[tip:x86/mce] dmi: Avoid unaligned memory access in save_mem_devices()

From: tip-bot for Luck, Tony
Date: Sun Nov 03 2013 - 05:19:53 EST


Commit-ID: 0841c04d65937ad2808f59c43cb54a92473c8f0e
Gitweb: http://git.kernel.org/tip/0841c04d65937ad2808f59c43cb54a92473c8f0e
Author: Luck, Tony <tony.luck@xxxxxxxxx>
AuthorDate: Fri, 1 Nov 2013 13:59:52 -0700
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Sun, 3 Nov 2013 10:40:12 +0100

dmi: Avoid unaligned memory access in save_mem_devices()

Firmware is not required to maintain alignment of SMBIOS
entries, so we should take care accessing fields within these
structures. Use "get_unaligned()" to avoid problems.

[ Found on ia64 (which grumbles about unaligned access) ]

Signed-off-by: Tony Luck <tony.luck@xxxxxxxxx>
Cc: Chen Gong <gong.chen@xxxxxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/27d82dbff5be1025bf18ab88498632d36c2fcf3c.1383331440.git.tony.luck@xxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
drivers/firmware/dmi_scan.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/firmware/dmi_scan.c b/drivers/firmware/dmi_scan.c
index 59579a7..c7e81ff 100644
--- a/drivers/firmware/dmi_scan.c
+++ b/drivers/firmware/dmi_scan.c
@@ -8,6 +8,7 @@
#include <linux/bootmem.h>
#include <linux/random.h>
#include <asm/dmi.h>
+#include <asm/unaligned.h>

/*
* DMI stands for "Desktop Management Interface". It is part
@@ -347,7 +348,7 @@ static void __init save_mem_devices(const struct dmi_header *dm, void *v)
pr_warn(FW_BUG "Too many DIMM entries in SMBIOS table\n");
return;
}
- dmi_memdev[nr].handle = dm->handle;
+ dmi_memdev[nr].handle = get_unaligned(&dm->handle);
dmi_memdev[nr].device = dmi_string(dm, d[0x10]);
dmi_memdev[nr].bank = dmi_string(dm, d[0x11]);
nr++;
--
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