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| author | Andrey Konovalov <andreyknvl@google.com> | 2018-12-28 00:30:09 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-12-28 12:11:43 -0800 |
| commit | 080eb83f54cf5b96ae5b6ce3c1896e35c341aff9 (patch) | |
| tree | 5104bee028d891c8072b6606b0515c78413af896 /mm/kasan | |
| parent | 9577dd7486487722ed8f0773243223f108e8089f (diff) | |
| download | lwn-080eb83f54cf5b96ae5b6ce3c1896e35c341aff9.tar.gz lwn-080eb83f54cf5b96ae5b6ce3c1896e35c341aff9.zip | |
kasan: initialize shadow to 0xff for tag-based mode
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>
Diffstat (limited to 'mm/kasan')
| -rw-r--r-- | mm/kasan/common.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/mm/kasan/common.c b/mm/kasan/common.c index 5f68c93734ba..7134e75447ff 100644 --- a/mm/kasan/common.c +++ b/mm/kasan/common.c @@ -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; |