bpf, samples: Use bpf_probe_read_user where appropriate

Use bpf_probe_read_user() helper instead of bpf_probe_read() for samples that
attach to kprobes probing on user addresses.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/5b0144b3f8e031ec5e2438bd7de8d7877e63bf2f.1572649915.git.daniel@iogearbox.net

samples/bpf/map_perf_test_kern.c

@@ -181,7 +181,7 @@ int stress_lru_hmap_alloc(struct pt_regs *ctx)
 	if (addrlen != sizeof(*in6))
 		return 0;
 
-	ret = bpf_probe_read(test_params.dst6, sizeof(test_params.dst6),
+	ret = bpf_probe_read_user(test_params.dst6, sizeof(test_params.dst6),
 				  &in6->sin6_addr);
 	if (ret)
 		goto done;

samples/bpf/test_map_in_map_kern.c

@@ -118,7 +118,7 @@ int trace_sys_connect(struct pt_regs *ctx)
 	if (addrlen != sizeof(*in6))
 		return 0;
 
-	ret = bpf_probe_read(dst6, sizeof(dst6), &in6->sin6_addr);
+	ret = bpf_probe_read_user(dst6, sizeof(dst6), &in6->sin6_addr);
 	if (ret) {
 		inline_ret = ret;
 		goto done;
@@ -129,7 +129,7 @@ int trace_sys_connect(struct pt_regs *ctx)
 
 	test_case = dst6[7];
 
-	ret = bpf_probe_read(&port, sizeof(port), &in6->sin6_port);
+	ret = bpf_probe_read_user(&port, sizeof(port), &in6->sin6_port);
 	if (ret) {
 		inline_ret = ret;
 		goto done;

samples/bpf/test_probe_write_user_kern.c

@@ -37,7 +37,7 @@ int bpf_prog1(struct pt_regs *ctx)
 	if (sockaddr_len > sizeof(orig_addr))
 		return 0;
 
-	if (bpf_probe_read(&orig_addr, sizeof(orig_addr), sockaddr_arg) != 0)
+	if (bpf_probe_read_user(&orig_addr, sizeof(orig_addr), sockaddr_arg) != 0)
 		return 0;
 
 	mapped_addr = bpf_map_lookup_elem(&dnat_map, &orig_addr);