Oops, sorry about my terrible formatting.
On Mon, Oct 26, 2020 at 2:17 PM Hao Luo <haoluo@xxxxxxxxxx> wrote:
>
> On Mon, Oct 26, 2020 at 1:32 PM Jiri Olsa <jolsa@xxxxxxxxxx> wrote:
> >
> > On Mon, Oct 26, 2020 at 04:58:30PM -0300, Arnaldo Carvalho de Melo wrote:
> > > Hi guys,
> > >
> > > I just stumbled on this, investigating... This is with what is
> > > in the tmp branch at
> > > git://git.kernel.org/pub/scm/devel/pahole/pahole.git.
> > >
> > > error: found variable in CU '/home/acme/git/linux/security/selinux/hooks.c' that has void type
> > > Encountered error while encoding BTF.
> > > 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
> > > FAILED: load BTF from vmlinux: Unknown error -2make[1]: *** [/home/acme/git/linux/Makefile:1164: vmlinux] Error 255
> > > make[1]: Leaving directory '/home/acme/git/build/v5.10.0-rc1+'
> > > make: *** [Makefile:185: __sub-make] Error 2
> >
> > yep, I see the same and when I use --btf_encode_force,
> > it shows more of them:
> >
> > error: found variable in CU 'arch/x86/kernel/cpu/mce/core.c' that has void type
> > error: found variable in CU 'security/selinux/hooks.c' that has void type
> > error: found variable in CU 'security/selinux/hooks.c' that has void type
> > error: found variable in CU 'security/selinux/hooks.c' that has void type
> > error: found variable in CU 'security/selinux/hooks.c' that has void type
> > error: found variable in CU 'security/selinux/hooks.c' that has void type
> > error: found variable in CU 'security/selinux/hooks.c' that has void type
> > error: found variable in CU 'drivers/platform/x86/intel_pmc_core.c' that has void type
> >
> > I have no idea how variables are encoded in dwarf,
> > but I wonder it's another gcc bug ;-)
> >
> > jirka
> >
>
> Still looking. But I found if I move
>
> c815d266 (Hao Luo 2020-08-24 17:45:23 -0700 444)
> if (var->ip.tag.type == 0) {
> 2e719cca (Andrii Nakryiko 2020-10-08 16:39:57 -0700 445)
> fprintf(stderr, "error: found variable in CU '%s'
> that has void type\n",
> 2e719cca (Andrii Nakryiko 2020-10-08 16:39:57 -0700 446)
> cu->name);
> f3d9054b (Hao Luo 2020-07-08 13:44:10 -0700 447)
> if (force)
> f3d9054b (Hao Luo 2020-07-08 13:44:10 -0700 448)
> continue;
> f3d9054b (Hao Luo 2020-07-08 13:44:10 -0700 449)
> err = -1;
> f3d9054b (Hao Luo 2020-07-08 13:44:10 -0700 450)
> break;
> f3d9054b (Hao Luo 2020-07-08 13:44:10 -0700 451)
> }
> f3d9054b (Hao Luo 2020-07-08 13:44:10 -0700 452)
>
> after
>
> 2e719cca (Andrii Nakryiko 2020-10-08 16:39:57 -0700 453)
> type = var->ip.tag.type + type_id_off;
> 2e719cca (Andrii Nakryiko 2020-10-08 16:39:57 -0700 454)
> linkage = var->external ? BTF_VAR_GLOBAL_ALLOCATED :
> BTF_VAR_STATIC;
> 2e719cca (Andrii Nakryiko 2020-10-08 16:39:57 -0700 455)
> if (!percpu_var_exists(addr, &size, &name))
> 2e719cca (Andrii Nakryiko 2020-10-08 16:39:57 -0700 456)
> continue; /* not a per-CPU variable */
>
> the error is gone. I think we should check percpu_var_exists() before
> checking var->ip.tag.type.
>
> Hao
