mm/kasan/book3s_32.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 <mm/mmu_decl.h>
0008
0009 int __init kasan_init_region(void *start, size_t size)
0010 {
0011     unsigned long k_start = (unsigned long)kasan_mem_to_shadow(start);
0012     unsigned long k_end = (unsigned long)kasan_mem_to_shadow(start + size);
0013     unsigned long k_nobat = k_start;
0014     unsigned long k_cur;
0015     phys_addr_t phys;
0016     int ret;
0017
0018     while (k_nobat < k_end) {
0019         unsigned int k_size = bat_block_size(k_nobat, k_end);
0020         int idx = find_free_bat();
0021
0022         if (idx == -1)
0023             break;
0024         if (k_size < SZ_128K)
0025             break;
0026         phys = memblock_phys_alloc_range(k_size, k_size, 0,
0027                          MEMBLOCK_ALLOC_ANYWHERE);
0028         if (!phys)
0029             break;
0030
0031         setbat(idx, k_nobat, phys, k_size, PAGE_KERNEL);
0032         k_nobat += k_size;
0033     }
0034     if (k_nobat != k_start)
0035         update_bats();
0036
0037     if (k_nobat < k_end) {
0038         phys = memblock_phys_alloc_range(k_end - k_nobat, PAGE_SIZE, 0,
0039                          MEMBLOCK_ALLOC_ANYWHERE);
0040         if (!phys)
0041             return -ENOMEM;
0042     }
0043
0044     ret = kasan_init_shadow_page_tables(k_start, k_end);
0045     if (ret)
0046         return ret;
0047
0048     kasan_update_early_region(k_start, k_nobat, __pte(0));
0049
0050     for (k_cur = k_nobat; k_cur < k_end; k_cur += PAGE_SIZE) {
0051         pmd_t *pmd = pmd_off_k(k_cur);
0052         pte_t pte = pfn_pte(PHYS_PFN(phys + k_cur - k_nobat), PAGE_KERNEL);
0053
0054         __set_pte_at(&init_mm, k_cur, pte_offset_kernel(pmd, k_cur), pte, 0);
0055     }
0056     flush_tlb_kernel_range(k_start, k_end);
0057     memset(kasan_mem_to_shadow(start), 0, k_end - k_start);
0058
0059     return 0;
0060 }