6468af921d
> > > 
> > > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=fa713a4eb9cebe5dec71b1bd11429603e17d841d
> > > 
> > > Do you prefer all above patches backported to linux-3.18.y or just the
> > > one-line fix I sent?
> > > 
> > >>> Fixes: 95b33b99cdd6 ("perf inject: Copy events when reordering events in pipe mode")
> > >>
> > >> Was this just a bad backport?
> > > 
> > > Some patches were left behind, I guess.
> > > 
> > >>
> > >> thanks,
> > >>
> > >> greg k-h
> > 
> > Hi, Greg.
> > 
> > I've realized that perf build on v3.18.107 is still broken, actually, it
> > got a bit worse than v3.18.104.
> > 
> > After applying my patch to fix the undeclared 'oe', perf build fails
> > with the following errors:
> > 
> > $ make -s -j16 -C tools/perf V=1 WERROR=0 NO_LIBUNWIND=1
> > HAVE_CPLUS_DEMANGLE=1 NO_GTK2=1 NO_LIBNUMA=1 NO_STRLCPY=1 NO_BIONIC=1
> > prefix=/usr DESTDIR=/tmp/builddir/build all
> > [...]
> > tests/code-reading.c: In function ‘read_object_code’:
> > tests/code-reading.c:145:19: error: ‘KMOD_DECOMP_LEN’ undeclared (first
> > use in this function)
> >   char decomp_name[KMOD_DECOMP_LEN];
> >                    ^
> > tests/code-reading.c:145:19: note: each undeclared identifier is
> > reported only once for each function it appears in
> > tests/code-reading.c:208:2: warning: implicit declaration of function
> > ‘dso__needs_decompress’ [-Wimplicit-function-declaration]
> >   if (dso__needs_decompress(al.map->dso)) {
> >   ^
> > tests/code-reading.c:208:2: warning: nested extern declaration of
> > ‘dso__needs_decompress’ [-Wnested-externs]
> > tests/code-reading.c:209:3: warning: implicit declaration of function
> > ‘dso__decompress_kmodule_path’ [-Wimplicit-function-declaration]
> >    if (dso__decompress_kmodule_path(al.map->dso, objdump_name,
> >    ^
> > tests/code-reading.c:209:3: warning: nested extern declaration of
> > ‘dso__decompress_kmodule_path’ [-Wnested-externs]
> > tests/code-reading.c:145:7: warning: unused variable ‘decomp_name’
> > [-Wunused-variable]
> >   char decomp_name[KMOD_DECOMP_LEN];
> >        ^
> > 
> > Apparently, this was introduced by commit
> > 091b3b4ba55daf8b28f40794aefdaa0bdb5af7a1:
> > 
> > commit 091b3b4ba55daf8b28f40794aefdaa0bdb5af7a1
> > Author: Namhyung Kim <namhyung@kernel.org>
> > Date:   Thu Jun 8 16:31:07 2017 +0900
> > 
> >     perf tests: Decompress kernel module before objdump
> > 
> > 
> > Namhyung, are you fixing this?
> 
> Ugh, I can fix this, I just did so on 4.4.y...

Nope, this is a mess.  When did perf last build on 3.18.y?  It really
looks like no one cares about it...

greg k-h