qemu-rv's S-mode/non-SMP setintstack unconditionally reloaded sp to
the top of the per-cpu interrupt stack. A trap taken while already
running on that stack rewound sp back to the same address, so the
nested trap's frame overwrote the still-live outer trap's frame.
Port the bounds check already used by the canonical setintstack in
riscv_macros.S: only move sp when it is outside the interrupt stack
range.
Other vendor chip.h files have the same unconditional-reload pattern
and are left for a follow-up.
Signed-off-by: liang.huang <liang.huang@houmo.ai>
32cf92db24