From: Jiri Olsa Date: Tue, 24 May 2022 11:09:42 +0000 (+0200) Subject: perf build: Stop using __weak bpf_object__next_program() to handle older libbpf versions X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=8916d72554e5f06df5ba17bfabc87c7977294ba4;p=linux.git perf build: Stop using __weak bpf_object__next_program() to handle older libbpf versions By adding a feature test for bpf_object__next_program() 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_program.make.output test-libbpf-bpf_object__next_program.c: In function ‘main’: test-libbpf-bpf_object__next_program.c:6:9: error: implicit declaration of function ‘bpf_object__next_program’; did you mean ‘bpf_object__unpin_programs’? [-Werror=implicit-function-declaration] 6 | bpf_object__next_program(NULL /* obj */, NULL /* prev */); | ^~~~~~~~~~~~~~~~~~~~~~~~ | bpf_object__unpin_programs cc1: all warnings being treated as errors $ $ objdump -dS /tmp/build/perf/perf | grep ':' -A20 00000000005b2dc0 : { 5b2dc0: 55 push %rbp 5b2dc1: 48 89 e5 mov %rsp,%rbp 5b2dc4: 48 83 ec 10 sub $0x10,%rsp 5b2dc8: 64 48 8b 04 25 28 00 mov %fs:0x28,%rax 5b2dcf: 00 00 5b2dd1: 48 89 45 f8 mov %rax,-0x8(%rbp) 5b2dd5: 31 c0 xor %eax,%eax return bpf_program__next(prev, obj); 5b2dd7: 48 8b 45 f8 mov -0x8(%rbp),%rax 5b2ddb: 64 48 2b 04 25 28 00 sub %fs:0x28,%rax 5b2de2: 00 00 5b2de4: 75 0f jne 5b2df5 } 5b2de6: c9 leave 5b2de7: 49 89 f8 mov %rdi,%r8 5b2dea: 48 89 f7 mov %rsi,%rdi return bpf_program__next(prev, obj); 5b2ded: 4c 89 c6 mov %r8,%rsi 5b2df0: e9 3b b4 e5 ff jmp 40e230 $ Signed-off-by: Jiri Olsa Tested-by: Arnaldo Carvalho de Melo Cc: Heiko Carstens Cc: Ian Rogers Cc: Ilya Leoshkevich Cc: Sumanth Korikkar Cc: Sven Schnelle Cc: Thomas Richter Cc: Vasily Gorbik Link: http://lore.kernel.org/linux-perf-users/YozLKby7ITEtchC9@krava Signed-off-by: Arnaldo Carvalho de Melo --- diff --git a/tools/build/Makefile.feature b/tools/build/Makefile.feature index fa5f7b7d722cb..64f8cfa6c9af6 100644 --- a/tools/build/Makefile.feature +++ b/tools/build/Makefile.feature @@ -100,6 +100,7 @@ FEATURE_TESTS_EXTRA := \ libbpf \ libbpf-btf__load_from_kernel_by_id \ libbpf-bpf_prog_load \ + libbpf-bpf_object__next_program \ libpfm4 \ libdebuginfod \ clang-bpf-co-re diff --git a/tools/build/feature/Makefile b/tools/build/feature/Makefile index b3fdcc6c5dd78..6eb829704cb93 100644 --- a/tools/build/feature/Makefile +++ b/tools/build/feature/Makefile @@ -59,6 +59,7 @@ FILES= \ test-libbpf.bin \ test-libbpf-btf__load_from_kernel_by_id.bin \ test-libbpf-bpf_prog_load.bin \ + test-libbpf-bpf_object__next_program.bin \ test-get_cpuid.bin \ test-sdt.bin \ test-cxx.bin \ @@ -295,6 +296,9 @@ $(OUTPUT)test-libbpf-btf__load_from_kernel_by_id.bin: $(OUTPUT)test-libbpf-bpf_prog_load.bin: $(BUILD) -lbpf +$(OUTPUT)test-libbpf-bpf_object__next_program.bin: + $(BUILD) -lbpf + $(OUTPUT)test-sdt.bin: $(BUILD) diff --git a/tools/build/feature/test-libbpf-bpf_object__next_program.c b/tools/build/feature/test-libbpf-bpf_object__next_program.c new file mode 100644 index 0000000000000..8bf4fd26b5452 --- /dev/null +++ b/tools/build/feature/test-libbpf-bpf_object__next_program.c @@ -0,0 +1,8 @@ +// SPDX-License-Identifier: GPL-2.0 +#include + +int main(void) +{ + bpf_object__next_program(NULL /* obj */, NULL /* prev */); + return 0; +} diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config index 63c92fdb1df4c..046e10f65ae7a 100644 --- a/tools/perf/Makefile.config +++ b/tools/perf/Makefile.config @@ -577,12 +577,17 @@ ifndef NO_LIBELF ifeq ($(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 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 + CFLAGS += -DHAVE_LIBBPF_BPF_OBJECT__NEXT_PROGRAM endif endif diff --git a/tools/perf/util/bpf-event.c b/tools/perf/util/bpf-event.c index 289bb55aede17..c68d88ca1ecea 100644 --- a/tools/perf/util/bpf-event.c +++ b/tools/perf/util/bpf-event.c @@ -50,7 +50,8 @@ int bpf_prog_load(enum bpf_prog_type prog_type, } #endif -struct bpf_program * __weak +#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 @@ -58,6 +59,7 @@ bpf_object__next_program(const struct bpf_object *obj, struct bpf_program *prev) return bpf_program__next(prev, obj); #pragma GCC diagnostic pop } +#endif struct bpf_map * __weak bpf_object__next_map(const struct bpf_object *obj, const struct bpf_map *prev)