On Tue, 04 Jan 2022, 赵军奎 <[email protected]> wrote: > -----邮件原件----- > 发件人: [email protected] <[email protected]> 代表 Jani Nikula > 发送时间: 2021年12月31日 19:09 > 收件人: 赵军奎 <[email protected]>; Maarten Lankhorst > <[email protected]>; Maxime Ripard <[email protected]>; > Thomas Zimmermann <[email protected]>; David Airlie <[email protected]>; > Daniel Vetter <[email protected]>; [email protected]; > [email protected] > 抄送: 赵军奎 <[email protected]> > 主题: Re: [PATCH] gpu/drm: fix potential memleak in error branch > > On Tue, 16 Nov 2021, Bernard Zhao <[email protected]> wrote: >> This patch try to fix potential memleak in error branch. > >>Please elaborate. > > Hi Jani: > > This patch try to fix potential memleak in error branch. > For example: > nv50_sor_create ->nv50_mstm_new-> drm_dp_mst_topology_mgr_init > In function drm_dp_mst_topology_mgr_init, there are five error branches, > error branch just return error code, no free called. > And we see that the caller didn`t do the drm_dp_mst_topology_mgr_destroy job. > I am not sure if there some gap, I think this may bring in the risk of > memleak issue. > Thanks!
This should be part of the commit message. > > BR//Bernard > >>BR, >>Jani. > > >> >> Signed-off-by: Bernard Zhao <[email protected]> >> --- >> drivers/gpu/drm/drm_dp_mst_topology.c | 22 ++++++++++++++++------ >> 1 file changed, 16 insertions(+), 6 deletions(-) >> >> diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c >> b/drivers/gpu/drm/drm_dp_mst_topology.c >> index f3d79eda94bb..f73b180dee73 100644 >> --- a/drivers/gpu/drm/drm_dp_mst_topology.c >> +++ b/drivers/gpu/drm/drm_dp_mst_topology.c >> @@ -5501,7 +5501,10 @@ int drm_dp_mst_topology_mgr_init(struct >> drm_dp_mst_topology_mgr *mgr, >> int max_lane_count, int max_link_rate, >> int conn_base_id) >> { >> - struct drm_dp_mst_topology_state *mst_state; >> + struct drm_dp_mst_topology_state *mst_state = NULL; This is superfluous. Other than that, Reviewed-by: Jani Nikula <[email protected]> >> + >> + mgr->payloads = NULL; >> + mgr->proposed_vcpis = NULL; >> >> mutex_init(&mgr->lock); >> mutex_init(&mgr->qlock); >> @@ -5523,7 +5526,7 @@ int drm_dp_mst_topology_mgr_init(struct >> drm_dp_mst_topology_mgr *mgr, >> */ >> mgr->delayed_destroy_wq = alloc_ordered_workqueue("drm_dp_mst_wq", 0); >> if (mgr->delayed_destroy_wq == NULL) >> - return -ENOMEM; >> + goto out; >> >> INIT_WORK(&mgr->work, drm_dp_mst_link_probe_work); >> INIT_WORK(&mgr->tx_work, drm_dp_tx_work); @@ -5539,18 +5542,18 @@ >> int drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr *mgr, >> mgr->conn_base_id = conn_base_id; >> if (max_payloads + 1 > sizeof(mgr->payload_mask) * 8 || >> max_payloads + 1 > sizeof(mgr->vcpi_mask) * 8) >> - return -EINVAL; >> + goto failed; >> mgr->payloads = kcalloc(max_payloads, sizeof(struct drm_dp_payload), >> GFP_KERNEL); >> if (!mgr->payloads) >> - return -ENOMEM; >> + goto failed; >> mgr->proposed_vcpis = kcalloc(max_payloads, sizeof(struct drm_dp_vcpi >> *), GFP_KERNEL); >> if (!mgr->proposed_vcpis) >> - return -ENOMEM; >> + goto failed; >> set_bit(0, &mgr->payload_mask); >> >> mst_state = kzalloc(sizeof(*mst_state), GFP_KERNEL); >> if (mst_state == NULL) >> - return -ENOMEM; >> + goto failed; >> >> mst_state->total_avail_slots = 63; >> mst_state->start_slot = 1; >> @@ -5563,6 +5566,13 @@ int drm_dp_mst_topology_mgr_init(struct >> drm_dp_mst_topology_mgr *mgr, >> &drm_dp_mst_topology_state_funcs); >> >> return 0; >> + >> +failed: >> + kfree(mgr->proposed_vcpis); >> + kfree(mgr->payloads); >> + destroy_workqueue(mgr->delayed_destroy_wq); >> +out: >> + return -ENOMEM; >> } >> EXPORT_SYMBOL(drm_dp_mst_topology_mgr_init); > > -- > Jani Nikula, Intel Open Source Graphics Center -- Jani Nikula, Intel Open Source Graphics Center
