netdev.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Eric Dumazet <edumazet@google.com>
To: "David S . Miller" <davem@davemloft.net>
Cc: netdev <netdev@vger.kernel.org>,
	Eric Dumazet <edumazet@google.com>,
	Eric Dumazet <eric.dumazet@gmail.com>,
	Daniel Borkmann <daniel@iogearbox.net>,
	Martin KaFai Lau <kafai@fb.com>,
	Alexei Starovoitov <ast@kernel.org>
Subject: [PATCH net] bpf: enforce correct alignment for instructions
Date: Wed, 20 Jun 2018 17:24:09 -0700	[thread overview]
Message-ID: <20180621002409.63136-1-edumazet@google.com> (raw)

After commit 9facc336876f ("bpf: reject any prog that failed read-only lock")
offsetof(struct bpf_binary_header, image) became 3 instead of 4,
breaking powerpc BPF badly, since instructions need to be word aligned.

Fixes: 9facc336876f ("bpf: reject any prog that failed read-only lock")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Martin KaFai Lau <kafai@fb.com>
Cc: Alexei Starovoitov <ast@kernel.org>
---
 include/linux/filter.h | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/include/linux/filter.h b/include/linux/filter.h
index b615df57b7d5b2ccb468c411c3a2aae103cd2aea..20f2659dd829256d7fef206087ab3262e1e291f5 100644
--- a/include/linux/filter.h
+++ b/include/linux/filter.h
@@ -472,7 +472,9 @@ struct sock_fprog_kern {
 struct bpf_binary_header {
 	u16 pages;
 	u16 locked:1;
-	u8 image[];
+
+	/* Some arches need word alignment for their instructions */
+	u8 image[] __aligned(4);
 };
 
 struct bpf_prog {
-- 
2.18.0.rc1.244.gcf134e6275-goog

             reply	other threads:[~2018-06-21  0:24 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-06-21  0:24 Eric Dumazet [this message]
2018-06-21  3:46 ` [PATCH net] bpf: enforce correct alignment for instructions David Miller
2018-06-21  4:08   ` Eric Dumazet
2018-06-21 21:03     ` Daniel Borkmann
2018-06-21 22:10       ` 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=20180621002409.63136-1-edumazet@google.com \
    --to=edumazet@google.com \
    --cc=ast@kernel.org \
    --cc=daniel@iogearbox.net \
    --cc=davem@davemloft.net \
    --cc=eric.dumazet@gmail.com \
    --cc=kafai@fb.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 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).