[PATCH 1/6] perf tools: Fix split_kallsyms_for_kcore for trampoline symbols

Adrian Hunter
2019-01-09T09:20:50Z

Kallsyms symbols do not have a size, so the size becomes the distance to
the next symbol. Consequently the recently added trampoline symbols end up
with large sizes because the trampolines are some distance from one another
and the main kernel map. However, symbols that end outside their map can
disrupt the symbol tree because, after mapping, it can appear incorrectly
that they overlap other symbols. Add logic to truncate symbol size to the
end of the corresponding map.

Fixes: d83212d5dd67 ("kallsyms, x86: Export addresses of PTI entry trampolines")
Cc: stable@vger.kernel.org
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
tools/perf/util/symbol.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index 01f2c7385e38..baf6498d1835 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -709,6 +709,8 @@ static int map_groups__split_kallsyms_for_kcore(struct map_groups *kmaps, struct
}

pos->start -= curr_map->start - curr_map->pgoff;
+ if (pos->end > curr_map->end)
+ pos->end = curr_map->end;
if (pos->end)
pos->end -= curr_map->start - curr_map->pgoff;
symbols__insert(&curr_map->dso->symbols, pos);
--
2.17.1