| Message ID | 20220715080721.1477324-1-botton_zhang@163.com (mailing list archive) |
|---|---|
| State | Rejected |
| Headers | show |
| Series | [v1,1/1] kfd: fixed memleak about release topology | expand |
Am 2022-07-15 um 04:07 schrieb ZhiJie.zhang: > memleak will happend that reload module due to ignore kfree when release topology > > Signed-off-by: ZhiJie.zhang <botton_zhang@163.com> > --- > drivers/gpu/drm/amd/amdkfd/kfd_topology.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_topology.c b/drivers/gpu/drm/amd/amdkfd/kfd_topology.c > index 8d50d207cf66..8b86f56bd50c 100644 > --- a/drivers/gpu/drm/amd/amdkfd/kfd_topology.c > +++ b/drivers/gpu/drm/amd/amdkfd/kfd_topology.c > @@ -872,6 +872,7 @@ static void kfd_topology_release_sysfs(void) > } > kobject_del(sys_props.kobj_topology); > kobject_put(sys_props.kobj_topology); > + kfree(sys_props.kobj_topology); Sorry for the late response. This looks incorrect. kobjects are reference counted. The underlying memory should be freed by a callback when the reference count reaches 0 in kobject_put. Freeing the object here explicitly would lead to a double-free. The callback in this case is kfd_topology_kobj_release, which calls kfree. Am I missing anything? Regards, Felix > sys_props.kobj_topology = NULL; > } > }
在 2022/8/18 6:31, Felix Kuehling 写道: > Am 2022-07-15 um 04:07 schrieb ZhiJie.zhang: >> memleak will happend that reload module due to ignore kfree when >> release topology >> >> Signed-off-by: ZhiJie.zhang <botton_zhang@163.com> >> --- >> drivers/gpu/drm/amd/amdkfd/kfd_topology.c | 1 + >> 1 file changed, 1 insertion(+) >> >> diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_topology.c >> b/drivers/gpu/drm/amd/amdkfd/kfd_topology.c >> index 8d50d207cf66..8b86f56bd50c 100644 >> --- a/drivers/gpu/drm/amd/amdkfd/kfd_topology.c >> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_topology.c >> @@ -872,6 +872,7 @@ static void kfd_topology_release_sysfs(void) >> } >> kobject_del(sys_props.kobj_topology); >> kobject_put(sys_props.kobj_topology); >> + kfree(sys_props.kobj_topology); > > Sorry for the late response. This looks incorrect. kobjects are > reference counted. The underlying memory should be freed by a callback > when the reference count reaches 0 in kobject_put. Freeing the object > here explicitly would lead to a double-free. > > The callback in this case is kfd_topology_kobj_release, which calls > kfree. Am I missing anything? > Yes, Your are right, this is my misstake, please ignore this patch > Regards, > Felix > > >> sys_props.kobj_topology = NULL; >> } >> } Regards. Zhijie
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_topology.c b/drivers/gpu/drm/amd/amdkfd/kfd_topology.c index 8d50d207cf66..8b86f56bd50c 100644 --- a/drivers/gpu/drm/amd/amdkfd/kfd_topology.c +++ b/drivers/gpu/drm/amd/amdkfd/kfd_topology.c @@ -872,6 +872,7 @@ static void kfd_topology_release_sysfs(void) } kobject_del(sys_props.kobj_topology); kobject_put(sys_props.kobj_topology); + kfree(sys_props.kobj_topology); sys_props.kobj_topology = NULL; } }
memleak will happend that reload module due to ignore kfree when release topology Signed-off-by: ZhiJie.zhang <botton_zhang@163.com> --- drivers/gpu/drm/amd/amdkfd/kfd_topology.c | 1 + 1 file changed, 1 insertion(+)