[PATCH bpf-next 1/2] selftests: bpf: use KHDR_INCLUDES for the UAPI headers

["Matthieu Baerts (NGI0)" <matttbe@xxxxxxxxxx>]

Instead of duplicating UAPI header files in 'tools/include/uapi', the
BPF selftests can also look at the header files inside the kernel
source.

To do that, the kernel selftests infrastructure provides the
'KHDR_INCLUDES' variable. This is what is being used in most selftests,
because it is what is recommended in the documentation [1]. If the
selftests are not executed from the kernel sources, it is possible to
override the variable, e.g.

  make KHDR_INCLUDES="-I${HDR_DIR}/include" -C "${KSFT_DIR}"

... where ${HDR_DIR} has been generated by this command:

  make headers_install INSTALL_HDR_PATH="${HDR_DIR}"

Thanks to 'KHDR_INCLUDES', it is no longer needed to duplicate header
files for userspace test programs, and these programs can include UAPI
header files without the 'uapi' prefix.

Note that it is still required to use 'tools/include/uapi' -- APIDIR,
which corresponds to TOOLS_INCLUDES from lib.mk -- for the BPF programs,
not to conflict with what is already defined in vmlinux.h.

Link: https://docs.kernel.org/dev-tools/kselftest.html#contributing-new-tests-details [1]
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@xxxxxxxxxx>
---
 tools/testing/selftests/bpf/Makefile                       | 2 +-
 tools/testing/selftests/bpf/prog_tests/assign_reuse.c      | 2 +-
 tools/testing/selftests/bpf/prog_tests/tc_links.c          | 4 ++--
 tools/testing/selftests/bpf/prog_tests/tc_netkit.c         | 2 +-
 tools/testing/selftests/bpf/prog_tests/tc_opts.c           | 2 +-
 tools/testing/selftests/bpf/prog_tests/user_ringbuf.c      | 2 +-
 tools/testing/selftests/bpf/prog_tests/xdp_bonding.c       | 2 +-
 tools/testing/selftests/bpf/prog_tests/xdp_cpumap_attach.c | 2 +-
 tools/testing/selftests/bpf/prog_tests/xdp_devmap_attach.c | 2 +-
 tools/testing/selftests/bpf/prog_tests/xdp_do_redirect.c   | 2 +-
 tools/testing/selftests/bpf/prog_tests/xdp_link.c          | 2 +-
 tools/testing/selftests/bpf/xdp_features.c                 | 4 ++--
 12 files changed, 14 insertions(+), 14 deletions(-)

diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
index 4eceb491a8ae..6a7aeae7e206 100644
--- a/tools/testing/selftests/bpf/Makefile
+++ b/tools/testing/selftests/bpf/Makefile
@@ -37,7 +37,7 @@ CFLAGS += -g $(OPT_FLAGS) -rdynamic					\
 	  -Wall -Werror -fno-omit-frame-pointer				\
 	  $(GENFLAGS) $(SAN_CFLAGS) $(LIBELF_CFLAGS)			\
 	  -I$(CURDIR) -I$(INCLUDE_DIR) -I$(GENDIR) -I$(LIBDIR)		\
-	  -I$(TOOLSINCDIR) -I$(APIDIR) -I$(OUTPUT)
+	  -I$(TOOLSINCDIR) $(KHDR_INCLUDES) -I$(OUTPUT)
 LDFLAGS += $(SAN_LDFLAGS)
 LDLIBS += $(LIBELF_LIBS) -lz -lrt -lpthread
 
diff --git a/tools/testing/selftests/bpf/prog_tests/assign_reuse.c b/tools/testing/selftests/bpf/prog_tests/assign_reuse.c
index 989ee4d9785b..3d06bf5a1ba4 100644
--- a/tools/testing/selftests/bpf/prog_tests/assign_reuse.c
+++ b/tools/testing/selftests/bpf/prog_tests/assign_reuse.c
@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0
 /* Copyright (c) 2023 Isovalent */
-#include <uapi/linux/if_link.h>
+#include <linux/if_link.h>
 #include <test_progs.h>
 
 #include <netinet/tcp.h>
diff --git a/tools/testing/selftests/bpf/prog_tests/tc_links.c b/tools/testing/selftests/bpf/prog_tests/tc_links.c
index 1af9ec1149aa..532e162185c3 100644
--- a/tools/testing/selftests/bpf/prog_tests/tc_links.c
+++ b/tools/testing/selftests/bpf/prog_tests/tc_links.c
@@ -1,7 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0
 /* Copyright (c) 2023 Isovalent */
-#include <uapi/linux/if_link.h>
-#include <uapi/linux/pkt_sched.h>
+#include <linux/if_link.h>
+#include <linux/pkt_sched.h>
 #include <net/if.h>
 #include <test_progs.h>
 
diff --git a/tools/testing/selftests/bpf/prog_tests/tc_netkit.c b/tools/testing/selftests/bpf/prog_tests/tc_netkit.c
index b9135720024c..1c8b8f03e873 100644
--- a/tools/testing/selftests/bpf/prog_tests/tc_netkit.c
+++ b/tools/testing/selftests/bpf/prog_tests/tc_netkit.c
@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0
 /* Copyright (c) 2023 Isovalent */
-#include <uapi/linux/if_link.h>
+#include <linux/if_link.h>
 #include <net/if.h>
 #include <test_progs.h>
 
diff --git a/tools/testing/selftests/bpf/prog_tests/tc_opts.c b/tools/testing/selftests/bpf/prog_tests/tc_opts.c
index 196abf223465..14aee536c519 100644
--- a/tools/testing/selftests/bpf/prog_tests/tc_opts.c
+++ b/tools/testing/selftests/bpf/prog_tests/tc_opts.c
@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0
 /* Copyright (c) 2023 Isovalent */
-#include <uapi/linux/if_link.h>
+#include <linux/if_link.h>
 #include <net/if.h>
 #include <test_progs.h>
 
diff --git a/tools/testing/selftests/bpf/prog_tests/user_ringbuf.c b/tools/testing/selftests/bpf/prog_tests/user_ringbuf.c
index dfff6feac12c..a37dda1b3cd2 100644
--- a/tools/testing/selftests/bpf/prog_tests/user_ringbuf.c
+++ b/tools/testing/selftests/bpf/prog_tests/user_ringbuf.c
@@ -12,7 +12,7 @@
 #include <sys/syscall.h>
 #include <sys/sysinfo.h>
 #include <test_progs.h>
-#include <uapi/linux/bpf.h>
+#include <linux/bpf.h>
 #include <unistd.h>
 
 #include "user_ringbuf_fail.skel.h"
diff --git a/tools/testing/selftests/bpf/prog_tests/xdp_bonding.c b/tools/testing/selftests/bpf/prog_tests/xdp_bonding.c
index 6d8b54124cb3..ee9bd8606d14 100644
--- a/tools/testing/selftests/bpf/prog_tests/xdp_bonding.c
+++ b/tools/testing/selftests/bpf/prog_tests/xdp_bonding.c
@@ -18,7 +18,7 @@
 #include <linux/if_bonding.h>
 #include <linux/limits.h>
 #include <linux/udp.h>
-#include <uapi/linux/netdev.h>
+#include <linux/netdev.h>
 
 #include "xdp_dummy.skel.h"
 #include "xdp_redirect_multi_kern.skel.h"
diff --git a/tools/testing/selftests/bpf/prog_tests/xdp_cpumap_attach.c b/tools/testing/selftests/bpf/prog_tests/xdp_cpumap_attach.c
index 481626a875d1..e63a193e29e8 100644
--- a/tools/testing/selftests/bpf/prog_tests/xdp_cpumap_attach.c
+++ b/tools/testing/selftests/bpf/prog_tests/xdp_cpumap_attach.c
@@ -1,5 +1,5 @@
 // SPDX-License-Identifier: GPL-2.0
-#include <uapi/linux/bpf.h>
+#include <linux/bpf.h>
 #include <linux/if_link.h>
 #include <test_progs.h>
 
diff --git a/tools/testing/selftests/bpf/prog_tests/xdp_devmap_attach.c b/tools/testing/selftests/bpf/prog_tests/xdp_devmap_attach.c
index ce6812558287..b916fa945b15 100644
--- a/tools/testing/selftests/bpf/prog_tests/xdp_devmap_attach.c
+++ b/tools/testing/selftests/bpf/prog_tests/xdp_devmap_attach.c
@@ -1,5 +1,5 @@
 // SPDX-License-Identifier: GPL-2.0
-#include <uapi/linux/bpf.h>
+#include <linux/bpf.h>
 #include <linux/if_link.h>
 #include <test_progs.h>
 
diff --git a/tools/testing/selftests/bpf/prog_tests/xdp_do_redirect.c b/tools/testing/selftests/bpf/prog_tests/xdp_do_redirect.c
index bad0ea167be7..c40a25837233 100644
--- a/tools/testing/selftests/bpf/prog_tests/xdp_do_redirect.c
+++ b/tools/testing/selftests/bpf/prog_tests/xdp_do_redirect.c
@@ -9,7 +9,7 @@
 #include <linux/in6.h>
 #include <linux/udp.h>
 #include <bpf/bpf_endian.h>
-#include <uapi/linux/netdev.h>
+#include <linux/netdev.h>
 #include "test_xdp_do_redirect.skel.h"
 
 struct udp_packet {
diff --git a/tools/testing/selftests/bpf/prog_tests/xdp_link.c b/tools/testing/selftests/bpf/prog_tests/xdp_link.c
index e7e9f3c22edf..ab92c395a7c7 100644
--- a/tools/testing/selftests/bpf/prog_tests/xdp_link.c
+++ b/tools/testing/selftests/bpf/prog_tests/xdp_link.c
@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0
 /* Copyright (c) 2020 Facebook */
-#include <uapi/linux/if_link.h>
+#include <linux/if_link.h>
 #include <test_progs.h>
 #include "test_xdp_link.skel.h"
 
diff --git a/tools/testing/selftests/bpf/xdp_features.c b/tools/testing/selftests/bpf/xdp_features.c
index 595c79141cf3..99b54674d94e 100644
--- a/tools/testing/selftests/bpf/xdp_features.c
+++ b/tools/testing/selftests/bpf/xdp_features.c
@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0
-#include <uapi/linux/bpf.h>
-#include <uapi/linux/netdev.h>
+#include <linux/bpf.h>
+#include <linux/netdev.h>
 #include <linux/if_link.h>
 #include <signal.h>
 #include <argp.h>

-- 
2.45.2