CRYPTO_SESSION_IS_BUSY
if (sp->sd_flags & CRYPTO_SESSION_IS_BUSY) {
while (sp->sd_flags & CRYPTO_SESSION_IS_BUSY) {
sp->sd_flags |= CRYPTO_SESSION_IS_BUSY;
(s)->sd_flags &= ~CRYPTO_SESSION_IS_BUSY; \
ASSERT(((sp)->sd_flags & CRYPTO_SESSION_IS_BUSY) != 0); \
ASSERT((sp->sd_flags & CRYPTO_SESSION_IS_BUSY) == 0);