On Thu, Jul 18, 2019 at 10:55 AM Arnaldo Carvalho de Melo
<arnaldo.melo@xxxxxxxxx> wrote:
>
> Em Thu, Jul 18, 2019 at 10:25:13AM -0700, Andrii Nakryiko escreveu:
> > hashmap.h depends on __WORDSIZE being defined. It is defined by
> > glibc/musl in different headers. It's an explicit goal for musl to be
> > "non-detectable" at compilation time, so instead include glibc header if
> > glibc is explicitly detected and fall back to musl header otherwise.
> >
> > Fixes: e3b924224028 ("libbpf: add resizable non-thread safe internal hashmap")
> > Reported-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
> > Signed-off-by: Andrii Nakryiko <andriin@xxxxxx>
>
> I fixed this here differently, as below, I didn't send it because I'm still
> testing it, so far, with a few other fixes and cherry-picking "libbpf: fix ptr
> to u64 conversion warning on 32-bit platforms" that is still in the bpf tree
> and is needed for the cross build containers in my suite that are 32-bit, I
> have the results below, this builds perf + libbpf (where elfutils is available,
> which is in most cases, except the uCLibc containers due to missing argp-devel),
> with gcc and with clang:
>
> [perfbuilder@quaco linux-perf-tools-build]$ export PERF_TARBALL=http://192.168.124.1/perf/perf-5.2.0.tar.xz
> [perfbuilder@quaco linux-perf-tools-build]$ time dm
> 1 alpine:3.4 : Ok gcc (Alpine 5.3.0) 5.3.0, clang version 3.8.0 (tags/RELEASE_380/final)
> 2 alpine:3.5 : Ok gcc (Alpine 6.2.1) 6.2.1 20160822, clang version 3.8.1 (tags/RELEASE_381/final)
> 3 alpine:3.6 : Ok gcc (Alpine 6.3.0) 6.3.0, clang version 4.0.0 (tags/RELEASE_400/final)
> 4 alpine:3.7 : Ok gcc (Alpine 6.4.0) 6.4.0, Alpine clang version 5.0.0 (tags/RELEASE_500/final) (based on LLVM 5.0.0)
> 5 alpine:3.8 : Ok gcc (Alpine 6.4.0) 6.4.0, Alpine clang version 5.0.1 (tags/RELEASE_501/final) (based on LLVM 5.0.1)
> 6 alpine:3.9 : Ok gcc (Alpine 8.3.0) 8.3.0, Alpine clang version 5.0.1 (tags/RELEASE_502/final) (based on LLVM 5.0.1)
> 7 alpine:3.10 : Ok gcc (Alpine 8.3.0) 8.3.0, Alpine clang version 8.0.0 (tags/RELEASE_800/final) (based on LLVM 8.0.0)
> 8 alpine:edge : Ok gcc (Alpine 8.3.0) 8.3.0, Alpine clang version 7.0.1 (tags/RELEASE_701/final) (based on LLVM 7.0.1)
> 9 amazonlinux:1 : Ok gcc (GCC) 7.2.1 20170915 (Red Hat 7.2.1-2), clang version 3.6.2 (tags/RELEASE_362/final)
> 10 amazonlinux:2 : Ok gcc (GCC) 7.3.1 20180303 (Red Hat 7.3.1-5), clang version 7.0.1 (Amazon Linux 2 7.0.1-1.amzn2.0.2)
> 11 android-ndk:r12b-arm : Ok arm-linux-androideabi-gcc (GCC) 4.9.x 20150123 (prerelease)
> 12 android-ndk:r15c-arm : Ok arm-linux-androideabi-gcc (GCC) 4.9.x 20150123 (prerelease)
> 13 centos:5 : Ok gcc (GCC) 4.1.2 20080704 (Red Hat 4.1.2-55)
> 14 centos:6 : Ok gcc (GCC) 4.4.7 20120313 (Red Hat 4.4.7-23)
> 15 centos:7 : Ok gcc (GCC) 4.8.5 20150623 (Red Hat 4.8.5-36), clang version 3.4.2 (tags/RELEASE_34/dot2-final)
> 16 clearlinux:latest : Ok gcc (Clear Linux OS for Intel Architecture) 9.1.1 20190628 gcc-9-branch@272773, clang version 8.0.0 (tags/RELEASE_800/final)
> 17 debian:8 : Ok gcc (Debian 4.9.2-10+deb8u2) 4.9.2, Debian clang version 3.5.0-10 (tags/RELEASE_350/final) (based on LLVM 3.5.0)
> 18 debian:9 : Ok gcc (Debian 6.3.0-18+deb9u1) 6.3.0 20170516, clang version 3.8.1-24 (tags/RELEASE_381/final)
> 19 debian:10 : Ok gcc (Debian 8.3.0-6) 8.3.0, clang version 7.0.1-8 (tags/RELEASE_701/final)
> 20 debian:experimental : Ok gcc (Debian 8.3.0-19) 8.3.0, clang version 7.0.1-8 (tags/RELEASE_701/final)
> 21 debian:experimental-x-arm64 : Ok aarch64-linux-gnu-gcc (Debian 8.3.0-19) 8.3.0
> 22 debian:experimental-x-mips : Ok mips-linux-gnu-gcc (Debian 8.3.0-19) 8.3.0
> 23 debian:experimental-x-mips64 : Ok mips64-linux-gnuabi64-gcc (Debian 8.3.0-7) 8.3.0
> 24 debian:experimental-x-mipsel : Ok mipsel-linux-gnu-gcc (Debian 8.3.0-19) 8.3.0
> 25 fedora:20 : Ok gcc (GCC) 4.8.3 20140911 (Red Hat 4.8.3-7), clang version 3.4.2 (tags/RELEASE_34/dot2-final)
> 26 fedora:22 : Ok gcc (GCC) 5.3.1 20160406 (Red Hat 5.3.1-6), clang version 3.5.0 (tags/RELEASE_350/final)
> 27 fedora:23 : Ok gcc (GCC) 5.3.1 20160406 (Red Hat 5.3.1-6), clang version 3.7.0 (tags/RELEASE_370/final)
> 28 fedora:24 : Ok gcc (GCC) 6.3.1 20161221 (Red Hat 6.3.1-1), clang version 3.8.1 (tags/RELEASE_381/final)
> 29 fedora:24-x-ARC-uClibc : Ok arc-linux-gcc (ARCompact ISA Linux uClibc toolchain 2017.09-rc2) 7.1.1 20170710
>
> I've pushed it to a tmp.perf/core branch in my
> git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux.git tree, that has
> these:
>
> d5e1f2d60d41 (HEAD -> perf/core, acme.korg/tmp.perf/core) libbpf: fix ptr to u64 conversion warning on 32-bit platforms
> 7c08fd16f917 tools lib bpf: Avoid designated initializers for unnamed union members
> 4c9f83c95ad6 tools lib bpf: Avoid using 'link' as it shadows a global definition in some systems
> bdb07df4a0ad tools lib bpf: Fix endianness macro usage for some compilers
> 66dbf3caff52 tools lib bpf: Replace __WORDSIZE with BITS_PER_LONG to build on the musl libc
>
> Please take a look and check if everything is fine on your side. The HEAD I'll
> remove if Daniel thinks it should wait that landing via the BPF tree, I just put it
> there for the test builds.
>
> commit 66dbf3caff52be0d004bcb9ac4cea4c19eb75dfc
> Author: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
> Date: Thu Jul 18 09:46:28 2019 -0300
>
> tools lib bpf: Replace __WORDSIZE with BITS_PER_LONG to build on the musl libc
>
> BITS_PER_LONG is more generally available and equivalent to __WORDSIZE,
> so use it instead to keep it building in systems using the mustl libc
> where __WORDSIZE is in a different place than in glibc.
>
> And do this by explicitely adding the header where this definition is
> (asm/bitsperlong.h) instead of getting it indirectly.
>
> Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
> Cc: Alexei Starovoitov <ast@xxxxxxxxxx>
> Cc: Andrii Nakryiko <andriin@xxxxxx>
> Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
> Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
> Fixes: e3b924224028 ("libbpf: add resizable non-thread safe internal hashmap")
> Link: https://lkml.kernel.org/n/tip-61vydgldzmmz5w2mf6rv3ryl@xxxxxxxxxxxxxx
> Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
>
> diff --git a/tools/lib/bpf/hashmap.h b/tools/lib/bpf/hashmap.h
> index 03748a742146..f1f37b574d9c 100644
> --- a/tools/lib/bpf/hashmap.h
> +++ b/tools/lib/bpf/hashmap.h
> @@ -10,12 +10,13 @@
>
> #include <stdbool.h>
> #include <stddef.h>
> +#include <asm/bitsperlong.h>
Relying on this header is problematic when syncing libbpf into Github
mirror. There we'll need to re-implement it anyway, and again,
probably through __WORDSIZE or some other tricks. So if we can do away
without kernel specific header that would be great.
> #include "libbpf_internal.h"
>
> static inline size_t hash_bits(size_t h, int bits)
> {
> /* shuffle bits and return requested number of upper bits */
> - return (h * 11400714819323198485llu) >> (__WORDSIZE - bits);
> + return (h * 11400714819323198485llu) >> (BITS_PER_LONG - bits);
> }
>
> typedef size_t (*hashmap_hash_fn)(const void *key, void *ctx);
