AM62L: Some Security Question For ASLR/DEP/Stack Protection

Hello, 

Any comment?

Thank You Very Much

Gibbs

Hi Gibbs,

The methods listed in your post are the general techniques to harden the security system design, but not TI Linux SDK specifics. I’d recommend the customer explore and investigate the various approaches as listed and beyond themself based upon their security requirements.

Best,

-Hong

Hi Hong, 

This is WNC SW Jerry.

From our understanding for stack protection, stack protection is typically enabled via compiler options (e.g. -fstack-protector-strong) and supported by GCC. Since the AM62L SDK uses GCC 9.x, this feature should be available from a toolchain perspective.

To ensure correct implementation, could you please help confirm:

1. Whether there are any recommended compiler flags or TI SDK configurations to enable stack protection?
2. Whether there are any TI reference configurations or best practices for enabling stack protection in AM62L Linux SDK?
3. If there are any known limitations or considerations (e.g. performance impact, compatibility issues) when enabling stack protection on this platform?

This will help us ensure proper implementation and alignment with our security requirements.

Thanks

BR
Jerry

Hello Jerry 

Hong is out of office today, so please expect a response tomorrow or day after. 

Regards

Mukul 

Thanks Hong & Mukul

Jerry is my customer.

Share some knowledge what I know (search) about your question before Hong returns

About Q1/Q2.

It is trade off between performance & security requriments, there is no standard answer.

Here are some usage scenario.

1. Stack Canaries (Buffer Overflow Protection)
- Enabled with -fstack-protector flags
- Options:
- -fstack-protector: Protects functions with local arrays or calls
- -fstack-protector-all: Protects all functions
- -fstack-protector-strong: Protects more functions than default (recommended)
- -fstack-protector-explicit: Only protects functions with __attribute__((stack_protect_all))

2. Stack Clash Protection
- -fstack-clash-protection: Prevents stack clash attacks by probing stack pages

3. Return-Oriented Programming (ROP) Protection
- -fcf-protection: Control flow integrity (requires CPU support, Intel CET/ARM BTI)

Example Usage

# Compile with stack protection
gcc -fstack-protector-strong -o myprogram myprogram.c

# Compile with all protections
gcc -fstack-protector-all -fstack-clash-protection -o myprogram myprogram.c

# Check if binary was compiled with protections
readelf -l myprogram | grep STACK

so you can combine many build flags to support stack protection.

About Q3 : 

Performance Overhead

- Canary insertion/checking adds CPU cycles on function entry/exit
- Can be 1-3% overhead for typical applications
- Higher overhead in functions with many stack variables
- Critical for performance-sensitive code (real-time systems, tight loops)

Memory Overhead

- Each function adds canary storage on stack (typically 8 bytes)
- Accumulates in deep call stacks
- Problematic for embedded systems with limited RAM

When you enable stack protection, it may be reduce a little bit "real time performance" your application code. 

But base on your application, it think you may not have much concern about real time.

Many Thanks

Gibbs 

Hi Jerry,
"CONFIG_STACKPROTECTOR_STRONG=y" is currently configured in the kernel ".config" file in AM62Lx Linux SDK.
It is user's choice to select & re-configure the stack protection option to mitigate against stack buffer overflow attacks as necessary per user's security requirements.
Best,
-Hong