[RFC PATCH -mm 4/4] selftests/bpf: Add selftests for mbind(2) with lsm prog
Yafang Shao
laoar.shao at gmail.com
Sun Nov 12 07:34:24 UTC 2023
The result as follows,
#142/1 mempolicy/MPOL_BIND_with_lsm:OK
#142/2 mempolicy/MPOL_DEFAULT_with_lsm:OK
#142/3 mempolicy/MPOL_BIND_without_lsm:OK
#142/4 mempolicy/MPOL_DEFAULT_without_lsm:OK
#142 mempolicy:OK
Signed-off-by: Yafang Shao <laoar.shao at gmail.com>
---
tools/testing/selftests/bpf/prog_tests/mempolicy.c | 79 ++++++++++++++++++++++
tools/testing/selftests/bpf/progs/test_mempolicy.c | 29 ++++++++
2 files changed, 108 insertions(+)
create mode 100644 tools/testing/selftests/bpf/prog_tests/mempolicy.c
create mode 100644 tools/testing/selftests/bpf/progs/test_mempolicy.c
diff --git a/tools/testing/selftests/bpf/prog_tests/mempolicy.c b/tools/testing/selftests/bpf/prog_tests/mempolicy.c
new file mode 100644
index 0000000..e0dfb18
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/mempolicy.c
@@ -0,0 +1,79 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (C) 2023 Yafang Shao <laoar.shao at gmail.com> */
+
+#include <sys/types.h>
+#include <unistd.h>
+#include <sys/mman.h>
+#include <numaif.h>
+#include <test_progs.h>
+#include "test_mempolicy.skel.h"
+
+#define SIZE 4096
+
+static void mempolicy_bind(bool success)
+{
+ unsigned long mask = 1;
+ char *addr;
+ int err;
+
+ addr = mmap(NULL, SIZE, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
+ if (!ASSERT_OK_PTR(addr, "mmap"))
+ return;
+
+ err = mbind(addr, SIZE, MPOL_BIND, &mask, sizeof(mask), 0);
+ if (success)
+ ASSERT_OK(err, "mbind_success");
+ else
+ ASSERT_ERR(err, "mbind_fail");
+
+ munmap(addr, SIZE);
+}
+
+static void mempolicy_default(void)
+{
+ char *addr;
+ int err;
+
+ addr = mmap(NULL, SIZE, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
+ if (!ASSERT_OK_PTR(addr, "mmap"))
+ return;
+
+ err = mbind(addr, SIZE, MPOL_DEFAULT, NULL, 0, 0);
+ ASSERT_OK(err, "mbind_success");
+
+ munmap(addr, SIZE);
+}
+void test_mempolicy(void)
+{
+ struct test_mempolicy *skel;
+ int err;
+
+ skel = test_mempolicy__open();
+ if (!ASSERT_OK_PTR(skel, "open"))
+ return;
+
+ skel->bss->target_pid = getpid();
+
+ err = test_mempolicy__load(skel);
+ if (!ASSERT_OK(err, "load"))
+ goto destroy;
+
+ /* Attach LSM prog first */
+ err = test_mempolicy__attach(skel);
+ if (!ASSERT_OK(err, "attach"))
+ goto destroy;
+
+ /* syscall to adjust memory policy */
+ if (test__start_subtest("MPOL_BIND_with_lsm"))
+ mempolicy_bind(false);
+ if (test__start_subtest("MPOL_DEFAULT_with_lsm"))
+ mempolicy_default();
+
+destroy:
+ test_mempolicy__destroy(skel);
+
+ if (test__start_subtest("MPOL_BIND_without_lsm"))
+ mempolicy_bind(true);
+ if (test__start_subtest("MPOL_DEFAULT_without_lsm"))
+ mempolicy_default();
+}
diff --git a/tools/testing/selftests/bpf/progs/test_mempolicy.c b/tools/testing/selftests/bpf/progs/test_mempolicy.c
new file mode 100644
index 0000000..2fe8c99
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/test_mempolicy.c
@@ -0,0 +1,29 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (C) 2023 Yafang Shao <laoar.shao at gmail.com> */
+
+#include "vmlinux.h"
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+#include <bpf/bpf_core_read.h>
+
+int target_pid;
+
+static int mem_policy_adjustment(u64 mode)
+{
+ struct task_struct *task = bpf_get_current_task_btf();
+
+ if (task->pid != target_pid)
+ return 0;
+
+ if (mode != MPOL_BIND)
+ return 0;
+ return -1;
+}
+
+SEC("lsm/mbind")
+int BPF_PROG(mbind_run, u64 start, u64 len, u64 mode, const u64 *nmask, u64 maxnode, u32 flags)
+{
+ return mem_policy_adjustment(mode);
+}
+
+char _license[] SEC("license") = "GPL";
--
1.8.3.1
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