[PATCH tip/perf/core] perf probe: Load map before glob matching

From: Wang Nan
Date: Fri May 15 2015 - 08:15:24 EST


Commit 4c859351226c920b227fec040a3b447f0d482af3 ("perf probe: Support
glob wildcards for function name") introduces a problem:

# /root/perf probe kmem_cache_free
Failed to find symbol kmem_cache_free in kernel
Error: Failed to add events.

The reason is the replacement of map__for_each_symbol_by_name() (by
map__for_each_symbol()). Although their names are similay,
map__for_each_symbol doesn't call map__load() and dso__sort_by_name()
before searching. The missing of map__load() causes this problem
because it search symbol before load dso map.

This patch ensures map__load() is called before using
map__for_each_symbol().

After this patch:

# /root/perf probe kmem_cache_free
Added new event:
probe:kmem_cache_free (on kmem_cache_free%return)

You can now use it in all perf tools, such as:

perf record -e probe:kmem_cache_free -aR sleep 1

Signed-off-by: Wang Nan <wangnan0@xxxxxxxxxx>
---
tools/perf/util/probe-event.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index 2399dc4..1faa1e6 100644
--- a/tools/perf/util/probe-event.c
+++ b/tools/perf/util/probe-event.c
@@ -2499,6 +2499,9 @@ static int find_probe_functions(struct map *map, char *name)
struct symbol *sym;
struct rb_node *tmp;

+ if (map__load(map, NULL) < 0)
+ return 0;
+
map__for_each_symbol(map, sym, tmp) {
if (strglobmatch(sym->name, name))
found++;
--
1.8.3.4

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