Commit 7d1d3882 authored by Rui Miguel Silva's avatar Rui Miguel Silva Committed by Greg Kroah-Hartman
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usb: isp1760: do not shift in uninitialized slot 



Even though it is not expected, and would trigger a WARN_ON, killing a
transfer in a uninitialized slot this sequence is warned by clang
analyzer, twice:

drivers/usb/isp1760/isp1760-hcd.c:1976:18: warning: The result of the left shift is undefined because the right operand is negative [clang-analyzer-core.UndefinedBinaryOperatorResult]
                skip_map |= (1 << qh->slot);
drivers/usb/isp1760/isp1760-hcd.c:1983:18: warning: The result of the left shift is undefined because the right operand is negative [clang-analyzer-core.UndefinedBinaryOperatorResult]
                skip_map |= (1 << qh->slot);

Only set skip map if slot is active.

Signed-off-by: default avatarRui Miguel Silva <rui.silva@linaro.org>
Link: https://lore.kernel.org/r/20210819180929.1327349-5-rui.silva@linaro.org


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 5e4cd1b6

drivers/usb/isp1760/isp1760-hcd.c

+11 −7
Original line number Diff line number Diff line
@@ -1974,16 +1974,20 @@ static void kill_transfer(struct usb_hcd *hcd, struct urb *urb, 
	/* We need to forcefully reclaim the slot since some transfers never

	   return, e.g. interrupt transfers and NAKed bulk transfers. */

	if (usb_pipecontrol(urb->pipe) || usb_pipebulk(urb->pipe)) {

		if (qh->slot != -1) {

			skip_map = isp1760_hcd_read(hcd, HC_ATL_PTD_SKIPMAP);

			skip_map |= (1 << qh->slot);

			isp1760_hcd_write(hcd, HC_ATL_PTD_SKIPMAP, skip_map);

			ndelay(100);

		}

		priv->atl_slots[qh->slot].qh = NULL;

		priv->atl_slots[qh->slot].qtd = NULL;

	} else {

		if (qh->slot != -1) {

			skip_map = isp1760_hcd_read(hcd, HC_INT_PTD_SKIPMAP);

			skip_map |= (1 << qh->slot);

			isp1760_hcd_write(hcd, HC_INT_PTD_SKIPMAP, skip_map);

		}

		priv->int_slots[qh->slot].qh = NULL;

		priv->int_slots[qh->slot].qtd = NULL;

	}