shinys000114/linux
1
0
Fork 0
mirror of https://github.com/hardkernel/linux.git synced 2026-06-08 03:40:35 +09:00
Code Issues Packages Projects Releases Wiki Activity

BACKPORT: kasan: initialize shadow to 0xff for tag-based mode

Browse Source 
Use kasan_alloc_zeroed_page instead of defining kasan_alloc_raw_page.

(Upstream commit 080eb83f54).

A tag-based KASAN shadow memory cell contains a memory tag, that
corresponds to the tag in the top byte of the pointer, that points to that
memory.  The native top byte value of kernel pointers is 0xff, so with
tag-based KASAN we need to initialize shadow memory to 0xff.

[cai@lca.pw: arm64: skip kmemleak for KASAN again\
  Link: http://lkml.kernel.org/r/20181226020550.63712-1-cai@lca.pw
Link: http://lkml.kernel.org/r/5cc1b789aad7c99cf4f3ec5b328b147ad53edb40.1544099024.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Bug: 128674696
Change-Id: I370390e529de29fee99820f3ae2fc3d0408379ef
This commit is contained in:
Andrey Konovalov
2018-12-28 00:30:09 -08:00
committed by Alistair Delva
parent 02e8a3fcb0
commit fe1cf9c054
3 changed files with 13 additions and 2 deletions
Download Patch File Download Diff File Expand all files Collapse all files

4
arch/arm64/mm/kasan_init.c
View File

@@ -94,6 +94,8 @@ static void __init kasan_pte_populate(pmd_t *pmdp, unsigned long addr,
phys_addr_t page_phys = early ?
__pa_symbol(kasan_early_shadow_page)
: kasan_alloc_zeroed_page(node);
if (!early)
memset(__va(page_phys), KASAN_SHADOW_INIT, PAGE_SIZE);
next = addr + PAGE_SIZE;
set_pte(ptep, pfn_pte(__phys_to_pfn(page_phys), PAGE_KERNEL));
} while (ptep++, addr = next, addr != end && pte_none(READ_ONCE(*ptep)));
@@ -240,7 +242,7 @@ void __init kasan_init(void)
pfn_pte(sym_to_pfn(kasan_early_shadow_page),
PAGE_KERNEL_RO));
memset(kasan_early_shadow_page, 0, PAGE_SIZE);
memset(kasan_early_shadow_page, KASAN_SHADOW_INIT, PAGE_SIZE);
cpu_replace_ttbr1(lm_alias(swapper_pg_dir));
/* At this point kasan is fully initialized. Enable error messages */

8
include/linux/kasan.h
View File

@@ -153,6 +153,8 @@ static inline size_t kasan_metadata_size(struct kmem_cache *cache) { return 0; }
#ifdef CONFIG_KASAN_GENERIC
#define KASAN_SHADOW_INIT 0
void kasan_cache_shrink(struct kmem_cache *cache);
void kasan_cache_shutdown(struct kmem_cache *cache);
@@ -163,4 +165,10 @@ static inline void kasan_cache_shutdown(struct kmem_cache *cache) {}
#endif /* CONFIG_KASAN_GENERIC */
#ifdef CONFIG_KASAN_SW_TAGS
#define KASAN_SHADOW_INIT 0xFF
#endif /* CONFIG_KASAN_SW_TAGS */
#endif /* LINUX_KASAN_H */

3
mm/kasan/common.c
View File

@@ -473,11 +473,12 @@ int kasan_module_alloc(void *addr, size_t size)
ret = __vmalloc_node_range(shadow_size, 1, shadow_start,
shadow_start + shadow_size,
GFP_KERNEL | __GFP_ZERO,
GFP_KERNEL,
PAGE_KERNEL, VM_NO_GUARD, NUMA_NO_NODE,
__builtin_return_address(0));
if (ret) {
__memset(ret, KASAN_SHADOW_INIT, shadow_size);
find_vm_area(addr)->flags |= VM_KASAN;
kmemleak_ignore(ret);
return 0;