On Fri, Aug 20, 2021 at 7:59 PM Dave Marchevsky <davemarchevsky@xxxxxx> 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@xxxxxx>
> ---
> 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;
> +
[...]
