Re: [PATCH RFC bpf-next 1/4] bpf: add struct largest member size in func model

On Fri, 2025-04-25 at 17:23 +0800, Xu Kuohai wrote:

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For the two questions you mentioned, I’m not sure if we can access DWARF attributes at runtime. As for adding parameter locations to BTF at building time, I think it means we would need to record CPU-related register info in BTF, which I don’t think is a good idea.

Another option would be for pahole to check if function parameter DW_AT_locaction is placed in accordance with ABI. These flags can be recorded in a dedicated section or smth like this. Having said that, DW_AT_locaction seem to be not very reliable. E.g. for bpf_testmod.ko generated by clang 19.1.7 I don't see DW_AT_locaction specified for parameters a, b, c.