On Fri, May 31, 2024 at 01:06:41PM -0300, Arnaldo Carvalho de Melo wrote: > On Fri, May 31, 2024 at 03:49:38AM -0700, Tony Ambardar wrote: > > Hello Hengqi, > > > > On Fri, May 31, 2024 at 10:17:53AM +0800, Hengqi Chen wrote: > > > Hi Tony, > > > > > > On Fri, May 31, 2024 at 9:30 AM Tony Ambardar <tony.ambardar@xxxxxxxxx> wrote: > > > > > > > > Hello, > > > > > > > > For some time now I'm seeing multiple issues during BTF generation while > > > > building recent kernels targeting mips64el, and would appreciate some help > > > > to understand and fix the problems. > > > > > > > SNIP > > > > > > > > > CC [M] net/ipv6/netfilter/nft_fib_ipv6.mod.o > > > > > CC [M] net/ipv6/netfilter/ip6t_REJECT.mod.o > > > > > CC [M] net/psample/psample.mod.o > > > > > LD [M] crypto/cmac.ko > > > > > BTF [M] crypto/cmac.ko > > > > > die__process: DW_TAG_compile_unit, DW_TAG_type_unit, DW_TAG_partial_unit > > > > > or DW_TAG_skeleton_unit expected got member (0xd)! > > Can you check the kernel CONFIG_ variables related to DEBUG information > and post them here? I have this on fedora: > > [acme@nine linux]$ grep CONFIG_DEBUG_INFO /boot/config-5.14.0-362.18.1.el9_3.x86_64 > CONFIG_DEBUG_INFO=y > # CONFIG_DEBUG_INFO_REDUCED is not set > # CONFIG_DEBUG_INFO_COMPRESSED is not set > # CONFIG_DEBUG_INFO_SPLIT is not set > CONFIG_DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT=y > # CONFIG_DEBUG_INFO_DWARF4 is not set > # CONFIG_DEBUG_INFO_DWARF5 is not set > CONFIG_DEBUG_INFO_BTF=y > CONFIG_DEBUG_INFO_BTF_MODULES=y > [acme@nine linux]$ > > If you have CONFIG_DEBUG_INFO_SPLIT, CONFIG_DEBUG_INFO_COMPRESSED or > CONFIG_DEBUG_INFO_REDUCED set to 'y', please try with the values in the > fedora config. One more useful observation: the pahole BTF generation problems appear only for mips64. If I build the same config for mips32be I see none of those "die__process: errors" from pahole and the processed modules load properly. I also tried running pahole under gdb to look further, but lack knowledge of pahole and libdw internals, so couldn't narrow things down to a pahole, elfutils or compiler-output problem. To help troubleshoot further, I packaged my base vmlinux, some module .ko files showing problems, and a reproducer script. I've uploaded the tarball here: https://www.dropbox.com/scl/fi/3ce22fi2q861wqvbq9mwy/repro_die__process.tar.xz?rlkey=ev494phabmfl5qe55xrn1jh3t&st=vrp5mxhh&dl=0 Thanks, Tony > > - Arnaldo > > > > The issue seems to be related to elfutils. Have you tried build from > > > the latest elfutils source ? > > > I saw the latest MIPS backend in elfutils already implemented the > > > reloc_simple_type hook. > > > > Good idea. I tried rebuilding elfutils from the latest upstream commit: > > https://sourceware.org/git/?p=elfutils.git;a=commit;h=935ee131cf7c87296df9412b7e3370085e7c7508 > > > > I then linked this elfutils with pahole built from the latest pahole/next: > > https://git.kernel.org/pub/scm/devel/pahole/pahole.git/commit/?h=next&id=a9ae414fef421bdeb13ff7ffe13271e1e4f58993 > > > > I also confirmed resolve_btfids links to the new elfutils, and then rebuilt > > the kernel with the same config. Unfortunately, the warnings/errors from > > resolve_btfids and pahole still occur. > > > > > SNIP > > > > > > > > I'd be grateful if some of the BTF/pahole experts could please review this > > > > issue and share next steps or other details I might provide. > > > > > > > > Thanks, > > > > Tony Ambardar > > > > > > > > Link: https://lore.kernel.org/all/202401211357.OCX9yllM-lkp@xxxxxxxxx/ [1] > > > > Link: https://github.com/acmel/dwarves/issues/45 [2] > > > > > > Cheers, > > > Hengqi > > > > Thanks for the suggestion, > > Tony
