From 763af200d6160b2f79f45cbf9a85b8dc6e20f2c7 Mon Sep 17 00:00:00 2001 From: "Daniel T. Lee" Date: Tue, 24 Nov 2020 09:03:07 +0000 Subject: samples: bpf: Refactor ibumad program with libbpf This commit refactors the existing ibumad program with libbpf bpf loader. Attach/detach of Tracepoint bpf programs has been managed with the generic bpf_program__attach() and bpf_link__destroy() from the libbpf. Also, instead of using the previous BPF MAP definition, this commit refactors ibumad MAP definition with the new BTF-defined MAP format. To verify that this bpf program works without an infiniband device, try loading ib_umad kernel module and test the program as follows: # modprobe ib_umad # ./ibumad Moreover, TRACE_HELPERS has been removed from the Makefile since it is not used on this program. Signed-off-by: Daniel T. Lee Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20201124090310.24374-5-danieltimlee@gmail.com --- samples/bpf/Makefile | 2 +- samples/bpf/ibumad_kern.c | 26 ++++++++--------- samples/bpf/ibumad_user.c | 71 +++++++++++++++++++++++++++++++++++------------ 3 files changed, 68 insertions(+), 31 deletions(-) (limited to 'samples') diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile index 3bffd42e1482..09a249477554 100644 --- a/samples/bpf/Makefile +++ b/samples/bpf/Makefile @@ -109,7 +109,7 @@ xsk_fwd-objs := xsk_fwd.o xdp_fwd-objs := xdp_fwd_user.o task_fd_query-objs := task_fd_query_user.o $(TRACE_HELPERS) xdp_sample_pkts-objs := xdp_sample_pkts_user.o $(TRACE_HELPERS) -ibumad-objs := bpf_load.o ibumad_user.o $(TRACE_HELPERS) +ibumad-objs := ibumad_user.o hbm-objs := hbm.o $(CGROUP_HELPERS) # Tell kbuild to always build the programs diff --git a/samples/bpf/ibumad_kern.c b/samples/bpf/ibumad_kern.c index 3a91b4c1989a..26dcd4dde946 100644 --- a/samples/bpf/ibumad_kern.c +++ b/samples/bpf/ibumad_kern.c @@ -16,19 +16,19 @@ #include -struct bpf_map_def SEC("maps") read_count = { - .type = BPF_MAP_TYPE_ARRAY, - .key_size = sizeof(u32), /* class; u32 required */ - .value_size = sizeof(u64), /* count of mads read */ - .max_entries = 256, /* Room for all Classes */ -}; - -struct bpf_map_def SEC("maps") write_count = { - .type = BPF_MAP_TYPE_ARRAY, - .key_size = sizeof(u32), /* class; u32 required */ - .value_size = sizeof(u64), /* count of mads written */ - .max_entries = 256, /* Room for all Classes */ -}; +struct { + __uint(type, BPF_MAP_TYPE_ARRAY); + __type(key, u32); /* class; u32 required */ + __type(value, u64); /* count of mads read */ + __uint(max_entries, 256); /* Room for all Classes */ +} read_count SEC(".maps"); + +struct { + __uint(type, BPF_MAP_TYPE_ARRAY); + __type(key, u32); /* class; u32 required */ + __type(value, u64); /* count of mads written */ + __uint(max_entries, 256); /* Room for all Classes */ +} write_count SEC(".maps"); #undef DEBUG #ifndef DEBUG diff --git a/samples/bpf/ibumad_user.c b/samples/bpf/ibumad_user.c index fa06eef31a84..d83d8102f489 100644 --- a/samples/bpf/ibumad_user.c +++ b/samples/bpf/ibumad_user.c @@ -23,10 +23,15 @@ #include #include -#include "bpf_load.h" +#include #include "bpf_util.h" #include +static struct bpf_link *tp_links[3]; +static struct bpf_object *obj; +static int map_fd[2]; +static int tp_cnt; + static void dump_counts(int fd) { __u32 key; @@ -53,6 +58,11 @@ static void dump_all_counts(void) static void dump_exit(int sig) { dump_all_counts(); + /* Detach tracepoints */ + while (tp_cnt) + bpf_link__destroy(tp_links[--tp_cnt]); + + bpf_object__close(obj); exit(0); } @@ -73,19 +83,11 @@ static void usage(char *cmd) int main(int argc, char **argv) { + struct bpf_program *prog; unsigned long delay = 5; + char filename[256]; int longindex = 0; - int opt; - char bpf_file[256]; - - /* Create the eBPF kernel code path name. - * This follows the pattern of all of the other bpf samples - */ - snprintf(bpf_file, sizeof(bpf_file), "%s_kern.o", argv[0]); - - /* Do one final dump when exiting */ - signal(SIGINT, dump_exit); - signal(SIGTERM, dump_exit); + int opt, err = -1; while ((opt = getopt_long(argc, argv, "hd:rSw", long_options, &longindex)) != -1) { @@ -107,16 +109,51 @@ int main(int argc, char **argv) } } - if (load_bpf_file(bpf_file)) { - fprintf(stderr, "ERROR: failed to load eBPF from file : %s\n", - bpf_file); - return 1; + /* Do one final dump when exiting */ + signal(SIGINT, dump_exit); + signal(SIGTERM, dump_exit); + + snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]); + obj = bpf_object__open_file(filename, NULL); + if (libbpf_get_error(obj)) { + fprintf(stderr, "ERROR: opening BPF object file failed\n"); + return err; + } + + /* load BPF program */ + if (bpf_object__load(obj)) { + fprintf(stderr, "ERROR: loading BPF object file failed\n"); + goto cleanup; + } + + map_fd[0] = bpf_object__find_map_fd_by_name(obj, "read_count"); + map_fd[1] = bpf_object__find_map_fd_by_name(obj, "write_count"); + if (map_fd[0] < 0 || map_fd[1] < 0) { + fprintf(stderr, "ERROR: finding a map in obj file failed\n"); + goto cleanup; + } + + bpf_object__for_each_program(prog, obj) { + tp_links[tp_cnt] = bpf_program__attach(prog); + if (libbpf_get_error(tp_links[tp_cnt])) { + fprintf(stderr, "ERROR: bpf_program__attach failed\n"); + tp_links[tp_cnt] = NULL; + goto cleanup; + } + tp_cnt++; } while (1) { sleep(delay); dump_all_counts(); } + err = 0; + +cleanup: + /* Detach tracepoints */ + while (tp_cnt) + bpf_link__destroy(tp_links[--tp_cnt]); - return 0; + bpf_object__close(obj); + return err; } -- cgit v1.2.3