/* 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);
}
/* 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);
}