From: Alexei Starovoitov <ast@plumgrid.com>
To: Daniel Borkmann <daniel@iogearbox.net>, davem@davemloft.net
Cc: netdev@vger.kernel.org
Subject: Re: [PATCH net-next v2] test_bpf: add similarly conflicting jump test case only for classic
Date: Tue, 26 May 2015 13:43:26 -0700 [thread overview]
Message-ID: <5564DAEE.9060108@plumgrid.com> (raw)
In-Reply-To: <81f8411227ef0e1829b2b9511094112c3f4f3ca5.1432671849.git.daniel@iogearbox.net>
On 5/26/15 1:35 PM, Daniel Borkmann wrote:
> While 3b52960266a3 ("test_bpf: add more eBPF jump torture cases")
> added the int3 bug test case only for eBPF, which needs exactly 11
> passes to converge, here's a version for classic BPF with 11 passes,
> and one that would need 70 passes on x86_64 to actually converge for
> being successfully JITed. Effectively, all jumps are being optimized
> out resulting in a JIT image of just 89 bytes (from originally max
> BPF insns), only returning K.
>
> Might be useful as a receipe for folks wanting to craft a test case
> when backporting the fix in commit 3f7352bf21f8 ("x86: bpf_jit: fix
> compilation of large bpf programs") while not having eBPF. The 2nd
> one is delegated to the interpreter as the last pass still results
> in shrinking, in other words, this one won't be JITed on x86_64.
>
> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
great tests. Thanks!
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
next prev parent reply other threads:[~2015-05-26 20:43 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-05-26 20:35 [PATCH net-next v2] test_bpf: add similarly conflicting jump test case only for classic Daniel Borkmann
2015-05-26 20:43 ` Alexei Starovoitov [this message]
2015-05-27 18:16 ` David Miller
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=5564DAEE.9060108@plumgrid.com \
--to=ast@plumgrid.com \
--cc=daniel@iogearbox.net \
--cc=davem@davemloft.net \
--cc=netdev@vger.kernel.org \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.