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

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;
  

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