Re: [PATCH dwarves v7 0/5] pahole: Encode true signatures in kernel BTF
Jiri Olsa <[email protected]> Wed, 24 Jun 2026 11:28:04 +0200
| Newsgroups | org.kernel.vger.dwarves,org.kernel.vger.bpf |
|---|---|
| Message-ID | <ajujJM9N0_QpB_3d@krava> |
On Tue, Jun 23, 2026 at 05:02:30PM +0100, Alan Maguire wrote: SNIP > >> > >> hi, > >> I tried to get the numbers from my setup and noticed that some new > >> functions were included in BTF compared to the current version > >> (functions diff attached below) > >> > >> like for "arp_process" function the current pahole gives me: > >> > >> arp_process : skipping BTF encoding of function due to unexpected register usage for parameter > >> > >> but it's included in BTF generated with the new pahole. > >> > >> in addition to your explanation above also one of the commit says: > >> > >> - a parameter with no location, a constant value, or (for non-clang) no > >> register found is marked optimized out > >> > >> please check below, it seems like 2nd argument of arp_process has no location, > >> so iiuc it should not be included in BTF, right? > >> > >> thanks, > >> jirka > >> > >> > > > > thanks for catching this; it looks like we return a bit early before detecting > > missing locations in the non-true-signature code. If you get a chance, would you > > mind trying the attached patch to see if it fixes the problem? > > > > If the fix works and Yonghong is happy with it we can add it as a followup > > and land the true signature series to save another round. > > actually sorry that patch leaked true signature partial names for gcc; updated > patch attached. hum, I can't apply either of them, but I see that change on top of: alan-maguire/dwarves-true-sig-v7 but on that branch I can still see arp_process function in the btf please let me know if I should try some other branch thanks, jirka