perf tools: Fix split_kallsyms_for_kcore() for trampoline symbols

mainline inclusion
from mainline-5.0
commit d6d457451eb9
category: bugfix
bugzilla: 11724
CVE: NA

-------------------------------------------------

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.
Signed-off-by: NAdrian Hunter <adrian.hunter@intel.com>
Acked-by: NJiri Olsa <jolsa@kernel.org>
Cc: stable@vger.kernel.org
Fixes: d83212d5 ("kallsyms, x86: Export addresses of PTI entry trampolines")
Link: http://lkml.kernel.org/r/20190109091835.5570-2-adrian.hunter@intel.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: NWei Li <liwei391@huawei.com>
Reviewed-by: NCheng Jian <cj.chengjian@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

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);