When x86 CPU Stacks Overflow, They Will Now Be More Pronounced With Linux 5.2+

While the x86 IRQ changes to the Linux kernel during the merge window periods don't tend to be too interesting for end-users, there is a pleasant change introduced with the Linux 5.2 kernel.

Beginning with Linux 5.2, should your system(s) encounter any low-level stack overflows on x86-based processors, they should now be more "clear-cut faults/crashes" as opposed to experiencing silent memory corruption and sporadic failures. This is more useful to those that may be more ambitiously testing the Linux Git code but at least now if anything goes awry, it will be much quicker to spot problems as opposed to potentially odd behavior creeping in with time.

This change in behavior is coming due to adding x86-64 IRQ/exception/debug stack guard pages in order to detect stack overflows right away. In the process, a lot of code was cleaned up too in the x86/irq space.

More details via the x86/irq PR.