Re: [Linaro-mm-sig] [PATCHv2 4/4] staging: android: ion: Add ioctl to query available heaps

On Thu, Sep 01, 2016 at 03:40:44PM -0700, Laura Abbott wrote:

Ion clients currently lack a good method to determine what heaps are available and what ids they map to. This leads to tight coupling between user and kernel space and headaches. Add a query ioctl to let userspace know the availability of heaps.

Signed-off-by: Laura Abbott labbott@redhat.com

drivers/staging/android/ion/ion-ioctl.c | 11 +++++++++ drivers/staging/android/ion/ion.c | 44 +++++++++++++++++++++++++++++++++ drivers/staging/android/ion/ion_priv.h | 3 +++ drivers/staging/android/uapi/ion.h | 39 +++++++++++++++++++++++++++++ 4 files changed, 97 insertions(+)

diff --git a/drivers/staging/android/ion/ion-ioctl.c b/drivers/staging/android/ion/ion-ioctl.c index 53b9520..e76d517 100644 --- a/drivers/staging/android/ion/ion-ioctl.c +++ b/drivers/staging/android/ion/ion-ioctl.c @@ -28,6 +28,7 @@ union ion_ioctl_arg { struct ion_handle_data handle; struct ion_custom_data custom; struct ion_abi_version abi_version;

• struct ion_heap_query query;

}; static int validate_ioctl_arg(unsigned int cmd, union ion_ioctl_arg *arg) @@ -38,6 +39,11 @@ static int validate_ioctl_arg(unsigned int cmd, union ion_ioctl_arg *arg) case ION_IOC_ABI_VERSION: ret = arg->abi_version.reserved != 0; break;

• case ION_IOC_HEAP_QUERY:

• ret = arg->query.reserved0 != 0;
  

• ret |= arg->query.reserved1 != 0;
  

• ret |= arg->query.reserved2 != 0;
  

• break;
  

  default: break; }

@@ -162,6 +168,11 @@ long ion_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) data.abi_version.abi_version = ION_ABI_VERSION; break; }

• case ION_IOC_HEAP_QUERY:
• {

• ret = ion_query_heaps(client, &data.query);
  

• break;
  

• }

Minor nit, the { } aren't needed here. Yeah, I know the other cases have them, but they aren't all needed there either, no need to keep copying bad code style :)

default: return -ENOTTY; } diff --git a/drivers/staging/android/ion/ion.c b/drivers/staging/android/ion/ion.c index 975b48f..91b765c 100644 --- a/drivers/staging/android/ion/ion.c +++ b/drivers/staging/android/ion/ion.c @@ -1174,6 +1174,49 @@ int ion_sync_for_device(struct ion_client *client, int fd) return 0; } +int ion_query_heaps(struct ion_client *client, struct ion_heap_query *query) +{

• struct ion_device *dev = client->dev;
• struct ion_heap_data __user *buffer =

• (struct ion_heap_data __user *)query->heaps;
  

Shouldn't query be marked as __user instead of having this cast?

• int ret = -EINVAL, cnt = 0, max_cnt;
• struct ion_heap *heap;
• struct ion_heap_data hdata;
• memset(&hdata, 0, sizeof(hdata));
• down_read(&dev->lock);
• if (!buffer) {

• query->cnt = dev->heap_cnt;
  

Wait, query is __user?

I think the mixing of user/kernel pointers here isn't quite right, or I just really can't figure it out...

And kbuild didn't seem to like this patch either :(

But your first 2 patches are great, I'll queue them up later today.

thanks,

greg k-h