Re: [REGRESSION] module BTF validation failure (Error -22) on next

From: Cong Wang
Date: Wed Jan 15 2025 - 12:38:31 EST


On Mon, Dec 16, 2024 at 03:19:01PM +0000, Alan Maguire wrote:
> Seems like there's a few approaches we can take in fixing this:
>
> 1. designate "__pcpu_" prefix as a variable prefix to filter out. This
> resolves the immediate problem but is too narrowly focused IMO and we
> may end up playing whack-a-mole with other dummy variable prefixes.
> 2. resurrect ELF section variable information fully; i.e. record a list
> of variables per ELF section (or at least per ELF section we care
> about). If variable is not on the list for the ELF section, do not
> encode it.
> 3. midway between the two; for the 0 address case specifically, verify
> that the variable name really _is_ in the associated ELF section. No
> need to create a local ELF table variable representation, we could just
> walk the table in the case of the 0 addresses.
>
> Diff for approach 3 is as follows

Hi Alan,

Thanks for your detailed analysis.

Is your patch formally submitted and merged? A quick code search with
variable_in_sec() tells me no, but I could very easily miss things here,
hence I am asking you. :)