Re: [PATCH dwarves 0/2] dwarf_loader: improve cus__merging_cu()

[Arnaldo Carvalho de Melo <acme@kernel.org>]

Em Tue, Apr 06, 2021 at 02:34:01PM -0300, Arnaldo Carvalho de Melo escreveu:
> Em Tue, Apr 06, 2021 at 10:23:37AM -0700, Yonghong Song escreveu:
> > On 4/6/21 10:03 AM, Arnaldo Carvalho de Melo wrote:
> > > Em Tue, Apr 06, 2021 at 01:59:30PM -0300, Arnaldo Carvalho de Melo escreveu:
> > > > Em Tue, Apr 06, 2021 at 01:55:54PM -0300, Arnaldo Carvalho de Melo escreveu:
> > > > > Em Tue, Apr 06, 2021 at 01:40:20PM -0300, Arnaldo Carvalho de Melo escreveu:
> > > > > > Em Tue, Apr 06, 2021 at 10:22:37AM -0300, Arnaldo Carvalho de Melo escreveu:
> > > > > > > I'm seeing these here:
> > > > > 
> > > > > > > [acme@five bpf]$ rm -f ../build/bpf_clang_thin_lto/*vmlinu*
> > > > > > > [acme@five bpf]$ time make -j28 LLVM=1 LLVM_IAS=1 O=../build/bpf_clang_thin_lto/ vmlinux
> > > > > > > make[1]: Entering directory '/home/acme/git/build/bpf_clang_thin_lto'
> > > > > > >    GEN     Makefile
> > > > > > >    DESCEND  objtool
> > > > > > >    DESCEND  bpf/resolve_btfids
> > > > > > >    CALL    /home/acme/git/bpf/scripts/atomic/check-atomics.sh
> > > > > > >    CALL    /home/acme/git/bpf/scripts/checksyscalls.sh
> > > > > > >    CHK     include/generated/compile.h
> > > > > > >    GEN     .version
> > > > > > >    CHK     include/generated/compile.h
> > > > > > >    UPD     include/generated/compile.h
> > > > > > >    CC      init/version.o
> > > > > > >    AR      init/built-in.a
> > > > > > >    GEN     .tmp_initcalls.lds
> > > > > > >    LTO     vmlinux.o
> > > > > > >    OBJTOOL vmlinux.o
> > > > > > > vmlinux.o: warning: objtool: aesni_gcm_init_avx_gen2()+0x12: unsupported stack pointer realignment
> > > > > > > vmlinux.o: warning: objtool: aesni_gcm_enc_update_avx_gen2()+0x12: unsupported stack pointer realignment
> > > > > > > vmlinux.o: warning: objtool: aesni_gcm_dec_update_avx_gen2()+0x12: unsupported stack pointer realignment
> > > > > > > vmlinux.o: warning: objtool: aesni_gcm_finalize_avx_gen2()+0x12: unsupported stack pointer realignment
> > > > > > > vmlinux.o: warning: objtool: aesni_gcm_init_avx_gen4()+0x12: unsupported stack pointer realignment
> > > > > > > vmlinux.o: warning: objtool: aesni_gcm_enc_update_avx_gen4()+0x12: unsupported stack pointer realignment
> > > > > > > vmlinux.o: warning: objtool: aesni_gcm_dec_update_avx_gen4()+0x12: unsupported stack pointer realignment
> > > > > > > vmlinux.o: warning: objtool: aesni_gcm_finalize_avx_gen4()+0x12: unsupported stack pointer realignment
> > > > > > >    MODPOST vmlinux.symvers
> > > > > > >    MODINFO modules.builtin.modinfo
> > > > > > >    GEN     modules.builtin
> > > > > > >    LD      .tmp_vmlinux.btf
> > > > > > >    BTF     .btf.vmlinux.bin.o
> > > > > > >    LD      .tmp_vmlinux.kallsyms1
> > > > > > >    KSYMS   .tmp_vmlinux.kallsyms1.S
> > > > > > >    AS      .tmp_vmlinux.kallsyms1.S
> > > > > > >    LD      .tmp_vmlinux.kallsyms2
> > > > > > >    KSYMS   .tmp_vmlinux.kallsyms2.S
> > > > > > >    AS      .tmp_vmlinux.kallsyms2.S
> > > > > > >    LD      vmlinux
> > > > > > >    BTFIDS  vmlinux
> > > > > > > WARN: multiple IDs found for 'inode': 232, 28822 - using 232
> > > > > > > WARN: multiple IDs found for 'file': 374, 28855 - using 374
> > > > > > > WARN: multiple IDs found for 'path': 379, 28856 - using 379
> > > > > > > WARN: multiple IDs found for 'vm_area_struct': 177, 28929 - using 177
> > > > > > > WARN: multiple IDs found for 'task_struct': 97, 28966 - using 97
> > > > > > > WARN: multiple IDs found for 'seq_file': 510, 29059 - using 510
> > > > > > > WARN: multiple IDs found for 'inode': 232, 29345 - using 232
> > > > > > > WARN: multiple IDs found for 'file': 374, 29429 - using 374
> > > > > > > WARN: multiple IDs found for 'path': 379, 29430 - using 379
> > > > > > > WARN: multiple IDs found for 'vm_area_struct': 177, 29471 - using 177
> > > > > > > WARN: multiple IDs found for 'task_struct': 97, 29481 - using 97
> > > > > > > WARN: multiple IDs found for 'seq_file': 510, 29512 - using 510
> > > > > > >    SORTTAB vmlinux
> > > > > > >    SYSMAP  System.map
> > > > > > > make[1]: Leaving directory '/home/acme/git/build/bpf_clang_thin_lto'
> > > > > > > 
> > > > > > > [acme@five pahole]$ clang -v
> > > > > > > clang version 11.0.0 (Fedora 11.0.0-2.fc33)
> > 
> > This could be due to the compiler. The clang 11 is used here. Sedat is
> > using clang 12 and didn't see warnings and I am using clang dev branch

Cool, clang 12 is the one in Fedora 34 beta.

- Arnaldo

> > (clang 13) and didn't see warnings either. clang 11 could generate
> > some debuginfo where pahole didn't handle it properly.
> > 
> > I tried to build locally with clang 11 but it crashed as I enabled
> > assert during compiler build. Will try a little bit more.
> 
> Right, I'm now at:
> 
> $ git clone https://github.com/llvm/llvm-project.git
> $ cmake -DLLVM_ENABLE_PROJECTS=clang -G "Unix Makefiles" ../llvm