Commit 7ba149ff authored by Sean Christopherson's avatar Sean Christopherson Committed by Jialin Zhang
Browse files

x86/kasan: Add helpers to align shadow addresses up and down 

mainline inclusion
from mainline-v6.2-rc1
commit bde258d9
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/I6C6UC
CVE: CVE-2023-0597

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=bde258d97409f2a45243cb393a55ea9ecfc7aba5



--------------------------------

Add helpers to dedup code for aligning shadow address up/down to page
boundaries when translating an address to its shadow.

No functional change intended.

Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: default avatarAndrey Ryabinin <ryabinin.a.a@gmail.com>
Link: https://lkml.kernel.org/r/20221110203504.1985010-5-seanjc@google.com


Signed-off-by: default avatarTong Tiangen <tongtiangen@huawei.com>
Reviewed-by: default avatarWang Weiyang <wangweiyang2@huawei.com>
Reviewed-by: default avatarKefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: default avatarJialin Zhang <zhangjialin11@huawei.com>
parent d8e31b4b

arch/x86/mm/kasan_init_64.c

+22 −18
Original line number Diff line number Diff line
@@ -318,22 +318,33 @@ void __init kasan_early_init(void) 
	kasan_map_early_shadow(init_top_pgt);

}



static unsigned long kasan_mem_to_shadow_align_down(unsigned long va)

{

	unsigned long shadow = (unsigned long)kasan_mem_to_shadow((void *)va);



	return round_down(shadow, PAGE_SIZE);

}



static unsigned long kasan_mem_to_shadow_align_up(unsigned long va)

{

	unsigned long shadow = (unsigned long)kasan_mem_to_shadow((void *)va);



	return round_up(shadow, PAGE_SIZE);

}



void __init kasan_populate_shadow_for_vaddr(void *va, size_t size, int nid)

{

	unsigned long shadow_start, shadow_end;



	shadow_start = (unsigned long)kasan_mem_to_shadow(va);

	shadow_start = round_down(shadow_start, PAGE_SIZE);

	shadow_end = (unsigned long)kasan_mem_to_shadow(va + size);

	shadow_end = round_up(shadow_end, PAGE_SIZE);



	shadow_start = kasan_mem_to_shadow_align_down((unsigned long)va);

	shadow_end = kasan_mem_to_shadow_align_up((unsigned long)va + size);

	kasan_populate_shadow(shadow_start, shadow_end, nid);

}



void __init kasan_init(void)

{

	unsigned long shadow_cea_begin, shadow_cea_end;

	int i;

	void *shadow_cea_begin, *shadow_cea_end;



	memcpy(early_top_pgt, init_top_pgt, sizeof(early_top_pgt));
@@ -374,16 +385,9 @@ void __init kasan_init(void) 
		map_range(&pfn_mapped[i]);

	}



	shadow_cea_begin = (void *)CPU_ENTRY_AREA_BASE;

	shadow_cea_begin = kasan_mem_to_shadow(shadow_cea_begin);

	shadow_cea_begin = (void *)round_down(

			(unsigned long)shadow_cea_begin, PAGE_SIZE);



	shadow_cea_end = (void *)(CPU_ENTRY_AREA_BASE +

	shadow_cea_begin = kasan_mem_to_shadow_align_down(CPU_ENTRY_AREA_BASE);

	shadow_cea_end = kasan_mem_to_shadow_align_up(CPU_ENTRY_AREA_BASE +

						      CPU_ENTRY_AREA_MAP_SIZE);

	shadow_cea_end = kasan_mem_to_shadow(shadow_cea_end);

	shadow_cea_end = (void *)round_up(

			(unsigned long)shadow_cea_end, PAGE_SIZE);



	kasan_populate_early_shadow(

		kasan_mem_to_shadow((void *)PAGE_OFFSET + MAXMEM),
@@ -405,9 +409,9 @@ void __init kasan_init(void) 


	kasan_populate_early_shadow(

		kasan_mem_to_shadow((void *)VMALLOC_END + 1),

		shadow_cea_begin);

		(void *)shadow_cea_begin);



	kasan_populate_early_shadow(shadow_cea_end,

	kasan_populate_early_shadow((void *)shadow_cea_end,

			kasan_mem_to_shadow((void *)__START_KERNEL_map));



	kasan_populate_shadow((unsigned long)kasan_mem_to_shadow(_stext),