samples/bpf: Change _kern suffix to .bpf with syscall tracing program

Currently old compile rule (CLANG-bpf) doesn't contains VMLINUX_H define
flag which is essential for the bpf program that includes "vmlinux.h".
Also old compile rule doesn't directly specify the compile target as bpf,
instead it uses bunch of extra options with clang followed by long chain
of commands. (e.g. clang | opt | llvm-dis | llc)

In Makefile, there is already new compile rule which is more simple and
neat. And it also has -D__VMLINUX_H__ option. By just changing the _kern
suffix to .bpf will inherit the benefit of the new CLANG-BPF compile
target.

Also, this commit adds dummy gnu/stub.h to the samples/bpf directory.
As commit 1c2dd16add7e ("selftests/bpf: get rid of -D__x86_64__") noted,
compiling with 'clang -target bpf' will raise an error with stubs.h
unless workaround (-D__x86_64) is used. This commit solves this problem
by adding dummy stub.h to make /usr/include/features.h to follow the
expected path as the same way selftests/bpf dealt with.

Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20221224071527.2292-4-danieltimlee@gmail.com

12 files changed, 11 insertions, 10 deletions

diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile
index 727da3c5879b2e..22039a0a5b35e7 100644
--- a/samples/bpf/Makefile
+++ b/samples/bpf/Makefile
@@ -125,21 +125,21 @@ always-y += sockex1_kern.o
 always-y += sockex2_kern.o
 always-y += sockex3_kern.o
 always-y += tracex1_kern.o
-always-y += tracex2_kern.o
+always-y += tracex2.bpf.o
 always-y += tracex3_kern.o
 always-y += tracex4_kern.o
 always-y += tracex5_kern.o
 always-y += tracex6_kern.o
 always-y += tracex7_kern.o
 always-y += sock_flags_kern.o
-always-y += test_probe_write_user_kern.o
-always-y += trace_output_kern.o
+always-y += test_probe_write_user.bpf.o
+always-y += trace_output.bpf.o
 always-y += tcbpf1_kern.o
 always-y += tc_l2_redirect_kern.o
 always-y += lathist_kern.o
 always-y += offwaketime_kern.o
 always-y += spintest_kern.o
-always-y += map_perf_test_kern.o
+always-y += map_perf_test.bpf.o
 always-y += test_overhead_tp_kern.o
 always-y += test_overhead_raw_tp_kern.o
 always-y += test_overhead_kprobe_kern.o
@@ -147,7 +147,7 @@ always-y += parse_varlen.o parse_simple.o parse_ldabs.o
 always-y += test_cgrp2_tc_kern.o
 always-y += xdp1_kern.o
 always-y += xdp2_kern.o
-always-y += test_current_task_under_cgroup_kern.o
+always-y += test_current_task_under_cgroup.bpf.o
 always-y += trace_event_kern.o
 always-y += sampleip_kern.o
 always-y += lwt_len_hist_kern.o
diff --git a/samples/bpf/gnu/stubs.h b/samples/bpf/gnu/stubs.h
new file mode 100644
index 00000000000000..719225b1662697
--- /dev/null
+++ b/samples/bpf/gnu/stubs.h
@@ -0,0 +1 @@
+/* dummy .h to trick /usr/include/features.h to work with 'clang -target bpf' */
diff --git a/samples/bpf/map_perf_test_kern.c b/samples/bpf/map_perf_test.bpf.c
index 0c7885057ffeef..0c7885057ffeef 100644
--- a/samples/bpf/map_perf_test_kern.c
+++ b/samples/bpf/map_perf_test.bpf.c
diff --git a/samples/bpf/map_perf_test_user.c b/samples/bpf/map_perf_test_user.c
index 1bb53f4b29e11e..d2fbcf963cdf6d 100644
--- a/samples/bpf/map_perf_test_user.c
+++ b/samples/bpf/map_perf_test_user.c
@@ -443,7 +443,7 @@ int main(int argc, char **argv)
 	if (argc > 4)
 		max_cnt = atoi(argv[4]);
 
-	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
+	snprintf(filename, sizeof(filename), "%s.bpf.o", argv[0]);
 	obj = bpf_object__open_file(filename, NULL);
 	if (libbpf_get_error(obj)) {
 		fprintf(stderr, "ERROR: opening BPF object file failed\n");
diff --git a/samples/bpf/test_current_task_under_cgroup_kern.c b/samples/bpf/test_current_task_under_cgroup.bpf.c
index 0b059cee3cbaf5..0b059cee3cbaf5 100644
--- a/samples/bpf/test_current_task_under_cgroup_kern.c
+++ b/samples/bpf/test_current_task_under_cgroup.bpf.c
diff --git a/samples/bpf/test_current_task_under_cgroup_user.c b/samples/bpf/test_current_task_under_cgroup_user.c
index 6fb25906835e99..9726ed2a8a8bf5 100644
--- a/samples/bpf/test_current_task_under_cgroup_user.c
+++ b/samples/bpf/test_current_task_under_cgroup_user.c
@@ -21,7 +21,7 @@ int main(int argc, char **argv)
 	char filename[256];
 	int map_fd[2];
 
-	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
+	snprintf(filename, sizeof(filename), "%s.bpf.o", argv[0]);
 	obj = bpf_object__open_file(filename, NULL);
 	if (libbpf_get_error(obj)) {
 		fprintf(stderr, "ERROR: opening BPF object file failed\n");
diff --git a/samples/bpf/test_probe_write_user_kern.c b/samples/bpf/test_probe_write_user.bpf.c
index a0f10c5ca273da..a0f10c5ca273da 100644
--- a/samples/bpf/test_probe_write_user_kern.c
+++ b/samples/bpf/test_probe_write_user.bpf.c
diff --git a/samples/bpf/test_probe_write_user_user.c b/samples/bpf/test_probe_write_user_user.c
index 00ccfb834e4567..2a539aec411630 100644
--- a/samples/bpf/test_probe_write_user_user.c
+++ b/samples/bpf/test_probe_write_user_user.c
@@ -24,7 +24,7 @@ int main(int ac, char **argv)
 	mapped_addr_in = (struct sockaddr_in *)&mapped_addr;
 	tmp_addr_in = (struct sockaddr_in *)&tmp_addr;
 
-	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
+	snprintf(filename, sizeof(filename), "%s.bpf.o", argv[0]);
 	obj = bpf_object__open_file(filename, NULL);
 	if (libbpf_get_error(obj)) {
 		fprintf(stderr, "ERROR: opening BPF object file failed\n");
diff --git a/samples/bpf/trace_output_kern.c b/samples/bpf/trace_output.bpf.c
index 565a73b51b04a0..565a73b51b04a0 100644
--- a/samples/bpf/trace_output_kern.c
+++ b/samples/bpf/trace_output.bpf.c
diff --git a/samples/bpf/trace_output_user.c b/samples/bpf/trace_output_user.c
index 371732f9cf8ee0..d316fd2c8e2456 100644
--- a/samples/bpf/trace_output_user.c
+++ b/samples/bpf/trace_output_user.c
@@ -51,7 +51,7 @@ int main(int argc, char **argv)
 	char filename[256];
 	FILE *f;
 
-	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
+	snprintf(filename, sizeof(filename), "%s.bpf.o", argv[0]);
 	obj = bpf_object__open_file(filename, NULL);
 	if (libbpf_get_error(obj)) {
 		fprintf(stderr, "ERROR: opening BPF object file failed\n");
diff --git a/samples/bpf/tracex2_kern.c b/samples/bpf/tracex2.bpf.c
index a712eefc742eab..a712eefc742eab 100644
--- a/samples/bpf/tracex2_kern.c
+++ b/samples/bpf/tracex2.bpf.c
diff --git a/samples/bpf/tracex2_user.c b/samples/bpf/tracex2_user.c
index 089e408abd7ad5..2131f1648cf16d 100644
--- a/samples/bpf/tracex2_user.c
+++ b/samples/bpf/tracex2_user.c
@@ -123,7 +123,7 @@ int main(int ac, char **argv)
 	int i, j = 0;
 	FILE *f;
 
-	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
+	snprintf(filename, sizeof(filename), "%s.bpf.o", argv[0]);
 	obj = bpf_object__open_file(filename, NULL);
 	if (libbpf_get_error(obj)) {
 		fprintf(stderr, "ERROR: opening BPF object file failed\n");