diff options
author | Jiri Olsa <jolsa@kernel.org> | 2022-05-24 14:04:43 +0300 |
---|---|---|
committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2022-05-26 17:02:02 +0300 |
commit | 5c83eff38194ab2c69a7dc1a64a0a3683f0a3c3a (patch) | |
tree | fa432f2332ecf1f5f3ab7cf989e65da353527ba5 /tools/build/feature | |
parent | 73534617dfa3c4cd95fe5ffaeff5315e9ffc2de6 (diff) | |
download | linux-5c83eff38194ab2c69a7dc1a64a0a3683f0a3c3a.tar.xz |
perf build: Stop using __weak bpf_prog_load() to handle older libbpf versions
By adding a feature test for bpf_prog_load() 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_prog_load.make.output
test-libbpf-bpf_prog_load.c: In function ‘main’:
test-libbpf-bpf_prog_load.c:6:16: error: implicit declaration of function ‘bpf_prog_load’ [-Werror=implicit-function-declaration]
6 | return bpf_prog_load(0 /* prog_type */, NULL /* prog_name */,
| ^~~~~~~~~~~~~
cc1: all warnings being treated as errors
$
$ objdump -dS /tmp/build/perf/perf | grep '<bpf_prog_load>:' -A20
00000000005b2d70 <bpf_prog_load>:
{
5b2d70: 55 push %rbp
5b2d71: 48 89 ce mov %rcx,%rsi
5b2d74: 4c 89 c8 mov %r9,%rax
5b2d77: 49 89 d2 mov %rdx,%r10
5b2d7a: 4c 89 c2 mov %r8,%rdx
5b2d7d: 48 89 e5 mov %rsp,%rbp
5b2d80: 48 83 ec 18 sub $0x18,%rsp
5b2d84: 64 48 8b 0c 25 28 00 mov %fs:0x28,%rcx
5b2d8b: 00 00
5b2d8d: 48 89 4d f8 mov %rcx,-0x8(%rbp)
5b2d91: 31 c9 xor %ecx,%ecx
return bpf_load_program(prog_type, insns, insn_cnt, license,
5b2d93: 41 8b 49 5c mov 0x5c(%r9),%ecx
5b2d97: 51 push %rcx
5b2d98: 4d 8b 49 60 mov 0x60(%r9),%r9
5b2d9c: 4c 89 d1 mov %r10,%rcx
5b2d9f: 44 8b 40 1c mov 0x1c(%rax),%r8d
5b2da3: e8 f8 aa e5 ff call 40d8a0 <bpf_load_program@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/feature')
-rw-r--r-- | tools/build/feature/Makefile | 4 | ||||
-rw-r--r-- | tools/build/feature/test-libbpf-bpf_prog_load.c | 9 |
2 files changed, 13 insertions, 0 deletions
diff --git a/tools/build/feature/Makefile b/tools/build/feature/Makefile index cb4a2a4fa2e4..b3fdcc6c5dd7 100644 --- a/tools/build/feature/Makefile +++ b/tools/build/feature/Makefile @@ -58,6 +58,7 @@ FILES= \ test-bpf.bin \ test-libbpf.bin \ test-libbpf-btf__load_from_kernel_by_id.bin \ + test-libbpf-bpf_prog_load.bin \ test-get_cpuid.bin \ test-sdt.bin \ test-cxx.bin \ @@ -291,6 +292,9 @@ $(OUTPUT)test-libbpf.bin: $(OUTPUT)test-libbpf-btf__load_from_kernel_by_id.bin: $(BUILD) -lbpf +$(OUTPUT)test-libbpf-bpf_prog_load.bin: + $(BUILD) -lbpf + $(OUTPUT)test-sdt.bin: $(BUILD) diff --git a/tools/build/feature/test-libbpf-bpf_prog_load.c b/tools/build/feature/test-libbpf-bpf_prog_load.c new file mode 100644 index 000000000000..47f516d63ebc --- /dev/null +++ b/tools/build/feature/test-libbpf-bpf_prog_load.c @@ -0,0 +1,9 @@ +// 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 */); +} |