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 *kaddr, *vaddr; 20 char *kfence_pool = __kfence_pool; 21 struct vm_struct *area; 22 23 area = __get_vm_area_caller(KFENCE_POOL_SIZE, VM_IOREMAP, 24 KFENCE_AREA_START, KFENCE_AREA_END, 25 __builtin_return_address(0)); 26 if (!area) 27 return false; 28 29 __kfence_pool = (char *)area->addr; 30 err = ioremap_page_range((unsigned long)__kfence_pool, 31 (unsigned long)__kfence_pool + KFENCE_POOL_SIZE, 32 virt_to_phys((void *)kfence_pool), PAGE_KERNEL); 33 if (err) { 34 free_vm_area(area); 35 __kfence_pool = kfence_pool; 36 return false; 37 } 38 39 kaddr = kfence_pool; 40 vaddr = __kfence_pool; 41 while (kaddr < kfence_pool + KFENCE_POOL_SIZE) { 42 set_page_address(virt_to_page(kaddr), vaddr); 43 kaddr += PAGE_SIZE; 44 vaddr += PAGE_SIZE; 45 } 46 47 return true; 48 } 49 50 /* Protect the given page and flush TLB. */ 51 static inline bool kfence_protect_page(unsigned long addr, bool protect) 52 { 53 pte_t *pte = virt_to_kpte(addr); 54 55 if (WARN_ON(!pte) || pte_none(*pte)) 56 return false; 57 58 if (protect) 59 set_pte(pte, __pte(pte_val(*pte) & ~(_PAGE_VALID | _PAGE_PRESENT))); 60 else 61 set_pte(pte, __pte(pte_val(*pte) | (_PAGE_VALID | _PAGE_PRESENT))); 62 63 preempt_disable(); 64 local_flush_tlb_one(addr); 65 preempt_enable(); 66 67 return true; 68 } 69 70 #endif /* _ASM_LOONGARCH_KFENCE_H */ 71