selftests/bpf: Test ldsx with more complex cases
authorYonghong Song <yonghong.song@linux.dev>
Fri, 28 Jul 2023 01:13:36 +0000 (18:13 -0700)
committerAlexei Starovoitov <ast@kernel.org>
Fri, 28 Jul 2023 01:54:17 +0000 (18:54 -0700)
The following ldsx cases are tested:
  - signed readonly map value
  - read/write map value
  - probed memory
  - not-narrowed ctx field access
  - narrowed ctx field access.

Without previous proper verifier/git handling, the test will fail.

If cpuv4 is not supported either by compiler or by jit,
the test will be skipped.

  # ./test_progs -t ldsx_insn
  #113/1   ldsx_insn/map_val and probed_memory:SKIP
  #113/2   ldsx_insn/ctx_member_sign_ext:SKIP
  #113/3   ldsx_insn/ctx_member_narrow_sign_ext:SKIP
  #113     ldsx_insn:SKIP
  Summary: 1/0 PASSED, 3 SKIPPED, 0 FAILED

Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20230728011336.3723434-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c
tools/testing/selftests/bpf/prog_tests/test_ldsx_insn.c [new file with mode: 0644]
tools/testing/selftests/bpf/progs/test_ldsx_insn.c [new file with mode: 0644]

index a6f991b..cefc5dd 100644 (file)
@@ -98,6 +98,12 @@ bpf_testmod_test_struct_arg_8(u64 a, void *b, short c, int d, void *e,
        return bpf_testmod_test_struct_arg_result;
 }
 
+noinline int
+bpf_testmod_test_arg_ptr_to_struct(struct bpf_testmod_struct_arg_1 *a) {
+       bpf_testmod_test_struct_arg_result = a->a;
+       return bpf_testmod_test_struct_arg_result;
+}
+
 __bpf_kfunc void
 bpf_testmod_test_mod_kfunc(int i)
 {
@@ -240,7 +246,7 @@ bpf_testmod_test_read(struct file *file, struct kobject *kobj,
                .off = off,
                .len = len,
        };
-       struct bpf_testmod_struct_arg_1 struct_arg1 = {10};
+       struct bpf_testmod_struct_arg_1 struct_arg1 = {10}, struct_arg1_2 = {-1};
        struct bpf_testmod_struct_arg_2 struct_arg2 = {2, 3};
        struct bpf_testmod_struct_arg_3 *struct_arg3;
        struct bpf_testmod_struct_arg_4 struct_arg4 = {21, 22};
@@ -259,6 +265,7 @@ bpf_testmod_test_read(struct file *file, struct kobject *kobj,
        (void)bpf_testmod_test_struct_arg_8(16, (void *)17, 18, 19,
                                            (void *)20, struct_arg4, 23);
 
+       (void)bpf_testmod_test_arg_ptr_to_struct(&struct_arg1_2);
 
        struct_arg3 = kmalloc((sizeof(struct bpf_testmod_struct_arg_3) +
                                sizeof(int)), GFP_KERNEL);
diff --git a/tools/testing/selftests/bpf/prog_tests/test_ldsx_insn.c b/tools/testing/selftests/bpf/prog_tests/test_ldsx_insn.c
new file mode 100644 (file)
index 0000000..375677c
--- /dev/null
@@ -0,0 +1,139 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2023 Meta Platforms, Inc. and affiliates.*/
+
+#include <test_progs.h>
+#include <network_helpers.h>
+#include "test_ldsx_insn.skel.h"
+
+static void test_map_val_and_probed_memory(void)
+{
+       struct test_ldsx_insn *skel;
+       int err;
+
+       skel = test_ldsx_insn__open();
+       if (!ASSERT_OK_PTR(skel, "test_ldsx_insn__open"))
+               return;
+
+       if (skel->rodata->skip) {
+               test__skip();
+               goto out;
+       }
+
+       bpf_program__set_autoload(skel->progs.rdonly_map_prog, true);
+       bpf_program__set_autoload(skel->progs.map_val_prog, true);
+       bpf_program__set_autoload(skel->progs.test_ptr_struct_arg, true);
+
+       err = test_ldsx_insn__load(skel);
+       if (!ASSERT_OK(err, "test_ldsx_insn__load"))
+               goto out;
+
+       err = test_ldsx_insn__attach(skel);
+       if (!ASSERT_OK(err, "test_ldsx_insn__attach"))
+               goto out;
+
+       ASSERT_OK(trigger_module_test_read(256), "trigger_read");
+
+       ASSERT_EQ(skel->bss->done1, 1, "done1");
+       ASSERT_EQ(skel->bss->ret1, 1, "ret1");
+       ASSERT_EQ(skel->bss->done2, 1, "done2");
+       ASSERT_EQ(skel->bss->ret2, 1, "ret2");
+       ASSERT_EQ(skel->bss->int_member, -1, "int_member");
+
+out:
+       test_ldsx_insn__destroy(skel);
+}
+
+static void test_ctx_member_sign_ext(void)
+{
+       struct test_ldsx_insn *skel;
+       int err, fd, cgroup_fd;
+       char buf[16] = {0};
+       socklen_t optlen;
+
+       cgroup_fd = test__join_cgroup("/ldsx_test");
+       if (!ASSERT_GE(cgroup_fd, 0, "join_cgroup /ldsx_test"))
+               return;
+
+       skel = test_ldsx_insn__open();
+       if (!ASSERT_OK_PTR(skel, "test_ldsx_insn__open"))
+               goto close_cgroup_fd;
+
+       if (skel->rodata->skip) {
+               test__skip();
+               goto destroy_skel;
+       }
+
+       bpf_program__set_autoload(skel->progs._getsockopt, true);
+
+       err = test_ldsx_insn__load(skel);
+       if (!ASSERT_OK(err, "test_ldsx_insn__load"))
+               goto destroy_skel;
+
+       skel->links._getsockopt =
+               bpf_program__attach_cgroup(skel->progs._getsockopt, cgroup_fd);
+       if (!ASSERT_OK_PTR(skel->links._getsockopt, "getsockopt_link"))
+               goto destroy_skel;
+
+       fd = socket(AF_INET, SOCK_STREAM, 0);
+       if (!ASSERT_GE(fd, 0, "socket"))
+               goto destroy_skel;
+
+       optlen = sizeof(buf);
+       (void)getsockopt(fd, SOL_IP, IP_TTL, buf, &optlen);
+
+       ASSERT_EQ(skel->bss->set_optlen, -1, "optlen");
+       ASSERT_EQ(skel->bss->set_retval, -1, "retval");
+
+       close(fd);
+destroy_skel:
+       test_ldsx_insn__destroy(skel);
+close_cgroup_fd:
+       close(cgroup_fd);
+}
+
+static void test_ctx_member_narrow_sign_ext(void)
+{
+       struct test_ldsx_insn *skel;
+       struct __sk_buff skb = {};
+       LIBBPF_OPTS(bpf_test_run_opts, topts,
+                   .data_in = &pkt_v4,
+                   .data_size_in = sizeof(pkt_v4),
+                   .ctx_in = &skb,
+                   .ctx_size_in = sizeof(skb),
+       );
+       int err, prog_fd;
+
+       skel = test_ldsx_insn__open();
+       if (!ASSERT_OK_PTR(skel, "test_ldsx_insn__open"))
+               return;
+
+       if (skel->rodata->skip) {
+               test__skip();
+               goto out;
+       }
+
+       bpf_program__set_autoload(skel->progs._tc, true);
+
+       err = test_ldsx_insn__load(skel);
+       if (!ASSERT_OK(err, "test_ldsx_insn__load"))
+               goto out;
+
+       prog_fd = bpf_program__fd(skel->progs._tc);
+       err = bpf_prog_test_run_opts(prog_fd, &topts);
+       ASSERT_OK(err, "test_run");
+
+       ASSERT_EQ(skel->bss->set_mark, -2, "set_mark");
+
+out:
+       test_ldsx_insn__destroy(skel);
+}
+
+void test_ldsx_insn(void)
+{
+       if (test__start_subtest("map_val and probed_memory"))
+               test_map_val_and_probed_memory();
+       if (test__start_subtest("ctx_member_sign_ext"))
+               test_ctx_member_sign_ext();
+       if (test__start_subtest("ctx_member_narrow_sign_ext"))
+               test_ctx_member_narrow_sign_ext();
+}
diff --git a/tools/testing/selftests/bpf/progs/test_ldsx_insn.c b/tools/testing/selftests/bpf/progs/test_ldsx_insn.c
new file mode 100644 (file)
index 0000000..321abf8
--- /dev/null
@@ -0,0 +1,118 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2023 Meta Platforms, Inc. and affiliates. */
+
+#include "vmlinux.h"
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+
+#if defined(__TARGET_ARCH_x86) && __clang_major__ >= 18
+const volatile int skip = 0;
+#else
+const volatile int skip = 1;
+#endif
+
+volatile const short val1 = -1;
+volatile const int val2 = -1;
+short val3 = -1;
+int val4 = -1;
+int done1, done2, ret1, ret2;
+
+SEC("?raw_tp/sys_enter")
+int rdonly_map_prog(const void *ctx)
+{
+       if (done1)
+               return 0;
+
+       done1 = 1;
+       /* val1/val2 readonly map */
+       if (val1 == val2)
+               ret1 = 1;
+       return 0;
+
+}
+
+SEC("?raw_tp/sys_enter")
+int map_val_prog(const void *ctx)
+{
+       if (done2)
+               return 0;
+
+       done2 = 1;
+       /* val1/val2 regular read/write map */
+       if (val3 == val4)
+               ret2 = 1;
+       return 0;
+
+}
+
+struct bpf_testmod_struct_arg_1 {
+       int a;
+};
+
+long long int_member;
+
+SEC("?fentry/bpf_testmod_test_arg_ptr_to_struct")
+int BPF_PROG2(test_ptr_struct_arg, struct bpf_testmod_struct_arg_1 *, p)
+{
+       /* probed memory access */
+       int_member = p->a;
+        return 0;
+}
+
+long long set_optlen, set_retval;
+
+SEC("?cgroup/getsockopt")
+int _getsockopt(volatile struct bpf_sockopt *ctx)
+{
+       int old_optlen, old_retval;
+
+       old_optlen = ctx->optlen;
+       old_retval = ctx->retval;
+
+       ctx->optlen = -1;
+       ctx->retval = -1;
+
+       /* sign extension for ctx member */
+       set_optlen = ctx->optlen;
+       set_retval = ctx->retval;
+
+       ctx->optlen = old_optlen;
+       ctx->retval = old_retval;
+
+       return 0;
+}
+
+long long set_mark;
+
+SEC("?tc")
+int _tc(volatile struct __sk_buff *skb)
+{
+       long long tmp_mark;
+       int old_mark;
+
+       old_mark = skb->mark;
+
+       skb->mark = 0xf6fe;
+
+       /* narrowed sign extension for ctx member */
+#if __clang_major__ >= 18
+       /* force narrow one-byte signed load. Otherwise, compiler may
+        * generate a 32-bit unsigned load followed by an s8 movsx.
+        */
+       asm volatile ("r1 = *(s8 *)(%[ctx] + %[off_mark])\n\t"
+                     "%[tmp_mark] = r1"
+                     : [tmp_mark]"=r"(tmp_mark)
+                     : [ctx]"r"(skb),
+                       [off_mark]"i"(offsetof(struct __sk_buff, mark))
+                     : "r1");
+#else
+       tmp_mark = (char)skb->mark;
+#endif
+       set_mark = tmp_mark;
+
+       skb->mark = old_mark;
+
+       return 0;
+}
+
+char _license[] SEC("license") = "GPL";