s390/kasan: support preemptible kernel build (cf3dbe5d) · Commits · 戴 / test

When the kernel is built with: CONFIG_PREEMPT=y CONFIG_PREEMPT_COUNT=y "stfle" function used by kasan initialization code makes additional call to preempt_count_add/preempt_count_sub. To avoid removing kasan instrumentation from sched code where those functions leave split stfle function and provide __stfle variant without preemption handling to be used by Kasan. Reported-by:

Benjamin Block <bblock@linux.ibm.com> Acked-by:

Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by:

Vasily Gorbik <gor@linux.ibm.com> Signed-off-by:

Martin Schwidefsky <schwidefsky@de.ibm.com>

arch/s390/include/asm/facility.h

+7 −2

Original line number	Diff line number	Diff line
		@@ -64,11 +64,10 @@ static inline int test_facility(unsigned long nr)
		* @stfle_fac_list: array where facility list can be stored
		* @size: size of passed in array in double words
		*/
		static inline void stfle(u64 *stfle_fac_list, int size)
		static inline void __stfle(u64 *stfle_fac_list, int size)
		{
		unsigned long nr;

		preempt_disable();
		asm volatile(
		" stfl 0(0)\n"
		: "=m" (S390_lowcore.stfl_fac_list));
		@@ -85,6 +84,12 @@ static inline void stfle(u64 *stfle_fac_list, int size)
		nr = (reg0 + 1) * 8; /* # bytes stored by stfle */
		}
		memset((char ) stfle_fac_list + nr, 0, size 8 - nr);
		}

		static inline void stfle(u64 *stfle_fac_list, int size)
		{
		preempt_disable();
		__stfle(stfle_fac_list, size);
		preempt_enable();
		}

arch/s390/mm/kasan_init.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -222,7 +222,7 @@ static void __init kasan_enable_dat(void)

		static void __init kasan_early_detect_facilities(void)
		{
		stfle(S390_lowcore.stfle_fac_list,
		__stfle(S390_lowcore.stfle_fac_list,
		ARRAY_SIZE(S390_lowcore.stfle_fac_list));
		if (test_facility(8)) {
		has_edat = true;

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