[PATCH v3] ARM: mm: report both sections from PMD

From: Kees Cook
Date: Thu Feb 13 2014 - 14:54:17 EST


On 2-level page table systems, the PMD has 2 section entries. Report
these, otherwise ARM_PTDUMP will miss reporting permission changes on
odd section boundaries.

Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
---
v3:
- re-reorganize, drop use of pmd_sect; suggested by Catalin Marinas.
v2:
- reorganize, suggested by Catalin Marinas.
---
arch/arm/mm/dump.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/arch/arm/mm/dump.c b/arch/arm/mm/dump.c
index 2b342177f5de..61cc78ae9f21 100644
--- a/arch/arm/mm/dump.c
+++ b/arch/arm/mm/dump.c
@@ -264,6 +264,9 @@ static void walk_pmd(struct pg_state *st, pud_t *pud, unsigned long start)
note_page(st, addr, 3, pmd_val(*pmd));
else
walk_pte(st, pmd, addr);
+
+ if (SECTION_SIZE < PMD_SIZE && pmd_large(pmd[1]))
+ note_page(st, addr + SECTION_SIZE, 3, pmd_val(pmd[1]));
}
}

--
1.7.9.5


--
Kees Cook
Chrome OS Security
--
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