bpf: selftest: Ensure the return value of the bpf_per_cpu_ptr() must be checked (8568c3ce) · Commits · 戴 / test

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

+39 −18

Original line number	Diff line number	Diff line
		@@ -5,18 +5,17 @@
		#include <bpf/libbpf.h>
		#include <bpf/btf.h>
		#include "test_ksyms_btf.skel.h"
		#include "test_ksyms_btf_null_check.skel.h"

		static int duration;

		void test_ksyms_btf(void)
		static void test_basic(void)
		{
		__u64 runqueues_addr, bpf_prog_active_addr;
		__u32 this_rq_cpu;
		int this_bpf_prog_active;
		struct test_ksyms_btf *skel = NULL;
		struct test_ksyms_btf__data *data;
		struct btf *btf;
		int percpu_datasec;
		int err;

		err = kallsyms_find("runqueues", &runqueues_addr);
		@@ -31,20 +30,6 @@ void test_ksyms_btf(void)
		if (CHECK(err == -ENOENT, "ksym_find", "symbol 'bpf_prog_active' not found\n"))
		return;

		btf = libbpf_find_kernel_btf();
		if (CHECK(IS_ERR(btf), "btf_exists", "failed to load kernel BTF: %ld\n",
		PTR_ERR(btf)))
		return;

		percpu_datasec = btf__find_by_name_kind(btf, ".data..percpu",
		BTF_KIND_DATASEC);
		if (percpu_datasec < 0) {
		printf("%s:SKIP:no PERCPU DATASEC in kernel btf\n",
		__func__);
		test__skip();
		goto cleanup;
		}

		skel = test_ksyms_btf__open_and_load();
		if (CHECK(!skel, "skel_open", "failed to open and load skeleton\n"))
		goto cleanup;
		@@ -83,6 +68,42 @@ void test_ksyms_btf(void)
		data->out__bpf_prog_active);

		cleanup:
		btf__free(btf);
		test_ksyms_btf__destroy(skel);
		}

		static void test_null_check(void)
		{
		struct test_ksyms_btf_null_check *skel;

		skel = test_ksyms_btf_null_check__open_and_load();
		CHECK(skel, "skel_open", "unexpected load of a prog missing null check\n");

		test_ksyms_btf_null_check__destroy(skel);
		}

		void test_ksyms_btf(void)
		{
		int percpu_datasec;
		struct btf *btf;

		btf = libbpf_find_kernel_btf();
		if (CHECK(IS_ERR(btf), "btf_exists", "failed to load kernel BTF: %ld\n",
		PTR_ERR(btf)))
		return;

		percpu_datasec = btf__find_by_name_kind(btf, ".data..percpu",
		BTF_KIND_DATASEC);
		btf__free(btf);
		if (percpu_datasec < 0) {
		printf("%s:SKIP:no PERCPU DATASEC in kernel btf\n",
		__func__);
		test__skip();
		return;
		}

		if (test__start_subtest("basic"))
		test_basic();

		if (test__start_subtest("null_check"))
		test_null_check();
		}

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

0 → 100644

+31 −0

Original line number	Diff line number	Diff line
		// SPDX-License-Identifier: GPL-2.0
		/* Copyright (c) 2020 Facebook */

		#include "vmlinux.h"

		#include <bpf/bpf_helpers.h>

		extern const struct rq runqueues __ksym; /* struct type global var. */
		extern const int bpf_prog_active __ksym; /* int type global var. */

		SEC("raw_tp/sys_enter")
		int handler(const void *ctx)
		{
		struct rq *rq;
		int *active;
		__u32 cpu;

		cpu = bpf_get_smp_processor_id();
		rq = (struct rq *)bpf_per_cpu_ptr(&runqueues, cpu);
		active = (int *)bpf_per_cpu_ptr(&bpf_prog_active, cpu);
		if (active) {
		/* READ_ONCE */
		(volatile int )active;
		/* !rq has not been tested, so verifier should reject. */
		(volatile int )(&rq->cpu);
		}

		return 0;
		}

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

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