xref: /linux/arch/powerpc/include/asm/kfence.h (revision 4b132aacb0768ac1e652cf517097ea6f237214b9)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * powerpc KFENCE support.
4  *
5  * Copyright (C) 2020 CS GROUP France
6  */
7 
8 #ifndef __ASM_POWERPC_KFENCE_H
9 #define __ASM_POWERPC_KFENCE_H
10 
11 #include <linux/mm.h>
12 #include <asm/pgtable.h>
13 
14 #ifdef CONFIG_PPC64_ELF_ABI_V1
15 #define ARCH_FUNC_PREFIX "."
16 #endif
17 
18 #ifdef CONFIG_KFENCE
19 extern bool kfence_disabled;
20 
21 static inline void disable_kfence(void)
22 {
23 	kfence_disabled = true;
24 }
25 
26 static inline bool arch_kfence_init_pool(void)
27 {
28 	return !kfence_disabled;
29 }
30 #endif
31 
32 #ifdef CONFIG_PPC64
33 static inline bool kfence_protect_page(unsigned long addr, bool protect)
34 {
35 	struct page *page = virt_to_page((void *)addr);
36 
37 	__kernel_map_pages(page, 1, !protect);
38 
39 	return true;
40 }
41 #else
42 static inline bool kfence_protect_page(unsigned long addr, bool protect)
43 {
44 	pte_t *kpte = virt_to_kpte(addr);
45 
46 	if (protect) {
47 		pte_update(&init_mm, addr, kpte, _PAGE_PRESENT, 0, 0);
48 		flush_tlb_kernel_range(addr, addr + PAGE_SIZE);
49 	} else {
50 		pte_update(&init_mm, addr, kpte, 0, _PAGE_PRESENT, 0);
51 	}
52 
53 	return true;
54 }
55 #endif
56 
57 #endif /* __ASM_POWERPC_KFENCE_H */
58