arch/powerpc/include/asm/kfence.h

   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 */