1 /* SPDX-License-Identifier: GPL-2.0 */
3 #ifndef _ASM_RISCV_KFENCE_H
4 #define _ASM_RISCV_KFENCE_H
6 #include <linux/kfence.h>
8 #include <asm-generic/pgalloc.h>
9 #include <asm/pgtable.h>
11 static inline int split_pmd_page(unsigned long addr)
14 unsigned long pfn = PFN_DOWN(__pa((addr & PMD_MASK)));
15 pmd_t *pmd = pmd_off_k(addr);
16 pte_t *pte = pte_alloc_one_kernel(&init_mm);
21 for (i = 0; i < PTRS_PER_PTE; i++)
22 set_pte(pte + i, pfn_pte(pfn + i, PAGE_KERNEL));
23 set_pmd(pmd, pfn_pmd(PFN_DOWN(__pa(pte)), PAGE_TABLE));
25 flush_tlb_kernel_range(addr, addr + PMD_SIZE);
29 static inline bool arch_kfence_init_pool(void)
35 for (addr = (unsigned long)__kfence_pool; is_kfence_address((void *)addr);
37 pmd = pmd_off_k(addr);
40 ret = split_pmd_page(addr);
49 static inline bool kfence_protect_page(unsigned long addr, bool protect)
51 pte_t *pte = virt_to_kpte(addr);
54 set_pte(pte, __pte(pte_val(*pte) & ~_PAGE_PRESENT));
56 set_pte(pte, __pte(pte_val(*pte) | _PAGE_PRESENT));
58 flush_tlb_kernel_range(addr, addr + PAGE_SIZE);
63 #endif /* _ASM_RISCV_KFENCE_H */