From: Hao Luo <haoluo@google.com>
Date: Fri, 4 Mar 2022 11:16:57 -0800
Subject: selftests/bpf: Add a test for btf_type_tag "percpu"
Patch-mainline: v5.18-rc1
Git-commit: 50c6b8a9aea2b8dc6c4ffb0cc502b94f7f57a0dc
References: jsc#PED-1377
Add test for percpu btf_type_tag. Similar to the "user" tag, we test
the following cases:
1. __percpu struct field.
2. __percpu as function parameter.
3. per_cpu_ptr() accepts dynamically allocated __percpu memory.
Because the test for "user" and the test for "percpu" are very similar,
a little bit of refactoring has been done in btf_tag.c. Basically, both
tests share the same function for loading vmlinux and module btf.
Example output from log:
> ./test_progs -v -t btf_tag
libbpf: prog 'test_percpu1': BPF program load failed: Permission denied
libbpf: prog 'test_percpu1': -- BEGIN PROG LOAD LOG --
...
; g = arg->a;
1: (61) r1 = *(u32 *)(r1 +0)
R1 is ptr_bpf_testmod_btf_type_tag_1 access percpu memory: off=0
...
test_btf_type_tag_mod_percpu:PASS:btf_type_tag_percpu 0 nsec
#26/6 btf_tag/btf_type_tag_percpu_mod1:OK
libbpf: prog 'test_percpu2': BPF program load failed: Permission denied
libbpf: prog 'test_percpu2': -- BEGIN PROG LOAD LOG --
...
; g = arg->p->a;
2: (61) r1 = *(u32 *)(r1 +0)
R1 is ptr_bpf_testmod_btf_type_tag_1 access percpu memory: off=0
...
test_btf_type_tag_mod_percpu:PASS:btf_type_tag_percpu 0 nsec
#26/7 btf_tag/btf_type_tag_percpu_mod2:OK
libbpf: prog 'test_percpu_load': BPF program load failed: Permission denied
libbpf: prog 'test_percpu_load': -- BEGIN PROG LOAD LOG --
...
; g = (__u64)cgrp->rstat_cpu->updated_children;
2: (79) r1 = *(u64 *)(r1 +48)
R1 is ptr_cgroup_rstat_cpu access percpu memory: off=48
...
test_btf_type_tag_vmlinux_percpu:PASS:btf_type_tag_percpu_load 0 nsec
#26/8 btf_tag/btf_type_tag_percpu_vmlinux_load:OK
load_btfs:PASS:could not load vmlinux BTF 0 nsec
test_btf_type_tag_vmlinux_percpu:PASS:btf_type_tag_percpu 0 nsec
test_btf_type_tag_vmlinux_percpu:PASS:btf_type_tag_percpu_helper 0 nsec
#26/9 btf_tag/btf_type_tag_percpu_vmlinux_helper:OK
Signed-off-by: Hao Luo <haoluo@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20220304191657.981240-5-haoluo@google.com
Acked-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
---
tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c | 14 +
tools/testing/selftests/bpf/prog_tests/btf_tag.c | 164 +++++++++++++---
tools/testing/selftests/bpf/progs/btf_type_tag_percpu.c | 66 ++++++
3 files changed, 215 insertions(+), 29 deletions(-)
create mode 100644 tools/testing/selftests/bpf/progs/btf_type_tag_percpu.c
--- a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c
+++ b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c
@@ -33,6 +33,10 @@ struct bpf_testmod_btf_type_tag_2 {
struct bpf_testmod_btf_type_tag_1 __user *p;
};
+struct bpf_testmod_btf_type_tag_3 {
+ struct bpf_testmod_btf_type_tag_1 __percpu *p;
+};
+
noinline int
bpf_testmod_test_btf_type_tag_user_1(struct bpf_testmod_btf_type_tag_1 __user *arg) {
BTF_TYPE_EMIT(func_proto_typedef);
@@ -46,6 +50,16 @@ bpf_testmod_test_btf_type_tag_user_2(str
return arg->p->a;
}
+noinline int
+bpf_testmod_test_btf_type_tag_percpu_1(struct bpf_testmod_btf_type_tag_1 __percpu *arg) {
+ return arg->a;
+}
+
+noinline int
+bpf_testmod_test_btf_type_tag_percpu_2(struct bpf_testmod_btf_type_tag_3 *arg) {
+ return arg->p->a;
+}
+
noinline int bpf_testmod_loop_test(int n)
{
int i, sum = 0;
--- a/tools/testing/selftests/bpf/prog_tests/btf_tag.c
+++ b/tools/testing/selftests/bpf/prog_tests/btf_tag.c
@@ -10,6 +10,7 @@ struct btf_type_tag_test {
};
#include "btf_type_tag.skel.h"
#include "btf_type_tag_user.skel.h"
+#include "btf_type_tag_percpu.skel.h"
static void test_btf_decl_tag(void)
{
@@ -43,38 +44,81 @@ static void test_btf_type_tag(void)
btf_type_tag__destroy(skel);
}
-static void test_btf_type_tag_mod_user(bool load_test_user1)
+/* loads vmlinux_btf as well as module_btf. If the caller passes NULL as
+ * module_btf, it will not load module btf.
+ *
+ * Returns 0 on success.
+ * Return -1 On error. In case of error, the loaded btf will be freed and the
+ * input parameters will be set to pointing to NULL.
+ */
+static int load_btfs(struct btf **vmlinux_btf, struct btf **module_btf,
+ bool needs_vmlinux_tag)
{
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;
+ return -1;
}
- /* 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;
+ *vmlinux_btf = btf__load_vmlinux_btf();
+ if (!ASSERT_OK_PTR(*vmlinux_btf, "could not load vmlinux BTF"))
+ return -1;
+
+ if (!needs_vmlinux_tag)
+ goto load_module_btf;
+
+ /* skip the test if the vmlinux does not have __user tags */
+ 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;
+ }
+
+load_module_btf:
+ /* skip loading module_btf, if not requested by caller */
+ if (!module_btf)
+ return 0;
- module_btf = btf__load_module_btf(module_name, vmlinux_btf);
- if (!ASSERT_OK_PTR(module_btf, "could not load module BTF"))
+ *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);
+ /* skip the test if the module does not have __user tags */
+ 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;
}
+ return 0;
+
+free_module_btf:
+ btf__free(*module_btf);
+free_vmlinux_btf:
+ btf__free(*vmlinux_btf);
+
+ *vmlinux_btf = NULL;
+ if (module_btf)
+ *module_btf = NULL;
+ return -1;
+}
+
+static void test_btf_type_tag_mod_user(bool load_test_user1)
+{
+ struct btf *vmlinux_btf = NULL, *module_btf = NULL;
+ struct btf_type_tag_user *skel;
+ int err;
+
+ if (load_btfs(&vmlinux_btf, &module_btf, /*needs_vmlinux_tag=*/false))
+ return;
+
skel = btf_type_tag_user__open();
if (!ASSERT_OK_PTR(skel, "btf_type_tag_user"))
- goto free_module_btf;
+ goto cleanup;
bpf_program__set_autoload(skel->progs.test_sys_getsockname, false);
if (load_test_user1)
@@ -87,34 +131,23 @@ static void test_btf_type_tag_mod_user(b
btf_type_tag_user__destroy(skel);
-free_module_btf:
+cleanup:
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;
+ struct btf *vmlinux_btf = NULL;
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"))
+ if (load_btfs(&vmlinux_btf, NULL, /*needs_vmlinux_tag=*/true))
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;
+ goto cleanup;
bpf_program__set_autoload(skel->progs.test_user2, false);
bpf_program__set_autoload(skel->progs.test_user1, false);
@@ -124,7 +157,70 @@ static void test_btf_type_tag_vmlinux_us
btf_type_tag_user__destroy(skel);
-free_vmlinux_btf:
+cleanup:
+ btf__free(vmlinux_btf);
+}
+
+static void test_btf_type_tag_mod_percpu(bool load_test_percpu1)
+{
+ struct btf *vmlinux_btf, *module_btf;
+ struct btf_type_tag_percpu *skel;
+ int err;
+
+ if (load_btfs(&vmlinux_btf, &module_btf, /*needs_vmlinux_tag=*/false))
+ return;
+
+ skel = btf_type_tag_percpu__open();
+ if (!ASSERT_OK_PTR(skel, "btf_type_tag_percpu"))
+ goto cleanup;
+
+ bpf_program__set_autoload(skel->progs.test_percpu_load, false);
+ bpf_program__set_autoload(skel->progs.test_percpu_helper, false);
+ if (load_test_percpu1)
+ bpf_program__set_autoload(skel->progs.test_percpu2, false);
+ else
+ bpf_program__set_autoload(skel->progs.test_percpu1, false);
+
+ err = btf_type_tag_percpu__load(skel);
+ ASSERT_ERR(err, "btf_type_tag_percpu");
+
+ btf_type_tag_percpu__destroy(skel);
+
+cleanup:
+ btf__free(module_btf);
+ btf__free(vmlinux_btf);
+}
+
+static void test_btf_type_tag_vmlinux_percpu(bool load_test)
+{
+ struct btf_type_tag_percpu *skel;
+ struct btf *vmlinux_btf = NULL;
+ int err;
+
+ if (load_btfs(&vmlinux_btf, NULL, /*needs_vmlinux_tag=*/true))
+ return;
+
+ skel = btf_type_tag_percpu__open();
+ if (!ASSERT_OK_PTR(skel, "btf_type_tag_percpu"))
+ goto cleanup;
+
+ bpf_program__set_autoload(skel->progs.test_percpu2, false);
+ bpf_program__set_autoload(skel->progs.test_percpu1, false);
+ if (load_test) {
+ bpf_program__set_autoload(skel->progs.test_percpu_helper, false);
+
+ err = btf_type_tag_percpu__load(skel);
+ ASSERT_ERR(err, "btf_type_tag_percpu_load");
+ } else {
+ bpf_program__set_autoload(skel->progs.test_percpu_load, false);
+
+ err = btf_type_tag_percpu__load(skel);
+ ASSERT_OK(err, "btf_type_tag_percpu_helper");
+ }
+
+ btf_type_tag_percpu__destroy(skel);
+
+cleanup:
btf__free(vmlinux_btf);
}
@@ -134,10 +230,20 @@ void test_btf_tag(void)
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();
+
+ if (test__start_subtest("btf_type_tag_percpu_mod1"))
+ test_btf_type_tag_mod_percpu(true);
+ if (test__start_subtest("btf_type_tag_percpu_mod2"))
+ test_btf_type_tag_mod_percpu(false);
+ if (test__start_subtest("btf_type_tag_percpu_vmlinux_load"))
+ test_btf_type_tag_vmlinux_percpu(true);
+ if (test__start_subtest("btf_type_tag_percpu_vmlinux_helper"))
+ test_btf_type_tag_vmlinux_percpu(false);
}
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/btf_type_tag_percpu.c
@@ -0,0 +1,66 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2022 Google */
+#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;
+};
+
+__u64 g;
+
+SEC("fentry/bpf_testmod_test_btf_type_tag_percpu_1")
+int BPF_PROG(test_percpu1, struct bpf_testmod_btf_type_tag_1 *arg)
+{
+ g = arg->a;
+ return 0;
+}
+
+SEC("fentry/bpf_testmod_test_btf_type_tag_percpu_2")
+int BPF_PROG(test_percpu2, struct bpf_testmod_btf_type_tag_2 *arg)
+{
+ g = arg->p->a;
+ return 0;
+}
+
+/* trace_cgroup_mkdir(struct cgroup *cgrp, const char *path)
+ *
+ * struct cgroup_rstat_cpu {
+ * ...
+ * struct cgroup *updated_children;
+ * ...
+ * };
+ *
+ * struct cgroup {
+ * ...
+ * struct cgroup_rstat_cpu __percpu *rstat_cpu;
+ * ...
+ * };
+ */
+SEC("tp_btf/cgroup_mkdir")
+int BPF_PROG(test_percpu_load, struct cgroup *cgrp, const char *path)
+{
+ g = (__u64)cgrp->rstat_cpu->updated_children;
+ return 0;
+}
+
+SEC("tp_btf/cgroup_mkdir")
+int BPF_PROG(test_percpu_helper, struct cgroup *cgrp, const char *path)
+{
+ struct cgroup_rstat_cpu *rstat;
+ __u32 cpu;
+
+ cpu = bpf_get_smp_processor_id();
+ rstat = (struct cgroup_rstat_cpu *)bpf_per_cpu_ptr(cgrp->rstat_cpu, cpu);
+ if (rstat) {
+ /* READ_ONCE */
+ *(volatile int *)rstat;
+ }
+
+ return 0;
+}