Hi On Thu, Dec 19, 2013 at 11:08 AM, David Herrmann <dh.herrmann@xxxxxxxxx> wrote: > Hi > > On Thu, Dec 19, 2013 at 10:59 AM, Jiri Kosina <jkosina@xxxxxxx> wrote: >> On Thu, 19 Dec 2013, David Herrmann wrote: >> >>> > diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c >>> > index 253fe23..81eacd3 100644 >>> > --- a/drivers/hid/hid-core.c >>> > +++ b/drivers/hid/hid-core.c >>> > @@ -1334,7 +1334,7 @@ int hid_report_raw_event(struct hid_device *hid, int type, u8 *data, int size, >>> > csize--; >>> > } >>> > >>> > - rsize = ((report->size - 1) >> 3) + 1; >>> > + rsize = ((report->size - 1) >> 3) + 1 + (report->id > 0) + 7; >>> >>> Isn't "report->id" already covered by "if (report_enum->numbered)" >>> above? The test for "id > 0" won't work here as in this case >>> "report_enum->numbered" must already be set to true by the hid-desc >>> parser, doesn't it? >> >> Right, that one is not correct here, thanks. >> >>> Where exactly did you get the +7 from? >> >> Please see commit (the one I am not really proud of) 27ce405039bfe6d3. > > Eh, I remember.. Ok, but the magic-mouse is BT right? So this commit > really breaks BT drivers: > > commit b1a1442a23776756b254b69786848a94d92445ba > Author: Jiri Kosina <jkosina@xxxxxxx> > Date: Mon Jun 3 11:27:48 2013 +0200 > > HID: core: fix reporting of raw events > > Problem is, if the raw_event() callback returned 0 earlier, we just > skipped raw input reports. However, we now always call the > hid_report_raw_event() helper. Which is normally fine, but the helper > expects the input buffer to be of size HID_MAX_REPORT_SIZE, which is > *not* true for HIDP. So the memset() writes over some random memory. > > I don't know exactly how to fix it. HID_MAX_BUFFER_SIZE is too big to > be allocated on the stack, but we're in atomic-context here so a > kzalloc(rsize, GFP_ATOMIC) seems overkill. So I guess we'd have to > look into HIDP to make the skb big enough, but I'm not sure how we can > achieve that. > > So off the top of my head, the best idea is to add "char > inbuf[HID_MAX_BUFFER_SIZE];" to the hidp_session object in HIDP and > copy every input-report into the buffer before passing to > hid_input_report(). As this thread doesn't really contain any oops message nor the exact driver name (except mentioning hyperv and magicmouse), I fixed a related bug for HIDP: http://thread.gmane.org/gmane.linux.bluez.kernel/41969 A similar patch is *really* required for hid-hyperv.c as it also does not provide a properly sized buffer to hid_input_report(). David _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
