| Message ID | 20221104064512.8569-1-yuancan@huawei.com (mailing list archive) |
|---|---|
| State | Handled Elsewhere |
| Headers | show |
| Series | [v2] drm/ingenic: Fix missing platform_driver_unregister() call in ingenic_drm_init() | expand |
Hi, Le ven. 4 nov. 2022 à 06:45:12 +0000, Yuan Can <yuancan@huawei.com> a écrit : > A problem about modprobe ingenic-drm failed is triggered with the > following > log given: > > [ 303.561088] Error: Driver 'ingenic-ipu' is already registered, > aborting... > modprobe: ERROR: could not insert 'ingenic_drm': Device or resource > busy > > The reason is that ingenic_drm_init() returns > platform_driver_register() > directly without checking its return value, if > platform_driver_register() > failed, it returns without unregistering ingenic_ipu_driver_ptr, > resulting > the ingenic-drm can never be installed later. > A simple call graph is shown as below: > > ingenic_drm_init() > platform_driver_register() # ingenic_ipu_driver_ptr are registered > platform_driver_register() > driver_register() > bus_add_driver() > priv = kzalloc(...) # OOM happened > # return without unregister ingenic_ipu_driver_ptr > > Fixing this problem by checking the return value of > platform_driver_register() and do platform_unregister_drivers() if > error happened. > > Fixes: fc1acf317b01 ("drm/ingenic: Add support for the IPU") > Signed-off-by: Yuan Can <yuancan@huawei.com> > Cc: stable@vger.kernel.org Applied, thanks! Cheers, -Paul > --- > Changes in v2: > - Add missing Cc: stable@vger.kernel.org > > drivers/gpu/drm/ingenic/ingenic-drm-drv.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/ingenic/ingenic-drm-drv.c > b/drivers/gpu/drm/ingenic/ingenic-drm-drv.c > index ab0515d2c420..4499a04f7c13 100644 > --- a/drivers/gpu/drm/ingenic/ingenic-drm-drv.c > +++ b/drivers/gpu/drm/ingenic/ingenic-drm-drv.c > @@ -1629,7 +1629,11 @@ static int ingenic_drm_init(void) > return err; > } > > - return platform_driver_register(&ingenic_drm_driver); > + err = platform_driver_register(&ingenic_drm_driver); > + if (IS_ENABLED(CONFIG_DRM_INGENIC_IPU) && err) > + platform_driver_unregister(ingenic_ipu_driver_ptr); > + > + return err; > } > module_init(ingenic_drm_init); > > -- > 2.17.1 >
diff --git a/drivers/gpu/drm/ingenic/ingenic-drm-drv.c b/drivers/gpu/drm/ingenic/ingenic-drm-drv.c index ab0515d2c420..4499a04f7c13 100644 --- a/drivers/gpu/drm/ingenic/ingenic-drm-drv.c +++ b/drivers/gpu/drm/ingenic/ingenic-drm-drv.c @@ -1629,7 +1629,11 @@ static int ingenic_drm_init(void) return err; } - return platform_driver_register(&ingenic_drm_driver); + err = platform_driver_register(&ingenic_drm_driver); + if (IS_ENABLED(CONFIG_DRM_INGENIC_IPU) && err) + platform_driver_unregister(ingenic_ipu_driver_ptr); + + return err; } module_init(ingenic_drm_init);
A problem about modprobe ingenic-drm failed is triggered with the following log given: [ 303.561088] Error: Driver 'ingenic-ipu' is already registered, aborting... modprobe: ERROR: could not insert 'ingenic_drm': Device or resource busy The reason is that ingenic_drm_init() returns platform_driver_register() directly without checking its return value, if platform_driver_register() failed, it returns without unregistering ingenic_ipu_driver_ptr, resulting the ingenic-drm can never be installed later. A simple call graph is shown as below: ingenic_drm_init() platform_driver_register() # ingenic_ipu_driver_ptr are registered platform_driver_register() driver_register() bus_add_driver() priv = kzalloc(...) # OOM happened # return without unregister ingenic_ipu_driver_ptr Fixing this problem by checking the return value of platform_driver_register() and do platform_unregister_drivers() if error happened. Fixes: fc1acf317b01 ("drm/ingenic: Add support for the IPU") Signed-off-by: Yuan Can <yuancan@huawei.com> Cc: stable@vger.kernel.org --- Changes in v2: - Add missing Cc: stable@vger.kernel.org drivers/gpu/drm/ingenic/ingenic-drm-drv.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)