Browse Source
There are many instances in ARM Trusted Firmware where control is transferred to functions from which return isn't expected. Such jumps are made using 'bl' instruction to provide the callee with the location from which it was jumped to. Additionally, debuggers infer the caller by examining where 'lr' register points to. If a 'bl' of the nature described above falls at the end of an assembly function, 'lr' will be left pointing to a location outside of the function range. This misleads the debugger back trace. This patch defines a 'no_ret' macro to be used when jumping to functions from which return isn't expected. The macro ensures to use 'bl' instruction for the jump, and also, for debug builds, places a 'nop' instruction immediately thereafter (unless instructed otherwise) so as to leave 'lr' pointing within the function range. Change-Id: Ib34c69fc09197cfd57bc06e147cc8252910e01b0 Co-authored-by: Douglas Raillard <douglas.raillard@arm.com> Signed-off-by: Jeenu Viswambharan <jeenu.viswambharan@arm.com>pull/774/head
Jeenu Viswambharan
8 years ago
19 changed files with 122 additions and 78 deletions
Loading…
Reference in new issue