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| author | Joonsoo Kim <iamjoonsoo.kim@lge.com> | 2017-07-10 15:50:21 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-07-10 16:32:33 -0700 |
| commit | 458f7920f9b1e6c313944d498c440f8599b8a136 (patch) | |
| tree | cf0b95059db4f4eda086e8c82b5b12646c2444d3 /mm | |
| parent | cf8e0fedf0784ef4bc1889380b09eda295e3d109 (diff) | |
| download | lwn-458f7920f9b1e6c313944d498c440f8599b8a136.tar.gz lwn-458f7920f9b1e6c313944d498c440f8599b8a136.zip | |
mm/kasan/kasan_init.c: use kasan_zero_pud for p4d table
There is missing optimization in zero_p4d_populate() that can save some
memory when mapping zero shadow. Implement it like as others.
Link: http://lkml.kernel.org/r/1494829255-23946-1-git-send-email-iamjoonsoo.kim@lge.com
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/kasan/kasan_init.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/mm/kasan/kasan_init.c b/mm/kasan/kasan_init.c index b96a5f773d88..554e4c0f23a2 100644 --- a/mm/kasan/kasan_init.c +++ b/mm/kasan/kasan_init.c @@ -118,6 +118,18 @@ static void __init zero_p4d_populate(pgd_t *pgd, unsigned long addr, do { next = p4d_addr_end(addr, end); + if (IS_ALIGNED(addr, P4D_SIZE) && end - addr >= P4D_SIZE) { + pud_t *pud; + pmd_t *pmd; + + p4d_populate(&init_mm, p4d, lm_alias(kasan_zero_pud)); + pud = pud_offset(p4d, addr); + pud_populate(&init_mm, pud, lm_alias(kasan_zero_pmd)); + pmd = pmd_offset(pud, addr); + pmd_populate_kernel(&init_mm, pmd, + lm_alias(kasan_zero_pte)); + continue; + } if (p4d_none(*p4d)) { p4d_populate(&init_mm, p4d, |