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 68e4eb53a48bb4186fe79d0de791cc919f99b7f5..73539c64ede3fe14bc88db26de5ac755f5bb080f 100644 (file)
--- a/xen/arch/x86/smpboot.c
+++ b/xen/arch/x86/smpboot.c
@@ -899,7 +899,9 @@ 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 )
+    if ( (acpi_id >= MAX_MADT_ENTRIES) ||
+         (apic_id >= MAX_APICS) ||
+         (pxm >= 256) )
         return -EINVAL;
 
     if ( !cpu_hotplug_begin() )