Commit a4106566 authored by Huacai Chen's avatar Huacai Chen
Browse files

LoongArch: Make KASAN work with 5-level page-tables 



Make KASAN work with 5-level page-tables, including:
1. Implement and use __pgd_none() and kasan_p4d_offset().
2. As done in kasan_pmd_populate() and kasan_pte_populate(), restrict
   the loop conditions of kasan_p4d_populate() and kasan_pud_populate()
   to avoid unnecessary population.

Cc: stable@vger.kernel.org
Signed-off-by: default avatarHuacai Chen <chenhuacai@loongson.cn>
parent c859900a

arch/loongarch/mm/kasan_init.c

+23 −3
Original line number Diff line number Diff line
@@ -13,6 +13,13 @@ 


static pgd_t kasan_pg_dir[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE);



#ifdef __PAGETABLE_P4D_FOLDED

#define __pgd_none(early, pgd) (0)

#else

#define __pgd_none(early, pgd) (early ? (pgd_val(pgd) == 0) : \

(__pa(pgd_val(pgd)) == (unsigned long)__pa(kasan_early_shadow_p4d)))

#endif



#ifdef __PAGETABLE_PUD_FOLDED

#define __p4d_none(early, p4d) (0)

#else
@@ -142,6 +149,19 @@ static pud_t *__init kasan_pud_offset(p4d_t *p4dp, unsigned long addr, int node, 
	return pud_offset(p4dp, addr);

}



static p4d_t *__init kasan_p4d_offset(pgd_t *pgdp, unsigned long addr, int node, bool early)

{

	if (__pgd_none(early, pgdp_get(pgdp))) {

		phys_addr_t p4d_phys = early ?

			__pa_symbol(kasan_early_shadow_p4d) : kasan_alloc_zeroed_page(node);

		if (!early)

			memcpy(__va(p4d_phys), kasan_early_shadow_p4d, sizeof(kasan_early_shadow_p4d));

		pgd_populate(&init_mm, pgdp, (p4d_t *)__va(p4d_phys));

	}



	return p4d_offset(pgdp, addr);

}



static void __init kasan_pte_populate(pmd_t *pmdp, unsigned long addr,

				      unsigned long end, int node, bool early)

{
@@ -178,19 +198,19 @@ static void __init kasan_pud_populate(p4d_t *p4dp, unsigned long addr, 
	do {

		next = pud_addr_end(addr, end);

		kasan_pmd_populate(pudp, addr, next, node, early);

	} while (pudp++, addr = next, addr != end);

	} while (pudp++, addr = next, addr != end && __pud_none(early, READ_ONCE(*pudp)));

}



static void __init kasan_p4d_populate(pgd_t *pgdp, unsigned long addr,

					    unsigned long end, int node, bool early)

{

	unsigned long next;

	p4d_t *p4dp = p4d_offset(pgdp, addr);

	p4d_t *p4dp = kasan_p4d_offset(pgdp, addr, node, early);



	do {

		next = p4d_addr_end(addr, end);

		kasan_pud_populate(p4dp, addr, next, node, early);

	} while (p4dp++, addr = next, addr != end);

	} while (p4dp++, addr = next, addr != end && __p4d_none(early, READ_ONCE(*p4dp)));

}



static void __init kasan_pgd_populate(unsigned long addr, unsigned long end,