Example #1
0
/* Is address valid for reading? */
static int valid_address(struct KBacktraceIterator *kbt, VirtualAddress address)
{
	HV_PTE *l1_pgtable = kbt->pgtable;
	HV_PTE *l2_pgtable;
	unsigned long pfn;
	HV_PTE pte;
	struct page *page;

	if (l1_pgtable == NULL)
		return 0;	/* can't read user space in other tasks */

	pte = l1_pgtable[HV_L1_INDEX(address)];
	if (!hv_pte_get_present(pte))
		return 0;
	pfn = hv_pte_get_pfn(pte);
	if (pte_huge(pte)) {
		if (!pfn_valid(pfn)) {
			pr_err("huge page has bad pfn %#lx\n", pfn);
			return 0;
		}
		return hv_pte_get_present(pte) && hv_pte_get_readable(pte);
	}

	page = pfn_to_page(pfn);
	if (PageHighMem(page)) {
		pr_err("L2 page table not in LOWMEM (%#llx)\n",
		       HV_PFN_TO_CPA(pfn));
		return 0;
	}
	l2_pgtable = (HV_PTE *)pfn_to_kaddr(pfn);
	pte = l2_pgtable[HV_L2_INDEX(address)];
	return hv_pte_get_present(pte) && hv_pte_get_readable(pte);
}
Example #2
0
/* Is address valid for reading? */
static int valid_address(struct KBacktraceIterator *kbt, unsigned long address)
{
	HV_PTE *l1_pgtable = kbt->pgtable;
	HV_PTE *l2_pgtable;
	unsigned long pfn;
	HV_PTE pte;
	struct page *page;

	if (l1_pgtable == NULL)
		return 0;	/* can't read user space in other tasks */

#ifdef CONFIG_64BIT
	/* Find the real l1_pgtable by looking in the l0_pgtable. */
	pte = l1_pgtable[HV_L0_INDEX(address)];
	if (!hv_pte_get_present(pte))
		return 0;
	pfn = hv_pte_get_pfn(pte);
	if (pte_huge(pte)) {
		if (!pfn_valid(pfn)) {
			pr_err("L0 huge page has bad pfn %#lx\n", pfn);
			return 0;
		}
		return hv_pte_get_present(pte) && hv_pte_get_readable(pte);
	}
	page = pfn_to_page(pfn);
	BUG_ON(PageHighMem(page));  /* No HIGHMEM on 64-bit. */
	l1_pgtable = (HV_PTE *)pfn_to_kaddr(pfn);
#endif
	pte = l1_pgtable[HV_L1_INDEX(address)];
	if (!hv_pte_get_present(pte))
		return 0;
	pfn = hv_pte_get_pfn(pte);
	if (pte_huge(pte)) {
		if (!pfn_valid(pfn)) {
			pr_err("huge page has bad pfn %#lx\n", pfn);
			return 0;
		}
		return hv_pte_get_present(pte) && hv_pte_get_readable(pte);
	}

	page = pfn_to_page(pfn);
	if (PageHighMem(page)) {
		pr_err("L2 page table not in LOWMEM (%#llx)\n",
		       HV_PFN_TO_CPA(pfn));
		return 0;
	}
	l2_pgtable = (HV_PTE *)pfn_to_kaddr(pfn);
	pte = l2_pgtable[HV_L2_INDEX(address)];
	return hv_pte_get_present(pte) && hv_pte_get_readable(pte);
}