Re: Memory protection between compilation units?

Il 12/06/2025 20:59, Kaz Kylheku ha scritto:

On 2025-06-12, Mateusz Viste <mateusz@x.invalid> wrote:

Thank you all for your thoughtful responses. You rightly identified
that the problem is essentially an out-of-bounds access - a symptom of
deeper code quality issues. The bug in question managed to pass unit
tests, peer review, functional tests, and it didn’t trigger any
warnings from GCC or clang, even with the strict -Weverything flag I
enforce across my teams. This underscores a fundamental truth: every
software has bugs, and some, like this one, are notoriously difficult
to locate. The bug caused a segfault about once every 10 days,
manifesting in an unrelated part of the code and sometimes days after
the out-of-bounds write occurred.
>
This led me to wonder how I could accelerate such crashes to simplify
debugging.

 Below is a proof-of-concept program that works in GNU/Linux.  For
rapidity of prototyping, I have assumed a page size of 4096; this is not
right for all systems.

[...]
However this strategy assumes you already know there's some instruction that write to the array at an out-of-bound position.
I think the situation of the original post is different. His program crashed infrequently, very infrequently, and he didn't know anything about the cause. I think it was a very big effort to link the crash to the array (in another source module) and to the out-of-bound access of the array.