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// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2020 Facebook */
#include <linux/btf.h>
#include <linux/btf_ids.h>
#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"
#define CREATE_TRACE_POINTS
#include "bpf_testmod-events.h"
DEFINE_PER_CPU(int, bpf_testmod_ksym_percpu) = 123;
noinline void
bpf_testmod_test_mod_kfunc(int i)
{
*(int *)this_cpu_ptr(&bpf_testmod_ksym_percpu) = i;
}
noinline int bpf_testmod_loop_test(int n)
{
int i, sum = 0;
/* the primary goal of this test is to test LBR. Create a lot of
* branches in the function, so we can catch it easily.
*/
for (i = 0; i < n; i++)
sum += i;
return sum;
}
__weak noinline struct file *bpf_testmod_return_ptr(int arg)
{
static struct file f = {};
switch (arg) {
case 1: return (void *)EINVAL; /* user addr */
case 2: return (void *)0xcafe4a11; /* user addr */
case 3: return (void *)-EINVAL; /* canonical, but invalid */
case 4: return (void *)(1ull << 60); /* non-canonical and invalid */
case 5: return (void *)~(1ull << 30); /* trigger extable */
case 6: return &f; /* valid addr */
case 7: return (void *)((long)&f | 1); /* kernel tricks */
default: return NULL;
}
}
noinline ssize_t
bpf_testmod_test_read(struct file *file, struct kobject *kobj,
struct bin_attribute *bin_attr,
char *buf, loff_t off, size_t len)
{
struct bpf_testmod_test_read_ctx ctx = {
.buf = buf,
.off = off,
.len = len,
};
int i = 1;
while (bpf_testmod_return_ptr(i))
i++;
/* This is always true. Use the check to make sure the compiler
* doesn't remove bpf_testmod_loop_test.
*/
if (bpf_testmod_loop_test(101) > 100)
trace_bpf_testmod_test_read(current, &ctx);
/* Magic number to enable writable tp */
if (len == 64) {
struct bpf_testmod_test_writable_ctx writable = {
.val = 1024,
};
trace_bpf_testmod_test_writable_bare(&writable);
if (writable.early_ret)
return snprintf(buf, len, "%d\n", writable.val);
}
return -EIO; /* always fail */
}
EXPORT_SYMBOL(bpf_testmod_test_read);
ALLOW_ERROR_INJECTION(bpf_testmod_test_read, ERRNO);
noinline ssize_t
bpf_testmod_test_write(struct file *file, struct kobject *kobj,
struct bin_attribute *bin_attr,
char *buf, loff_t off, size_t len)
{
struct bpf_testmod_test_write_ctx ctx = {
.buf = buf,
.off = off,
.len = len,
};
trace_bpf_testmod_test_write_bare(current, &ctx);
return -EIO; /* always fail */
}
EXPORT_SYMBOL(bpf_testmod_test_write);
ALLOW_ERROR_INJECTION(bpf_testmod_test_write, ERRNO);
static struct bin_attribute bin_attr_bpf_testmod_file __ro_after_init = {
.attr = { .name = "bpf_testmod", .mode = 0666, },
.read = bpf_testmod_test_read,
.write = bpf_testmod_test_write,
};
BTF_SET_START(bpf_testmod_kfunc_ids)
BTF_ID(func, bpf_testmod_test_mod_kfunc)
BTF_SET_END(bpf_testmod_kfunc_ids)
static DEFINE_KFUNC_BTF_ID_SET(&bpf_testmod_kfunc_ids, bpf_testmod_kfunc_btf_set);
static int bpf_testmod_init(void)
{
int ret;
ret = sysfs_create_bin_file(kernel_kobj, &bin_attr_bpf_testmod_file);
if (ret)
return ret;
register_kfunc_btf_id_set(&prog_test_kfunc_list, &bpf_testmod_kfunc_btf_set);
return 0;
}
static void bpf_testmod_exit(void)
{
unregister_kfunc_btf_id_set(&prog_test_kfunc_list, &bpf_testmod_kfunc_btf_set);
return sysfs_remove_bin_file(kernel_kobj, &bin_attr_bpf_testmod_file);
}
module_init(bpf_testmod_init);
module_exit(bpf_testmod_exit);
MODULE_AUTHOR("Andrii Nakryiko");
MODULE_DESCRIPTION("BPF selftests module");
MODULE_LICENSE("Dual BSD/GPL");
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