[PATCH 4.9 108/153] hv: allocate synic pages for all present CPUs

Greg Kroah-Hartman
2017-03-10T09:25:54Z

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);
}