Commit 6cd4dcc3 authored by Florent Revest's avatar Florent Revest Committed by Alexei Starovoitov
Browse files

selftests/bpf: Use vmlinux.h in socket_cookie_prog.c 



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.

Signed-off-by: default avatarFlorent Revest <revest@chromium.org>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Acked-by: default avatarKP Singh <kpsingh@kernel.org>
Acked-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210210111406.785541-4-revest@chromium.org
parent 61f8c9c8

tools/testing/selftests/bpf/progs/socket_cookie_prog.c

+6 −5
Original line number Diff line number Diff line 
// 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;