X-Git-Url: https://scm.lunaixsky.com/lunaix-os.git/blobdiff_plain/e66387b252f36c894d79769cbfb178bc950600d4..bc34fd00d2e81fbc890bb2060ed6693454a230bf:/lunaix-os/kernel/process.c diff --git a/lunaix-os/kernel/process.c b/lunaix-os/kernel/process.c index 020dfb4..086a5e3 100644 --- a/lunaix-os/kernel/process.c +++ b/lunaix-os/kernel/process.c @@ -1,7 +1,9 @@ #include #include #include +#include #include +#include #include #include #include @@ -15,19 +17,30 @@ void* __dup_pagetable(pid_t pid, uintptr_t mount_point) { void* ptd_pp = pmm_alloc_page(pid, PP_FGPERSIST); - x86_page_table* ptd = vmm_fmap_page(pid, PG_MOUNT_1, ptd_pp, PG_PREM_RW); + vmm_set_mapping(PD_REFERENCED, PG_MOUNT_1, ptd_pp, PG_PREM_RW, VMAP_NULL); + + x86_page_table* ptd = PG_MOUNT_1; x86_page_table* pptd = (x86_page_table*)(mount_point | (0x3FF << 12)); + size_t kspace_l1inx = L1_INDEX(KERNEL_MM_BASE); + for (size_t i = 0; i < PG_MAX_ENTRIES - 1; i++) { + x86_pte_t ptde = pptd->entry[i]; - if (!ptde || !(ptde & PG_PRESENT)) { + // 空或者是未在内存中的L1页表项直接照搬过去。 + // 内核地址空间直接共享过去。 + if (!ptde || i >= kspace_l1inx || !(ptde & PG_PRESENT)) { ptd->entry[i] = ptde; continue; } - x86_page_table* ppt = (x86_page_table*)(mount_point | (i << 12)); + // 复制L2页表 void* pt_pp = pmm_alloc_page(pid, PP_FGPERSIST); - x86_page_table* pt = vmm_fmap_page(pid, PG_MOUNT_2, pt_pp, PG_PREM_RW); + vmm_set_mapping( + PD_REFERENCED, PG_MOUNT_2, pt_pp, PG_PREM_RW, VMAP_NULL); + + x86_page_table* ppt = (x86_page_table*)(mount_point | (i << 12)); + x86_page_table* pt = PG_MOUNT_2; for (size_t j = 0; j < PG_MAX_ENTRIES; j++) { x86_pte_t pte = ppt->entry[j]; @@ -35,7 +48,7 @@ __dup_pagetable(pid_t pid, uintptr_t mount_point) pt->entry[j] = pte; } - ptd->entry[i] = (uintptr_t)pt_pp | PG_PREM_RW; + ptd->entry[i] = (uintptr_t)pt_pp | PG_ENTRY_FLAGS(ptde); } ptd->entry[PG_MAX_ENTRIES - 1] = NEW_L1_ENTRY(T_SELF_REF_PERM, ptd_pp); @@ -48,7 +61,8 @@ __del_pagetable(pid_t pid, uintptr_t mount_point) { x86_page_table* pptd = (x86_page_table*)(mount_point | (0x3FF << 12)); - for (size_t i = 0; i < PG_MAX_ENTRIES - 1; i++) { + // only remove user address space + for (size_t i = 0; i < L1_INDEX(KERNEL_MM_BASE); i++) { x86_pte_t ptde = pptd->entry[i]; if (!ptde || !(ptde & PG_PRESENT)) { continue; @@ -71,7 +85,7 @@ __del_pagetable(pid_t pid, uintptr_t mount_point) } void* -dup_pagetable(pid_t pid) +vmm_dup_vmspace(pid_t pid) { return __dup_pagetable(pid, PD_REFERENCED); } @@ -101,7 +115,7 @@ __DEFINE_LXSYSCALL2(int, setpgid, pid_t, pid, pid_t, pgid) struct proc_info* proc = pid ? get_process(pid) : __current; if (!proc) { - __current->k_status = LXINVL; + __current->k_status = EINVAL; return -1; } @@ -110,7 +124,7 @@ __DEFINE_LXSYSCALL2(int, setpgid, pid_t, pid, pid_t, pgid) struct proc_info* gruppenfuhrer = get_process(pgid); if (!gruppenfuhrer || proc->pgid == proc->pid) { - __current->k_status = LXINVL; + __current->k_status = EINVAL; return -1; } @@ -122,75 +136,94 @@ __DEFINE_LXSYSCALL2(int, setpgid, pid_t, pid, pid_t, pgid) } void -init_proc(struct proc_info* pcb) +init_proc_user_space(struct proc_info* pcb) { - memset(pcb, 0, sizeof(*pcb)); + vmm_mount_pd(PD_MOUNT_1, pcb->page_table); + + /*--- 分配用户栈 ---*/ - pcb->pid = alloc_pid(); - pcb->created = clock_systime(); - pcb->state = PROC_CREATED; - pcb->pgid = pcb->pid; + // 注册用户栈区域 + region_add( + &pcb->mm.regions, USTACK_END, USTACK_TOP, REGION_RW | REGION_RSHARED); + + // 预留地址空间,具体物理页将由Page Fault Handler按需分配。 + for (uintptr_t i = PG_ALIGN(USTACK_END); i < USTACK_TOP; i += PG_SIZE) { + vmm_set_mapping(PD_MOUNT_1, i, 0, PG_ALLOW_USER | PG_WRITE, VMAP_NULL); + } + + // todo: other uspace initialization stuff + + vmm_unmount_pd(PD_MOUNT_1); +} + +void +__mark_region(uintptr_t start_vpn, uintptr_t end_vpn, int attr) +{ + for (size_t i = start_vpn; i <= end_vpn; i++) { + x86_pte_t* curproc = &PTE_MOUNTED(PD_REFERENCED, i); + x86_pte_t* newproc = &PTE_MOUNTED(PD_MOUNT_1, i); + cpu_invplg(newproc); + + if ((attr & REGION_MODE_MASK) == REGION_RSHARED) { + // 如果读共享,则将两者的都标注为只读,那么任何写入都将会应用COW策略。 + cpu_invplg(curproc); + cpu_invplg(i << 12); + *curproc = *curproc & ~PG_WRITE; + *newproc = *newproc & ~PG_WRITE; + } else { + // 如果是私有页,则将该页从新进程中移除。 + *newproc = 0; + } + } +} + +void +__copy_fdtable(struct proc_info* pcb) +{ + for (size_t i = 0; i < VFS_MAX_FD; i++) { + struct v_fd* fd = __current->fdtable->fds[i]; + if (!fd) + continue; + vfs_dup_fd(fd, &pcb->fdtable->fds[i]); + } } pid_t dup_proc() { - struct proc_info pcb; - init_proc(&pcb); - pcb.mm = __current->mm; - pcb.intr_ctx = __current->intr_ctx; - pcb.parent = __current; - -#ifdef USE_KERNEL_PG - setup_proc_mem(&pcb, PD_MOUNT_1); //挂载点#1是当前进程的页表 -#else - setup_proc_mem(&pcb, PD_REFERENCED); -#endif + struct proc_info* pcb = alloc_process(); + pcb->mm.u_heap = __current->mm.u_heap; + pcb->intr_ctx = __current->intr_ctx; + pcb->parent = __current; + + __copy_fdtable(pcb); + region_copy(&__current->mm.regions, &pcb->mm.regions); + + setup_proc_mem(pcb, PD_REFERENCED); // 根据 mm_region 进一步配置页表 - if (!__current->mm.regions) { - goto not_copy; - } - llist_init_head(&pcb.mm.regions); struct mm_region *pos, *n; - llist_for_each(pos, n, &__current->mm.regions->head, head) + llist_for_each(pos, n, &pcb->mm.regions.head, head) { - region_add(&pcb, pos->start, pos->end, pos->attr); - // 如果写共享,则不作处理。 if ((pos->attr & REGION_WSHARED)) { continue; } - uintptr_t start_vpn = PG_ALIGN(pos->start) >> 12; - uintptr_t end_vpn = PG_ALIGN(pos->end) >> 12; - for (size_t i = start_vpn; i < end_vpn; i++) { - x86_pte_t* curproc = &PTE_MOUNTED(PD_MOUNT_1, i); - x86_pte_t* newproc = &PTE_MOUNTED(PD_MOUNT_2, i); - cpu_invplg(newproc); - - if (pos->attr == REGION_RSHARED) { - // 如果读共享,则将两者的都标注为只读,那么任何写入都将会应用COW策略。 - cpu_invplg(curproc); - *curproc = *curproc & ~PG_WRITE; - *newproc = *newproc & ~PG_WRITE; - } else { - // 如果是私有页,则将该页从新进程中移除。 - *newproc = 0; - } - } + uintptr_t start_vpn = pos->start >> 12; + uintptr_t end_vpn = pos->end >> 12; + __mark_region(start_vpn, end_vpn, pos->attr); } -not_copy: - vmm_unmount_pd(PD_MOUNT_2); + vmm_unmount_pd(PD_MOUNT_1); // 正如同fork,返回两次。 - pcb.intr_ctx.registers.eax = 0; + pcb->intr_ctx.registers.eax = 0; - push_process(&pcb); + commit_process(pcb); - return pcb.pid; + return pcb->pid; } extern void __kernel_end; @@ -202,11 +235,11 @@ setup_proc_mem(struct proc_info* proc, uintptr_t usedMnt) pid_t pid = proc->pid; void* pt_copy = __dup_pagetable(pid, usedMnt); - vmm_mount_pd(PD_MOUNT_2, pt_copy); // 将新进程的页表挂载到挂载点#2 + vmm_mount_pd(PD_MOUNT_1, pt_copy); // 将新进程的页表挂载到挂载点#2 // copy the kernel stack for (size_t i = KSTACK_START >> 12; i <= KSTACK_TOP >> 12; i++) { - volatile x86_pte_t* ppte = &PTE_MOUNTED(PD_MOUNT_2, i); + volatile x86_pte_t* ppte = &PTE_MOUNTED(PD_MOUNT_1, i); /* This is a fucking nightmare, the TLB caching keep the rewrite to PTE @@ -220,18 +253,13 @@ setup_proc_mem(struct proc_info* proc, uintptr_t usedMnt) x86_pte_t p = *ppte; void* ppa = vmm_dup_page(pid, PG_ENTRY_ADDR(p)); + pmm_free_page(pid, PG_ENTRY_ADDR(p)); *ppte = (p & 0xfff) | (uintptr_t)ppa; } // 我们不需要分配内核的区域,因为所有的内核代码和数据段只能通过系统调用来访问,任何非法的访问 // 都会导致eip落在区域外面,从而segmentation fault. - // 定义用户栈区域,但是不分配实际的物理页。我们会在Page fault - // handler里面实现动态分配物理页的逻辑。(虚拟内存的好处!) - // FIXME: 这里应该放到spawn_proc里面。 - // region_add(proc, USTACK_END, USTACK_SIZE, REGION_PRIVATE | REGION_RW); - // 至于其他的区域我们暂时没有办法知道,因为那需要知道用户程序的信息。我们留到之后在处理。 - proc->page_table = pt_copy; } \ No newline at end of file