Re: [PATCH] perf tools: Restore proper cwd on return from mnt ns

[Jiri Olsa <jolsa@redhat.com>]

On Mon, Nov 19, 2018 at 08:10:06AM -0800, Arnaldo Carvalho de Melo wrote:
> Em Thu, Nov 01, 2018 at 06:00:01PM +0100, Jiri Olsa escreveu:
> > Adding the current working directory to be part of the cookie
> > and restoring it in the nsinfo__mountns_exit call.
>  
> > diff --git a/tools/perf/util/namespaces.c b/tools/perf/util/namespaces.c
> > index cf8bd123cf73..fb0458b7e6aa 100644
> > --- a/tools/perf/util/namespaces.c
> > +++ b/tools/perf/util/namespaces.c
> 
> > @@ -199,9 +201,13 @@ void nsinfo__mountns_enter(struct nsinfo *nsi,
> >  	if (snprintf(curpath, PATH_MAX, "/proc/self/ns/mnt") >= PATH_MAX)
> >  		return;
>   
> > +	oldcwd = get_current_dir_name();
> 
> Breaks the build with bionic (Android), where get_current_dir_name() is
> not available:
> 
> /tmp/build/perf/libperf.a(libperf-in.o):hist.c:function nsinfo__mountns_enter: error: undefined reference to 'get_current_dir_name'
> collect2: error: ld returned 1 exit status
> Makefile.perf:534: recipe for target '/tmp/build/perf/perf' failed
> make[2]: *** [/tmp/build/perf/perf] Error 1
> Makefile.perf:206: recipe for target 'sub-make' failed
> make[1]: *** [sub-make] Error 2
> Makefile:69: recipe for target 'all' failed
> make: *** [all] Error 2
> make: Leaving directory '/git/linux/tools/perf'
> [root@seventh ~]# 
> 
> The container builds are ongoing, its possoble that this becomes an
> issue in uCLibc, wasn't on musl libc (Alpine Linux).

will check, thanks

jirka