cbfs: Check return value of map() for error

The CBFS core checks the result of a media->map() operation in multiple
places for CBFS_MEDIA_INVALID_MAP_ADDRESS, suggesting that this is a
valid response. However, it ironically fails to do so when actually
mapping the CBFS file itself, which can fail on buffer-constrained
systems since the size is much larger than when mapping metadata. This
patch adds a check with an error message and a NULL pointer return for
that case to make it easier to understand this condition.

Change-Id: Icae3dd20d3d111cdfc4f2dc6397b52174349b140
Signed-off-by: Julius Werner <jwerner@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/174951
Reviewed-by: Gabe Black <gabeblack@chromium.org>
Reviewed-by: Hung-Te Lin <hungte@chromium.org>
(cherry picked from commit 63f2c4465f9633a637186e69bc3862d5413106ac)
Signed-off-by: Isaac Christensen <isaac.christensen@se-eng.com>
Reviewed-on: http://review.coreboot.org/6537
Tested-by: build bot (Jenkins)
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>
1 file changed