Re: [PATCH 3/3] perf annotate: Try chroot filename for objdump

[Arnaldo Carvalho de Melo]

Em Tue, Feb 01, 2022 at 11:54:14AM -0800, Namhyung Kim escreveu:
> Hi Jiri,
> 
> On Mon, Jan 31, 2022 at 11:23 AM Jiri Olsa <jolsa@xxxxxxxxxx> wrote:
> >
> > On Fri, Jan 28, 2022 at 12:39:50PM -0800, Namhyung Kim wrote:
> > > Likewise, it should use a proper name in case the task runs under
> > > chroot.  The child_process.err was needed to set to -1 to show error
> > > messages properly in TUI.
> > >
> > > Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
> > > ---
> > >  tools/perf/util/annotate.c | 11 +++++++++++
> > >  1 file changed, 11 insertions(+)
> > >
> > > diff --git a/tools/perf/util/annotate.c b/tools/perf/util/annotate.c
> > > index 01900689dc00..e4c641b240df 100644
> > > --- a/tools/perf/util/annotate.c
> > > +++ b/tools/perf/util/annotate.c
> > > @@ -33,6 +33,7 @@
> > >  #include "string2.h"
> > >  #include "util/event.h"
> > >  #include "arch/common.h"
> > > +#include "namespaces.h"
> > >  #include <regex.h>
> > >  #include <pthread.h>
> > >  #include <linux/bitops.h>
> > > @@ -1696,6 +1697,15 @@ static int dso__disassemble_filename(struct dso *dso, char *filename, size_t fil
> > >                * DSO is the same as when 'perf record' ran.
> > >                */
> > >               __symbol__join_symfs(filename, filename_size, dso->long_name);
> > > +
> > > +             if (access(filename, R_OK) && errno == ENOENT && dso->nsinfo) {
> > > +                     char *new_name = filename_with_chroot(dso->nsinfo->pid,
> > > +                                                           filename);
> > > +                     if (new_name) {
> > > +                             strlcpy(filename, new_name, filename_size);
> > > +                             free(new_name);
> > > +                     }
> > > +             }
> > >       }
> > >
> > >       free(build_id_path);
> > > @@ -2036,6 +2046,7 @@ static int symbol__disassemble(struct symbol *sym, struct annotate_args *args)
> > >       memset(&objdump_process, 0, sizeof(objdump_process));
> > >       objdump_process.argv = objdump_argv;
> > >       objdump_process.out = -1;
> > > +     objdump_process.err = -1;
> >
> > is this unrelated fix?
> 
> Right, it's unrelated.  Maybe I can split it if Arnaldo wants.

Yes, please split.
 
> >
> > otherwise the whole patchset looks good to me
> >
> > I guess we'd need to add something like PERF_RECORD_CHROOT to
> > handle and instrument sys_chroot to handle this completely?
> 
> Are you talking about an env variable?  Maybe we can track
> chroot syscall.  But it needs to be task-specific rather than a
> global setup.
> 
> As it hasn't been an issue so far, I think it's ok to have it as
> a fallback right now.
> 
> >
> > Acked-by: Jiri Olsa <jolsa@xxxxxxxxxx>
> 
> Thanks for your review!

Indeed, thank you guys!

> Namhyung
> 
> 
> >
> > >       if (start_command(&objdump_process)) {
> > >               pr_err("Failure starting to run %s\n", command);
> > >               err = -1;
> > > --
> > > 2.35.0.rc2.247.g8bbb082509-goog
> > >
> >

-- 

- Arnaldo