diff options
| -rw-r--r-- | drivers/xen/privcmd.c | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/drivers/xen/privcmd.c b/drivers/xen/privcmd.c index f4ba962de62b..9563650dfbaf 100644 --- a/drivers/xen/privcmd.c +++ b/drivers/xen/privcmd.c @@ -17,6 +17,7 @@ #include <linux/poll.h> #include <linux/sched.h> #include <linux/slab.h> +#include <linux/srcu.h> #include <linux/string.h> #include <linux/workqueue.h> #include <linux/errno.h> @@ -847,6 +848,7 @@ out: /* Irqfd support */ static struct workqueue_struct *irqfd_cleanup_wq; static DEFINE_SPINLOCK(irqfds_lock); +DEFINE_STATIC_SRCU(irqfds_srcu); static LIST_HEAD(irqfds_list); struct privcmd_kernel_irqfd { @@ -874,6 +876,9 @@ static void irqfd_shutdown(struct work_struct *work) container_of(work, struct privcmd_kernel_irqfd, shutdown); u64 cnt; + /* Make sure irqfd has been initialized in assign path */ + synchronize_srcu(&irqfds_srcu); + eventfd_ctx_remove_wait_queue(kirqfd->eventfd, &kirqfd->wait, &cnt); eventfd_ctx_put(kirqfd->eventfd); kfree(kirqfd); @@ -936,7 +941,7 @@ static int privcmd_irqfd_assign(struct privcmd_irqfd *irqfd) __poll_t events; struct fd f; void *dm_op; - int ret; + int ret, idx; kirqfd = kzalloc(sizeof(*kirqfd) + irqfd->size, GFP_KERNEL); if (!kirqfd) @@ -982,6 +987,7 @@ static int privcmd_irqfd_assign(struct privcmd_irqfd *irqfd) } } + idx = srcu_read_lock(&irqfds_srcu); list_add_tail(&kirqfd->list, &irqfds_list); spin_unlock_irqrestore(&irqfds_lock, flags); @@ -993,6 +999,8 @@ static int privcmd_irqfd_assign(struct privcmd_irqfd *irqfd) if (events & EPOLLIN) irqfd_inject(kirqfd); + srcu_read_unlock(&irqfds_srcu, idx); + /* * Do not drop the file until the kirqfd is fully initialized, otherwise * we might race against the EPOLLHUP. |