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

2020-10-23 Thread Ferry Toth

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 
Signed-off-by: Andy Shevchenko 

FWIW:

Reviewed-by: Heikki Krogerus 


Tested-by: Ferry Toth 


---
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


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

2020-10-23 Thread Ferry Toth

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 
Signed-off-by: Andy Shevchenko 

FWIW:

Reviewed-by: Heikki Krogerus 


Tested-by: Ferry Toth 


---
  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


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

2020-10-23 Thread 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 
> Signed-off-by: Andy Shevchenko 

FWIW:

Reviewed-by: Heikki Krogerus 

> ---
>  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

-- 
heikki


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

2020-10-22 Thread Andy Shevchenko
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 
Signed-off-by: Andy Shevchenko 
---
 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