selftests/bpf: Add uprobe_multi test program

Adding uprobe_multi test program that defines 50k uprobe_multi_func_*
functions and will serve as attach point for uprobe_multi bench test
in following patch.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20230809083440.3209381-23-jolsa@kernel.orgSigned-off-by: Alexei Starovoitov <ast@kernel.org>

tools/testing/selftests/bpf/Makefile

@@ -585,6 +585,7 @@ TRUNNER_EXTRA_FILES := $(OUTPUT)/urandom_read $(OUTPUT)/bpf_testmod.ko	\
 		       $(OUTPUT)/liburandom_read.so			\
 		       $(OUTPUT)/xdp_synproxy				\
 		       $(OUTPUT)/sign-file				\
+		       $(OUTPUT)/uprobe_multi				\
 		       ima_setup.sh 					\
 		       verify_sig_setup.sh				\
 		       $(wildcard progs/btf_dump_test_case_*.c)		\
@@ -698,6 +699,10 @@ $(OUTPUT)/veristat: $(OUTPUT)/veristat.o
 	$(call msg,BINARY,,$@)
 	$(Q)$(CC) $(CFLAGS) $(LDFLAGS) $(filter %.a %.o,$^) $(LDLIBS) -o $@
 
+$(OUTPUT)/uprobe_multi: uprobe_multi.c
+	$(call msg,BINARY,,$@)
+	$(Q)$(CC) $(CFLAGS) $(LDFLAGS) $^ $(LDLIBS) -o $@
+
 EXTRA_CLEAN := $(TEST_CUSTOM_PROGS) $(SCRATCH_DIR) $(HOST_SCRATCH_DIR)	\
 	prog_tests/tests.h map_tests/tests.h verifier/tests.h		\
 	feature bpftool							\

tools/testing/selftests/bpf/uprobe_multi.c

+// SPDX-License-Identifier: GPL-2.0
+
+#include <stdio.h>
+#include <string.h>
+
+#define __PASTE(a, b) a##b
+#define PASTE(a, b) __PASTE(a, b)
+
+#define NAME(name, idx) PASTE(name, idx)
+
+#define DEF(name, idx)  int NAME(name, idx)(void) { return 0; }
+#define CALL(name, idx) NAME(name, idx)();
+
+#define F(body, name, idx) body(name, idx)
+
+#define F10(body, name, idx) \
+	F(body, PASTE(name, idx), 0) F(body, PASTE(name, idx), 1) F(body, PASTE(name, idx), 2) \
+	F(body, PASTE(name, idx), 3) F(body, PASTE(name, idx), 4) F(body, PASTE(name, idx), 5) \
+	F(body, PASTE(name, idx), 6) F(body, PASTE(name, idx), 7) F(body, PASTE(name, idx), 8) \
+	F(body, PASTE(name, idx), 9)
+
+#define F100(body, name, idx) \
+	F10(body, PASTE(name, idx), 0) F10(body, PASTE(name, idx), 1) F10(body, PASTE(name, idx), 2) \
+	F10(body, PASTE(name, idx), 3) F10(body, PASTE(name, idx), 4) F10(body, PASTE(name, idx), 5) \
+	F10(body, PASTE(name, idx), 6) F10(body, PASTE(name, idx), 7) F10(body, PASTE(name, idx), 8) \
+	F10(body, PASTE(name, idx), 9)
+
+#define F1000(body, name, idx) \
+	F100(body, PASTE(name, idx), 0) F100(body, PASTE(name, idx), 1) F100(body, PASTE(name, idx), 2) \
+	F100(body, PASTE(name, idx), 3) F100(body, PASTE(name, idx), 4) F100(body, PASTE(name, idx), 5) \
+	F100(body, PASTE(name, idx), 6) F100(body, PASTE(name, idx), 7) F100(body, PASTE(name, idx), 8) \
+	F100(body, PASTE(name, idx), 9)
+
+#define F10000(body, name, idx) \
+	F1000(body, PASTE(name, idx), 0) F1000(body, PASTE(name, idx), 1) F1000(body, PASTE(name, idx), 2) \
+	F1000(body, PASTE(name, idx), 3) F1000(body, PASTE(name, idx), 4) F1000(body, PASTE(name, idx), 5) \
+	F1000(body, PASTE(name, idx), 6) F1000(body, PASTE(name, idx), 7) F1000(body, PASTE(name, idx), 8) \
+	F1000(body, PASTE(name, idx), 9)
+
+F10000(DEF, uprobe_multi_func_, 0)
+F10000(DEF, uprobe_multi_func_, 1)
+F10000(DEF, uprobe_multi_func_, 2)
+F10000(DEF, uprobe_multi_func_, 3)
+F10000(DEF, uprobe_multi_func_, 4)
+
+static int bench(void)
+{
+	F10000(CALL, uprobe_multi_func_, 0)
+	F10000(CALL, uprobe_multi_func_, 1)
+	F10000(CALL, uprobe_multi_func_, 2)
+	F10000(CALL, uprobe_multi_func_, 3)
+	F10000(CALL, uprobe_multi_func_, 4)
+	return 0;
+}
+
+int main(int argc, char **argv)
+{
+	if (argc != 2)
+		goto error;
+
+	if (!strcmp("bench", argv[1]))
+		return bench();
+
+error:
+	fprintf(stderr, "usage: %s <bench>\n", argv[0]);
+	return -1;
+}