#include <lunaix/common.h>
#include <lunaix/syscall.h>
#include <lunaix/spike.h>
+#include <klibc/string.h>
LOG_MODULE("PROC")
for (size_t j = 0; j < PG_MAX_ENTRIES; j++)
{
x86_pte_t pte = ppt->entry[j];
- pmm_ref_page(pid, pte & ~0xfff);
+ pmm_ref_page(pid, PG_ENTRY_ADDR(pte));
pt->entry[j] = pte;
}
return ptd_pp;
}
+void __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++)
+ {
+ 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* dup_pagetable(pid_t pid) {
return __dup_pagetable(pid, PD_REFERENCED);
}
-__DEFINE_LXSYSCALL(void, fork) {
- dup_proc();
+__DEFINE_LXSYSCALL(pid_t, fork) {
+ return dup_proc();
}
__DEFINE_LXSYSCALL(pid_t, getpid) {
return __current->parent->pid;
}
-void dup_proc() {
- pid_t pid = alloc_pid();
+void init_proc(struct proc_info *pcb) {
+ memset(pcb, 0, sizeof(*pcb));
+
+ pcb->pid = alloc_pid();
+ pcb->created = clock_systime();
+ pcb->state = PROC_CREATED;
+}
- struct proc_info pcb = (struct proc_info) {
- .created = clock_systime(),
- .pid = pid,
- .mm = __current->mm,
- .intr_ctx = __current->intr_ctx,
- .parent = __current
- };
+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
// 根据 mm_region 进一步配置页表
- if (__current->mm.regions) {
- struct mm_region *pos, *n;
- llist_for_each(pos, n, &__current->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;
- }
+ if (!__current->mm.regions) {
+ goto not_copy;
+ }
+
+ struct mm_region *pos, *n;
+ llist_for_each(pos, n, &__current->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 = &((x86_page_table*)(PD_MOUNT_1 | ((i & 0xffc00) << 2)))->entry[i & 0x3ff];
- x86_pte_t *newproc = &((x86_page_table*)(PD_MOUNT_2 | ((i & 0xffc00) << 2)))->entry[i & 0x3ff];
-
- 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。
- *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 = 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(curproc);
+ 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。
+ *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;
}
}
}
+not_copy:
vmm_unmount_pd(PD_MOUNT_2);
// 正如同fork，返回两次。
pcb.intr_ctx.registers.eax = 0;
- __current->intr_ctx.registers.eax = pid;
push_process(&pcb);
+
+ return pcb.pid;
}
extern void __kernel_end;
// copy the kernel stack
for (size_t i = KSTACK_START >> 12; i <= KSTACK_TOP >> 12; i++)
{
- x86_pte_t *ppte = &((x86_page_table*)(PD_MOUNT_2 | ((i & 0xffc00) << 2)))->entry[i & 0x3ff];
- void* ppa = vmm_dup_page(pid, PG_ENTRY_ADDR(*ppte));
- *ppte = (*ppte & 0xfff) | (uintptr_t)ppa;
+ volatile x86_pte_t *ppte = &PTE_MOUNTED(PD_MOUNT_2, 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));
+ *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
git://scm.lunaixsky.com / lunaix-os.git / blobdiff