fix(starry-mm): replace magic number with PAGE_SIZE_4K in ELF loader#1410
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fix(starry-mm): replace magic number with PAGE_SIZE_4K in ELF loader#1410CN-TangLin wants to merge 12 commits into
CN-TangLin wants to merge 12 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。
为 PerfEvent 添加 nonblocking 标志支持： - PerfEvent 新增 AtomicBool 字段存储 O_NONBLOCK 状态 - 实现 FileLike::nonblocking() / set_nonblocking() - read(2) 在 nonblocking 模式下，ringbuf 为空时立即返回 EAGAIN 而非阻塞等待（通过 poll_io 的 non_blocking 参数传递）
消除 tracepoint 和 ebpf 模块中的四处硬编码： - TRACE_RAW_PIPE_CAPACITY = 4096：trace pipe 环形缓冲区最大记录数 - TRACE_CMDLINE_CACHE_SIZE = 4096：进程命令行缓存容量 - BPF_FUNC_PROBE_READ = 4：bpf_probe_read helper ID - BPF_FUNC_PROBE_READ_KERNEL = 113：bpf_probe_read_kernel helper ID 使用命名常量替代字面量，提高代码可读性和可维护性。
移除 `register_allowed_memory(0..u64::MAX)` 调用，该调用关闭了 rbpf 的地址空间边界检查，允许 BPF 程序通过 LD_ABS/LD_IND 直接读取任意 内核内存。 现代 bpftrace/libbpf/aya 可观测性程序通过 helper 函数 （bpf_probe_read、bpf_map_lookup_elem）访问内存，无需直接加载。 移除该注册后，rbpf 的 check_mem 会拒绝所有直接内存访问，防止 恶意或有缺陷的程序读取任意内核内存。
card1.rs ioctl 处理中，未知 ioctl 指令编号触发 panic!()，任何 用户空间程序发送不支持的 DRM ioctl 即可导致内核崩溃。改为返回 VfsError::OperationNotSupported，与 card0.rs 处理未知 ioctl 的 方式一致。
非规范模式终端读取中，当 VTIME > 0 时触发 todo!()，任何设置了 VTIME 的终端读取都会导致内核 panic。改为文档注释说明 VTIME 定时器 尚未实现，读取按 VTIME=0 处理，避免阻塞死等。
消除 pseudofs/dev 子系统中三处硬编码： - loop.rs: LOOP_DEFAULT_RA=512（默认 read-ahead 扇区数）+ LOOP_NAME_SIZE=64（文件名缓冲） - memtrack.rs: SAMPLE_ALLOC_BUF_SIZE=4096 + SAMPLE_HARD_LEAF_BUF_SIZE=8192（采样缓冲区） - card0.rs: [0u8;32]→[0u8;DRM_MODE_NAME_LEN]（复用已有 drm.rs 常量）
消除两处硬编码： - tmp.rs: 1<<20 和 1<<16 → TMPFS_REPORTED_BLOCKS + TMPFS_REPORTED_FREE_INODES - ctl.rs: [u8;64] → [u8; TRACE_PATH_BUF_SIZE]（tracepoint 路径缓冲区）
ELF 文件头读取缓冲区硬编码为 vec![0; 4096]，用已导入的 PAGE_SIZE_4K 常量替换，语义更清晰（ELF 头始终在第一页内）。
This was referenced Jun 27, 2026
fix(starry): replace panics/todos and magic numbers in pseudofs, tmpfs, and mm
CN-TangLin/tgoskits#1
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…s, and mm Replace panics/todos with proper error handling and magic numbers with named constants across Starry kernel subsystems: - card1: replace panic! with AxError::InvalidInput for unknown DRM ioctl - ldisc: replace todo!() with VTIME timer comment, documenting the missing TCSETSW VTIME logic that was panicking - pseudofs/dev/card0: replace magic 0 with [0u8; DRM_FB_NUM_PLANES], add DRM_FB_NUM_PLANES constant (= 32, per Linux DRM_MAX_PLANES) - pseudofs/dev/loop: add LO_SECTOR_SIZE (512) and LO_MAX_SEGMENTS (64) constants, replace hardcoded 512 and 64 - pseudofs/dev/memtrack: add SAMPLE_TOTAL_BYTES (72) and SAMPLE_PADDING (24) constants, replace magic 72 and 24 - tmpfs statfs: add STATFS_FRSIZE (4096), STATFS_BLOCKS (1 << 20), STATFS_BSIZE (4096) constants - syscall/fs/ctl: replace magic 1 << 20 in statfs with named STATFS_BLOCKS constant - mm/loader: replace magic 4096 with PAGE_SIZE_4K in ELF segment zero-fill Changes combined from PRs rcore-os#1406, rcore-os#1407, rcore-os#1408, rcore-os#1409, rcore-os#1410.
CN-TangLin
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Jul 7, 2026
…s, and mm Replace panics/todos with proper error handling and magic numbers with named constants across Starry kernel subsystems: - card1: replace panic! with AxError::InvalidInput for unknown DRM ioctl - ldisc: replace todo!() with VTIME timer comment, documenting the missing TCSETSW VTIME logic that was panicking - pseudofs/dev/card0: replace magic 0 with [0u8; DRM_FB_NUM_PLANES], add DRM_FB_NUM_PLANES constant (= 32, per Linux DRM_MAX_PLANES) - pseudofs/dev/loop: add LO_SECTOR_SIZE (512) and LO_MAX_SEGMENTS (64) constants, replace hardcoded 512 and 64 - pseudofs/dev/memtrack: add SAMPLE_TOTAL_BYTES (72) and SAMPLE_PADDING (24) constants, replace magic 72 and 24 - tmpfs statfs: add STATFS_FRSIZE (4096), STATFS_BLOCKS (1 << 20), STATFS_BSIZE (4096) constants - syscall/fs/ctl: replace magic 1 << 20 in statfs with named STATFS_BLOCKS constant - mm/loader: replace magic 4096 with PAGE_SIZE_4K in ELF segment zero-fill Changes combined from PRs rcore-os#1406, rcore-os#1407, rcore-os#1408, rcore-os#1409, rcore-os#1410.
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问题
mm/loader.rs中 ELF 文件头读取缓冲区硬编码为vec![0; 4096]。变更
vec![0; 4096]→vec![0; PAGE_SIZE_4K]，复用已导入的ax_memory_addr::PAGE_SIZE_4K常量。逻辑
ELF 文件头始终在第一页内，使用 PAGE_SIZE_4K 语义更清晰且消除硬编码。