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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8xx.c (1891B)

      1// SPDX-License-Identifier: GPL-2.0
      2
      3#define DISABLE_BRANCH_PROFILING
      4
      5#include <linux/kasan.h>
      6#include <linux/memblock.h>
      7#include <linux/hugetlb.h>
      8
      9static int __init
     10kasan_init_shadow_8M(unsigned long k_start, unsigned long k_end, void *block)
     11{
     12	pmd_t *pmd = pmd_off_k(k_start);
     13	unsigned long k_cur, k_next;
     14
     15	for (k_cur = k_start; k_cur != k_end; k_cur = k_next, pmd += 2, block += SZ_8M) {
     16		pte_basic_t *new;
     17
     18		k_next = pgd_addr_end(k_cur, k_end);
     19		k_next = pgd_addr_end(k_next, k_end);
     20		if ((void *)pmd_page_vaddr(*pmd) != kasan_early_shadow_pte)
     21			continue;
     22
     23		new = memblock_alloc(sizeof(pte_basic_t), SZ_4K);
     24		if (!new)
     25			return -ENOMEM;
     26
     27		*new = pte_val(pte_mkhuge(pfn_pte(PHYS_PFN(__pa(block)), PAGE_KERNEL)));
     28
     29		hugepd_populate_kernel((hugepd_t *)pmd, (pte_t *)new, PAGE_SHIFT_8M);
     30		hugepd_populate_kernel((hugepd_t *)pmd + 1, (pte_t *)new, PAGE_SHIFT_8M);
     31	}
     32	return 0;
     33}
     34
     35int __init kasan_init_region(void *start, size_t size)
     36{
     37	unsigned long k_start = (unsigned long)kasan_mem_to_shadow(start);
     38	unsigned long k_end = (unsigned long)kasan_mem_to_shadow(start + size);
     39	unsigned long k_cur;
     40	int ret;
     41	void *block;
     42
     43	block = memblock_alloc(k_end - k_start, SZ_8M);
     44	if (!block)
     45		return -ENOMEM;
     46
     47	if (IS_ALIGNED(k_start, SZ_8M)) {
     48		kasan_init_shadow_8M(k_start, ALIGN_DOWN(k_end, SZ_8M), block);
     49		k_cur = ALIGN_DOWN(k_end, SZ_8M);
     50		if (k_cur == k_end)
     51			goto finish;
     52	} else {
     53		k_cur = k_start;
     54	}
     55
     56	ret = kasan_init_shadow_page_tables(k_start, k_end);
     57	if (ret)
     58		return ret;
     59
     60	for (; k_cur < k_end; k_cur += PAGE_SIZE) {
     61		pmd_t *pmd = pmd_off_k(k_cur);
     62		void *va = block + k_cur - k_start;
     63		pte_t pte = pfn_pte(PHYS_PFN(__pa(va)), PAGE_KERNEL);
     64
     65		if (k_cur < ALIGN_DOWN(k_end, SZ_512K))
     66			pte = pte_mkhuge(pte);
     67
     68		__set_pte_at(&init_mm, k_cur, pte_offset_kernel(pmd, k_cur), pte, 0);
     69	}
     70finish:
     71	flush_tlb_kernel_range(k_start, k_end);
     72	return 0;
     73}