[tip:perf/urgent] perf map: Consider PTI entry trampolines in rip_2objdump()

[tip-bot for Adrian Hunter]

Commit-ID:  97802f3b81dc0d1da0f89c498249547d73a01164
Gitweb:     https://git.kernel.org/tip/97802f3b81dc0d1da0f89c498249547d73a01164
Author:     Adrian Hunter <adrian.hunter@xxxxxxxxx>
AuthorDate: Tue, 5 Jun 2018 10:30:00 +0300
Committer:  Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitDate: Wed, 6 Jun 2018 12:52:06 -0300

perf map: Consider PTI entry trampolines in rip_2objdump()

perf tools uses map__rip_2objdump() to calculate objdump virtual addresses.
map__rip_2objdump() needs to be amended to deal with PTI entry trampolines.

Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Reported-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Tested-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Link: http://lkml.kernel.org/r/1528183800-21577-1-git-send-email-adrian.hunter@xxxxxxxxx
[ split from a larger patch ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
 tools/perf/util/map.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c
index 92abc8e248c5..89ac5b5dc218 100644
--- a/tools/perf/util/map.c
+++ b/tools/perf/util/map.c
@@ -449,6 +449,20 @@ int map__fprintf_srcline(struct map *map, u64 addr, const char *prefix,
  */
 u64 map__rip_2objdump(struct map *map, u64 rip)
 {
+	struct kmap *kmap = __map__kmap(map);
+
+	/*
+	 * vmlinux does not have program headers for PTI entry trampolines and
+	 * kcore may not either. However the trampoline object code is on the
+	 * main kernel map, so just use that instead.
+	 */
+	if (kmap && is_entry_trampoline(kmap->name) && kmap->kmaps && kmap->kmaps->machine) {
+		struct map *kernel_map = machine__kernel_map(kmap->kmaps->machine);
+
+		if (kernel_map)
+			map = kernel_map;
+	}
+
 	if (!map->dso->adjust_symbols)
 		return rip;