From: Daniel Borkmann <daniel@iogearbox.net>
To: Alexei Starovoitov <ast@fb.com>,
"David S . Miller" <davem@davemloft.net>
Cc: Gianluca Borello <g.borello@gmail.com>, netdev@vger.kernel.org
Subject: Re: [PATCH net-next] bpf: Preserve const register type on const OR alu ops
Date: Sun, 04 Dec 2016 00:41:59 +0100 [thread overview]
Message-ID: <58435847.2000406@iogearbox.net> (raw)
In-Reply-To: <1480797093-1050393-1-git-send-email-ast@fb.com>
On 12/03/2016 09:31 PM, Alexei Starovoitov wrote:
> From: Gianluca Borello <g.borello@gmail.com>
>
> Occasionally, clang (e.g. version 3.8.1) translates a sum between two
> constant operands using a BPF_OR instead of a BPF_ADD. The verifier is
> currently not handling this scenario, and the destination register type
> becomes UNKNOWN_VALUE even if it's still storing a constant. As a result,
> the destination register cannot be used as argument to a helper function
> expecting a ARG_CONST_STACK_*, limiting some use cases.
>
> Modify the verifier to handle this case, and add a few tests to make sure
> all combinations are supported, and stack boundaries are still verified
> even with BPF_OR.
>
> Signed-off-by: Gianluca Borello <g.borello@gmail.com>
> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
next prev parent reply other threads:[~2016-12-03 23:42 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-12-03 20:31 [PATCH net-next] bpf: Preserve const register type on const OR alu ops Alexei Starovoitov
2016-12-03 23:41 ` Daniel Borkmann [this message]
2016-12-05 18:41 ` 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=58435847.2000406@iogearbox.net \
--to=daniel@iogearbox.net \
--cc=ast@fb.com \
--cc=davem@davemloft.net \
--cc=g.borello@gmail.com \
--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.