On Wed, Nov 02, 2022 at 12:06:10PM +0100, Alexander Potapenko wrote: > As pointed out by Peter Zijlstra, __msan_poison_alloca() does not play > well with IRQ code when PREEMPT_RT is on, because in that mode even > GFP_ATOMIC allocations cannot be performed. > > Fixing this would require making stackdepot completely lockless, which > is quite challenging and may be excessive for the time being. > > Instead, make sure KMSAN is incompatible with PREEMPT_RT, like other > debug configs are. > > Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> > Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx> > Cc: Marco Elver <elver@xxxxxxxxxx> > Cc: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx> > Link: https://lore.kernel.org/lkml/20221025221755.3810809-1-glider@xxxxxxxxxx/ > Signed-off-by: Alexander Potapenko <glider@xxxxxxxxxx> Acked-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx> > --- > lib/Kconfig.kmsan | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/lib/Kconfig.kmsan b/lib/Kconfig.kmsan > index b2489dd6503fa..ef2c8f256c57d 100644 > --- a/lib/Kconfig.kmsan > +++ b/lib/Kconfig.kmsan > @@ -12,6 +12,7 @@ config KMSAN > bool "KMSAN: detector of uninitialized values use" > depends on HAVE_ARCH_KMSAN && HAVE_KMSAN_COMPILER > depends on SLUB && DEBUG_KERNEL && !KASAN && !KCSAN > + depends on !PREEMPT_RT > select STACKDEPOT > select STACKDEPOT_ALWAYS_INIT > help > -- > 2.38.1.273.g43a17bfeac-goog >
