f760d05379
Add barrier() and barrier_var() macros into bpf_helpers.h to be used by end users. While a bit advanced and specialized instruments, they are sometimes indispensable. Instead of requiring each user to figure out exact asm volatile incantations for themselves, provide them from bpf_helpers.h. Also remove conflicting definitions from selftests. Some tests rely on barrier_var() definition being nothing, those will still work as libbpf does the #ifndef/#endif guarding for barrier() and barrier_var(), allowing users to redefine them, if necessary. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20220509004148.1801791-8-andrii@kernel.org
32 lines
449 B
C
32 lines
449 B
C
// SPDX-License-Identifier: GPL-2.0
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// Copyright (c) 2019 Facebook
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#include <linux/bpf.h>
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#include <bpf/bpf_helpers.h>
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char _license[] SEC("license") = "GPL";
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SEC("socket")
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int while_true(volatile struct __sk_buff* skb)
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{
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int i = 0;
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while (1) {
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if (skb->len)
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i += 3;
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else
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i += 7;
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if (i == 9)
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break;
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barrier();
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if (i == 10)
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break;
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barrier();
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if (i == 13)
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break;
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barrier();
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if (i == 14)
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break;
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}
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return i;
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}
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