* Re: [bpf-next:master 8/9] FAILED: load BTF from .tmp_vmlinux1.BTF.1: No such file or directory
2025-12-29 19:28 ` [bpf-next:master 8/9] FAILED: load BTF from .tmp_vmlinux1.BTF.1: No such file or directory Ihor Solodrai
@ 2026-01-05 16:47 ` Alan Maguire
0 siblings, 0 replies; 2+ messages in thread
From: Alan Maguire @ 2026-01-05 16:47 UTC (permalink / raw)
To: Ihor Solodrai, kernel test robot, Dinh Nguyen
Cc: oe-kbuild-all, Andrii Nakryiko, bpf, linux-kbuild, linux-kernel,
dwarves
On 29/12/2025 19:28, Ihor Solodrai wrote:
> On 12/24/25 5:01 PM, kernel test robot wrote:
>> tree: https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git master
>> head: f14cdb1367b947d373215e36cfe9c69768dbafc9
>> commit: 522397d05e7d4a7c30b91841492360336b24f833 [8/9] resolve_btfids: Change in-place update with raw binary output
>> config: nios2-randconfig-001-20251224 (https://download.01.org/0day-ci/archive/20251225/202512250932.X7mdviuH-lkp@intel.com/config)
>> compiler: nios2-linux-gcc (GCC) 11.5.0
>> reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20251225/202512250932.X7mdviuH-lkp@intel.com/reproduce)
>>
>> If you fix the issue in a separate patch/commit (i.e. not just a new version of
>> the same patch/commit), kindly add following tags
>> | Reported-by: kernel test robot <lkp@intel.com>
>> | Closes: https://lore.kernel.org/oe-kbuild-all/202512250932.X7mdviuH-lkp@intel.com/
>>
>> All errors (new ones prefixed by >>):
>>
>> Complex, interval and imaginary float types are not supported
>> Error while encoding BTF.
>
> Hi Dinh, Alan,
>
> Not sure why this has surfaced only now, but it appears that kernel
> build with ARCH=nios2 and CONFIG_DEBUG_INFO_BTF=y has been broken for
> a long time.
>
> I tried the following revisions:
> - bpf-next @ 522397d05e7d as in bug report
> - bpf-next @ 014e1cdb5fad without the gen-btf.sh patch
> - v6.18
> - v6.17
> - v6.12 (~1y ago)
>
> All fail with the same error in pahole [1]:
>
> Complex, interval and imaginary float types are not supported
> Encountered error while encoding BTF.
>
> I used v1.24 in most experiments, the default debian:bookworm
> installation. Upgrading pahole to v1.31 doesn't change this behavior.
>
> I also stumbled on a phoronix article [2], saying Nios II support has
> ended with GCC 15. Is it actively supported in Linux?
>
> Not clear to me if anything needs to be fixed here. I'd appreciate any input.
>
> Thanks.
hi Ihor, it's probably worth separating the issue of complex/interval/imaginary
support from nios2 support. In terms of the latter, if the breakage is old I agree
that it is at least a lower priority. Did you figure out where the problematic
type comes from? Might be a workaround we could apply there.
It also does raise a valid issue about supporting a larger menu of floating-point
types supported by GNU C/C++. To do so it looks like we'd need 2 bits
to support the range of possibilities
- standard floating point
- complex floating point
- interval floating point
- imaginary floating point
Is there interest in supporting these? Thanks!
Alan
>
> [1] https://git.kernel.org/pub/scm/devel/pahole/pahole.git/tree/btf_encoder.c?h=v1.31#n469
> [2] https://www.phoronix.com/news/GCC-15-Drops-Altera-Nios-II
>
>
>>>> FAILED: load BTF from .tmp_vmlinux1.BTF.1: No such file or directory
>>
>
>
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