On 17/08/2023 15:31, James Clark wrote:
On 17/08/2023 09:59, Junhao He wrote:
There are memory leaks reported by kmemleak: ... unreferenced object 0xffff2020103c3200 (size 256): comm "insmod", pid 4476, jiffies 4294978252 (age 50072.536s) hex dump (first 32 bytes): 10 60 40 06 28 20 ff ff 10 c0 59 06 20 20 ff ff .`@.( ....Y. .. 10 e0 47 06 28 20 ff ff 10 00 49 06 28 20 ff ff ..G.( ....I.( .. backtrace: [<0000000034ec4724>] __kmem_cache_alloc_node+0x2f8/0x348 [<0000000057fbc15d>] __kmalloc_node_track_caller+0x5c/0x110 [<00000055d5e34b>] krealloc+0x8c/0x178 [<00000000a4635beb>] coresight_alloc_device_name+0x128/0x188 [coresight] [<00000000a92ddfee>] funnel_cs_ops+0x10/0xfffffffffffedaa0 [coresight_funnel] [<00000000449e20f8>] dynamic_funnel_ids+0x80/0xfffffffffffed840 [coresight_funnel] ...
when remove driver, the golab variables defined by the macro DEFINE_CORESIGHT_DEVLIST will be released, dict->nr_idx and dict->fwnode_list are cleared to 0. The lifetime of the golab variable has ended. So the buffer pointer is lost.
Use the callback of devm_add_action_or_reset() to free memory.
Fixes: 0f5f9b6ba9e1 ("coresight: Use platform agnostic names") Signed-off-by: Junhao He hejunhao3@huawei.com
drivers/hwtracing/coresight/coresight-core.c | 20 +++++++++++++++++++- 1 file changed, 19 insertions(+), 1 deletion(-)
diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c index 9fabe00a40d6..6849faad697d 100644 --- a/drivers/hwtracing/coresight/coresight-core.c +++ b/drivers/hwtracing/coresight/coresight-core.c @@ -1756,6 +1756,20 @@ bool coresight_loses_context_with_cpu(struct device *dev) } EXPORT_SYMBOL_GPL(coresight_loses_context_with_cpu); +void coresight_release_dev_list(void *data) +{
- struct coresight_dev_list *dict = data;
- mutex_lock(&coresight_mutex);
- if (dict->nr_idx) {
kfree(dict->fwnode_list);dict->nr_idx = 0;- }
- mutex_unlock(&coresight_mutex);
+}
- /*
- coresight_alloc_device_name - Get an index for a given device in the
- device index list specific to a driver. An index is allocated for a
@@ -1766,12 +1780,16 @@ EXPORT_SYMBOL_GPL(coresight_loses_context_with_cpu); char *coresight_alloc_device_name(struct coresight_dev_list *dict, struct device *dev) {
- int idx;
- int idx, ret; char *name = NULL; struct fwnode_handle **list;
mutex_lock(&coresight_mutex);
- ret = devm_add_action_or_reset(dev, coresight_release_dev_list, dict);
- if (ret)
goto done;Hi Junhao,
Changing the list allocator to a devm one fixes the issue without having to add the callback:
list = krealloc_array(dict->fwnode_list,
list = devm_krealloc_array(dev, dict->fwnode_list,
Thats problematic. Please note that the list is "per module/driver" not per device. So, you cannot tie it to a single device. Please see my response in the thread.
Suzuki
The callback stands out a bit and would make someone reading it wonder why only that one is done that way but all other allocations in Coresight avoid it.
The nr_idx variable doesn't need to be zeroed because its backed by a static variable and is zeroed when the module is reloaded as far as I can see.
Thanks James
idx = coresight_search_device_idx(dict, dev_fwnode(dev)); if (idx < 0) { /* Make space for the new entry */