From: Yaniv Agman <yanivagman@gmail.com>
To: Daniel Borkmann <daniel@iogearbox.net>
Cc: bpf <bpf@vger.kernel.org>,
Andrii Nakryiko <andrii.nakryiko@gmail.com>,
Yonghong Song <yhs@fb.com>
Subject: Re: libbpf error: unknown register name 'r0' in asm
Date: Fri, 9 Oct 2020 19:56:57 +0300 [thread overview]
Message-ID: <CAMy7=ZXjna6q53h0uuar58fmAMi026w7u=ciVjTQXK2OHiOPJg@mail.gmail.com> (raw)
In-Reply-To: <a8abb367-ccad-2ee4-8c5e-ce3da7c4915d@iogearbox.net>
בתאריך יום ו׳, 9 באוק׳ 2020 ב-19:27 מאת Daniel Borkmann
<daniel@iogearbox.net>:
>
> [ Cc +Yonghong ]
>
> On 10/9/20 6:05 PM, Yaniv Agman wrote:
> > Pulling the latest changes of libbpf and compiling my application with it,
> > I see the following error:
> >
> > ../libbpf/src//root/usr/include/bpf/bpf_helpers.h:99:10: error:
> > unknown register name 'r0' in asm
> > : "r0", "r1", "r2", "r3", "r4", "r5");
> >
> > The commit which introduced this change is:
> > 80c7838600d39891f274e2f7508b95a75e4227c1
> >
> > I'm not sure if I'm doing something wrong (missing include?), or this
> > is a genuine error
>
> Seems like your clang/llvm version might be too old.
I'm using clang 10.0.1
>
> Yonghong, do you happen to know from which version onwards there is proper support
> for bpf inline asm? We could potentially wrap this around like this:
>
> diff --git a/tools/lib/bpf/bpf_helpers.h b/tools/lib/bpf/bpf_helpers.h
> index 2bdb7d6dbad2..0d6abc91bfc6 100644
> --- a/tools/lib/bpf/bpf_helpers.h
> +++ b/tools/lib/bpf/bpf_helpers.h
> @@ -72,6 +72,7 @@
> /*
> * Helper function to perform a tail call with a constant/immediate map slot.
> */
> +#if __clang_major__ >= 10
> static __always_inline void
> bpf_tail_call_static(void *ctx, const void *map, const __u32 slot)
> {
> @@ -98,6 +99,7 @@ bpf_tail_call_static(void *ctx, const void *map, const __u32 slot)
> :: [ctx]"r"(ctx), [map]"r"(map), [slot]"i"(slot)
> : "r0", "r1", "r2", "r3", "r4", "r5");
> }
> +#endif /* __clang_major__ >= 10 */
>
> /*
> * Helper structure used by eBPF C program
>
>
>
> > Yaniv
> >
>
next prev parent reply other threads:[~2020-10-09 16:57 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-09 16:05 libbpf error: unknown register name 'r0' in asm Yaniv Agman
2020-10-09 16:27 ` Daniel Borkmann
2020-10-09 16:56 ` Yaniv Agman [this message]
2020-10-09 17:39 ` Daniel Borkmann
2020-10-09 18:09 ` Yaniv Agman
2020-10-09 18:21 ` Daniel Borkmann
2020-10-09 18:33 ` Yaniv Agman
2020-10-09 18:39 ` Andrii Nakryiko
2020-10-09 19:32 ` Yaniv Agman
2020-10-09 19:53 ` Andrii Nakryiko
2020-10-09 20:24 ` Yaniv Agman
2020-10-12 20:03 ` Andrii Nakryiko
2020-10-12 21:48 ` Yaniv Agman
2020-10-12 22:16 ` Andrii Nakryiko
2020-10-09 18:35 ` Andrii Nakryiko
2020-10-09 18:41 ` Daniel Borkmann
2020-10-09 18:59 ` Andrii Nakryiko
2020-10-09 19:08 ` Yonghong Song
2020-10-09 19:33 ` Yaniv Agman
2020-10-09 19:58 ` Daniel Borkmann
2020-10-21 9:43 ` Yaniv Agman
2020-10-21 17:18 ` Daniel Borkmann
2020-10-21 19:33 ` Yaniv Agman
2020-10-09 17:41 ` Yonghong Song
2020-10-09 18:03 ` Andrii Nakryiko
2020-10-09 18:12 ` Yaniv Agman
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to='CAMy7=ZXjna6q53h0uuar58fmAMi026w7u=ciVjTQXK2OHiOPJg@mail.gmail.com' \
--to=yanivagman@gmail.com \
--cc=andrii.nakryiko@gmail.com \
--cc=bpf@vger.kernel.org \
--cc=daniel@iogearbox.net \
--cc=yhs@fb.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).