[PATCH bpf-next 1/2] selftests/bpf: Test if bpftool linker handles empty sections

[Eduard Zingerman <eddyz87@xxxxxxxxx>]

Adds two empty functions to linked_funcs[12].c. The functions are
annotated as "naked" and go to a separate section. This section ends
up having size 0. bpftool linker merges content for sections with
identical names. This tests if it can handle empty sections.

Signed-off-by: Eduard Zingerman <eddyz87@xxxxxxxxx>
---
 tools/testing/selftests/bpf/progs/linked_funcs1.c | 3 +++
 tools/testing/selftests/bpf/progs/linked_funcs2.c | 3 +++
 2 files changed, 6 insertions(+)

diff --git a/tools/testing/selftests/bpf/progs/linked_funcs1.c b/tools/testing/selftests/bpf/progs/linked_funcs1.c
index c4b49ceea967..029bb5022ba2 100644
--- a/tools/testing/selftests/bpf/progs/linked_funcs1.c
+++ b/tools/testing/selftests/bpf/progs/linked_funcs1.c
@@ -86,4 +86,7 @@ int BPF_PROG(handler1, struct pt_regs *regs, long id)
 	return 0;
 }
 
+SEC(".empty_section")
+__naked void empty_function1(void) {}
+
 char LICENSE[] SEC("license") = "GPL";
diff --git a/tools/testing/selftests/bpf/progs/linked_funcs2.c b/tools/testing/selftests/bpf/progs/linked_funcs2.c
index 013ff0645f0c..4547c8dfc689 100644
--- a/tools/testing/selftests/bpf/progs/linked_funcs2.c
+++ b/tools/testing/selftests/bpf/progs/linked_funcs2.c
@@ -86,4 +86,7 @@ int BPF_PROG(handler2, struct pt_regs *regs, long id)
 	return 0;
 }
 
+SEC(".empty_section")
+__naked void empty_function2(void) {}
+
 char LICENSE[] SEC("license") = "GPL";
-- 
2.40.0