From: Jiri Olsa <jolsa@kernel.org>
Date: Tue, 14 Jul 2020 12:25:34 +0200
Subject: bpf: Fix cross build for CONFIG_DEBUG_INFO_BTF option
Patch-mainline: v5.9-rc1
Git-commit: 11bb2f7a45909f4f64afe471875672ae1b84a380
References: bsc#1177028
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
Acked-by: Gary Lin <glin@suse.com>
---
include/linux/btf_ids.h | 2 +-
tools/bpf/resolve_btfids/Makefile | 14 ++++++++++++++
2 files changed, 15 insertions(+), 1 deletion(-)
--- a/include/linux/btf_ids.h
+++ b/include/linux/btf_ids.h
@@ -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" \
--- a/tools/bpf/resolve_btfids/Makefile
+++ b/tools/bpf/resolve_btfids/Makefile
@@ -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/