Kees, Kees Cook <keescook@xxxxxxxxxxxx> writes: > On Tue, Jul 21, 2020 at 12:57:16PM +0200, Thomas Gleixner wrote: > > This doesn't look very expensive, and they certain indicate really bad > conditions. Does this need to be behind a CONFIG? (Whatever the answer, > we can probably make those changes in a later series -- some of these > also look not arch-specific...) The most expensive part is native_save_flags(). The extra branches could be visible in benchmarks, but its a good question whether this should be just enabled. I just keep it as is for now as I would need to make the flags and the on_thread_stack() part x86 specific anyway, but yes we can revisit that once we agreed on the general direction of this. Thanks, tglx