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Message-Id: <1642678950-19584-4-git-send-email-alan.maguire@oracle.com>
Date: Thu, 20 Jan 2022 11:42:30 +0000
From: Alan Maguire <alan.maguire@...cle.com>
To: ast@...nel.org, daniel@...earbox.net, andrii@...nel.org
Cc: kafai@...com, songliubraving@...com, yhs@...com,
john.fastabend@...il.com, kpsingh@...nel.org, jolsa@...nel.org,
sunyucong@...il.com, netdev@...r.kernel.org, bpf@...r.kernel.org,
Alan Maguire <alan.maguire@...cle.com>
Subject: [RFC bpf-next 3/3] selftests/bpf: add tests for u[ret]probe attach by name
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@...cle.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
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