selftests/bpf: Add tests for u[ret]probe attach by name

add tests that verify attaching by name for

1. local functions in a program
2. 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, but fails with -EOPNOTSUPP with a SEC
name that does not specify binary path/function.

Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/1648654000-21758-5-git-send-email-alan.maguire@oracle.com

1 files changed, 39 insertions, 2 deletions

diff --git a/tools/testing/selftests/bpf/progs/test_attach_probe.c b/tools/testing/selftests/bpf/progs/test_attach_probe.c
index 8056a4c6d918..af994d16bb10 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 kprobe_res = 0;
 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)
@@ -25,18 +29,51 @@ int BPF_KRETPROBE(handle_kretprobe)
 	return 0;
 }
 
-SEC("uprobe/trigger_func")
+SEC("uprobe")
 int handle_uprobe(struct pt_regs *ctx)
 {
 	uprobe_res = 3;
 	return 0;
 }
 
-SEC("uretprobe/trigger_func")
+SEC("uretprobe")
 int handle_uretprobe(struct pt_regs *ctx)
 {
 	uretprobe_res = 4;
 	return 0;
 }
 
+SEC("uprobe")
+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")
+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")
+int handle_uretprobe_byname2(struct pt_regs *ctx)
+{
+	uretprobe_byname2_res = 8;
+	return 0;
+}
+
 char _license[] SEC("license") = "GPL";