C++ pte_offset_kernel函数代码示例

static void stage2_flush_ptes(struct kvm *kvm, pmd_t *pmd,
			      phys_addr_t addr, phys_addr_t end)
{
	pte_t *pte;

	pte = pte_offset_kernel(pmd, addr);
	do {
		if (!pte_none(*pte)) {
			hva_t hva = gfn_to_hva(kvm, addr >> PAGE_SHIFT);
			kvm_flush_dcache_to_poc((void*)hva, PAGE_SIZE);
		}
	} while (pte++, addr += PAGE_SIZE, addr != end);
}

static void clear_pmd_entry(struct kvm *kvm, pmd_t *pmd, phys_addr_t addr)
{
	if (kvm_pmd_huge(*pmd)) {
		pmd_clear(pmd);
		kvm_tlb_flush_vmid_ipa(kvm, addr);
	} else {
		pte_t *pte_table = pte_offset_kernel(pmd, 0);
		pmd_clear(pmd);
		kvm_tlb_flush_vmid_ipa(kvm, addr);
		pte_free_kernel(NULL, pte_table);
	}
	put_page(virt_to_page(pmd));
}

static pte_t *__init kasan_pte_offset(pmd_t *pmdp, unsigned long addr, int node,
				      bool early)
{
	if (pmd_none(READ_ONCE(*pmdp))) {
		phys_addr_t pte_phys = early ?
				__pa_symbol(kasan_early_shadow_pte)
					: kasan_alloc_zeroed_page(node);
		__pmd_populate(pmdp, pte_phys, PMD_TYPE_TABLE);
	}

	return early ? pte_offset_kimg(pmdp, addr)
		     : pte_offset_kernel(pmdp, addr);
}

pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr)
{
	pgd_t *pgd;
	pud_t *pud;
	pmd_t *pmd;
	pte_t *pte = NULL;

	pgd = pgd_offset(mm, addr);
	pud = pud_offset(pgd, addr);
	pmd = pmd_offset(pud, addr);
	pte = pte_offset_kernel(pmd, addr);

	return pte;
}

int __init wip_init(void)
{
	unsigned long va = 0xb77e5000;
	int pid = 1072;
	//struct page p;
	unsigned long long pageFN;
	unsigned long long pa;

	pgd_t *pgd;
	pmd_t *pmd;
	pud_t *pud;
	pte_t *pte;
	
	struct mm_struct *mm;

	int found = 0;

	struct task_struct *task;
	for_each_process(task)
	{
		if(task->pid == pid)
			mm = task->mm;
	}
	pgd  = pgd_offset(mm,va);
	if(!pgd_none(*pgd) && !pgd_bad(*pgd))
	{
		pud = pud_offset(pgd,va);
		if(!pud_none(*pud) && !pud_bad(*pud))
		{
			pmd = pmd_offset(pud,va);
			if(!pmd_none(*pmd) && !pmd_bad(*pmd))
			{
				pte = pte_offset_kernel(pmd,va);
				if(!pte_none(*pte))
				{
					pageFN = pte_pfn(*pte);
					pa = ((pageFN<<12)|(va&0x00000FFF));
					found = 1;
					printk(KERN_ALERT "Physical Address: 0x%08llx\npfn: 0x%04llx\n", pa, pageFN);
				}
			}
		}
	}
	if(pgd_none(*pgd) || pud_none(*pud) || pmd_none(*pmd) || pte_none(*pte))
	{
		unsigned long long swapID = (pte_val(*pte) >> 32);
		found = 1;
		printk(KERN_ALERT "swap ID: 0x%08llx\n", swapID);
	}

pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr)
{
	pgd_t *pgd;
	pud_t *pud;
	pmd_t *pmd = NULL;
	pte_t *pte = NULL;

	pgd = pgd_offset(mm, addr);
	pr_debug("%s: addr:0x%lx pgd:%p\n", __func__, addr, pgd);
	if (!pgd_present(*pgd))
		return NULL;
	pud = pud_offset(pgd, addr);
	if (!pud_present(*pud))
		return NULL;

	if (pud_huge(*pud))
		return (pte_t *)pud;
	pmd = pmd_offset(pud, addr);
	if (!pmd_present(*pmd))
		return NULL;

	if (pte_cont(pmd_pte(*pmd))) {
		pmd = pmd_offset(
			pud, (addr & CONT_PMD_MASK));
		return (pte_t *)pmd;
	}
	if (pmd_huge(*pmd))
		return (pte_t *)pmd;
	pte = pte_offset_kernel(pmd, addr);
	if (pte_present(*pte) && pte_cont(*pte)) {
		pte = pte_offset_kernel(
			pmd, (addr & CONT_PTE_MASK));
		return pte;
	}
	return NULL;
}

/**
 * @brief   Translate user virtual address to physical address.
 * @param   va [in] user virtual address.
 * @return 	success: physical address, fail: 0
 * @see     CHUNK_MEM_FREE
 */
unsigned int gp_user_va_to_pa(void *va)
{
	pgd_t *pgd = NULL;
	pud_t *pud = NULL;
	pmd_t *pmd = NULL;
	pte_t *pte = NULL;
	struct mm_struct *mm = current->mm;
	unsigned int addr = (unsigned int)va;
	unsigned int pa = 0;

	down_read(&mm->mmap_sem);

	/* query page tables */
	if (!find_vma(mm, addr)) {
		DIAG_VERB("virt_addr %08X not available.\n", addr);
		goto out;
	}
	pgd = pgd_offset(mm, addr);
	if (pgd_none(*pgd)) {
		DIAG_VERB("Not mapped in pgd.\n");
		goto out;
	}
	pud = pud_offset(pgd, addr);
	if (pud_none(*pud)) {
		DIAG_VERB("Not mapped in pud.\n");
		goto out;
	}
	pmd = pmd_offset(pud, addr);
	if (pmd_none(*pmd)) {
		DIAG_VERB("Not mapped in pmd.\n");
		goto out;
	}
	pte = pte_offset_kernel(pmd, addr);
	if (pte_none(*pte)) {
		DIAG_VERB("Not mapped in pte.\n");
		goto out;
	}
	if (!pte_present(*pte)) {
		DIAG_VERB("pte not in RAM.\n");
		goto out;
	}

	pa = (pte_val(*pte) & PAGE_MASK) | (addr & ~PAGE_MASK);

out:
	up_read(&mm->mmap_sem);
	return pa;
}

static void create_hyp_pte_mappings(pmd_t *pmd, unsigned long start,
				    unsigned long end, unsigned long pfn,
				    pgprot_t prot)
{
	pte_t *pte;
	unsigned long addr;

	addr = start;
	do {
		pte = pte_offset_kernel(pmd, addr);
		kvm_set_pte(pte, pfn_pte(pfn, prot));
		get_page(virt_to_page(pte));
		kvm_flush_dcache_to_poc(pte, sizeof(*pte));
		pfn++;
	} while (addr += PAGE_SIZE, addr != end);
}

static void flush_kernel_vm_range(unsigned long start, unsigned long end, 
				  int update_seq)
{
	struct mm_struct *mm;
	pgd_t *pgd;
	pmd_t *pmd;
	pte_t *pte;
	unsigned long addr;
	int updated = 0, err;

	mm = &init_mm;
	for(addr = start; addr < end;){
		pgd = pgd_offset(mm, addr);
		pmd = pmd_offset(pgd, addr);
		if(pmd_present(*pmd)){
			pte = pte_offset_kernel(pmd, addr);
			if(!pte_present(*pte) || pte_newpage(*pte)){
				updated = 1;
				err = os_unmap_memory((void *) addr, 
						      PAGE_SIZE);
				if(err < 0)
					panic("munmap failed, errno = %d\n",
					      -err);
				if(pte_present(*pte))
					map_memory(addr, 
						   pte_val(*pte) & PAGE_MASK,
						   PAGE_SIZE, 1, 1, 1);
			}
			else if(pte_newprot(*pte)){
				updated = 1;
				protect_memory(addr, PAGE_SIZE, 1, 1, 1, 1);
			}
			addr += PAGE_SIZE;
		}
		else {
			if(pmd_newpage(*pmd)){
				updated = 1;
				err = os_unmap_memory((void *) addr, PMD_SIZE);
				if(err < 0)
					panic("munmap failed, errno = %d\n",
					      -err);
			}
			addr += PMD_SIZE;
		}
	}
	if(updated && update_seq) atomic_inc(&vmchange_seq);
}

static int stage2_set_pte(struct kvm *kvm, struct kvm_mmu_memory_cache *cache,
			  phys_addr_t addr, const pte_t *new_pte, bool iomap)
{
	pmd_t *pmd;
	pte_t *pte, old_pte;

	/* Create stage-2 page table mapping - Levels 0 and 1 */
	pmd = stage2_get_pmd(kvm, cache, addr);
	if (!pmd) {
		/*
		 * Ignore calls from kvm_set_spte_hva for unallocated
		 * address ranges.
		 */
		return 0;
	}

	/* Create stage-2 page mappings - Level 2 */
	if (pmd_none(*pmd)) {
		if (!cache)
			return 0; /* ignore calls from kvm_set_spte_hva */
		pte = mmu_memory_cache_alloc(cache);
		kvm_clean_pte(pte);
		pmd_populate_kernel(NULL, pmd, pte);
		get_page(virt_to_page(pmd));
	}

	pte = pte_offset_kernel(pmd, addr);

	if (iomap && pte_present(*pte))
		return -EFAULT;

	/* Create 2nd stage page table mapping - Level 3 */
	old_pte = *pte;
	if (pte_present(old_pte)) {
		/* Skip page table update if there is no change */
		if (pte_val(old_pte) == pte_val(*new_pte))
			return 0;

		kvm_set_pte(pte, __pte(0));
		kvm_tlb_flush_vmid_ipa(kvm, addr);
	} else {
		get_page(virt_to_page(pte));
	}

	kvm_set_pte(pte, *new_pte);
	return 0;
}

static void shmedia_mapioaddr(unsigned long pa, unsigned long va,
			      unsigned long flags)
{
	pgd_t *pgdp;
	pud_t *pudp;
	pmd_t *pmdp;
	pte_t *ptep, pte;
	pgprot_t prot;

	pr_debug("shmedia_mapiopage pa %08lx va %08lx\n",  pa, va);

	if (!flags)
		flags = 1; /* 1 = CB0-1 device */

	pgdp = pgd_offset_k(va);
	if (pgd_none(*pgdp) || !pgd_present(*pgdp)) {
		pudp = (pud_t *)sh64_get_page();
		set_pgd(pgdp, __pgd((unsigned long)pudp | _KERNPG_TABLE));
	}

	pudp = pud_offset(pgdp, va);
	if (pud_none(*pudp) || !pud_present(*pudp)) {
		pmdp = (pmd_t *)sh64_get_page();
		set_pud(pudp, __pud((unsigned long)pmdp | _KERNPG_TABLE));
	}

	pmdp = pmd_offset(pudp, va);
	if (pmd_none(*pmdp) || !pmd_present(*pmdp)) {
		ptep = (pte_t *)sh64_get_page();
		set_pmd(pmdp, __pmd((unsigned long)ptep + _PAGE_TABLE));
	}

	prot = __pgprot(_PAGE_PRESENT | _PAGE_READ     | _PAGE_WRITE  |
			_PAGE_DIRTY   | _PAGE_ACCESSED | _PAGE_SHARED | flags);

	pte = pfn_pte(pa >> PAGE_SHIFT, prot);
	ptep = pte_offset_kernel(pmdp, va);

	if (!pte_none(*ptep) &&
	    pte_val(*ptep) != pte_val(pte))
		pte_ERROR(*ptep);

	set_pte(ptep, pte);

	flush_tlb_kernel_range(va, PAGE_SIZE);
}

static int stage2_set_pte(struct kvm *kvm, struct kvm_mmu_memory_cache *cache,
			  phys_addr_t addr, const pte_t *new_pte, bool iomap)
{
	pgd_t *pgd;
	pud_t *pud;
	pmd_t *pmd;
	pte_t *pte, old_pte;

	/* Create 2nd stage page table mapping - Level 1 */
	pgd = kvm->arch.pgd + pgd_index(addr);
	pud = pud_offset(pgd, addr);
	if (pud_none(*pud)) {
		if (!cache)
			return 0; /* ignore calls from kvm_set_spte_hva */
		pmd = mmu_memory_cache_alloc(cache);
		pud_populate(NULL, pud, pmd);
		get_page(virt_to_page(pud));
	}

	pmd = pmd_offset(pud, addr);

	/* Create 2nd stage page table mapping - Level 2 */
	if (pmd_none(*pmd)) {
		if (!cache)
			return 0; /* ignore calls from kvm_set_spte_hva */
		pte = mmu_memory_cache_alloc(cache);
		kvm_clean_pte(pte);
		pmd_populate_kernel(NULL, pmd, pte);
		get_page(virt_to_page(pmd));
	}

	pte = pte_offset_kernel(pmd, addr);

	if (iomap && pte_present(*pte))
		return -EFAULT;

	/* Create 2nd stage page table mapping - Level 3 */
	old_pte = *pte;
	kvm_set_pte(pte, *new_pte);
	if (pte_present(old_pte))
		kvm_tlb_flush_vmid_ipa(kvm, addr);
	else
		get_page(virt_to_page(pte));

	return 0;
}

pte_t *lookup_address(unsigned long address) 
{ 
	pgd_t *pgd = pgd_offset_k(address);
	pud_t *pud;
	pmd_t *pmd;
	if (pgd_none(*pgd))
		return NULL;
	pud = pud_offset(pgd, address);
	if (pud_none(*pud))
		return NULL;
	pmd = pmd_offset(pud, address);
	if (pmd_none(*pmd))
		return NULL;
	if (pmd_large(*pmd))
		return (pte_t *)pmd;
        return pte_offset_kernel(pmd, address);
} 

static void __init permanent_kmaps_init(pgd_t *pgd_base)
{
	pgd_t *pgd;
	pud_t *pud;
	pmd_t *pmd;
	pte_t *pte;
	unsigned long vaddr;

	vaddr = PKMAP_BASE;
	page_table_range_init(vaddr, vaddr + PAGE_SIZE*LAST_PKMAP, pgd_base);

	pgd = swapper_pg_dir + pgd_index(vaddr);
	pud = pud_offset(pgd, vaddr);
	pmd = pmd_offset(pud, vaddr);
	pte = pte_offset_kernel(pmd, vaddr);
	pkmap_page_table = pte;
}

/*
 * The performance critical leaf functions are made noinline otherwise gcc
 * inlines everything into a single function which results in too much
 * register pressure.
 */
static noinline int gup_pte_range(pmd_t pmd, unsigned long addr,
		unsigned long end, int write, struct page **pages, int *nr)
{
	unsigned long mask, result;
	pte_t *ptep;

	if (tlb_type == hypervisor) {
		result = _PAGE_PRESENT_4V|_PAGE_P_4V;
		if (write)
			result |= _PAGE_WRITE_4V;
	} else {
		result = _PAGE_PRESENT_4U|_PAGE_P_4U;
		if (write)
			result |= _PAGE_WRITE_4U;
	}
	mask = result | _PAGE_SPECIAL;

	ptep = pte_offset_kernel(&pmd, addr);
	do {
		struct page *page, *head;
		pte_t pte = *ptep;

		if ((pte_val(pte) & mask) != result)
			return 0;
		VM_BUG_ON(!pfn_valid(pte_pfn(pte)));

		/* The hugepage case is simplified on sparc64 because
		 * we encode the sub-page pfn offsets into the
		 * hugepage PTEs.  We could optimize this in the future
		 * use page_cache_add_speculative() for the hugepage case.
		 */
		page = pte_page(pte);
		head = compound_head(page);
		if (!page_cache_get_speculative(head))
			return 0;
		if (unlikely(pte_val(pte) != pte_val(*ptep))) {
			put_page(head);
			return 0;
		}

		pages[*nr] = page;
		(*nr)++;
	} while (ptep++, addr += PAGE_SIZE, addr != end);

	return 1;
}