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 (865B)

      1/* SPDX-License-Identifier: GPL-2.0 */
      2/*
      3 * PA-RISC KFENCE support.
      4 *
      5 * Copyright (C) 2021, Helge Deller <deller@gmx.de>
      6 */
      7
      8#ifndef _ASM_PARISC_KFENCE_H
      9#define _ASM_PARISC_KFENCE_H
     10
     11#include <linux/kfence.h>
     12
     13#include <asm/pgtable.h>
     14#include <asm/tlbflush.h>
     15
     16static inline bool arch_kfence_init_pool(void)
     17{
     18	return true;
     19}
     20
     21/* Protect the given page and flush TLB. */
     22static inline bool kfence_protect_page(unsigned long addr, bool protect)
     23{
     24	pte_t *pte = virt_to_kpte(addr);
     25
     26	if (WARN_ON(!pte))
     27		return false;
     28
     29	/*
     30	 * We need to avoid IPIs, as we may get KFENCE allocations or faults
     31	 * with interrupts disabled.
     32	 */
     33
     34	if (protect)
     35		set_pte(pte, __pte(pte_val(*pte) & ~_PAGE_PRESENT));
     36	else
     37		set_pte(pte, __pte(pte_val(*pte) | _PAGE_PRESENT));
     38
     39	flush_tlb_kernel_range(addr, addr + PAGE_SIZE);
     40
     41	return true;
     42}
     43
     44#endif /* _ASM_PARISC_KFENCE_H */