Commits
Max Filippov committed 17290231df1
xtensa: add fixup for double exception raised in window overflow 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 Cc: stable@vger.kernel.org Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>