On Mon, Jul 27, 2020 at 10:56:03PM +0200, Thomas Gleixner wrote: > pet...@infradead.org writes: > > Abuse the SMAP rules to ensure poke_int3_handler() doesn't call out to > > anything. > > Yuck. Isn't that what noinstr is for or am I missing something?
Well, we don't want poke_int3_handler() to call out to noinstr either. So noinstr only allows calling noinstr, The above hack only allows it calling uaccess-safe functions, and the group of functions that is both noinstr and uaccess-safe is 'small'. But like I said yesterday, perhaps this wants it own annotation. Then we can also verify the lack of any dynamic code. So yes, yuck and a bad idea, ignore this ;-)