[PATCH v1 0/3] Assume libbpf 1.0 in build

[PATCH v1 0/3] Assume libbpf 1.0 in build

[Ian Rogers]

libbpf 1.0 was a major change in API. Perf has partially supported
older libbpf's but an implementation may be:
..
       pr_err("%s: not support, update libbpf\n", __func__);
       return -ENOTSUP;
..

Rather than build a binary that would fail at runtime it is
preferrential just to build libbpf statically and link against
that. The static version is in the kernel tools tree and newer than
1.0.

These patches change the libbpf test to only pass when at least
version 1.0 is installed, then remove the conditional build and
feature logic.

The issue is discussed here:
https://lore.kernel.org/lkml/20230106151320.619514-1-irogers@google.com/

Ian Rogers (3):
  tools build: Pass libbpf feature only if libbpf 1.0+
  perf build: Remove libbpf pre-1.0 feature tests
  perf bpf: Remove pre libbpf 1.0 conditional logic

 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/build/feature/test-libbpf.c             |  4 ++
 tools/perf/Makefile.config                    | 37 +----------
 tools/perf/util/bpf-event.c                   | 66 -------------------
 tools/perf/util/bpf-loader.c                  | 18 -----
 tools/perf/util/bpf_counter.c                 | 18 -----
 13 files changed, 5 insertions(+), 202 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

-- 
2.39.0.314.g84b9a713c41-goog

[PATCH v1 1/3] tools build: Pass libbpf feature only if libbpf 1.0+

[Ian Rogers]

libbpf 1.0 represented a cleanup and stabilization of APIs. Simplify
development by only passing the feature test if libbpf 1.0 is
installed.

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/build/feature/test-libbpf.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/tools/build/feature/test-libbpf.c b/tools/build/feature/test-libbpf.c
index a508756cf4cc..cd9989f52119 100644
--- a/tools/build/feature/test-libbpf.c
+++ b/tools/build/feature/test-libbpf.c
@@ -1,6 +1,10 @@
 // SPDX-License-Identifier: GPL-2.0
 #include <bpf/libbpf.h>
 
+#if !defined(LIBBPF_MAJOR_VERSION) || (LIBBPF_MAJOR_VERSION < 1)
+#error At least libbpf 1.0 is required for Linux tools.
+#endif
+
 int main(void)
 {
 	return bpf_object__open("test") ? 0 : -1;
-- 
2.39.0.314.g84b9a713c41-goog

[PATCH v1 2/3] perf build: Remove libbpf pre-1.0 feature tests

[Ian Rogers]

The feature tests were necessary for libbpf pre-1.0, but as the libbpf
implies at least 1.0 we can remove these now.

Signed-off-by: Ian Rogers <irogers@google.com>
---
 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                    | 46 ++++---------------
 9 files changed, 10 insertions(+), 100 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 7c00ce0a7464..399e03338613 100644
--- a/tools/perf/Makefile.config
+++ b/tools/perf/Makefile.config
@@ -565,52 +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
-          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

[PATCH v1 3/3] perf bpf: Remove pre libbpf 1.0 conditional logic

[Ian Rogers]

Tests are no longer applicable as libbpf 1.0 can be assumed.

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/Makefile.config    |  9 -----
 tools/perf/util/bpf-event.c   | 66 -----------------------------------
 tools/perf/util/bpf-loader.c  | 18 ----------
 tools/perf/util/bpf_counter.c | 18 ----------
 4 files changed, 111 deletions(-)

diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
index 399e03338613..2197970bd503 100644
--- a/tools/perf/Makefile.config
+++ b/tools/perf/Makefile.config
@@ -566,15 +566,6 @@ 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
diff --git a/tools/perf/util/bpf-event.c b/tools/perf/util/bpf-event.c
index cc7c1f90cf62..025f331b3867 100644
--- a/tools/perf/util/bpf-event.c
+++ b/tools/perf/util/bpf-event.c
@@ -22,72 +22,6 @@
 #include "record.h"
 #include "util/synthetic-events.h"
 
-#ifndef HAVE_LIBBPF_BTF__LOAD_FROM_KERNEL_BY_ID
-struct btf *btf__load_from_kernel_by_id(__u32 id)
-{
-       struct btf *btf;
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
-       int err = btf__get_from_id(id, &btf);
-#pragma GCC diagnostic pop
-
-       return err ? ERR_PTR(err) : btf;
-}
-#endif
-
-#ifndef HAVE_LIBBPF_BPF_PROG_LOAD
-LIBBPF_API int bpf_load_program(enum bpf_prog_type type,
-				const struct bpf_insn *insns, size_t insns_cnt,
-				const char *license, __u32 kern_version,
-				char *log_buf, size_t log_buf_sz);
-
-int bpf_prog_load(enum bpf_prog_type prog_type,
-		  const char *prog_name __maybe_unused,
-		  const char *license,
-		  const struct bpf_insn *insns, size_t insn_cnt,
-		  const struct bpf_prog_load_opts *opts)
-{
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
-	return bpf_load_program(prog_type, insns, insn_cnt, license,
-				opts->kern_version, opts->log_buf, opts->log_size);
-#pragma GCC diagnostic pop
-}
-#endif
-
-#ifndef HAVE_LIBBPF_BPF_OBJECT__NEXT_PROGRAM
-struct bpf_program *
-bpf_object__next_program(const struct bpf_object *obj, struct bpf_program *prev)
-{
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
-	return bpf_program__next(prev, obj);
-#pragma GCC diagnostic pop
-}
-#endif
-
-#ifndef HAVE_LIBBPF_BPF_OBJECT__NEXT_MAP
-struct bpf_map *
-bpf_object__next_map(const struct bpf_object *obj, const struct bpf_map *prev)
-{
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
-	return bpf_map__next(prev, obj);
-#pragma GCC diagnostic pop
-}
-#endif
-
-#ifndef HAVE_LIBBPF_BTF__RAW_DATA
-const void *
-btf__raw_data(const struct btf *btf_ro, __u32 *size)
-{
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
-	return btf__get_raw_data(btf_ro, size);
-#pragma GCC diagnostic pop
-}
-#endif
-
 static int snprintf_hex(char *buf, size_t size, unsigned char *data, size_t len)
 {
 	int ret = 0;
diff --git a/tools/perf/util/bpf-loader.c b/tools/perf/util/bpf-loader.c
index 6e9b06cf06ee..44cde27d6389 100644
--- a/tools/perf/util/bpf-loader.c
+++ b/tools/perf/util/bpf-loader.c
@@ -32,24 +32,6 @@
 
 #include <internal/xyarray.h>
 
-#ifndef HAVE_LIBBPF_BPF_PROGRAM__SET_INSNS
-int bpf_program__set_insns(struct bpf_program *prog __maybe_unused,
-			   struct bpf_insn *new_insns __maybe_unused, size_t new_insn_cnt __maybe_unused)
-{
-	pr_err("%s: not support, update libbpf\n", __func__);
-	return -ENOTSUP;
-}
-
-int libbpf_register_prog_handler(const char *sec __maybe_unused,
-                                 enum bpf_prog_type prog_type __maybe_unused,
-                                 enum bpf_attach_type exp_attach_type __maybe_unused,
-                                 const struct libbpf_prog_handler_opts *opts __maybe_unused)
-{
-	pr_err("%s: not support, update libbpf\n", __func__);
-	return -ENOTSUP;
-}
-#endif
-
 /* temporarily disable libbpf deprecation warnings */
 #pragma GCC diagnostic ignored "-Wdeprecated-declarations"
 
diff --git a/tools/perf/util/bpf_counter.c b/tools/perf/util/bpf_counter.c
index eeee899fcf34..aa78a15a6f0a 100644
--- a/tools/perf/util/bpf_counter.c
+++ b/tools/perf/util/bpf_counter.c
@@ -312,24 +312,6 @@ static bool bperf_attr_map_compatible(int attr_map_fd)
 		(map_info.value_size == sizeof(struct perf_event_attr_map_entry));
 }
 
-#ifndef HAVE_LIBBPF_BPF_MAP_CREATE
-LIBBPF_API int bpf_create_map(enum bpf_map_type map_type, int key_size,
-                              int value_size, int max_entries, __u32 map_flags);
-int
-bpf_map_create(enum bpf_map_type map_type,
-	       const char *map_name __maybe_unused,
-	       __u32 key_size,
-	       __u32 value_size,
-	       __u32 max_entries,
-	       const struct bpf_map_create_opts *opts __maybe_unused)
-{
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
-	return bpf_create_map(map_type, key_size, value_size, max_entries, 0);
-#pragma GCC diagnostic pop
-}
-#endif
-
 static int bperf_lock_attr_map(struct target *target)
 {
 	char path[PATH_MAX];
-- 
2.39.0.314.g84b9a713c41-goog

Re: [PATCH v1 0/3] Assume libbpf 1.0 in build

[Jiri Olsa]

On Mon, Jan 09, 2023 at 12:34:21PM -0800, Ian Rogers wrote:
> libbpf 1.0 was a major change in API. Perf has partially supported
> older libbpf's but an implementation may be:
> ..
>        pr_err("%s: not support, update libbpf\n", __func__);
>        return -ENOTSUP;
> ..
> 
> Rather than build a binary that would fail at runtime it is
> preferrential just to build libbpf statically and link against
> that. The static version is in the kernel tools tree and newer than
> 1.0.
> 
> These patches change the libbpf test to only pass when at least
> version 1.0 is installed, then remove the conditional build and
> feature logic.
> 
> The issue is discussed here:
> https://lore.kernel.org/lkml/20230106151320.619514-1-irogers@google.com/
> 
> Ian Rogers (3):
>   tools build: Pass libbpf feature only if libbpf 1.0+
>   perf build: Remove libbpf pre-1.0 feature tests
>   perf bpf: Remove pre libbpf 1.0 conditional logic
> 
>  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/build/feature/test-libbpf.c             |  4 ++
>  tools/perf/Makefile.config                    | 37 +----------
>  tools/perf/util/bpf-event.c                   | 66 -------------------
>  tools/perf/util/bpf-loader.c                  | 18 -----
>  tools/perf/util/bpf_counter.c                 | 18 -----
>  13 files changed, 5 insertions(+), 202 deletions(-)

nice, I like that.. I was able to build perf on fedora
with (dynamic) and without (static) libbpf 1.0 

I hope supporting allowing dynamic link just with libbpf 1.0
won't mess up backport world too much.. cc-ing Michael

other than that looks ok to me

Acked/Tested-by: Jiri Olsa <jolsa@kernel.org>

also for the 2 dependency patches

thanks,
jirka

>  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
> 
> -- 
> 2.39.0.314.g84b9a713c41-goog
> 

Re: [PATCH v1 0/3] Assume libbpf 1.0 in build

[Arnaldo Carvalho de Melo]

Em Tue, Jan 10, 2023 at 01:34:56PM +0100, Jiri Olsa escreveu:
> On Mon, Jan 09, 2023 at 12:34:21PM -0800, Ian Rogers wrote:
> > libbpf 1.0 was a major change in API. Perf has partially supported
> > older libbpf's but an implementation may be:
> > ..
> >        pr_err("%s: not support, update libbpf\n", __func__);
> >        return -ENOTSUP;
> > ..
> > 
> > Rather than build a binary that would fail at runtime it is
> > preferrential just to build libbpf statically and link against
> > that. The static version is in the kernel tools tree and newer than
> > 1.0.
> > 
> > These patches change the libbpf test to only pass when at least
> > version 1.0 is installed, then remove the conditional build and
> > feature logic.
> > 
> > The issue is discussed here:
> > https://lore.kernel.org/lkml/20230106151320.619514-1-irogers@google.com/
> > 
> > Ian Rogers (3):
> >   tools build: Pass libbpf feature only if libbpf 1.0+
> >   perf build: Remove libbpf pre-1.0 feature tests
> >   perf bpf: Remove pre libbpf 1.0 conditional logic
> > 
> >  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/build/feature/test-libbpf.c             |  4 ++
> >  tools/perf/Makefile.config                    | 37 +----------
> >  tools/perf/util/bpf-event.c                   | 66 -------------------
> >  tools/perf/util/bpf-loader.c                  | 18 -----
> >  tools/perf/util/bpf_counter.c                 | 18 -----
> >  13 files changed, 5 insertions(+), 202 deletions(-)
> 
> nice, I like that.. I was able to build perf on fedora
> with (dynamic) and without (static) libbpf 1.0 
> 
> I hope supporting allowing dynamic link just with libbpf 1.0
> won't mess up backport world too much.. cc-ing Michael

Yeah, would be nice to hear from Michael and other distro maintainers.

- Arnaldo
 
> other than that looks ok to me
> 
> Acked/Tested-by: Jiri Olsa <jolsa@kernel.org>
> 
> also for the 2 dependency patches

ok!