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From: Johannes Berg <johannes@sipsolutions.net>
To: Daniel Borkmann <daniel@iogearbox.net>
Cc: "netdev@vger.kernel.org" <netdev@vger.kernel.org>,
	Alexei Starovoitov <ast@kernel.org>
Subject: Re: eBPF - little-endian load instructions?
Date: Wed, 12 Apr 2017 15:02:00 +0200	[thread overview]
Message-ID: <1492002120.2855.3.camel@sipsolutions.net> (raw)
In-Reply-To: <58ECB8CF.8040409@iogearbox.net>

On Tue, 2017-04-11 at 13:06 +0200, Daniel Borkmann wrote:
> 
> There are instructions to convert endianess, see __bpf_prog_run(),
> the ALU_END_TO_BE, ALU_END_TO_LE labels for details. There's a
> BPF_ENDIAN() macro used in the test suite and other places.

Are these hooked up to llvm intrinsics or so? If not, can I do that
through some kind of inline asm statement?

In the samples, I only see people doing

#define _htonl __builtin_bswap32

but I'm not even completely convinced that's correct, since it assumes
a little-endian host?

johannes

  parent reply	other threads:[~2017-04-12 13:02 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-04-11 10:38 eBPF - little-endian load instructions? Johannes Berg
2017-04-11 11:06 ` Daniel Borkmann
2017-04-11 11:15   ` Johannes Berg
2017-04-11 11:22     ` Daniel Borkmann
2017-04-11 11:26       ` Johannes Berg
2017-04-12 13:02   ` Johannes Berg [this message]
2017-04-12 16:58     ` Alexei Starovoitov
2017-04-12 19:38       ` Johannes Berg
2017-04-13  3:08         ` Alexei Starovoitov
2017-04-13  5:58           ` Johannes Berg
2017-04-14 18:42             ` Alexei Starovoitov
2017-04-15  7:06               ` Johannes Berg

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