HID: fix error message in hid_open_report()
diff mbox series

Message ID 11bfd688a4cded256ed5419ae93557542b95af3c.1561260511.git.mirq-linux@rere.qmqm.pl
State Superseded
Delegated to: Jiri Kosina
Headers show
Series
  • HID: fix error message in hid_open_report()
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Commit Message

Michał Mirosław June 23, 2019, 3:33 a.m. UTC
On HID report descriptor parsing error the code displays bogus
pointer instead of error offset (subtracts start=NULL from end).
Make the message more useful by displaying correct error offset
and include total buffer size for reference.

This is present since ancient times - "Fixed" commit just
promoted the message from DEBUG to ERROR.

Cc: stable@vger.kernel.org
Fixes: 8c3d52fc393b ("HID: make parser more verbose about parsing errors by default")
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>

---
 * against v5.1.13

---
 drivers/hid/hid-core.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

Patch
diff mbox series

diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
index 39eba8106d40..88b8db620b4a 100644
--- a/drivers/hid/hid-core.c
+++ b/drivers/hid/hid-core.c
@@ -1142,6 +1142,7 @@  int hid_open_report(struct hid_device *device)
 	__u8 *start;
 	__u8 *buf;
 	__u8 *end;
+	__u8 *next;
 	int ret;
 	static int (*dispatch_type[])(struct hid_parser *parser,
 				      struct hid_item *item) = {
@@ -1195,7 +1196,8 @@  int hid_open_report(struct hid_device *device)
 	device->collection_size = HID_DEFAULT_NUM_COLLECTIONS;
 
 	ret = -EINVAL;
-	while ((start = fetch_item(start, end, &item)) != NULL) {
+	while ((next = fetch_item(start, end, &item)) != NULL) {
+		start = next;
 
 		if (item.format != HID_ITEM_FORMAT_SHORT) {
 			hid_err(device, "unexpected long global item\n");
@@ -1233,7 +1235,8 @@  int hid_open_report(struct hid_device *device)
 		}
 	}
 
-	hid_err(device, "item fetching failed at offset %d\n", (int)(end - start));
+	hid_err(device, "item fetching failed at offset %zu/%zu\n",
+		size - (end - start), size);
 err:
 	kfree(parser->collection_stack);
 alloc_err: