[PATCH 02/16] perf annotate: Reset the dso find_symbol cache when removing symbols

[Arnaldo Carvalho de Melo]

From: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>

The 'annotate' tool does some filtering in the entries in a DSO but
forgot to reset the cache done in dso__find_symbol(), cauxing a SEGV:

  [root@zoo ~]# perf annotate netlink_poll
  perf: Segmentation fault
  -------- backtrace --------
  perf[0x526ceb]
  /lib64/libc.so.6(+0x34960)[0x7faedfbe0960]
  perf(rb_erase+0x223)[0x499d63]
  perf[0x4213e9]
  perf[0x4bc123]
  perf[0x4bc621]
  perf[0x4bf26b]
  perf[0x4bc855]
  perf(perf_session__process_events+0x340)[0x4bddc0]
  perf(cmd_annotate+0x6bb)[0x421b5b]
  perf[0x479063]
  perf(main+0x60a)[0x42098a]
  /lib64/libc.so.6(__libc_start_main+0xf0)[0x7faedfbcbfe0]
  perf[0x420aa9]
  [0x0]
  [root@zoo ~]#

Fix it by reseting the find cache when removing symbols.

Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxx>
Cc: David Ahern <dsahern@xxxxxxxxx>
Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Stephane Eranian <eranian@xxxxxxxxxx>
Fixes: b685ac22b436 ("perf symbols: Add front end cache for DSO symbol lookup")
Link: http://lkml.kernel.org/n/tip-b2y9x46y0t8yem1ive41zqyp@xxxxxxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
 tools/perf/builtin-annotate.c |  1 +
 tools/perf/util/dso.h         |  2 ++
 tools/perf/util/symbol.c      | 10 ++++++++++
 3 files changed, 13 insertions(+)

diff --git a/tools/perf/builtin-annotate.c b/tools/perf/builtin-annotate.c
index a32a64ef08e2..8edc205ff9a7 100644
--- a/tools/perf/builtin-annotate.c
+++ b/tools/perf/builtin-annotate.c
@@ -67,6 +67,7 @@ static int perf_evsel__add_sample(struct perf_evsel *evsel,
 			rb_erase(&al->sym->rb_node,
 				 &al->map->dso->symbols[al->map->type]);
 			symbol__delete(al->sym);
+			dso__reset_find_symbol_cache(al->map->dso);
 		}
 		return 0;
 	}
diff --git a/tools/perf/util/dso.h b/tools/perf/util/dso.h
index c73276db6d6f..fc8db9c764ac 100644
--- a/tools/perf/util/dso.h
+++ b/tools/perf/util/dso.h
@@ -324,6 +324,8 @@ struct dso *__dsos__findnew(struct dsos *dsos, const char *name);
 struct dso *dsos__findnew(struct dsos *dsos, const char *name);
 bool __dsos__read_build_ids(struct list_head *head, bool with_hits);
 
+void dso__reset_find_symbol_cache(struct dso *dso);
+
 size_t __dsos__fprintf_buildid(struct list_head *head, FILE *fp,
 			       bool (skip)(struct dso *dso, int parm), int parm);
 size_t __dsos__fprintf(struct list_head *head, FILE *fp);
diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index 42e98ab5a9bb..46ae0532a8a6 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -441,6 +441,16 @@ static struct symbol *symbols__find_by_name(struct rb_root *symbols,
 	return &s->sym;
 }
 
+void dso__reset_find_symbol_cache(struct dso *dso)
+{
+	enum map_type type;
+
+	for (type = MAP__FUNCTION; type <= MAP__VARIABLE; ++type) {
+		dso->last_find_result[type].addr   = 0;
+		dso->last_find_result[type].symbol = NULL;
+	}
+}
+
 struct symbol *dso__find_symbol(struct dso *dso,
 				enum map_type type, u64 addr)
 {
-- 
2.1.0

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