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The previous check returned -1 when any page within [start, start+len) is unmapped, not when all are unmapped. Cc: Warner Losh <imp@bsdimp.com> Cc: Kyle Evans <kevans@freebsd.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org> Reviewed-by: Warner Losh <imp@bsdimp.com> Message-Id: <20230707204054.8792-11-richard.henderson@linaro.org>