Sometimes it is better to unregister individual nodes instead of trying
to do them all at once with software_node_unregister_nodes(), so create
software_node_unregister() so that you can unregister them one at a
time.
This is especially important when creating nodes in a hierarchy, with
parent -> children representations. Children always need to be removed
before a parent is, as the swnode logic assumes this is going to be the
case.
Fix up the lib/test_printf.c fwnode_pointer() test which to use this new
function as it had the problem of tearing things down in the backwards
order.
Fixes: f1ce39df508d ("lib/test_printf: Add tests for %pfw printk modifier")
Reported-by: Naresh Kamboju <[email protected]>
Reported-by: kernel test robot <[email protected]>
Cc: stable <[email protected]>
Cc: Andy Shevchenko <[email protected]>
Cc: Brendan Higgins <[email protected]>
Cc: Dmitry Torokhov <[email protected]>
Cc: Heikki Krogerus <[email protected]>
Cc: Petr Mladek <[email protected]>
Cc: Rafael J. Wysocki <[email protected]>
Cc: Randy Dunlap <[email protected]>
Cc: Rasmus Villemoes <[email protected]>
Cc: Sakari Ailus <[email protected]>
Cc: Sergey Senozhatsky <[email protected]>
Cc: Steven Rostedt <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
drivers/base/swnode.c | 27 +++++++++++++++++++++------
include/linux/property.h | 1 +
lib/test_printf.c | 4 +++-
3 files changed, 25 insertions(+), 7 deletions(-)
diff --git a/drivers/base/swnode.c b/drivers/base/swnode.c
index de8d3543e8fe..770b1f47a625 100644
--- a/drivers/base/swnode.c
+++ b/drivers/base/swnode.c
@@ -712,17 +712,18 @@ EXPORT_SYMBOL_GPL(software_node_register_nodes);
* @nodes: Zero terminated array of software nodes to be unregistered
*
* Unregister multiple software nodes at once.
+ *
+ * NOTE: Be careful using this call if the nodes had parent pointers set up in
+ * them before registering. If so, it is wiser to remove the nodes
+ * individually, in the correct order (child before parent) instead of relying
+ * on the sequential order of the list of nodes in the array.
*/
void software_node_unregister_nodes(const struct software_node *nodes)
{
- struct swnode *swnode;
int i;
- for (i = 0; nodes[i].name; i++) {
- swnode = software_node_to_swnode(&nodes[i]);
- if (swnode)
- fwnode_remove_software_node(&swnode->fwnode);
- }
+ for (i = 0; nodes[i].name; i++)
+ software_node_unregister(&nodes[i]);
}
EXPORT_SYMBOL_GPL(software_node_unregister_nodes);
@@ -741,6 +742,20 @@ int software_node_register(const struct software_node *node)
}
EXPORT_SYMBOL_GPL(software_node_register);
+/**
+ * software_node_unregister - Unregister static software node
+ * @node: The software node to be unregistered
+ */
+void software_node_unregister(const struct software_node *node)
+{
+ struct swnode *swnode;
+
+ swnode = software_node_to_swnode(node);
+ if (swnode)
+ fwnode_remove_software_node(&swnode->fwnode);
+}
+EXPORT_SYMBOL_GPL(software_node_unregister);
+
struct fwnode_handle *
fwnode_create_software_node(const struct property_entry *properties,
const struct fwnode_handle *parent)
diff --git a/include/linux/property.h b/include/linux/property.h
index d86de017c689..0d4099b4ce1f 100644
--- a/include/linux/property.h
+++ b/include/linux/property.h
@@ -441,6 +441,7 @@ int software_node_register_nodes(const struct software_node *nodes);
void software_node_unregister_nodes(const struct software_node *nodes);
int software_node_register(const struct software_node *node);
+void software_node_unregister(const struct software_node *node);
int software_node_notify(struct device *dev, unsigned long action);
diff --git a/lib/test_printf.c b/lib/test_printf.c
index 6b1622f4d7c2..fc63b8959d42 100644
--- a/lib/test_printf.c
+++ b/lib/test_printf.c
@@ -637,7 +637,9 @@ static void __init fwnode_pointer(void)
test(second_name, "%pfwP", software_node_fwnode(&softnodes[1]));
test(third_name, "%pfwP", software_node_fwnode(&softnodes[2]));
- software_node_unregister_nodes(softnodes);
+ software_node_unregister(&softnodes[2]);
+ software_node_unregister(&softnodes[1]);
+ software_node_unregister(&softnodes[0]);
}
static void __init
--
2.26.2
On 5/24/20 8:30 AM, Greg Kroah-Hartman wrote:
> Sometimes it is better to unregister individual nodes instead of trying
> to do them all at once with software_node_unregister_nodes(), so create
> software_node_unregister() so that you can unregister them one at a
> time.
>
> This is especially important when creating nodes in a hierarchy, with
> parent -> children representations. Children always need to be removed
> before a parent is, as the swnode logic assumes this is going to be the
> case.
>
> Fix up the lib/test_printf.c fwnode_pointer() test which to use this new
> function as it had the problem of tearing things down in the backwards
> order.
>
> Fixes: f1ce39df508d ("lib/test_printf: Add tests for %pfw printk modifier")
> Reported-by: Naresh Kamboju <[email protected]>
> Reported-by: kernel test robot <[email protected]>
> Cc: stable <[email protected]>
> Cc: Andy Shevchenko <[email protected]>
> Cc: Brendan Higgins <[email protected]>
> Cc: Dmitry Torokhov <[email protected]>
> Cc: Heikki Krogerus <[email protected]>
> Cc: Petr Mladek <[email protected]>
> Cc: Rafael J. Wysocki <[email protected]>
> Cc: Randy Dunlap <[email protected]>
> Cc: Rasmus Villemoes <[email protected]>
> Cc: Sakari Ailus <[email protected]>
> Cc: Sergey Senozhatsky <[email protected]>
> Cc: Steven Rostedt <[email protected]>
> Signed-off-by: Greg Kroah-Hartman <[email protected]>
Both patches pass my boot tests on arm64 and arm64be (I didn't test any others).
So, FWIW,
Tested-by: Guenter Roeck <[email protected]>
I wasn't sure it the two patches replace or fix commit 4ef12f719802 ("kobject:
Make sure the parent does not get released before its children"), so I tried
to re-apply 4ef12f719802 on top of the two patches. Unfortunately that still
results in crashes and UAF messages.
Guenter
On 5/24/20 9:43 AM, Guenter Roeck wrote:
> On 5/24/20 8:30 AM, Greg Kroah-Hartman wrote:
>> Sometimes it is better to unregister individual nodes instead of trying
>> to do them all at once with software_node_unregister_nodes(), so create
>> software_node_unregister() so that you can unregister them one at a
>> time.
>>
>> This is especially important when creating nodes in a hierarchy, with
>> parent -> children representations. Children always need to be removed
>> before a parent is, as the swnode logic assumes this is going to be the
>> case.
>>
>> Fix up the lib/test_printf.c fwnode_pointer() test which to use this new
>> function as it had the problem of tearing things down in the backwards
>> order.
>>
>> Fixes: f1ce39df508d ("lib/test_printf: Add tests for %pfw printk modifier")
>> Reported-by: Naresh Kamboju <[email protected]>
>> Reported-by: kernel test robot <[email protected]>
>> Cc: stable <[email protected]>
>> Cc: Andy Shevchenko <[email protected]>
>> Cc: Brendan Higgins <[email protected]>
>> Cc: Dmitry Torokhov <[email protected]>
>> Cc: Heikki Krogerus <[email protected]>
>> Cc: Petr Mladek <[email protected]>
>> Cc: Rafael J. Wysocki <[email protected]>
>> Cc: Randy Dunlap <[email protected]>
>> Cc: Rasmus Villemoes <[email protected]>
>> Cc: Sakari Ailus <[email protected]>
>> Cc: Sergey Senozhatsky <[email protected]>
>> Cc: Steven Rostedt <[email protected]>
>> Signed-off-by: Greg Kroah-Hartman <[email protected]>
>
> Both patches pass my boot tests on arm64 and arm64be (I didn't test any others).
> So, FWIW,
>
> Tested-by: Guenter Roeck <[email protected]>
>
> I wasn't sure it the two patches replace or fix commit 4ef12f719802 ("kobject:
> Make sure the parent does not get released before its children"), so I tried
> to re-apply 4ef12f719802 on top of the two patches. Unfortunately that still
> results in crashes and UAF messages.
Yes, that kobject patch has been reverted:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=e6764aa0e5530066dd969eccea2a1a7d177859a8
and these 2 patches are to be used instead.
thanks.
--
~Randy
On Sun 2020-05-24 17:30:40, Greg Kroah-Hartman wrote:
> Sometimes it is better to unregister individual nodes instead of trying
> to do them all at once with software_node_unregister_nodes(), so create
> software_node_unregister() so that you can unregister them one at a
> time.
>
> This is especially important when creating nodes in a hierarchy, with
> parent -> children representations. Children always need to be removed
> before a parent is, as the swnode logic assumes this is going to be the
> case.
>
> Fix up the lib/test_printf.c fwnode_pointer() test which to use this new
> function as it had the problem of tearing things down in the backwards
> order.
>
> Fixes: f1ce39df508d ("lib/test_printf: Add tests for %pfw printk modifier")
> Reported-by: Naresh Kamboju <[email protected]>
> Reported-by: kernel test robot <[email protected]>
> Cc: stable <[email protected]>
> Cc: Andy Shevchenko <[email protected]>
> Cc: Brendan Higgins <[email protected]>
> Cc: Dmitry Torokhov <[email protected]>
> Cc: Heikki Krogerus <[email protected]>
> Cc: Petr Mladek <[email protected]>
> Cc: Rafael J. Wysocki <[email protected]>
> Cc: Randy Dunlap <[email protected]>
> Cc: Rasmus Villemoes <[email protected]>
> Cc: Sakari Ailus <[email protected]>
> Cc: Sergey Senozhatsky <[email protected]>
> Cc: Steven Rostedt <[email protected]>
> Signed-off-by: Greg Kroah-Hartman <[email protected]>
I could confirm that this fixed lib/test_printf.c. The patch looks reasonable.
Tested-by: Petr Mladek <[email protected]>
Best Regards,
Petr
On Sun, May 24, 2020 at 05:30:40PM +0200, Greg Kroah-Hartman wrote:
> Sometimes it is better to unregister individual nodes instead of trying
> to do them all at once with software_node_unregister_nodes(), so create
> software_node_unregister() so that you can unregister them one at a
> time.
>
> This is especially important when creating nodes in a hierarchy, with
> parent -> children representations. Children always need to be removed
> before a parent is, as the swnode logic assumes this is going to be the
> case.
>
> Fix up the lib/test_printf.c fwnode_pointer() test which to use this new
> function as it had the problem of tearing things down in the backwards
> order.
>
> Fixes: f1ce39df508d ("lib/test_printf: Add tests for %pfw printk modifier")
> Reported-by: Naresh Kamboju <[email protected]>
> Reported-by: kernel test robot <[email protected]>
> Cc: stable <[email protected]>
> Cc: Andy Shevchenko <[email protected]>
> Cc: Brendan Higgins <[email protected]>
> Cc: Dmitry Torokhov <[email protected]>
> Cc: Heikki Krogerus <[email protected]>
> Cc: Petr Mladek <[email protected]>
> Cc: Rafael J. Wysocki <[email protected]>
> Cc: Randy Dunlap <[email protected]>
> Cc: Rasmus Villemoes <[email protected]>
> Cc: Sakari Ailus <[email protected]>
> Cc: Sergey Senozhatsky <[email protected]>
> Cc: Steven Rostedt <[email protected]>
> Signed-off-by: Greg Kroah-Hartman <[email protected]>
FWIW:
Reviewed-by: Heikki Krogerus <[email protected]>
> ---
> drivers/base/swnode.c | 27 +++++++++++++++++++++------
> include/linux/property.h | 1 +
> lib/test_printf.c | 4 +++-
> 3 files changed, 25 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/base/swnode.c b/drivers/base/swnode.c
> index de8d3543e8fe..770b1f47a625 100644
> --- a/drivers/base/swnode.c
> +++ b/drivers/base/swnode.c
> @@ -712,17 +712,18 @@ EXPORT_SYMBOL_GPL(software_node_register_nodes);
> * @nodes: Zero terminated array of software nodes to be unregistered
> *
> * Unregister multiple software nodes at once.
> + *
> + * NOTE: Be careful using this call if the nodes had parent pointers set up in
> + * them before registering. If so, it is wiser to remove the nodes
> + * individually, in the correct order (child before parent) instead of relying
> + * on the sequential order of the list of nodes in the array.
> */
> void software_node_unregister_nodes(const struct software_node *nodes)
> {
> - struct swnode *swnode;
> int i;
>
> - for (i = 0; nodes[i].name; i++) {
> - swnode = software_node_to_swnode(&nodes[i]);
> - if (swnode)
> - fwnode_remove_software_node(&swnode->fwnode);
> - }
> + for (i = 0; nodes[i].name; i++)
> + software_node_unregister(&nodes[i]);
> }
> EXPORT_SYMBOL_GPL(software_node_unregister_nodes);
>
> @@ -741,6 +742,20 @@ int software_node_register(const struct software_node *node)
> }
> EXPORT_SYMBOL_GPL(software_node_register);
>
> +/**
> + * software_node_unregister - Unregister static software node
> + * @node: The software node to be unregistered
> + */
> +void software_node_unregister(const struct software_node *node)
> +{
> + struct swnode *swnode;
> +
> + swnode = software_node_to_swnode(node);
> + if (swnode)
> + fwnode_remove_software_node(&swnode->fwnode);
> +}
> +EXPORT_SYMBOL_GPL(software_node_unregister);
> +
> struct fwnode_handle *
> fwnode_create_software_node(const struct property_entry *properties,
> const struct fwnode_handle *parent)
> diff --git a/include/linux/property.h b/include/linux/property.h
> index d86de017c689..0d4099b4ce1f 100644
> --- a/include/linux/property.h
> +++ b/include/linux/property.h
> @@ -441,6 +441,7 @@ int software_node_register_nodes(const struct software_node *nodes);
> void software_node_unregister_nodes(const struct software_node *nodes);
>
> int software_node_register(const struct software_node *node);
> +void software_node_unregister(const struct software_node *node);
>
> int software_node_notify(struct device *dev, unsigned long action);
>
> diff --git a/lib/test_printf.c b/lib/test_printf.c
> index 6b1622f4d7c2..fc63b8959d42 100644
> --- a/lib/test_printf.c
> +++ b/lib/test_printf.c
> @@ -637,7 +637,9 @@ static void __init fwnode_pointer(void)
> test(second_name, "%pfwP", software_node_fwnode(&softnodes[1]));
> test(third_name, "%pfwP", software_node_fwnode(&softnodes[2]));
>
> - software_node_unregister_nodes(softnodes);
> + software_node_unregister(&softnodes[2]);
> + software_node_unregister(&softnodes[1]);
> + software_node_unregister(&softnodes[0]);
> }
>
> static void __init
> --
> 2.26.2
thanks,
--
heikki
On 5/24/20 8:30 AM, Greg Kroah-Hartman wrote:
> Sometimes it is better to unregister individual nodes instead of trying
> to do them all at once with software_node_unregister_nodes(), so create
> software_node_unregister() so that you can unregister them one at a
> time.
>
> This is especially important when creating nodes in a hierarchy, with
> parent -> children representations. Children always need to be removed
> before a parent is, as the swnode logic assumes this is going to be the
> case.
>
> Fix up the lib/test_printf.c fwnode_pointer() test which to use this new
> function as it had the problem of tearing things down in the backwards
> order.
>
> Fixes: f1ce39df508d ("lib/test_printf: Add tests for %pfw printk modifier")
> Reported-by: Naresh Kamboju <[email protected]>
> Reported-by: kernel test robot <[email protected]>
> Cc: stable <[email protected]>
> Cc: Andy Shevchenko <[email protected]>
> Cc: Brendan Higgins <[email protected]>
> Cc: Dmitry Torokhov <[email protected]>
> Cc: Heikki Krogerus <[email protected]>
> Cc: Petr Mladek <[email protected]>
> Cc: Rafael J. Wysocki <[email protected]>
> Cc: Randy Dunlap <[email protected]>
> Cc: Rasmus Villemoes <[email protected]>
> Cc: Sakari Ailus <[email protected]>
> Cc: Sergey Senozhatsky <[email protected]>
> Cc: Steven Rostedt <[email protected]>
> Signed-off-by: Greg Kroah-Hartman <[email protected]>
Reported-by: Randy Dunlap <[email protected]>
Acked-by: Randy Dunlap <[email protected]>
Tested-by: Randy Dunlap <[email protected]>
thanks.
> ---
> drivers/base/swnode.c | 27 +++++++++++++++++++++------
> include/linux/property.h | 1 +
> lib/test_printf.c | 4 +++-
> 3 files changed, 25 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/base/swnode.c b/drivers/base/swnode.c
> index de8d3543e8fe..770b1f47a625 100644
> --- a/drivers/base/swnode.c
> +++ b/drivers/base/swnode.c
> @@ -712,17 +712,18 @@ EXPORT_SYMBOL_GPL(software_node_register_nodes);
> * @nodes: Zero terminated array of software nodes to be unregistered
> *
> * Unregister multiple software nodes at once.
> + *
> + * NOTE: Be careful using this call if the nodes had parent pointers set up in
> + * them before registering. If so, it is wiser to remove the nodes
> + * individually, in the correct order (child before parent) instead of relying
> + * on the sequential order of the list of nodes in the array.
> */
> void software_node_unregister_nodes(const struct software_node *nodes)
> {
> - struct swnode *swnode;
> int i;
>
> - for (i = 0; nodes[i].name; i++) {
> - swnode = software_node_to_swnode(&nodes[i]);
> - if (swnode)
> - fwnode_remove_software_node(&swnode->fwnode);
> - }
> + for (i = 0; nodes[i].name; i++)
> + software_node_unregister(&nodes[i]);
> }
> EXPORT_SYMBOL_GPL(software_node_unregister_nodes);
>
> @@ -741,6 +742,20 @@ int software_node_register(const struct software_node *node)
> }
> EXPORT_SYMBOL_GPL(software_node_register);
>
> +/**
> + * software_node_unregister - Unregister static software node
> + * @node: The software node to be unregistered
> + */
> +void software_node_unregister(const struct software_node *node)
> +{
> + struct swnode *swnode;
> +
> + swnode = software_node_to_swnode(node);
> + if (swnode)
> + fwnode_remove_software_node(&swnode->fwnode);
> +}
> +EXPORT_SYMBOL_GPL(software_node_unregister);
> +
> struct fwnode_handle *
> fwnode_create_software_node(const struct property_entry *properties,
> const struct fwnode_handle *parent)
> diff --git a/include/linux/property.h b/include/linux/property.h
> index d86de017c689..0d4099b4ce1f 100644
> --- a/include/linux/property.h
> +++ b/include/linux/property.h
> @@ -441,6 +441,7 @@ int software_node_register_nodes(const struct software_node *nodes);
> void software_node_unregister_nodes(const struct software_node *nodes);
>
> int software_node_register(const struct software_node *node);
> +void software_node_unregister(const struct software_node *node);
>
> int software_node_notify(struct device *dev, unsigned long action);
>
> diff --git a/lib/test_printf.c b/lib/test_printf.c
> index 6b1622f4d7c2..fc63b8959d42 100644
> --- a/lib/test_printf.c
> +++ b/lib/test_printf.c
> @@ -637,7 +637,9 @@ static void __init fwnode_pointer(void)
> test(second_name, "%pfwP", software_node_fwnode(&softnodes[1]));
> test(third_name, "%pfwP", software_node_fwnode(&softnodes[2]));
>
> - software_node_unregister_nodes(softnodes);
> + software_node_unregister(&softnodes[2]);
> + software_node_unregister(&softnodes[1]);
> + software_node_unregister(&softnodes[0]);
> }
>
> static void __init
>
--
~Randy
On Sun, May 24, 2020 at 8:31 AM Greg Kroah-Hartman
<[email protected]> wrote:
>
> Sometimes it is better to unregister individual nodes instead of trying
> to do them all at once with software_node_unregister_nodes(), so create
> software_node_unregister() so that you can unregister them one at a
> time.
>
> This is especially important when creating nodes in a hierarchy, with
> parent -> children representations. Children always need to be removed
> before a parent is, as the swnode logic assumes this is going to be the
> case.
>
> Fix up the lib/test_printf.c fwnode_pointer() test which to use this new
> function as it had the problem of tearing things down in the backwards
> order.
>
> Fixes: f1ce39df508d ("lib/test_printf: Add tests for %pfw printk modifier")
> Reported-by: Naresh Kamboju <[email protected]>
> Reported-by: kernel test robot <[email protected]>
> Cc: stable <[email protected]>
> Cc: Andy Shevchenko <[email protected]>
> Cc: Brendan Higgins <[email protected]>
> Cc: Dmitry Torokhov <[email protected]>
> Cc: Heikki Krogerus <[email protected]>
> Cc: Petr Mladek <[email protected]>
> Cc: Rafael J. Wysocki <[email protected]>
> Cc: Randy Dunlap <[email protected]>
> Cc: Rasmus Villemoes <[email protected]>
> Cc: Sakari Ailus <[email protected]>
> Cc: Sergey Senozhatsky <[email protected]>
> Cc: Steven Rostedt <[email protected]>
> Signed-off-by: Greg Kroah-Hartman <[email protected]>
Sorry, I was on vacation.
Seems like this has already been sufficiently reviewed and applied.
Nevertheless,
Tested-by: Brendan Higgins <[email protected]>