Re: Introduce a new helper framework for buffer synchronization

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Op 09-05-13 09:33, Inki Dae schreef:
> Hi all,
>
> This post introduces a new helper framework based on dma fence. And the
> purpose of this post is to collect other opinions and advices before RFC
> posting.
>
> First of all, this helper framework, called fence helper, is in progress
> yet so might not have enough comments in codes and also might need to be
> more cleaned up. Moreover, we might be missing some parts of the dma fence.
> However, I'd like to say that all things mentioned below has been tested
> with Linux platform and worked well.

> ....
>
> And tutorial for user process.
>         just before cpu access
>                 struct dma_buf_fence *df;
>
>                 df->type = DMA_BUF_ACCESS_READ or DMA_BUF_ACCESS_WRITE;
>                 ioctl(fd, DMA_BUF_GET_FENCE, &df);
>
>         after memset or memcpy
>                 ioctl(fd, DMA_BUF_PUT_FENCE, &df);
NAK.

Userspace doesn't need to trigger fences. It can do a buffer idle wait, and postpone submitting new commands until after it's done using the buffer.
Kernel space doesn't need the root hole you created by giving a dereferencing a pointer passed from userspace.
Your next exercise should be to write a security exploit from the api you created here. It's the only way to learn how to write safe code. Hint: df.ctx = mmap(..);

~Maarten
_______________________________________________
dri-devel mailing list
dri-devel@xxxxxxxxxxxxxxxxxxxxx
http://lists.freedesktop.org/mailman/listinfo/dri-devel




[Index of Archives]     [Linux DRI Users]     [Linux Intel Graphics]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]     [XFree86]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Linux Kernel]     [Linux SCSI]     [XFree86]
  Powered by Linux