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From 7180de9a27ce433efc15bc1982b9a9e4ba3c48dc Mon Sep 17 00:00:00 2001
From: Jonas Gorski <jonas.gorski@gmail.com>
Date: Sat, 10 Nov 2012 02:04:58 +0100
Subject: [PATCH] MIPS: BCM63XX: fix nvram checksum calculation
The current checksum calculation code does nothing except checking that
the first byte of nvram is 0 without actually checking the checksum.
Implement the correct checksum calculation by calculating the crc32 with
the checksum field set to 0.
Signed-off-by: Jonas Gorski <jonas.gorski@gmail.com>
---
This patch depends on the previous nvram patch ("move nvram functions
into their own file").
arch/mips/bcm63xx/nvram.c | 23 +++++++++++++----------
1 files changed, 13 insertions(+), 10 deletions(-)
--- a/arch/mips/bcm63xx/nvram.c
+++ b/arch/mips/bcm63xx/nvram.c
@@ -11,6 +11,7 @@
#define pr_fmt(fmt) "bcm63xx_nvram: " fmt
#include <linux/init.h>
+#include <linux/crc32.h>
#include <linux/export.h>
#include <linux/kernel.h>
#include <linux/if_ether.h>
@@ -40,23 +41,25 @@ static int mac_addr_used;
int __init bcm63xx_nvram_init(void *addr)
{
unsigned int check_len;
- u8 *p;
- u32 val;
+ u32 crc, expected_crc;
/* extract nvram data */
memcpy(&nvram, addr, sizeof(nvram));
/* check checksum before using data */
- if (nvram.version <= 4)
- check_len = offsetof(struct bcm963xx_nvram, checksum_old);
- else
+ if (nvram.version <= 4) {
+ check_len = offsetof(struct bcm963xx_nvram, reserved3);
+ expected_crc = nvram.checksum_old;
+ nvram.checksum_old = 0;
+ } else {
check_len = sizeof(nvram);
- val = 0;
- p = (u8 *)&nvram;
+ expected_crc = nvram.checksum_high;
+ nvram.checksum_high = 0;
+ }
- while (check_len--)
- val += *p;
- if (val)
+ crc = crc32_le(~0, (u8 *)&nvram, check_len);
+
+ if (crc != expected_crc)
return -EINVAL;
return 0;
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