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authorVasily Gorbik <gor@linux.ibm.com>2018-10-19 13:13:58 +0300
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2018-10-22 09:37:45 +0300
commitcf3dbe5dacb3a95d497ace9c714306d17cb05b11 (patch)
tree0b4bb870e5d7c0c09e1a7e8fb797f08530745297
parent63c19be095d0f8eb8992674991e44b4228bd4179 (diff)
downloadlinux-cf3dbe5dacb3a95d497ace9c714306d17cb05b11.tar.xz
s390/kasan: support preemptible kernel build
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>
-rw-r--r--arch/s390/include/asm/facility.h9
-rw-r--r--arch/s390/mm/kasan_init.c4
2 files changed, 9 insertions, 4 deletions
diff --git a/arch/s390/include/asm/facility.h b/arch/s390/include/asm/facility.h
index 99c8ce30b3cd..e78cda94456b 100644
--- a/arch/s390/include/asm/facility.h
+++ b/arch/s390/include/asm/facility.h
@@ -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();
}
diff --git a/arch/s390/mm/kasan_init.c b/arch/s390/mm/kasan_init.c
index 55982142b2b5..acb9645b762b 100644
--- a/arch/s390/mm/kasan_init.c
+++ b/arch/s390/mm/kasan_init.c
@@ -222,8 +222,8 @@ static void __init kasan_enable_dat(void)
static void __init kasan_early_detect_facilities(void)
{
- stfle(S390_lowcore.stfle_fac_list,
- ARRAY_SIZE(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;
__ctl_set_bit(0, 23);