On 10/23/19 7:42 AM, Carlos Antonio Neira Bustos wrote:

On Wed, Oct 23, 2019 at 03:02:51AM +0000, Yonghong Song wrote:

quoted

On 10/22/19 12:17 PM, Carlos Neira wrote:

quoted

Self tests added for new helper

Please mention the name of the new helper in the commit message.

quoted

Signed-off-by: Carlos Neira <redacted>

LGTM Ack with a few nits below.
Acked-by: Yonghong Song <redacted>

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---
   .../bpf/prog_tests/ns_current_pid_tgid.c      | 87 +++++++++++++++++++
   .../bpf/progs/test_ns_current_pid_tgid.c      | 37 ++++++++
   2 files changed, 124 insertions(+)
   create mode 100644 tools/testing/selftests/bpf/prog_tests/ns_current_pid_tgid.c
   create mode 100644 tools/testing/selftests/bpf/progs/test_ns_current_pid_tgid.c

diff --git a/tools/testing/selftests/bpf/prog_tests/ns_current_pid_tgid.c b/tools/testing/selftests/bpf/prog_tests/ns_current_pid_tgid.c
new file mode 100644
index 000000000000..257f18999bb6
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/ns_current_pid_tgid.c

@@ -0,0 +1,87 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2019 Carlos Neira cneirabustos@gmail.com */
+#include <test_progs.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include <sys/syscall.h>
+
+struct bss {
+	__u64 dev;
+	__u64 ino;
+	__u64 pid_tgid;
+	__u64 user_pid_tgid;
+};
+
+void test_ns_current_pid_tgid(void)
+{
+	const char *probe_name = "raw_tracepoint/sys_enter";
+	const char *file = "test_ns_current_pid_tgid.o";
+	int err, key = 0, duration = 0;
+	struct bpf_link *link = NULL;
+	struct bpf_program *prog;
+	struct bpf_map *bss_map;
+	struct bpf_object *obj;
+	struct bss bss;
+	struct stat st;
+	__u64 id;
+
+	obj = bpf_object__open_file(file, NULL);
+	if (CHECK(IS_ERR(obj), "obj_open", "err %ld\n", PTR_ERR(obj)))
+		return;
+
+	err = bpf_object__load(obj);
+	if (CHECK(err, "obj_load", "err %d errno %d\n", err, errno))
+		goto cleanup;
+
+	bss_map = bpf_object__find_map_by_name(obj, "test_ns_.bss");
+	if (CHECK(!bss_map, "find_bss_map", "failed\n"))
+		goto cleanup;
+
+	prog = bpf_object__find_program_by_title(obj, probe_name);
+	if (CHECK(!prog, "find_prog", "prog '%s' not found\n",
+		  probe_name))
+		goto cleanup;
+
+	memset(&bss, 0, sizeof(bss));
+	pid_t tid = syscall(SYS_gettid);
+	pid_t pid = getpid();
+
+	id = (__u64) tid << 32 | pid;
+	bss.user_pid_tgid = id;
+
+	if (CHECK_FAIL(stat("/proc/self/ns/pid", &st))) {
+		perror("Failed to stat /proc/self/ns/pid");
+		goto cleanup;
+	}
+
+	bss.dev = st.st_dev;
+	bss.ino = st.st_ino;
+
+	err = bpf_map_update_elem(bpf_map__fd(bss_map), &key, &bss, 0);
+	if (CHECK(err, "setting_bss", "failed to set bss : %d\n", err))
+		goto cleanup;
+
+	link = bpf_program__attach_raw_tracepoint(prog, "sys_enter");
+	if (CHECK(IS_ERR(link), "attach_raw_tp", "err %ld\n",
+		  PTR_ERR(link)))
+		goto cleanup;

You already have default link = NULL.
Here, I think you can do
		link = NULL;
		goto cleanup;

quoted

+
+	/* trigger some syscalls */
+	usleep(1);
+
+	err = bpf_map_lookup_elem(bpf_map__fd(bss_map), &key, &bss);
+	if (CHECK(err, "set_bss", "failed to get bss : %d\n", err))
+		goto cleanup;
+
+	if (CHECK(id != bss.pid_tgid, "Compare user pid/tgid vs. bpf pid/tgid",
+		  "User pid/tgid %llu EBPF pid/tgid %llu\n", id, bss.pid_tgid))

EBPF -> BPF?

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+		goto cleanup;
+cleanup:
+

The above empty line can be removed.

quoted

+	if (!IS_ERR_OR_NULL(link)) {

With the above suggested change, you only need to check
	if (!link)

quoted

+		bpf_link__destroy(link);
+		link = NULL;
+	}
+	bpf_object__close(obj);
+}

diff --git a/tools/testing/selftests/bpf/progs/test_ns_current_pid_tgid.c b/tools/testing/selftests/bpf/progs/test_ns_current_pid_tgid.c
new file mode 100644
index 000000000000..cdb77eb1a4fb
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/test_ns_current_pid_tgid.c

@@ -0,0 +1,37 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2019 Carlos Neira cneirabustos@gmail.com */
+
+#include <linux/bpf.h>
+#include <stdint.h>
+#include "bpf_helpers.h"
+
+static volatile struct {
+	__u64 dev;
+	__u64 ino;
+	__u64 pid_tgid;
+	__u64 user_pid_tgid;
+} res;
+
+SEC("raw_tracepoint/sys_enter")
+int trace(void *ctx)
+{
+	__u64  ns_pid_tgid, expected_pid;
+	struct bpf_pidns_info nsdata;
+	__u32 key = 0;
+
+	if (bpf_get_ns_current_pid_tgid(res.dev, res.ino, &nsdata,
+		   sizeof(struct bpf_pidns_info)))
+		return 0;
+
+	ns_pid_tgid = (__u64)nsdata.tgid << 32 | nsdata.pid;
+	expected_pid = res.user_pid_tgid;
+
+	if (expected_pid != ns_pid_tgid)
+		return 0;
+
+	res.pid_tgid = ns_pid_tgid;
+
+	return 0;
+}
+
+char _license[] SEC("license") = "GPL";

The new helper does not require GPL, could you double check this?
The above _license should not be necessary.

Thanks, Yonghong.

Do I need to re-send the series of patches as v16 ? or I could reply to this thread addressing your comments for patch 4/5.

You can wait for Eric's ACK and then resend a new version of the patch 
set with all Ack's.

Thanks again for your support.

Bests