On 1/15/19 8:51 AM, stan wrote:
I compiled a custom fedora 5.0 kernel, and one of the new options was to have the kernel zero the stack on return from kernel functions. The cost was about 1% on a single cpu system. I made the judgement that this would be great on cloud servers, but wasn't really necessary for a local machine. Is there a reason it might be good for a local machine to have this enabled?
I'm guessing you're referring to CONFIG_GCC_PLUGIN_STACKLEAK. It really depends on what you want to prevent with this option. The goal is to prevent leaking of sensitive stack data (e.g. keys). You're right that cloud based servers would see more benefit but I could see you wanting this enabled on certain high value local machines. If there is a particular machine that you would _really_ rather not get compromised, it might be worth enabling. Also for the record, CONFIG_GCC_PLUGIN_STACKLEAK isn't on in Fedora officially because we don't currently enable any gcc plugins. It's something we might look into in the future though. Thanks, Laura _______________________________________________ kernel mailing list -- kernel@xxxxxxxxxxxxxxxxxxxxxxx To unsubscribe send an email to kernel-leave@xxxxxxxxxxxxxxxxxxxxxxx Fedora Code of Conduct: https://getfedora.org/code-of-conduct.html List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/kernel@xxxxxxxxxxxxxxxxxxxxxxx
