selftests/bpf: Make sure bpf_{g,s}et_retval is exposed everywhere

For each hook, have a simple bpf_set_retval(bpf_get_retval) program
and make sure it loads for the hooks we want. The exceptions are
the hooks which don't propagate the error to the callers:

- sockops
- recvmsg
- getpeername
- getsockname
- cg_skb ingress and egress

Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/r/20220823222555.523590-6-sdf@google.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
index 8d59ec7..eecad99 100644 (file)
--- a/tools/testing/selftests/bpf/Makefile
+++ b/tools/testing/selftests/bpf/Makefile
@@ -323,6 +323,7 @@ $(OUTPUT)/test_l4lb_noinline.o: BPF_CFLAGS += -fno-inline
 $(OUTPUT)/test_xdp_noinline.o: BPF_CFLAGS += -fno-inline
 
 $(OUTPUT)/flow_dissector_load.o: flow_dissector_load.h
+$(OUTPUT)/cgroup_getset_retval_hooks.o: cgroup_getset_retval_hooks.h
 
 # Build BPF object using Clang
 # $1 - input .c file

diff --git a/tools/testing/selftests/bpf/cgroup_getset_retval_hooks.h b/tools/testing/selftests/bpf/cgroup_getset_retval_hooks.h
new file mode 100644 (file)
index 0000000..a525d35
--- /dev/null
+++ b/tools/testing/selftests/bpf/cgroup_getset_retval_hooks.h
@@ -0,0 +1,25 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+BPF_RETVAL_HOOK(ingress, "cgroup_skb/ingress", __sk_buff, -EINVAL)
+BPF_RETVAL_HOOK(egress, "cgroup_skb/egress", __sk_buff, -EINVAL)
+BPF_RETVAL_HOOK(sock_create, "cgroup/sock_create", bpf_sock, 0)
+BPF_RETVAL_HOOK(sock_ops, "sockops", bpf_sock_ops, -EINVAL)
+BPF_RETVAL_HOOK(dev, "cgroup/dev", bpf_cgroup_dev_ctx, 0)
+BPF_RETVAL_HOOK(bind4, "cgroup/bind4", bpf_sock_addr, 0)
+BPF_RETVAL_HOOK(bind6, "cgroup/bind6", bpf_sock_addr, 0)
+BPF_RETVAL_HOOK(connect4, "cgroup/connect4", bpf_sock_addr, 0)
+BPF_RETVAL_HOOK(connect6, "cgroup/connect6", bpf_sock_addr, 0)
+BPF_RETVAL_HOOK(post_bind4, "cgroup/post_bind4", bpf_sock_addr, 0)
+BPF_RETVAL_HOOK(post_bind6, "cgroup/post_bind6", bpf_sock_addr, 0)
+BPF_RETVAL_HOOK(sendmsg4, "cgroup/sendmsg4", bpf_sock_addr, 0)
+BPF_RETVAL_HOOK(sendmsg6, "cgroup/sendmsg6", bpf_sock_addr, 0)
+BPF_RETVAL_HOOK(sysctl, "cgroup/sysctl", bpf_sysctl, 0)
+BPF_RETVAL_HOOK(recvmsg4, "cgroup/recvmsg4", bpf_sock_addr, -EINVAL)
+BPF_RETVAL_HOOK(recvmsg6, "cgroup/recvmsg6", bpf_sock_addr, -EINVAL)
+BPF_RETVAL_HOOK(getsockopt, "cgroup/getsockopt", bpf_sockopt, 0)
+BPF_RETVAL_HOOK(setsockopt, "cgroup/setsockopt", bpf_sockopt, 0)
+BPF_RETVAL_HOOK(getpeername4, "cgroup/getpeername4", bpf_sock_addr, -EINVAL)
+BPF_RETVAL_HOOK(getpeername6, "cgroup/getpeername6", bpf_sock_addr, -EINVAL)
+BPF_RETVAL_HOOK(getsockname4, "cgroup/getsockname4", bpf_sock_addr, -EINVAL)
+BPF_RETVAL_HOOK(getsockname6, "cgroup/getsockname6", bpf_sock_addr, -EINVAL)
+BPF_RETVAL_HOOK(sock_release, "cgroup/sock_release", bpf_sock, 0)

diff --git a/tools/testing/selftests/bpf/prog_tests/cgroup_getset_retval.c b/tools/testing/selftests/bpf/prog_tests/cgroup_getset_retval.c
index 0b47c3c..4d2fa99 100644 (file)
--- a/tools/testing/selftests/bpf/prog_tests/cgroup_getset_retval.c
+++ b/tools/testing/selftests/bpf/prog_tests/cgroup_getset_retval.c
@@ -10,6 +10,7 @@
 
 #include "cgroup_getset_retval_setsockopt.skel.h"
 #include "cgroup_getset_retval_getsockopt.skel.h"
+#include "cgroup_getset_retval_hooks.skel.h"
 
 #define SOL_CUSTOM     0xdeadbeef
 
@@ -433,6 +434,50 @@ close_bpf_object:
        cgroup_getset_retval_getsockopt__destroy(obj);
 }
 
+struct exposed_hook {
+       const char *name;
+       int expected_err;
+} exposed_hooks[] = {
+
+#define BPF_RETVAL_HOOK(NAME, SECTION, CTX, EXPECTED_ERR) \
+       { \
+               .name = #NAME, \
+               .expected_err = EXPECTED_ERR, \
+       },
+
+#include "cgroup_getset_retval_hooks.h"
+
+#undef BPF_RETVAL_HOOK
+};
+
+static void test_exposed_hooks(int cgroup_fd, int sock_fd)
+{
+       struct cgroup_getset_retval_hooks *skel;
+       struct bpf_program *prog;
+       int err;
+       int i;
+
+       for (i = 0; i < ARRAY_SIZE(exposed_hooks); i++) {
+               skel = cgroup_getset_retval_hooks__open();
+               if (!ASSERT_OK_PTR(skel, "cgroup_getset_retval_hooks__open"))
+                       continue;
+
+               prog = bpf_object__find_program_by_name(skel->obj, exposed_hooks[i].name);
+               if (!ASSERT_NEQ(prog, NULL, "bpf_object__find_program_by_name"))
+                       goto close_skel;
+
+               err = bpf_program__set_autoload(prog, true);
+               if (!ASSERT_OK(err, "bpf_program__set_autoload"))
+                       goto close_skel;
+
+               err = cgroup_getset_retval_hooks__load(skel);
+               ASSERT_EQ(err, exposed_hooks[i].expected_err, "expected_err");
+
+close_skel:
+               cgroup_getset_retval_hooks__destroy(skel);
+       }
+}
+
 void test_cgroup_getset_retval(void)
 {
        int cgroup_fd = -1;
@@ -476,6 +521,9 @@ void test_cgroup_getset_retval(void)
        if (test__start_subtest("getsockopt-retval_sync"))
                test_getsockopt_retval_sync(cgroup_fd, sock_fd);
 
+       if (test__start_subtest("exposed_hooks"))
+               test_exposed_hooks(cgroup_fd, sock_fd);
+
 close_fd:
        close(cgroup_fd);
 }

diff --git a/tools/testing/selftests/bpf/progs/cgroup_getset_retval_hooks.c b/tools/testing/selftests/bpf/progs/cgroup_getset_retval_hooks.c
new file mode 100644 (file)
index 0000000..13dfb4b
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/cgroup_getset_retval_hooks.c
@@ -0,0 +1,16 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+
+#define BPF_RETVAL_HOOK(name, section, ctx, expected_err) \
+       __attribute__((__section__("?" section))) \
+       int name(struct ctx *_ctx) \
+       { \
+               bpf_set_retval(bpf_get_retval()); \
+               return 1; \
+       }
+
+#include "cgroup_getset_retval_hooks.h"
+
+#undef BPF_RETVAL_HOOK