Re: [PATCH v2 3/3] remoteproc: pru: Fix and cleanup firmware interrupt mapping logic

2021-04-07 Thread Mathieu Poirier 
On Wed, Apr 07, 2021 at 10:56:41AM -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 
> Signed-off-by: Suman Anna 
> ---
> v2:
>  - Fixed two additional cleanup paths in pru_handle_intrmap()
>addressing Mathieu's review comment
> v1: 
> https://patchwork.kernel.org/project/linux-remoteproc/patch/20210323223839.17464-4-s-a...@ti.com/
> 
>  drivers/remoteproc/pru_rproc.c | 22 +-
>  1 file changed, 17 insertions(+), 5 deletions(-)
>

Reviewed-by: Mathieu Poirier 
 
> diff --git a/drivers/remoteproc/pru_rproc.c b/drivers/remoteproc/pru_rproc.c
> index 87b43976c51b..04863bf23db8 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;
>  }
>  
>  /*
> @@ -307,8 +312,10 @@ static int pru_handle_intrmap(struct rproc *rproc)
>   pru->evt_count = rsc->num_evts;
>   pru->mapped_irq = kcalloc(pru->evt_count, sizeof(unsigned int),
> GFP_KERNEL);
> - if (!pru->mapped_irq)
> + if (!pru->mapped_irq) {
> + pru->evt_count = 0;
>   return -ENOMEM;
> + }
>  
>   /*
>* parse and fill in system event to interrupt channel and
> @@ -317,13 +324,19 @@ static int pru_handle_intrmap(struct rproc *rproc)
>* corresponding sibling PRUSS INTC node.
>*/
>   parent = of_get_parent(dev_of_node(pru->dev));
> - if (!parent)
> + if (!parent) {
> + kfree(pru->mapped_irq);
> + pru->mapped_irq = NULL;
> + pru->evt_count = 0;
>   return -ENODEV;
> + }
>  
>   irq_parent = of_get_child_by_name(parent, "interrupt-controller");
>   of_node_put(parent);
>   if (!irq_parent) {
>   kfree(pru->mapped_irq);
> + pru->mapped_irq = NULL;
> + pru->evt_count = 0;
>   return -ENODEV;
>   }
>  
> @@ -398,8 +411,7 @@ 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
>

[PATCH v2 3/3] remoteproc: pru: Fix and cleanup firmware interrupt mapping logic

2021-04-07 Thread Suman Anna 
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 
Signed-off-by: Suman Anna 
---
v2:
 - Fixed two additional cleanup paths in pru_handle_intrmap()
   addressing Mathieu's review comment
v1: 
https://patchwork.kernel.org/project/linux-remoteproc/patch/20210323223839.17464-4-s-a...@ti.com/

 drivers/remoteproc/pru_rproc.c | 22 +-
 1 file changed, 17 insertions(+), 5 deletions(-)

diff --git a/drivers/remoteproc/pru_rproc.c b/drivers/remoteproc/pru_rproc.c
index 87b43976c51b..04863bf23db8 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;
 }
 
 /*
@@ -307,8 +312,10 @@ static int pru_handle_intrmap(struct rproc *rproc)
pru->evt_count = rsc->num_evts;
pru->mapped_irq = kcalloc(pru->evt_count, sizeof(unsigned int),
  GFP_KERNEL);
-   if (!pru->mapped_irq)
+   if (!pru->mapped_irq) {
+   pru->evt_count = 0;
return -ENOMEM;
+   }
 
/*
 * parse and fill in system event to interrupt channel and
@@ -317,13 +324,19 @@ static int pru_handle_intrmap(struct rproc *rproc)
 * corresponding sibling PRUSS INTC node.
 */
parent = of_get_parent(dev_of_node(pru->dev));
-   if (!parent)
+   if (!parent) {
+   kfree(pru->mapped_irq);
+   pru->mapped_irq = NULL;
+   pru->evt_count = 0;
return -ENODEV;
+   }
 
irq_parent = of_get_child_by_name(parent, "interrupt-controller");
of_node_put(parent);
if (!irq_parent) {
kfree(pru->mapped_irq);
+   pru->mapped_irq = NULL;
+   pru->evt_count = 0;
return -ENODEV;
}
 
@@ -398,8 +411,7 @@ 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