-#include <lunaix/process.h>
-#include <lunaix/mm/vmm.h>
+#include <klibc/string.h>
#include <lunaix/clock.h>
-#include <lunaix/syslog.h>
#include <lunaix/common.h>
+#include <lunaix/mm/pmm.h>
+#include <lunaix/mm/region.h>
+#include <lunaix/mm/valloc.h>
+#include <lunaix/mm/vmm.h>
+#include <lunaix/process.h>
+#include <lunaix/spike.h>
+#include <lunaix/status.h>
+#include <lunaix/syscall.h>
+#include <lunaix/syslog.h>
LOG_MODULE("PROC")
-void dup_proc() {
- pid_t pid = alloc_pid();
-
+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);
- x86_page_table* pptd = (x86_page_table*) L1_BASE_VADDR;
+ 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++) {
- 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*) L2_VADDR(i);
+
+ // 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);
-
- for (size_t j = 0; j < PG_MAX_ENTRIES; j++)
- {
- uintptr_t va = ((i << 10) | j) << 12;
- x86_pte_t ppte = ppt->entry[j];
- if (!ppte || !(ppte & PG_PRESENT)) {
- pt->entry[j] = ppte;
- continue;
- }
+ vmm_set_mapping(
+ PD_REFERENCED, PG_MOUNT_2, pt_pp, PG_PREM_RW, VMAP_NULL);
- // FIXME: 根据 mm_region 将读共享的页（如堆）标为只读，而私有的页（如栈），则复制；而写共享的页则无需更改flags
- if (va >= KSTACK_START) {
- void* ppa = vmm_dup_page(va);
- ppte = ppte & 0xfff | (uintptr_t)ppa;
- }
- pt->entry[j] = ppte;
- // ppte = ppte & ~PG_WRITE;
- // pt->entry[j] = ppte;
- // ppt->entry[j] = ppte;
+ 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];
+ pmm_ref_page(pid, PG_ENTRY_ADDR(pte));
+ 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);
- struct proc_info pcb = (struct proc_info) {
- .created = clock_systime(),
- .pid = pid,
- .mm = __current->mm,
- .page_table = ptd_pp,
- .intr_ctx = __current->intr_ctx,
- .parent_created = __current->created
- };
-
- // 正如同fork一样，返回两次。
- pcb.intr_ctx.registers.eax = 0;
- __current->intr_ctx.registers.eax = pid;
-
- push_process(&pcb);
-
+ return ptd_pp;
+}
+
+void
+__del_pagetable(pid_t pid, uintptr_t mount_point)
+{
+ x86_page_table* pptd = (x86_page_table*)(mount_point | (0x3FF << 12));
+
+ // 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;
+ }
+
+ x86_page_table* ppt = (x86_page_table*)(mount_point | (i << 12));
+
+ for (size_t j = 0; j < PG_MAX_ENTRIES; j++) {
+ x86_pte_t pte = ppt->entry[j];
+ // free the 4KB data page
+ if ((pte & PG_PRESENT)) {
+ pmm_free_page(pid, PG_ENTRY_ADDR(pte));
+ }
+ }
+ // free the L2 page table
+ pmm_free_page(pid, PG_ENTRY_ADDR(ptde));
+ }
+ // free the L1 directory
+ pmm_free_page(pid, PG_ENTRY_ADDR(pptd->entry[PG_MAX_ENTRIES - 1]));
+}
+
+void*
+vmm_dup_vmspace(pid_t pid)
+{
+ return __dup_pagetable(pid, PD_REFERENCED);
+}
+
+__DEFINE_LXSYSCALL(pid_t, fork)
+{
+ return dup_proc();
+}
+
+__DEFINE_LXSYSCALL(pid_t, getpid)
+{
+ return __current->pid;
+}
+
+__DEFINE_LXSYSCALL(pid_t, getppid)
+{
+ return __current->parent->pid;
+}
+
+__DEFINE_LXSYSCALL(pid_t, getpgid)
+{
+ return __current->pgid;
+}
+
+__DEFINE_LXSYSCALL2(int, setpgid, pid_t, pid, pid_t, pgid)
+{
+ struct proc_info* proc = pid ? get_process(pid) : __current;
+
+ if (!proc) {
+ __current->k_status = EINVAL;
+ return -1;
+ }
+
+ pgid = pgid ? pgid : proc->pid;
+
+ struct proc_info* gruppenfuhrer = get_process(pgid);
+
+ if (!gruppenfuhrer || proc->pgid == proc->pid) {
+ __current->k_status = EINVAL;
+ return -1;
+ }
+
+ llist_delete(&proc->grp_member);
+ llist_append(&gruppenfuhrer->grp_member, &proc->grp_member);
+
+ proc->pgid = pgid;
+ return 0;
+}
+
+void
+init_proc_user_space(struct proc_info* pcb)
+{
+ vmm_mount_pd(PD_MOUNT_1, pcb->page_table);
+
+ /*--- 分配用户栈 ---*/
+
+ // 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 = 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
+
+ struct mm_region *pos, *n;
+ llist_for_each(pos, n, &pcb->mm.regions.head, head)
+ {
+ // 如果写共享，则不作处理。
+ if ((pos->attr & REGION_WSHARED)) {
+ continue;
+ }
+
+ uintptr_t start_vpn = pos->start >> 12;
+ uintptr_t end_vpn = pos->end >> 12;
+ __mark_region(start_vpn, end_vpn, pos->attr);
+ }
+
+ vmm_unmount_pd(PD_MOUNT_1);
+
+ // 正如同fork，返回两次。
+ pcb->intr_ctx.registers.eax = 0;
+
+ commit_process(pcb);
+
+ return pcb->pid;
+}
+
+extern void __kernel_end;
+
+void
+setup_proc_mem(struct proc_info* proc, uintptr_t usedMnt)
+{
+ // copy the entire kernel page table
+ pid_t pid = proc->pid;
+ void* pt_copy = __dup_pagetable(pid, usedMnt);
+
+ 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_1, i);
+
+ /*
+ This is a fucking nightmare, the TLB caching keep the rewrite to PTE
+ from updating. Even the Nightmare Moon the Evil is far less nasty
+ than this. It took me hours of debugging to figure this out.
+
+ In the name of Celestia our glorious goddess, I will fucking HATE
+ the TLB for the rest of my LIFE!
+ */
+ cpu_invplg(ppte);
+
+ 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.
+
+ // 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
git://scm.lunaixsky.com / lunaix-os.git / blobdiff