Added a selftest with two __user usages: a __user pointer-type argument
and a __user pointer-type struct member. In both cases,
directly accessing the user memory will result verification failure.
$ ./test_progs -v -n 22/3
...
libbpf: load bpf program failed: Permission denied
libbpf: -- BEGIN DUMP LOG ---
libbpf:
R1 type=ctx expected=fp
; int BPF_PROG(test_user1, struct bpf_testmod_btf_type_tag_1 *arg)
0: (79) r1 = *(u64 *)(r1 +0)
func 'bpf_testmod_test_btf_type_tag_user_1' arg0 has btf_id 143948 addr_space 1 type STRUCT 'bpf_testmod_btf_type_tag_1'
; g = arg->a;
1: (61) r1 = *(u32 *)(r1 +0)
R1 is ptr_bpf_testmod_btf_type_tag_1 access user memory: off=0
...
#22/3 btf_tag/btf_type_tag_user_1:OK
$ ./test_progs -v -n 22/4
...
libbpf: load bpf program failed: Permission denied
libbpf: -- BEGIN DUMP LOG ---
libbpf:
R1 type=ctx expected=fp
; int BPF_PROG(test_user2, struct bpf_testmod_btf_type_tag_2 *arg)
0: (79) r1 = *(u64 *)(r1 +0)
func 'bpf_testmod_test_btf_type_tag_user_2' arg0 has btf_id 143950 addr_space 0 type STRUCT 'bpf_testmod_btf_type_tag_2'
; g = arg->p->a;
1: (79) r1 = *(u64 *)(r1 +0)
; g = arg->p->a;
2: (61) r1 = *(u32 *)(r1 +0)
R1 is ptr_bpf_testmod_btf_type_tag_1 access user memory: off=0
...
#22/4 btf_tag/btf_type_tag_user_2:OK
Signed-off-by: Yonghong Song <yhs@xxxxxx>
---
.../selftests/bpf/bpf_testmod/bpf_testmod.c | 18 ++++++
.../selftests/bpf/prog_tests/btf_tag.c | 55 +++++++++++++++++++
.../selftests/bpf/progs/btf_type_tag_user.c | 29 ++++++++++
3 files changed, 102 insertions(+)
create mode 100644 tools/testing/selftests/bpf/progs/btf_type_tag_user.c
diff --git a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c
index 5d52ea2768df..119fd5ba7ce4 100644
--- a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c
+++ b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c
@@ -21,6 +21,24 @@ bpf_testmod_test_mod_kfunc(int i)
*(int *)this_cpu_ptr(&bpf_testmod_ksym_percpu) = i;
}
+struct bpf_testmod_btf_type_tag_1 {
+ int a;
+};
+
+struct bpf_testmod_btf_type_tag_2 {
+ struct bpf_testmod_btf_type_tag_1 __user *p;
+};
+
+noinline int
+bpf_testmod_test_btf_type_tag_user_1(struct bpf_testmod_btf_type_tag_1 __user *arg) {
+ return arg->a;
+}
+
+noinline int
+bpf_testmod_test_btf_type_tag_user_2(struct bpf_testmod_btf_type_tag_2 *arg) {
+ return arg->p->a;
+}
+
noinline int bpf_testmod_loop_test(int n)
{
int i, sum = 0;
diff --git a/tools/testing/selftests/bpf/prog_tests/btf_tag.c b/tools/testing/selftests/bpf/prog_tests/btf_tag.c
index c4cf27777ff7..794752265ede 100644
--- a/tools/testing/selftests/bpf/prog_tests/btf_tag.c
+++ b/tools/testing/selftests/bpf/prog_tests/btf_tag.c
@@ -1,6 +1,7 @@
// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2021 Facebook */
#include <test_progs.h>
+#include <bpf/btf.h>
#include "test_btf_decl_tag.skel.h"
/* struct btf_type_tag_test is referenced in btf_type_tag.skel.h */
@@ -8,6 +9,7 @@ struct btf_type_tag_test {
int **p;
};
#include "btf_type_tag.skel.h"
+#include "btf_type_tag_user.skel.h"
static void test_btf_decl_tag(void)
{
@@ -41,10 +43,63 @@ static void test_btf_type_tag(void)
btf_type_tag__destroy(skel);
}
+static void test_btf_type_tag_user(bool load_test_user1)
+{
+ const char *module_name = "bpf_testmod";
+ struct btf *vmlinux_btf, *module_btf;
+ struct btf_type_tag_user *skel;
+ __s32 type_id;
+ int err;
+
+ if (!env.has_testmod) {
+ test__skip();
+ return;
+ }
+
+ /* skip the test is the module does not have __user tags */
+ vmlinux_btf = btf__load_vmlinux_btf();
+ if (!ASSERT_OK_PTR(vmlinux_btf, "could not load vmlinux BTF"))
+ return;
+
+ module_btf = btf__load_module_btf(module_name, vmlinux_btf);
+ if (!ASSERT_OK_PTR(module_btf, "could not load module BTF"))
+ goto free_vmlinux_btf;
+
+ type_id = btf__find_by_name_kind(module_btf, "user", BTF_KIND_TYPE_TAG);
+ if (type_id <= 0) {
+ printf("%s:SKIP: btf_type_tag attribute not in %s", __func__, module_name);
+ test__skip();
+ goto free_module_btf;
+ }
+
+ skel = btf_type_tag_user__open();
+ if (!ASSERT_OK_PTR(skel, "btf_type_tag_user"))
+ goto free_module_btf;
+
+ if (load_test_user1)
+ bpf_program__set_autoload(skel->progs.test_user2, false);
+ else
+ bpf_program__set_autoload(skel->progs.test_user1, false);
+
+ err = btf_type_tag_user__load(skel);
+ ASSERT_ERR(err, "btf_type_tag_user");
+
+ btf_type_tag_user__destroy(skel);
+
+free_module_btf:
+ btf__free(module_btf);
+free_vmlinux_btf:
+ btf__free(vmlinux_btf);
+}
+
void test_btf_tag(void)
{
if (test__start_subtest("btf_decl_tag"))
test_btf_decl_tag();
if (test__start_subtest("btf_type_tag"))
test_btf_type_tag();
+ if (test__start_subtest("btf_type_tag_user_1"))
+ test_btf_type_tag_user(true);
+ if (test__start_subtest("btf_type_tag_user_2"))
+ test_btf_type_tag_user(false);
}
diff --git a/tools/testing/selftests/bpf/progs/btf_type_tag_user.c b/tools/testing/selftests/bpf/progs/btf_type_tag_user.c
new file mode 100644
index 000000000000..e149854f42dd
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/btf_type_tag_user.c
@@ -0,0 +1,29 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2021 Facebook */
+#include "vmlinux.h"
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+
+struct bpf_testmod_btf_type_tag_1 {
+ int a;
+};
+
+struct bpf_testmod_btf_type_tag_2 {
+ struct bpf_testmod_btf_type_tag_1 *p;
+};
+
+int g;
+
+SEC("fentry/bpf_testmod_test_btf_type_tag_user_1")
+int BPF_PROG(test_user1, struct bpf_testmod_btf_type_tag_1 *arg)
+{
+ g = arg->a;
+ return 0;
+}
+
+SEC("fentry/bpf_testmod_test_btf_type_tag_user_2")
+int BPF_PROG(test_user2, struct bpf_testmod_btf_type_tag_2 *arg)
+{
+ g = arg->p->a;
+ return 0;
+}
--
2.30.2
