On Sun, Dec 14, 2025 at 9:15 AM kernel test robot <[email protected]> wrote:
>
> Hi Donglin,
>
> kernel test robot noticed the following build errors:
>
> [auto build test ERROR on trace/for-next]
> [also build test ERROR on linus/master v6.18 next-20251212]
> [If your patch is applied to the wrong git tree, kindly drop us a note.
> And when submitting patch, we suggest to use '--base' as documented in
> https://git-scm.com/docs/git-format-patch#_base_tree_information]
>
> url:
> https://github.com/intel-lab-lkp/linux/commits/Donglin-Peng/fgraph-Enhance-funcgraph-retval-with-BTF-based-type-aware-output/20251209-201633
> base: https://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
> for-next
> patch link:
> https://lore.kernel.org/r/20251209121349.525641-2-dolinux.peng%40gmail.com
> patch subject: [PATCH v3 1/2] fgraph: Enhance funcgraph-retval with BTF-based
> type-aware output
> config: arm-randconfig-002-20251214
> (https://download.01.org/0day-ci/archive/20251214/[email protected]/config)
> compiler: arm-linux-gnueabi-gcc (GCC) 10.5.0
> reproduce (this is a W=1 build):
> (https://download.01.org/0day-ci/archive/20251214/[email protected]/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 <[email protected]>
> | Closes:
> https://lore.kernel.org/oe-kbuild-all/[email protected]/
>
> All errors (new ones prefixed by >>):
>
> arm-linux-gnueabi-ld: kernel/trace/trace_functions_graph.o: in function
> `trim_retval':
> >> kernel/trace/trace_functions_graph.c:888: undefined reference to
> >> `btf_find_func_proto'
Thanks. I will address this in the next version. The issue occurs because
CONFIG_FUNCTION_GRAPH_RETVAL and CONFIG_DEBUG_INFO_BTF
are enabled, but CONFIG_PROBE_EVENTS_BTF_ARGS is disabled.
This prevents trace_btf.c from being compiled, while the function
btf_find_func_proto
it provides is still required.
Thanks,
Donglin
>
>
> vim +888 kernel/trace/trace_functions_graph.c
>
> 872
> 873 static void trim_retval(unsigned long func, unsigned long *retval,
> bool *print_retval,
> 874 int *fmt)
> 875 {
> 876 const struct btf_type *t;
> 877 char name[KSYM_NAME_LEN];
> 878 struct btf *btf;
> 879 u32 v, msb;
> 880 int kind;
> 881
> 882 if (!IS_ENABLED(CONFIG_DEBUG_INFO_BTF))
> 883 return;
> 884
> 885 if (lookup_symbol_name(func, name))
> 886 return;
> 887
> > 888 t = btf_find_func_proto(name, &btf);
> 889 if (IS_ERR_OR_NULL(t))
> 890 return;
> 891
> 892 t = btf_type_skip_modifiers(btf, t->type, NULL);
> 893 kind = t ? BTF_INFO_KIND(t->info) : BTF_KIND_UNKN;
> 894 switch (kind) {
> 895 case BTF_KIND_UNKN:
> 896 *print_retval = false;
> 897 break;
> 898 case BTF_KIND_STRUCT:
> 899 case BTF_KIND_UNION:
> 900 case BTF_KIND_ENUM:
> 901 case BTF_KIND_ENUM64:
> 902 if (kind == BTF_KIND_STRUCT || kind == BTF_KIND_UNION)
> 903 *fmt = RETVAL_FMT_HEX;
> 904 else
> 905 *fmt = RETVAL_FMT_DEC;
> 906
> 907 if (t->size > sizeof(unsigned long)) {
> 908 *fmt |= RETVAL_FMT_TRUNC;
> 909 } else {
> 910 msb = BITS_PER_BYTE * t->size - 1;
> 911 *retval &= GENMASK(msb, 0);
> 912 }
> 913 break;
> 914 case BTF_KIND_INT:
> 915 v = *(u32 *)(t + 1);
> 916 if (BTF_INT_ENCODING(v) == BTF_INT_BOOL) {
> 917 *fmt = RETVAL_FMT_BOOL;
> 918 msb = 0;
> 919 } else {
> 920 if (BTF_INT_ENCODING(v) == BTF_INT_SIGNED)
> 921 *fmt = RETVAL_FMT_DEC;
> 922 else
> 923 *fmt = RETVAL_FMT_HEX;
> 924
> 925 if (t->size > sizeof(unsigned long)) {
> 926 *fmt |= RETVAL_FMT_TRUNC;
> 927 msb = BITS_PER_LONG - 1;
> 928 } else {
> 929 msb = BTF_INT_BITS(v) - 1;
> 930 }
> 931 }
> 932 *retval &= GENMASK(msb, 0);
> 933 break;
> 934 default:
> 935 *fmt = RETVAL_FMT_HEX;
> 936 break;
> 937 }
> 938 }
> 939
>
> --
> 0-DAY CI Kernel Test Service
> https://github.com/intel/lkp-tests/wiki
