Commit 079ef536 authored Jul 14, 2020 by Jiri Olsa Committed by Alexei Starovoitov Jul 14, 2020

bpf: Fix build for disabled CONFIG_DEBUG_INFO_BTF option

Stephen reported following linker warnings on powerpc build:

ld: warning: orphan section `.BTF_ids' from `kernel/trace/bpf_trace.o' being placed in section `.BTF_ids'
ld: warning: orphan section `.BTF_ids' from `kernel/bpf/btf.o' being placed in section `.BTF_ids'
ld: warning: orphan section `.BTF_ids' from `kernel/bpf/stackmap.o' being placed in section `.BTF_ids'
ld: warning: orphan section `.BTF_ids' from `net/core/filter.o' being placed in section `.BTF_ids'
ld: warning: orphan section `.BTF_ids' from `kernel/trace/bpf_trace.o' being placed in section `.BTF_ids'

It's because we generated .BTF_ids section even when
CONFIG_DEBUG_INFO_BTF is not enabled. Fixing this by
generating empty btf_id arrays for this case.

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/20200714102534.299280-1-jolsa@kernel.org

parent f7d40ee7

include/linux/btf_ids.h

+9 −0

Original line number	Diff line number	Diff line
		@@ -3,6 +3,8 @@
		#ifndef _LINUX_BTF_IDS_H
		#define _LINUX_BTF_IDS_H

		#ifdef CONFIG_DEBUG_INFO_BTF

		#include <linux/compiler.h> /* for __PASTE */

		/*
		@@ -83,5 +85,12 @@ asm( \
		".zero 4 \n" \
		".popsection; \n");

		#else

		#define BTF_ID_LIST(name) static u32 name[5];
		#define BTF_ID(prefix, name)
		#define BTF_ID_UNUSED

		#endif /* CONFIG_DEBUG_INFO_BTF */

		#endif

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