2015-12-07 08:51:44

by Wang Nan

[permalink] [raw]
Subject: [PATCH] perf tools: Clear struct machine during machine__init()

There are so many test cases use stack allocated 'struct machine'.
Including:
test__hists_link
test__hists_filter
test__mmap_thread_lookup
test__thread_mg_share
test__hists_output
test__hists_cumulate

Also, in non-test code (for example, machine__new_host()) there are
code use 'malloc()' to alloc struct machine.

These are dangerous operations, cause some tests fail or hung in
machines__exit(). For example, in

machines__exit ->
machine__destroy_kernel_maps ->
map_groups__remove ->
maps__remove ->
pthread_rwlock_wrlock

a incorrectly initialized lock causes unintended behavior.

This patch bzero() that structure in machine__init() to ensure all
fields in 'struct machine' are initialized to zero.

Signed-off-by: Wang Nan <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Namhyung Kim <[email protected]>
---
tools/perf/util/machine.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
index bfc289c..188cfdf 100644
--- a/tools/perf/util/machine.c
+++ b/tools/perf/util/machine.c
@@ -25,6 +25,7 @@ static void dsos__init(struct dsos *dsos)

int machine__init(struct machine *machine, const char *root_dir, pid_t pid)
{
+ bzero(machine, sizeof(*machine));
map_groups__init(&machine->kmaps, machine);
RB_CLEAR_NODE(&machine->rb_node);
dsos__init(&machine->dsos);
--
1.8.3.4