Hi Mark, On Mon, Jun 03, 2024 at 09:18:33PM +0200, Mark Wielaard wrote: > On Mon, Jun 03, 2024 at 02:40:45PM -0300, Arnaldo Carvalho de Melo wrote: > > Couldn't find a way to ask eu-readelf for more verbose output, where we > > could perhaps get some clue as to why it produces nothing while binutils > > readelf manages to grok it, Mark, do you know some other way to ask > > eu-readelf to produce more debug output? > > > > I'm unsure if the netdevsim.ko file was left in a semi encoded BTF state > > that then made eu-readelf to not be able to process it while pahole, > > that uses eltuils' libraries, was able to process the first two CUs for > > a kernel module and all the CUs for the vmlinux file :-\ > > > > Mark, the whole thread is available at: > > > > https://lore.kernel.org/all/Zl3Zp5r9m6X_i_J4@x1/T/#u > > I haven't looked at the vmlinux file. But for the .ko file the issue > is that the elfutils MIPS backend isn't complete. Specifically MIPS > relocations aren't recognized (and so cannot be applied). There are > some pending patches which try to fix that: > > https://patchwork.sourceware.org/project/elfutils/list/?series=31601 Earlier in the thread, Hengqi Chen pointed out the latest elfutils backend work for MIPS, and I locally rebuilt elfutils and then pahole from their respective next/main branches. For elfutils, main (935ee131cf7c) includes e259f126 Support Mips architecture f2acb069 stack: Fix stack unwind failure on mips db33cb0c backends: Add register_info, return_value_location, core_note mips which partially applies the patchwork series but leaves out the support for readelf, strip, and elflint. I believe this means the vmlinux and .ko files I shared are OK, or is there more backend work needed for MIPS? The bits missing in eu-readelf would explain the blank output both Arnaldo and I see from "$ eu-readelf -winfo vmlinux". I tried rebuilding with the patchwork readelf patch locally but ran into merge conflicts. CCing Ying Huang for any more insight. Thanks, Tony
