Quoting Jishnu Prakash (2022-12-20 21:37:12) > When removing a SPMI driver, there can be a crash due to NULL pointer > dereference if it does not have a remove callback defined. This is > one such call trace observed when removing the QCOM SPMI PMIC driver: > > dump_backtrace.cfi_jt+0x0/0x8 > dump_stack_lvl+0xd8/0x16c > panic+0x188/0x498 > __cfi_slowpath+0x0/0x214 > __cfi_slowpath+0x1dc/0x214 > spmi_drv_remove+0x16c/0x1e0 > device_release_driver_internal+0x468/0x79c > driver_detach+0x11c/0x1a0 > bus_remove_driver+0xc4/0x124 > driver_unregister+0x58/0x84 > cleanup_module+0x1c/0xc24 [qcom_spmi_pmic] > __do_sys_delete_module+0x3ec/0x53c > __arm64_sys_delete_module+0x18/0x28 > el0_svc_common+0xdc/0x294 > el0_svc+0x38/0x9c > el0_sync_handler+0x8c/0xf0 > el0_sync+0x1b4/0x1c0 > > If a driver has all its resources allocated through devm_() APIs and > does not need any other explicit cleanup, it would not require a > remove callback to be defined. Hence, add a check for remove callback > presence before calling it when removing a SPMI driver. > > Signed-off-by: Jishnu Prakash <quic_jprakash@xxxxxxxxxxx> > --- Applied to spmi-next
