diff options
Diffstat (limited to 'kernel/sys_mm.cc')
| -rw-r--r-- | kernel/sys_mm.cc | 178 |
1 files changed, 0 insertions, 178 deletions
diff --git a/kernel/sys_mm.cc b/kernel/sys_mm.cc deleted file mode 100644 index bfa067c..0000000 --- a/kernel/sys_mm.cc +++ /dev/null @@ -1,178 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0-or-later */ -/* Copyright (C) 2026 Richard Qin */ - -/* - * Memory Management System Calls - * - * Implements: brk, mmap (anonymous only), munmap, mprotect. - * - * Reference: docs/specs/syscall.md §7.2 - */ - -#include <lume/types.h> -#include <lume/task.h> -#include <lume/vmm.h> -#include <lume/errno.h> -#include <lume/mman.h> -#include <lume/config.h> -#include <lume/klog.h> - - -/* Page alignment helpers */ -static inline uint64 page_align_up(uint64 x) -{ - return (x + kPageSize - 1) & ~(kPageSize - 1); -} - -static inline uint64 page_align_down(uint64 x) -{ - return x & ~(kPageSize - 1); -} - -/* ====================================================================== - * sys_brk - * ====================================================================== */ - -int64 sys_brk(uint64 new_brk, uint64, uint64, uint64, uint64, uint64) -{ - VmSpace* mm = current_task()->mm; - if (!mm) - return -ENOMEM; /* kernel threads have no user address space */ - - if (new_brk == 0) { - return static_cast<int64>(mm->brk_end); - } - - if (mm->brk_start == 0) { - uint64 init_brk = page_align_up(new_brk); - mm->brk_start = init_brk; - mm->brk_end = init_brk; - } - - if (new_brk < mm->brk_start) { - return -EINVAL; - } - - uint64 new_end = page_align_up(new_brk); - if (new_end > mm->brk_end) { - uint64 grow = new_end - mm->brk_end; - int ret = vmm_map_user(mm, mm->brk_end, grow, VM_READ | VM_WRITE); - if (ret < 0) { - return ret; - } - } else if (new_end < mm->brk_end) { - uint64 shrink = mm->brk_end - new_end; - int ret = vmm_unmap_user(mm, new_end, shrink); - if (ret < 0) { - return ret; - } - } - - mm->brk_end = new_end; - return static_cast<int64>(new_brk); -} - -/* ====================================================================== - * sys_mmap - * ====================================================================== */ - -int64 sys_mmap(uint64 addr, uint64 length, uint64 prot, - uint64 flags, uint64 fd, uint64 offset) -{ - printk("[mmap] addr=%llx len=%llx prot=%llx flags=%llx fd=%lld off=%llx\n", - addr, length, prot, flags, static_cast<int64>(fd), offset); - - if (length == 0) return -EINVAL; - length = page_align_up(length); - if (offset % kPageSize != 0) return -EINVAL; - - if ((flags & MAP_PRIVATE) && (flags & MAP_SHARED)) return -EINVAL; - if (!(flags & MAP_PRIVATE) && !(flags & MAP_SHARED)) return -EINVAL; - - VmSpace* mm = current_task()->mm; - if (!mm) return -ENOMEM; - - /* Phase 2: only anonymous private mappings */ - if (!(flags & MAP_ANONYMOUS)) { - printk("[mmap] REJECTED: file-backed mmap not implemented\n"); - return -ENOSYS; /* File-backed mmap is Phase 3 */ - } - if (flags & MAP_SHARED) - return -ENOSYS; /* Shared mappings are Phase 3 */ - - (void)fd; - - /* Convert POSIX prot → MI permission flags */ - uint64 vm_perm = 0; - if (prot & PROT_READ) vm_perm |= VM_READ; - if (prot & PROT_WRITE) vm_perm |= VM_WRITE; - if (prot & PROT_EXEC) vm_perm |= VM_EXEC; - vm_perm |= VM_USER; - - uint64 va = addr; - if (flags & MAP_FIXED) { - if (va % kPageSize != 0) return -EINVAL; - } else if (va != 0) { - va = page_align_down(va); - } - - if (va == 0) { - va = mm_find_free_va(mm, length, kPageSize); - if (!va) return -ENOMEM; - } - - if (flags & MAP_FIXED) { - int ret = vmm_unmap_user(mm, va, length); - if (ret < 0) return ret; - } - - int ret = vmm_map_user(mm, va, length, vm_perm); - if (ret < 0 && !(flags & MAP_FIXED) && addr != 0) { - uint64 fallback = mm_find_free_va(mm, length, kPageSize); - if (!fallback) return ret; - ret = vmm_map_user(mm, fallback, length, vm_perm); - if (ret < 0) return ret; - va = fallback; - } else if (ret < 0) { - return ret; - } - - return static_cast<int64>(va); -} - -/* ====================================================================== - * sys_munmap - * ====================================================================== */ - -int64 sys_munmap(uint64 addr, uint64 length, uint64, uint64, uint64, uint64) -{ - if (length == 0) return -EINVAL; - if (addr % kPageSize != 0) return -EINVAL; - length = page_align_up(length); - - VmSpace* mm = current_task()->mm; - if (!mm) return -EINVAL; - - return vmm_unmap_user(mm, addr, length); -} - -/* ====================================================================== - * sys_mprotect — Phase 2 stub - * ====================================================================== */ - -int64 sys_mprotect(uint64 addr, uint64 len, uint64 prot, - uint64, uint64, uint64) -{ - if (len == 0) return -EINVAL; - if (addr % kPageSize != 0) return -EINVAL; - - VmSpace* mm = current_task()->mm; - if (!mm) return -ENOMEM; - - uint64 vm_perm = 0; - if (prot & PROT_READ) vm_perm |= VM_READ; - if (prot & PROT_WRITE) vm_perm |= VM_WRITE; - if (prot & PROT_EXEC) vm_perm |= VM_EXEC; - - return vmm_protect_user(mm, addr, len, vm_perm); -} |