Re: oops in ioapic_write_entry

[Yinghai Lu <yinghai@kernel.org>]

Please check if this one address your concerns.

Thanks

Yinghai

---
 arch/x86/kernel/mpparse.c |   88 ++++++++++++++++++++++++++++++++++++++++------
 1 file changed, 77 insertions(+), 11 deletions(-)

Index: linux-2.6/arch/x86/kernel/mpparse.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/mpparse.c
+++ linux-2.6/arch/x86/kernel/mpparse.c
@@ -173,17 +173,17 @@ static int __init mp_irq_mpc_intsrc_cmp(
 {
 	if (mp_irq->dstapic != m->dstapic)
 		return 1;
-	if (mp_irq->type != m->type)
+	if (mp_irq->dstirq != m->dstirq)
 		return 2;
-	if (mp_irq->irqtype != m->irqtype)
+	if (mp_irq->srcbus != m->srcbus)
 		return 3;
-	if (mp_irq->irqflag != m->irqflag)
+	if (mp_irq->type != m->type)
 		return 4;
-	if (mp_irq->srcbus != m->srcbus)
+	if (mp_irq->irqtype != m->irqtype)
 		return 5;
-	if (mp_irq->srcbusirq != m->srcbusirq)
+	if (mp_irq->irqflag != m->irqflag)
 		return 6;
-	if (mp_irq->dstirq != m->dstirq)
+	if (mp_irq->srcbusirq != m->srcbusirq)
 		return 7;
 
 	return 0;
@@ -195,9 +195,45 @@ static void __init MP_intsrc_info(struct
 
 	print_MP_intsrc_info(m);
 
+	/*
+	 *  All BUS, and IOAPIC entries are processed already
+	 */
+
+	/* check if dstapic is right */
+	for (i = 0; i < nr_ioapics; i++) {
+		if (mp_ioapics[i].apicid == m->dstapic)
+			break;
+	}
+	if (i == nr_ioapics) {
+		apic_printk(APIC_VERBOSE, "intsrc with wrong apic id is skipped\n");
+		return;
+	}
+
 	for (i = 0; i < mp_irq_entries; i++) {
-		if (!mp_irq_mpc_intsrc_cmp(&mp_irqs[i], m))
+		int ret = mp_irq_mpc_intsrc_cmp(&mp_irqs[i], m);
+
+		/* duplicated entries ? */
+		if (!ret) {
+			apic_printk(APIC_VERBOSE, "Duplicated intsrc is skipped\n");
 			return;
+		}
+
+		/* same apic/pin, but different bus */
+		if (ret == 3) {
+			/* overwrite wrong legacy one */
+			if (test_bit(mp_irqs[i].srcbus, mp_bus_not_pci) &&
+			    !test_bit(m->srcbus, mp_bus_not_pci)) {
+				apic_printk(APIC_VERBOSE, "Wrong legacy entry with same apic/pin is removed\n");
+				assign_to_mp_irq(m, &mp_irqs[i]);
+				return;
+			}
+			/* dump this legacy one */
+			if (!test_bit(mp_irqs[i].srcbus, mp_bus_not_pci) &&
+			    test_bit(m->srcbus, mp_bus_not_pci)) {
+				apic_printk(APIC_VERBOSE, "Wrong legacy entry is skipped\n");
+				return;
+			}
+		}
 	}
 
 	assign_to_mp_irq(m, &mp_irqs[mp_irq_entries]);
@@ -280,8 +316,8 @@ static int __init smp_read_mpc(struct mp
 	char str[16];
 	char oem[10];
 
-	int count = sizeof(*mpc);
-	unsigned char *mpt = ((unsigned char *)mpc) + count;
+	int count;
+	unsigned char *mpt;
 
 	if (!smp_check_mpc(mpc, oem, str))
 		return 0;
@@ -305,8 +341,9 @@ static int __init smp_read_mpc(struct mp
 	/*
 	 *      Now process the configuration blocks.
 	 */
+	count = sizeof(*mpc);
+	mpt = ((unsigned char *)mpc) + count;
 	x86_init.mpparse.mpc_record(0);
-
 	while (count < mpc->length) {
 		switch (*mpt) {
 		case MP_PROCESSOR:
@@ -324,7 +361,7 @@ static int __init smp_read_mpc(struct mp
 			skip_entry(&mpt, &count, sizeof(struct mpc_ioapic));
 			break;
 		case MP_INTSRC:
-			MP_intsrc_info((struct mpc_intsrc *)mpt);
+			/* check that next pass */
 			skip_entry(&mpt, &count, sizeof(struct mpc_intsrc));
 			break;
 		case MP_LINTSRC:
@@ -337,6 +374,35 @@ static int __init smp_read_mpc(struct mp
 			count = mpc->length;
 			break;
 		}
+		x86_init.mpparse.mpc_record(1);
+	}
+
+	/* second pass for INTSRC */
+	count = sizeof(*mpc);
+	mpt = ((unsigned char *)mpc) + count;
+	x86_init.mpparse.mpc_record(0);
+	while (count < mpc->length) {
+		switch (*mpt) {
+		case MP_PROCESSOR:
+			skip_entry(&mpt, &count, sizeof(struct mpc_cpu));
+			break;
+		case MP_BUS:
+			skip_entry(&mpt, &count, sizeof(struct mpc_bus));
+			break;
+		case MP_IOAPIC:
+			skip_entry(&mpt, &count, sizeof(struct mpc_ioapic));
+			break;
+		case MP_INTSRC:
+			MP_intsrc_info((struct mpc_intsrc *)mpt);
+			skip_entry(&mpt, &count, sizeof(struct mpc_intsrc));
+			break;
+		case MP_LINTSRC:
+			skip_entry(&mpt, &count, sizeof(struct mpc_lintsrc));
+			break;
+		default:
+			count = mpc->length;
+			break;
+		}
 		x86_init.mpparse.mpc_record(1);
 	}