a3e63c44dd
Updated documentation to explain how to enable detection during context switching. Co-authored-by: Chengdong Wang <wangchengdong@lixiang.com> Signed-off-by: guoshengyuan1 <guoshengyuan1@xiaomi.com>
80 lines
2.7 KiB
ReStructuredText
80 lines
2.7 KiB
ReStructuredText
====================================
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Stack Overflow Check
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====================================
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Overview
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--------
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Currently NuttX supports three types of stack overflow detection:
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1. Stack Overflow Software Check During Function Call
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2. Stack Overflow Software Check During Context Switching
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3. Stack Overflow Hardware Check
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4. Stack Canary Check
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The software stack detection during function call includes two implementation ideas:
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1. Implemented by coloring the stack memory
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2. Implemented by comparing the sp and sl registers
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The software stack detection during context switching includes two implementation ideas:
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1. Implemented by coloring the stack memory
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2. Implemented by checking the bottom memory of the stack and the sp register
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Support
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-------
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Software and hardware stack overflow detection implementation,
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currently only implemented on ARM Cortex-M (32-bit) series chips
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Stack Canary Check is available on all platforms
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Stack Overflow Software Check During Function Call
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--------------------------------------------------
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1. Memory Coloring Implementation Principle
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1. Before using the stack, Thread will refresh the stack area to 0xdeadbeef
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2. When Thread is running, it will overwrite 0xdeadbeef
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3. up_check_tcbstack() detects 0xdeadbeef to get the stack peak value
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Usage:
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Enable CONFIG_STACK_COLORATION
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2. Compare sp and sl
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When compiling the program, keep r10 and use r10 as stackbase::
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'''
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ARCHOPTIMIZATION += -finstrument-functions -ffixed-r10
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Each function will automatically add the following when entering and exiting:
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__cyg_profile_func_enter
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__cyg_profile_func_exit
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Usage:
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Enable CONFIG_ARMV8M_STACKCHECK or CONFIG_ARMV7M_STACKCHECK
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Stack Overflow Software Check During Context Switching
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------------------------------------------------------
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1. Determine by detecting the number of bytes specified at the bottom of the stack.
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2. Check if the sp register is out of bounds.
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Usage:
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Enable CONFIG_STACKCHECK_SOFTWARE
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You can set the detection length by STACKCHECK_MARGIN
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Stack Overflow Hardware Check
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-----------------------------
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1. Set MSPLIM PSPLIM when context switching
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2. Each time sp is operated, the hardware automatically compares sp and PSPLIM. If sp is lower than PSPLIM, crash
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Usage:
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Enable CONFIG_ARMV8M_STACKCHECK_HARDWARE
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Stack Canary Check
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-----------------------------
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1. Add a canary value to the stack
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2. When the thread is running, the canary value is overwritten
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3. When the thread is running, the canary value is compared with the original value
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4. If the value is different, it means that the stack is overflowed
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Usage:
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Enable CONFIG_STACK_CANARIES
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