From: Shaohua Li <shaohua.li@intel.com>
Date: Mon, 20 Nov 2006 17:02:46 +0000 (-0500)
Subject: [PATCH] x86 microcode: don't check the size
X-Git-Tag: v2.6.18.5~10
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=44b3e3dc001b3aad89409a55f9ce2a83e047fb7d;p=thirdparty%2Fkernel%2Fstable.git

[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.

Backported to 2.6.18 by Daniel Drake.

Signed-off-by: Daniel Drake <dsd@gentoo.org>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
---

diff --git a/arch/i386/kernel/microcode.c b/arch/i386/kernel/microcode.c
index 40b44cc0d14b0..e5520eb870201 100644
--- a/arch/i386/kernel/microcode.c
+++ b/arch/i386/kernel/microcode.c
@@ -250,14 +250,14 @@ static int find_matching_ucodes (void)
 		}
 
 		total_size = get_totalsize(&mc_header);
-		if ((cursor + total_size > user_buffer_size) || (total_size < DEFAULT_UCODE_TOTALSIZE)) {
+		if (cursor + total_size > user_buffer_size) {
 			printk(KERN_ERR "microcode: error! Bad data in microcode data file\n");
 			error = -EINVAL;
 			goto out;
 		}
 
 		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 in microcode data file\n");
 			error = -EINVAL;
 			goto out;
@@ -460,11 +460,6 @@ static ssize_t microcode_write (struct file *file, const char __user *buf, size_
 {
 	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;