samples, bpf: Refactor pointer error check with libbpf

Current method of checking pointer error is not user friendly. Especially the __must_check define makes this less intuitive. Since, libbpf has an API libbpf_get_error() which checks pointer error, this commit refactors existing pointer error check logic with libbpf.

Daniel T. Lee committed 6 years ago

Commit 0efdcef1 parent 96586dd3 files · +6 −15Browse files

Showing the changes to samples (3 of 3 files). Show all

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3 files

samples/bpf/sampleip_user.c +2 −5
samples/bpf/trace_event_user.c +3 −6
samples/bpf/xdp_redirect_cpu_user.c +1 −4

samples/bpf/sampleip_user.c+2−5

@@ -18,9 +18,6 @@ · 17 unmodified lines
18	18	#include "perf-sys.h"
19	19	#include "trace_helpers.h"
20	20
21		−#define __must_check
22		−#include <linux/err.h>
23		−
24	21	#define DEFAULT_FREQ 99
25	22	#define DEFAULT_SECS 5
26	23	#define MAX_IPS 8192
@@ -57,7 +54,7 @@ static int sampling_start(int freq, struct bpf_program *prog, · 30 unmodified lines
57	54	return 1;
58	55	}
59	56	links[i] = bpf_program__attach_perf_event(prog, pmu_fd);
60		− if (IS_ERR(links[i])) {
	57	+ if (libbpf_get_error(links[i])) {
61	58	fprintf(stderr, "ERROR: Attach perf event\n");
62	59	links[i] = NULL;
63	60	close(pmu_fd);
@@ -182,7 +179,7 @@ int main(int argc, char **argv) · 118 unmodified lines
182	179
183	180	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
184	181	obj = bpf_object__open_file(filename, NULL);
185		− if (IS_ERR(obj)) {
	182	+ if (libbpf_get_error(obj)) {
186	183	fprintf(stderr, "ERROR: opening BPF object file failed\n");
187	184	obj = NULL;
188	185	goto cleanup;

samples/bpf/trace_event_user.c+3−6

@@ -16,9 +16,6 @@ · 15 unmodified lines
16	16	#include "perf-sys.h"
17	17	#include "trace_helpers.h"
18	18
19		−#define __must_check
20		−#include <linux/err.h>
21		−
22	19	#define SAMPLE_FREQ 50
23	20
24	21	static int pid;
@@ -159,7 +156,7 @@ static void test_perf_event_all_cpu(struct perf_event_attr *attr) · 134 unmodified lines
159	156	goto all_cpu_err;
160	157	}
161	158	links[i] = bpf_program__attach_perf_event(prog, pmu_fd);
162		− if (IS_ERR(links[i])) {
	159	+ if (libbpf_get_error(links[i])) {
163	160	printf("bpf_program__attach_perf_event failed\n");
164	161	links[i] = NULL;
165	162	close(pmu_fd);
@@ -198,7 +195,7 @@ static void test_perf_event_task(struct perf_event_attr *attr) · 32 unmodified lines
198	195	goto err;
199	196	}
200	197	link = bpf_program__attach_perf_event(prog, pmu_fd);
201		− if (IS_ERR(link)) {
	198	+ if (libbpf_get_error(link)) {
202	199	printf("bpf_program__attach_perf_event failed\n");
203	200	link = NULL;
204	201	close(pmu_fd);
@@ -314,7 +311,7 @@ int main(int argc, char **argv) · 109 unmodified lines
314	311	}
315	312
316	313	obj = bpf_object__open_file(filename, NULL);
317		− if (IS_ERR(obj)) {
	314	+ if (libbpf_get_error(obj)) {
318	315	printf("opening BPF object file failed\n");
319	316	obj = NULL;
320	317	goto cleanup;

samples/bpf/xdp_redirect_cpu_user.c+1−4

@@ -19,9 +19,6 @@ static const char *__doc__ = · 18 unmodified lines
19	19	#include <time.h>
20	20	#include <linux/limits.h>
21	21
22		−#define __must_check
23		−#include <linux/err.h>
24		−
25	22	#include <arpa/inet.h>
26	23	#include <linux/if_link.h>
27	24
@@ -622,7 +619,7 @@ static struct bpf_link * attach_tp(struct bpf_object *obj, · 594 unmodified lines
622	619	}
623	620
624	621	link = bpf_program__attach_tracepoint(prog, tp_category, tp_name);
625		− if (IS_ERR(link))
	622	+ if (libbpf_get_error(link))
626	623	exit(EXIT_FAIL_BPF);
627	624
628	625	return link;