svn commit: r311845 - head/sys/dev/rtwn/pci

[Andriy Voskoboinyk]

Author: avos
Date: Tue Jan 10 01:09:39 2017
New Revision: 311845
URL: https://svnweb.freebsd.org/changeset/base/311845

Log:
  rtwn_pci(4): fix possible race while accessing 'matched_chip' variable.

Modified:
  head/sys/dev/rtwn/pci/rtwn_pci_attach.c

Modified: head/sys/dev/rtwn/pci/rtwn_pci_attach.c
==============================================================================
--- head/sys/dev/rtwn/pci/rtwn_pci_attach.c	Tue Jan 10 00:28:01 2017	(r311844)
+++ head/sys/dev/rtwn/pci/rtwn_pci_attach.c	Tue Jan 10 01:09:39 2017	(r311845)
@@ -94,20 +94,31 @@ static void	rtwn_pci_beacon_update_end(s
 static void	rtwn_pci_attach_methods(struct rtwn_softc *);
 
 
-static int matched_chip = RTWN_CHIP_MAX_PCI;
+static const struct rtwn_pci_ident *
+rtwn_pci_probe_sub(device_t dev)
+{
+	const struct rtwn_pci_ident *ident;
+	int vendor_id, device_id;
+
+	vendor_id = pci_get_vendor(dev);
+	device_id = pci_get_device(dev);
+
+	for (ident = rtwn_pci_ident_table; ident->name != NULL; ident++)
+		if (vendor_id == ident->vendor && device_id == ident->device)
+			return (ident);
+
+	return (NULL);
+}
 
 static int
 rtwn_pci_probe(device_t dev)
 {
 	const struct rtwn_pci_ident *ident;
 
-	for (ident = rtwn_pci_ident_table; ident->name != NULL; ident++) {
-		if (pci_get_vendor(dev) == ident->vendor &&
-		    pci_get_device(dev) == ident->device) {
-			matched_chip = ident->chip;
-			device_set_desc(dev, ident->name);
-			return (BUS_PROBE_DEFAULT);
-		}
+	ident = rtwn_pci_probe_sub(dev);
+	if (ident != NULL) {
+		device_set_desc(dev, ident->name);
+		return (BUS_PROBE_DEFAULT);
 	}
 	return (ENXIO);
 }
@@ -591,13 +602,15 @@ rtwn_pci_attach_methods(struct rtwn_soft
 static int
 rtwn_pci_attach(device_t dev)
 {
+	const struct rtwn_pci_ident *ident;
 	struct rtwn_pci_softc *pc = device_get_softc(dev);
 	struct rtwn_softc *sc = &pc->pc_sc;
 	struct ieee80211com *ic = &sc->sc_ic;
 	uint32_t lcsr;
 	int cap_off, i, error, rid;
 
-	if (matched_chip >= RTWN_CHIP_MAX_PCI)
+	ident = rtwn_pci_probe_sub(dev);
+	if (ident == NULL)
 		return (ENXIO);
 
 	/*
@@ -649,8 +662,7 @@ rtwn_pci_attach(device_t dev)
 	mtx_init(&sc->sc_mtx, ic->ic_name, MTX_NETWORK_LOCK, MTX_DEF);
 
 	rtwn_pci_attach_methods(sc);
-	/* XXX something similar to USB_GET_DRIVER_INFO() */
-	rtwn_pci_attach_private(pc, matched_chip);
+	rtwn_pci_attach_private(pc, ident->chip);
 
 	/* Allocate Tx/Rx buffers. */
 	error = rtwn_pci_alloc_rx_list(sc);