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 was carried over from ancient times - "Fixed" commit just promoted the message from DEBUG to ERROR. Cc: [email protected] Fixes: 8c3d52fc393b ("HID: make parser more verbose about parsing errors by default") Signed-off-by: Michał Mirosław <[email protected]> --- v2: fixed printf() warning spotted by Jiri Kosina <[email protected]> * against v5.2.9 Signed-off-by: Michał Mirosław <[email protected]> --- drivers/hid/hid-core.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c index 210b81a56e1a..3af76624e4aa 100644 --- a/drivers/hid/hid-core.c +++ b/drivers/hid/hid-core.c @@ -1139,6 +1139,7 @@ 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) = { @@ -1192,7 +1193,8 @@ 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"); @@ -1230,7 +1232,8 @@ 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 %u/%u\n", + size - (unsigned int)(end - start), size); err: kfree(parser->collection_stack); alloc_err: -- 2.20.1
