| Wang Kefeng | 7596968 | 2021-12-03 10:26:33 +0100 | [diff] [blame] | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
| 2 | |
| 3 | #ifndef __ASM_ARM_KFENCE_H |
| 4 | #define __ASM_ARM_KFENCE_H |
| 5 | |
| 6 | #include <linux/kfence.h> |
| 7 | |
| 8 | #include <asm/pgalloc.h> |
| 9 | #include <asm/set_memory.h> |
| 10 | |
| 11 | static inline int split_pmd_page(pmd_t *pmd, unsigned long addr) |
| 12 | { |
| 13 | int i; |
| 14 | unsigned long pfn = PFN_DOWN(__pa(addr)); |
| 15 | pte_t *pte = pte_alloc_one_kernel(&init_mm); |
| 16 | |
| 17 | if (!pte) |
| 18 | return -ENOMEM; |
| 19 | |
| 20 | for (i = 0; i < PTRS_PER_PTE; i++) |
| 21 | set_pte_ext(pte + i, pfn_pte(pfn + i, PAGE_KERNEL), 0); |
| 22 | pmd_populate_kernel(&init_mm, pmd, pte); |
| 23 | |
| 24 | flush_tlb_kernel_range(addr, addr + PMD_SIZE); |
| 25 | return 0; |
| 26 | } |
| 27 | |
| 28 | static inline bool arch_kfence_init_pool(void) |
| 29 | { |
| 30 | unsigned long addr; |
| 31 | pmd_t *pmd; |
| 32 | |
| 33 | for (addr = (unsigned long)__kfence_pool; is_kfence_address((void *)addr); |
| 34 | addr += PAGE_SIZE) { |
| 35 | pmd = pmd_off_k(addr); |
| 36 | |
| 37 | if (pmd_leaf(*pmd)) { |
| 38 | if (split_pmd_page(pmd, addr & PMD_MASK)) |
| 39 | return false; |
| 40 | } |
| 41 | } |
| 42 | |
| 43 | return true; |
| 44 | } |
| 45 | |
| 46 | static inline bool kfence_protect_page(unsigned long addr, bool protect) |
| 47 | { |
| 48 | set_memory_valid(addr, 1, !protect); |
| 49 | |
| 50 | return true; |
| 51 | } |
| 52 | |
| 53 | #endif /* __ASM_ARM_KFENCE_H */ |