Commit 430d97a8 authored by Andrii Nakryiko's avatar Andrii Nakryiko Committed by Alexei Starovoitov
Browse files

selftests/bpf: Test kernel module ksym externs 



Add per-CPU variable to bpf_testmod.ko and use those from new selftest to
validate it works end-to-end.

Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Acked-by: default avatarYonghong Song <yhs@fb.com>
Acked-by: default avatarHao Luo <haoluo@google.com>
Link: https://lore.kernel.org/bpf/20210112075520.4103414-8-andrii@kernel.org
parent 284d2587

tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c

+3 −0
Original line number Diff line number Diff line
@@ -3,6 +3,7 @@ 
#include <linux/error-injection.h>

#include <linux/init.h>

#include <linux/module.h>

#include <linux/percpu-defs.h>

#include <linux/sysfs.h>

#include <linux/tracepoint.h>

#include "bpf_testmod.h"
@@ -10,6 +11,8 @@ 
#define CREATE_TRACE_POINTS

#include "bpf_testmod-events.h"



DEFINE_PER_CPU(int, bpf_testmod_ksym_percpu) = 123;



noinline ssize_t

bpf_testmod_test_read(struct file *file, struct kobject *kobj,

		      struct bin_attribute *bin_attr,

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

0 → 100644
+31 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

/* Copyright (c) 2021 Facebook */



#include <test_progs.h>

#include <bpf/libbpf.h>

#include <bpf/btf.h>

#include "test_ksyms_module.skel.h"



static int duration;



void test_ksyms_module(void)

{

	struct test_ksyms_module* skel;

	int err;



	skel = test_ksyms_module__open_and_load();

	if (CHECK(!skel, "skel_open", "failed to open skeleton\n"))

		return;



	err = test_ksyms_module__attach(skel);

	if (CHECK(err, "skel_attach", "skeleton attach failed: %d\n", err))

		goto cleanup;



	usleep(1);



	ASSERT_EQ(skel->bss->triggered, true, "triggered");

	ASSERT_EQ(skel->bss->out_mod_ksym_global, 123, "global_ksym_val");



cleanup:

	test_ksyms_module__destroy(skel);

}

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

0 → 100644
+26 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

/* Copyright (c) 2021 Facebook */



#include "vmlinux.h"



#include <bpf/bpf_helpers.h>



extern const int bpf_testmod_ksym_percpu __ksym;



int out_mod_ksym_global = 0;

bool triggered = false;



SEC("raw_tp/sys_enter")

int handler(const void *ctx)

{

	int *val;

	__u32 cpu;



	val = (int *)bpf_this_cpu_ptr(&bpf_testmod_ksym_percpu);

	out_mod_ksym_global = *val;

	triggered = true;



	return 0;

}



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