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 extern bool kfence_early_init; 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 31 static inline bool kfence_early_init_enabled(void) 32 { 33 return IS_ENABLED(CONFIG_KFENCE) && kfence_early_init; 34 } 35 36 #ifdef CONFIG_PPC64 37 static inline bool kfence_protect_page(unsigned long addr, bool protect) 38 { 39 struct page *page = virt_to_page((void *)addr); 40 41 __kernel_map_pages(page, 1, !protect); 42 43 return true; 44 } 45 #else 46 static inline bool kfence_protect_page(unsigned long addr, bool protect) 47 { 48 pte_t *kpte = virt_to_kpte(addr); 49 50 if (protect) { 51 pte_update(&init_mm, addr, kpte, _PAGE_PRESENT, 0, 0); 52 flush_tlb_kernel_range(addr, addr + PAGE_SIZE); 53 } else { 54 pte_update(&init_mm, addr, kpte, 0, _PAGE_PRESENT, 0); 55 } 56 57 return true; 58 } 59 #endif 60 61 #endif /* __ASM_POWERPC_KFENCE_H */ 62