cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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kfence.h (1058B)

      1/* SPDX-License-Identifier: GPL-2.0 */
      2
      3#ifndef __ASM_ARM_KFENCE_H
      4#define __ASM_ARM_KFENCE_H
      5
      6#include <linux/kfence.h>
      7
      8#include <asm/pgalloc.h>
      9#include <asm/set_memory.h>
     10
     11static inline int split_pmd_page(pmd_t *pmd, unsigned long addr)
     12{
     13	int i;
     14	unsigned long pfn = PFN_DOWN(__pa(addr));
     15	pte_t *pte = pte_alloc_one_kernel(&init_mm);
     16
     17	if (!pte)
     18		return -ENOMEM;
     19
     20	for (i = 0; i < PTRS_PER_PTE; i++)
     21		set_pte_ext(pte + i, pfn_pte(pfn + i, PAGE_KERNEL), 0);
     22	pmd_populate_kernel(&init_mm, pmd, pte);
     23
     24	flush_tlb_kernel_range(addr, addr + PMD_SIZE);
     25	return 0;
     26}
     27
     28static inline bool arch_kfence_init_pool(void)
     29{
     30	unsigned long addr;
     31	pmd_t *pmd;
     32
     33	for (addr = (unsigned long)__kfence_pool; is_kfence_address((void *)addr);
     34	     addr += PAGE_SIZE) {
     35		pmd = pmd_off_k(addr);
     36
     37		if (pmd_leaf(*pmd)) {
     38			if (split_pmd_page(pmd, addr & PMD_MASK))
     39				return false;
     40		}
     41	}
     42
     43	return true;
     44}
     45
     46static inline bool kfence_protect_page(unsigned long addr, bool protect)
     47{
     48	set_memory_valid(addr, 1, !protect);
     49
     50	return true;
     51}
     52
     53#endif /* __ASM_ARM_KFENCE_H */