* btf_encoder: error: found variable in CU that has void type
@ 2020-10-26 20:10 Arnaldo Carvalho de Melo
2020-10-26 20:22 ` Arnaldo Carvalho de Melo
0 siblings, 1 reply; 3+ messages in thread
From: Arnaldo Carvalho de Melo @ 2020-10-26 20:10 UTC (permalink / raw)
To: Andrii Nakryiko, Hao Luo; +Cc: dwarves, Jiri Olsa
Now with a correct subject :-)
Em Mon, Oct 26, 2020 at 04:58:30PM -0300, Arnaldo Carvalho de Melo escreveu:
> 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
It is something recent:
c815d26689313d8d7 (Hao Luo 2020-08-24 17:45:23 -0700 440) if (var->ip.tag.type == 0) {
2e719cca667212840 (Andrii Nakryiko 2020-10-08 16:39:57 -0700 441) fprintf(stderr, "error: found variable in CU '%s' that has void type\n",
2e719cca667212840 (Andrii Nakryiko 2020-10-08 16:39:57 -0700 442) cu->name);
f3d9054ba8ff1df0f (Hao Luo 2020-07-08 13:44:10 -0700 443) if (force)
f3d9054ba8ff1df0f (Hao Luo 2020-07-08 13:44:10 -0700 444) continue;
f3d9054ba8ff1df0f (Hao Luo 2020-07-08 13:44:10 -0700 445) err = -1;
f3d9054ba8ff1df0f (Hao Luo 2020-07-08 13:44:10 -0700 446) break;
- Arnaldo
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: btf_encoder: error: found variable in CU that has void type
2020-10-26 20:10 btf_encoder: error: found variable in CU that has void type Arnaldo Carvalho de Melo
@ 2020-10-26 20:22 ` Arnaldo Carvalho de Melo
2020-10-26 21:42 ` Andrii Nakryiko
0 siblings, 1 reply; 3+ messages in thread
From: Arnaldo Carvalho de Melo @ 2020-10-26 20:22 UTC (permalink / raw)
To: Andrii Nakryiko, Hao Luo; +Cc: dwarves, Jiri Olsa
Em Mon, Oct 26, 2020 at 05:10:06PM -0300, Arnaldo Carvalho de Melo escreveu:
> Now with a correct subject :-)
>
> Em Mon, Oct 26, 2020 at 04:58:30PM -0300, Arnaldo Carvalho de Melo escreveu:
> > 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
>
> It is something recent:
>
> c815d26689313d8d7 (Hao Luo 2020-08-24 17:45:23 -0700 440) if (var->ip.tag.type == 0) {
> 2e719cca667212840 (Andrii Nakryiko 2020-10-08 16:39:57 -0700 441) fprintf(stderr, "error: found variable in CU '%s' that has void type\n",
> 2e719cca667212840 (Andrii Nakryiko 2020-10-08 16:39:57 -0700 442) cu->name);
> f3d9054ba8ff1df0f (Hao Luo 2020-07-08 13:44:10 -0700 443) if (force)
> f3d9054ba8ff1df0f (Hao Luo 2020-07-08 13:44:10 -0700 444) continue;
> f3d9054ba8ff1df0f (Hao Luo 2020-07-08 13:44:10 -0700 445) err = -1;
> f3d9054ba8ff1df0f (Hao Luo 2020-07-08 13:44:10 -0700 446) break;
Printing the variable name and address gives:
LD .tmp_vmlinux.btf
BTF .btf.vmlinux.bin.o
error: found variable "(null)" (addr: 0xffffffff82f4e260) in CU '/home/acme/git/linux/security/selinux/hooks.c' that has void type
Encountered error while encoding BTF.
Unsure if this is related:
[root@five ~]# gcc --version | head -1
gcc (GCC) 10.2.1 20200723 (Red Hat 10.2.1-1)
[root@five ~]#
[acme@five linux]$ readelf -sw ../build/v5.9.0+/vmlinux | grep ffffffff82f4e260
readelf: ../build/v5.9.0+/vmlinux: Error: LEB value too large
readelf: ../build/v5.9.0+/vmlinux: Error: LEB value too large
readelf: ../build/v5.9.0+/vmlinux: Error: LEB value too large
readelf: ../build/v5.9.0+/vmlinux: Error: LEB value too large
readelf: ../build/v5.9.0+/vmlinux: Error: LEB value too large
readelf: ../build/v5.9.0+/vmlinux: Error: LEB value too large
readelf: ../build/v5.9.0+/vmlinux: Error: LEB value too large
readelf: ../build/v5.9.0+/vmlinux: Error: LEB value too large
readelf: ../build/v5.9.0+/vmlinux: Error: LEB value too large
readelf: ../build/v5.9.0+/vmlinux: Error: LEB value too large
readelf: ../build/v5.9.0+/vmlinux: Error: LEB value too large
readelf: ../build/v5.9.0+/vmlinux: Error: LEB value too large
<SNIP lots more such lines>
- Arnaldo
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: btf_encoder: error: found variable in CU that has void type
2020-10-26 20:22 ` Arnaldo Carvalho de Melo
@ 2020-10-26 21:42 ` Andrii Nakryiko
0 siblings, 0 replies; 3+ messages in thread
From: Andrii Nakryiko @ 2020-10-26 21:42 UTC (permalink / raw)
To: Arnaldo Carvalho de Melo; +Cc: Andrii Nakryiko, Hao Luo, dwarves, Jiri Olsa
On Mon, Oct 26, 2020 at 1:22 PM Arnaldo Carvalho de Melo
<acme@kernel.org> wrote:
>
> Em Mon, Oct 26, 2020 at 05:10:06PM -0300, Arnaldo Carvalho de Melo escreveu:
> > Now with a correct subject :-)
> >
> > Em Mon, Oct 26, 2020 at 04:58:30PM -0300, Arnaldo Carvalho de Melo escreveu:
> > > 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
> >
> > It is something recent:
> >
> > c815d26689313d8d7 (Hao Luo 2020-08-24 17:45:23 -0700 440) if (var->ip.tag.type == 0) {
> > 2e719cca667212840 (Andrii Nakryiko 2020-10-08 16:39:57 -0700 441) fprintf(stderr, "error: found variable in CU '%s' that has void type\n",
> > 2e719cca667212840 (Andrii Nakryiko 2020-10-08 16:39:57 -0700 442) cu->name);
> > f3d9054ba8ff1df0f (Hao Luo 2020-07-08 13:44:10 -0700 443) if (force)
> > f3d9054ba8ff1df0f (Hao Luo 2020-07-08 13:44:10 -0700 444) continue;
> > f3d9054ba8ff1df0f (Hao Luo 2020-07-08 13:44:10 -0700 445) err = -1;
> > f3d9054ba8ff1df0f (Hao Luo 2020-07-08 13:44:10 -0700 446) break;
>
> Printing the variable name and address gives:
>
> LD .tmp_vmlinux.btf
> BTF .btf.vmlinux.bin.o
> error: found variable "(null)" (addr: 0xffffffff82f4e260) in CU '/home/acme/git/linux/security/selinux/hooks.c' that has void type
> Encountered error while encoding BTF.
>
> Unsure if this is related:
>
> [root@five ~]# gcc --version | head -1
> gcc (GCC) 10.2.1 20200723 (Red Hat 10.2.1-1)
> [root@five ~]#
>
> [acme@five linux]$ readelf -sw ../build/v5.9.0+/vmlinux | grep ffffffff82f4e260
> readelf: ../build/v5.9.0+/vmlinux: Error: LEB value too large
> readelf: ../build/v5.9.0+/vmlinux: Error: LEB value too large
> readelf: ../build/v5.9.0+/vmlinux: Error: LEB value too large
> readelf: ../build/v5.9.0+/vmlinux: Error: LEB value too large
> readelf: ../build/v5.9.0+/vmlinux: Error: LEB value too large
> readelf: ../build/v5.9.0+/vmlinux: Error: LEB value too large
> readelf: ../build/v5.9.0+/vmlinux: Error: LEB value too large
> readelf: ../build/v5.9.0+/vmlinux: Error: LEB value too large
> readelf: ../build/v5.9.0+/vmlinux: Error: LEB value too large
> readelf: ../build/v5.9.0+/vmlinux: Error: LEB value too large
> readelf: ../build/v5.9.0+/vmlinux: Error: LEB value too large
> readelf: ../build/v5.9.0+/vmlinux: Error: LEB value too large
>
> <SNIP lots more such lines>
>
Don't know what this is, but what Hao proposed (to check everything
only after we make sure that the variable has a proper per-CPU symbol
in ELF) would eliminate all that, so I think we should do just that.
But I'm surprised I didn't see any of those issues in my kernel
configurations and environment (though I use GCC 8, still, so that
might explain).
> - Arnaldo
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2020-10-26 21:42 UTC | newest]
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2020-10-26 20:10 btf_encoder: error: found variable in CU that has void type Arnaldo Carvalho de Melo
2020-10-26 20:22 ` Arnaldo Carvalho de Melo
2020-10-26 21:42 ` Andrii Nakryiko
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