| /* SPDX-License-Identifier: GPL-2.0 */ |
| |
| #ifndef __ASM_ARM_KFENCE_H |
| #define __ASM_ARM_KFENCE_H |
| |
| #include <linux/kfence.h> |
| |
| #include <asm/pgalloc.h> |
| #include <asm/set_memory.h> |
| |
| static inline int split_pmd_page(pmd_t *pmd, unsigned long addr) |
| { |
| int i; |
| unsigned long pfn = PFN_DOWN(__pa(addr)); |
| pte_t *pte = pte_alloc_one_kernel(&init_mm); |
| |
| if (!pte) |
| return -ENOMEM; |
| |
| for (i = 0; i < PTRS_PER_PTE; i++) |
| set_pte_ext(pte + i, pfn_pte(pfn + i, PAGE_KERNEL), 0); |
| pmd_populate_kernel(&init_mm, pmd, pte); |
| |
| flush_tlb_kernel_range(addr, addr + PMD_SIZE); |
| return 0; |
| } |
| |
| static inline bool arch_kfence_init_pool(void) |
| { |
| unsigned long addr; |
| pmd_t *pmd; |
| |
| for (addr = (unsigned long)__kfence_pool; is_kfence_address((void *)addr); |
| addr += PAGE_SIZE) { |
| pmd = pmd_off_k(addr); |
| |
| if (pmd_leaf(*pmd)) { |
| if (split_pmd_page(pmd, addr & PMD_MASK)) |
| return false; |
| } |
| } |
| |
| return true; |
| } |
| |
| static inline bool kfence_protect_page(unsigned long addr, bool protect) |
| { |
| set_memory_valid(addr, 1, !protect); |
| |
| return true; |
| } |
| |
| #endif /* __ASM_ARM_KFENCE_H */ |
