s390/kasan: double the stack size

Kasan stack instrumentation pads stack variables with redzones, which
increases stack frames size significantly. Stack sizes are increased
from 16k to 32k in the code, as well as for the kernel stack overflow
detection option (CHECK_STACK).

Reviewed-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

diff --git a/arch/s390/Makefile b/arch/s390/Makefile
index ee65185..0b33577 100644 (file)
--- a/arch/s390/Makefile
+++ b/arch/s390/Makefile
@@ -27,7 +27,7 @@ KBUILD_CFLAGS_DECOMPRESSOR += $(call cc-option,-ffreestanding)
 KBUILD_CFLAGS_DECOMPRESSOR += $(if $(CONFIG_DEBUG_INFO),-g)
 KBUILD_CFLAGS_DECOMPRESSOR += $(if $(CONFIG_DEBUG_INFO_DWARF4), $(call cc-option, -gdwarf-4,))
 UTS_MACHINE    := s390x
-STACK_SIZE     := 16384
+STACK_SIZE     := $(if $(CONFIG_KASAN),32768,16384)
 CHECKFLAGS     += -D__s390__ -D__s390x__
 
 export LD_BFD

diff --git a/arch/s390/include/asm/thread_info.h b/arch/s390/include/asm/thread_info.h
index 1bbbaf6..79b4060 100644 (file)
--- a/arch/s390/include/asm/thread_info.h
+++ b/arch/s390/include/asm/thread_info.h
@@ -13,7 +13,11 @@
 /*
  * General size of kernel stacks
  */
+#ifdef CONFIG_KASAN
+#define THREAD_SIZE_ORDER 3
+#else
 #define THREAD_SIZE_ORDER 2
+#endif
 #define THREAD_SIZE (PAGE_SIZE << THREAD_SIZE_ORDER)
 
 #ifndef __ASSEMBLY__