Re: [PATCHv3 bpf-next 17/24] selftests/bpf: Add tracing multi skel/pattern/ids attach tests

[Leon Hwang <leon.hwang@linux.dev>]

On 16/3/26 15:51, Jiri Olsa wrote:
> Adding tests for tracing_multi link attachment via all possible
> libbpf apis - skeleton, function pattern and btf ids.
> 
> Signed-off-by: Jiri Olsa <jolsa@kernel.org>
> ---
>  tools/testing/selftests/bpf/Makefile          |   3 +-
>  .../selftests/bpf/prog_tests/tracing_multi.c  | 245 ++++++++++++++++++
>  .../bpf/progs/tracing_multi_attach.c          |  40 +++
>  .../selftests/bpf/progs/tracing_multi_check.c | 150 +++++++++++
>  4 files changed, 437 insertions(+), 1 deletion(-)
>  create mode 100644 tools/testing/selftests/bpf/prog_tests/tracing_multi.c
>  create mode 100644 tools/testing/selftests/bpf/progs/tracing_multi_attach.c
>  create mode 100644 tools/testing/selftests/bpf/progs/tracing_multi_check.c
> 
> diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
> index 869b582b1d1f..e09beba5674e 100644
> --- a/tools/testing/selftests/bpf/Makefile
> +++ b/tools/testing/selftests/bpf/Makefile
> @@ -485,7 +485,7 @@ SKEL_BLACKLIST := btf__% test_pinning_invalid.c test_sk_assign.c
>  LINKED_SKELS := test_static_linked.skel.h linked_funcs.skel.h		\
>  		linked_vars.skel.h linked_maps.skel.h 			\
>  		test_subskeleton.skel.h test_subskeleton_lib.skel.h	\
> -		test_usdt.skel.h
> +		test_usdt.skel.h tracing_multi.skel.h
>  
>  LSKELS := fexit_sleep.c trace_printk.c trace_vprintk.c map_ptr_kern.c 	\
>  	core_kern.c core_kern_overflow.c test_ringbuf.c			\
> @@ -511,6 +511,7 @@ test_usdt.skel.h-deps := test_usdt.bpf.o test_usdt_multispec.bpf.o
>  xsk_xdp_progs.skel.h-deps := xsk_xdp_progs.bpf.o
>  xdp_hw_metadata.skel.h-deps := xdp_hw_metadata.bpf.o
>  xdp_features.skel.h-deps := xdp_features.bpf.o
> +tracing_multi.skel.h-deps := tracing_multi_attach.bpf.o tracing_multi_check.bpf.o
>  
>  LINKED_BPF_OBJS := $(foreach skel,$(LINKED_SKELS),$($(skel)-deps))
>  LINKED_BPF_SRCS := $(patsubst %.bpf.o,%.c,$(LINKED_BPF_OBJS))
> diff --git a/tools/testing/selftests/bpf/prog_tests/tracing_multi.c b/tools/testing/selftests/bpf/prog_tests/tracing_multi.c
> new file mode 100644
> index 000000000000..cebf4eb68f18
> --- /dev/null
> +++ b/tools/testing/selftests/bpf/prog_tests/tracing_multi.c
> @@ -0,0 +1,245 @@
> +// SPDX-License-Identifier: GPL-2.0
> +
> +#include <test_progs.h>
> +#include <bpf/btf.h>
> +#include <search.h>
> +#include "bpf/libbpf_internal.h"
> +#include "tracing_multi.skel.h"
> +#include "trace_helpers.h"
> +
> +static const char * const bpf_fentry_test[] = {
> +	"bpf_fentry_test1",
> +	"bpf_fentry_test2",
> +	"bpf_fentry_test3",
> +	"bpf_fentry_test4",
> +	"bpf_fentry_test5",
> +	"bpf_fentry_test6",
> +	"bpf_fentry_test7",
> +	"bpf_fentry_test8",
> +	"bpf_fentry_test9",
> +	"bpf_fentry_test10",
> +};
> +
> +#define FUNCS_CNT (ARRAY_SIZE(bpf_fentry_test))
> +
> +static int compare(const void *ppa, const void *ppb)
> +{
> +	const char *pa = *(const char **) ppa;
> +	const char *pb = *(const char **) ppb;
> +
> +	return strcmp(pa, pb);
> +}
> +
> +static __u32 *get_ids(const char * const funcs[], int funcs_cnt, const char *mod)
> +{
> +	struct btf *btf, *vmlinux_btf;
> +	__u32 nr, type_id, cnt = 0;
> +	void *root = NULL;
> +	__u32 *ids = NULL;
> +	int i, err = 0;
> +
> +	btf = btf__load_vmlinux_btf();
> +	if (!ASSERT_OK_PTR(btf, "btf__load_vmlinux_btf"))
> +		return NULL;
> +
> +	if (mod) {
> +		vmlinux_btf = btf;
> +		btf = btf__load_module_btf(mod, vmlinux_btf);
> +		if (!ASSERT_OK_PTR(btf, "btf__load_module_btf"))
> +			return NULL;
                        ^ vmlinux_btf does not get released.

> +	}
> +
> +	ids = calloc(funcs_cnt, sizeof(ids[0]));
> +	if (!ids)
> +		goto out;
> +
> +	/*
> +	 * We sort function names by name and search them
> +	 * below for each function.
> +	 */
> +	for (i = 0; i < funcs_cnt; i++)
> +		tsearch(&funcs[i], &root, compare);
                ^ tdestroy() is missing to free tree nodes?

Thanks,
Leon

[...]