75969686ec
Add architecture specific implementation details for KFENCE and enable KFENCE on ARM. In particular, this implements the required interface in <asm/kfence.h>. KFENCE requires that attributes for pages from its memory pool can individually be set. Therefore, force the kfence pool to be mapped at page granularity. Testing this patch using the testcases in kfence_test.c and all passed with or without ARM_LPAE. Acked-by: Marco Elver <elver@google.com> Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
53 lines
1 KiB
C
53 lines
1 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef __ASM_ARM_KFENCE_H
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#define __ASM_ARM_KFENCE_H
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#include <linux/kfence.h>
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#include <asm/pgalloc.h>
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#include <asm/set_memory.h>
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static inline int split_pmd_page(pmd_t *pmd, unsigned long addr)
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{
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int i;
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unsigned long pfn = PFN_DOWN(__pa(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_ext(pte + i, pfn_pte(pfn + i, PAGE_KERNEL), 0);
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pmd_populate_kernel(&init_mm, pmd, pte);
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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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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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if (split_pmd_page(pmd, addr & PMD_MASK))
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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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set_memory_valid(addr, 1, !protect);
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return true;
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}
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#endif /* __ASM_ARM_KFENCE_H */
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