This reverts commit
c8fdd247255a3a027cd9f66dcf93e6847d1d2f85.
It turns out the kernel was correct, and the gcc complaint was a gcc
bug. The preferred stack boundary is expressed not in bytes, but in the
the log2() of the preferred boundary, so "-mpreferred-stack-boundary=2"
is in fact exactly what we want, but a gcc that is compiled for x86-64
will consider it an error (because the 64-bit calling sequence says that
the stack should be 16-byte aligned) even if we are then using "-m32" to
generate 32-bit code.
Noted-by: Mikulas Patocka <mikulas@artax.karlin.mff.cuni.cz>
Cc: Jan Hubicka <jh@suse.cz>
Acked-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
include $(srctree)/arch/$(ARCH)/Makefile
ifdef CONFIG_FRAME_POINTER
-CFLAGS += -fno-omit-frame-pointer -fno-optimize-sibling-calls
+CFLAGS += -fno-omit-frame-pointer $(call cc-option,-fno-optimize-sibling-calls,)
else
CFLAGS += -fomit-frame-pointer
endif
CFLAGS += -pipe -msoft-float -mregparm=3 -freg-struct-return
# prevent gcc from keeping the stack 16 byte aligned
-CFLAGS += -mpreferred-stack-boundary=4
+CFLAGS += $(call cc-option,-mpreferred-stack-boundary=2)
# CPU-specific tuning. Anything which can be shared with UML should go here.
include $(srctree)/arch/i386/Makefile.cpu