TermiNexus
7d5380148b
内核 MMAP(addr,length,prot,flags,fd,offset)：fd=-1 + MAP_ANONYMOUS 走匿名映射（分配物理页、清零后映射到本进程新 VA，对齐 Linux"匿名必为零"语义）；fd 是带 mmap_info 的 devfs 设备（当前仅 /dev/fb0）则把 [phys+offset, phys+offset+len) 按页映射进调用者地址空间（PTE_USER|WRITE）。addr/MAP_FIXED 暂未实现，一律由内核挑 VA 并返回真实起始地址。新增 PROT_*/MAP_*/MMAP_FD_ANON 常量。 参数次序与 Linux mmap 完全一致（rdi/rsi/rdx/r10/r8/r9），syscall_entry 的搬运顺序本就是这个约定，SDK 侧 vpsdk/syscall.vp 加 mmap() 助手走 _syscall6。stdlib.malloc 随之改为匿名映射调用（fd=-1、MAP_PRIVATE|MAP_ANONYMOUS、PROT_READ|PROT_WRITE），行为与原 MMAP(size) 一致且多一层清零。
62 lines
2.1 KiB
Plaintext
62 lines
2.1 KiB
Plaintext
import vpsdk.syscall as _sc
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import string
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define HEAP_BLOCK_MAGIC = 0x48454150
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class _heap_hdr:
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magic: uint32
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size: uint32
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_heap_inited: int = 0
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def _heap_init():
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global _heap_inited
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_heap_inited = 1
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export def malloc(size: sizet) -> rawptr:
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global _heap_inited
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if size == 0: return None
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if _heap_inited == 0: _heap_init()
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hdr_size: sizet = _heap_hdr.__sizeof__()
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total: sizet = hdr_size + size
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# mmap 已按 Linux 六参形态对齐：匿名映射 = fd -1 + MAP_ANONYMOUS + PROT_READ|WRITE
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ptr: uint64 = _sc.mmap(0, uint64(total), uint64(_sc.PROT_READ | _sc.PROT_WRITE),
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uint64(_sc.MAP_PRIVATE | _sc.MAP_ANONYMOUS), _sc.MMAP_FD_ANON, 0)
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if ptr == 0: return None
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# 块头必须落在**映射区内部**（映射起点 ptr 处），不能写 ptr - hdr_size：
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# 那 8 字节在映射之外 —— 第一次 malloc 时 mmap 返回的正是用户堆起点 0x20000000，
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# 写 0x1ffffff8 就是映射区外 ⇒ #PF(err=0x7 用户态写)，四个 app 启动即崩的现场。
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hdr: _heap_hdr* = _heap_hdr*(uint64(ptr))
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hdr.magic = HEAP_BLOCK_MAGIC
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hdr.size = uint32(size)
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return rawptr(ptr + hdr_size)
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export def free(ptr: rawptr):
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if ptr is None: return
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hdr_size: sizet = _heap_hdr.__sizeof__()
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hdr: _heap_hdr* = _heap_hdr*(uint64(ptr) - hdr_size)
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if hdr.magic != HEAP_BLOCK_MAGIC: return
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export def calloc(nmemb: sizet, size: sizet) -> rawptr:
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total: sizet = nmemb * size
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p: rawptr = malloc(total)
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if p: string.memset(p, 0, total)
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return p
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export def realloc(ptr: rawptr, size: sizet) -> rawptr:
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if ptr is None: return malloc(size)
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if size == 0:
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free(ptr)
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return None
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hdr_size: sizet = _heap_hdr.__sizeof__()
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hdr: _heap_hdr* = _heap_hdr*(uint64(ptr) - hdr_size)
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if hdr.magic != HEAP_BLOCK_MAGIC: return None
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old_size: sizet = hdr.size
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new_ptr: rawptr = malloc(size)
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if new_ptr is None: return None
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copy_size: sizet = old_size if old_size < size else size
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string.memcpy(new_ptr, ptr, copy_size)
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free(ptr)
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return new_ptr
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