Re: [PATCH bpf-next v6 2/5] selftests/bpf: Add tests for open-coded style process file iterator

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 






On 12/17/24 3:37 PM, Juntong Deng wrote:
This patch adds test cases for open-coded style process file iterator.

Test cases related to process files are run in the newly created child
process. Close all opened files inherited from the parent process in
the child process to avoid the files opened by the parent process
affecting the test results.

In addition, this patch adds failure test cases where bpf programs
cannot pass the verifier due to uninitialized or untrusted
arguments, etc.

Signed-off-by: Juntong Deng <juntong.deng@xxxxxxxxxxx>
---
  .../testing/selftests/bpf/bpf_experimental.h  |  7 ++
  .../testing/selftests/bpf/prog_tests/iters.c  | 79 ++++++++++++++++
  .../selftests/bpf/progs/iters_task_file.c     | 86 ++++++++++++++++++
  .../bpf/progs/iters_task_file_failure.c       | 91 +++++++++++++++++++
  4 files changed, 263 insertions(+)
  create mode 100644 tools/testing/selftests/bpf/progs/iters_task_file.c
  create mode 100644 tools/testing/selftests/bpf/progs/iters_task_file_failure.c

diff --git a/tools/testing/selftests/bpf/bpf_experimental.h b/tools/testing/selftests/bpf/bpf_experimental.h
index cd8ecd39c3f3..ce1520c56b55 100644
--- a/tools/testing/selftests/bpf/bpf_experimental.h
+++ b/tools/testing/selftests/bpf/bpf_experimental.h
@@ -588,4 +588,11 @@ extern int bpf_iter_kmem_cache_new(struct bpf_iter_kmem_cache *it) __weak __ksym
  extern struct kmem_cache *bpf_iter_kmem_cache_next(struct bpf_iter_kmem_cache *it) __weak __ksym;
  extern void bpf_iter_kmem_cache_destroy(struct bpf_iter_kmem_cache *it) __weak __ksym;
+struct bpf_iter_task_file;
+struct bpf_iter_task_file_item;
+extern int bpf_iter_task_file_new(struct bpf_iter_task_file *it, struct task_struct *task) __ksym;
+extern struct bpf_iter_task_file_item *
+bpf_iter_task_file_next(struct bpf_iter_task_file *it) __ksym;
+extern void bpf_iter_task_file_destroy(struct bpf_iter_task_file *it) __ksym;

All the above declarations should be in vmlinux.h already and I see your below bpf prog already
included vmlinux.h, there is no need to put them here.

+
  #endif
diff --git a/tools/testing/selftests/bpf/prog_tests/iters.c b/tools/testing/selftests/bpf/prog_tests/iters.c
index 3cea71f9c500..cfe5b56cc027 100644
--- a/tools/testing/selftests/bpf/prog_tests/iters.c
+++ b/tools/testing/selftests/bpf/prog_tests/iters.c
@@ -1,6 +1,8 @@
  // SPDX-License-Identifier: GPL-2.0
  /* Copyright (c) 2023 Meta Platforms, Inc. and affiliates. */
+#define _GNU_SOURCE
+#include <sys/socket.h>
  #include <sys/syscall.h>
  #include <sys/mman.h>
  #include <sys/wait.h>
@@ -16,11 +18,13 @@
  #include "iters_num.skel.h"
  #include "iters_testmod.skel.h"
  #include "iters_testmod_seq.skel.h"
+#include "iters_task_file.skel.h"
  #include "iters_task_vma.skel.h"
  #include "iters_task.skel.h"
  #include "iters_css_task.skel.h"
  #include "iters_css.skel.h"
  #include "iters_task_failure.skel.h"
+#include "iters_task_file_failure.skel.h"
static void subtest_num_iters(void)
  {
@@ -291,6 +295,78 @@ static void subtest_css_iters(void)
  	iters_css__destroy(skel);
  }
+static int task_file_test_process(void *args)
+{
+	int pipefd[2], sockfd, err = 0;
+
+	/* Create a clean file descriptor table for the test process */
+	close_range(0, ~0U, 0);
+
+	if (pipe(pipefd) < 0)
+		return 1;
+
+	sockfd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
+	if (sockfd < 0) {
+		err = 2;
+		goto cleanup_pipe;
+	}
+
+	usleep(1);
+
+	close(sockfd);
+cleanup_pipe:
+	close(pipefd[0]);
+	close(pipefd[1]);
+	return err;
+}
+
+static void subtest_task_file_iters(void)
+{
+	const int stack_size = 1024 * 1024;
+	struct iters_task_file *skel;
+	int child_pid, wstatus, err;
+	char *stack;
+
+	skel = iters_task_file__open_and_load();
+	if (!ASSERT_OK_PTR(skel, "open_and_load"))
+		return;
+
+	if (!ASSERT_OK(skel->bss->err, "pre_test_err"))
+		goto cleanup_skel;
+
+	skel->bss->parent_pid = getpid();
+	skel->bss->count = 0;
+
+	err = iters_task_file__attach(skel);
+	if (!ASSERT_OK(err, "skel_attach"))
+		goto cleanup_skel;
+
+	stack = (char *)malloc(stack_size);
+	if (!ASSERT_OK_PTR(stack, "clone_stack"))
+		goto cleanup_attach;
+
+	/* Note that there is no CLONE_FILES */
+	child_pid = clone(task_file_test_process, stack + stack_size, CLONE_VM | SIGCHLD, NULL);
+	if (!ASSERT_GT(child_pid, -1, "child_pid"))
+		goto cleanup_stack;
+
+	if (!ASSERT_GT(waitpid(child_pid, &wstatus, 0), -1, "waitpid"))
+		goto cleanup_stack;
+
+	if (!ASSERT_OK(WEXITSTATUS(wstatus), "run_task_file_iters_test_err"))
+		goto cleanup_stack;
+
+	ASSERT_EQ(skel->bss->count, 1, "run_task_file_iters_test_count_err");
+	ASSERT_OK(skel->bss->err, "run_task_file_iters_test_failure");
+
+cleanup_stack:
+	free(stack);
+cleanup_attach:
+	iters_task_file__detach(skel);
+cleanup_skel:
+	iters_task_file__destroy(skel);
+}
+
  void test_iters(void)
  {
  	RUN_TESTS(iters_state_safety);
@@ -315,5 +391,8 @@ void test_iters(void)
  		subtest_css_task_iters();
  	if (test__start_subtest("css"))
  		subtest_css_iters();
+	if (test__start_subtest("task_file"))
+		subtest_task_file_iters();
  	RUN_TESTS(iters_task_failure);
+	RUN_TESTS(iters_task_file_failure);
  }
diff --git a/tools/testing/selftests/bpf/progs/iters_task_file.c b/tools/testing/selftests/bpf/progs/iters_task_file.c
new file mode 100644
index 000000000000..47941530e51b
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/iters_task_file.c
@@ -0,0 +1,86 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include "vmlinux.h"
+#include <bpf/bpf_tracing.h>
+#include <bpf/bpf_helpers.h>
+#include "bpf_misc.h"
+#include "bpf_experimental.h"
+#include "task_kfunc_common.h"
+
+char _license[] SEC("license") = "GPL";
+
+int err, parent_pid, count;
+
+extern const void pipefifo_fops __ksym;
+extern const void socket_file_ops __ksym;

There is no need to have 'const' in the above two extern declarations.

+
+SEC("fentry/" SYS_PREFIX "sys_nanosleep")
+int test_bpf_iter_task_file(void *ctx)
+{
+	struct bpf_iter_task_file task_file_it;
+	struct bpf_iter_task_file_item *item;
+	struct task_struct *task;
+
+	task = bpf_get_current_task_btf();
+	if (task->parent->pid != parent_pid)
+		return 0;
+
+	count++;
+
+	bpf_iter_task_file_new(&task_file_it, task);
+
+	item = bpf_iter_task_file_next(&task_file_it);
+	if (item == NULL) {
+		err = 1;
+		goto cleanup;
+	}
+
+	if (item->fd != 0) {
+		err = 2;
+		goto cleanup;
+	}
+
+	if (item->file->f_op != &pipefifo_fops) {
+		err = 3;
+		goto cleanup;
+	}
+
+	item = bpf_iter_task_file_next(&task_file_it);
+	if (item == NULL) {
+		err = 4;
+		goto cleanup;
+	}
+
+	if (item->fd != 1) {
+		err = 5;
+		goto cleanup;
+	}
+
+	if (item->file->f_op != &pipefifo_fops) {
+		err = 6;
+		goto cleanup;
+	}
+
+	item = bpf_iter_task_file_next(&task_file_it);
+	if (item == NULL) {
+		err = 7;
+		goto cleanup;
+	}
+
+	if (item->fd != 2) {
+		err = 8;
+		goto cleanup;
+	}
+
+	if (item->file->f_op != &socket_file_ops) {
+		err = 9;
+		goto cleanup;
+	}
+
+	item = bpf_iter_task_file_next(&task_file_it);
+	if (item != NULL)
+		err = 10;
+cleanup:
+	bpf_iter_task_file_destroy(&task_file_it);
+	return 0;
+}

[...]





[Index of Archives]     [Linux Ext4 Filesystem]     [Union Filesystem]     [Filesystem Testing]     [Ceph Users]     [Ecryptfs]     [NTFS 3]     [AutoFS]     [Kernel Newbies]     [Share Photos]     [Security]     [Netfilter]     [Bugtraq]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux Cachefs]     [Reiser Filesystem]     [Linux RAID]     [NTFS 3]     [Samba]     [Device Mapper]     [CEPH Development]

  Powered by Linux