From: Florent Revest <revest@chromium.org>
To: bpf@vger.kernel.org
Cc: ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org,
kpsingh@chromium.org, linux-kernel@vger.kernel.org,
Florent Revest <revest@chromium.org>,
KP Singh <kpsingh@kernel.org>
Subject: [PATCH bpf-next v6 4/5] selftests/bpf: Use vmlinux.h in socket_cookie_prog.c
Date: Tue, 26 Jan 2021 19:35:58 +0100 [thread overview]
Message-ID: <20210126183559.1302406-4-revest@chromium.org> (raw)
In-Reply-To: <20210126183559.1302406-1-revest@chromium.org>
When migrating from the bpf.h's to the vmlinux.h's definition of struct
bps_sock, an interesting LLVM behavior happened. LLVM started producing
two fetches of ctx->sk in the sockops program this means that the
verifier could not keep track of the NULL-check on ctx->sk. Therefore,
we need to extract ctx->sk in a variable before checking and
dereferencing it.
Acked-by: KP Singh <kpsingh@kernel.org>
Signed-off-by: Florent Revest <revest@chromium.org>
---
.../testing/selftests/bpf/progs/socket_cookie_prog.c | 11 ++++++-----
1 file changed, 6 insertions(+), 5 deletions(-)
diff --git a/tools/testing/selftests/bpf/progs/socket_cookie_prog.c b/tools/testing/selftests/bpf/progs/socket_cookie_prog.c
index 81e84be6f86d..fbd5eaf39720 100644
--- a/tools/testing/selftests/bpf/progs/socket_cookie_prog.c
+++ b/tools/testing/selftests/bpf/progs/socket_cookie_prog.c
@@ -1,12 +1,13 @@
// SPDX-License-Identifier: GPL-2.0
// Copyright (c) 2018 Facebook
-#include <linux/bpf.h>
-#include <sys/socket.h>
+#include "vmlinux.h"
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_endian.h>
+#define AF_INET6 10
+
struct socket_cookie {
__u64 cookie_key;
__u32 cookie_value;
@@ -41,7 +42,7 @@ int set_cookie(struct bpf_sock_addr *ctx)
SEC("sockops")
int update_cookie(struct bpf_sock_ops *ctx)
{
- struct bpf_sock *sk;
+ struct bpf_sock *sk = ctx->sk;
struct socket_cookie *p;
if (ctx->family != AF_INET6)
@@ -50,10 +51,10 @@ int update_cookie(struct bpf_sock_ops *ctx)
if (ctx->op != BPF_SOCK_OPS_TCP_CONNECT_CB)
return 1;
- if (!ctx->sk)
+ if (!sk)
return 1;
- p = bpf_sk_storage_get(&socket_cookies, ctx->sk, 0, 0);
+ p = bpf_sk_storage_get(&socket_cookies, sk, 0, 0);
if (!p)
return 1;
--
2.30.0.280.ga3ce27912f-goog
next prev parent reply other threads:[~2021-01-27 1:51 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-26 18:35 [PATCH bpf-next v6 1/5] bpf: Be less specific about socket cookies guarantees Florent Revest
2021-01-26 18:35 ` [PATCH bpf-next v6 2/5] bpf: Expose bpf_get_socket_cookie to tracing programs Florent Revest
2021-01-27 21:01 ` Andrii Nakryiko
2021-01-30 11:35 ` Florent Revest
[not found] ` <4a8ceab1-6eef-9fda-0502-5a0550f53ddc@iogearbox.net>
[not found] ` <37730136-2c33-589c-a749-4221b60b9751@iogearbox.net>
2021-01-30 11:45 ` Florent Revest
2021-02-01 22:32 ` Daniel Borkmann
2021-02-01 22:37 ` Alexei Starovoitov
2021-02-10 11:10 ` Florent Revest
2021-01-26 18:35 ` [PATCH bpf-next v6 3/5] selftests/bpf: Integrate the socket_cookie test to test_progs Florent Revest
2021-01-27 20:58 ` Andrii Nakryiko
2021-01-26 18:35 ` Florent Revest [this message]
2021-01-27 20:57 ` [PATCH bpf-next v6 4/5] selftests/bpf: Use vmlinux.h in socket_cookie_prog.c Andrii Nakryiko
2021-01-26 18:35 ` [PATCH bpf-next v6 5/5] selftests/bpf: Add a selftest for the tracing bpf_get_socket_cookie Florent Revest
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=20210126183559.1302406-4-revest@chromium.org \
--to=revest@chromium.org \
--cc=andrii@kernel.org \
--cc=ast@kernel.org \
--cc=bpf@vger.kernel.org \
--cc=daniel@iogearbox.net \
--cc=kpsingh@chromium.org \
--cc=kpsingh@kernel.org \
--cc=linux-kernel@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).