arm64: Add stack guard for v8r #62902
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Accessing mem before mmu or mpu init will cause a cache coherence issue. To avoid such a problem, move the safe exception stack init function after the mmu or mpu is initiated. Also change the data section attribute from INNER_SHAREABLE to OUTER_SHAREABLE. Otherwise there will be a cache coherence issue during the memory regions switch. Because we are using background region to do the regions switch, and the default background region is OUTER_SHAREABLE, if we use INNER_SHAREABLE as the foreground region, then we have to flush all cache regions to make sure the cached values are right. However, flushing all regions is too heavy, so we set OUTER_SHAREABLE to fix this issue. Signed-off-by: Jaxson Han <jaxson.han@arm.com>
Clean the thread->arch during the arch_new_thread to avoid unexpected behavior. If the thread struct is allocated from heap or in stack, the data in thread->arch might be dirty. Signed-off-by: Jaxson Han <jaxson.han@arm.com>
Introduce the ARM64_STACK_PROTECTION config. This option leverages the MMU or MPU to cause a system fatal error if the bounds of the current process stack are overflowed. This is done by preceding all stack areas with a fixed guard region. The config depends on MPU for now since MMU stack protection is not ready. Signed-off-by: Jaxson Han <jaxson.han@arm.com>
Add the stack check function z_arm64_stack_corruption_check at z_arm64_fatal_error to handle the stack overflow triggered by the hardware region. Signed-off-by: Jaxson Han <jaxson.han@arm.com>
Refactor the stack relevant macros to prepare to introduce the stack guard. Also add comments about the changes related to stack layout. Signed-off-by: Jaxson Han <jaxson.han@arm.com>
To make the stack guard works well, clean and refine the MPU code. To save the MPU regions (the number of MPU regions are limited), we choose to remove the guard region. Comparing to add an individual region to guard the stack, removing the guard region can at least save 2 regions per core. Similarly with userspace, the stack guard will leverage the dynamic regions switching mechanism which means we need a region switch during the context switch. Otherwise, the other option is using stack guard region, but this is very limited since the number of MPU regions is limited. Signed-off-by: Jaxson Han <jaxson.han@arm.com>
Enable stack guard for v8R which is backed by MPU. Signed-off-by: Jaxson Han <jaxson.han@arm.com>
The test case allocate struct k_thread thread in the stack. This will lead the random initial value of thread and thus cause the test cases randomly hang. To fix such issue, move the declartion of struct k_thread thread outside the function as a stacic variable. Signed-off-by: Jaxson Han <jaxson.han@arm.com>
The heap size is not enough so that it will cause the testcase fail. Increase to 32k to make sure it works for a long time in the future. Signed-off-by: Jaxson Han <jaxson.han@arm.com>
The stack guard report this testcase has the stack overflow issue. To fix the issue, slightly increse the stack size. Signed-off-by: Jaxson Han <jaxson.han@arm.com>
The test_sem_take_timeout_isr depends on the thread's priority. But for SMP platforms, the priority is different with no-SMP. High-priority threads and low-priority threads might run simultaneously at different cores. Set the test case run at 1cpu to fix such an issue. Signed-off-by: Jaxson Han <jaxson.han@arm.com>
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dcpleung,
andyross,
nashif,
cfriedt and
carlocaione
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zephyrbot
added
area: POSIX
carlocaione
approved these changes
Sep 21, 2023
SgrrZhf
approved these changes
Sep 21, 2023
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Add stack guard as an implementation of HW_STACK_PROTECTION. The original work is #55207, but the PR cannot be reopened, it might be too long, so I have to reopen a new one.
fvp_baser_aemv8randfvp_baser_aemv8r_smpboard with HW_STACK_PROTECTION enabled.samples/arch/smp/pi/Example:
or
The output will be something like:
Limitation:
printkor LOG