mirror of
https://github.com/xdp-project/bpf-examples.git
synced 2024-05-06 15:54:53 +00:00
9ea235637e
This is taken from the Cilium project: https://github.com/cilium/cilium/blob/master/bpf/include/bpf/compiler.h The use-case was adding READ_ONCE and WRITE_ONCE, but via re-using the Cilium version we get a lot more useful compiler annotations. Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
125 lines
2.6 KiB
C
125 lines
2.6 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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/* Copyright (C) 2016-2020 Authors of Cilium */
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#ifndef __BPF_COMPILER_H_
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#define __BPF_COMPILER_H_
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#ifndef __non_bpf_context
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# include "stddef.h"
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#endif
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#ifndef __section
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# define __section(X) __attribute__((section(X), used))
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#endif
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#ifndef __maybe_unused
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# define __maybe_unused __attribute__((__unused__))
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#endif
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#ifndef offsetof
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# define offsetof(T, M) __builtin_offsetof(T, M)
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#endif
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#ifndef field_sizeof
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# define field_sizeof(T, M) sizeof((((T *)NULL)->M))
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#endif
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#ifndef __packed
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# define __packed __attribute__((packed))
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#endif
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#ifndef __nobuiltin
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# if __clang_major__ >= 10
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# define __nobuiltin(X) __attribute__((no_builtin(X)))
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# else
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# define __nobuiltin(X)
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# endif
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#endif
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#ifndef likely
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# define likely(X) __builtin_expect(!!(X), 1)
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#endif
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#ifndef unlikely
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# define unlikely(X) __builtin_expect(!!(X), 0)
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#endif
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#ifndef always_succeeds /* Mainly for documentation purpose. */
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# define always_succeeds(X) likely(X)
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#endif
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#undef __always_inline /* stddef.h defines its own */
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#define __always_inline inline __attribute__((always_inline))
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#ifndef __stringify
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# define __stringify(X) #X
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#endif
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#ifndef __fetch
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# define __fetch(X) (__u32)(__u64)(&(X))
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#endif
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#ifndef __aligned
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# define __aligned(X) __attribute__((aligned(X)))
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#endif
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#ifndef build_bug_on
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# define build_bug_on(E) ((void)sizeof(char[1 - 2*!!(E)]))
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#endif
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#ifndef __throw_build_bug
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# define __throw_build_bug() __builtin_trap()
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#endif
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#ifndef __printf
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# define __printf(X, Y) __attribute__((__format__(printf, X, Y)))
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#endif
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#ifndef barrier
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# define barrier() asm volatile("": : :"memory")
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#endif
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#ifndef barrier_data
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# define barrier_data(ptr) asm volatile("": :"r"(ptr) :"memory")
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#endif
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static __always_inline void bpf_barrier(void)
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{
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/* Workaround to avoid verifier complaint:
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* "dereference of modified ctx ptr R5 off=48+0, ctx+const is allowed,
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* ctx+const+const is not"
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*/
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barrier();
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}
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#ifndef ARRAY_SIZE
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# define ARRAY_SIZE(A) (sizeof(A) / sizeof((A)[0]))
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#endif
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#ifndef __READ_ONCE
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# define __READ_ONCE(X) (*(volatile typeof(X) *)&X)
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#endif
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#ifndef __WRITE_ONCE
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# define __WRITE_ONCE(X, V) (*(volatile typeof(X) *)&X) = (V)
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#endif
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/* {READ,WRITE}_ONCE() with verifier workaround via bpf_barrier(). */
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#ifndef READ_ONCE
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# define READ_ONCE(X) \
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({ typeof(X) __val = __READ_ONCE(X); \
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bpf_barrier(); \
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__val; })
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#endif
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#ifndef WRITE_ONCE
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# define WRITE_ONCE(X, V) \
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({ typeof(X) __val = (V); \
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__WRITE_ONCE(X, __val); \
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bpf_barrier(); \
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__val; })
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#endif
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#endif /* __BPF_COMPILER_H_ */
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