Commit cbf9f849 authored by Martin KaFai Lau's avatar Martin KaFai Lau Committed by Alexei Starovoitov
Browse files

selftests/bpf: Add update_elem failure test for task storage uptr 



This patch test the following failures in syscall update_elem
1. The first update_elem(BPF_F_LOCK) should be EOPNOTSUPP. syscall.c takes
   care of unpinning the uptr.
2. The second update_elem(BPF_EXIST) fails. syscall.c takes care of
   unpinning the uptr.
3. The forth update_elem(BPF_NOEXIST) fails. bpf_local_storage_update
   takes care of unpinning the uptr.

Signed-off-by: default avatarMartin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/r/20241023234759.860539-11-martin.lau@linux.dev


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent 51fff408

tools/testing/selftests/bpf/prog_tests/task_local_storage.c

+45 −0
Original line number Diff line number Diff line
@@ -17,6 +17,7 @@ 
#include "task_storage_nodeadlock.skel.h"

#include "uptr_test_common.h"

#include "task_ls_uptr.skel.h"

#include "uptr_update_failure.skel.h"



static void test_sys_enter_exit(void)

{
@@ -408,6 +409,48 @@ static void test_uptr_across_pages(void) 
	munmap(mem, page_size * 2);

}



static void test_uptr_update_failure(void)

{

	struct value_lock_type value = {};

	struct uptr_update_failure *skel;

	int err, task_fd, map_fd;



	task_fd = sys_pidfd_open(getpid(), 0);

	if (!ASSERT_OK_FD(task_fd, "task_fd"))

		return;



	skel = uptr_update_failure__open_and_load();

	if (!ASSERT_OK_PTR(skel, "skel_open_and_load"))

		goto out;



	map_fd = bpf_map__fd(skel->maps.datamap);



	value.udata = &udata;

	err = bpf_map_update_elem(map_fd, &task_fd, &value, BPF_F_LOCK);

	if (!ASSERT_ERR(err, "update_elem(udata, BPF_F_LOCK)"))

		goto out;

	ASSERT_EQ(errno, EOPNOTSUPP, "errno");



	err = bpf_map_update_elem(map_fd, &task_fd, &value, BPF_EXIST);

	if (!ASSERT_ERR(err, "update_elem(udata, BPF_EXIST)"))

		goto out;

	ASSERT_EQ(errno, ENOENT, "errno");



	err = bpf_map_update_elem(map_fd, &task_fd, &value, BPF_NOEXIST);

	if (!ASSERT_OK(err, "update_elem(udata, BPF_NOEXIST)"))

		goto out;



	value.udata = &udata2;

	err = bpf_map_update_elem(map_fd, &task_fd, &value, BPF_NOEXIST);

	if (!ASSERT_ERR(err, "update_elem(udata2, BPF_NOEXIST)"))

		goto out;

	ASSERT_EQ(errno, EEXIST, "errno");



out:

	uptr_update_failure__destroy(skel);

	close(task_fd);

}



void test_task_local_storage(void)

{

	if (test__start_subtest("sys_enter_exit"))
@@ -422,4 +465,6 @@ void test_task_local_storage(void) 
		test_uptr_basic();

	if (test__start_subtest("uptr_across_pages"))

		test_uptr_across_pages();

	if (test__start_subtest("uptr_update_failure"))

		test_uptr_update_failure();

}

tools/testing/selftests/bpf/progs/uptr_update_failure.c

0 → 100644
+42 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

/* Copyright (c) 2024 Meta Platforms, Inc. and affiliates. */



#include <vmlinux.h>

#include <bpf/bpf_helpers.h>

#include "uptr_test_common.h"



struct {

	__uint(type, BPF_MAP_TYPE_TASK_STORAGE);

	__uint(map_flags, BPF_F_NO_PREALLOC);

	__type(key, int);

	__type(value, struct value_lock_type);

} datamap SEC(".maps");



/* load test only. not used */

SEC("syscall")

int not_used(void *ctx)

{

	struct value_lock_type *ptr;

	struct task_struct *task;

	struct user_data *udata;



	task = bpf_get_current_task_btf();

	ptr = bpf_task_storage_get(&datamap, task, 0, 0);

	if (!ptr)

		return 0;



	bpf_spin_lock(&ptr->lock);



	udata = ptr->udata;

	if (!udata) {

		bpf_spin_unlock(&ptr->lock);

		return 0;

	}

	udata->result = MAGIC_VALUE + udata->a + udata->b;



	bpf_spin_unlock(&ptr->lock);



	return 0;

}



char _license[] SEC("license") = "GPL";

tools/testing/selftests/bpf/uptr_test_common.h

+5 −0
Original line number Diff line number Diff line
@@ -32,4 +32,9 @@ struct value_type { 
	struct nested_udata nested;

};



struct value_lock_type {

	struct user_data __uptr *udata;

	struct bpf_spin_lock lock;

};



#endif