Commit 08a8a7cf authored by Benjamin Tissoires's avatar Benjamin Tissoires Committed by Jiri Kosina
Browse files

HID: core: do not upper bound the collection stack 



Looks like 4 was sufficient until now. However, the Surface Dial needs
a stack of 5 and simply fails at probing.
Dynamically add HID_COLLECTION_STACK_SIZE to the size of the stack if
we hit the upper bound.

Checkpatch complains about bare unsigned, so converting those to
'unsigned int' in struct hid_parser

Acked-by: default avatarPeter Hutterer <peter.hutterer@who-t.net>
Signed-off-by: default avatarBenjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: default avatarJiri Kosina <jkosina@suse.cz>
parent ba6b055e

drivers/hid/hid-core.c

+14 −3
Original line number Diff line number Diff line
@@ -128,9 +128,19 @@ static int open_collection(struct hid_parser *parser, unsigned type) 


	usage = parser->local.usage[0];



	if (parser->collection_stack_ptr == HID_COLLECTION_STACK_SIZE) {

		hid_err(parser->device, "collection stack overflow\n");

		return -EINVAL;

	if (parser->collection_stack_ptr == parser->collection_stack_size) {

		unsigned int *collection_stack;

		unsigned int new_size = parser->collection_stack_size +

					HID_COLLECTION_STACK_SIZE;



		collection_stack = krealloc(parser->collection_stack,

					    new_size * sizeof(unsigned int),

					    GFP_KERNEL);

		if (!collection_stack)

			return -ENOMEM;



		parser->collection_stack = collection_stack;

		parser->collection_stack_size = new_size;

	}



	if (parser->device->maxcollection == parser->device->collection_size) {
@@ -840,6 +850,7 @@ static int hid_scan_report(struct hid_device *hid) 
		break;

	}



	kfree(parser->collection_stack);

	vfree(parser);

	return 0;

}

include/linux/hid.h

+5 −4
Original line number Diff line number Diff line
@@ -644,12 +644,13 @@ static inline void hid_set_drvdata(struct hid_device *hdev, void *data) 
struct hid_parser {

	struct hid_global     global;

	struct hid_global     global_stack[HID_GLOBAL_STACK_SIZE];

	unsigned              global_stack_ptr;

	unsigned int          global_stack_ptr;

	struct hid_local      local;

	unsigned              collection_stack[HID_COLLECTION_STACK_SIZE];

	unsigned              collection_stack_ptr;

	unsigned int         *collection_stack;

	unsigned int          collection_stack_ptr;

	unsigned int          collection_stack_size;

	struct hid_device    *device;

	unsigned              scan_flags;

	unsigned int          scan_flags;

};



struct hid_class_descriptor {

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