diff mbox series

[v1,2/2] device property: Don't clear secondary pointer for shared primary firmware node

Message ID 20201022184100.71659-2-andriy.shevchenko@linux.intel.com
State Accepted
Commit 99aed9227073fb34ce2880cbc7063e04185a65e1
Headers show
Series None | expand

Commit Message

Andy Shevchenko Oct. 22, 2020, 6:41 p.m. UTC
It appears that firmware nodes can be shared between devices. In such case
when a (child) device is about to be deleted, its firmware node may be shared
and ACPI_COMPANION_SET(..., NULL) call for it breaks the secondary link
of the shared primary firmware node.

In order to prevent that, check, if the device has a parent and parent's
firmware node is shared with its child, and avoid crashing the link.

Fixes: c15e1bdda436 ("device property: Fix the secondary firmware node handling in set_primary_fwnode()")
Reported-by: Ferry Toth <fntoth@gmail.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 drivers/base/core.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

Comments

Heikki Krogerus Oct. 23, 2020, 12:35 p.m. UTC | #1
On Thu, Oct 22, 2020 at 09:41:00PM +0300, Andy Shevchenko wrote:
> It appears that firmware nodes can be shared between devices. In such case
> when a (child) device is about to be deleted, its firmware node may be shared
> and ACPI_COMPANION_SET(..., NULL) call for it breaks the secondary link
> of the shared primary firmware node.
> 
> In order to prevent that, check, if the device has a parent and parent's
> firmware node is shared with its child, and avoid crashing the link.
> 
> Fixes: c15e1bdda436 ("device property: Fix the secondary firmware node handling in set_primary_fwnode()")
> Reported-by: Ferry Toth <fntoth@gmail.com>
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

FWIW:

Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>

> ---
>  drivers/base/core.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/base/core.c b/drivers/base/core.c
> index 41feab679fa1..78114ddac755 100644
> --- a/drivers/base/core.c
> +++ b/drivers/base/core.c
> @@ -4264,6 +4264,7 @@ static inline bool fwnode_is_primary(struct fwnode_handle *fwnode)
>   */
>  void set_primary_fwnode(struct device *dev, struct fwnode_handle *fwnode)
>  {
> +	struct device *parent = dev->parent;
>  	struct fwnode_handle *fn = dev->fwnode;
>  
>  	if (fwnode) {
> @@ -4278,7 +4279,8 @@ void set_primary_fwnode(struct device *dev, struct fwnode_handle *fwnode)
>  	} else {
>  		if (fwnode_is_primary(fn)) {
>  			dev->fwnode = fn->secondary;
> -			fn->secondary = ERR_PTR(-ENODEV);
> +			if (!(parent && fn == parent->fwnode))
> +				fn->secondary = ERR_PTR(-ENODEV);
>  		} else {
>  			dev->fwnode = NULL;
>  		}
> -- 
> 2.28.0
Ferry Toth Oct. 23, 2020, 2:03 p.m. UTC | #2
Hi

Op 23-10-2020 om 14:35 schreef Heikki Krogerus:
> On Thu, Oct 22, 2020 at 09:41:00PM +0300, Andy Shevchenko wrote:
>> It appears that firmware nodes can be shared between devices. In such case
>> when a (child) device is about to be deleted, its firmware node may be shared
>> and ACPI_COMPANION_SET(..., NULL) call for it breaks the secondary link
>> of the shared primary firmware node.
>>
>> In order to prevent that, check, if the device has a parent and parent's
>> firmware node is shared with its child, and avoid crashing the link.
>>
>> Fixes: c15e1bdda436 ("device property: Fix the secondary firmware node handling in set_primary_fwnode()")
>> Reported-by: Ferry Toth <fntoth@gmail.com>
>> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> FWIW:
>
> Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>

Tested-by: Ferry Toth <fntoth@gmail.com>

>> ---
>>   drivers/base/core.c | 4 +++-
>>   1 file changed, 3 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/base/core.c b/drivers/base/core.c
>> index 41feab679fa1..78114ddac755 100644
>> --- a/drivers/base/core.c
>> +++ b/drivers/base/core.c
>> @@ -4264,6 +4264,7 @@ static inline bool fwnode_is_primary(struct fwnode_handle *fwnode)
>>    */
>>   void set_primary_fwnode(struct device *dev, struct fwnode_handle *fwnode)
>>   {
>> +	struct device *parent = dev->parent;
>>   	struct fwnode_handle *fn = dev->fwnode;
>>   
>>   	if (fwnode) {
>> @@ -4278,7 +4279,8 @@ void set_primary_fwnode(struct device *dev, struct fwnode_handle *fwnode)
>>   	} else {
>>   		if (fwnode_is_primary(fn)) {
>>   			dev->fwnode = fn->secondary;
>> -			fn->secondary = ERR_PTR(-ENODEV);
>> +			if (!(parent && fn == parent->fwnode))
>> +				fn->secondary = ERR_PTR(-ENODEV);
>>   		} else {
>>   			dev->fwnode = NULL;
>>   		}
>> -- 
>> 2.28.0
Ferry Toth Oct. 23, 2020, 2:16 p.m. UTC | #3
Hi

Op 23-10-2020 om 14:35 schreef Heikki Krogerus:
> On Thu, Oct 22, 2020 at 09:41:00PM +0300, Andy Shevchenko wrote:
>> It appears that firmware nodes can be shared between devices. In such 
>> case
>> when a (child) device is about to be deleted, its firmware node may 
>> be shared
>> and ACPI_COMPANION_SET(..., NULL) call for it breaks the secondary link
>> of the shared primary firmware node.
>>
>> In order to prevent that, check, if the device has a parent and parent's
>> firmware node is shared with its child, and avoid crashing the link.
>>
>> Fixes: c15e1bdda436 ("device property: Fix the secondary firmware 
>> node handling in set_primary_fwnode()")
>> Reported-by: Ferry Toth <fntoth@gmail.com>
>> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> FWIW:
>
> Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>

Tested-by: Ferry Toth <fntoth@gmail.com>

>> ---
>> drivers/base/core.c | 4 +++-
>> 1 file changed, 3 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/base/core.c b/drivers/base/core.c
>> index 41feab679fa1..78114ddac755 100644
>> --- a/drivers/base/core.c
>> +++ b/drivers/base/core.c
>> @@ -4264,6 +4264,7 @@ static inline bool fwnode_is_primary(struct 
>> fwnode_handle *fwnode)
>> */
>> void set_primary_fwnode(struct device *dev, struct fwnode_handle *fwnode)
>> {
>> + struct device *parent = dev->parent;
>> struct fwnode_handle *fn = dev->fwnode;
>> if (fwnode) {
>> @@ -4278,7 +4279,8 @@ void set_primary_fwnode(struct device *dev, 
>> struct fwnode_handle *fwnode)
>> } else {
>> if (fwnode_is_primary(fn)) {
>> dev->fwnode = fn->secondary;
>> - fn->secondary = ERR_PTR(-ENODEV);
>> + if (!(parent && fn == parent->fwnode))
>> + fn->secondary = ERR_PTR(-ENODEV);
>> } else {
>> dev->fwnode = NULL;
>> }
>> -- 2.28.0
diff mbox series

Patch

diff --git a/drivers/base/core.c b/drivers/base/core.c
index 41feab679fa1..78114ddac755 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -4264,6 +4264,7 @@  static inline bool fwnode_is_primary(struct fwnode_handle *fwnode)
  */
 void set_primary_fwnode(struct device *dev, struct fwnode_handle *fwnode)
 {
+	struct device *parent = dev->parent;
 	struct fwnode_handle *fn = dev->fwnode;
 
 	if (fwnode) {
@@ -4278,7 +4279,8 @@  void set_primary_fwnode(struct device *dev, struct fwnode_handle *fwnode)
 	} else {
 		if (fwnode_is_primary(fn)) {
 			dev->fwnode = fn->secondary;
-			fn->secondary = ERR_PTR(-ENODEV);
+			if (!(parent && fn == parent->fwnode))
+				fn->secondary = ERR_PTR(-ENODEV);
 		} else {
 			dev->fwnode = NULL;
 		}