tools/testing/selftests/bpf/bpf_legacy.h

File Facts

System

Linux kernel

Corpus path

tools/testing/selftests/bpf/bpf_legacy.h

Extension

.h

Size

895 bytes

Lines

24

Domain

Support Tooling And Documentation

Bucket

tools

Inferred role

Support Tooling And Documentation: implementation source

Status

source implementation candidate

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

• Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

Dependency Surface

• No C-style include directives detected by the generator.

Detected Declarations

• No top-level syscall, struct, function, initcall, or export declaration detected by the generator.

Annotated Snippet

#ifndef __BPF_LEGACY__
#define __BPF_LEGACY__

#if __GNUC__ && !__clang__
/* Functions to emit BPF_LD_ABS and BPF_LD_IND instructions.  We
 * provide the "standard" names as synonyms of the corresponding GCC
 * builtins. Note how the SKB argument is ignored.
 */
#define load_byte(skb, off) __builtin_bpf_load_byte(off)
#define load_half(skb, off) __builtin_bpf_load_half(off)
#define load_word(skb, off) __builtin_bpf_load_word(off)
#else
/* llvm builtin functions that eBPF C program may use to
 * emit BPF_LD_ABS and BPF_LD_IND instructions
 */
unsigned long long load_byte(void *skb, unsigned long long off) asm("llvm.bpf.load.byte");
unsigned long long load_half(void *skb, unsigned long long off) asm("llvm.bpf.load.half");
unsigned long long load_word(void *skb, unsigned long long off) asm("llvm.bpf.load.word");
#endif

#endif

Annotation

• Atlas domain: Support Tooling And Documentation / tools.
• Implementation status: source implementation candidate.

Implementation Notes

• This generated page is the file-by-file coverage layer; curated subsystem chapters should link here when they synthesize a multi-file control flow.
• Core OS pages should be promoted from atlas-only to deep-reviewed when they explain data structures, invariants, locking, lifecycle, and C implementation snippets.
• Driver-family pages are intentionally pattern-oriented unless they are part of the selected PCIe/NVMe representative device path.