Re: ANNOUNCE: pahole v1.23 (BTF tags and alignment inference)

Arnaldo Carvalho de Melo
2021-12-17T19:12:20Z

Em Tue, Dec 14, 2021 at 02:56:16PM -0700, Nathan Chancellor escreveu:
> Hi Arnaldo,
>
> On Wed, Dec 08, 2021 at 10:54:56AM -0300, Arnaldo Carvalho de Melo wrote:
> > - Initial support for DW_TAG_skeleton_unit, so far just suggest looking up a
> > matching .dwo file to be used instead. Automagically doing this is in the
> > plans for a future release.
>
> This change [1] appears to break building on older distributions for me,
> which I use in containers for access to older versions of GCC. I see the
> error with Debian Stretch and Ubuntu Xenial, which have an older
> libelf-dev. Is this expected? I don't mind sticking with 1.22 for
> those, I just want to be sure!
>
> /tmp/dwarves-1.23/dwarf_loader.c: In function 'die__process':
> /tmp/dwarves-1.23/dwarf_loader.c:2529:13: error: 'DW_TAG_skeleton_unit' undeclared (first use in this function)
> if (tag == DW_TAG_skeleton_unit) {
> ^
>
> [1]: https://git.kernel.org/pub/scm/devel/pahole/pahole.git/commit/?id=0135ccd632796ab3aff65b7c99b374c4682c2bcf
>

with the following patch:

commit 2f7d61b2bfb59427926867c886595ff28dd50607
Author: Arnaldo Carvalho de Melo <acme@redhat.com>
Date: Fri Dec 17 15:50:17 2021 -0300

core: Define DW_TAG_skeleton_unit if not available on current dwarf.h

We use this in both the dwarf_loader.c and in fprintf.c, so define it in
dwarves.h that is included in both.

Reported-by: Nathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/all/YbkTAPn3EEu6BUYR@archlinux-ax161
Cc: Domenico Andreoli <domenico.andreoli@linux.com>
Cc: Douglas RAILLARD <douglas.raillard@arm.com>
Cc: Ilya Leoshkevich <iii@linux.ibm.com>
Cc: Jan Engelhardt <jengelh@inai.de>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Matteo Croce <mcroce@microsoft.com>
Cc: Matthias Schwarzott <zzam@gentoo.org>
Cc: Yonghong Song <yhs@fb.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/dwarves.h b/dwarves.h
index 52d162d67456bf12..2132da0ef02b78fd 100644
--- a/dwarves.h
+++ b/dwarves.h
@@ -1390,4 +1390,8 @@ extern bool no_bitfield_type_recode;

extern const char tabs[];

+#ifndef DW_TAG_skeleton_unit
+#define DW_TAG_skeleton_unit 0x4a
+#endif
+
#endif /* _DWARVES_H_ */

And using the perf build containers to build with both gcc and clang
only a few older distros are failing, I'll make buildcmd.sh, that is in
the dwarves repo, to build using the system libbpf-devel (or equivalent)
package and have this running after processing patches as I did for 1.22
but forgot to do for 1.23 :-/

- Arnaldo

[perfbuilder@five ~]$ export BUILD_TARBALL=http://192.168.100.2/pahole/dwarves-1.24.tar.xz
[perfbuilder@five ~]$ export BUILD_CMD=buildcmd.sh
[perfbuilder@five ~]$ time dm -X
1 3.67 almalinux:8 : Ok gcc (GCC) 8.5.0 20210514 (Red Hat 8.5.0-4) , clang version 12.0.1 (Red Hat 12.0.1-4.module_el8.5.0+1025+93159d6c)
2 0.96 alpine:3.4 : FAIL gcc version 5.3.0 (Alpine 5.3.0)

3 0.96 alpine:3.5 : FAIL gcc version 6.2.1 20160822 (Alpine 6.2.1)

4 1.06 alpine:3.6 : FAIL gcc version 6.3.0 (Alpine 6.3.0)

5 1.06 alpine:3.7 : FAIL gcc version 6.4.0 (Alpine 6.4.0)

6 0.96 alpine:3.8 : FAIL gcc version 6.4.0 (Alpine 6.4.0)

7 0.86 alpine:3.9 : FAIL gcc version 8.3.0 (Alpine 8.3.0)

8 1.06 alpine:3.10 : FAIL gcc version 8.3.0 (Alpine 8.3.0)

9 0.76 alpine:3.11 : FAIL gcc version 9.3.0 (Alpine 9.3.0)

10 4.47 alpine:3.12 : Ok gcc (Alpine 9.3.0) 9.3.0 , Alpine clang version 10.0.0 (https://gitlab.alpinelinux.org/alpine/aports.git 7445adce501f8473efdb93b17b5eaf2f1445ed4c)
11 4.87 alpine:3.13 : Ok gcc (Alpine 10.2.1_pre1) 10.2.1 20201203 , Alpine clang version 10.0.1
12 4.87 alpine:3.14 : Ok gcc (Alpine 10.3.1_git20210424) 10.3.1 20210424 , Alpine clang version 11.1.0
13 4.77 alpine:3.15 : Ok gcc (Alpine 10.3.1_git20211027) 10.3.1 20211027 , Alpine clang version 12.0.1
14 5.07 alpine:edge : Ok gcc (Alpine 11.2.1_git20211128) 11.2.1 20211128 , Alpine clang version 12.0.1
15 3.27 alt:p8 : Ok x86_64-alt-linux-gcc (GCC) 5.3.1 20151207 (ALT p8 5.3.1-alt3.M80P.1) , clang version 3.8.0 (tags/RELEASE_380/final)
16 3.66 alt:p9 : Ok x86_64-alt-linux-gcc (GCC) 8.4.1 20200305 (ALT p9 8.4.1-alt0.p9.1) , clang version 10.0.0
17 3.57 alt:p10 : Ok x86_64-alt-linux-gcc (GCC) 10.3.1 20210703 (ALT Sisyphus 10.3.1-alt2) , clang version 11.0.1
18 3.66 alt:sisyphus : Ok x86_64-alt-linux-gcc (GCC) 11.2.1 20210911 (ALT Sisyphus 11.2.1-alt1) , ALT Linux Team clang version 12.0.1
19 3.16 amazonlinux:1 : Ok gcc (GCC) 7.2.1 20170915 (Red Hat 7.2.1-2) , clang version 3.6.2 (tags/RELEASE_362/final)
20 3.26 amazonlinux:2 : Ok gcc (GCC) 7.3.1 20180712 (Red Hat 7.3.1-13) , clang version 11.1.0 (Amazon Linux 2 11.1.0-1.amzn2.0.2)
21 3.46 centos:8 : Ok gcc (GCC) 8.4.1 20200928 (Red Hat 8.4.1-1) , clang version 11.0.1 (Red Hat 11.0.1-1.module_el8.4.0+966+2995ef20)
22 3.46 centos:stream : Ok gcc (GCC) 8.5.0 20210514 (Red Hat 8.5.0-3) , clang version 12.0.1 (Red Hat 12.0.1-2.module_el8.6.0+937+1cafe22c)
23 3.57 clearlinux:latest : Ok gcc (Clear Linux OS for Intel Architecture) 11.2.1 20211208 releases/gcc-11.2.0-562-gbd918acae2 , clang version 11.1.0
24 3.77 debian:9 : Ok gcc (Debian 6.3.0-18+deb9u1) 6.3.0 20170516 , clang version 3.8.1-24 (tags/RELEASE_381/final)
25 3.67 debian:10 : Ok gcc (Debian 8.3.0-6) 8.3.0 , clang version 7.0.1-8+deb10u2 (tags/RELEASE_701/final)
26 3.67 debian:11 : Ok gcc (Debian 10.2.1-6) 10.2.1 20210110 , Debian clang version 11.0.1-2
27 3.87 debian:experimental : Ok gcc (Debian 11.2.0-12) 11.2.0 , Debian clang version 13.0.0-9+b1
28 3.16 fedora:22 : Ok gcc (GCC) 5.3.1 20160406 (Red Hat 5.3.1-6) , clang version 3.5.0 (tags/RELEASE_350/final)
29 3.46 fedora:23 : Ok gcc (GCC) 5.3.1 20160406 (Red Hat 5.3.1-6) , clang version 3.7.0 (tags/RELEASE_370/final)
30 3.47 fedora:24 : Ok gcc (GCC) 6.3.1 20161221 (Red Hat 6.3.1-1) , clang version 3.8.1 (tags/RELEASE_381/final)
31 3.48 fedora:25 : Ok gcc (GCC) 6.4.1 20170727 (Red Hat 6.4.1-1) , clang version 3.9.1 (tags/RELEASE_391/final)
32 3.67 fedora:26 : Ok gcc (GCC) 7.3.1 20180130 (Red Hat 7.3.1-2) , clang version 4.0.1 (tags/RELEASE_401/final)
33 3.46 fedora:27 : Ok gcc (GCC) 7.3.1 20180712 (Red Hat 7.3.1-6) , clang version 5.0.2 (tags/RELEASE_502/final)
34 3.87 fedora:28 : Ok gcc (GCC) 8.3.1 20190223 (Red Hat 8.3.1-2) , clang version 6.0.1 (tags/RELEASE_601/final)
35 3.87 fedora:29 : Ok gcc (GCC) 8.3.1 20190223 (Red Hat 8.3.1-2) , clang version 7.0.1 (Fedora 7.0.1-6.fc29)
36 3.67 fedora:30 : Ok gcc (GCC) 9.3.1 20200408 (Red Hat 9.3.1-2) , clang version 8.0.0 (Fedora 8.0.0-3.fc30)
37 3.56 fedora:31 : Ok gcc (GCC) 9.3.1 20200408 (Red Hat 9.3.1-2) , clang version 9.0.1 (Fedora 9.0.1-4.fc31)
38 3.76 fedora:32 : Ok gcc (GCC) 10.3.1 20210422 (Red Hat 10.3.1-1) , clang version 10.0.1 (Fedora 10.0.1-3.fc32)
39 3.57 fedora:33 : Ok gcc (GCC) 10.3.1 20210422 (Red Hat 10.3.1-1) , clang version 11.0.0 (Fedora 11.0.0-3.fc33)
40 3.67 fedora:34 : Ok gcc (GCC) 11.2.1 20210728 (Red Hat 11.2.1-1) , clang version 12.0.1 (Fedora 12.0.1-1.fc34)
41 3.87 fedora:35 : Ok gcc (GCC) 11.2.1 20210728 (Red Hat 11.2.1-1) , clang version 13.0.0 (Fedora 13.0.0-3.fc35)
42 3.87 fedora:rawhide : Ok gcc (GCC) 11.2.1 20211203 (Red Hat 11.2.1-7) , clang version 13.0.0 (Fedora 13.0.0-5.fc36)
43 3.97 gentoo-stage3:latest : Ok gcc (Gentoo 11.2.0 p1) 11.2.0 , clang version 13.0.0
44 3.37 mageia:6 : Ok gcc (Mageia 5.5.0-1.mga6) 5.5.0 , clang version 3.9.1 (tags/RELEASE_391/final)
45 3.97 mageia:7 : Ok gcc (Mageia 8.4.0-1.mga7) 8.4.0 , clang version 8.0.0 (Mageia 8.0.0-1.mga7)
46 4.67 openmandriva:cooker : FAIL gcc version 11.2.0 20210728 (OpenMandriva) (GCC)

47 3.97 opensuse:15.0 : Ok gcc (SUSE Linux) 7.4.1 20190905 [gcc-7-branch revision 275407] , clang version 5.0.1 (tags/RELEASE_501/final 312548)
48 3.57 opensuse:15.1 : Ok gcc (SUSE Linux) 7.5.0 , clang version 7.0.1 (tags/RELEASE_701/final 349238)
49 3.46 opensuse:15.2 : Ok gcc (SUSE Linux) 7.5.0 , clang version 9.0.1
50 3.36 opensuse:15.3 : Ok gcc (SUSE Linux) 7.5.0 , clang version 11.0.1
51 3.97 opensuse:tumbleweed : Ok gcc (SUSE Linux) 11.2.1 20210816 [revision 056e324ce46a7924b5cf10f61010cf9dd2ca10e9] , clang version 13.0.0
52 3.57 oraclelinux:8 : Ok gcc (GCC) 8.5.0 20210514 (Red Hat 8.5.0-4.0.1) , clang version 12.0.1 (Red Hat 12.0.1-4.0.1.module+el8.5.0+20428+2b4ecd47)
53 3.67 rockylinux:8 : Ok gcc (GCC) 8.5.0 20210514 (Red Hat 8.5.0-4) , clang version 12.0.1 (Red Hat 12.0.1-4.module+el8.5.0+715+58f51d49)
54 3.47 ubuntu:16.04 : Ok gcc (Ubuntu 5.4.0-6ubuntu1~16.04.12) 5.4.0 20160609 , clang version 3.8.0-2ubuntu4 (tags/RELEASE_380/final)
55 3.67 ubuntu:18.04 : Ok gcc (Ubuntu 7.5.0-3ubuntu1~18.04) 7.5.0 , clang version 6.0.0-1ubuntu2 (tags/RELEASE_600/final)
56 3.97 ubuntu:20.04 : Ok gcc (Ubuntu 9.3.0-17ubuntu1~20.04) 9.3.0 , clang version 10.0.0-4ubuntu1
57 3.87 ubuntu:20.10 : Ok gcc (Ubuntu 10.3.0-1ubuntu1~20.10) 10.3.0 , Ubuntu clang version 11.0.0-2
58 3.57 ubuntu:21.04 : Ok gcc (Ubuntu 10.3.0-1ubuntu1) 10.3.0 , Ubuntu clang version 12.0.0-3ubuntu1~21.04.2
59 3.66 ubuntu:21.10 : Ok gcc (Ubuntu 11.2.0-7ubuntu2) 11.2.0 , Ubuntu clang version 13.0.0-2
60 199.605

real 4m55.822s
user 1m16.561s
sys 0m17.551s
[perfbuilder@five ~]$