Are We Shooting Ourselves in the Foot with Stack Overflow?
Most traditional, beaten-path memory layouts allocate the stack space above the data sections in RAM, even though the stack grows “down” (towards the lower memory addresses) in most embedded processors. This arrangement puts your program data in the path of destruction of a stack overflow. In other words, you violate the first Gun Safety Rule (ALWAYS keep the gun pointed in a safe direction!) and you end up shooting yourself in the foot. This article shows how to locate the stack at the BEGINNING of RAM and thus point it in the "safe" direction.
Summary
This blog by Miro Samek explains why conventional RAM layouts place stacks in the path of data and how that increases the risk of catastrophic stack overflows. It shows how to relocate the stack to the beginning of RAM so it grows into unused space, with practical guidance for embedded firmware and RTOS projects.
Key Takeaways
- Understand how common linker-script memory layouts put program data in the path of a downward-growing stack.
- Learn how to modify linker scripts to place the stack at the start of RAM so it grows into safe space.
- Apply practical checks and map-analysis techniques to verify stack placement and identify overflow risks.
- Implement simple runtime and build-time protections (stack guards, canaries, map inspections) to reduce overflow impact.
- Integrate the approach into RTOS or bare-metal projects without breaking startup code or interrupts.
Who Should Read This
Embedded firmware engineers and systems programmers with experience writing linker scripts or configuring RTOS/boot code who want to reduce stack-overflow risk and hard-faults.
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