On Tue, Feb 23, 2010 at 08:30:46AM -0500, Steven Rostedt wrote:

On Sun, 2010-02-14 at 01:18 +0530, Rabin Vincent wrote:

quoted

On ARM, we have two ABIs, and the ABI used is controlled via a config
option.  Object files built with one ABI can't be merged with object
files built with the other ABI.  So, record_mcount.pl needs to use the
same compiler flags as the kernel when generating the object file with
the mcount locations.  Ensure this by passing CFLAGS to the script.

I'm fine with this for now, but I'm wondering if we should pass the
autoconf.h to the script and parse that instead. This would give us all
set config options that we can look at.

The correct ABI options are constructed using cc-option and friends, and
that logic would need to be duplicated in recordmcount.pl if we had to
parse autoconf.h.

I originally tried to add a new RECORDMCOUNT_CFLAGS variable in the ARM
Makefile and have that used here instead of KBUILD_CFLAGS (since
KBUILD_CFLAGS includes a whole bunch of possibly irrelevant options),
but coudn't figure out why my new variable wasn't accessible in
Makefile.build.

But I need to go back and start looking at converting recordmcount.pl to
recordmcount.c again.

quoted

Signed-off-by: Rabin Vincent <redacted>
---
 scripts/Makefile.build |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index 0b94d2f..2535c11 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build

@@ -209,7 +209,8 @@ ifdef CONFIG_FTRACE_MCOUNT_RECORD
 cmd_record_mcount = set -e ; perl $(srctree)/scripts/recordmcount.pl "$(ARCH)" \
 	"$(if $(CONFIG_CPU_BIG_ENDIAN),big,little)" \
 	"$(if $(CONFIG_64BIT),64,32)" \
-	"$(OBJDUMP)" "$(OBJCOPY)" "$(CC)" "$(LD)" "$(NM)" "$(RM)" "$(MV)" \
+	"$(OBJDUMP)" "$(OBJCOPY)" "$(CC) $(KBUILD_CFLAGS)" \
+	"$(LD)" "$(NM)" "$(RM)" "$(MV)" \

Doesn't this need to be with the change of recordmcount.pl too?
Otherwise applying this patch alone will break it. We need every step of
the patches to work otherwise we risk breaking a kernel bisect.

Dynamic ftrace for ARM is only enabled in the last patch of the series,
so this woudn't be breaking it.  No modification should be required for
record_mcount.pl for other archs because this doesn't add/remove any
parameters.

Rabin