1. 22 May, 2009 20 commits
  2. 21 May, 2009 2 commits
  3. 20 May, 2009 17 commits
  4. 19 May, 2009 1 commit
    • Benjamin Herrenschmidt's avatar
      drm: Round size of SHM maps to PAGE_SIZE · b6741377
      Benjamin Herrenschmidt authored
      Currently, userspace can fail to obtain the SAREA mapping (among other
      reasons) if it passes SAREA_MAX to drmAddMap without aligning it to the
      page size. This breaks for example on PowerPC with 64K pages and radeon
      despite the kernel radeon actually doing the right rouding in the first
      place.
      
      The way SAREA_MAX is defined with a bunch of ifdef's and duplicated
      between libdrm and the X server is gross, ultimately it should be
      retrieved by userspace from the kernel, but in the meantime, we have
      plenty of existing userspace built with bad values that need to work.
      
      This patch works around broken userspace by rounding the requested size
      in drm_addmap_core() of any SHM map to the page size. Since the backing
      memory for SHM maps is also allocated within addmap_core, there is no
      danger of adjacent memory being exposed due to the increased map size.
      The only side effect is that drivers that previously tried to create or
      access SHM maps using a size < PAGE_SIZE and failed (getting -EINVAL),
      will now succeed at the cost of a little bit more memory used if that
      happens to be when the map is created.
      Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
      Signed-off-by: default avatarJesse Barnes <jbarnes@virtuousgeek.org>
      b6741377