[patch 36/54] acpi: fix potential call to a freed memory section.

Chris Wright
2007-06-08T07:48:19Z

[-- Attachment #1: acpi-fix-potential-call-to-a-freed-memory-section.patch --]
[-- Type: text/plain, Size: 2323 bytes --]

-stable review patch. If anyone has any objections, please let us know.
---------------------

From: Aaron Durbin <adurbin@google.com>

Strip __cpuinit[data] from Node <-> PXM routines and supporting data
structures. Also make pxm_to_node_map and node_to_pxm_map local to the
numa acpi module.

This fixes a bug triggered by the following conditions:
- boot on a machine with a SLIT table defined
- kernel is configured w/ CONFIG_HOTPLUG_CPU=n
- cat /sys/devices/system/node/node*/distance
This will cause an oops by calling into a freed memory section.

In particular, on x86_64, __node_distance calls node_to_pxm().

Signed-off-by: Aaron Durbin <adurbin@google.com>
Cc: Len Brown <lenb@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>

---
drivers/acpi/numa.c | 8 ++++----
include/acpi/acpi_numa.h | 7 ++-----
2 files changed, 6 insertions(+), 9 deletions(-)

--- linux-2.6.21.4.orig/drivers/acpi/numa.c
+++ linux-2.6.21.4/drivers/acpi/numa.c
@@ -40,19 +40,19 @@ static nodemask_t nodes_found_map = NODE
#define NID_INVAL -1

/* maps to convert between proximity domain and logical node ID */
-int __cpuinitdata pxm_to_node_map[MAX_PXM_DOMAINS]
+static int pxm_to_node_map[MAX_PXM_DOMAINS]
= { [0 ... MAX_PXM_DOMAINS - 1] = NID_INVAL };
-int __cpuinitdata node_to_pxm_map[MAX_NUMNODES]
+static int node_to_pxm_map[MAX_NUMNODES]
= { [0 ... MAX_NUMNODES - 1] = PXM_INVAL };

-int __cpuinit pxm_to_node(int pxm)
+int pxm_to_node(int pxm)
{
if (pxm < 0)
return NID_INVAL;
return pxm_to_node_map[pxm];
}

-int __cpuinit node_to_pxm(int node)
+int node_to_pxm(int node)
{
if (node < 0)
return PXM_INVAL;
--- linux-2.6.21.4.orig/include/acpi/acpi_numa.h
+++ linux-2.6.21.4/include/acpi/acpi_numa.h
@@ -11,11 +11,8 @@
#define MAX_PXM_DOMAINS (256) /* Old pxm spec is defined 8 bit */
#endif

-extern int __cpuinitdata pxm_to_node_map[MAX_PXM_DOMAINS];
-extern int __cpuinitdata node_to_pxm_map[MAX_NUMNODES];
-
-extern int __cpuinit pxm_to_node(int);
-extern int __cpuinit node_to_pxm(int);
+extern int pxm_to_node(int);
+extern int node_to_pxm(int);
extern int __cpuinit acpi_map_pxm_to_node(int);
extern void __cpuinit acpi_unmap_pxm_to_node(int);

--