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>
clang \
libbpf \
libbpf-btf__load_from_kernel_by_id \
+ libbpf-bpf_prog_load \
libpfm4 \
libdebuginfod \
clang-bpf-co-re
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 \
$(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:
$(BUILD)
--- /dev/null
+// SPDX-License-Identifier: GPL-2.0
+#include <bpf/bpf.h>
+
+int main(void)
+{
+ return bpf_prog_load(0 /* prog_type */, NULL /* prog_name */,
+ NULL /* license */, NULL /* insns */,
+ 0 /* insn_cnt */, NULL /* opts */);
+}
ifeq ($(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
else
dummy := $(error Error: No libbpf devel library found, please install libbpf-devel);
endif
else
CFLAGS += -DHAVE_LIBBPF_BTF__LOAD_FROM_KERNEL_BY_ID
+ CFLAGS += -DHAVE_LIBBPF_BPF_PROG_LOAD
endif
endif
}
#endif
-int __weak 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)
+#ifndef HAVE_LIBBPF_BPF_PROG_LOAD
+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"
opts->kern_version, opts->log_buf, opts->log_size);
#pragma GCC diagnostic pop
}
+#endif
struct bpf_program * __weak
bpf_object__next_program(const struct bpf_object *obj, struct bpf_program *prev)