Commit 7e9501fd authored by Rabin Vincent's avatar Rabin Vincent Committed by Russell King

ARM: 6312/1: ftrace: allow building without frame pointers

With current gcc, compiling with both -pg and -fomit-frame-pointer is
not allowed.  However, -pg can be used to build without actually
specifying -fno-omit-frame-pointer, upon which the default behaviour
for the target will be used.

On ARM, it is not possible to build a Thumb-2 kernel with
-fno-omit-frame-pointer (FRAME_POINTERS depends on !THUMB2_KERNEL). In
order to support ftrace for Thumb-2, we need to be able to allow a
combination of FUNCTION_TRACER and !FRAME_POINTER.  We do this by
omitting -fomit-frame-pointer if ftrace is enabled.
Acked-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: default avatarRabin Vincent <rabin@rab.in>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent d4348c67
......@@ -554,8 +554,15 @@ endif
ifdef CONFIG_FRAME_POINTER
KBUILD_CFLAGS += -fno-omit-frame-pointer -fno-optimize-sibling-calls
else
# Some targets (ARM with Thumb2, for example), can't be built with frame
# pointers. For those, we don't have FUNCTION_TRACER automatically
# select FRAME_POINTER. However, FUNCTION_TRACER adds -pg, and this is
# incompatible with -fomit-frame-pointer with current GCC, so we don't use
# -fomit-frame-pointer with FUNCTION_TRACER.
ifndef CONFIG_FUNCTION_TRACER
KBUILD_CFLAGS += -fomit-frame-pointer
endif
endif
ifdef CONFIG_DEBUG_INFO
KBUILD_CFLAGS += -g
......
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