mm/kasan/8xx.c

0001 // SPDX-License-Identifier: GPL-2.0
0002
0003 #define DISABLE_BRANCH_PROFILING
0004
0005 #include <linux/kasan.h>
0006 #include <linux/memblock.h>
0007 #include <linux/hugetlb.h>
0008
0009 static int __init
0010 kasan_init_shadow_8M(unsigned long k_start, unsigned long k_end, void *block)
0011 {
0012     pmd_t *pmd = pmd_off_k(k_start);
0013     unsigned long k_cur, k_next;
0014
0015     for (k_cur = k_start; k_cur != k_end; k_cur = k_next, pmd += 2, block += SZ_8M) {
0016         pte_basic_t *new;
0017
0018         k_next = pgd_addr_end(k_cur, k_end);
0019         k_next = pgd_addr_end(k_next, k_end);
0020         if ((void *)pmd_page_vaddr(*pmd) != kasan_early_shadow_pte)
0021             continue;
0022
0023         new = memblock_alloc(sizeof(pte_basic_t), SZ_4K);
0024         if (!new)
0025             return -ENOMEM;
0026
0027         *new = pte_val(pte_mkhuge(pfn_pte(PHYS_PFN(__pa(block)), PAGE_KERNEL)));
0028
0029         hugepd_populate_kernel((hugepd_t *)pmd, (pte_t *)new, PAGE_SHIFT_8M);
0030         hugepd_populate_kernel((hugepd_t *)pmd + 1, (pte_t *)new, PAGE_SHIFT_8M);
0031     }
0032     return 0;
0033 }
0034
0035 int __init kasan_init_region(void *start, size_t size)
0036 {
0037     unsigned long k_start = (unsigned long)kasan_mem_to_shadow(start);
0038     unsigned long k_end = (unsigned long)kasan_mem_to_shadow(start + size);
0039     unsigned long k_cur;
0040     int ret;
0041     void *block;
0042
0043     block = memblock_alloc(k_end - k_start, SZ_8M);
0044     if (!block)
0045         return -ENOMEM;
0046
0047     if (IS_ALIGNED(k_start, SZ_8M)) {
0048         kasan_init_shadow_8M(k_start, ALIGN_DOWN(k_end, SZ_8M), block);
0049         k_cur = ALIGN_DOWN(k_end, SZ_8M);
0050         if (k_cur == k_end)
0051             goto finish;
0052     } else {
0053         k_cur = k_start;
0054     }
0055
0056     ret = kasan_init_shadow_page_tables(k_start, k_end);
0057     if (ret)
0058         return ret;
0059
0060     for (; k_cur < k_end; k_cur += PAGE_SIZE) {
0061         pmd_t *pmd = pmd_off_k(k_cur);
0062         void *va = block + k_cur - k_start;
0063         pte_t pte = pfn_pte(PHYS_PFN(__pa(va)), PAGE_KERNEL);
0064
0065         if (k_cur < ALIGN_DOWN(k_end, SZ_512K))
0066             pte = pte_mkhuge(pte);
0067
0068         __set_pte_at(&init_mm, k_cur, pte_offset_kernel(pmd, k_cur), pte, 0);
0069     }
0070 finish:
0071     flush_tlb_kernel_range(k_start, k_end);
0072     return 0;
0073 }