[DTrace-devel] [External] : Re: [PATCH 5/6] fbt: retrieve function return value using helper

[Nick Alcock]

On 28 Apr 2026, Kris Van Hees outgrape:

> We were causing BPF verifier errors when trying to access the return value
> of some functions due to incorrect calculation of the offset to read from.
> Rather than implementing the more complex logic needed to calculate the
> proper offset of the return value, we can just use the bpf_get_func_ret()
> BPF helper.  This does not impose a performance decrease because that
> helper gets inlined by the BPF verifier.

Presumably we are a suitable probe type? ... yes, we are.

> Signed-off-by: Kris Van Hees <kris.van.hees at oracle.com>

Reviewed-by: Nick Alcock <nick.alcock at oracle.com>

Looks much nicer.

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