Ping.
On Fri, Aug 28, 2015 at 9:51 PM, Pavel Boldin <pboldin at mirantis.com> wrote:
> * Move ioctl `EVENTFD_COPY' code to a separate function
> * Remove extra #includes
> * Introduce function fget_from_files
> * Fix ioctl return values
>
> Signed-off-by: Pavel Boldin <pboldin at mirantis.com>
> ---
> lib/librte_vhost/eventfd_link/eventfd_link.c | 188
> +++++++++++++++------------
> 1 file changed, 103 insertions(+), 85 deletions(-)
>
> diff --git a/lib/librte_vhost/eventfd_link/eventfd_link.c
> b/lib/librte_vhost/eventfd_link/eventfd_link.c
> index 62c45c8..5ba1068 100644
> --- a/lib/librte_vhost/eventfd_link/eventfd_link.c
> +++ b/lib/librte_vhost/eventfd_link/eventfd_link.c
> @@ -22,18 +22,11 @@
> * Intel Corporation
> */
>
> -#include <linux/eventfd.h>
> #include <linux/miscdevice.h>
> #include <linux/module.h>
> -#include <linux/moduleparam.h>
> -#include <linux/rcupdate.h>
> #include <linux/file.h>
> -#include <linux/slab.h>
> -#include <linux/fs.h>
> -#include <linux/mmu_context.h>
> -#include <linux/sched.h>
> -#include <asm/mmu_context.h>
> #include <linux/fdtable.h>
> +#include <linux/syscalls.h>
>
> #include "eventfd_link.h"
>
> @@ -65,9 +58,26 @@ put_files_struct(struct files_struct *files)
> BUG();
> }
>
> +static struct file *
> +fget_from_files(struct files_struct *files, unsigned fd)
> +{
> + struct file *file;
> +
> + rcu_read_lock();
> + file = fcheck_files(files, fd);
> + if (file)
> + {
> + if (file->f_mode & FMODE_PATH
> + || !atomic_long_inc_not_zero(&file->f_count))
> + file = NULL;
> + }
> + rcu_read_unlock();
> +
> + return file;
> +}
>
> static long
> -eventfd_link_ioctl(struct file *f, unsigned int ioctl, unsigned long arg)
> +eventfd_link_ioctl_copy(unsigned long arg)
> {
> void __user *argp = (void __user *) arg;
> struct task_struct *task_target = NULL;
> @@ -75,91 +85,99 @@ eventfd_link_ioctl(struct file *f, unsigned int ioctl,
> unsigned long arg)
> struct files_struct *files;
> struct fdtable *fdt;
> struct eventfd_copy eventfd_copy;
> + long ret = -EFAULT;
>
> - switch (ioctl) {
> - case EVENTFD_COPY:
> - if (copy_from_user(&eventfd_copy, argp,
> - sizeof(struct eventfd_copy)))
> - return -EFAULT;
> -
> - /*
> - * Find the task struct for the target pid
> - */
> - task_target =
> - pid_task(find_vpid(eventfd_copy.target_pid),
> PIDTYPE_PID);
> - if (task_target == NULL) {
> - pr_debug("Failed to get mem ctx for target pid\n");
> - return -EFAULT;
> - }
> -
> - files = get_files_struct(current);
> - if (files == NULL) {
> - pr_debug("Failed to get files struct\n");
> - return -EFAULT;
> - }
> -
> - rcu_read_lock();
> - file = fcheck_files(files, eventfd_copy.source_fd);
> - if (file) {
> - if (file->f_mode & FMODE_PATH ||
> - !atomic_long_inc_not_zero(&file->f_count))
> - file = NULL;
> - }
> - rcu_read_unlock();
> - put_files_struct(files);
> + if (copy_from_user(&eventfd_copy, argp, sizeof(struct
> eventfd_copy)))
> + goto out;
> +
> + /*
> + * Find the task struct for the target pid
> + */
> + ret = -ESRCH;
> +
> + task_target =
> + get_pid_task(find_vpid(eventfd_copy.target_pid),
> PIDTYPE_PID);
> + if (task_target == NULL) {
> + pr_info("Unable to find pid %d\n",
> eventfd_copy.target_pid);
> + goto out;
> + }
> +
> + ret = -ESTALE;
> + files = get_files_struct(current);
> + if (files == NULL) {
> + pr_info("Failed to get current files struct\n");
> + goto out_task;
> + }
>
> - if (file == NULL) {
> - pr_debug("Failed to get file from source pid\n");
> - return 0;
> - }
> -
> - /*
> - * Release the existing eventfd in the source process
> - */
> - spin_lock(&files->file_lock);
> - fput(file);
> - filp_close(file, files);
> - fdt = files_fdtable(files);
> - fdt->fd[eventfd_copy.source_fd] = NULL;
> - spin_unlock(&files->file_lock);
> -
> - /*
> - * Find the file struct associated with the target fd.
> - */
> -
> - files = get_files_struct(task_target);
> - if (files == NULL) {
> - pr_debug("Failed to get files struct\n");
> - return -EFAULT;
> - }
> -
> - rcu_read_lock();
> - file = fcheck_files(files, eventfd_copy.target_fd);
> - if (file) {
> - if (file->f_mode & FMODE_PATH ||
> - !atomic_long_inc_not_zero(&file->f_count))
> - file = NULL;
> - }
> - rcu_read_unlock();
> + ret = -EBADF;
> + file = fget_from_files(files, eventfd_copy.source_fd);
> +
> + if (file == NULL) {
> + pr_info("Failed to get fd %d from source\n",
> + eventfd_copy.source_fd);
> put_files_struct(files);
> + goto out_task;
> + }
> +
> + /*
> + * Release the existing eventfd in the source process
> + */
> + spin_lock(&files->file_lock);
> + fput(file);
> + filp_close(file, files);
> + fdt = files_fdtable(files);
> + fdt->fd[eventfd_copy.source_fd] = NULL;
> + spin_unlock(&files->file_lock);
> +
> + put_files_struct(files);
> +
> + /*
> + * Find the file struct associated with the target fd.
> + */
> +
> + 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_copy.target_fd);
> + put_files_struct(files);
> +
> + if (file == NULL) {
> + pr_info("Failed to get fd %d from target\n",
> + eventfd_copy.target_fd);
> + goto out_task;
> + }
>
> - if (file == NULL) {
> - pr_debug("Failed to get file from target pid\n");
> - return 0;
> - }
> + /*
> + * Install the file struct from the target process into the
> + * file desciptor of the source process,
> + */
>
> - /*
> - * Install the file struct from the target process into the
> - * file desciptor of the source process,
> - */
> + fd_install(eventfd_copy.source_fd, file);
> + ret = 0;
>
> - fd_install(eventfd_copy.source_fd, file);
> +out_task:
> + put_task_struct(task_target);
> +out:
> + return ret;
> +}
>
> - return 0;
> +static long
> +eventfd_link_ioctl(struct file *f, unsigned int ioctl, unsigned long arg)
> +{
> + long ret = -ENOIOCTLCMD;
>
> - default:
> - return -ENOIOCTLCMD;
> + switch (ioctl) {
> + case EVENTFD_COPY:
> + ret = eventfd_link_ioctl_copy(arg);
> + break;
> }
> +
> + return ret;
> }
>
> static const struct file_operations eventfd_link_fops = {
> --
> 1.9.1
>
>
