malta: Add kernel 6.6 support

[hauke]

This adds basic kernel 6.6 support to the MIPS malta target.

[guidosarducci]

Thanks for this, and also apparently doing some "all modules" builds to shake out problems -- certainly time-consuming. I was in the middle of testing my own malta 6.6 PR, but yours looks fully baked so looking forward to seeing it merged.

I can confirm no major changes were needed for 6.6, at least with malta/mipseb32 and malta/mipsel64 which I tested. The kernel bump did break building kselftests-bpf, a devel package not built by default, so I'm working on some package fixes and also related upstream Linux patches.

I'd also note that of the config changes in 25887c2, many also appear in other arches and could likely be filtered out or pulled into the top-level generic config. But probably best to wait for more 6.6 arch updates before trying to clean up and factor out changes. Cheers!

[guidosarducci]

LGTM

[ehem]

There is a script for this which serves to preserve history. That should be used instead.

[ehem]

There are history preserving scripts for this, those should be used instead.

[sbwml]

I can confirm no major changes were needed for 6.6, at least with malta/mipseb32 and malta/mipsel64 which I tested. The kernel bump did break building kselftests-bpf, a devel package not built by default, so I'm working on some package fixes and also related upstream Linux patches.

Hi! Do you have any progress on linux-6.6 kselftests-bpf?

Initially, I encountered an error: cc: error: unrecognized command-line option '-fhonour-copts'; did you mean '-fhonor-std'?

---

I attempted to remove -fhonour-copts from TARGET_CFLAGS：

package/devel/kselftests-bpf/Makefile

TARGET_CFLAGS := $(subst -fhonour-copts,,$(TARGET_CFLAGS))

Afterward, I encountered another error:

make[3]: Entering directory '/home/sbwml/openwrt/build_dir/target-x86_64_musl/linux-x86_64/linux-6.6.22/tools/testing/selftests/bpf'
  MKDIR    libbpf
In file included from <command-line>:
/home/sbwml/openwrt/staging_dir/toolchain-x86_64_gcc-14.0.1_musl/include/stdc-predef.h:10: error: "__STDC_UTF_16__" redefined [-Werror]
   10 | #define __STDC_UTF_16__ 1
      | 
<built-in>: note: this is the location of the previous definition
In file included from <command-line>:
/home/sbwml/openwrt/staging_dir/toolchain-x86_64_gcc-14.0.1_musl/include/stdc-predef.h:11: error: "__STDC_UTF_32__" redefined [-Werror]
   11 | #define __STDC_UTF_32__ 1
      | 
<built-in>: note: this is the location of the previous definition
cc1: all warnings being treated as errors

😔 I have no way to handle this error. I hope this error is not because I'm using GCC14. After all, for me, it is very difficult to switch toolchains for testing, and it requires a lot of time.

[guidosarducci]

Hi! Do you have any progress on linux-6.6 kselftests-bpf?

Initially, I encountered an error: cc: error: unrecognized command-line option '-fhonour-copts'; did you mean '-fhonor-std'?

😔 I have no way to handle this error. I hope this error is not because I'm using GCC14. After all, for me, it is very difficult to switch toolchains for testing, and it requires a lot of time.

@sbwml Hello, I'm the author and maintainer of kselftests-bpf package. Yes, I fixed it while also adding kernel 6.6 support for malta on my own. Seeing the changes from @hauke I decided to let him merge this first before re-testing and submitting my kselftests-bpf updates. I'll let him comment on what the issue might be delaying this PR. Since kselftests-bpf isn't built by default it shouldn't be a problem; do you need it for something you're working on?

I've tested with both GCC 12 and 13 and confirm it works fine; GCC 14 hasn't been released AFAIK so I wouldn't consider it reliable to use or worthwhile to troubleshoot.

[sbwml]

@sbwml Hello, I'm the author and maintainer of kselftests-bpf package. Yes, I fixed it while also adding kernel 6.6 support for malta on my own. Seeing the changes from @hauke I decided to let him merge this first before re-testing and submitting my kselftests-bpf updates. I'll let him comment on what the issue might be delaying this PR. Since kselftests-bpf isn't built by default it shouldn't be a problem; do you need it for something you're working on?

Thanks for your reply, I found the answer in your warehouse guidosarducci/openwrt/commits/master-test-misc-6.6, and now kselftests-bpf has been successfully built

[guidosarducci]

@hauke Can this be merged now or are there some issues remaining? Having this would simplify upstream kernel testing...