kmsan: make sure PREEMPT_RT is off

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.

Alexander Potapenko committed 4 years ago

Commit 83d0edf1 parent ac669981 file · +1 −0Browse files

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lib/Kconfig.kmsan+1−0

@@ -12,6 +12,7 @@ config KMSAN · 11 unmodified lines
12	bool "KMSAN: detector of uninitialized values use"	12	bool "KMSAN: detector of uninitialized values use"
13	depends on HAVE_ARCH_KMSAN && HAVE_KMSAN_COMPILER	13	depends on HAVE_ARCH_KMSAN && HAVE_KMSAN_COMPILER
14	depends on SLUB && DEBUG_KERNEL && !KASAN && !KCSAN	14	depends on SLUB && DEBUG_KERNEL && !KASAN && !KCSAN
		15	depends on !PREEMPT_RT
15	select STACKDEPOT	16	select STACKDEPOT
16	select STACKDEPOT_ALWAYS_INIT	17	select STACKDEPOT_ALWAYS_INIT
17	help	18	help