From 3c1bd0047124f506294520341cfe03e19ea773e3 Mon Sep 17 00:00:00 2001 From: Hemant Kumar Date: Thu, 21 May 2020 22:32:45 +0530 Subject: [PATCH] bus: mhi: core: Handle disable transitions in state worker Mission mode transition is handled by state worker thread but power off is not. There is a possibility while mission mode transition is in progress which calls MHI client driver probe, power off is issued by MHI controller. This results into client driver probe and remove running in parallel and causes use after free situation. By queuing disable transition work when mission mode is in progress prevents the race condition. Signed-off-by: Hemant Kumar Reviewed-by: Jeffrey Hugo Reviewed-by: Manivannan Sadhasivam Signed-off-by: Manivannan Sadhasivam Link: https://lore.kernel.org/r/20200521170249.21795-11-manivannan.sadhasivam@linaro.org Signed-off-by: Greg Kroah-Hartman --- drivers/bus/mhi/core/init.c | 1 + drivers/bus/mhi/core/internal.h | 1 + drivers/bus/mhi/core/pm.c | 11 ++++++++++- 3 files changed, 12 insertions(+), 1 deletion(-) diff --git a/drivers/bus/mhi/core/init.c b/drivers/bus/mhi/core/init.c index 3a853c5..12207cc 100644 --- a/drivers/bus/mhi/core/init.c +++ b/drivers/bus/mhi/core/init.c @@ -35,6 +35,7 @@ const char * const dev_state_tran_str[DEV_ST_TRANSITION_MAX] = { [DEV_ST_TRANSITION_SBL] = "SBL", [DEV_ST_TRANSITION_MISSION_MODE] = "MISSION_MODE", [DEV_ST_TRANSITION_SYS_ERR] = "SYS_ERR", + [DEV_ST_TRANSITION_DISABLE] = "DISABLE", }; const char * const mhi_state_str[MHI_STATE_MAX] = { diff --git a/drivers/bus/mhi/core/internal.h b/drivers/bus/mhi/core/internal.h index f01283b..b1f640b 100644 --- a/drivers/bus/mhi/core/internal.h +++ b/drivers/bus/mhi/core/internal.h @@ -387,6 +387,7 @@ enum dev_st_transition { DEV_ST_TRANSITION_SBL, DEV_ST_TRANSITION_MISSION_MODE, DEV_ST_TRANSITION_SYS_ERR, + DEV_ST_TRANSITION_DISABLE, DEV_ST_TRANSITION_MAX, }; diff --git a/drivers/bus/mhi/core/pm.c b/drivers/bus/mhi/core/pm.c index d9964d4..345f197 100644 --- a/drivers/bus/mhi/core/pm.c +++ b/drivers/bus/mhi/core/pm.c @@ -657,6 +657,10 @@ void mhi_pm_st_worker(struct work_struct *work) mhi_pm_disable_transition (mhi_cntrl, MHI_PM_SYS_ERR_PROCESS); break; + case DEV_ST_TRANSITION_DISABLE: + mhi_pm_disable_transition + (mhi_cntrl, MHI_PM_SHUTDOWN_PROCESS); + break; default: break; } @@ -1011,7 +1015,12 @@ void mhi_power_down(struct mhi_controller *mhi_cntrl, bool graceful) to_mhi_pm_state_str(MHI_PM_LD_ERR_FATAL_DETECT), to_mhi_pm_state_str(mhi_cntrl->pm_state)); } - mhi_pm_disable_transition(mhi_cntrl, MHI_PM_SHUTDOWN_PROCESS); + + mhi_queue_state_transition(mhi_cntrl, DEV_ST_TRANSITION_DISABLE); + + /* Wait for shutdown to complete */ + flush_work(&mhi_cntrl->st_worker); + mhi_deinit_free_irq(mhi_cntrl); if (!mhi_cntrl->pre_init) { -- 2.7.4