#include <klibc/string.h>
#include <lunaix/clock.h>
#include <lunaix/common.h>
+#include <lunaix/mm/pmm.h>
#include <lunaix/mm/region.h>
#include <lunaix/mm/vmm.h>
#include <lunaix/process.h>
__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];
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);
{
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;
}
void*
-dup_pagetable(pid_t pid)
+vmm_dup_vmspace(pid_t pid)
{
return __dup_pagetable(pid, PD_REFERENCED);
}
}
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;
+ }
+ }
}
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;
+
+ 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;
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
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
git://scm.lunaixsky.com / lunaix-os.git / blobdiff