On Mon, Oct 26, 2020 at 2:20 PM Hao Luo <haoluo@xxxxxxxxxx> wrote:
>
> 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.
sounds like a plan, can you please send a patch? Thanks!
> >
> > Hao
