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dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=JOtPhia4; spf=none (imf14.hostedemail.com: domain of peterz@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=peterz@infradead.org; dmarc=none X-Stat-Signature: b3xbmnk64e38x46kb885toc9z3h3wpqr X-Rspam-User: X-Rspamd-Server: rspam11 X-Rspamd-Queue-Id: 1E864100011 X-HE-Tag: 1667393582-809032 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: 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 > Cc: Dmitry Vyukov > Cc: Marco Elver > Cc: Peter Zijlstra (Intel) > Link: https://lore.kernel.org/lkml/20221025221755.3810809-1-glider@google.com/ > Signed-off-by: Alexander Potapenko Acked-by: Peter Zijlstra (Intel) > --- > 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 >