selftests/bpf: Store BPF object files with .bpf.o extension

BPF object files are, in a way, the final artifact produced as part of
the ahead-of-time compilation process. That makes them somewhat special
compared to "regular" object files, which are a intermediate build
artifacts that can typically be removed safely. As such, it can make
sense to name them differently to make it easier to spot this difference
at a glance.

Among others, libbpf-bootstrap [0] has established the extension .bpf.o
for BPF object files. It seems reasonable to follow this example and
establish the same denomination for selftest build artifacts. To that
end, this change adjusts the corresponding part of the build system and
the test programs loading BPF object files to work with .bpf.o files.

  [0] https://github.com/libbpf/libbpf-bootstrap

Suggested-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Müller <deso@posteo.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20220901222253.1199242-1-deso@posteo.net

1 files changed, 4 insertions, 4 deletions

diff --git a/tools/testing/selftests/bpf/README.rst b/tools/testing/selftests/bpf/README.rst
index eb1b7541f39d..d3c6b3da0bb1 100644
--- a/tools/testing/selftests/bpf/README.rst
+++ b/tools/testing/selftests/bpf/README.rst
@@ -126,11 +126,11 @@ available in 10.0.1. The patch is available in llvm 11.0.0 trunk.
 
 __  https://reviews.llvm.org/D78466
 
-bpf_verif_scale/loop6.o test failure with Clang 12
-==================================================
+bpf_verif_scale/loop6.bpf.o test failure with Clang 12
+======================================================
 
 With Clang 12, the following bpf_verif_scale test failed:
-  * ``bpf_verif_scale/loop6.o``
+  * ``bpf_verif_scale/loop6.bpf.o``
 
 The verifier output looks like
 
@@ -245,7 +245,7 @@ See `kernel llvm reloc`_ for more explanation and some examples.
 Using clang 13 to compile old libbpf which has static linker support,
 there will be a compilation failure::
 
-  libbpf: ELF relo #0 in section #6 has unexpected type 2 in .../bpf_tcp_nogpl.o
+  libbpf: ELF relo #0 in section #6 has unexpected type 2 in .../bpf_tcp_nogpl.bpf.o
 
 Here, ``type 2`` refers to new relocation type ``R_BPF_64_ABS64``.
 To fix this issue, user newer libbpf.