Linux 5.10 To See Static Calls For Helping Cases Where Retpolines Are Used

[phoronix]

Phoronix: Linux 5.10 To See Static Calls For Helping Cases Where Retpolines Are Used

A new kernel feature sent in today for the Linux 5.10 merge window is static calls, which can be helpful in cases where Retpolines (return trampolines) are currently used as part of protections against speculative execution vulnerabilities like Spectre...

http://www.phoronix.com/scan.php?page=news_item&px=Linux-5.10-Static-Calls

[ed31337]

So, in other words, now we're optimizing the kernel by using self modifying code? Awesome!

[linuxgeex]

So, in other words, now we're optimizing the kernel by using self modifying code? Awesome!

The kernel has been using self-modifying code for optimisation and feature enablement for a long time. SMP enablement is one example.

[baryluk]

So, in other words, now we're optimizing the kernel by using self modifying code? Awesome!

There is already a lot of self modifying code in kernel, one of more famous ones being ftrace.

I am really surprised they didn't use this self modifying code approach first when they were implementing meltdown fixes and such. I guess they were on a tight schedule, and didn't want to mess things up.