* [PATCH v3] bus: mhi: core: Check state before processing power_down
@ 2021-03-10 20:49 Jeffrey Hugo
2021-03-16 6:16 ` Manivannan Sadhasivam
` (2 more replies)
0 siblings, 3 replies; 4+ messages in thread
From: Jeffrey Hugo @ 2021-03-10 20:49 UTC (permalink / raw)
To: manivannan.sadhasivam, hemantk
Cc: bbhatt, linux-arm-msm, linux-kernel, Jeffrey Hugo
We cannot process a power_down if the power state is DISABLED. There is
no valid mhi_ctxt in that case, so attepting to process the power_down
will likely result in a null pointer dereference. If the power state is
DISABLED, there is nothing to do anyways, so just bail early.
Signed-off-by: Jeffrey Hugo <jhugo@codeaurora.org>
---
v3: Move the pm_lock use up
v2: Fix subject and tweak the locking to avoid needless lock/unlock/relock
drivers/bus/mhi/core/pm.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)
diff --git a/drivers/bus/mhi/core/pm.c b/drivers/bus/mhi/core/pm.c
index 414da4f..ea62549 100644
--- a/drivers/bus/mhi/core/pm.c
+++ b/drivers/bus/mhi/core/pm.c
@@ -1149,6 +1149,7 @@ int mhi_async_power_up(struct mhi_controller *mhi_cntrl)
mhi_deinit_dev_ctxt(mhi_cntrl);
error_dev_ctxt:
+ mhi_cntrl->pm_state = MHI_PM_DISABLE;
mutex_unlock(&mhi_cntrl->pm_mutex);
return ret;
@@ -1160,12 +1161,19 @@ void mhi_power_down(struct mhi_controller *mhi_cntrl, bool graceful)
enum mhi_pm_state cur_state, transition_state;
struct device *dev = &mhi_cntrl->mhi_dev->dev;
+ mutex_lock(&mhi_cntrl->pm_mutex);
+ write_lock_irq(&mhi_cntrl->pm_lock);
+ cur_state = mhi_cntrl->pm_state;
+ if (cur_state == MHI_PM_DISABLE) {
+ write_unlock_irq(&mhi_cntrl->pm_lock);
+ mutex_unlock(&mhi_cntrl->pm_mutex);
+ return; /* Already powered down */
+ }
+
/* If it's not a graceful shutdown, force MHI to linkdown state */
transition_state = (graceful) ? MHI_PM_SHUTDOWN_PROCESS :
MHI_PM_LD_ERR_FATAL_DETECT;
- mutex_lock(&mhi_cntrl->pm_mutex);
- write_lock_irq(&mhi_cntrl->pm_lock);
cur_state = mhi_tryset_pm_state(mhi_cntrl, transition_state);
if (cur_state != transition_state) {
dev_err(dev, "Failed to move to state: %s from: %s\n",
--
Qualcomm Technologies, Inc. is a member of the
Code Aurora Forum, a Linux Foundation Collaborative Project.
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH v3] bus: mhi: core: Check state before processing power_down
2021-03-10 20:49 [PATCH v3] bus: mhi: core: Check state before processing power_down Jeffrey Hugo
@ 2021-03-16 6:16 ` Manivannan Sadhasivam
2021-03-16 6:18 ` Manivannan Sadhasivam
2021-05-26 19:03 ` patchwork-bot+linux-arm-msm
2 siblings, 0 replies; 4+ messages in thread
From: Manivannan Sadhasivam @ 2021-03-16 6:16 UTC (permalink / raw)
To: Jeffrey Hugo; +Cc: hemantk, bbhatt, linux-arm-msm, linux-kernel
On Wed, Mar 10, 2021 at 01:49:25PM -0700, Jeffrey Hugo wrote:
> We cannot process a power_down if the power state is DISABLED. There is
> no valid mhi_ctxt in that case, so attepting to process the power_down
> will likely result in a null pointer dereference. If the power state is
> DISABLED, there is nothing to do anyways, so just bail early.
>
> Signed-off-by: Jeffrey Hugo <jhugo@codeaurora.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Thanks,
Mani
> ---
>
> v3: Move the pm_lock use up
> v2: Fix subject and tweak the locking to avoid needless lock/unlock/relock
>
> drivers/bus/mhi/core/pm.c | 12 ++++++++++--
> 1 file changed, 10 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/bus/mhi/core/pm.c b/drivers/bus/mhi/core/pm.c
> index 414da4f..ea62549 100644
> --- a/drivers/bus/mhi/core/pm.c
> +++ b/drivers/bus/mhi/core/pm.c
> @@ -1149,6 +1149,7 @@ int mhi_async_power_up(struct mhi_controller *mhi_cntrl)
> mhi_deinit_dev_ctxt(mhi_cntrl);
>
> error_dev_ctxt:
> + mhi_cntrl->pm_state = MHI_PM_DISABLE;
> mutex_unlock(&mhi_cntrl->pm_mutex);
>
> return ret;
> @@ -1160,12 +1161,19 @@ void mhi_power_down(struct mhi_controller *mhi_cntrl, bool graceful)
> enum mhi_pm_state cur_state, transition_state;
> struct device *dev = &mhi_cntrl->mhi_dev->dev;
>
> + mutex_lock(&mhi_cntrl->pm_mutex);
> + write_lock_irq(&mhi_cntrl->pm_lock);
> + cur_state = mhi_cntrl->pm_state;
> + if (cur_state == MHI_PM_DISABLE) {
> + write_unlock_irq(&mhi_cntrl->pm_lock);
> + mutex_unlock(&mhi_cntrl->pm_mutex);
> + return; /* Already powered down */
> + }
> +
> /* If it's not a graceful shutdown, force MHI to linkdown state */
> transition_state = (graceful) ? MHI_PM_SHUTDOWN_PROCESS :
> MHI_PM_LD_ERR_FATAL_DETECT;
>
> - mutex_lock(&mhi_cntrl->pm_mutex);
> - write_lock_irq(&mhi_cntrl->pm_lock);
> cur_state = mhi_tryset_pm_state(mhi_cntrl, transition_state);
> if (cur_state != transition_state) {
> dev_err(dev, "Failed to move to state: %s from: %s\n",
> --
> Qualcomm Technologies, Inc. is a member of the
> Code Aurora Forum, a Linux Foundation Collaborative Project.
>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH v3] bus: mhi: core: Check state before processing power_down
2021-03-10 20:49 [PATCH v3] bus: mhi: core: Check state before processing power_down Jeffrey Hugo
2021-03-16 6:16 ` Manivannan Sadhasivam
@ 2021-03-16 6:18 ` Manivannan Sadhasivam
2021-05-26 19:03 ` patchwork-bot+linux-arm-msm
2 siblings, 0 replies; 4+ messages in thread
From: Manivannan Sadhasivam @ 2021-03-16 6:18 UTC (permalink / raw)
To: Jeffrey Hugo; +Cc: hemantk, bbhatt, linux-arm-msm, linux-kernel
On Wed, Mar 10, 2021 at 01:49:25PM -0700, Jeffrey Hugo wrote:
> We cannot process a power_down if the power state is DISABLED. There is
> no valid mhi_ctxt in that case, so attepting to process the power_down
> will likely result in a null pointer dereference. If the power state is
> DISABLED, there is nothing to do anyways, so just bail early.
>
> Signed-off-by: Jeffrey Hugo <jhugo@codeaurora.org>
Applied to mhi-next!
Thanks,
Mani
> ---
>
> v3: Move the pm_lock use up
> v2: Fix subject and tweak the locking to avoid needless lock/unlock/relock
>
> drivers/bus/mhi/core/pm.c | 12 ++++++++++--
> 1 file changed, 10 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/bus/mhi/core/pm.c b/drivers/bus/mhi/core/pm.c
> index 414da4f..ea62549 100644
> --- a/drivers/bus/mhi/core/pm.c
> +++ b/drivers/bus/mhi/core/pm.c
> @@ -1149,6 +1149,7 @@ int mhi_async_power_up(struct mhi_controller *mhi_cntrl)
> mhi_deinit_dev_ctxt(mhi_cntrl);
>
> error_dev_ctxt:
> + mhi_cntrl->pm_state = MHI_PM_DISABLE;
> mutex_unlock(&mhi_cntrl->pm_mutex);
>
> return ret;
> @@ -1160,12 +1161,19 @@ void mhi_power_down(struct mhi_controller *mhi_cntrl, bool graceful)
> enum mhi_pm_state cur_state, transition_state;
> struct device *dev = &mhi_cntrl->mhi_dev->dev;
>
> + mutex_lock(&mhi_cntrl->pm_mutex);
> + write_lock_irq(&mhi_cntrl->pm_lock);
> + cur_state = mhi_cntrl->pm_state;
> + if (cur_state == MHI_PM_DISABLE) {
> + write_unlock_irq(&mhi_cntrl->pm_lock);
> + mutex_unlock(&mhi_cntrl->pm_mutex);
> + return; /* Already powered down */
> + }
> +
> /* If it's not a graceful shutdown, force MHI to linkdown state */
> transition_state = (graceful) ? MHI_PM_SHUTDOWN_PROCESS :
> MHI_PM_LD_ERR_FATAL_DETECT;
>
> - mutex_lock(&mhi_cntrl->pm_mutex);
> - write_lock_irq(&mhi_cntrl->pm_lock);
> cur_state = mhi_tryset_pm_state(mhi_cntrl, transition_state);
> if (cur_state != transition_state) {
> dev_err(dev, "Failed to move to state: %s from: %s\n",
> --
> Qualcomm Technologies, Inc. is a member of the
> Code Aurora Forum, a Linux Foundation Collaborative Project.
>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH v3] bus: mhi: core: Check state before processing power_down
2021-03-10 20:49 [PATCH v3] bus: mhi: core: Check state before processing power_down Jeffrey Hugo
2021-03-16 6:16 ` Manivannan Sadhasivam
2021-03-16 6:18 ` Manivannan Sadhasivam
@ 2021-05-26 19:03 ` patchwork-bot+linux-arm-msm
2 siblings, 0 replies; 4+ messages in thread
From: patchwork-bot+linux-arm-msm @ 2021-05-26 19:03 UTC (permalink / raw)
To: Jeffrey Hugo; +Cc: linux-arm-msm
Hello:
This patch was applied to qcom/linux.git (refs/heads/for-next):
On Wed, 10 Mar 2021 13:49:25 -0700 you wrote:
> We cannot process a power_down if the power state is DISABLED. There is
> no valid mhi_ctxt in that case, so attepting to process the power_down
> will likely result in a null pointer dereference. If the power state is
> DISABLED, there is nothing to do anyways, so just bail early.
>
> Signed-off-by: Jeffrey Hugo <jhugo@codeaurora.org>
>
> [...]
Here is the summary with links:
- [v3] bus: mhi: core: Check state before processing power_down
https://git.kernel.org/qcom/c/9e40641f62cd
You are awesome, thank you!
--
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html
^ permalink raw reply [flat|nested] 4+ messages in thread
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2021-03-10 20:49 [PATCH v3] bus: mhi: core: Check state before processing power_down Jeffrey Hugo
2021-03-16 6:16 ` Manivannan Sadhasivam
2021-03-16 6:18 ` Manivannan Sadhasivam
2021-05-26 19:03 ` patchwork-bot+linux-arm-msm
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