Re: [PATCH v2 2/3] perf build: Remove libbpf pre-1.0 feature tests

From: Arnaldo Carvalho de Melo
Date: Mon Mar 13 2023 - 17:11:28 EST


Em Sun, Jan 15, 2023 at 05:01:14PM -0800, Ian Rogers escreveu:
> The feature tests were necessary for libbpf pre-1.0, but as the libbpf
> implies at least 1.0 we can remove these now.

So I added this:

diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
index 8b0bd3aa018ef166..b715cd4f43f4a014 100644
--- a/tools/perf/Makefile.config
+++ b/tools/perf/Makefile.config
@@ -580,7 +580,7 @@ ifndef NO_LIBELF
EXTLIBS += -lbpf
$(call detected,CONFIG_LIBBPF_DYNAMIC)
else
- dummy := $(error Error: No libbpf devel library found, please install libbpf-devel);
+ dummy := $(error Error: No libbpf devel library found or older than v1.0, please install/update libbpf-devel);
endif
else
# Libbpf will be built as a static library from tools/lib/bpf.

To better reflect the failure reason:

⬢[acme@toolbox perf-tools-next]$ cat /tmp/build/perf-tools-next/feature/test-libbpf.make.output
test-libbpf.c:5:2: error: #error At least libbpf 1.0 is required for Linux tools.
5 | #error At least libbpf 1.0 is required for Linux tools.
| ^~~~~
⬢[acme@toolbox perf-tools-next]$ rpm -q libbpf-devel
libbpf-devel-0.8.0-2.fc37.x86_64
⬢[acme@toolbox perf-tools-next]$

I'll see if I can make the build test conditional on libbpf being >= 1.0

- Arnaldo

> Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
> ---
> tools/build/feature/Makefile | 7 ---
> .../feature/test-libbpf-bpf_map_create.c | 8 ----
> .../test-libbpf-bpf_object__next_map.c | 8 ----
> .../test-libbpf-bpf_object__next_program.c | 8 ----
> .../build/feature/test-libbpf-bpf_prog_load.c | 9 ----
> .../test-libbpf-bpf_program__set_insns.c | 8 ----
> .../test-libbpf-btf__load_from_kernel_by_id.c | 8 ----
> .../build/feature/test-libbpf-btf__raw_data.c | 8 ----
> tools/perf/Makefile.config | 48 ++++---------------
> 9 files changed, 10 insertions(+), 102 deletions(-)
> delete mode 100644 tools/build/feature/test-libbpf-bpf_map_create.c
> delete mode 100644 tools/build/feature/test-libbpf-bpf_object__next_map.c
> delete mode 100644 tools/build/feature/test-libbpf-bpf_object__next_program.c
> delete mode 100644 tools/build/feature/test-libbpf-bpf_prog_load.c
> delete mode 100644 tools/build/feature/test-libbpf-bpf_program__set_insns.c
> delete mode 100644 tools/build/feature/test-libbpf-btf__load_from_kernel_by_id.c
> delete mode 100644 tools/build/feature/test-libbpf-btf__raw_data.c
>
> diff --git a/tools/build/feature/Makefile b/tools/build/feature/Makefile
> index 690fe97be190..dc9323e01e42 100644
> --- a/tools/build/feature/Makefile
> +++ b/tools/build/feature/Makefile
> @@ -58,13 +58,6 @@ FILES= \
> test-lzma.bin \
> test-bpf.bin \
> test-libbpf.bin \
> - test-libbpf-btf__load_from_kernel_by_id.bin \
> - test-libbpf-bpf_prog_load.bin \
> - test-libbpf-bpf_map_create.bin \
> - test-libbpf-bpf_object__next_program.bin \
> - test-libbpf-bpf_object__next_map.bin \
> - test-libbpf-bpf_program__set_insns.bin \
> - test-libbpf-btf__raw_data.bin \
> test-get_cpuid.bin \
> test-sdt.bin \
> test-cxx.bin \
> diff --git a/tools/build/feature/test-libbpf-bpf_map_create.c b/tools/build/feature/test-libbpf-bpf_map_create.c
> deleted file mode 100644
> index b9f550e332c8..000000000000
> --- a/tools/build/feature/test-libbpf-bpf_map_create.c
> +++ /dev/null
> @@ -1,8 +0,0 @@
> -// SPDX-License-Identifier: GPL-2.0
> -#include <bpf/bpf.h>
> -
> -int main(void)
> -{
> - return bpf_map_create(0 /* map_type */, NULL /* map_name */, 0, /* key_size */,
> - 0 /* value_size */, 0 /* max_entries */, NULL /* opts */);
> -}
> diff --git a/tools/build/feature/test-libbpf-bpf_object__next_map.c b/tools/build/feature/test-libbpf-bpf_object__next_map.c
> deleted file mode 100644
> index 64adb519e97e..000000000000
> --- a/tools/build/feature/test-libbpf-bpf_object__next_map.c
> +++ /dev/null
> @@ -1,8 +0,0 @@
> -// SPDX-License-Identifier: GPL-2.0
> -#include <bpf/libbpf.h>
> -
> -int main(void)
> -{
> - bpf_object__next_map(NULL /* obj */, NULL /* prev */);
> - return 0;
> -}
> diff --git a/tools/build/feature/test-libbpf-bpf_object__next_program.c b/tools/build/feature/test-libbpf-bpf_object__next_program.c
> deleted file mode 100644
> index 8bf4fd26b545..000000000000
> --- a/tools/build/feature/test-libbpf-bpf_object__next_program.c
> +++ /dev/null
> @@ -1,8 +0,0 @@
> -// SPDX-License-Identifier: GPL-2.0
> -#include <bpf/libbpf.h>
> -
> -int main(void)
> -{
> - bpf_object__next_program(NULL /* obj */, NULL /* prev */);
> - return 0;
> -}
> diff --git a/tools/build/feature/test-libbpf-bpf_prog_load.c b/tools/build/feature/test-libbpf-bpf_prog_load.c
> deleted file mode 100644
> index 47f516d63ebc..000000000000
> --- a/tools/build/feature/test-libbpf-bpf_prog_load.c
> +++ /dev/null
> @@ -1,9 +0,0 @@
> -// SPDX-License-Identifier: GPL-2.0
> -#include <bpf/bpf.h>
> -
> -int main(void)
> -{
> - return bpf_prog_load(0 /* prog_type */, NULL /* prog_name */,
> - NULL /* license */, NULL /* insns */,
> - 0 /* insn_cnt */, NULL /* opts */);
> -}
> diff --git a/tools/build/feature/test-libbpf-bpf_program__set_insns.c b/tools/build/feature/test-libbpf-bpf_program__set_insns.c
> deleted file mode 100644
> index f3b7f18c8f49..000000000000
> --- a/tools/build/feature/test-libbpf-bpf_program__set_insns.c
> +++ /dev/null
> @@ -1,8 +0,0 @@
> -// SPDX-License-Identifier: GPL-2.0
> -#include <bpf/libbpf.h>
> -
> -int main(void)
> -{
> - bpf_program__set_insns(NULL /* prog */, NULL /* new_insns */, 0 /* new_insn_cnt */);
> - return 0;
> -}
> diff --git a/tools/build/feature/test-libbpf-btf__load_from_kernel_by_id.c b/tools/build/feature/test-libbpf-btf__load_from_kernel_by_id.c
> deleted file mode 100644
> index a17647f7d5a4..000000000000
> --- a/tools/build/feature/test-libbpf-btf__load_from_kernel_by_id.c
> +++ /dev/null
> @@ -1,8 +0,0 @@
> -// SPDX-License-Identifier: GPL-2.0
> -#include <bpf/btf.h>
> -
> -int main(void)
> -{
> - btf__load_from_kernel_by_id(20151128);
> - return 0;
> -}
> diff --git a/tools/build/feature/test-libbpf-btf__raw_data.c b/tools/build/feature/test-libbpf-btf__raw_data.c
> deleted file mode 100644
> index 57da31dd7581..000000000000
> --- a/tools/build/feature/test-libbpf-btf__raw_data.c
> +++ /dev/null
> @@ -1,8 +0,0 @@
> -// SPDX-License-Identifier: GPL-2.0
> -#include <bpf/btf.h>
> -
> -int main(void)
> -{
> - btf__raw_data(NULL /* btf_ro */, NULL /* size */);
> - return 0;
> -}
> diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
> index 5b8784675903..5ab7cac48c4a 100644
> --- a/tools/perf/Makefile.config
> +++ b/tools/perf/Makefile.config
> @@ -565,54 +565,26 @@ ifndef NO_LIBELF
>
> # detecting libbpf without LIBBPF_DYNAMIC, so make VF=1 shows libbpf detection status
> $(call feature_check,libbpf)
> +
> + # Feature test requires libbpf 1.0 so we can assume the following:
> + CFLAGS += -DHAVE_LIBBPF_BTF__LOAD_FROM_KERNEL_BY_ID
> + CFLAGS += -DHAVE_LIBBPF_BPF_PROG_LOAD
> + CFLAGS += -DHAVE_LIBBPF_BPF_OBJECT__NEXT_PROGRAM
> + CFLAGS += -DHAVE_LIBBPF_BPF_OBJECT__NEXT_MAP
> + CFLAGS += -DHAVE_LIBBPF_BPF_PROGRAM__SET_INSNS
> + CFLAGS += -DHAVE_LIBBPF_BTF__RAW_DATA
> + CFLAGS += -DHAVE_LIBBPF_BPF_MAP_CREATE
> +
> ifdef LIBBPF_DYNAMIC
> ifeq ($(feature-libbpf), 1)
> EXTLIBS += -lbpf
> $(call detected,CONFIG_LIBBPF_DYNAMIC)
> -
> - $(call feature_check,libbpf-btf__load_from_kernel_by_id)
> - ifeq ($(feature-libbpf-btf__load_from_kernel_by_id), 1)
> - CFLAGS += -DHAVE_LIBBPF_BTF__LOAD_FROM_KERNEL_BY_ID
> - endif
> - $(call feature_check,libbpf-bpf_prog_load)
> - ifeq ($(feature-libbpf-bpf_prog_load), 1)
> - CFLAGS += -DHAVE_LIBBPF_BPF_PROG_LOAD
> - endif
> - $(call feature_check,libbpf-bpf_object__next_program)
> - ifeq ($(feature-libbpf-bpf_object__next_program), 1)
> - CFLAGS += -DHAVE_LIBBPF_BPF_OBJECT__NEXT_PROGRAM
> - endif
> - $(call feature_check,libbpf-bpf_object__next_map)
> - ifeq ($(feature-libbpf-bpf_object__next_map), 1)
> - CFLAGS += -DHAVE_LIBBPF_BPF_OBJECT__NEXT_MAP
> - endif
> - $(call feature_check,libbpf-bpf_program__set_insns)
> - ifeq ($(feature-libbpf-bpf_program__set_insns), 1)
> - CFLAGS += -DHAVE_LIBBPF_BPF_PROGRAM__SET_INSNS
> - else
> - dummy := $(error Error: libbpf devel library needs to be >= 0.8.0 to build with LIBBPF_DYNAMIC, update or build statically with the version that comes with the kernel sources);
> - endif
> - $(call feature_check,libbpf-btf__raw_data)
> - ifeq ($(feature-libbpf-btf__raw_data), 1)
> - CFLAGS += -DHAVE_LIBBPF_BTF__RAW_DATA
> - endif
> - $(call feature_check,libbpf-bpf_map_create)
> - ifeq ($(feature-libbpf-bpf_map_create), 1)
> - CFLAGS += -DHAVE_LIBBPF_BPF_MAP_CREATE
> - endif
> else
> dummy := $(error Error: No libbpf devel library found, please install libbpf-devel);
> endif
> else
> # Libbpf will be built as a static library from tools/lib/bpf.
> LIBBPF_STATIC := 1
> - CFLAGS += -DHAVE_LIBBPF_BTF__LOAD_FROM_KERNEL_BY_ID
> - CFLAGS += -DHAVE_LIBBPF_BPF_PROG_LOAD
> - CFLAGS += -DHAVE_LIBBPF_BPF_OBJECT__NEXT_PROGRAM
> - CFLAGS += -DHAVE_LIBBPF_BPF_OBJECT__NEXT_MAP
> - CFLAGS += -DHAVE_LIBBPF_BPF_PROGRAM__SET_INSNS
> - CFLAGS += -DHAVE_LIBBPF_BTF__RAW_DATA
> - CFLAGS += -DHAVE_LIBBPF_BPF_MAP_CREATE
> endif
> endif
>
> --
> 2.39.0.314.g84b9a713c41-goog

--

- Arnaldo