[PATCHv7 05/11] mm/kasan: Switch to using __pa_symbol and lm_alias

From: Laura Abbott
Date: Tue Jan 10 2017 - 16:36:30 EST



__pa_symbol is the correct API to find the physical address of symbols.
Switch to it to allow for debugging APIs to work correctly. Other
functions such as p*d_populate may call __pa internally. Ensure that the
address passed is in the linear region by calling lm_alias.

Reviewed-by: Mark Rutland <mark.rutland@xxxxxxx>
Tested-by: Mark Rutland <mark.rutland@xxxxxxx>
Signed-off-by: Laura Abbott <labbott@xxxxxxxxxx>
---
mm/kasan/kasan_init.c | 15 ++++++++-------
1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/mm/kasan/kasan_init.c b/mm/kasan/kasan_init.c
index 3f9a41c..31238da 100644
--- a/mm/kasan/kasan_init.c
+++ b/mm/kasan/kasan_init.c
@@ -15,6 +15,7 @@
#include <linux/kasan.h>
#include <linux/kernel.h>
#include <linux/memblock.h>
+#include <linux/mm.h>
#include <linux/pfn.h>

#include <asm/page.h>
@@ -49,7 +50,7 @@ static void __init zero_pte_populate(pmd_t *pmd, unsigned long addr,
pte_t *pte = pte_offset_kernel(pmd, addr);
pte_t zero_pte;

- zero_pte = pfn_pte(PFN_DOWN(__pa(kasan_zero_page)), PAGE_KERNEL);
+ zero_pte = pfn_pte(PFN_DOWN(__pa_symbol(kasan_zero_page)), PAGE_KERNEL);
zero_pte = pte_wrprotect(zero_pte);

while (addr + PAGE_SIZE <= end) {
@@ -69,7 +70,7 @@ static void __init zero_pmd_populate(pud_t *pud, unsigned long addr,
next = pmd_addr_end(addr, end);

if (IS_ALIGNED(addr, PMD_SIZE) && end - addr >= PMD_SIZE) {
- pmd_populate_kernel(&init_mm, pmd, kasan_zero_pte);
+ pmd_populate_kernel(&init_mm, pmd, lm_alias(kasan_zero_pte));
continue;
}

@@ -92,9 +93,9 @@ static void __init zero_pud_populate(pgd_t *pgd, unsigned long addr,
if (IS_ALIGNED(addr, PUD_SIZE) && end - addr >= PUD_SIZE) {
pmd_t *pmd;

- pud_populate(&init_mm, pud, kasan_zero_pmd);
+ pud_populate(&init_mm, pud, lm_alias(kasan_zero_pmd));
pmd = pmd_offset(pud, addr);
- pmd_populate_kernel(&init_mm, pmd, kasan_zero_pte);
+ pmd_populate_kernel(&init_mm, pmd, lm_alias(kasan_zero_pte));
continue;
}

@@ -135,11 +136,11 @@ void __init kasan_populate_zero_shadow(const void *shadow_start,
* puds,pmds, so pgd_populate(), pud_populate()
* is noops.
*/
- pgd_populate(&init_mm, pgd, kasan_zero_pud);
+ pgd_populate(&init_mm, pgd, lm_alias(kasan_zero_pud));
pud = pud_offset(pgd, addr);
- pud_populate(&init_mm, pud, kasan_zero_pmd);
+ pud_populate(&init_mm, pud, lm_alias(kasan_zero_pmd));
pmd = pmd_offset(pud, addr);
- pmd_populate_kernel(&init_mm, pmd, kasan_zero_pte);
+ pmd_populate_kernel(&init_mm, pmd, lm_alias(kasan_zero_pte));
continue;
}

--
2.7.4