Hi Jiri, On Wed, 26 Jul 2023 12:04:08 +0200 Jiri Olsa <olsajiri@xxxxxxxxx> wrote: > On Wed, Jul 26, 2023 at 10:25:34AM +0900, Masami Hiramatsu wrote: > > Hello, > > (I resend this because kconfig was too big) > > > > I found that BTF is not generated for gcc-built kernel with that latest > > pahole (v1.25). > > hi, > I can't reproduce on my setup with your .config > > does 'bpftool btf dump file ./vmlinux' show any error? > > is there any error in the kernel build output? Yes, here it is. I saw these 2 lines. die__process: DW_TAG_compile_unit, DW_TAG_type_unit, DW_TAG_partial_unit or DW_TAG_skeleton_unit expected got INVALID (0x0)! die__process: DW_TAG_compile_unit, DW_TAG_type_unit, DW_TAG_partial_unit or DW_TAG_skeleton_unit expected got INVALID (0x0)! > > > When I'm using the distro origin pahole (v1.22) it works. (I also checked > > v1.23 and v1.24, both partially generated BTF) > > > > e.g. > > > > # echo 'f kfree $arg*' >> /sys/kernel/tracing/dynamic_events > > sh: write error: Invalid argument > > > > # cat /sys/kernel/tracing/error_log > > [ 21.595724] trace_fprobe: error: BTF is not available or not supported > > Command: f kfree $arg* > > ^ > > [ 21.596032] trace_fprobe: error: Invalid $-valiable specified > > Command: f kfree $arg* > > ^ > > > > / # strings /sys/kernel/btf/vmlinux | grep kfree > > hm, if you have this file present, you have BTF in Yes, it seems that the BTF itself is generated, but many entries seems dropped compared with pahole v1.22. So, if a given symbol has BTF, (e.g. kfree_rcu_batch_init) it works. > > > kfree_on_online > > maybe_kfree_parameter > > trace_event_raw_rcu_invoke_kfree_bulk_callback > > trace_event_data_offsets_rcu_invoke_kfree_bulk_callback > > btf_trace_rcu_invoke_kfree_bulk_callback > > early_boot_kfree_rcu > > __bpf_trace_rcu_invoke_kfree_bulk_callback > > perf_trace_rcu_invoke_kfree_bulk_callback > > trace_event_raw_event_rcu_invoke_kfree_bulk_callback > > trace_raw_output_rcu_invoke_kfree_bulk_callback > > __probestub_rcu_invoke_kfree_bulk_callback > > __traceiter_rcu_invoke_kfree_bulk_callback > > kfree_rcu_cpu_work > > kfree_rcu_cpu > > kfree_rcu_batch_init > > kfree_rcu_scheduler_running > > kfree_rcu_shrink_scan > > kfree_rcu_shrink_count > > kfree_rcu_monitor > > kfree_rcu_work > > > > > > Here is the gcc version which I'm using. > > > > gcc version 11.3.0 (Ubuntu 11.3.0-1ubuntu1~22.04.1) > > I tried with gcc (GCC) 13.1.1 20230614 (Red Hat 13.1.1-4) > and latest pahole (master branch) Curiously, with Clang 16.0.0, it works (but many different errors are shown, see below *). So the combination of gcc/clang and pahole version can affect it. > > > > > I also attached the kernel config file. > > > > What is the recommended combination of the tools? > > Should I use Clang to build the kernel for BTF? > > should work fine with both gcc and clang And I guess it depends on compiler version, doesn't it? Thank you, (*) BTF .btf.vmlinux.bin.o die__process_unit: DW_TAG_label (0xa) @ <0x4b138> not handled! die__process_unit: tag not supported 0xa (label)! die__process_unit: DW_TAG_label (0xa) @ <0x4b241> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4b263> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4b290> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4b2c0> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4b2eb> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4b317> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4b33a> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4b35a> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4b37d> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4b39e> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4b3c4> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4b3e7> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4b40f> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4b435> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4b457> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4b477> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4b4a5> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4b4d5> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4b505> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4b530> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4b560> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4b585> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4b5b2> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4b5d9> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4b605> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4b62e> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4b652> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4b670> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4b694> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4b6b3> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4b6d9> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4b705> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4b72b> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4b753> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4b77f> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4b7b3> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4b7e4> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4b811> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4b83c> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4b869> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4b88c> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4b8bd> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4b8e7> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4b90b> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4b930> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4b960> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4b997> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4b9ce> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4ba00> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4ba24> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4ba4d> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4ba89> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4babc> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4bae4> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4bb0b> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4bb2e> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4bb4e> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4bb6d> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4bb8a> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4bba8> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4bbc5> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4bbe1> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4bc01> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4bc1c> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4bc38> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4bc58> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4bc79> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4bc95> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4bcb2> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x7efd6> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x7effe> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x7f11c> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x7f143> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x7f178> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x7f1a4> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x7f1ca> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x7f1fb> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x7f22f> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x7f25a> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x7f28d> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x7f2b7> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x1eea81> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x1eea9d> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x1eeac3> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x1eeaf3> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x1eeb0f> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x1eeb30> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x1eeb59> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x340734> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4c6b4a> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4c6b67> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4c6b8a> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4c6ba5> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4c6bc4> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4c6bea> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4c6c07> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4c6c2a> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4c6c4e> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4c6c79> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4c6c9b> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4c6cc3> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4c6ceb> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x4c6d15> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x30626ac> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x30626cd> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x3062814> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x3062833> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x3062b8b> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f623f6> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f62416> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f62437> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f62458> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f6280b> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f62b09> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f62b37> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f62c45> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f62c60> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f62d69> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f62e8d> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f6305a> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f63ec2> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f63edf> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f63efc> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f63f19> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f63f36> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f63f5b> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f63f80> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f63fa5> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f63fca> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f6fcae> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f6fcc7> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f6fed7> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f6fef0> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f6fdcb> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f70352> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f7036f> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f70394> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f703b1> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f703d6> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f703f3> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f70418> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f70435> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f7045a> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f7057b> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f705a6> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f705cf> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f705f8> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f70621> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f7064a> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f70673> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f7069c> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f706c5> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f706ee> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f70716> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f7073e> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f70767> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f70790> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f707b9> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f707e2> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f7080b> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f70834> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f70864> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f70892> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f708c0> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f708ee> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f7091c> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f7094a> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f70978> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f709a6> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f709d4> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f70a01> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f70a2e> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f70a5c> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f70a8a> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f70ab8> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f70ae6> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f70b14> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f70b42> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f70b72> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f70ba0> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f70bce> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f70bfc> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f70c2a> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f70c58> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f70c86> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f70cb4> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f70ce2> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f70d0f> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f70d3c> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f70d6a> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f70d98> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f70dc6> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f70df4> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f70e22> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f70e50> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f70e71> not handled! die__process_unit: DW_TAG_label (0xa) @ <0x5f70e94> not handled! LD .tmp_vmlinux.kallsyms1 > > jirka > > > > > Thank you, > > > > -- > > Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx> > > -- Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>
