2015-08-10 9:01 GMT+03:00 Aneesh Kumar K.V [off-list ref]:

Andrey Ryabinin [off-list ref] writes:

quoted

Introduce generic kasan_populate_zero_shadow(start, end).
This function maps kasan_zero_page to the [start, end] addresses.

In follow on patches it will be used for ARMv8 (and maybe other
architectures) and will replace x86_64 specific populate_zero_shadow().

Signed-off-by: Andrey Ryabinin <redacted>

This assume that we can have shared pgtable_t in generic code ? Is that
true for generic code ? Even if it is we may want to allow some arch to
override this ? On ppc64, we store the hardware hash page table slot
number in pte_t, Hence we won't be able to share pgtable_t.

So, ppc64 could define some config which will disable compilation of
mm/kasan/kasan_init.c.
However, it might be a bad idea to use such never defined config symbol now.
So I think this could be done later, in "KASAN for powerpc" series.

quoted

---
 arch/x86/mm/kasan_init_64.c |  14 ----
 include/linux/kasan.h       |   8 +++
 mm/kasan/Makefile           |   2 +-
 mm/kasan/kasan_init.c       | 151 ++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 160 insertions(+), 15 deletions(-)
 create mode 100644 mm/kasan/kasan_init.c

diff --git a/arch/x86/mm/kasan_init_64.c b/arch/x86/mm/kasan_init_64.c
index e1840f3..812086c 100644
--- a/arch/x86/mm/kasan_init_64.c
+++ b/arch/x86/mm/kasan_init_64.c

@@ -12,20 +12,6 @@
 extern pgd_t early_level4_pgt[PTRS_PER_PGD];
 extern struct range pfn_mapped[E820_X_MAX];

-static pud_t kasan_zero_pud[PTRS_PER_PUD] __page_aligned_bss;
-static pmd_t kasan_zero_pmd[PTRS_PER_PMD] __page_aligned_bss;
-static pte_t kasan_zero_pte[PTRS_PER_PTE] __page_aligned_bss;
-
-/*

-aneesh