On Mon, 19 Jun 2017, Jeff Law wrote: > A key point to remember is that you can never have an allocation > (potentially using more than one allocation site) which is larger than a > page without probing the page.
There's a platform ABI issue here. At least some kernel fixes for these stack issues, as I understand it, increase the size of the stack guard to more than a single page. It would be possible to define the ABI to require such a larger guard for protection and so reduce the number of (non-alloca/VLA-using) functions that need probes generated, depending on whether a goal is to achieve security on kernels without such a fix. (Thinking in terms of how to get to enabling such probes by default.) -- Joseph S. Myers jos...@codesourcery.com
