diff mbox series

[bpf-next,5/5] selftests/bpf: add trace_vprintk test prog

Message ID 20210821025837.1614098-6-davemarchevsky@fb.com (mailing list archive)
State Superseded
Delegated to: BPF
Headers show
Series bpf: implement variadic printk helper | expand

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Commit Message

Dave Marchevsky Aug. 21, 2021, 2:58 a.m. UTC 
This commit adds a test prog for vprintk which confirms that:
  * bpf_trace_vprintk is writing to dmesg
  * bpf_vprintk convenience macro works as expected
  * >3 args are printed

Approach and code are borrowed from trace_printk test.

Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
---
 tools/testing/selftests/bpf/Makefile          |  3 +-
 .../selftests/bpf/prog_tests/trace_vprintk.c  | 75 +++++++++++++++++++
 .../selftests/bpf/progs/trace_vprintk.c       | 25 +++++++
 3 files changed, 102 insertions(+), 1 deletion(-)
 create mode 100644 tools/testing/selftests/bpf/prog_tests/trace_vprintk.c
 create mode 100644 tools/testing/selftests/bpf/progs/trace_vprintk.c

Comments

Andrii Nakryiko Aug. 24, 2021, 4:59 a.m. UTC | #1 
On Fri, Aug 20, 2021 at 7:59 PM Dave Marchevsky <davemarchevsky@fb.com> wrote:
>
> This commit adds a test prog for vprintk which confirms that:
>   * bpf_trace_vprintk is writing to dmesg
>   * bpf_vprintk convenience macro works as expected
>   * >3 args are printed
>
> Approach and code are borrowed from trace_printk test.
>
> Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
> ---
>  tools/testing/selftests/bpf/Makefile          |  3 +-
>  .../selftests/bpf/prog_tests/trace_vprintk.c  | 75 +++++++++++++++++++
>  .../selftests/bpf/progs/trace_vprintk.c       | 25 +++++++
>  3 files changed, 102 insertions(+), 1 deletion(-)
>  create mode 100644 tools/testing/selftests/bpf/prog_tests/trace_vprintk.c
>  create mode 100644 tools/testing/selftests/bpf/progs/trace_vprintk.c
>
> diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
> index 2a58b7b5aea4..af5e7a1e9a7c 100644
> --- a/tools/testing/selftests/bpf/Makefile
> +++ b/tools/testing/selftests/bpf/Makefile
> @@ -313,7 +313,8 @@ LINKED_SKELS := test_static_linked.skel.h linked_funcs.skel.h               \
>                 linked_vars.skel.h linked_maps.skel.h
>
>  LSKELS := kfunc_call_test.c fentry_test.c fexit_test.c fexit_sleep.c \
> -       test_ksyms_module.c test_ringbuf.c atomics.c trace_printk.c
> +       test_ksyms_module.c test_ringbuf.c atomics.c trace_printk.c \
> +       trace_vprintk.c
>  SKEL_BLACKLIST += $$(LSKELS)
>
>  test_static_linked.skel.h-deps := test_static_linked1.o test_static_linked2.o
> diff --git a/tools/testing/selftests/bpf/prog_tests/trace_vprintk.c b/tools/testing/selftests/bpf/prog_tests/trace_vprintk.c
> new file mode 100644
> index 000000000000..fd70427d2918
> --- /dev/null
> +++ b/tools/testing/selftests/bpf/prog_tests/trace_vprintk.c
> @@ -0,0 +1,75 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/* Copyright (c) 2021 Facebook */
> +
> +#include <test_progs.h>
> +
> +#include "trace_vprintk.lskel.h"
> +
> +#define TRACEBUF       "/sys/kernel/debug/tracing/trace_pipe"
> +#define SEARCHMSG      "1,2,3,4,5,6,7,8,9,10"
> +
> +void test_trace_vprintk(void)
> +{
> +       int err, iter = 0, duration = 0, found = 0;
> +       struct trace_vprintk__bss *bss;
> +       struct trace_vprintk *skel;
> +       char *buf = NULL;
> +       FILE *fp = NULL;
> +       size_t buflen;
> +
> +       skel = trace_vprintk__open();
> +       if (CHECK(!skel, "skel_open", "failed to open skeleton\n"))
> +               return;

Let's use ASSERT_xxx() in new tests, no new CHECK() uses.


> +
> +       err = trace_vprintk__load(skel);
> +       if (CHECK(err, "skel_load", "failed to load skeleton: %d\n", err))

you should be able to combine open and load into trace_vprintk__open_and_load()

> +               goto cleanup;
> +
> +       bss = skel->bss;
> +
> +       err = trace_vprintk__attach(skel);
> +       if (CHECK(err, "skel_attach", "skeleton attach failed: %d\n", err))
> +               goto cleanup;
> +

[...]
diff mbox series

Patch

diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
index 2a58b7b5aea4..af5e7a1e9a7c 100644
--- a/tools/testing/selftests/bpf/Makefile
+++ b/tools/testing/selftests/bpf/Makefile
@@ -313,7 +313,8 @@  LINKED_SKELS := test_static_linked.skel.h linked_funcs.skel.h		\
 		linked_vars.skel.h linked_maps.skel.h
 
 LSKELS := kfunc_call_test.c fentry_test.c fexit_test.c fexit_sleep.c \
-	test_ksyms_module.c test_ringbuf.c atomics.c trace_printk.c
+	test_ksyms_module.c test_ringbuf.c atomics.c trace_printk.c \
+	trace_vprintk.c
 SKEL_BLACKLIST += $$(LSKELS)
 
 test_static_linked.skel.h-deps := test_static_linked1.o test_static_linked2.o
diff --git a/tools/testing/selftests/bpf/prog_tests/trace_vprintk.c b/tools/testing/selftests/bpf/prog_tests/trace_vprintk.c
new file mode 100644
index 000000000000..fd70427d2918
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/trace_vprintk.c
@@ -0,0 +1,75 @@ 
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2021 Facebook */
+
+#include <test_progs.h>
+
+#include "trace_vprintk.lskel.h"
+
+#define TRACEBUF	"/sys/kernel/debug/tracing/trace_pipe"
+#define SEARCHMSG	"1,2,3,4,5,6,7,8,9,10"
+
+void test_trace_vprintk(void)
+{
+	int err, iter = 0, duration = 0, found = 0;
+	struct trace_vprintk__bss *bss;
+	struct trace_vprintk *skel;
+	char *buf = NULL;
+	FILE *fp = NULL;
+	size_t buflen;
+
+	skel = trace_vprintk__open();
+	if (CHECK(!skel, "skel_open", "failed to open skeleton\n"))
+		return;
+
+	err = trace_vprintk__load(skel);
+	if (CHECK(err, "skel_load", "failed to load skeleton: %d\n", err))
+		goto cleanup;
+
+	bss = skel->bss;
+
+	err = trace_vprintk__attach(skel);
+	if (CHECK(err, "skel_attach", "skeleton attach failed: %d\n", err))
+		goto cleanup;
+
+	fp = fopen(TRACEBUF, "r");
+	if (CHECK(fp == NULL, "could not open trace buffer",
+		  "error %d opening %s", errno, TRACEBUF))
+		goto cleanup;
+
+	/* We do not want to wait forever if this test fails... */
+	fcntl(fileno(fp), F_SETFL, O_NONBLOCK);
+
+	/* wait for tracepoint to trigger */
+	usleep(1);
+	trace_vprintk__detach(skel);
+
+	if (CHECK(bss->trace_vprintk_ran == 0,
+		  "bpf_trace_vprintk never ran",
+		  "ran == %d", bss->trace_vprintk_ran))
+		goto cleanup;
+
+	if (CHECK(bss->trace_vprintk_ret <= 0,
+		  "bpf_trace_vprintk returned <= 0 value",
+		  "got %d", bss->trace_vprintk_ret))
+		goto cleanup;
+
+	/* verify our search string is in the trace buffer */
+	while (getline(&buf, &buflen, fp) >= 0 || errno == EAGAIN) {
+		if (strstr(buf, SEARCHMSG) != NULL)
+			found++;
+		if (found == bss->trace_vprintk_ran)
+			break;
+		if (++iter > 1000)
+			break;
+	}
+
+	if (CHECK(!found, "message from bpf_trace_vprintk not found",
+		  "no instance of %s in %s", SEARCHMSG, TRACEBUF))
+		goto cleanup;
+
+cleanup:
+	trace_vprintk__destroy(skel);
+	free(buf);
+	if (fp)
+		fclose(fp);
+}
diff --git a/tools/testing/selftests/bpf/progs/trace_vprintk.c b/tools/testing/selftests/bpf/progs/trace_vprintk.c
new file mode 100644
index 000000000000..993439a19e1e
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/trace_vprintk.c
@@ -0,0 +1,25 @@ 
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2021 Facebook */
+
+#include "vmlinux.h"
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+
+char _license[] SEC("license") = "GPL";
+
+int trace_vprintk_ret = 0;
+int trace_vprintk_ran = 0;
+
+SEC("fentry/__x64_sys_nanosleep")
+int sys_enter(void *ctx)
+{
+	static const char one[] = "1";
+	static const char three[] = "3";
+	static const char five[] = "5";
+	static const char seven[] = "7";
+	static const char nine[] = "9";
+
+	trace_vprintk_ret = bpf_vprintk("%s,%d,%s,%d,%s,%d,%s,%d,%s,%d %d\n",
+		one, 2, three, 4, five, 6, seven, 8, nine, 10, ++trace_vprintk_ran);
+	return 0;
+}