Hi Emil,
2016-03-02 Emil Velikov <emil.l.velikov@xxxxxxxxx>:
> On 1 March 2016 at 13:13, Gustavo Padovan <gustavo@xxxxxxxxxxx> wrote:
> > From: Gustavo Padovan <gustavo.padovan@xxxxxxxxxxxxxxx>
> >
> > 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@xxxxxxxxxxxxxxx>
> > ---
> > 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
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