"Strong" stack protection for GCC

For example, in our DSP assembly kernel test benches, we actually went further than keeping a single canary word. We actually kept a sizeable buffer zone ahead of and behind the "live" data in the test bench, since some DSP algorithms write results separated by particular stride. (Think column accesses in a 2-D array for one common class.) I also wrote a "dmalloc" wrapper that put pad at both ends as well. Of course, that was all back in the 90s, when writing large amounts of assembly code for DSPs was much more commonplace.

But, as you said, it was more for catching programming errors than for preventing security exploits.