Patch "hv: allocate synic pages for all present CPUs" has been added to the 4.9-stable tree

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

    hv: allocate synic pages for all present CPUs

to the 4.9-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     hv-allocate-synic-pages-for-all-present-cpus.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 421b8f20d3c381b215f988b42428f56fc3b82405 Mon Sep 17 00:00:00 2001
From: Vitaly Kuznetsov <vkuznets@redhat.com>
Date: Wed, 7 Dec 2016 01:16:25 -0800
Subject: hv: allocate synic pages for all present CPUs

From: Vitaly Kuznetsov <vkuznets@redhat.com>

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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/hv/hv.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/hv/hv.c
+++ b/drivers/hv/hv.c
@@ -411,7 +411,7 @@ int hv_synic_alloc(void)
 		goto err;
 	}
 
-	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");
@@ -482,7 +482,7 @@ void hv_synic_free(void)
 	int cpu;
 
 	kfree(hv_context.hv_numa_map);
-	for_each_online_cpu(cpu)
+	for_each_present_cpu(cpu)
 		hv_synic_free_cpu(cpu);
 }
 


Patches currently in stable-queue which might be from vkuznets@redhat.com are

queue-4.9/hv-init-percpu_list-in-hv_synic_alloc.patch
queue-4.9/drivers-hv-vmbus-raise-retry-wait-limits-in-vmbus_post_msg.patch
queue-4.9/hv-allocate-synic-pages-for-all-present-cpus.patch
queue-4.9/hv-don-t-reset-hv_context.tsc_page-on-crash.patch