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Commit 5cf6c541 authored by Dave Jones's avatar Dave Jones Committed by Linus Torvalds
Browse files

[PATCH] x86 microcode driver vs hotplug CPUs. 



This driver loops over 'num_online_cpus', but it doesn't account for holes
in the online map created by offlined cpus, and assumes that the cpu
numbers stay linear.

Signed-off-by: default avatarDave Jones <davej@redhat.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent ec72070b

arch/i386/kernel/microcode.c

+9 −6
Original line number Diff line number Diff line
@@ -74,6 +74,7 @@ 
#include <linux/kernel.h>

#include <linux/init.h>

#include <linux/sched.h>

#include <linux/cpumask.h>

#include <linux/module.h>

#include <linux/slab.h>

#include <linux/vmalloc.h>
@@ -251,7 +252,7 @@ static int find_matching_ucodes (void) 
			goto out;

		}



		for (cpu_num = 0; cpu_num < num_online_cpus(); cpu_num++) {

		for_each_online_cpu(cpu_num) {

			struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;

			if (uci->err != MC_NOTFOUND) /* already found a match or not an online cpu*/

				continue;
@@ -293,7 +294,7 @@ static int find_matching_ucodes (void) 
					error = -EFAULT;

					goto out;

				}

				for (cpu_num = 0; cpu_num < num_online_cpus(); cpu_num++) {

				for_each_online_cpu(cpu_num) {

					struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;

					if (uci->err != MC_NOTFOUND) /* already found a match or not an online cpu*/

						continue;
@@ -304,7 +305,9 @@ static int find_matching_ucodes (void) 
			}

		}

		/* now check if any cpu has matched */

		for (cpu_num = 0, allocated_flag = 0, sum = 0; cpu_num < num_online_cpus(); cpu_num++) {

		allocated_flag = 0;

		sum = 0;

		for_each_online_cpu(cpu_num) {

			if (ucode_cpu_info[cpu_num].err == MC_MARKED) { 

				struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;

				if (!allocated_flag) {
@@ -415,12 +418,12 @@ static int do_microcode_update (void) 
	}



out_free:

	for (i = 0; i < num_online_cpus(); i++) {

	for_each_online_cpu(i) {

		if (ucode_cpu_info[i].mc) {

			int j;

			void *tmp = ucode_cpu_info[i].mc;

			vfree(tmp);

			for (j = i; j < num_online_cpus(); j++) {

			for_each_online_cpu(j) {

				if (ucode_cpu_info[j].mc == tmp)

					ucode_cpu_info[j].mc = NULL;

			}