64 lines
1.3 KiB
C
64 lines
1.3 KiB
C
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/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _ASM_RISCV_KFENCE_H
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#define _ASM_RISCV_KFENCE_H
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#include <linux/kfence.h>
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#include <linux/pfn.h>
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#include <asm-generic/pgalloc.h>
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#include <asm/pgtable.h>
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static inline int split_pmd_page(unsigned long addr)
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{
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int i;
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unsigned long pfn = PFN_DOWN(__pa((addr & PMD_MASK)));
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pmd_t *pmd = pmd_off_k(addr);
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pte_t *pte = pte_alloc_one_kernel(&init_mm);
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if (!pte)
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return -ENOMEM;
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for (i = 0; i < PTRS_PER_PTE; i++)
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set_pte(pte + i, pfn_pte(pfn + i, PAGE_KERNEL));
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set_pmd(pmd, pfn_pmd(PFN_DOWN(__pa(pte)), PAGE_TABLE));
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flush_tlb_kernel_range(addr, addr + PMD_SIZE);
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return 0;
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}
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static inline bool arch_kfence_init_pool(void)
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{
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int ret;
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unsigned long addr;
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pmd_t *pmd;
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for (addr = (unsigned long)__kfence_pool; is_kfence_address((void *)addr);
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addr += PAGE_SIZE) {
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pmd = pmd_off_k(addr);
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if (pmd_leaf(*pmd)) {
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ret = split_pmd_page(addr);
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if (ret)
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return false;
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}
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}
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return true;
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}
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static inline bool kfence_protect_page(unsigned long addr, bool protect)
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{
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pte_t *pte = virt_to_kpte(addr);
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if (protect)
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set_pte(pte, __pte(pte_val(*pte) & ~_PAGE_PRESENT));
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else
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set_pte(pte, __pte(pte_val(*pte) | _PAGE_PRESENT));
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flush_tlb_kernel_range(addr, addr + PAGE_SIZE);
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return true;
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}
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#endif /* _ASM_RISCV_KFENCE_H */
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