Patch "hv: init percpu_list in hv_synic_alloc()" has been added to the 4.4-stable tree

[<gregkh@linuxfoundation.org>]

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

    hv: init percpu_list in hv_synic_alloc()

to the 4.4-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-init-percpu_list-in-hv_synic_alloc.patch
and it can be found in the queue-4.4 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 3c7630d35009e6635e5b58d62de554fd5b6db5df Mon Sep 17 00:00:00 2001
From: Vitaly Kuznetsov <vkuznets@redhat.com>
Date: Wed, 7 Dec 2016 01:16:26 -0800
Subject: hv: init percpu_list in hv_synic_alloc()

From: Vitaly Kuznetsov <vkuznets@redhat.com>

commit 3c7630d35009e6635e5b58d62de554fd5b6db5df upstream.

Initializing hv_context.percpu_list in hv_synic_alloc() helps to prevent a
crash in percpu_channel_enq() when not all CPUs were online during
initialization and it naturally belongs there.

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
@@ -461,6 +461,8 @@ int hv_synic_alloc(void)
 			pr_err("Unable to allocate post msg page\n");
 			goto err;
 		}
+
+		INIT_LIST_HEAD(&hv_context.percpu_list[cpu]);
 	}
 
 	return 0;
@@ -555,8 +557,6 @@ void hv_synic_init(void *arg)
 	rdmsrl(HV_X64_MSR_VP_INDEX, vp_index);
 	hv_context.vp_index[cpu] = (u32)vp_index;
 
-	INIT_LIST_HEAD(&hv_context.percpu_list[cpu]);
-
 	/*
 	 * Register the per-cpu clockevent source.
 	 */


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

queue-4.4/hv-init-percpu_list-in-hv_synic_alloc.patch
queue-4.4/hv-allocate-synic-pages-for-all-present-cpus.patch