Commit 11bb2f7a authored Jul 14, 2020 by Jiri Olsa Committed by Alexei Starovoitov Jul 14, 2020

bpf: Fix cross build for CONFIG_DEBUG_INFO_BTF option



Stephen and 0-DAY CI Kernel Test Service reported broken cross build
for arm (arm-linux-gnueabi-gcc (GCC) 9.3.0), with following output:

   /tmp/ccMS5uth.s: Assembler messages:
   /tmp/ccMS5uth.s:69: Error: unrecognized symbol type ""
   /tmp/ccMS5uth.s:82: Error: unrecognized symbol type ""

Having '@object' for .type  diretive is  wrong because '@' is comment
character for some architectures. Using STT_OBJECT instead that should
work everywhere.

Also using HOST* variables to build resolve_btfids so it's properly
build in crossbuilds (stolen from objtool's Makefile).

Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/bpf/20200714102534.299280-2-jolsa@kernel.org

parent 079ef536

include/linux/btf_ids.h

+1 −1

Original line number	Diff line number	Diff line
		@@ -23,7 +23,7 @@
		asm( \
		".pushsection " BTF_IDS_SECTION ",\"a\"; \n" \
		".local " #symbol " ; \n" \
		".type " #symbol ", @object; \n" \
		".type " #symbol ", STT_OBJECT; \n" \
		".size " #symbol ", 4; \n" \
		#symbol ": \n" \
		".zero 4 \n" \

tools/bpf/resolve_btfids/Makefile

+14 −0

Original line number	Diff line number	Diff line
		@@ -16,6 +16,20 @@ else
		MAKEFLAGS=--no-print-directory
		endif

		# always use the host compiler
		ifneq ($(LLVM),)
		HOSTAR ?= llvm-ar
		HOSTCC ?= clang
		HOSTLD ?= ld.lld
		else
		HOSTAR ?= ar
		HOSTCC ?= gcc
		HOSTLD ?= ld
		endif
		AR = $(HOSTAR)
		CC = $(HOSTCC)
		LD = $(HOSTLD)

		OUTPUT ?= $(srctree)/tools/bpf/resolve_btfids/

		LIBBPF_SRC := $(srctree)/tools/lib/bpf/

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