selftests: bpf: enable hi32 randomization for all tests

The previous libbpf patch allows user to specify "prog_flags" to bpf
program load APIs. To enable high 32-bit randomization for a test, we need
to set BPF_F_TEST_RND_HI32 in "prog_flags".

To enable such randomization for all tests, we need to make sure all places
are passing BPF_F_TEST_RND_HI32. Changing them one by one is not
convenient, also, it would be better if a test could be switched to
"normal" running mode without code change.

Given the program load APIs used across bpf selftests are mostly:
  bpf_prog_load:      load from file
  bpf_load_program:   load from raw insns

A test_stub.c is implemented for bpf seltests, it offers two functions for
testing purpose:

  bpf_prog_test_load
  bpf_test_load_program

The are the same as "bpf_prog_load" and "bpf_load_program", except they
also set BPF_F_TEST_RND_HI32. Given *_xattr functions are the APIs to
customize any "prog_flags", it makes little sense to put these two
functions into libbpf.

Then, the following CFLAGS are passed to compilations for host programs:
  -Dbpf_prog_load=bpf_prog_test_load
  -Dbpf_load_program=bpf_test_load_program

They migrate the used load APIs to the test version, hence enable high
32-bit randomization for these tests without changing source code.

Besides all these, there are several testcases are using
"bpf_prog_load_attr" directly, their call sites are updated to pass
BPF_F_TEST_RND_HI32.
Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

tools/testing/selftests/bpf/Makefile

@@ -15,7 +15,9 @@ LLC		?= llc
 LLVM_OBJCOPY	?= llvm-objcopy
 LLVM_READELF	?= llvm-readelf
 BTF_PAHOLE	?= pahole
-CFLAGS += -Wall -O2 -I$(APIDIR) -I$(LIBDIR) -I$(BPFDIR) -I$(GENDIR) $(GENFLAGS) -I../../../include
+CFLAGS += -Wall -O2 -I$(APIDIR) -I$(LIBDIR) -I$(BPFDIR) -I$(GENDIR) $(GENFLAGS) -I../../../include \
+	  -Dbpf_prog_load=bpf_prog_test_load \
+	  -Dbpf_load_program=bpf_test_load_program
 LDLIBS += -lcap -lelf -lrt -lpthread
 
 # Order correspond to 'make run_tests' order
@@ -79,9 +81,9 @@ $(OUTPUT)/test_maps: map_tests/*.c
 
 BPFOBJ := $(OUTPUT)/libbpf.a
 
-$(TEST_GEN_PROGS): $(BPFOBJ)
+$(TEST_GEN_PROGS): test_stub.o $(BPFOBJ)
 
-$(TEST_GEN_PROGS_EXTENDED): $(OUTPUT)/libbpf.a
+$(TEST_GEN_PROGS_EXTENDED): test_stub.o $(OUTPUT)/libbpf.a
 
 $(OUTPUT)/test_dev_cgroup: cgroup_helpers.c
 $(OUTPUT)/test_skb_cgroup_id_user: cgroup_helpers.c
@@ -177,7 +179,7 @@ $(ALU32_BUILD_DIR)/test_progs_32: test_progs.c $(OUTPUT)/libbpf.a\
 						$(ALU32_BUILD_DIR)/urandom_read
 	$(CC) $(TEST_PROGS_CFLAGS) $(CFLAGS) \
 		-o $(ALU32_BUILD_DIR)/test_progs_32 \
-		test_progs.c trace_helpers.c prog_tests/*.c \
+		test_progs.c test_stub.c trace_helpers.c prog_tests/*.c \
 		$(OUTPUT)/libbpf.a $(LDLIBS)
 
 $(ALU32_BUILD_DIR)/test_progs_32: $(PROG_TESTS_H)

tools/testing/selftests/bpf/prog_tests/bpf_verif_scale.c

@@ -22,6 +22,7 @@ static int check_load(const char *file, enum bpf_prog_type type)
 	attr.file = file;
 	attr.prog_type = type;
 	attr.log_level = 4;
+	attr.prog_flags = BPF_F_TEST_RND_HI32;
 	err = bpf_prog_load_xattr(&attr, &obj, &prog_fd);
 	bpf_object__close(obj);
 	if (err)

tools/testing/selftests/bpf/test_sock_addr.c

@@ -745,6 +745,7 @@ static int load_path(const struct sock_addr_test *test, const char *path)
 	attr.file = path;
 	attr.prog_type = BPF_PROG_TYPE_CGROUP_SOCK_ADDR;
 	attr.expected_attach_type = test->expected_attach_type;
+	attr.prog_flags = BPF_F_TEST_RND_HI32;
 
 	if (bpf_prog_load_xattr(&attr, &obj, &prog_fd)) {
 		if (test->expected_result != LOAD_REJECT)

tools/testing/selftests/bpf/test_sock_fields.c

@@ -414,6 +414,7 @@ int main(int argc, char **argv)
 	struct bpf_prog_load_attr attr = {
 		.file = "test_sock_fields_kern.o",
 		.prog_type = BPF_PROG_TYPE_CGROUP_SKB,
+		.prog_flags = BPF_F_TEST_RND_HI32,
 	};
 	int cgroup_fd, egress_fd, ingress_fd, err;
 	struct bpf_program *ingress_prog;

tools/testing/selftests/bpf/test_socket_cookie.c

@@ -148,6 +148,7 @@ static int run_test(int cgfd)
 	memset(&attr, 0, sizeof(attr));
 	attr.file = SOCKET_COOKIE_PROG;
 	attr.prog_type = BPF_PROG_TYPE_UNSPEC;
+	attr.prog_flags = BPF_F_TEST_RND_HI32;
 
 	err = bpf_prog_load_xattr(&attr, &pobj, &prog_fd);
 	if (err) {

tools/testing/selftests/bpf/test_stub.c

+// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+/* Copyright (C) 2019 Netronome Systems, Inc. */
+
+#include <bpf/bpf.h>
+#include <bpf/libbpf.h>
+#include <string.h>
+
+int bpf_prog_test_load(const char *file, enum bpf_prog_type type,
+		       struct bpf_object **pobj, int *prog_fd)
+{
+	struct bpf_prog_load_attr attr;
+
+	memset(&attr, 0, sizeof(struct bpf_prog_load_attr));
+	attr.file = file;
+	attr.prog_type = type;
+	attr.expected_attach_type = 0;
+	attr.prog_flags = BPF_F_TEST_RND_HI32;
+
+	return bpf_prog_load_xattr(&attr, pobj, prog_fd);
+}
+
+int bpf_test_load_program(enum bpf_prog_type type, const struct bpf_insn *insns,
+			  size_t insns_cnt, const char *license,
+			  __u32 kern_version, char *log_buf,
+		     size_t log_buf_sz)
+{
+	struct bpf_load_program_attr load_attr;
+
+	memset(&load_attr, 0, sizeof(struct bpf_load_program_attr));
+	load_attr.prog_type = type;
+	load_attr.expected_attach_type = 0;
+	load_attr.name = NULL;
+	load_attr.insns = insns;
+	load_attr.insns_cnt = insns_cnt;
+	load_attr.license = license;
+	load_attr.kern_version = kern_version;
+	load_attr.prog_flags = BPF_F_TEST_RND_HI32;
+
+	return bpf_load_program_xattr(&load_attr, log_buf, log_buf_sz);
+}

tools/testing/selftests/bpf/test_verifier.c

@@ -882,7 +882,7 @@ static void do_test_single(struct bpf_test *test, bool unpriv,
 	if (fixup_skips != skips)
 		return;
 
-	pflags = 0;
+	pflags = BPF_F_TEST_RND_HI32;
 	if (test->flags & F_LOAD_WITH_STRICT_ALIGNMENT)
 		pflags |= BPF_F_STRICT_ALIGNMENT;
 	if (test->flags & F_NEEDS_EFFICIENT_UNALIGNED_ACCESS)