tree 799c7c90b5b6d5c483cd5fb2f77020b6ef8e3d6a
parent 644472649c723bfeb90be0a128d02ea2011e5f56
author Juan Castillo <juan.castillo@arm.com> 1446804097 +0000
committer Juan Castillo <juan.castillo@arm.com> 1447411886 +0000

Add NULL pointer check before reading BL32 entry point information

BL2 is responsible for loading BL32 and passing a pointer to the
BL32 entrypoint info to BL31 in the BL31 parameters. If no BL32
image is loaded, a NULL pointer is passed. The platform is
responsible for accessing BL31 parameters and extracting the
corresponding BL32 EP info.

In ARM platforms, arm_bl31_early_platform_setup() dereferences the
pointer to the BL32 EP info without checking first if the pointer
is NULL. This will cause an exception if a BL32 entrypoint has not
been populated by BL2. FVP and Juno are not affected because they
always define BL32_BASE, irrespective of whether a BL32 image is
included in the FIP or not.

This patches fixes the issue by checking the BL32 ep_info pointer
before trying to access the data.

If `RESET_TO_BL31` is enabled, the BL32 entrypoint is not
populated if BL32_BASE is not defined.

NOTE: Maintainers of partner platforms should check for this issue
in their ports.

Fixes ARM-software/tf-issues#320

Change-Id: I31456155503f2765766e8b7cd30ab4a40958fb96