diff mbox series

[3/3] remoteproc: pru: Fix and cleanup firmware interrupt mapping logic

Message ID 20210323223839.17464-4-s-anna@ti.com
State New
Headers show
Series [1/3] remoteproc: pru: Fixup interrupt-parent logic for fw events | expand

Commit Message

Suman Anna March 23, 2021, 10:38 p.m. UTC
The PRU firmware interrupt mappings are configured and unconfigured in
.start() and .stop() callbacks respectively using the variables 'evt_count'
and a 'mapped_irq' pointer. These variables are modified only during these
callbacks but are not re-initialized/reset properly during unwind or
failure paths. These stale values caused a kernel crash while stopping a
PRU remoteproc running a different firmware with no events on a subsequent
run after a previous run that was running a firmware with events.

Fix this crash by ensuring that the evt_count is 0 and the mapped_irq
pointer is set to NULL in pru_dispose_irq_mapping(). Also, reset these
variables properly during any failures in the .start() callback. While
at this, the pru_dispose_irq_mapping() callsites are all made to look
the same, moving any conditional logic to inside the function.

Fixes: c75c9fdac66e ("remoteproc: pru: Add support for PRU specific interrupt configuration")
Reported-by: Vignesh Raghavendra <vigneshr@ti.com>
Signed-off-by: Suman Anna <s-anna@ti.com>
---
 drivers/remoteproc/pru_rproc.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

Comments

Mathieu Poirier April 6, 2021, 11:47 p.m. UTC | #1
On Tue, Mar 23, 2021 at 05:38:39PM -0500, Suman Anna wrote:
> The PRU firmware interrupt mappings are configured and unconfigured in

> .start() and .stop() callbacks respectively using the variables 'evt_count'

> and a 'mapped_irq' pointer. These variables are modified only during these

> callbacks but are not re-initialized/reset properly during unwind or

> failure paths. These stale values caused a kernel crash while stopping a

> PRU remoteproc running a different firmware with no events on a subsequent

> run after a previous run that was running a firmware with events.

> 

> Fix this crash by ensuring that the evt_count is 0 and the mapped_irq

> pointer is set to NULL in pru_dispose_irq_mapping(). Also, reset these

> variables properly during any failures in the .start() callback. While

> at this, the pru_dispose_irq_mapping() callsites are all made to look

> the same, moving any conditional logic to inside the function.

> 

> Fixes: c75c9fdac66e ("remoteproc: pru: Add support for PRU specific interrupt configuration")

> Reported-by: Vignesh Raghavendra <vigneshr@ti.com>

> Signed-off-by: Suman Anna <s-anna@ti.com>

> ---

>  drivers/remoteproc/pru_rproc.c | 12 +++++++++---

>  1 file changed, 9 insertions(+), 3 deletions(-)

> 

> diff --git a/drivers/remoteproc/pru_rproc.c b/drivers/remoteproc/pru_rproc.c

> index 87b43976c51b..5df19acb90ed 100644

> --- a/drivers/remoteproc/pru_rproc.c

> +++ b/drivers/remoteproc/pru_rproc.c

> @@ -266,12 +266,17 @@ static void pru_rproc_create_debug_entries(struct rproc *rproc)

>  

>  static void pru_dispose_irq_mapping(struct pru_rproc *pru)

>  {

> -	while (pru->evt_count--) {

> +	if (!pru->mapped_irq)

> +		return;

> +

> +	while (pru->evt_count) {

> +		pru->evt_count--;

>  		if (pru->mapped_irq[pru->evt_count] > 0)

>  			irq_dispose_mapping(pru->mapped_irq[pru->evt_count]);

>  	}

>  

>  	kfree(pru->mapped_irq);

> +	pru->mapped_irq = NULL;

>  }

>  

>  /*

> @@ -324,6 +329,8 @@ static int pru_handle_intrmap(struct rproc *rproc)

>  	of_node_put(parent);

>  	if (!irq_parent) {

>  		kfree(pru->mapped_irq);

> +		pru->mapped_irq = NULL;

> +		pru->evt_count = 0;


Patch 1/3 introduced a check on @parent that doesn't free pru->mapped_irq.  I
would also expect that error path to do the same has what is done here.  And
looking further up I see the error path for !pru->mapped_irq doesn't set
pru->evt_count to zero.

Thanks,
Mathieu

>  		return -ENODEV;

>  	}

>  

> @@ -398,8 +405,7 @@ static int pru_rproc_stop(struct rproc *rproc)

>  	pru_control_write_reg(pru, PRU_CTRL_CTRL, val);

>  

>  	/* dispose irq mapping - new firmware can provide new mapping */

> -	if (pru->mapped_irq)

> -		pru_dispose_irq_mapping(pru);

> +	pru_dispose_irq_mapping(pru);

>  

>  	return 0;

>  }

> -- 

> 2.30.1

>
Suman Anna April 7, 2021, 2:34 p.m. UTC | #2
Hi Mathieu,

On 4/6/21 6:47 PM, Mathieu Poirier wrote:
> On Tue, Mar 23, 2021 at 05:38:39PM -0500, Suman Anna wrote:

>> The PRU firmware interrupt mappings are configured and unconfigured in

>> .start() and .stop() callbacks respectively using the variables 'evt_count'

>> and a 'mapped_irq' pointer. These variables are modified only during these

>> callbacks but are not re-initialized/reset properly during unwind or

>> failure paths. These stale values caused a kernel crash while stopping a

>> PRU remoteproc running a different firmware with no events on a subsequent

>> run after a previous run that was running a firmware with events.

>>

>> Fix this crash by ensuring that the evt_count is 0 and the mapped_irq

>> pointer is set to NULL in pru_dispose_irq_mapping(). Also, reset these

>> variables properly during any failures in the .start() callback. While

>> at this, the pru_dispose_irq_mapping() callsites are all made to look

>> the same, moving any conditional logic to inside the function.

>>

>> Fixes: c75c9fdac66e ("remoteproc: pru: Add support for PRU specific interrupt configuration")

>> Reported-by: Vignesh Raghavendra <vigneshr@ti.com>

>> Signed-off-by: Suman Anna <s-anna@ti.com>

>> ---

>>  drivers/remoteproc/pru_rproc.c | 12 +++++++++---

>>  1 file changed, 9 insertions(+), 3 deletions(-)

>>

>> diff --git a/drivers/remoteproc/pru_rproc.c b/drivers/remoteproc/pru_rproc.c

>> index 87b43976c51b..5df19acb90ed 100644

>> --- a/drivers/remoteproc/pru_rproc.c

>> +++ b/drivers/remoteproc/pru_rproc.c

>> @@ -266,12 +266,17 @@ static void pru_rproc_create_debug_entries(struct rproc *rproc)

>>  

>>  static void pru_dispose_irq_mapping(struct pru_rproc *pru)

>>  {

>> -	while (pru->evt_count--) {

>> +	if (!pru->mapped_irq)

>> +		return;

>> +

>> +	while (pru->evt_count) {

>> +		pru->evt_count--;

>>  		if (pru->mapped_irq[pru->evt_count] > 0)

>>  			irq_dispose_mapping(pru->mapped_irq[pru->evt_count]);

>>  	}

>>  

>>  	kfree(pru->mapped_irq);

>> +	pru->mapped_irq = NULL;

>>  }

>>  

>>  /*

>> @@ -324,6 +329,8 @@ static int pru_handle_intrmap(struct rproc *rproc)

>>  	of_node_put(parent);

>>  	if (!irq_parent) {

>>  		kfree(pru->mapped_irq);

>> +		pru->mapped_irq = NULL;

>> +		pru->evt_count = 0;

> 

> Patch 1/3 introduced a check on @parent that doesn't free pru->mapped_irq.  I

> would also expect that error path to do the same has what is done here.  And

> looking further up I see the error path for !pru->mapped_irq doesn't set

> pru->evt_count to zero.


Good catch, thank you. I will fix these up in v2.

regards
Suman

> 

> Thanks,

> Mathieu

> 

>>  		return -ENODEV;

>>  	}

>>  

>> @@ -398,8 +405,7 @@ static int pru_rproc_stop(struct rproc *rproc)

>>  	pru_control_write_reg(pru, PRU_CTRL_CTRL, val);

>>  

>>  	/* dispose irq mapping - new firmware can provide new mapping */

>> -	if (pru->mapped_irq)

>> -		pru_dispose_irq_mapping(pru);

>> +	pru_dispose_irq_mapping(pru);

>>  

>>  	return 0;

>>  }

>> -- 

>> 2.30.1

>>
diff mbox series

Patch

diff --git a/drivers/remoteproc/pru_rproc.c b/drivers/remoteproc/pru_rproc.c
index 87b43976c51b..5df19acb90ed 100644
--- a/drivers/remoteproc/pru_rproc.c
+++ b/drivers/remoteproc/pru_rproc.c
@@ -266,12 +266,17 @@  static void pru_rproc_create_debug_entries(struct rproc *rproc)
 
 static void pru_dispose_irq_mapping(struct pru_rproc *pru)
 {
-	while (pru->evt_count--) {
+	if (!pru->mapped_irq)
+		return;
+
+	while (pru->evt_count) {
+		pru->evt_count--;
 		if (pru->mapped_irq[pru->evt_count] > 0)
 			irq_dispose_mapping(pru->mapped_irq[pru->evt_count]);
 	}
 
 	kfree(pru->mapped_irq);
+	pru->mapped_irq = NULL;
 }
 
 /*
@@ -324,6 +329,8 @@  static int pru_handle_intrmap(struct rproc *rproc)
 	of_node_put(parent);
 	if (!irq_parent) {
 		kfree(pru->mapped_irq);
+		pru->mapped_irq = NULL;
+		pru->evt_count = 0;
 		return -ENODEV;
 	}
 
@@ -398,8 +405,7 @@  static int pru_rproc_stop(struct rproc *rproc)
 	pru_control_write_reg(pru, PRU_CTRL_CTRL, val);
 
 	/* dispose irq mapping - new firmware can provide new mapping */
-	if (pru->mapped_irq)
-		pru_dispose_irq_mapping(pru);
+	pru_dispose_irq_mapping(pru);
 
 	return 0;
 }