[PATCH] perf tools: Fix kernel maps for kcore and eBPF

From: Adrian Hunter
Date: Tue Jun 02 2020 - 07:25:43 EST


Adjust pgoff also when moving a map's start address.

Example with v5.4.34 based kernel:

Before:

$ sudo tools/perf/perf record -a --kcore -e intel_pt//k sleep 1
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 1.958 MB perf.data ]
$ sudo tools/perf/perf script --itrace=e >/dev/null
Warning:
961 instruction trace errors

After:

$ sudo tools/perf/perf script --itrace=e >/dev/null
$

Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Fixes: fb5a88d4131a ("perf tools: Preserve eBPF maps when loading kcore")
Cc: stable@xxxxxxxxxxxxxxx
---
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 57cbe7a29868..5ddf84dcbae7 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -1224,6 +1224,7 @@ int maps__merge_in(struct maps *kmaps, struct map *new_map)

m->end = old_map->start;
list_add_tail(&m->node, &merged);
+ new_map->pgoff += old_map->end - new_map->start;
new_map->start = old_map->end;
}
} else {
@@ -1244,6 +1245,7 @@ int maps__merge_in(struct maps *kmaps, struct map *new_map)
* |new......| -> |new...|
* |old....| -> |old....|
*/
+ new_map->pgoff += old_map->end - new_map->start;
new_map->start = old_map->end;
}
}
--
2.17.1