From: Hou Tao <houtao1@xxxxxxxxxx>
The test uses bpf_prog_get_info_by_fd() to obtain the xlated
instructions of the program first. Since these instructions have
already been rewritten by the verifier, the tests then checks whether
the rewritten instructions are as expected.
Signed-off-by: Hou Tao <houtao1@xxxxxxxxxx>
---
.../bpf/prog_tests/kptr_xchg_inline.c | 51 +++++++++++++++++++
.../selftests/bpf/progs/kptr_xchg_inline.c | 28 ++++++++++
2 files changed, 79 insertions(+)
create mode 100644 tools/testing/selftests/bpf/prog_tests/kptr_xchg_inline.c
create mode 100644 tools/testing/selftests/bpf/progs/kptr_xchg_inline.c
diff --git a/tools/testing/selftests/bpf/prog_tests/kptr_xchg_inline.c b/tools/testing/selftests/bpf/prog_tests/kptr_xchg_inline.c
new file mode 100644
index 000000000000..5a4bee1cf970
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/kptr_xchg_inline.c
@@ -0,0 +1,51 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (C) 2023. Huawei Technologies Co., Ltd */
+#include <test_progs.h>
+
+#include "linux/filter.h"
+#include "kptr_xchg_inline.skel.h"
+
+void test_kptr_xchg_inline(void)
+{
+ struct kptr_xchg_inline *skel;
+ struct bpf_insn *insn = NULL;
+ struct bpf_insn exp;
+ unsigned int cnt;
+ int err;
+
+#if !defined(__x86_64__)
+ test__skip();
+ return;
+#endif
+
+ skel = kptr_xchg_inline__open_and_load();
+ if (!ASSERT_OK_PTR(skel, "open_load"))
+ return;
+
+ err = get_xlated_program(bpf_program__fd(skel->progs.kptr_xchg_inline), &insn, &cnt);
+ if (!ASSERT_OK(err, "prog insn"))
+ goto out;
+
+ /* The original instructions are:
+ * r1 = map[id:xxx][0]+0
+ * r2 = 0
+ * call bpf_kptr_xchg#yyy
+ *
+ * call bpf_kptr_xchg#yyy will be inlined as:
+ * r0 = r2
+ * r0 = atomic64_xchg((u64 *)(r1 +0), r0)
+ */
+ if (!ASSERT_GT(cnt, 5, "insn cnt"))
+ goto out;
+
+ exp = BPF_MOV64_REG(BPF_REG_0, BPF_REG_2);
+ if (!ASSERT_OK(memcmp(&insn[3], &exp, sizeof(exp)), "mov"))
+ goto out;
+
+ exp = BPF_ATOMIC_OP(BPF_DW, BPF_XCHG, BPF_REG_1, BPF_REG_0, 0);
+ if (!ASSERT_OK(memcmp(&insn[4], &exp, sizeof(exp)), "xchg"))
+ goto out;
+out:
+ free(insn);
+ kptr_xchg_inline__destroy(skel);
+}
diff --git a/tools/testing/selftests/bpf/progs/kptr_xchg_inline.c b/tools/testing/selftests/bpf/progs/kptr_xchg_inline.c
new file mode 100644
index 000000000000..1db7909828d1
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/kptr_xchg_inline.c
@@ -0,0 +1,28 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (C) 2023. Huawei Technologies Co., Ltd */
+#include <linux/types.h>
+#include <bpf/bpf_helpers.h>
+
+#include "bpf_experimental.h"
+#include "bpf_misc.h"
+
+char _license[] SEC("license") = "GPL";
+
+struct bin_data {
+ char blob[32];
+};
+
+#define private(name) SEC(".bss." #name) __hidden __attribute__((aligned(8)))
+private(kptr) struct bin_data __kptr * ptr;
+
+SEC("tc")
+int kptr_xchg_inline(void *ctx)
+{
+ void *old;
+
+ old = bpf_kptr_xchg(&ptr, NULL);
+ if (old)
+ bpf_obj_drop(old);
+
+ return 0;
+}
--
2.29.2
