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From: Alan Maguire <alan.maguire@oracle.com>
To: ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org
Cc: kafai@fb.com, songliubraving@fb.com, yhs@fb.com,
	john.fastabend@gmail.com, kpsingh@kernel.org, jolsa@kernel.org,
	sunyucong@gmail.com, netdev@vger.kernel.org, bpf@vger.kernel.org,
	Alan Maguire <alan.maguire@oracle.com>
Subject: [RFC bpf-next 3/3] selftests/bpf: add tests for u[ret]probe attach by name
Date: Thu, 20 Jan 2022 11:42:30 +0000	[thread overview]
Message-ID: <1642678950-19584-4-git-send-email-alan.maguire@oracle.com> (raw)
In-Reply-To: <1642678950-19584-1-git-send-email-alan.maguire@oracle.com>

add tests that verify attaching by name for local functions in
a program and library functions in a shared object succeed for
uprobe and uretprobes using new "func_name" option for
bpf_program__attach_uprobe_opts().  Also verify auto-attach
works where uprobe, path to binary and function name are
specified.

Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
---
 .../selftests/bpf/prog_tests/attach_probe.c        | 114 ++++++++++++++++++---
 .../selftests/bpf/progs/test_attach_probe.c        |  33 ++++++
 2 files changed, 130 insertions(+), 17 deletions(-)

diff --git a/tools/testing/selftests/bpf/prog_tests/attach_probe.c b/tools/testing/selftests/bpf/prog_tests/attach_probe.c
index d0bd51e..1bfb09e 100644
--- a/tools/testing/selftests/bpf/prog_tests/attach_probe.c
+++ b/tools/testing/selftests/bpf/prog_tests/attach_probe.c
@@ -10,16 +10,24 @@ static void method(void) {
 	return ;
 }
 
+/* attach point for byname uprobe */
+static void method2(void)
+{
+}
+
 void test_attach_probe(void)
 {
 	DECLARE_LIBBPF_OPTS(bpf_uprobe_opts, uprobe_opts);
 	int duration = 0;
 	struct bpf_link *kprobe_link, *kretprobe_link;
-	struct bpf_link *uprobe_link, *uretprobe_link;
+	struct bpf_link *uprobe_link[3], *uretprobe_link[3];
 	struct test_attach_probe* skel;
 	size_t uprobe_offset;
 	ssize_t base_addr, ref_ctr_offset;
+	char libc_path[256];
 	bool legacy;
+	char *mem;
+	FILE *f;
 
 	/* Check if new-style kprobe/uprobe API is supported.
 	 * Kernels that support new FD-based kprobe and uprobe BPF attachment
@@ -69,14 +77,14 @@ void test_attach_probe(void)
 
 	uprobe_opts.retprobe = false;
 	uprobe_opts.ref_ctr_offset = legacy ? 0 : ref_ctr_offset;
-	uprobe_link = bpf_program__attach_uprobe_opts(skel->progs.handle_uprobe,
-						      0 /* self pid */,
-						      "/proc/self/exe",
-						      uprobe_offset,
-						      &uprobe_opts);
-	if (!ASSERT_OK_PTR(uprobe_link, "attach_uprobe"))
+	uprobe_link[0] = bpf_program__attach_uprobe_opts(skel->progs.handle_uprobe,
+							 0 /* self pid */,
+							 "/proc/self/exe",
+							 uprobe_offset,
+							 &uprobe_opts);
+	if (!ASSERT_OK_PTR(uprobe_link[0], "attach_uprobe"))
 		goto cleanup;
-	skel->links.handle_uprobe = uprobe_link;
+	skel->links.handle_uprobe = uprobe_link[0];
 
 	if (!legacy)
 		ASSERT_GT(uprobe_ref_ctr, 0, "uprobe_ref_ctr_after");
@@ -84,17 +92,79 @@ void test_attach_probe(void)
 	/* if uprobe uses ref_ctr, uretprobe has to use ref_ctr as well */
 	uprobe_opts.retprobe = true;
 	uprobe_opts.ref_ctr_offset = legacy ? 0 : ref_ctr_offset;
-	uretprobe_link = bpf_program__attach_uprobe_opts(skel->progs.handle_uretprobe,
-							 -1 /* any pid */,
+	uretprobe_link[0] = bpf_program__attach_uprobe_opts(skel->progs.handle_uretprobe,
+							    -1 /* any pid */,
+							    "/proc/self/exe",
+							    uprobe_offset, &uprobe_opts);
+	if (!ASSERT_OK_PTR(uretprobe_link[0], "attach_uretprobe"))
+		goto cleanup;
+	skel->links.handle_uretprobe = uretprobe_link[0];
+
+	uprobe_opts.func_name = "method2";
+	uprobe_opts.retprobe = false;
+	uprobe_opts.ref_ctr_offset = 0;
+	uprobe_link[1] = bpf_program__attach_uprobe_opts(skel->progs.handle_uprobe_byname,
+							 0 /* this pid */,
 							 "/proc/self/exe",
-							 uprobe_offset, &uprobe_opts);
-	if (!ASSERT_OK_PTR(uretprobe_link, "attach_uretprobe"))
+							 0, &uprobe_opts);
+	if (!ASSERT_OK_PTR(uprobe_link[1], "attach_uprobe_byname"))
+		goto cleanup;
+	skel->links.handle_uprobe_byname = uprobe_link[1];
+
+	/* verify auto-attach works */
+	uretprobe_link[1] = bpf_program__attach(skel->progs.handle_uretprobe_byname);
+	if (!ASSERT_OK_PTR(uretprobe_link[1], "attach_uretprobe_byname"))
+		goto cleanup;
+	skel->links.handle_uretprobe_byname = uretprobe_link[1];
+
+	/* test attach by name for a library function, using the library
+	 * as the binary argument.  To do this, find path to libc used
+	 * by test_progs via /proc/self/maps.
+	 */
+	f = fopen("/proc/self/maps", "r");
+	if (!ASSERT_OK_PTR(f, "read /proc/self/maps"))
+		goto cleanup;
+	while (fscanf(f, "%*s %*s %*s %*s %*s %[^\n]", libc_path) == 1) {
+		if (strstr(libc_path, "libc-"))
+			break;
+	}
+	fclose(f);
+	if (!ASSERT_NEQ(strstr(libc_path, "libc-"), NULL, "find libc path in /proc/self/maps"))
+		goto cleanup;
+
+	uprobe_opts.func_name = "malloc";
+	uprobe_opts.retprobe = false;
+	uprobe_link[2] = bpf_program__attach_uprobe_opts(skel->progs.handle_uprobe_byname2,
+							  0 /* this pid */,
+							  libc_path,
+							  0, &uprobe_opts);
+	if (!ASSERT_OK_PTR(uprobe_link[2], "attach_uprobe_byname2"))
 		goto cleanup;
-	skel->links.handle_uretprobe = uretprobe_link;
+	skel->links.handle_uprobe_byname2 = uprobe_link[2];
 
-	/* trigger & validate kprobe && kretprobe */
+	uprobe_opts.func_name = "free";
+	uprobe_opts.retprobe = true;
+	uretprobe_link[2] = bpf_program__attach_uprobe_opts(skel->progs.handle_uretprobe_byname2,
+							    -1 /* any pid */,
+							    libc_path,
+							    0, &uprobe_opts);
+	if (!ASSERT_OK_PTR(uretprobe_link[2], "attach_uretprobe_byname2"))
+		goto cleanup;
+	skel->links.handle_uretprobe_byname2 = uretprobe_link[2];
+
+	/* trigger & validate kprobe && kretprobe && uretprobe by name */
 	usleep(1);
 
+	/* trigger & validate shared library u[ret]probes attached by name */
+	mem = malloc(1);
+	free(mem);
+
+	/* trigger & validate uprobe & uretprobe */
+	method();
+
+	/* trigger & validate uprobe attached by name */
+	method2();
+
 	if (CHECK(skel->bss->kprobe_res != 1, "check_kprobe_res",
 		  "wrong kprobe res: %d\n", skel->bss->kprobe_res))
 		goto cleanup;
@@ -102,9 +172,6 @@ void test_attach_probe(void)
 		  "wrong kretprobe res: %d\n", skel->bss->kretprobe_res))
 		goto cleanup;
 
-	/* trigger & validate uprobe & uretprobe */
-	method();
-
 	if (CHECK(skel->bss->uprobe_res != 3, "check_uprobe_res",
 		  "wrong uprobe res: %d\n", skel->bss->uprobe_res))
 		goto cleanup;
@@ -112,6 +179,19 @@ void test_attach_probe(void)
 		  "wrong uretprobe res: %d\n", skel->bss->uretprobe_res))
 		goto cleanup;
 
+	if (CHECK(skel->bss->uprobe_byname_res != 5, "check_uprobe_byname_res",
+		  "wrong uprobe byname res: %d\n", skel->bss->uprobe_byname_res))
+		goto cleanup;
+	if (CHECK(skel->bss->uretprobe_byname_res != 6, "check_uretprobe_byname_res",
+		  "wrong uretprobe byname res: %d\n", skel->bss->uretprobe_byname_res))
+		goto cleanup;
+	if (CHECK(skel->bss->uprobe_byname2_res != 7, "check_uprobe_byname2_res",
+		  "wrong uprobe byname2 res: %d\n", skel->bss->uprobe_byname2_res))
+		goto cleanup;
+	if (CHECK(skel->bss->uretprobe_byname2_res != 8, "check_uretprobe_byname2_res",
+		  "wrong uretprobe byname2 res: %d\n", skel->bss->uretprobe_byname2_res))
+		goto cleanup;
+
 cleanup:
 	test_attach_probe__destroy(skel);
 	ASSERT_EQ(uprobe_ref_ctr, 0, "uprobe_ref_ctr_cleanup");
diff --git a/tools/testing/selftests/bpf/progs/test_attach_probe.c b/tools/testing/selftests/bpf/progs/test_attach_probe.c
index 8056a4c..c176c89 100644
--- a/tools/testing/selftests/bpf/progs/test_attach_probe.c
+++ b/tools/testing/selftests/bpf/progs/test_attach_probe.c
@@ -10,6 +10,10 @@
 int kretprobe_res = 0;
 int uprobe_res = 0;
 int uretprobe_res = 0;
+int uprobe_byname_res = 0;
+int uretprobe_byname_res = 0;
+int uprobe_byname2_res = 0;
+int uretprobe_byname2_res = 0;
 
 SEC("kprobe/sys_nanosleep")
 int handle_kprobe(struct pt_regs *ctx)
@@ -39,4 +43,33 @@ int handle_uretprobe(struct pt_regs *ctx)
 	return 0;
 }
 
+SEC("uprobe/trigger_func_byname")
+int handle_uprobe_byname(struct pt_regs *ctx)
+{
+	uprobe_byname_res = 5;
+	return 0;
+}
+
+/* use auto-attach format for section definition. */
+SEC("uretprobe/proc/self/exe/method2")
+int handle_uretprobe_byname(struct pt_regs *ctx)
+{
+	uretprobe_byname_res = 6;
+	return 0;
+}
+
+SEC("uprobe/trigger_func_byname2")
+int handle_uprobe_byname2(struct pt_regs *ctx)
+{
+	uprobe_byname2_res = 7;
+	return 0;
+}
+
+SEC("uretprobe/trigger_func_byname2")
+int handle_uretprobe_byname2(struct pt_regs *ctx)
+{
+	uretprobe_byname2_res = 8;
+	return 0;
+}
+
 char _license[] SEC("license") = "GPL";
-- 
1.8.3.1


  parent reply	other threads:[~2022-01-20 11:43 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-01-20 11:42 [RFC bpf-next 0/3] libbpf: name-based u[ret]probe attach Alan Maguire
2022-01-20 11:42 ` [RFC bpf-next 1/3] libbpf: support function name-based attach for uprobes Alan Maguire
2022-01-21 19:24   ` Andrii Nakryiko
2022-01-20 11:42 ` [RFC bpf-next 2/3] libbpf: add auto-attach for uprobes based on section name Alan Maguire
2022-01-21 19:33   ` Andrii Nakryiko
2022-01-20 11:42 ` Alan Maguire [this message]
2022-01-21 19:40   ` [RFC bpf-next 3/3] selftests/bpf: add tests for u[ret]probe attach by name Andrii Nakryiko
2022-01-21  1:44 ` [RFC bpf-next 0/3] libbpf: name-based u[ret]probe attach Alexei Starovoitov
2022-01-21 18:15   ` Andrii Nakryiko
2022-01-21 18:20     ` Alexei Starovoitov
2022-01-21 18:27       ` Andrii Nakryiko
2022-01-24 14:13     ` Alan Maguire
2022-01-24 22:47       ` Andrii Nakryiko
2022-01-27 22:54         ` Alan Maguire
2022-01-21 18:31 ` Andrii Nakryiko

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