3.7-stable review patch. If anyone has any objections, please let me know.
------------------
From: Will Deacon <will.dea...@arm.com>
commit 02522463c84748b3b8ad770f9424bcfa70a5b4c4 upstream.
Marking non-present ptes as read-only can corrupt file ptes, breaking
things like swap and file mappings.
This patch ensures that we only manipulate user pte bits when the pte
is marked present.
Signed-off-by: Will Deacon <will.dea...@arm.com>
Signed-off-by: Catalin Marinas <catalin.mari...@arm.com>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
arch/arm64/include/asm/pgtable.h | 16 +++++++++-------
1 file changed, 9 insertions(+), 7 deletions(-)
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -132,9 +132,8 @@ extern struct page *empty_zero_page;
#define pte_write(pte) (!(pte_val(pte) & PTE_RDONLY))
#define pte_exec(pte) (!(pte_val(pte) & PTE_UXN))
-#define pte_present_exec_user(pte) \
- ((pte_val(pte) & (PTE_VALID | PTE_USER | PTE_UXN)) == \
- (PTE_VALID | PTE_USER))
+#define pte_present_user(pte) \
+ ((pte_val(pte) & (PTE_VALID | PTE_USER)) == (PTE_VALID | PTE_USER))
#define PTE_BIT_FUNC(fn,op) \
static inline pte_t pte_##fn(pte_t pte) { pte_val(pte) op; return pte; }
@@ -157,10 +156,13 @@ extern void __sync_icache_dcache(pte_t p
static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
pte_t *ptep, pte_t pte)
{
- if (pte_present_exec_user(pte))
- __sync_icache_dcache(pte, addr);
- if (!pte_dirty(pte))
- pte = pte_wrprotect(pte);
+ if (pte_present_user(pte)) {
+ if (pte_exec(pte))
+ __sync_icache_dcache(pte, addr);
+ if (!pte_dirty(pte))
+ pte = pte_wrprotect(pte);
+ }
+
set_pte(ptep, pte);
}
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
