arch/powerpc/mm/kasan/8xx.c

   1 // SPDX-License-Identifier: GPL-2.0
   2
   3 #define DISABLE_BRANCH_PROFILING
   4
   5 #include <linux/kasan.h>
   6 #include <linux/memblock.h>
   7 #include <linux/hugetlb.h>
   8
   9 static int __init
  10 kasan_init_shadow_8M(unsigned long k_start, unsigned long k_end, void *block)
  11 {
  12         pmd_t *pmd = pmd_off_k(k_start);
  13         unsigned long k_cur, k_next;
  14
  15         for (k_cur = k_start; k_cur != k_end; k_cur = k_next, pmd += 2, block += SZ_8M) {
  16                 pte_basic_t *new;
  17
  18                 k_next = pgd_addr_end(k_cur, k_end);
  19                 k_next = pgd_addr_end(k_next, k_end);
  20                 if ((void *)pmd_page_vaddr(*pmd) != kasan_early_shadow_pte)
  21                         continue;
  22
  23                 new = memblock_alloc(sizeof(pte_basic_t), SZ_4K);
  24                 if (!new)
  25                         return -ENOMEM;
  26
  27                 *new = pte_val(pte_mkhuge(pfn_pte(PHYS_PFN(__pa(block)), PAGE_KERNEL)));
  28
  29                 hugepd_populate_kernel((hugepd_t *)pmd, (pte_t *)new, PAGE_SHIFT_8M);
  30                 hugepd_populate_kernel((hugepd_t *)pmd + 1, (pte_t *)new, PAGE_SHIFT_8M);
  31         }
  32         return 0;
  33 }
  34
  35 int __init kasan_init_region(void *start, size_t size)
  36 {
  37         unsigned long k_start = (unsigned long)kasan_mem_to_shadow(start);
  38         unsigned long k_end = (unsigned long)kasan_mem_to_shadow(start + size);
  39         unsigned long k_cur;
  40         int ret;
  41         void *block;
  42
  43         block = memblock_alloc(k_end - k_start, SZ_8M);
  44         if (!block)
  45                 return -ENOMEM;
  46
  47         if (IS_ALIGNED(k_start, SZ_8M)) {
  48                 kasan_init_shadow_8M(k_start, ALIGN_DOWN(k_end, SZ_8M), block);
  49                 k_cur = ALIGN_DOWN(k_end, SZ_8M);
  50                 if (k_cur == k_end)
  51                         goto finish;
  52         } else {
  53                 k_cur = k_start;
  54         }
  55
  56         ret = kasan_init_shadow_page_tables(k_start, k_end);
  57         if (ret)
  58                 return ret;
  59
  60         for (; k_cur < k_end; k_cur += PAGE_SIZE) {
  61                 pmd_t *pmd = pmd_off_k(k_cur);
  62                 void *va = block + k_cur - k_start;
  63                 pte_t pte = pfn_pte(PHYS_PFN(__pa(va)), PAGE_KERNEL);
  64
  65                 if (k_cur < ALIGN_DOWN(k_end, SZ_512K))
  66                         pte = pte_mkhuge(pte);
  67
  68                 __set_pte_at(&init_mm, k_cur, pte_offset_kernel(pmd, k_cur), pte, 0);
  69         }
  70 finish:
  71         flush_tlb_kernel_range(k_start, k_end);
  72         return 0;
  73 }