diff options
| author | Ben Hutchings <bhutchings@solarflare.com> | 2008-11-05 12:04:46 +0000 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-11-06 07:23:21 +0100 |
| commit | c78d0cf2925bffae8a6f00e7d9b8e971b0392edd (patch) | |
| tree | 5a7560368e55bd55b6a40ec1a0c36e59936a4e01 | |
| parent | e4ab1b3cbb8042f1653471c6333931134105d455 (diff) | |
x86: don't allow nr_irqs > NR_IRQS
Impact: fix boot hang on 32-bit systems with more than 224 IO-APIC pins
On some 32-bit systems with a lot of IO-APICs probe_nr_irqs() can
return a value larger than NR_IRQS. This will lead to probe_irq_on()
overrunning the irq_desc array.
I hit this when running net-next-2.6 (close to 2.6.28-rc3) on a
Supermicro dual Xeon system. NR_IRQS is 224 but probe_nr_irqs() detects
5 IOAPICs and returns 240. Here are the log messages:
Tue Nov 4 16:53:47 2008 ACPI: IOAPIC (id[0x01] address[0xfec00000] gsi_base[0])
Tue Nov 4 16:53:47 2008 IOAPIC[0]: apic_id 1, version 32, address 0xfec00000, GSI 0-23
Tue Nov 4 16:53:47 2008 ACPI: IOAPIC (id[0x02] address[0xfec81000] gsi_base[24])
Tue Nov 4 16:53:47 2008 IOAPIC[1]: apic_id 2, version 32, address 0xfec81000, GSI 24-47
Tue Nov 4 16:53:47 2008 ACPI: IOAPIC (id[0x03] address[0xfec81400] gsi_base[48])
Tue Nov 4 16:53:47 2008 IOAPIC[2]: apic_id 3, version 32, address 0xfec81400, GSI 48-71
Tue Nov 4 16:53:47 2008 ACPI: IOAPIC (id[0x04] address[0xfec82000] gsi_base[72])
Tue Nov 4 16:53:47 2008 IOAPIC[3]: apic_id 4, version 32, address 0xfec82000, GSI 72-95
Tue Nov 4 16:53:47 2008 ACPI: IOAPIC (id[0x05] address[0xfec82400] gsi_base[96])
Tue Nov 4 16:53:47 2008 IOAPIC[4]: apic_id 5, version 32, address 0xfec82400, GSI 96-119
Tue Nov 4 16:53:47 2008 ACPI: INT_SRC_OVR (bus 0 bus_irq 0 global_irq 2 high edge)
Tue Nov 4 16:53:47 2008 ACPI: INT_SRC_OVR (bus 0 bus_irq 9 global_irq 9 high level)
Tue Nov 4 16:53:47 2008 Enabling APIC mode: Flat. Using 5 I/O APICs
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Acked-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
| -rw-r--r-- | arch/x86/kernel/io_apic.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/x86/kernel/io_apic.c b/arch/x86/kernel/io_apic.c index b764d7429c6..7a3f2028e2e 100644 --- a/arch/x86/kernel/io_apic.c +++ b/arch/x86/kernel/io_apic.c @@ -3611,6 +3611,8 @@ int __init probe_nr_irqs(void) /* something wrong ? */ if (nr < nr_min) nr = nr_min; + if (WARN_ON(nr > NR_IRQS)) + nr = NR_IRQS; return nr; } |