From: Shixiong Ou <oushixi...@kylinos.cn>
[WHY]
If Calling hibmc_mm_init() failed in hibmc_load(), the hibmc_unload()
will access a NULL pointer, as it don't call ww_mutex_init() to
initialize mode_config.connection_mutex but try to lock it when
calling drm_atomic_helper_shutdown().
[ 50.939211][ 0] Unable to handle kernel NULL pointer dereference at virtual
address 0000000000000018
......
[ 51.149882][ 0] Call trace:
[ 51.152750][ 0] ww_mutex_lock+0xf0/0x1e0
[ 51.156829][ 0] drm_modeset_lock+0x184/0x2c0
[ 51.161254][ 0] drm_modeset_lock_all_ctx+0x98/0x188
[ 51.166284][ 0] drm_atomic_helper_shutdown+0xa4/0x128
[ 51.171487][ 0] hibmc_unload+0x50/0x2f0
[ 51.175479][ 0] hibmc_load+0x5d8/0x888
[ 51.179386][ 0] drm_dev_register+0x280/0x558
[ 51.183811][ 0] drm_get_pci_dev+0x140/0x3c8
[ 51.188150][ 0] hibmc_pci_probe+0x148/0x190
[ 51.192489][ 0] local_pci_probe+0xc4/0x180
[ 51.196742][ 0] pci_device_probe+0x328/0x530
[ 51.201167][ 0] really_probe+0x498/0x9a0
[ 51.205248][ 0] driver_probe_device+0x224/0x308
[ 51.209932][ 0] device_driver_attach+0xec/0x128
[ 51.214616][ 0] __driver_attach+0x144/0x280
[ 51.218955][ 0] bus_for_each_dev+0x120/0x1a0
[ 51.223380][ 0] driver_attach+0x48/0x60
[ 51.227372][ 0] bus_add_driver+0x328/0x578
[ 51.231625][ 0] driver_register+0x148/0x398
[ 51.235965][ 0] __pci_register_driver+0x15c/0x1c8
[ 51.240823][ 0] hibmc_init+0x2c/0x34
[ 51.244557][ 0] do_one_initcall+0xc8/0x4a8
[ 51.248810][ 0] kernel_init_freeable+0x678/0x75c
[ 51.253582][ 0] kernel_init+0x18/0x128
[ 51.257489][ 0] ret_from_fork+0x10/0x18
[HOW]
Do not call drm_atomic_helper_shutdown() if drmm_mode_config_init() failed.
Signed-off-by: Shixiong Ou <oushixi...@kylinos.cn>
---
drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c | 13 +++++++------
1 file changed, 7 insertions(+), 6 deletions(-)
diff --git a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c
b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c
index 768b97f9e74a..8edc83db2afb 100644
--- a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c
+++ b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c
@@ -323,29 +323,29 @@ static int hibmc_load(struct drm_device *dev)
ret = hibmc_hw_init(priv);
if (ret)
- goto err;
+ goto err_return;
ret = drmm_vram_helper_init(dev, pci_resource_start(pdev, 0),
pci_resource_len(pdev, 0));
if (ret) {
drm_err(dev, "Error initializing VRAM MM; %d\n", ret);
- goto err;
+ goto err_return;
}
ret = hibmc_kms_init(priv);
if (ret)
- goto err;
+ goto err_return;
ret = drm_vblank_init(dev, dev->mode_config.num_crtc);
if (ret) {
drm_err(dev, "failed to initialize vblank: %d\n", ret);
- goto err;
+ goto err_unload;
}
ret = hibmc_msi_init(dev);
if (ret) {
drm_err(dev, "hibmc msi init failed, ret:%d\n", ret);
- goto err;
+ goto err_unload;
}
/* reset all the states of crtc/plane/encoder/connector */
@@ -353,8 +353,9 @@ static int hibmc_load(struct drm_device *dev)
return 0;
-err:
+err_unload:
hibmc_unload(dev);
+err_return:
drm_err(dev, "failed to initialize drm driver: %d\n", ret);
return ret;
}
--
2.17.1
