On Wed, Nov 02, 2022 at 12:06:11PM +0100, Alexander Potapenko wrote: > There is a case in exc_invalid_op handler that is executed outside the > irqentry_enter()/irqentry_exit() region when an UD2 instruction is used > to encode a call to __warn(). > > In that case the `struct pt_regs` passed to the interrupt handler is > never unpoisoned by KMSAN (this is normally done in irqentry_enter()), > which leads to false positives inside handle_bug(). > > Use kmsan_unpoison_entry_regs() to explicitly unpoison those registers > before using them. As does poke_int3_handler(); does that need fixing up too? OTOH look *very very* carefully at the contraints there.
