On Thu, Jul 14, 2022 at 11:01:12AM +0200, Greg Kroah-Hartman wrote:
On Thu, Jul 14, 2022 at 02:15:07PM +0530, Naresh Kamboju wrote:
We are booting the i386 kernel on an x86 machine. With Spectre V2 patches merged into Linux mainline we have been noticing RETBleed: WARNING: Spectre v2 mitigation leaves CPU vulnerable to RETBleed attacks, data leaks possible!
That's funny. I don't think that's a valid combination that should be cared about, but I'll leave it to Pawan to comment if it is something that is "real" to be concerned for.
Alas, some people still run that because of not knowing any better. Until not so long ago, they were proposed with two install media, "32-bit" and "64-bit", but no explanation. Upgrades keep working, crossgrades are still only for the brave of the heart, and reinstalling might not appear to have a reason compelling enough. And for quite some tasks, halved word size (thus ~2/3 memory usage) can overcome register starvation and win benchmarks.
Thus I wonder: perhaps such combinations we consider to be invalid should refuse to boot unless given a cmdline parameter?
Meow!