commit 17290231df upstream.
There are two FIXMEs in the double exception handler 'for the extremely
unlikely case'. This case gets hit by gcc during kernel build once in
a few hours, resulting in an unrecoverable exception condition.
Provide missing fixup routine to handle this case. Double exception
literals now need 8 more bytes, add them to the linker script.
Also replace bbsi instructions with bbsi.l as we're branching depending
on 8th and 7th LSB-based bits of exception address.
This may be tested by adding the explicit DTLB invalidation to window
overflow handlers, like the following:
# --- a/arch/xtensa/kernel/vectors.S
# +++ b/arch/xtensa/kernel/vectors.S
# @@ -592,6 +592,14 @@ ENDPROC(_WindowUnderflow4)
# ENTRY_ALIGN64(_WindowOverflow8)
#
# s32e a0, a9, -16
# + bbsi.l a9, 31, 1f
# + rsr a0, ccount
# + bbsi.l a0, 4, 1f
# + pdtlb a0, a9
# + idtlb a0
# + movi a0, 9
# + idtlb a0
# +1:
# l32e a0, a1, -12
# s32e a2, a9, -8
# s32e a1, a9, -12
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
e4cbf9a98c