1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* 3 * KFENCE support for LoongArch. 4 * 5 * Author: Enze Li <lienze@kylinos.cn> 6 * Copyright (C) 2022-2023 KylinSoft Corporation. 7 */ 8 9 #ifndef _ASM_LOONGARCH_KFENCE_H 10 #define _ASM_LOONGARCH_KFENCE_H 11 12 #include <linux/kfence.h> 13 #include <asm/pgtable.h> 14 #include <asm/tlb.h> 15 16 static inline bool arch_kfence_init_pool(void) 17 { 18 int err; 19 char *kfence_pool = __kfence_pool; 20 struct vm_struct *area; 21 22 area = __get_vm_area_caller(KFENCE_POOL_SIZE, VM_IOREMAP, 23 KFENCE_AREA_START, KFENCE_AREA_END, 24 __builtin_return_address(0)); 25 if (!area) 26 return false; 27 28 __kfence_pool = (char *)area->addr; 29 err = ioremap_page_range((unsigned long)__kfence_pool, 30 (unsigned long)__kfence_pool + KFENCE_POOL_SIZE, 31 virt_to_phys((void *)kfence_pool), PAGE_KERNEL); 32 if (err) { 33 free_vm_area(area); 34 __kfence_pool = kfence_pool; 35 return false; 36 } 37 38 return true; 39 } 40 41 /* Protect the given page and flush TLB. */ 42 static inline bool kfence_protect_page(unsigned long addr, bool protect) 43 { 44 pte_t *pte = virt_to_kpte(addr); 45 46 if (WARN_ON(!pte) || pte_none(*pte)) 47 return false; 48 49 if (protect) 50 set_pte(pte, __pte(pte_val(*pte) & ~(_PAGE_VALID | _PAGE_PRESENT))); 51 else 52 set_pte(pte, __pte(pte_val(*pte) | (_PAGE_VALID | _PAGE_PRESENT))); 53 54 preempt_disable(); 55 local_flush_tlb_one(addr); 56 preempt_enable(); 57 58 return true; 59 } 60 61 #endif /* _ASM_LOONGARCH_KFENCE_H */ 62