Commit ba96301c authored Mar 05, 2020 by Naveen N. Rao Committed by Michael Ellerman Apr 01, 2020

powerpc: Suppress .eh_frame generation

GCC v8 defaults to enabling -fasynchronous-unwind-tables due to
https://gcc.gnu.org/r259298

, which results in .eh_frame section being
generated. This results in additional disk usage by the build, as well
as the kernel modules. Since the kernel has no use for this, this
section is discarded.

Add -fno-asynchronous-unwind-tables to KBUILD_CFLAGS to suppress
generation of .eh_frame section. Note that our VDSOs need .eh_frame, but
are not affected by this change since our VDSO code are all in assembly.

Reported-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Reviewed-by: Segher Boessenkool <segher@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1ed7cd84a7d1a3180b30c0c60e70eed8bb8b40c3.1583415544.git.naveen.n.rao@linux.vnet.ibm.com

parent c04868df

arch/powerpc/Makefile

+3 −0

Original line number	Diff line number	Diff line
		@@ -239,6 +239,9 @@ KBUILD_CFLAGS += $(call cc-option,-mno-vsx)
		KBUILD_CFLAGS += $(call cc-option,-mno-spe)
		KBUILD_CFLAGS += $(call cc-option,-mspe=no)

		# Don't emit .eh_frame since we have no use for it
		KBUILD_CFLAGS += -fno-asynchronous-unwind-tables

		# Never use string load/store instructions as they are
		# often slow when they are implemented at all
		KBUILD_CFLAGS += $(call cc-option,-mno-string)

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