6be8f3bd2c
For buffer sharing, use dma-buf instead. We can't set smem_start to 0 unconditionally since that's used by the fbdev mmap default implementation. And we have plenty of userspace which would like to keep that working. This might break legit userspace - if it does we need to look at a case-by-cases basis how to handle that. Worst case I expect overrides for only specific drivers, since anything remotely modern should be using dma-buf/prime now (which is about 7 years old now for DRM drivers). This issue was uncovered because Noralf's rework to implement a generic fb_probe also implements it's own fb_mmap callback. Which means smem_start didn't have to be set anymore, which blew up some blob in userspace rather badly. Acked-by: Sean Paul <seanpaul@chromium.org> Cc: Gustavo Padovan <gustavo@padovan.org> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Cc: Sean Paul <sean@poorly.run> Cc: David Airlie <airlied@linux.ie> Cc: John Stultz <john.stultz@linaro.org> Cc: Noralf Trønnes <noralf@tronnes.org> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20180822085405.10787-4-daniel.vetter@ffwll.ch
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.