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authorJoonsoo Kim <iamjoonsoo.kim@lge.com>2017-05-31 09:17:26 +1000
committerStephen Rothwell <sfr@canb.auug.org.au>2017-06-01 08:44:25 +1000
commit607f3edc027530f1d66fba3e3724ee21287aa706 (patch)
tree4e2c142315c58959b5d2e2d2f83f0fb6ce4ea3c4 /mm
parent608916b2bede8b5daaef21f3f9cb6bba523c2253 (diff)
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>
Diffstat (limited to 'mm')
-rw-r--r--mm/kasan/kasan_init.c12
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,