[tip:x86/urgent] x86: Handle overlapping mptables

From: tip-bot for Andi Kleen
Date: Thu Apr 01 2010 - 17:13:28 EST

Commit-ID: 909fc87b32b3b9e3f0b87dcc5d98319c41900c58
Gitweb: http://git.kernel.org/tip/909fc87b32b3b9e3f0b87dcc5d98319c41900c58
Author: Andi Kleen <andi@xxxxxxxxxxxxxx>
AuthorDate: Mon, 29 Mar 2010 09:41:11 +0200
Committer: H. Peter Anvin <hpa@xxxxxxxxx>
CommitDate: Thu, 1 Apr 2010 13:31:07 -0700

x86: Handle overlapping mptables

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@xxxxxxx>
Tested-by: Thomas Renninger <trenn@xxxxxxx>
Signed-off-by: Andi Kleen <ak@xxxxxxxxxxxxxxx>
LKML-Reference: <20100329074111.GA22821@xxxxxxxxxxxxxxx>
Signed-off-by: H. Peter Anvin <hpa@xxxxxxxxx>
Cc: <stable@xxxxxxxxxx>
arch/x86/kernel/mpparse.c | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/mpparse.c b/arch/x86/kernel/mpparse.c
index a2c1edd..e81030f 100644
--- a/arch/x86/kernel/mpparse.c
+++ b/arch/x86/kernel/mpparse.c
@@ -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)

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