bpf: Abstract loop unrolling pragmas in BPF selftests

[Changes from V1:
- Avoid conflict by rebasing with latest master.]

Some BPF tests use loop unrolling compiler pragmas that are clang
specific and not supported by GCC. These pragmas, along with their
GCC equivalences are:

#pragma clang loop unroll_count(N)
#pragma GCC unroll N

#pragma clang loop unroll(full)
#pragma GCC unroll 65534

#pragma clang loop unroll(disable)
#pragma GCC unroll 1

#pragma unroll [aka #pragma clang loop unroll(enable)]
There is no GCC equivalence to this pragma. It enables unrolling on
loops that the compiler would not ordinarily unroll even with
-O2|-funroll-loops, but it is not equivalent to full unrolling
either.

This patch adds a new header progs/bpf_compiler.h that defines the
following macros, which correspond to each pair of compiler-specific
pragmas above:

__pragma_loop_unroll_count(N)
__pragma_loop_unroll_full
__pragma_loop_no_unroll
__pragma_loop_unroll

The selftests using loop unrolling pragmas are then changed to include
the header and use these macros in place of the explicit pragmas.

Tested in bpf-next master.
No regressions.

Signed-off-by: Jose E. Marchesi <jose.marchesi@oracle.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/bpf/20240208203612.29611-1-jose.marchesi@oracle.com

selftests/bpf: fix lots of silly mistakes pointed out by compiler

Once we enable -Wall for BPF sources, compiler will complain about lots
of unused variables, variables that are set but never read, etc.

Fix all these issues first before enabling -Wall in Makefile.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230309054015.4068562-4-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: Return true/false (not 1/0) from bool functions

Return boolean values ("true" or "false") instead of 1 or 0 from bool
functions. This fixes the following warnings from coccicheck:

tools/testing/selftests/bpf/progs/test_xdp_noinline.c:407:9-10: WARNING:
return of 0/1 in function 'decap_v4' with return type bool
tools/testing/selftests/bpf/progs/test_xdp_noinline.c:389:9-10: WARNING:
return of 0/1 in function 'decap_v6' with return type bool
tools/testing/selftests/bpf/progs/test_xdp_noinline.c:290:9-10: WARNING:
return of 0/1 in function 'encap_v6' with return type bool
tools/testing/selftests/bpf/progs/test_xdp_noinline.c:264:9-10: WARNING:
return of 0/1 in function 'parse_tcp' with return type bool
tools/testing/selftests/bpf/progs/test_xdp_noinline.c:242:9-10: WARNING:
return of 0/1 in function 'parse_udp' with return type bool

Generated by: scripts/coccinelle/misc/boolreturn.cocci

Suggested-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Linkui Xiao <xiaolinkui@kylinos.cn>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/bpf/20220714015647.25074-1-xiaolinkui@kylinos.cn

selftests/bpf: Return true/false (not 1/0) from bool functions

Return boolean values ("true" or "false") instead of 1 or 0 from bool
functions. This fixes the following warnings from coccicheck:

./tools/testing/selftests/bpf/progs/test_xdp_noinline.c:567:9-10: WARNING:
return of 0/1 in function 'get_packet_dst' with return type bool
./tools/testing/selftests/bpf/progs/test_l4lb_noinline.c:221:9-10: WARNING:
return of 0/1 in function 'get_packet_dst' with return type bool

Signed-off-by: Haowen Bai <baihaowen@meizu.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Shuah Khan <skhan@linuxfoundation.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/1648779354-14700-1-git-send-email-baihaowen@meizu.com

selftests/bpf: Normalize XDP section names in selftests

Convert almost all SEC("xdp_blah") uses to strict SEC("xdp") to comply
with strict libbpf 1.0 logic of exact section name match for XDP program
types. There is only one exception, which is only tested through
iproute2 and defines multiple XDP programs within the same BPF object.
Given iproute2 still works in non-strict libbpf mode and it doesn't have
means to specify XDP programs by its name (not section name/title),
leave that single file alone for now until iproute2 gains lookup by
function/program name.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Dave Marchevsky <davemarchevsky@fb.com>
Link: https://lore.kernel.org/bpf/20210928161946.2512801-3-andrii@kernel.org

selftests/bpf: Modernize xdp_noinline test w/ skeleton and __noinline

Update xdp_noinline to use BPF skeleton and force __noinline on helper
sub-programs. Also, split existing logic into v4- and v6-only to complicate
sub-program calling patterns (partially overlapped sets of functions for
entry-level BPF programs).

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200903203542.15944-14-andriin@fb.com

selftests: Use consistent include paths for libbpf

Fix all selftests to include libbpf header files with the bpf/ prefix, to
be consistent with external users of the library. Also ensure that all
includes of exported libbpf header files (those that are exported on 'make
install' of the library) use bracketed includes instead of quoted.

To not break the build, keep the old include path until everything has been
changed to the new one; a subsequent patch will remove that.

Fixes: 6910d7d3867a ("selftests/bpf: Ensure bpf_helper_defs.h are taken from selftests dir")
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/157952560568.1683545.9649335788846513446.stgit@toke.dk

selftests/bpf: Modify a test to check global functions

Make two static functions in test_xdp_noinline.c global:
before: processed 2790 insns
after: processed 2598 insns

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20200110064124.1760511-6-ast@kernel.org

selftests/bpf: fix test_xdp_noinline on s390

test_xdp_noinline fails on s390 due to a handful of endianness issues.
Use ntohs for parsing eth_proto.
Replace bswaps with ntohs/htons.

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Acked-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: convert selftests using BTF-defined maps to new syntax

Convert all the existing selftests that are already using BTF-defined
maps to use new syntax (with no static data initialization).

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

selftests/bpf: convert tests w/ custom values to BTF-defined maps

Convert a bulk of selftests that have maps with custom (not integer) key
and/or value.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

selftests: bpf: Move bpf_printk to bpf_helpers.h

bpf_printk is a macro which is commonly used to print out debug messages
in BPF programs and it was copied in many selftests and samples. Since
all of them include bpf_helpers.h, this change moves the macro there.

Signed-off-by: Michal Rostecki <mrostecki@opensuse.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests: bpf: centre kernel bpf objects under new subdir "progs"

At the moment, all kernel bpf objects are listed under BPF_OBJ_FILES.
Listing them manually sometimes causing patch conflict when people are
adding new testcases simultaneously.

It is better to centre all the related source files under a subdir
"progs", then auto-generate the object file list.

Suggested-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>