diff options
| author | Jiri Olsa <jolsa@kernel.org> | 2022-05-24 13:13:17 +0200 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2022-05-26 11:02:02 -0300 |
| commit | 739c9180cfa487cc92e2721e224564e4672c578e (patch) | |
| tree | 428c2a022eed96e663484887f08ba565fe94fc36 /tools/build | |
| parent | 8916d72554e5f06df5ba17bfabc87c7977294ba4 (diff) | |
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.feature | 1 | ||||
| -rw-r--r-- | tools/build/feature/Makefile | 4 | ||||
| -rw-r--r-- | tools/build/feature/test-libbpf-bpf_object__next_map.c | 8 |
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; +} |