Peter Zijlstra says:

Address KCOV vs noinstr. There is no function attribute to selectively
suppress KCOV instrumentation, instead teach objtool to NOP out the
calls in noinstr functions.

This cures a bunch of KCOV crashes (as used by syzcaller).
-----BEGIN PGP SIGNATURE-----
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=0Wd6
-----END PGP SIGNATURE-----