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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: Florent Revest <revest@chromium.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: KP Singh <kpsingh@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210210111406.785541-4-revest@chromium.org
This commit is contained in:
Florent Revest 2021-02-10 12:14:05 +01:00 committed by Alexei Starovoitov
parent 61f8c9c8f3
commit 6cd4dcc3fb
1 changed files with 6 additions and 5 deletions
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11
tools/testing/selftests/bpf/progs/socket_cookie_prog.c
View File

@ -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;