[PATCH] [REGRESSION 2.6.33] x86: Handle overlapping mptables

[PATCH] [REGRESSION 2.6.33] x86: Handle overlapping mptables

[Andi Kleen]

[REGRESSION] 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@suse.de>
Tested-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Andi Kleen <ak@linux.intel.com>

---
 arch/x86/kernel/cpu/perfctr-watchdog.c |   10 ++++++++--
 arch/x86/kernel/mpparse.c              |    4 ++--
 2 files changed, 10 insertions(+), 4 deletions(-)

Index: linux-2.6.33-ak/arch/x86/kernel/mpparse.c
===================================================================
--- linux-2.6.33-ak.orig/arch/x86/kernel/mpparse.c
+++ linux-2.6.33-ak/arch/x86/kernel/mpparse.c
@@ -664,7 +664,7 @@ static void __init smp_reserve_memory(st
 {
 	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(unsign
 			       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);
 

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

[tip-bot for Andi Kleen]

Commit-ID:  909fc87b32b3b9e3f0b87dcc5d98319c41900c58
Gitweb:     http://git.kernel.org/tip/909fc87b32b3b9e3f0b87dcc5d98319c41900c58
Author:     Andi Kleen <andi@firstfloor.org>
AuthorDate: Mon, 29 Mar 2010 09:41:11 +0200
Committer:  H. Peter Anvin <hpa@zytor.com>
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@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 |    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)
 				smp_reserve_memory(mpf);