[v5,5/5] staging/android: add flags member to sync ioctl structs

Submitted by Gustavo Padovan on March 1, 2016, 1:13 p.m.

Details

Message ID 1456837981-31584-5-git-send-email-gustavo@padovan.org
State New
Headers show
Series "Series without cover letter" ( rev: 1 ) in DRI devel

Not browsing as part of any series.

Commit Message

Gustavo Padovan March 1, 2016, 1:13 p.m.
From: Gustavo Padovan <gustavo.padovan@collabora.co.uk>

Play safe and add flags member to all structs. So we don't need to
break API or create new IOCTL in the future if new features that requires
flags arises.

v2: check if flags are valid (zero, in this case)

v3: return -EINVAL if flags are not zero'ed

Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
---
 drivers/staging/android/sync.c      | 8 ++++++++
 drivers/staging/android/uapi/sync.h | 6 ++++++
 2 files changed, 14 insertions(+)

Patch hide | download patch | download mbox

diff --git a/drivers/staging/android/sync.c b/drivers/staging/android/sync.c
index 3604e453..3c265ed 100644
--- a/drivers/staging/android/sync.c
+++ b/drivers/staging/android/sync.c
@@ -445,6 +445,11 @@  static long sync_file_ioctl_merge(struct sync_file *sync_file,
 		goto err_put_fd;
 	}
 
+	if (data.flags) {
+		err = -EINVAL;
+		goto err_put_fd;
+	}
+
 	fence2 = sync_file_fdget(data.fd2);
 	if (!fence2) {
 		err = -ENOENT;
@@ -504,6 +509,9 @@  static long sync_file_ioctl_fence_info(struct sync_file *sync_file,
 	if (copy_from_user(&in, (void __user *)arg, sizeof(in)))
 		return -EFAULT;
 
+	if (in.flags)
+		return -EINVAL;
+
 	info = kzalloc(sizeof(*info), GFP_KERNEL);
 	if (!info)
 		return -ENOMEM;
diff --git a/drivers/staging/android/uapi/sync.h b/drivers/staging/android/uapi/sync.h
index a122bb5..11e2d28 100644
--- a/drivers/staging/android/uapi/sync.h
+++ b/drivers/staging/android/uapi/sync.h
@@ -19,11 +19,13 @@ 
  * @fd2:	file descriptor of second fence
  * @name:	name of new fence
  * @fence:	returns the fd of the new fence to userspace
+ * @flags:	merge_data flags
  */
 struct sync_merge_data {
 	__s32	fd2;
 	char	name[32];
 	__s32	fence;
+	__u32	flags;
 };
 
 /**
@@ -31,12 +33,14 @@  struct sync_merge_data {
  * @obj_name:		name of parent sync_timeline
  * @driver_name:	name of driver implementing the parent
  * @status:		status of the fence 0:active 1:signaled <0:error
+ * @flags:		fence_info flags
  * @timestamp_ns:	timestamp of status change in nanoseconds
  */
 struct sync_fence_info {
 	char	obj_name[32];
 	char	driver_name[32];
 	__s32	status;
+	__u32	flags;
 	__u64	timestamp_ns;
 };
 
@@ -44,6 +48,7 @@  struct sync_fence_info {
  * struct sync_file_info - data returned from fence info ioctl
  * @name:	name of fence
  * @status:	status of fence. 1: signaled 0:active <0:error
+ * @flags:	sync_file_info flags
  * @num_fences	number of fences in the sync_file
  * @sync_fence_info: pointer to array of structs sync_fence_info with all
  *		 fences in the sync_file
@@ -51,6 +56,7 @@  struct sync_fence_info {
 struct sync_file_info {
 	char	name[32];
 	__s32	status;
+	__u32	flags;
 	__u32	num_fences;
 
 	__u64	sync_fence_info;

Comments

On 1 March 2016 at 13:13, Gustavo Padovan <gustavo@padovan.org> wrote:
> From: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
>
> Play safe and add flags member to all structs. So we don't need to
> break API or create new IOCTL in the future if new features that requires
> flags arises.
>
> v2: check if flags are valid (zero, in this case)
>
> v3: return -EINVAL if flags are not zero'ed
>
> Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
> ---
>  drivers/staging/android/sync.c      | 8 ++++++++
>  drivers/staging/android/uapi/sync.h | 6 ++++++
>  2 files changed, 14 insertions(+)
>
> diff --git a/drivers/staging/android/sync.c b/drivers/staging/android/sync.c
> index 3604e453..3c265ed 100644
> --- a/drivers/staging/android/sync.c
> +++ b/drivers/staging/android/sync.c
> @@ -445,6 +445,11 @@ static long sync_file_ioctl_merge(struct sync_file *sync_file,
>                 goto err_put_fd;
>         }
>
> +       if (data.flags) {
> +               err = -EINVAL;
> +               goto err_put_fd;
> +       }
> +
>         fence2 = sync_file_fdget(data.fd2);
>         if (!fence2) {
>                 err = -ENOENT;
> @@ -504,6 +509,9 @@ static long sync_file_ioctl_fence_info(struct sync_file *sync_file,
>         if (copy_from_user(&in, (void __user *)arg, sizeof(in)))
>                 return -EFAULT;
>
> +       if (in.flags)
> +               return -EINVAL;
> +
>         info = kzalloc(sizeof(*info), GFP_KERNEL);
>         if (!info)
>                 return -ENOMEM;
> diff --git a/drivers/staging/android/uapi/sync.h b/drivers/staging/android/uapi/sync.h
> index a122bb5..11e2d28 100644
> --- a/drivers/staging/android/uapi/sync.h
> +++ b/drivers/staging/android/uapi/sync.h
> @@ -19,11 +19,13 @@
>   * @fd2:       file descriptor of second fence
>   * @name:      name of new fence
>   * @fence:     returns the fd of the new fence to userspace
> + * @flags:     merge_data flags
>   */
>  struct sync_merge_data {
>         __s32   fd2;
>         char    name[32];
>         __s32   fence;
> +       __u32   flags;
The comment from last round still stands, struct size must be multiple
of 64bits. As is the struct will be broken whenever/if we decide to
extend it. See [1] for an alternative wording.

>  };
>
>  /**
> @@ -31,12 +33,14 @@ struct sync_merge_data {
>   * @obj_name:          name of parent sync_timeline
>   * @driver_name:       name of driver implementing the parent
>   * @status:            status of the fence 0:active 1:signaled <0:error
> + * @flags:             fence_info flags
>   * @timestamp_ns:      timestamp of status change in nanoseconds
>   */
>  struct sync_fence_info {
>         char    obj_name[32];
>         char    driver_name[32];
>         __s32   status;
> +       __u32   flags;
>         __u64   timestamp_ns;
>  };
>
> @@ -44,6 +48,7 @@ struct sync_fence_info {
>   * struct sync_file_info - data returned from fence info ioctl
>   * @name:      name of fence
>   * @status:    status of fence. 1: signaled 0:active <0:error
> + * @flags:     sync_file_info flags
>   * @num_fences number of fences in the sync_file
>   * @sync_fence_info: pointer to array of structs sync_fence_info with all
>   *              fences in the sync_file
> @@ -51,6 +56,7 @@ struct sync_fence_info {
>  struct sync_file_info {
>         char    name[32];
>         __s32   status;
> +       __u32   flags;
>         __u32   num_fences;
>
>         __u64   sync_fence_info;
Thanks for taking my suggestion and dropping len. Although I fear that
we introduced a hole which we should be explicitly padded [2].

In both cases the pad should be checked for 0 and -EINVAL should be
returned if that's not the case. This will allow us to potentially
reuse in the future.

Other than that I believe the series looks pretty much spot on.

Cheers,
Emil

[1] https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/Documentation/ioctl/botching-up-ioctls.txt#n37
[2] https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/Documentation/ioctl/botching-up-ioctls.txt#n32
Hi Emil,

2016-03-02 Emil Velikov <emil.l.velikov@gmail.com>:

> On 1 March 2016 at 13:13, Gustavo Padovan <gustavo@padovan.org> wrote:
> > From: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
> >
> > Play safe and add flags member to all structs. So we don't need to
> > break API or create new IOCTL in the future if new features that requires
> > flags arises.
> >
> > v2: check if flags are valid (zero, in this case)
> >
> > v3: return -EINVAL if flags are not zero'ed
> >
> > Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
> > ---
> >  drivers/staging/android/sync.c      | 8 ++++++++
> >  drivers/staging/android/uapi/sync.h | 6 ++++++
> >  2 files changed, 14 insertions(+)
> >
> > diff --git a/drivers/staging/android/sync.c b/drivers/staging/android/sync.c
> > index 3604e453..3c265ed 100644
> > --- a/drivers/staging/android/sync.c
> > +++ b/drivers/staging/android/sync.c
> > @@ -445,6 +445,11 @@ static long sync_file_ioctl_merge(struct sync_file *sync_file,
> >                 goto err_put_fd;
> >         }
> >
> > +       if (data.flags) {
> > +               err = -EINVAL;
> > +               goto err_put_fd;
> > +       }
> > +
> >         fence2 = sync_file_fdget(data.fd2);
> >         if (!fence2) {
> >                 err = -ENOENT;
> > @@ -504,6 +509,9 @@ static long sync_file_ioctl_fence_info(struct sync_file *sync_file,
> >         if (copy_from_user(&in, (void __user *)arg, sizeof(in)))
> >                 return -EFAULT;
> >
> > +       if (in.flags)
> > +               return -EINVAL;
> > +
> >         info = kzalloc(sizeof(*info), GFP_KERNEL);
> >         if (!info)
> >                 return -ENOMEM;
> > diff --git a/drivers/staging/android/uapi/sync.h b/drivers/staging/android/uapi/sync.h
> > index a122bb5..11e2d28 100644
> > --- a/drivers/staging/android/uapi/sync.h
> > +++ b/drivers/staging/android/uapi/sync.h
> > @@ -19,11 +19,13 @@
> >   * @fd2:       file descriptor of second fence
> >   * @name:      name of new fence
> >   * @fence:     returns the fd of the new fence to userspace
> > + * @flags:     merge_data flags
> >   */
> >  struct sync_merge_data {
> >         __s32   fd2;
> >         char    name[32];
> >         __s32   fence;
> > +       __u32   flags;
> The comment from last round still stands, struct size must be multiple
> of 64bits. As is the struct will be broken whenever/if we decide to
> extend it. See [1] for an alternative wording.
> 
> >  };
> >
> >  /**
> > @@ -31,12 +33,14 @@ struct sync_merge_data {
> >   * @obj_name:          name of parent sync_timeline
> >   * @driver_name:       name of driver implementing the parent
> >   * @status:            status of the fence 0:active 1:signaled <0:error
> > + * @flags:             fence_info flags
> >   * @timestamp_ns:      timestamp of status change in nanoseconds
> >   */
> >  struct sync_fence_info {
> >         char    obj_name[32];
> >         char    driver_name[32];
> >         __s32   status;
> > +       __u32   flags;
> >         __u64   timestamp_ns;
> >  };
> >
> > @@ -44,6 +48,7 @@ struct sync_fence_info {
> >   * struct sync_file_info - data returned from fence info ioctl
> >   * @name:      name of fence
> >   * @status:    status of fence. 1: signaled 0:active <0:error
> > + * @flags:     sync_file_info flags
> >   * @num_fences number of fences in the sync_file
> >   * @sync_fence_info: pointer to array of structs sync_fence_info with all
> >   *              fences in the sync_file
> > @@ -51,6 +56,7 @@ struct sync_fence_info {
> >  struct sync_file_info {
> >         char    name[32];
> >         __s32   status;
> > +       __u32   flags;
> >         __u32   num_fences;
> >
> >         __u64   sync_fence_info;
> Thanks for taking my suggestion and dropping len. Although I fear that
> we introduced a hole which we should be explicitly padded [2].
> 
> In both cases the pad should be checked for 0 and -EINVAL should be
> returned if that's not the case. This will allow us to potentially
> reuse in the future.
> 
> Other than that I believe the series looks pretty much spot on.

I agree with both suggestions, a new version of the patches is on the
way.

	Gustavo