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 <linux/vmalloc.h> 14 #include <asm/pgtable.h> 15 #include <asm/tlb.h> 16 17 static inline bool arch_kfence_init_pool(void) 18 { 19 int err; 20 char *kaddr, *vaddr; 21 char *kfence_pool = __kfence_pool; 22 struct vm_struct *area; 23 24 area = __get_vm_area_caller(KFENCE_POOL_SIZE, VM_IOREMAP, 25 KFENCE_AREA_START, KFENCE_AREA_END, 26 __builtin_return_address(0)); 27 if (!area) 28 return false; 29 30 __kfence_pool = (char *)area->addr; 31 err = ioremap_page_range((unsigned long)__kfence_pool, 32 (unsigned long)__kfence_pool + KFENCE_POOL_SIZE, 33 virt_to_phys((void *)kfence_pool), PAGE_KERNEL); 34 if (err) { 35 free_vm_area(area); 36 __kfence_pool = kfence_pool; 37 return false; 38 } 39 40 kaddr = kfence_pool; 41 vaddr = __kfence_pool; 42 while (kaddr < kfence_pool + KFENCE_POOL_SIZE) { 43 set_page_address(virt_to_page(kaddr), vaddr); 44 kaddr += PAGE_SIZE; 45 vaddr += PAGE_SIZE; 46 } 47 48 return true; 49 } 50 51 /* Protect the given page and flush TLB. */ 52 static inline bool kfence_protect_page(unsigned long addr, bool protect) 53 { 54 pte_t *pte = virt_to_kpte(addr); 55 56 if (WARN_ON(!pte) || pte_none(ptep_get(pte))) 57 return false; 58 59 if (protect) 60 set_pte(pte, __pte(pte_val(ptep_get(pte)) & ~(_PAGE_VALID | _PAGE_PRESENT))); 61 else 62 set_pte(pte, __pte(pte_val(ptep_get(pte)) | (_PAGE_VALID | _PAGE_PRESENT))); 63 64 preempt_disable(); 65 local_flush_tlb_one(addr); 66 preempt_enable(); 67 68 return true; 69 } 70 71 #endif /* _ASM_LOONGARCH_KFENCE_H */ 72