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authorJiri Olsa <jolsa@kernel.org>2022-05-24 13:13:17 +0200
committerArnaldo Carvalho de Melo <acme@redhat.com>2022-05-26 11:02:02 -0300
commit739c9180cfa487cc92e2721e224564e4672c578e (patch)
tree428c2a022eed96e663484887f08ba565fe94fc36 /tools/build
parent8916d72554e5f06df5ba17bfabc87c7977294ba4 (diff)
downloadlinux-739c9180cfa487cc92e2721e224564e4672c578e.tar.bz2
perf build: Stop using __weak bpf_object__next_map() to handle older libbpf versions
By adding a feature test for bpf_object__next_map() and providing a fallback if it isn't present in older versions of libbpf. Committer testing: $ rpm -q libbpf-devel libbpf-devel-0.4.0-2.fc35.x86_64 $ make -C tools/perf LIBBPF_DYNAMIC=1 O=/tmp/build/perf install-bin $ cat /tmp/build/perf/feature/test-libbpf-bpf_object__next_map.make.output test-libbpf-bpf_object__next_map.c: In function ‘main’: test-libbpf-bpf_object__next_map.c:6:9: error: implicit declaration of function ‘bpf_object__next_map’; did you mean ‘bpf_object__next’? [-Werror=implicit-function-declaration] 6 | bpf_object__next_map(NULL /* obj */, NULL /* prev */); | ^~~~~~~~~~~~~~~~~~~~ | bpf_object__next cc1: all warnings being treated as errors $ $ objdump -dS /tmp/build/perf/perf | grep '<bpf_object__next_map>:' -A20 00000000005b2e00 <bpf_object__next_map>: { 5b2e00: 55 push %rbp 5b2e01: 48 89 e5 mov %rsp,%rbp 5b2e04: 48 83 ec 10 sub $0x10,%rsp 5b2e08: 64 48 8b 04 25 28 00 mov %fs:0x28,%rax 5b2e0f: 00 00 5b2e11: 48 89 45 f8 mov %rax,-0x8(%rbp) 5b2e15: 31 c0 xor %eax,%eax return bpf_map__next(prev, obj); 5b2e17: 48 8b 45 f8 mov -0x8(%rbp),%rax 5b2e1b: 64 48 2b 04 25 28 00 sub %fs:0x28,%rax 5b2e22: 00 00 5b2e24: 75 0f jne 5b2e35 <bpf_object__next_map+0x35> } 5b2e26: c9 leave 5b2e27: 49 89 f8 mov %rdi,%r8 5b2e2a: 48 89 f7 mov %rsi,%rdi return bpf_map__next(prev, obj); 5b2e2d: 4c 89 c6 mov %r8,%rsi 5b2e30: e9 cb b1 e5 ff jmp 40e000 <bpf_map__next@plt> $ Signed-off-by: Jiri Olsa <jolsa@kernel.org> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Ian Rogers <irogers@google.com> Cc: Ilya Leoshkevich <iii@linux.ibm.com> Cc: Sumanth Korikkar <sumanthk@linux.ibm.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Thomas Richter <tmricht@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Link: http://lore.kernel.org/linux-perf-users/YozLKby7ITEtchC9@krava Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/build')
-rw-r--r--tools/build/Makefile.feature1
-rw-r--r--tools/build/feature/Makefile4
-rw-r--r--tools/build/feature/test-libbpf-bpf_object__next_map.c8
3 files changed, 13 insertions, 0 deletions
diff --git a/tools/build/Makefile.feature b/tools/build/Makefile.feature
index 64f8cfa6c9af..34cf2bff72ca 100644
--- a/tools/build/Makefile.feature
+++ b/tools/build/Makefile.feature
@@ -101,6 +101,7 @@ FEATURE_TESTS_EXTRA := \
libbpf-btf__load_from_kernel_by_id \
libbpf-bpf_prog_load \
libbpf-bpf_object__next_program \
+ libbpf-bpf_object__next_map \
libpfm4 \
libdebuginfod \
clang-bpf-co-re
diff --git a/tools/build/feature/Makefile b/tools/build/feature/Makefile
index 6eb829704cb9..aecb6a28a770 100644
--- a/tools/build/feature/Makefile
+++ b/tools/build/feature/Makefile
@@ -60,6 +60,7 @@ FILES= \
test-libbpf-btf__load_from_kernel_by_id.bin \
test-libbpf-bpf_prog_load.bin \
test-libbpf-bpf_object__next_program.bin \
+ test-libbpf-bpf_object__next_map.bin \
test-get_cpuid.bin \
test-sdt.bin \
test-cxx.bin \
@@ -299,6 +300,9 @@ $(OUTPUT)test-libbpf-bpf_prog_load.bin:
$(OUTPUT)test-libbpf-bpf_object__next_program.bin:
$(BUILD) -lbpf
+$(OUTPUT)test-libbpf-bpf_object__next_map.bin:
+ $(BUILD) -lbpf
+
$(OUTPUT)test-sdt.bin:
$(BUILD)
diff --git a/tools/build/feature/test-libbpf-bpf_object__next_map.c b/tools/build/feature/test-libbpf-bpf_object__next_map.c
new file mode 100644
index 000000000000..64adb519e97e
--- /dev/null
+++ b/tools/build/feature/test-libbpf-bpf_object__next_map.c
@@ -0,0 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <bpf/libbpf.h>
+
+int main(void)
+{
+ bpf_object__next_map(NULL /* obj */, NULL /* prev */);
+ return 0;
+}