x86: Fix argument checking in (privileged) function cpu_add().

Thanks to John McDermott <john.mcdermott@nrl.navy.mil> for spotting.

Signed-off-by: Keir Fraser <keir@xen.org>
xen-unstable changeset:   23505:5a557fda70a9
xen-unstable date:        Fri Jun 10 08:08:44 2011 +0100

diff --git a/xen/arch/x86/smpboot.c b/xen/arch/x86/smpboot.c
index b0b9f52d65a6f519eb39a06204b4e30069b5a255..6ad01f822b3d4f5fbd54b5896d9a2330578b8e05 100644 (file)
--- a/xen/arch/x86/smpboot.c
+++ b/xen/arch/x86/smpboot.c
@@ -1477,8 +1477,9 @@ int cpu_add(uint32_t apic_id, uint32_t acpi_id, uint32_t pxm)
        dprintk(XENLOG_DEBUG, "cpu_add apic_id %x acpi_id %x pxm %x\n",
                apic_id, acpi_id, pxm);
 
-       if ( acpi_id > MAX_MADT_ENTRIES || apic_id > MAX_APICS || pxm > 256 )
-               return -EINVAL;
+       if ( (acpi_id >= MAX_MADT_ENTRIES) ||
+            (apic_id >= MAX_APICS) ||
+            (pxm >= 256) )
 
        /* Detect if the cpu has been added before */
        if ( x86_acpiid_to_apicid[acpi_id] != 0xff)