On Mon, Nov 19, 2012 at 03:59:33PM +0100, Vincent Stehlé wrote:
Separate the MMU identity mapping for ARM in a weak function, to allow redefinition with platform specific function.
This is motivated by the need to unmap the region near address zero on HS OMAP devices, to avoid speculative accesses. Accessing this region causes security violations, which we want to avoid.
Signed-off-by: Vincent Stehlé v-stehle@ti.com
arch/arm/lib/cache-cp15.c | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-)
diff --git a/arch/arm/lib/cache-cp15.c b/arch/arm/lib/cache-cp15.c index 939de10..886fe5c 100644 --- a/arch/arm/lib/cache-cp15.c +++ b/arch/arm/lib/cache-cp15.c @@ -40,6 +40,17 @@ void __arm_init_before_mmu(void) void arm_init_before_mmu(void) __attribute__((weak, alias("__arm_init_before_mmu")));
+void __arm_setup_identity_mapping(u32 *page_table) +{
- int i;
- /* Set up an identity-mapping for all 4GB, rw for everyone */
- for (i = 0; i < 4096; i++)
page_table[i] = i << 20 | (3 << 10) | 0x12;+} +void arm_setup_identity_mapping(u32 *page_table)
- __attribute__((weak, alias("__arm_setup_identity_mapping")));
Please use __weak as found in <linux/compiler.h>, thanks.