michaelh/zephyr
1
0
Fork 0
Code Releases Activity

arm: core: mpu: Prevent updating unexpected region

Browse source 
The REGION bits (bit[3:0]) of MPU_RBAR register can specify the number
of the region to update if the VALID bit (bit[4]) is also set.

If the bit[3:0] of "region_addr" are not zero, might cause to update
unexpected region. This could happen since we might not declare stack
memory with specific alignment.

This patch will mask the bit[4:0] of "region_addr" to prevent updating
unexpected region.

Signed-off-by: Chunlin Han <chunlin.han@linaro.org>
This commit is contained in:
chunlin 2017-05-25 19:06:20 +08:00 • committed by Kumar Gala
commit e125e5b9c6
2 changed files with 5 additions and 1 deletions
Download patch file Download diff file Expand all files Collapse all files

3
arch/arm/core/cortex_m/mpu/arm_mpu.c
View file

@ -64,7 +64,8 @@ static void _region_init(u32_t index, u32_t region_addr,
/* Select the region you want to access */ /* Select the region you want to access */
ARM_MPU_DEV->rnr = index; ARM_MPU_DEV->rnr = index;
/* Configure the region */ /* Configure the region */
ARM_MPU_DEV->rbar = region_addr | REGION_VALID | index; ARM_MPU_DEV->rbar = (region_addr & REGION_BASE_ADDR_MASK)
| REGION_VALID | index;
ARM_MPU_DEV->rasr = region_attr | REGION_ENABLE; ARM_MPU_DEV->rasr = region_attr | REGION_ENABLE;
} }

3
include/arch/arm/cortex_m/mpu/arm_mpu.h
View file

@ -44,6 +44,9 @@ struct arm_mpu {
#define ARM_MPU_PRIVDEFENA (1 << 2) #define ARM_MPU_PRIVDEFENA (1 << 2)
#define REGION_VALID (1 << 4) #define REGION_VALID (1 << 4)
/* ARM MPU RBAR Register */
/* Region base address mask */
#define REGION_BASE_ADDR_MASK 0xFFFFFFE0
/* eXecute Never */ /* eXecute Never */
#define NOT_EXEC (0x1 << 28) #define NOT_EXEC (0x1 << 28)