On Tue, Apr 23, 2019 at 12:32:12PM +0300, Adrian Hunter wrote: > On 16/04/19 7:01 PM, Jiri Olsa wrote: > > Maps in kcore do not cover bpf maps, so we can't just > > remove everything. Keeping all kernel maps, which are > > not covered by kcore maps. > > Memory for jited-bpf is allocated from the same area that is used for > modules. In the case of /proc/kcore, that entire area is mapped, so there > won't be any bpf-maps that are not covered. For copies of kcore made by > 'perf buildid-cache' the same would be true for any bpf that got allocated > in between modules. > > But shouldn't the bpf map supersede the kcore map for the address range that > it maps? I guess that would mean splitting the kcore map, truncating the > first piece and inserting the bpf map in between.
I haven't considered it could get in between modules, I think you're right and we need to cut kcore maps in case bpf is mapped within.. I'll submit new version thanks, jirka > > > > > Link: http://lkml.kernel.org/n/[email protected] > > Signed-off-by: Jiri Olsa <[email protected]> > > --- > > tools/perf/util/symbol.c | 14 +++++++++++++- > > 1 file changed, 13 insertions(+), 1 deletion(-) > > > > diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c > > index 5cbad55cd99d..96738a7a8c14 100644 > > --- a/tools/perf/util/symbol.c > > +++ b/tools/perf/util/symbol.c > > @@ -1166,6 +1166,18 @@ static int kcore_mapfn(u64 start, u64 len, u64 > > pgoff, void *data) > > return 0; > > } > > > > +static bool in_kcore(struct kcore_mapfn_data *md, struct map *map) > > +{ > > + struct map *iter; > > + > > + list_for_each_entry(iter, &md->maps, node) { > > + if ((map->start >= iter->start) && (map->start < iter->end)) > > + return true; > > + } > > + > > + return false; > > +} > > + > > static int dso__load_kcore(struct dso *dso, struct map *map, > > const char *kallsyms_filename) > > { > > @@ -1222,7 +1234,7 @@ static int dso__load_kcore(struct dso *dso, struct > > map *map, > > while (old_map) { > > struct map *next = map_groups__next(old_map); > > > > - if (old_map != map) > > + if (old_map != map && !in_kcore(&md, old_map)) > > map_groups__remove(kmaps, old_map); > > old_map = next; > > } > > >
