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authorKrister Johansen2017-01-06 07:23:31 +0100
committerArnaldo Carvalho de Melo2017-02-02 15:39:09 +0100
commitaa33b9b9a2ebb00d33c83a5312d4fbf2d5aeba36 (patch)
treebb0805b62c31bfee44ae018eac68214c0e40d1e1 /tools/perf/util/hist.c
parentperf diff: Fix -o/--order option behavior (again) (diff)
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perf callchain: Reference count maps
If dso__load_kcore frees all of the existing maps, but one has already been attached to a callchain cursor node, then we can get a SIGSEGV in any function that happens to try to use this invalid cursor. Use the existing map refcount mechanism to forestall cleanup of a map until the cursor iterates past the node. Signed-off-by: Krister Johansen <kjlx@templeofstupid.com> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: stable@kernel.org Fixes: 84c2cafa2889 ("perf tools: Reference count struct map") Link: http://lkml.kernel.org/r/20170106062331.GB2707@templeofstupid.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/util/hist.c')
-rw-r--r--tools/perf/util/hist.c7
1 files changed, 7 insertions, 0 deletions
diff --git a/tools/perf/util/hist.c b/tools/perf/util/hist.c
index 6770a9645609..7d1b7d33e644 100644
--- a/tools/perf/util/hist.c
+++ b/tools/perf/util/hist.c
@@ -1,6 +1,7 @@
#include "util.h"
#include "build-id.h"
#include "hist.h"
+#include "map.h"
#include "session.h"
#include "sort.h"
#include "evlist.h"
@@ -1019,6 +1020,10 @@ int hist_entry_iter__add(struct hist_entry_iter *iter, struct addr_location *al,
int max_stack_depth, void *arg)
{
int err, err2;
+ struct map *alm = NULL;
+
+ if (al && al->map)
+ alm = map__get(al->map);
err = sample__resolve_callchain(iter->sample, &callchain_cursor, &iter->parent,
iter->evsel, al, max_stack_depth);
@@ -1058,6 +1063,8 @@ out:
if (!err)
err = err2;
+ map__put(alm);
+
return err;
}