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git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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26a7cf2bbe
A new version of a type may have additional fields that do not exist in older versions. Previously, libbpf would reject struct_ops maps with a new version containing extra fields when running on a machine with an old kernel. However, we have updated libbpf to ignore these fields if their values are all zeros or null in order to provide backward compatibility. Signed-off-by: Kui-Feng Lee <thinker.li@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20240313214139.685112-3-thinker.li@gmail.com
70 lines
1.4 KiB
C
70 lines
1.4 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/* Copyright (c) 2024 Meta Platforms, Inc. and affiliates. */
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#include <vmlinux.h>
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#include <bpf/bpf_helpers.h>
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#include <bpf/bpf_tracing.h>
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#include "../bpf_testmod/bpf_testmod.h"
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char _license[] SEC("license") = "GPL";
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int test_1_result = 0;
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int test_2_result = 0;
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SEC("struct_ops/test_1")
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int BPF_PROG(test_1)
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{
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test_1_result = 0xdeadbeef;
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return 0;
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}
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SEC("struct_ops/test_2")
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void BPF_PROG(test_2, int a, int b)
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{
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test_2_result = a + b;
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}
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SEC("?struct_ops/test_3")
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int BPF_PROG(test_3, int a, int b)
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{
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test_2_result = a + b + 3;
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return a + b + 3;
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}
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SEC(".struct_ops.link")
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struct bpf_testmod_ops testmod_1 = {
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.test_1 = (void *)test_1,
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.test_2 = (void *)test_2,
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.data = 0x1,
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};
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SEC("struct_ops/test_2")
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void BPF_PROG(test_2_v2, int a, int b)
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{
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test_2_result = a * b;
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}
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struct bpf_testmod_ops___v2 {
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int (*test_1)(void);
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void (*test_2)(int a, int b);
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int (*test_maybe_null)(int dummy, struct task_struct *task);
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};
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SEC(".struct_ops.link")
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struct bpf_testmod_ops___v2 testmod_2 = {
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.test_1 = (void *)test_1,
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.test_2 = (void *)test_2_v2,
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};
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struct bpf_testmod_ops___zeroed {
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int (*test_1)(void);
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void (*test_2)(int a, int b);
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int (*test_maybe_null)(int dummy, struct task_struct *task);
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void (*zeroed_op)(int a, int b);
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int zeroed;
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};
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SEC(".struct_ops.link")
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struct bpf_testmod_ops___zeroed testmod_zeroed = {
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.test_1 = (void *)test_1,
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.test_2 = (void *)test_2_v2,
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};
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