vhost: add new eventfd copy ioctl

[dpdk.git] / lib / librte_vhost / eventfd_link / eventfd_link.c

diff --git a/lib/librte_vhost/eventfd_link/eventfd_link.c b/lib/librte_vhost/eventfd_link/eventfd_link.c
index 7cbebd4..c54a938 100644 (file)
--- a/lib/librte_vhost/eventfd_link/eventfd_link.c
+++ b/lib/librte_vhost/eventfd_link/eventfd_link.c
@@ -77,6 +77,64 @@ fget_from_files(struct files_struct *files, unsigned fd)
        return file;
 }
 
+static long
+eventfd_link_ioctl_copy2(unsigned long arg)
+{
+       void __user *argp = (void __user *) arg;
+       struct task_struct *task_target = NULL;
+       struct file *file;
+       struct files_struct *files;
+       struct eventfd_copy2 eventfd_copy2;
+       long ret = -EFAULT;
+
+       if (copy_from_user(&eventfd_copy2, argp, sizeof(struct eventfd_copy2)))
+               goto out;
+
+       /*
+        * Find the task struct for the target pid
+        */
+       ret = -ESRCH;
+
+       task_target =
+               get_pid_task(find_vpid(eventfd_copy2.pid), PIDTYPE_PID);
+       if (task_target == NULL) {
+               pr_info("Unable to find pid %d\n", eventfd_copy2.pid);
+               goto out;
+       }
+
+       ret = -ESTALE;
+       files = get_files_struct(task_target);
+       if (files == NULL) {
+               pr_info("Failed to get target files struct\n");
+               goto out_task;
+       }
+
+       ret = -EBADF;
+       file = fget_from_files(files, eventfd_copy2.fd);
+       put_files_struct(files);
+
+       if (file == NULL) {
+               pr_info("Failed to get fd %d from target\n", eventfd_copy2.fd);
+               goto out_task;
+       }
+
+       /*
+        * Install the file struct from the target process into the
+        * newly allocated file desciptor of the source process.
+        */
+       ret = get_unused_fd_flags(eventfd_copy2.flags);
+       if (ret < 0) {
+               fput(file);
+               goto out_task;
+       }
+       fd_install(ret, file);
+
+out_task:
+       put_task_struct(task_target);
+out:
+       return ret;
+}
+
 static long
 eventfd_link_ioctl_copy(unsigned long arg)
 {
@@ -176,6 +234,9 @@ eventfd_link_ioctl(struct file *f, unsigned int ioctl, unsigned long arg)
        case EVENTFD_COPY:
                ret = eventfd_link_ioctl_copy(arg);
                break;
+       case EVENTFD_COPY2:
+               ret = eventfd_link_ioctl_copy2(arg);
+               break;
        }
 
        return ret;