add tests that verify attaching by name for
1. local functions in a program
2. library functions in a shared object; and
3. library functions in a program
...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, but fails with -ESRCH when the format
does not match (the latter is to support backwards-compatibility).
Signed-off-by: Alan Maguire <alan.maguire@xxxxxxxxxx>
---
.../selftests/bpf/prog_tests/attach_probe.c | 89 +++++++++++++++++++++-
.../selftests/bpf/progs/test_attach_probe.c | 37 +++++++++
2 files changed, 123 insertions(+), 3 deletions(-)
diff --git a/tools/testing/selftests/bpf/prog_tests/attach_probe.c b/tools/testing/selftests/bpf/prog_tests/attach_probe.c
index d48f6e5..127c347 100644
--- a/tools/testing/selftests/bpf/prog_tests/attach_probe.c
+++ b/tools/testing/selftests/bpf/prog_tests/attach_probe.c
@@ -11,6 +11,12 @@ static void trigger_func(void)
asm volatile ("");
}
+/* attach point for byname uprobe */
+static void trigger_func2(void)
+{
+ asm volatile ("");
+}
+
void test_attach_probe(void)
{
DECLARE_LIBBPF_OPTS(bpf_uprobe_opts, uprobe_opts);
@@ -19,7 +25,10 @@ void test_attach_probe(void)
struct bpf_link *uprobe_link, *uretprobe_link;
struct test_attach_probe* skel;
ssize_t uprobe_offset, ref_ctr_offset;
+ struct bpf_link *uprobe_err_link;
+ char *libc_path;
bool legacy;
+ char *mem;
/* Check if new-style kprobe/uprobe API is supported.
* Kernels that support new FD-based kprobe and uprobe BPF attachment
@@ -90,9 +99,72 @@ void test_attach_probe(void)
goto cleanup;
skel->links.handle_uretprobe = uretprobe_link;
+ /* verify auto-attach fails for old-style uprobe definition */
+ uprobe_err_link = bpf_program__attach(skel->progs.handle_uprobe_byname);
+ if (!ASSERT_EQ(libbpf_get_error(uprobe_err_link), -ESRCH,
+ "auto-attach should fail for old-style name"))
+ goto cleanup;
+
+ uprobe_opts.func_name = "trigger_func2";
+ uprobe_opts.retprobe = false;
+ uprobe_opts.ref_ctr_offset = 0;
+ skel->links.handle_uprobe_byname =
+ bpf_program__attach_uprobe_opts(skel->progs.handle_uprobe_byname,
+ 0 /* this pid */,
+ "/proc/self/exe",
+ 0, &uprobe_opts);
+ if (!ASSERT_OK_PTR(skel->links.handle_uprobe_byname, "attach_uprobe_byname"))
+ goto cleanup;
+
+ /* verify auto-attach works */
+ skel->links.handle_uretprobe_byname =
+ bpf_program__attach(skel->progs.handle_uretprobe_byname);
+ if (!ASSERT_OK_PTR(skel->links.handle_uretprobe_byname, "attach_uretprobe_byname"))
+ goto cleanup;
+
+ /* 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.
+ */
+ libc_path = get_lib_path("libc-");
+ if (!ASSERT_OK_PTR(libc_path, "get path to libc"))
+ goto cleanup;
+ 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;
+ skel->links.handle_uprobe_byname2 =
+ bpf_program__attach_uprobe_opts(skel->progs.handle_uprobe_byname2,
+ 0 /* this pid */,
+ libc_path,
+ 0, &uprobe_opts);
+ if (!ASSERT_OK_PTR(skel->links.handle_uprobe_byname2, "attach_uprobe_byname2"))
+ goto cleanup;
+
+ uprobe_opts.func_name = "free";
+ uprobe_opts.retprobe = true;
+ skel->links.handle_uretprobe_byname2 =
+ bpf_program__attach_uprobe_opts(skel->progs.handle_uretprobe_byname2,
+ -1 /* any pid */,
+ "/proc/self/exe",
+ 0, &uprobe_opts);
+ if (!ASSERT_OK_PTR(skel->links.handle_uretprobe_byname2, "attach_uretprobe_byname2"))
+ goto cleanup;
+
/* trigger & validate kprobe && kretprobe */
usleep(1);
+ /* trigger & validate shared library u[ret]probes attached by name */
+ mem = malloc(1);
+ free(mem);
+
+ /* trigger & validate uprobe & uretprobe */
+ trigger_func();
+
+ /* trigger & validate uprobe attached by name */
+ trigger_func2();
+
if (CHECK(skel->bss->kprobe_res != 1, "check_kprobe_res",
"wrong kprobe res: %d\n", skel->bss->kprobe_res))
goto cleanup;
@@ -100,9 +172,6 @@ void test_attach_probe(void)
"wrong kretprobe res: %d\n", skel->bss->kretprobe_res))
goto cleanup;
- /* trigger & validate uprobe & uretprobe */
- trigger_func();
-
if (CHECK(skel->bss->uprobe_res != 3, "check_uprobe_res",
"wrong uprobe res: %d\n", skel->bss->uprobe_res))
goto cleanup;
@@ -110,7 +179,21 @@ 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:
+ free(libc_path);
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..9942461c 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 +43,37 @@ 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:trigger_func2")
+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)
+{
+ unsigned int size = PT_REGS_PARM1(ctx);
+
+ /* verify malloc size */
+ if (size == 1)
+ 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
