From: jsg <jsg@openbsd.org>
Date: Mon, 22 Nov 2021 14:00:52 +0000 (+0000)
Subject: avoid uninitialised variable use in igc(4)
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=7a97ce60e5846ec420cbeccaad2c20de656ff44e;p=openbsd

avoid uninitialised variable use in igc(4)

read icr reg before testing bit in result
add missing block in rxeof from ix

ok kevlo@ patrick@
---

diff --git a/sys/dev/pci/if_igc.c b/sys/dev/pci/if_igc.c
index 875a3eb5bd1..e66ca876133 100644
--- a/sys/dev/pci/if_igc.c
+++ b/sys/dev/pci/if_igc.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: if_igc.c,v 1.4 2021/10/31 15:25:10 patrick Exp $	*/
+/*	$OpenBSD: if_igc.c,v 1.5 2021/11/22 14:00:52 jsg Exp $	*/
 /*-
  * SPDX-License-Identifier: BSD-2-Clause
  *
@@ -1283,7 +1283,7 @@ igc_rxeof(struct rx_ring *rxr)
 	uint32_t ptype, staterr = 0;
 	uint16_t len, vtag;
 	uint8_t eop = 0;
-	int i;
+	int i, nextp;
 
 	if (!ISSET(ifp->if_flags, IFF_RUNNING))
 		return 0;
@@ -1342,6 +1342,17 @@ igc_rxeof(struct rx_ring *rxr)
 			    if_rxr_inuse(&rxr->rx_ring), rxr->last_desc_filled);
 		}
 
+		if (!eop) {
+			/*
+			 * Figure out the next descriptor of this frame.
+			 */
+			nextp = i + 1;
+			if (nextp == sc->num_rx_desc)
+				nextp = 0;
+			nxbuf = &rxr->rx_buffers[nextp];
+			/* prefetch(nxbuf); */
+		}
+
 		mp->m_len = len;
 
 		m = rxbuf->fmp;
@@ -1736,7 +1747,7 @@ int
 igc_intr_link(void *arg)
 {
 	struct igc_softc *sc = (struct igc_softc *)arg;
-	uint32_t reg_icr;
+	uint32_t reg_icr = IGC_READ_REG(&sc->hw, IGC_ICR);
 
 	if (reg_icr & IGC_ICR_LSC) {
 		KERNEL_LOCK();