the call to data_abort_fixup() as the fixup routines also try to
de-reference the fault pc.
- If a fault came from kernel mode, and the fault address looks to be in
the kernel's address space, and pcb_onfault is *set*, check the
instruction which caused the fault. If it's LDR{B,}T or STR{B,}T
then one of the copy in/out routines is trying to read/write a
kernel address with the wrong privilege. If that address is actually
mapped, we could end up in an infinite loop because we failed to
notice that it's really a 'user mode' access. Yay for "crashme".
I suspect this also fixes PR port-arm/23052.
Note: This *could* be fixed by adding sanity checks to copyin et al,
but that would add extra overhead to the non-error path...
- Fix a couple of __predict_false cases.
a590a31135