lunaix-os/kernel/mm/cow.c

   1 #include <lunaix/mm/vmm.h>
   2
   3 void* vmm_dup_page(void* va) {
   4     void* new_ppg = pmm_alloc_page(KERNEL_PID, 0);
   5     vmm_fmap_page(KERNEL_PID, PG_MOUNT_3, new_ppg, PG_PREM_RW);
   6
   7     asm volatile (
   8         "movl %1, %%edi\n"
   9         "rep movsl\n"
  10         :: "c"(1024), "r"(PG_MOUNT_3), "S"((uintptr_t)va)
  11         : "memory", "%edi");
  12
  13     vmm_unset_mapping(PG_MOUNT_3);
  14
  15     return new_ppg;
  16 }