From: Vitaly Kuznetsov <vkuznets@redhat.com>
Date: Wed, 7 Dec 2016 09:16:25 +0000 (-0800)
Subject: hv: allocate synic pages for all present CPUs
X-Git-Tag: v3.12.72~27
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=3ee3990aefa1860fca0c00bf1a03ebaab993550e;p=thirdparty%2Fkernel%2Fstable.git

hv: allocate synic pages for all present CPUs

commit 421b8f20d3c381b215f988b42428f56fc3b82405 upstream.

It may happen that not all CPUs are online when we do hv_synic_alloc() and
in case more CPUs come online later we may try accessing these allocated
structures.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---

diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c
index 88f4096fa078d..3fdb9af087054 100644
--- a/drivers/hv/hv.c
+++ b/drivers/hv/hv.c
@@ -271,7 +271,7 @@ int hv_synic_alloc(void)
 	size_t size = sizeof(struct tasklet_struct);
 	int cpu;
 
-	for_each_online_cpu(cpu) {
+	for_each_present_cpu(cpu) {
 		hv_context.event_dpc[cpu] = kmalloc(size, GFP_ATOMIC);
 		if (hv_context.event_dpc[cpu] == NULL) {
 			pr_err("Unable to allocate event dpc\n");
@@ -314,7 +314,7 @@ void hv_synic_free(void)
 {
 	int cpu;
 
-	for_each_online_cpu(cpu)
+	for_each_present_cpu(cpu)
 		hv_synic_free_cpu(cpu);
 }