ARM: 8235/1: Support for the PXN CPU feature on ARMv7

Modern ARMv7-A/R cores optionally implement below new
hardware feature:

- PXN:
Privileged execute-never(PXN) is a security feature. PXN bit
determines whether the processor can execute software from
the region. This is effective solution against ret2usr attack.
On an implementation that does not include the LPAE, PXN is
optionally supported.

This patch set PXN bit on user page table for preventing
user code execution with privilege mode.

Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Jungseung Lee <js07.lee@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This commit is contained in:
Jungseung Lee
2014-11-29 02:33:30 +01:00
committed by Russell King
parent 44cb09c23f
commit 1d4d37159d
4 changed files with 29 additions and 2 deletions

View File

@@ -76,6 +76,7 @@
#define PTE_EXT_SHARED (_AT(pteval_t, 3) << 8) /* SH[1:0], inner shareable */
#define PTE_EXT_AF (_AT(pteval_t, 1) << 10) /* Access Flag */
#define PTE_EXT_NG (_AT(pteval_t, 1) << 11) /* nG */
#define PTE_EXT_PXN (_AT(pteval_t, 1) << 53) /* PXN */
#define PTE_EXT_XN (_AT(pteval_t, 1) << 54) /* XN */
/*