fix(starry-perf): replace magic numbers with named constants#1402
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CN-TangLin wants to merge 4 commits into
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fix(starry-perf): replace magic numbers with named constants#1402CN-TangLin wants to merge 4 commits into
CN-TangLin wants to merge 4 commits into
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Replace raw config values 0/1 in kprobe/uprobe dispatch with named constants PROBE_CONFIG_ENTRY / PROBE_CONFIG_RETURN, matching the Linux PERF_TYPE_PROBE ABI. Also refactor the kprobe config match from a nested if/else chain into flat const-pattern match arms.
为 BpfPerfEventWrapper 实现 try_read_record 方法，使 perf event fd 支持 read(2) 系统调用读取 ringbuf 中的 eBPF 输出记录。 主要变更： - bpf.rs: 添加 mmap_kvirt 字段保存 ringbuf 内核虚拟地址，实现 try_read_record 从 perf_event_mmap_page 读取 data_head/data_tail， 处理环缓冲区 wrapping，读取 perf_event_header 确定记录尺寸， 推进 data_tail；添加 wrapping_add/copy_ring 辅助函数 - mod.rs: 实现 FileLike::read，通过 downcast 获取 BpfPerfEventWrapper 并调用 try_read_record，使用 PAGE_SIZE_4K 作为栈缓冲区尺寸常量
将 PerfEvent::read 从轮询式非阻塞读重构为基于 block_on(poll_io(...)) 的阻塞读模式，匹配 Linux read(perf_fd) 语义。当 ringbuf 无数据时 返回 WouldBlock 让 poll_io 等待，数据到达后由已有的 BpfPerfEventWrapper poll 基础设施（poll_ready/poll_notify/IrqNotify） 唤醒任务继续读取。 重构要点： - 使用 block_on(poll_io(...)) 替代简单轮询，复用已有的 Pollable 实现 - read 闭包在返回 WouldBlock 前释放 SpinNoPreempt 锁 - 通过 PerfEvent::poll → BpfPerfEventWrapper::poll 获取可读性状态 - 通过 PerfEvent::register → BpfPerfEventWrapper::register 注册 waker
消除 perf 模块中的两处硬编码： - BPF_JIT_MEM_PAGES = 4：x86_64 JIT 可执行内存页数 - KRETPROBE_MAX_ACTIVE = 10：kretprobe 最大并发实例数 使用命名常量替代字面量，提高代码可读性和可维护性。
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…pf/tracepoint Replace magic numbers with named constants and improve security in perf, ebpf, and tracepoint subsystems: - perf/kprobe: add PROBE_CONFIG_ENTRY/RETURN constants, refactor config match from if/else chain into const-pattern arms - perf/bpf: add BPF_JIT_MEM_PAGES constant, replace magic 4 with it - perf/bpf: remove vm.register_allowed_memory(0..u64::MAX) to restrict BPF direct memory access, preventing buggy/hostile programs from reading arbitrary kernel memory - perf/kprobe: add KRETPROBE_MAX_ACTIVE constant (10, per Linux max(10, 2*NR_CPUS) for single-CPU), replace magic 10 in builder - tracepoint/mod: add MAX_ACTIVE_TRACEPOINTS (16) and MAX_SLOTS_PER_TRACEPOINT (64) constants - ebpf/mod: add MAX_EXEC_MEM_PAGES (256) constant, replace magic 256 in JIT executable memory allocation Changes combined from PRs rcore-os#1399, rcore-os#1402, rcore-os#1404, rcore-os#1405.
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问题
perf 模块中存在两处硬编码的数字字面量，降低了代码可读性和可维护性：
BPFJitMemory::new(4)—— JIT 可执行内存页数KretprobeBuilder::new(10)—— kretprobe 最大并发实例数变更
定义为命名常量并替换：
BPF_JIT_MEM_PAGES: usize = 4—— x86_64 BPF JIT 可执行内存页数，附带注释说明KRETPROBE_MAX_ACTIVE: u32 = 10—— 匹配 Linuxmax(10, 2*NR_CPUS)默认值逻辑
遵循"严禁硬编码"原则，使用命名常量替代字面量，提高代码可读性和可维护性。