linux-kernel - [PATCH] x86 microcode: don't check the size

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Message-Id: <1157597227.2782.55.camel@sli10-desk.sh.intel.com>
Date:	Thu, 07 Sep 2006 10:47:07 +0800
From:	Shaohua Li <shaohua.li@...el.com>
To:	lkml <linux-kernel@...r.kernel.org>
Cc:	Andrew Morton <akpm@...l.org>, Tigran Aivazian <tigran@...itas.com>
Subject: [PATCH] x86 microcode: don't check the size

IA32 manual says if micorcode update's size is 0, then the size is
default size (2048 bytes). But this doesn't suggest all microcode
update's size should be above 2048 bytes to me. We actually had a
microcode update whose size is 1024 bytes. The patch just removed the
check.

Signed-off-by: Shaohua Li <shaohua.li@...el.com>

---
 work/src/linux-2.6.18-rc5-mm1/arch/i386/kernel/microcode.c |   14 ++-----------
 1 files changed, 3 insertions(+), 11 deletions(-)

Index: root/work/src/linux-2.6.18-rc5-mm1/arch/i386/kernel/microcode.c
===================================================================
--- root.orig/work/src/linux-2.6.18-rc5-mm1/arch/i386/kernel/microcode.c	2006-09-06 06:51:03.000000000 +0800
+++ root/work/src/linux-2.6.18-rc5-mm1/arch/i386/kernel/microcode.c	2006-09-06 08:20:35.000000000 +0800
@@ -187,8 +187,7 @@ static int microcode_sanity_check(void *
 
 	total_size = get_totalsize(mc_header);
 	data_size = get_datasize(mc_header);
-	if ((data_size + MC_HEADER_SIZE > total_size)
-		|| (data_size < DEFAULT_UCODE_DATASIZE)) {
+	if (data_size + MC_HEADER_SIZE > total_size) {
 		printk(KERN_ERR "microcode: error! "
 			"Bad data size in microcode data file\n");
 		return -EINVAL;
@@ -365,8 +364,7 @@ static long get_next_ucode(void **mc, lo
 		return -EFAULT;
 	}
 	total_size = get_totalsize(&mc_header);
-	if ((offset + total_size > user_buffer_size)
-		|| (total_size < DEFAULT_UCODE_TOTALSIZE)) {
+	if (offset + total_size > user_buffer_size) {
 		printk(KERN_ERR "microcode: error! Bad total size in microcode "
 				"data file\n");
 		return -EINVAL;
@@ -432,11 +430,6 @@ static ssize_t microcode_write (struct f
 {
 	ssize_t ret;
 
-	if (len < DEFAULT_UCODE_TOTALSIZE) {
-		printk(KERN_ERR "microcode: not enough data\n"); 
-		return -EINVAL;
-	}
-
 	if ((len >> PAGE_SHIFT) > num_physpages) {
 		printk(KERN_ERR "microcode: too much data (max %ld pages)\n", num_physpages);
 		return -EINVAL;
@@ -508,8 +501,7 @@ static long get_next_ucode_from_buffer(v
 	mc_header = (microcode_header_t *)(buf + offset);
 	total_size = get_totalsize(mc_header);
 
-	if ((offset + total_size > size)
-		|| (total_size < DEFAULT_UCODE_TOTALSIZE)) {
+	if (offset + total_size > size) {
 		printk(KERN_ERR "microcode: error! Bad data in microcode data file\n");
 		return -EINVAL;
 	}
-
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