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
arch_kfence_init_pool(void)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. */
kfence_protect_page(unsigned long addr,bool protect)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