renegade-project/linux-next
2
0
Fork 0
mirror of https://github.com/edk2-porting/linux-next.git synced 2024-12-25 05:34:00 +08:00
Code

perf tools: Preserve eBPF maps when loading kcore

Browse Source 
We need to preserve eBPF maps even if they are covered by kcore, because
we need to access eBPF dso for source data.

Add the map_groups__merge_in function to do that.  It merges a map into
map_groups by splitting the new map within the existing map regions.

Suggested-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stanislav Fomichev <sdf@google.com>
Link: http://lkml.kernel.org/r/20190508132010.14512-9-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Jiri Olsa 2019-05-08 15:20:06 +02:00 committed by Arnaldo Carvalho de Melo
parent 8529f2e673
commit fb5a88d413
1 changed files with 93 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

97
tools/perf/util/symbol.c
View File

@ -1166,6 +1166,85 @@ static int kcore_mapfn(u64 start, u64 len, u64 pgoff, void *data)
return 0;
}
/*
* Merges map into map_groups by splitting the new map
* within the existing map regions.
*/
static int map_groups__merge_in(struct map_groups *kmaps, struct map *new_map)
{
struct map *old_map;
LIST_HEAD(merged);
for (old_map = map_groups__first(kmaps); old_map;
old_map = map_groups__next(old_map)) {
/* no overload with this one */
if (new_map->end < old_map->start ||
new_map->start >= old_map->end)
continue;
if (new_map->start < old_map->start) {
/*
* |new......
* |old....
*/
if (new_map->end < old_map->end) {
/*
* |new......| -> |new..|
* |old....| -> |old....|
*/
new_map->end = old_map->start;
} else {
/*
* |new.............| -> |new..| |new..|
* |old....| -> |old....|
*/
struct map *m = map__clone(new_map);
if (!m)
return -ENOMEM;
m->end = old_map->start;
list_add_tail(&m->node, &merged);
new_map->start = old_map->end;
}
} else {
/*
* |new......
* |old....
*/
if (new_map->end < old_map->end) {
/*
* |new..| -> x
* |old.........| -> |old.........|
*/
map__put(new_map);
new_map = NULL;
break;
} else {
/*
* |new......| -> |new...|
* |old....| -> |old....|
*/
new_map->start = old_map->end;
}
}
}
while (!list_empty(&merged)) {
old_map = list_entry(merged.next, struct map, node);
list_del_init(&old_map->node);
map_groups__insert(kmaps, old_map);
map__put(old_map);
}
if (new_map) {
map_groups__insert(kmaps, new_map);
map__put(new_map);
}
return 0;
}
static int dso__load_kcore(struct dso *dso, struct map *map,
const char *kallsyms_filename)
{
@ -1222,7 +1301,12 @@ 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)
/*
* We need to preserve eBPF maps even if they are
* covered by kcore, because we need to access
* eBPF dso for source data.
*/
if (old_map != map && !__map__is_bpf_prog(old_map))
map_groups__remove(kmaps, old_map);
old_map = next;
}
@ -1256,11 +1340,16 @@ static int dso__load_kcore(struct dso *dso, struct map *map,
map_groups__remove(kmaps, map);
map_groups__insert(kmaps, map);
map__put(map);
map__put(new_map);
} else {
map_groups__insert(kmaps, new_map);
/*
* Merge kcore map into existing maps,
* and ensure that current maps (eBPF)
* stay intact.
*/
if (map_groups__merge_in(kmaps, new_map))
goto out_err;
}
map__put(new_map);
}
if (machine__is(machine, "x86_64")) {