[PATCH v2 18/26] perf machine: Fix leak of kernel dso

[Ian Rogers]

The kernel dso may be found by searching dsos or allocating if not
found. The allocation returns with a reference count of 2, once for
the dsos list and once for the returned value. The list search has a
reference count of 1, once for the dsos list. To make the reference
counts consistent, increase the dsos list search reference count to 2
with a dso__get, and do a put when the scope ends for either the
allocated or found dso.

This issue was found with leak sanitizer and reference count checking.

Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
---
 tools/perf/util/machine.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
index 46af5e9748c9..f8e6c07f0048 100644
--- a/tools/perf/util/machine.c
+++ b/tools/perf/util/machine.c
@@ -1868,7 +1868,7 @@ static int machine__process_kernel_mmap_event(struct machine *machine,
 				continue;
 
 
-			kernel = dso;
+			kernel = dso__get(dso);
 			break;
 		}
 
@@ -1913,6 +1913,7 @@ static int machine__process_kernel_mmap_event(struct machine *machine,
 			 */
 			dso__load(kernel, machine__kernel_map(machine));
 		}
+		dso__put(kernel);
 	} else if (perf_event__is_extra_kernel_mmap(machine, xm)) {
 		return machine__process_extra_kernel_map(machine, xm);
 	}
-- 
2.41.0.162.gfafddb0af9-goog