arc: stack guard: bug fix with multi push stack situation
accessing the stack below guard_end is always a bug. some
instrustions (like enter_s {r13-r26, fp, blink}) push a collection
of registers on to the stack. In this situation, the fault_addr will
less than guard_end, but sp will greater than guard_end.
|------stack base-------| <--- high address
| |
| | <--- sp
|------stack top--------|
|------guard_end--------|
| | <--- fault_addr
| |
|------guard_start------| <--- low address
So we need to remove the SP check. Trade-off here is if we prefer
'false' classifications of MPU stack guard area accesses as stack
error or as general mpu error. The faults get caught anyway, this is
just about classification: don't see a strong need for the extra check
to only report stack pointer accesses to guard area as stack error,
instead of all accesses.
Signed-off-by: Watson Zeng <zhiwei@synopsys.com>
1 file changed
