tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
fork
Configure Feed
Select the types of activity you want to include in your feed.
1/* SPDX-License-Identifier: GPL-2.0 */
2
3#ifndef _ASM_RISCV_KFENCE_H
4#define _ASM_RISCV_KFENCE_H
5
6#include <linux/kfence.h>
7#include <linux/pfn.h>
8#include <asm-generic/pgalloc.h>
9#include <asm/pgtable.h>
10
11static inline int split_pmd_page(unsigned long addr)
12{
13 int i;
14 unsigned long pfn = PFN_DOWN(__pa((addr & PMD_MASK)));
15 pmd_t *pmd = pmd_off_k(addr);
16 pte_t *pte = pte_alloc_one_kernel(&init_mm);
17
18 if (!pte)
19 return -ENOMEM;
20
21 for (i = 0; i < PTRS_PER_PTE; i++)
22 set_pte(pte + i, pfn_pte(pfn + i, PAGE_KERNEL));
23 set_pmd(pmd, pfn_pmd(PFN_DOWN(__pa(pte)), PAGE_TABLE));
24
25 flush_tlb_kernel_range(addr, addr + PMD_SIZE);
26 return 0;
27}
28
29static inline bool arch_kfence_init_pool(void)
30{
31 int ret;
32 unsigned long addr;
33 pmd_t *pmd;
34
35 for (addr = (unsigned long)__kfence_pool; is_kfence_address((void *)addr);
36 addr += PAGE_SIZE) {
37 pmd = pmd_off_k(addr);
38
39 if (pmd_leaf(*pmd)) {
40 ret = split_pmd_page(addr);
41 if (ret)
42 return false;
43 }
44 }
45
46 return true;
47}
48
49static inline bool kfence_protect_page(unsigned long addr, bool protect)
50{
51 pte_t *pte = virt_to_kpte(addr);
52
53 if (protect)
54 set_pte(pte, __pte(pte_val(*pte) & ~_PAGE_PRESENT));
55 else
56 set_pte(pte, __pte(pte_val(*pte) | _PAGE_PRESENT));
57
58 flush_tlb_kernel_range(addr, addr + PAGE_SIZE);
59
60 return true;
61}
62
63#endif /* _ASM_RISCV_KFENCE_H */