Build with -fno-dwarf2-cfi-asm

With a sufficiently new compiler and binutils, code which wasn't
previously generating .eh_frame sections has begun to.  Certain
architectures (powerpc, in this case) may generate unexpected relocation
formats in response to this, preventing modules from loading.

While the new relocation types should probably be handled, revert to the
previous behaviour with regards to generation of .eh_frame sections.

(This was reported against Fedora, which appears to be the only distro
doing any building against gcc-4.4 at present: RH bz#486545.)

Signed-off-by: Kyle McMartin <kyle@redhat.com>
Acked-by: Roland McGrath <roland@redhat.com>
Cc: Alexandre Oliva <aoliva@redhat.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Makefile

@@ -569,6 +569,9 @@ KBUILD_CFLAGS += $(call cc-option,-Wno-pointer-sign,)
 # disable invalid "can't wrap" optimzations for signed / pointers
 KBUILD_CFLAGS	+= $(call cc-option,-fwrapv)
 
+# revert to pre-gcc-4.4 behaviour of .eh_frame
+KBUILD_CFLAGS	+= $(call cc-option,-fno-dwarf2-cfi-asm)
+
 # Add user supplied CPPFLAGS, AFLAGS and CFLAGS as the last assignments
 # But warn user when we do so
 warn-assign = \