Messages in this thread Patch in this message | | | From | Wen Yang <> | Subject | [PATCH] pvcalls-front: Use GFP_ATOMIC under spin_lock | Date | Thu, 29 Nov 2018 20:01:01 +0800 |
| |
The problem is that we call this with a spin lock held. The call tree is: pvcalls_front_accept() holds bedata->socket_lock. -> create_active() -> __get_free_pages() uses GFP_KERNEL
The create_active() function is only called from pvcalls_front_accept() with a spin_lock held, The allocation is not allowed to sleep and GFP_KERNEL is not sufficient, it has to be ATOMIC.
This issue was detected by using the Coccinelle software.
Signed-off-by: Wen Yang <wen.yang99@zte.com.cn> CC: Julia Lawall <julia.lawall@lip6.fr> CC: Boris Ostrovsky <boris.ostrovsky@oracle.com> CC: Juergen Gross <jgross@suse.com> CC: Stefano Stabellini <sstabellini@kernel.org> CC: xen-devel@lists.xenproject.org CC: linux-kernel@vger.kernel.org --- drivers/xen/pvcalls-front.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/xen/pvcalls-front.c b/drivers/xen/pvcalls-front.c index 2f11ca72a281..f2bbc06a0f7f 100644 --- a/drivers/xen/pvcalls-front.c +++ b/drivers/xen/pvcalls-front.c @@ -344,11 +344,11 @@ static int create_active(struct sock_mapping *map, int *evtchn) init_waitqueue_head(&map->active.inflight_conn_req); map->active.ring = (struct pvcalls_data_intf *) - __get_free_page(GFP_KERNEL | __GFP_ZERO); + __get_free_page(GFP_ATOMIC | __GFP_ZERO); if (map->active.ring == NULL) goto out_error; map->active.ring->ring_order = PVCALLS_RING_ORDER; - bytes = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, + bytes = (void *)__get_free_pages(GFP_ATOMIC | __GFP_ZERO, PVCALLS_RING_ORDER); if (bytes == NULL) goto out_error; -- 2.19.1
| |