x86: Handle overlapping mptables
Andi Kleen [Mon, 29 Mar 2010 07:41:11 +0000 (09:41 +0200)]
We found a system where the MP table MPC and MPF structures overlap.

That doesn't really matter because the mptable is not used anyways with ACPI,
but it leads to a panic in the early allocator due to the overlapping
reservations in 2.6.33.

Earlier kernels handled this without problems.

Simply change these reservations to reserve_early_overlap_ok to avoid
the panic.

Reported-by: Thomas Renninger <trenn@suse.de>
Tested-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
LKML-Reference: <20100329074111.GA22821@basil.fritz.box>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: <stable@kernel.org>

arch/x86/kernel/mpparse.c

index a2c1edd..e81030f 100644 (file)
@@ -664,7 +664,7 @@ static void __init smp_reserve_memory(struct mpf_intel *mpf)
 {
        unsigned long size = get_mpc_size(mpf->physptr);
 
-       reserve_early(mpf->physptr, mpf->physptr+size, "MP-table mpc");
+       reserve_early_overlap_ok(mpf->physptr, mpf->physptr+size, "MP-table mpc");
 }
 
 static int __init smp_scan_config(unsigned long base, unsigned long length)
@@ -693,7 +693,7 @@ static int __init smp_scan_config(unsigned long base, unsigned long length)
                               mpf, (u64)virt_to_phys(mpf));
 
                        mem = virt_to_phys(mpf);
-                       reserve_early(mem, mem + sizeof(*mpf), "MP-table mpf");
+                       reserve_early_overlap_ok(mem, mem + sizeof(*mpf), "MP-table mpf");
                        if (mpf->physptr)
                                smp_reserve_memory(mpf);