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@xxxxxxxxx>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
FWIW:
Reviewed-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
Tested-by: Ferry Toth <fntoth@xxxxxxxxx>
---
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
