[PATCH] lockdep: s390 CONFIG_FRAME_POINTER support

CONFIG_FRAME_POINTER support for s390.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

2 files changed, 6 insertions, 1 deletions

diff --git a/arch/s390/Makefile b/arch/s390/Makefile
index b3791fb094a8..74ef57dcfa60 100644
--- a/arch/s390/Makefile
+++ b/arch/s390/Makefile
@@ -34,6 +34,11 @@ cflags-$(CONFIG_MARCH_G5)   += $(call cc-option,-march=g5)
 cflags-$(CONFIG_MARCH_Z900) += $(call cc-option,-march=z900)
 cflags-$(CONFIG_MARCH_Z990) += $(call cc-option,-march=z990)
 
+#
+# Prevent tail-call optimizations, to get clearer backtraces:
+#
+cflags-$(CONFIG_FRAME_POINTER) += -fno-optimize-sibling-calls
+
 # old style option for packed stacks
 ifeq ($(call cc-option-yn,-mkernel-backchain),y)
 cflags-$(CONFIG_PACK_STACK)  += -mkernel-backchain -D__PACK_STACK
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 04e374c6fd46..91e338a3d069 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -208,7 +208,7 @@ config DEBUG_VM
 
 config FRAME_POINTER
         bool "Compile the kernel with frame pointers"
-        depends on DEBUG_KERNEL && (X86 || CRIS || M68K || M68KNOMMU || FRV || UML)
+        depends on DEBUG_KERNEL && (X86 || CRIS || M68K || M68KNOMMU || FRV || UML || S390)
         default y if DEBUG_INFO && UML
         help
           If you say Y here the resulting kernel image will be slightly larger