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authorDaniel T. Lee <danieltimlee@gmail.com>2020-11-24 09:03:07 +0000
committerAndrii Nakryiko <andrii@kernel.org>2020-11-26 19:33:36 -0800
commit763af200d6160b2f79f45cbf9a85b8dc6e20f2c7 (patch)
tree36ce4d21005b9d35134e33207e2ecf9c901892ed /samples/bpf
parent4fe6641526dbee115d9d037e94a344f4f448aaa4 (diff)
downloadlinux-stericsson-763af200d6160b2f79f45cbf9a85b8dc6e20f2c7.tar.gz
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 <danieltimlee@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20201124090310.24374-5-danieltimlee@gmail.com
Diffstat (limited to 'samples/bpf')
-rw-r--r--samples/bpf/Makefile2
-rw-r--r--samples/bpf/ibumad_kern.c26
-rw-r--r--samples/bpf/ibumad_user.c71
3 files changed, 68 insertions, 31 deletions
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 <bpf/bpf_helpers.h>
-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 <getopt.h>
#include <net/if.h>
-#include "bpf_load.h"
+#include <bpf/bpf.h>
#include "bpf_util.h"
#include <bpf/libbpf.h>
+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;
}