From 07fd7d4bbcb9a7c741c7e67e715680d9e5835ff2 Mon Sep 17 00:00:00 2001 From: Vineet Gupta Date: Mon, 21 Dec 2015 12:38:01 +0530 Subject: [PATCH] ARC: Fix linking errors with CONFIG_MODULE + CONFIG_CC_OPTIMIZE_FOR_SIZE At -Os, ARC gcc generates millicode thunk for function prologue/epilogue, which are served by libgcc. Modules historically are NOT linked with libgcc to avoid code bloat, reducing runtime relocation fixups etc. I even once tried doing that but got lost in makefile intricacies. This means modules at -Os don't get the millicode thunks, causing build failures below: | MODPOST 5 modules | ERROR: "__ld_r13_to_r18" [crypto/sha256_generic.ko] undefined! | ERROR: "__ld_r13_to_r18_ret" [crypto/sha256_generic.ko] undefined! | ERROR: "__st_r13_to_r18" [crypto/sha256_generic.ko] undefined! | ERROR: "__ld_r13_to_r17_ret" [crypto/sha256_generic.ko] undefined! | ERROR: "__st_r13_to_r17" [crypto/sha256_generic.ko] undefined! | ERROR: "__ld_r13_to_r16_ret" [crypto/sha256_generic.ko] undefined! | ERROR: "__st_r13_to_r16" [crypto/sha256_generic.ko] undefined! |.... |.... Workaround that by inhibiting millicode thunks for loadable modules Fixes STAR 9000641864: ("Linux built with optimizations for size emits errors for modules") Reported-by: Anton Kolesov Cc: Michal Marek Cc: linux-kernel@vger.kernel.org Signed-off-by: Vineet Gupta --- arch/arc/Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/arc/Makefile b/arch/arc/Makefile index cf0cf34eeb24..aeb19021099e 100644 --- a/arch/arc/Makefile +++ b/arch/arc/Makefile @@ -81,7 +81,7 @@ endif LIBGCC := $(shell $(CC) $(cflags-y) --print-libgcc-file-name) # Modules with short calls might break for calls into builtin-kernel -KBUILD_CFLAGS_MODULE += -mlong-calls +KBUILD_CFLAGS_MODULE += -mlong-calls -mno-millicode # Finally dump eveything into kernel build system KBUILD_CFLAGS += $(cflags-y) -- 2.20.1