C++ pgd_bad函数代码示例

int m4u_v2p_new(unsigned int va)
{
   unsigned int pmdOffset = (va & (PMD_SIZE - 1));
   unsigned int pageOffset = (va & (PAGE_SIZE - 1));
   pgd_t *pgd;
   pmd_t *pmd;
   pte_t *pte;
   unsigned int pa;
   printk("Enter m4u_user_v2p()! 0x%x\n", va);
   
   pgd = pgd_offset(current->mm, va); /* what is tsk->mm */
   printk("m4u_user_v2p(), pgd 0x%x\n", pgd);    
   printk("pgd_none=%d, pgd_bad=%d\n", pgd_none(*pgd), pgd_bad(*pgd));
   
   if(pgd_none(*pgd)||pgd_bad(*pgd))
   {
      printk("Error: m4u_user_v2p(), virtual addr 0x%x, pgd invalid! \n", va);
      return 0;
   }
   
   pmd = pmd_offset(pgd, va);
   printk("m4u_user_v2p(), pmd 0x%x\n", pmd);
   printk("pmd_none=%d, pmd_bad=%d, pmd_val=0x%x\n", pmd_none(*pmd), pmd_bad(*pmd), pmd_val(*pmd));
   
   
   /* If this is a page table entry, keep on walking to the next level */ 
   if (( (unsigned int)pmd_val(*pmd) & PMD_TYPE_MASK) == PMD_TYPE_TABLE)
   {
      if(pmd_none(*pmd)||pmd_bad(*pmd))
      {
         printk("Error: m4u_user_v2p(), virtual addr 0x%x, pmd invalid! \n", va);
         return 0;
      }
      
      pte = pte_offset_map(pmd, va);
      printk("m4u_user_v2p(), pte 0x%x\n", pte);
      if(pte_present(*pte)) 
      { 
         pa=(pte_val(*pte) & (PAGE_MASK)) | pageOffset; 
         printk("PA = 0x%8x\n", pa);
         return pa; 
      }
   }
   else /* Only 1 level page table */
   {
      if(pmd_none(*pmd))
      {
         printk("Error: m4u_user_v2p(), virtual addr 0x%x, pmd invalid! \n", va);
         return 0;
      }
      pa=(pte_val(*pmd) & (PMD_MASK)) | pmdOffset; 
      printk("PA = 0x%8x\n", pa);
      return pa;

   }
   
   return 0;   
}

static inline int copy_pmd_range(pgd_t *dst_pgd, pgd_t *src_pgd, unsigned long address, unsigned long size, int cow)
{
	pmd_t * src_pmd, * dst_pmd;
	unsigned long end;
	int error = 0;

	if (pgd_none(*src_pgd))
		return 0;
	if (pgd_bad(*src_pgd)) {
		printk("copy_pmd_range: bad pgd (%08lx)\n", pgd_val(*src_pgd));
		pgd_clear(src_pgd);
		return 0;
	}
	src_pmd = pmd_offset(src_pgd, address);
	if (pgd_none(*dst_pgd)) {
		if (!pmd_alloc(dst_pgd, 0))
			return -ENOMEM;
	}
	dst_pmd = pmd_offset(dst_pgd, address);
	address &= ~PGDIR_MASK;
	end = address + size;
	if (end > PGDIR_SIZE)
		end = PGDIR_SIZE;
	do {
		error = copy_pte_range(dst_pmd++, src_pmd++, address, end - address, cow);
		if (error)
			break;
		address = (address + PMD_SIZE) & PMD_MASK; 
	} while (address < end);
	return error;
}

/*
 * This function zeroes out partial mmap'ed pages at truncation time..
 */
static void partial_clear(struct vm_area_struct *vma, unsigned long address)
{
	pgd_t *page_dir;
	pmd_t *page_middle;
	pte_t *page_table, pte;

	page_dir = pgd_offset(vma->vm_mm, address);
	if (pgd_none(*page_dir))
		return;
	if (pgd_bad(*page_dir)) {
		printk("bad page table directory entry %p:[%lx]\n", page_dir, pgd_val(*page_dir));
		pgd_clear(page_dir);
		return;
	}
	page_middle = pmd_offset(page_dir, address);
	if (pmd_none(*page_middle))
		return;
	if (pmd_bad(*page_middle)) {
		printk("bad page table directory entry %p:[%lx]\n", page_dir, pgd_val(*page_dir));
		pmd_clear(page_middle);
		return;
	}
	page_table = pte_offset(page_middle, address);
	pte = *page_table;
	if (!pte_present(pte))
		return;
	flush_cache_page(vma, address);
	address &= ~PAGE_MASK;
	address += pte_page(pte);
	if (address >= high_memory)
		return;
	memset((void *) address, 0, PAGE_SIZE - (address & ~PAGE_MASK));
	flush_page_to_ram(pte_page(pte));
}

static void shmedia_unmapioaddr(unsigned long vaddr)
{
	pgd_t *pgdp;
	pud_t *pudp;
	pmd_t *pmdp;
	pte_t *ptep;

	pgdp = pgd_offset_k(vaddr);
	if (pgd_none(*pgdp) || pgd_bad(*pgdp))
		return;

	pudp = pud_offset(pgdp, vaddr);
	if (pud_none(*pudp) || pud_bad(*pudp))
		return;

	pmdp = pmd_offset(pudp, vaddr);
	if (pmd_none(*pmdp) || pmd_bad(*pmdp))
		return;

	ptep = pte_offset_kernel(pmdp, vaddr);

	if (pte_none(*ptep) || !pte_present(*ptep))
		return;

	clear_page((void *)ptep);
	pte_clear(&init_mm, vaddr, ptep);
}

static inline void
remove_mapping_pmd_range (pgd_t *pgd, unsigned long address, unsigned long size)
{
	pmd_t *pmd;
	unsigned long end;

	if (pgd_none (*pgd))
		return;

	if (pgd_bad (*pgd)){
		printk ("remove_graphics_pmd_range: bad pgd (%08lx)\n", pgd_val (*pgd));
		pgd_clear (pgd);
		return;
	}
	pmd = pmd_offset (pgd, address);
	address &= ~PGDIR_MASK;
	end = address + size;
	if (end > PGDIR_SIZE)
		end = PGDIR_SIZE;
	do {
		remove_mapping_pte_range (pmd, address, end - address);
		address = (address + PMD_SIZE) & PMD_MASK;
		pmd++;
	} while (address < end);
		
}

static inline void unswap_pgd(struct vm_area_struct * vma, pgd_t *dir,
			      unsigned long address, unsigned long size,
			      unsigned long entry, unsigned long page
			      /* , int isswap */)
{
	pmd_t * pmd;
	unsigned long offset, end;

	if (pgd_none(*dir))
		return;
	if (pgd_bad(*dir)) {
		printk("unswap_pgd: bad pgd (%08lx)\n", pgd_val(*dir));
		pgd_clear(dir);
		return;
	}
	pmd = pmd_offset(dir, address);
	offset = address & PGDIR_MASK;
	address &= ~PGDIR_MASK;
	end = address + size;
	if (end > PGDIR_SIZE)
		end = PGDIR_SIZE;
	do {
		unswap_pmd(vma, pmd, address, end - address, offset, entry,
			   page /* , isswap */);
		address = (address + PMD_SIZE) & PMD_MASK;
		pmd++;
	} while (address < end);
}

static inline int unuse_pgd(struct vm_area_struct * vma, pgd_t *dir,
	unsigned long address, unsigned long size,
	unsigned int type, unsigned long page)
{
	pmd_t * pmd;
	unsigned long offset, end;

	if (pgd_none(*dir))
		return 0;
	if (pgd_bad(*dir)) {
		printk("unuse_pgd: bad pgd (%08lx)\n", pgd_val(*dir));
		pgd_clear(dir);
		return 0;
	}
	pmd = pmd_offset(dir, address);
	offset = address & PGDIR_MASK;
	address &= ~PGDIR_MASK;
	end = address + size;
	if (end > PGDIR_SIZE)
		end = PGDIR_SIZE;
	do {
		if (unuse_pmd(vma, pmd, address, end - address, offset, type, page))
			return 1;
		address = (address + PMD_SIZE) & PMD_MASK;
		pmd++;
	} while (address < end);
	return 0;
}

static struct page* my_follow_page(struct vm_area_struct *vma, unsigned long addr) {
	pud_t *pud = NULL;
	pmd_t *pmd = NULL;
	pgd_t *pgd = NULL;
	pte_t *pte = NULL;
	spinlock_t *ptl = NULL;
	struct page* page = NULL;
	struct mm_struct *mm = current->mm;
	pgd = pgd_offset(current->mm, addr);
	if (pgd_none(*pgd) || unlikely(pgd_bad(*pgd))) {
		goto out;
	}
	pud = pud_offset(pgd, addr);
	if (pud_none(*pud) || unlikely(pud_bad(*pud))) {
		goto out;
	}
	printk("aaaa\n");
	pmd = pmd_offset(pud, addr);
	if (pmd_none(*pmd) || unlikely(pmd_bad(*pmd))) {
		goto out;
	}
	pte = pte_offset_map_lock(current->mm, pmd, addr, &ptl);
	printk("bbbb\n");
	if (!pte) goto out;
	printk("cccc\n");
	if (!pte_present(*pte)) goto unlock;
	page = pfn_to_page(pte_pfn(*pte));
	if (!page) goto unlock;
	get_page(page);
unlock:
	pte_unmap_unlock(pte, ptl);
out:
	return page;
}

static inline int swap_out_pgd(struct mm_struct * mm, struct vm_area_struct * vma, pgd_t *dir, unsigned long address, unsigned long end, int gfp_mask)
{
	pmd_t * pmd;
	unsigned long pgd_end;

	if (pgd_none(*dir))
		return 0;
	if (pgd_bad(*dir)) {
		pgd_ERROR(*dir);
		pgd_clear(dir);
		return 0;
	}

	pmd = pmd_offset(dir, address);

	pgd_end = (address + PGDIR_SIZE) & PGDIR_MASK;	
	if (pgd_end && (end > pgd_end))
		end = pgd_end;
	
	do {
		int result = swap_out_pmd(mm, vma, pmd, address, end, gfp_mask);
		if (result)
			return result;
		if (!mm->swap_cnt)
			return 0;
		address = (address + PMD_SIZE) & PMD_MASK;
		pmd++;
	} while (address && (address < end));
	return 0;
}

/*
 * This routine gets a long from any process space by following the page
 * tables. NOTE! You should check that the long isn't on a page boundary,
 * and that it is in the task area before calling this: this routine does
 * no checking.
 */
static unsigned long get_long(struct vm_area_struct * vma, unsigned long addr)
{
	pgd_t * pgdir;
	pte_t * pgtable;
	unsigned long page;

repeat:
	pgdir = PAGE_DIR_OFFSET(vma->vm_mm, addr);
	if (pgd_none(*pgdir)) {
		do_no_page(vma, addr, 0);
		goto repeat;
	}
	if (pgd_bad(*pgdir)) {
		printk("ptrace: bad page directory %08lx\n", pgd_val(*pgdir));
		pgd_clear(pgdir);
		return 0;
	}
	pgtable = (pte_t *) (PAGE_PTR(addr) + pgd_page(*pgdir));
	if (!pte_present(*pgtable)) {
		do_no_page(vma, addr, 0);
		goto repeat;
	}
	page = pte_page(*pgtable);
/* this is a hack for non-kernel-mapped video buffers and similar */
	if (page >= high_memory)
		return 0;
	page += addr & ~PAGE_MASK;
	return *(unsigned long *) page;
}

static inline int filemap_sync_pmd_range(pgd_t * pgd,
	unsigned long address, unsigned long end, 
	struct vm_area_struct *vma, unsigned int flags)
{
	pmd_t * pmd;
	int error;

	if (pgd_none(*pgd))
		return 0;
	if (pgd_bad(*pgd)) {
		pgd_ERROR(*pgd);
		pgd_clear(pgd);
		return 0;
	}
	pmd = pmd_offset(pgd, address);
	if ((address & PGDIR_MASK) != (end & PGDIR_MASK))
		end = (address & PGDIR_MASK) + PGDIR_SIZE;
	error = 0;
	do {
		error |= filemap_sync_pte_range(pmd, address, end, vma, flags);
		address = (address + PMD_SIZE) & PMD_MASK;
		pmd++;
	} while (address && (address < end));
	return error;
}

/*
 * Dump out the page tables associated with 'addr' in mm 'mm'.
 */
void show_pte(struct mm_struct *mm, unsigned long addr)
{
    pgd_t *pgd;

    if (!mm)
        mm = &init_mm;

    pr_alert("pgd = %p\n", mm->pgd);
    pgd = pgd_offset(mm, addr);
    pr_alert("[%08lx] *pgd=%016llx", addr, pgd_val(*pgd));

    do {
        pud_t *pud;
        pmd_t *pmd;
        pte_t *pte;

        if (pgd_none(*pgd) || pgd_bad(*pgd))
            break;

        pud = pud_offset(pgd, addr);
        if (pud_none(*pud) || pud_bad(*pud))
            break;

        pmd = pmd_offset(pud, addr);
        printk(", *pmd=%016llx", pmd_val(*pmd));
        if (pmd_none(*pmd) || pmd_bad(*pmd))
            break;

        pte = pte_offset_map(pmd, addr);
        printk(", *pte=%016llx", pte_val(*pte));
        pte_unmap(pte);
    } while(0);

    printk("\n");
}

static int
pin_page_for_write(const void __user *_addr, pte_t **ptep, spinlock_t **ptlp)
{
	unsigned long addr = (unsigned long)_addr;
	pgd_t *pgd;
	pmd_t *pmd;
	pte_t *pte;
	pud_t *pud;
	spinlock_t *ptl;

	pgd = pgd_offset(current->mm, addr);
	if (unlikely(pgd_none(*pgd) || pgd_bad(*pgd)))
		return 0;

	pud = pud_offset(pgd, addr);
	if (unlikely(pud_none(*pud) || pud_bad(*pud)))
		return 0;

	pmd = pmd_offset(pud, addr);
	if (unlikely(pmd_none(*pmd) || pmd_bad(*pmd)))
		return 0;

	pte = pte_offset_map_lock(current->mm, pmd, addr, &ptl);
	if (unlikely(!pte_present(*pte) || !pte_young(*pte) ||
	    !pte_write(*pte) || !pte_dirty(*pte))) {
		pte_unmap_unlock(pte, ptl);
		return 0;
	}

	*ptep = pte;
	*ptlp = ptl;

	return 1;
}

u32
imm_get_physical(void *v, u32 immid)
{
	pmd_t *pmd;
	pte_t *pte;
	pgd_t *pgd;
	u32 val = 0, virtual = (u32)v;
	struct mm_struct* mm;

	if (IMMID_USER(immid))
		mm = current->mm;
	else
		mm = &init_mm;

	pgd = pgd_offset(mm, virtual);
	if (!pgd_none(*pgd) && !pgd_bad(*pgd)) {
		/* 1st level entry pointer */
		pmd = pmd_offset(pgd, virtual);
		if (!pmd_none(*pmd) && !pmd_bad(*pmd)) {
			/* 2nd level entry pointer */
			pte = pte_offset_kernel(pmd, virtual);
			if (pte) {
				val = (*(u32 *)((u32)pte-2048))&PAGE_MASK;
				val += virtual%PAGE_SIZE;
			}
		} else if (!pmd_none(*pmd)) {

static inline int zap_pmd_range(struct mm_struct *mm, pgd_t * dir, unsigned long address, unsigned long size)
{
	pmd_t * pmd;
	unsigned long end;
	int freed;

	if (pgd_none(*dir))
		return 0;
	if (pgd_bad(*dir)) {
		pgd_ERROR(*dir);
		pgd_clear(dir);
		return 0;
	}
	pmd = pmd_offset(dir, address);
	address &= ~PGDIR_MASK;
	end = address + size;
	if (end > PGDIR_SIZE)
		end = PGDIR_SIZE;
	freed = 0;
	do {
		freed += zap_pte_range(mm, pmd, address, end - address);
		address = (address + PMD_SIZE) & PMD_MASK; 
		pmd++;
	} while (address < end);
	return freed;
}