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authorYonghong Song <yhs@fb.com>2022-01-27 18:46:16 +0300
committerAlexei Starovoitov <ast@kernel.org>2022-01-27 23:03:46 +0300
commit696c39011538fe0124fcc0e81ebc44ff7f8623b4 (patch)
treea061e9454b0e33887b6c49aee00cd758a33f706b
parent571d01a9d06f984ce51bd7625036e67f7f1f886c (diff)
downloadlinux-696c39011538fe0124fcc0e81ebc44ff7f8623b4.tar.xz
selftests/bpf: add a selftest with __user tag
Added a selftest with three__user usages: a __user pointer-type argument in bpf_testmod, a __user pointer-type struct member in bpf_testmod, and a __user pointer-type struct member in vmlinux. In all cases, directly accessing the user memory will result verification failure. $ ./test_progs -v -n 22/3 ... libbpf: prog 'test_user1': BPF program load failed: Permission denied libbpf: prog 'test_user1': -- BEGIN PROG LOAD LOG -- R1 type=ctx expected=fp 0: R1=ctx(id=0,off=0,imm=0) R10=fp0 ; 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 136561 type STRUCT 'bpf_testmod_btf_type_tag_1' 1: R1_w=user_ptr_bpf_testmod_btf_type_tag_1(id=0,off=0,imm=0) ; g = arg->a; 1: (61) r1 = *(u32 *)(r1 +0) R1 invalid mem access 'user_ptr_' ... #22/3 btf_tag/btf_type_tag_user_mod1:OK $ ./test_progs -v -n 22/4 ... libbpf: prog 'test_user2': BPF program load failed: Permission denied libbpf: prog 'test_user2': -- BEGIN PROG LOAD LOG -- R1 type=ctx expected=fp 0: R1=ctx(id=0,off=0,imm=0) R10=fp0 ; 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 136563 type STRUCT 'bpf_testmod_btf_type_tag_2' 1: R1_w=ptr_bpf_testmod_btf_type_tag_2(id=0,off=0,imm=0) ; g = arg->p->a; 1: (79) r1 = *(u64 *)(r1 +0) ; R1_w=user_ptr_bpf_testmod_btf_type_tag_1(id=0,off=0,imm=0) ; g = arg->p->a; 2: (61) r1 = *(u32 *)(r1 +0) R1 invalid mem access 'user_ptr_' ... #22/4 btf_tag/btf_type_tag_user_mod2:OK $ ./test_progs -v -n 22/5 ... libbpf: prog 'test_sys_getsockname': BPF program load failed: Permission denied libbpf: prog 'test_sys_getsockname': -- BEGIN PROG LOAD LOG -- R1 type=ctx expected=fp 0: R1=ctx(id=0,off=0,imm=0) R10=fp0 ; int BPF_PROG(test_sys_getsockname, int fd, struct sockaddr *usockaddr, 0: (79) r1 = *(u64 *)(r1 +8) func '__sys_getsockname' arg1 has btf_id 2319 type STRUCT 'sockaddr' 1: R1_w=user_ptr_sockaddr(id=0,off=0,imm=0) ; g = usockaddr->sa_family; 1: (69) r1 = *(u16 *)(r1 +0) R1 invalid mem access 'user_ptr_' ... #22/5 btf_tag/btf_type_tag_user_vmlinux:OK Signed-off-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/r/20220127154616.659314-1-yhs@fb.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
-rw-r--r--tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c18
-rw-r--r--tools/testing/selftests/bpf/prog_tests/btf_tag.c93
-rw-r--r--tools/testing/selftests/bpf/progs/btf_type_tag_user.c40
3 files changed, 151 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c
index bdbacf5adcd2..595d32ab285a 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..f7560b54a6bb 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 +43,101 @@ static void test_btf_type_tag(void)
btf_type_tag__destroy(skel);
}
+static void test_btf_type_tag_mod_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 if 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;
+
+ bpf_program__set_autoload(skel->progs.test_sys_getsockname, false);
+ 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);
+}
+
+static void test_btf_type_tag_vmlinux_user(void)
+{
+ struct btf_type_tag_user *skel;
+ struct btf *vmlinux_btf;
+ __s32 type_id;
+ int err;
+
+ /* skip the test if the vmlinux does not have __user tags */
+ vmlinux_btf = btf__load_vmlinux_btf();
+ if (!ASSERT_OK_PTR(vmlinux_btf, "could not load vmlinux BTF"))
+ return;
+
+ type_id = btf__find_by_name_kind(vmlinux_btf, "user", BTF_KIND_TYPE_TAG);
+ if (type_id <= 0) {
+ printf("%s:SKIP: btf_type_tag attribute not in vmlinux btf", __func__);
+ test__skip();
+ goto free_vmlinux_btf;
+ }
+
+ skel = btf_type_tag_user__open();
+ if (!ASSERT_OK_PTR(skel, "btf_type_tag_user"))
+ goto free_vmlinux_btf;
+
+ bpf_program__set_autoload(skel->progs.test_user2, false);
+ 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_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_mod1"))
+ test_btf_type_tag_mod_user(true);
+ if (test__start_subtest("btf_type_tag_user_mod2"))
+ test_btf_type_tag_mod_user(false);
+ if (test__start_subtest("btf_type_tag_sys_user_vmlinux"))
+ test_btf_type_tag_vmlinux_user();
}
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..5523f77c5a44
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/btf_type_tag_user.c
@@ -0,0 +1,40 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2022 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;
+}
+
+/* int __sys_getsockname(int fd, struct sockaddr __user *usockaddr,
+ * int __user *usockaddr_len);
+ */
+SEC("fentry/__sys_getsockname")
+int BPF_PROG(test_sys_getsockname, int fd, struct sockaddr *usockaddr,
+ int *usockaddr_len)
+{
+ g = usockaddr->sa_family;
+ return 0;
+}