[PATCH v7 bpf-next 3/9] samples/bpf: xdp_redirect_cpu_user: do not update bpf maps in option loop

Lorenzo Bianconi
2020-07-14T13:57:16Z

Do not update xdp_redirect_cpu maps running while option loop but
defer it after all available options have been parsed. This is a
preliminary patch to pass the program name we want to attach to the
map entries as a user option

Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
---
samples/bpf/xdp_redirect_cpu_user.c | 36 +++++++++++++++++++++--------
1 file changed, 27 insertions(+), 9 deletions(-)

diff --git a/samples/bpf/xdp_redirect_cpu_user.c b/samples/bpf/xdp_redirect_cpu_user.c
index f4e755e0dd73..6bb2d95cb26c 100644
--- a/samples/bpf/xdp_redirect_cpu_user.c
+++ b/samples/bpf/xdp_redirect_cpu_user.c
@@ -681,6 +681,7 @@ int main(int argc, char **argv)
int add_cpu = -1;
int opt, err;
int prog_fd;
+ int *cpu, i;
__u32 qsize;

n_cpus = get_nprocs_conf();
@@ -716,6 +717,13 @@ int main(int argc, char **argv)
}
mark_cpus_unavailable();

+ cpu = malloc(n_cpus * sizeof(int));
+ if (!cpu) {
+ fprintf(stderr, "failed to allocate cpu array\n");
+ return EXIT_FAIL;
+ }
+ memset(cpu, 0, n_cpus * sizeof(int));
+
/* Parse commands line args */
while ((opt = getopt_long(argc, argv, "hSd:s:p:q:c:xzF",
long_options, &longindex)) != -1) {
@@ -760,8 +768,7 @@ int main(int argc, char **argv)
errno, strerror(errno));
goto error;
}
- create_cpu_entry(add_cpu, qsize, added_cpus, true);
- added_cpus++;
+ cpu[added_cpus++] = add_cpu;
break;
case 'q':
qsize = atoi(optarg);
@@ -772,6 +779,7 @@ int main(int argc, char **argv)
case 'h':
error:
default:
+ free(cpu);
usage(argv, obj);
return EXIT_FAIL_OPTION;
}
@@ -784,16 +792,21 @@ int main(int argc, char **argv)
if (ifindex == -1) {
fprintf(stderr, "ERR: required option --dev missing\n");
usage(argv, obj);
- return EXIT_FAIL_OPTION;
+ err = EXIT_FAIL_OPTION;
+ goto out;
}
/* Required option */
if (add_cpu == -1) {
fprintf(stderr, "ERR: required option --cpu missing\n");
fprintf(stderr, " Specify multiple --cpu option to add more\n");
usage(argv, obj);
- return EXIT_FAIL_OPTION;
+ err = EXIT_FAIL_OPTION;
+ goto out;
}

+ for (i = 0; i < added_cpus; i++)
+ create_cpu_entry(cpu[i], qsize, i, true);
+
/* Remove XDP program when program is interrupted or killed */
signal(SIGINT, int_exit);
signal(SIGTERM, int_exit);
@@ -801,27 +814,32 @@ int main(int argc, char **argv)
prog = bpf_object__find_program_by_title(obj, prog_name);
if (!prog) {
fprintf(stderr, "bpf_object__find_program_by_title failed\n");
- return EXIT_FAIL;
+ err = EXIT_FAIL;
+ goto out;
}

prog_fd = bpf_program__fd(prog);
if (prog_fd < 0) {
fprintf(stderr, "bpf_program__fd failed\n");
- return EXIT_FAIL;
+ err = EXIT_FAIL;
+ goto out;
}

if (bpf_set_link_xdp_fd(ifindex, prog_fd, xdp_flags) < 0) {
fprintf(stderr, "link set xdp fd failed\n");
- return EXIT_FAIL_XDP;
+ err = EXIT_FAIL_XDP;
+ goto out;
}

err = bpf_obj_get_info_by_fd(prog_fd, &info, &info_len);
if (err) {
printf("can't get prog info - %s\n", strerror(errno));
- return err;
+ goto out;
}
prog_id = info.id;

stats_poll(interval, use_separators, prog_name, stress_mode);
- return EXIT_OK;
+out:
+ free(cpu);
+ return err;
}
--
2.26.2