linux/arch/riscv/mm/kasan_init.c
Vincent Chen 4cb699d044
riscv: kasan: use local_tlb_flush_all() to avoid uninitialized __sbi_rfence
It fails to boot the v5.8-rc4 kernel with CONFIG_KASAN because kasan_init
and kasan_early_init use uninitialized __sbi_rfence as executing the
tlb_flush_all(). Actually, at this moment, only the CPU which is
responsible for the system initialization enables the MMU. Other CPUs are
parking at the .Lsecondary_start. Hence the tlb_flush_all() is able to be
replaced by local_tlb_flush_all() to avoid using uninitialized
__sbi_rfence.

Signed-off-by: Vincent Chen <vincent.chen@sifive.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-07-20 21:14:51 -07:00

114 lines
3.1 KiB
C

// SPDX-License-Identifier: GPL-2.0
// Copyright (C) 2019 Andes Technology Corporation
#include <linux/pfn.h>
#include <linux/init_task.h>
#include <linux/kasan.h>
#include <linux/kernel.h>
#include <linux/memblock.h>
#include <linux/pgtable.h>
#include <asm/tlbflush.h>
#include <asm/fixmap.h>
extern pgd_t early_pg_dir[PTRS_PER_PGD];
asmlinkage void __init kasan_early_init(void)
{
uintptr_t i;
pgd_t *pgd = early_pg_dir + pgd_index(KASAN_SHADOW_START);
for (i = 0; i < PTRS_PER_PTE; ++i)
set_pte(kasan_early_shadow_pte + i,
mk_pte(virt_to_page(kasan_early_shadow_page),
PAGE_KERNEL));
for (i = 0; i < PTRS_PER_PMD; ++i)
set_pmd(kasan_early_shadow_pmd + i,
pfn_pmd(PFN_DOWN
(__pa((uintptr_t) kasan_early_shadow_pte)),
__pgprot(_PAGE_TABLE)));
for (i = KASAN_SHADOW_START; i < KASAN_SHADOW_END;
i += PGDIR_SIZE, ++pgd)
set_pgd(pgd,
pfn_pgd(PFN_DOWN
(__pa(((uintptr_t) kasan_early_shadow_pmd))),
__pgprot(_PAGE_TABLE)));
/* init for swapper_pg_dir */
pgd = pgd_offset_k(KASAN_SHADOW_START);
for (i = KASAN_SHADOW_START; i < KASAN_SHADOW_END;
i += PGDIR_SIZE, ++pgd)
set_pgd(pgd,
pfn_pgd(PFN_DOWN
(__pa(((uintptr_t) kasan_early_shadow_pmd))),
__pgprot(_PAGE_TABLE)));
local_flush_tlb_all();
}
static void __init populate(void *start, void *end)
{
unsigned long i, offset;
unsigned long vaddr = (unsigned long)start & PAGE_MASK;
unsigned long vend = PAGE_ALIGN((unsigned long)end);
unsigned long n_pages = (vend - vaddr) / PAGE_SIZE;
unsigned long n_ptes =
((n_pages + PTRS_PER_PTE) & -PTRS_PER_PTE) / PTRS_PER_PTE;
unsigned long n_pmds =
((n_ptes + PTRS_PER_PMD) & -PTRS_PER_PMD) / PTRS_PER_PMD;
pte_t *pte =
memblock_alloc(n_ptes * PTRS_PER_PTE * sizeof(pte_t), PAGE_SIZE);
pmd_t *pmd =
memblock_alloc(n_pmds * PTRS_PER_PMD * sizeof(pmd_t), PAGE_SIZE);
pgd_t *pgd = pgd_offset_k(vaddr);
for (i = 0; i < n_pages; i++) {
phys_addr_t phys = memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE);
set_pte(&pte[i], pfn_pte(PHYS_PFN(phys), PAGE_KERNEL));
}
for (i = 0, offset = 0; i < n_ptes; i++, offset += PTRS_PER_PTE)
set_pmd(&pmd[i],
pfn_pmd(PFN_DOWN(__pa(&pte[offset])),
__pgprot(_PAGE_TABLE)));
for (i = 0, offset = 0; i < n_pmds; i++, offset += PTRS_PER_PMD)
set_pgd(&pgd[i],
pfn_pgd(PFN_DOWN(__pa(&pmd[offset])),
__pgprot(_PAGE_TABLE)));
local_flush_tlb_all();
memset(start, 0, end - start);
}
void __init kasan_init(void)
{
struct memblock_region *reg;
unsigned long i;
kasan_populate_early_shadow((void *)KASAN_SHADOW_START,
(void *)kasan_mem_to_shadow((void *)
VMALLOC_END));
for_each_memblock(memory, reg) {
void *start = (void *)__va(reg->base);
void *end = (void *)__va(reg->base + reg->size);
if (start >= end)
break;
populate(kasan_mem_to_shadow(start), kasan_mem_to_shadow(end));
};
for (i = 0; i < PTRS_PER_PTE; i++)
set_pte(&kasan_early_shadow_pte[i],
mk_pte(virt_to_page(kasan_early_shadow_page),
__pgprot(_PAGE_PRESENT | _PAGE_READ |
_PAGE_ACCESSED)));
memset(kasan_early_shadow_page, 0, PAGE_SIZE);
init_task.kasan_depth = 0;
}