Yeah, that's definitely not the right signature for sdot when linked against the Accelerate framework.
But what's the purpose of those wrappers in _umath_linalg? The one for sdot, for example, doesn't appear to be used internally, and it isn't available from the python side. While scipy has all of those function pointers accessible in scipy.linalg.blas (e.g. scipy.linalg.blas.sdot._cpointer), those function pointers point to the underlying blas function and expose the ABI differences between platforms, leading to, for example the utter nightmare of using the scipy blas function pointers from cython in a cross platform way:
https://gist.github.com/anonymous/6659007.
-Robert