[PATCH 3.12 34/60] hv: allocate synic pages for all present CPUs

From: Jiri Slaby
Date: Tue Mar 14 2017 - 09:25:42 EST


From: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>

3.12-stable review patch. If anyone has any objections, please let me know.

===============

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@xxxxxxxxxx>
Signed-off-by: K. Y. Srinivasan <kys@xxxxxxxxxxxxx>
Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
---
drivers/hv/hv.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c
index 88f4096fa078..3fdb9af08705 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);
}

--
2.12.0