[PATCH 1/4] perf symbols: add dso__insert_symbol function

Chris Phlipot
2016-05-11T02:04:37Z

The current method for inserting symbols is to use the symbols__insert
function. However symbols__insert does not update the dso symbol cache.
This causes problems in the following scenario:

1. symbol not found at ip using dso__find_symbol

2. symbol inserted at ip using the existing symbols__insert function

3. symbol still not found at ip using dso__find_symbol because cache isn't
updated. This is undesired behavior.

The undesired behavior in (3) is addressed by creating a new function,
dso__insert_symbol to both insert the symbol and update the symbol cache
if necessary.

If dso__insert_symbol is used in (2) instead of symbols__insert, then the
undesired behavior in (3) is avoided.

Signed-off-by: Chris Phlipot <cphlipot0@gmail.com>
---
tools/perf/util/symbol.c | 12 ++++++++++++
tools/perf/util/symbol.h | 3 +++
2 files changed, 15 insertions(+)

diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index 2946295..21af8e8 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -413,6 +413,18 @@ void dso__reset_find_symbol_cache(struct dso *dso)
}
}

+void dso__insert_symbol(struct dso *dso, enum map_type type, struct symbol *sym)
+{
+ symbols__insert(&dso->symbols[type], sym);
+
+ /* update the symbol cache if necessary */
+ if (dso->last_find_result[type].addr >= sym->start &&
+ (dso->last_find_result[type].addr < sym->end ||
+ sym->start == sym->end)) {
+ dso->last_find_result[type].symbol = sym;
+ }
+}
+
struct symbol *dso__find_symbol(struct dso *dso,
enum map_type type, u64 addr)
{
diff --git a/tools/perf/util/symbol.h b/tools/perf/util/symbol.h
index 07211c2..2b5e4ed 100644
--- a/tools/perf/util/symbol.h
+++ b/tools/perf/util/symbol.h
@@ -246,6 +246,9 @@ int __dso__load_kallsyms(struct dso *dso, const char *filename, struct map *map,
int dso__load_kallsyms(struct dso *dso, const char *filename, struct map *map,
symbol_filter_t filter);

+void dso__insert_symbol(struct dso *dso, enum map_type type,
+ struct symbol *sym);
+
struct symbol *dso__find_symbol(struct dso *dso, enum map_type type,
u64 addr);
struct symbol *dso__find_symbol_by_name(struct dso *dso, enum map_type type,
--
2.7.4