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// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2021 Facebook */
#include <vmlinux.h>
#include <bpf/bpf_helpers.h>
#include "../test_kmods/bpf_testmod_kfunc.h"
static struct bpf_spin_lock kfunc_call_lock SEC(".data.A");
SEC("?tc")
int kfunc_call_test_spin_lock_unsafe(struct __sk_buff *skb)
{
bpf_spin_lock(&kfunc_call_lock);
bpf_kfunc_trigger_ctx_check();
bpf_spin_unlock(&kfunc_call_lock);
return 0;
}
struct syscall_test_args {
__u8 data[16];
size_t size;
};
SEC("?syscall")
int kfunc_syscall_test_fail(struct syscall_test_args *args)
{
bpf_kfunc_call_test_mem_len_pass1(&args->data, sizeof(*args) + 1);
return 0;
}
SEC("?syscall")
int kfunc_syscall_test_null_fail(struct syscall_test_args *args)
{
/* Must be called with args as a NULL pointer
* we do not check for it to have the verifier consider that
* the pointer might not be null, and so we can load it.
*
* So the following can not be added:
*
* if (args)
* return -22;
*/
bpf_kfunc_call_test_mem_len_pass1(args, sizeof(*args));
return 0;
}
SEC("?tc")
int kfunc_call_test_get_mem_fail_rdonly(struct __sk_buff *skb)
{
struct prog_test_ref_kfunc *pt;
unsigned long s = 0;
int *p = NULL;
int ret = 0;
pt = bpf_kfunc_call_test_acquire(&s);
if (pt) {
p = bpf_kfunc_call_test_get_rdonly_mem(pt, 2 * sizeof(int));
if (p)
p[0] = 42; /* this is a read-only buffer, so -EACCES */
else
ret = -1;
bpf_kfunc_call_test_release(pt);
}
return ret;
}
SEC("?tc")
int kfunc_call_test_get_mem_fail_use_after_free(struct __sk_buff *skb)
{
struct prog_test_ref_kfunc *pt;
unsigned long s = 0;
int *p = NULL;
int ret = 0;
pt = bpf_kfunc_call_test_acquire(&s);
if (pt) {
p = bpf_kfunc_call_test_get_rdwr_mem(pt, 2 * sizeof(int));
if (p) {
p[0] = 42;
ret = p[1]; /* 108 */
} else {
ret = -1;
}
bpf_kfunc_call_test_release(pt);
}
if (p)
ret = p[0]; /* p is not valid anymore */
return ret;
}
SEC("?tc")
int kfunc_call_test_get_mem_fail_oob(struct __sk_buff *skb)
{
struct prog_test_ref_kfunc *pt;
unsigned long s = 0;
int *p = NULL;
int ret = 0;
pt = bpf_kfunc_call_test_acquire(&s);
if (pt) {
p = bpf_kfunc_call_test_get_rdonly_mem(pt, 2 * sizeof(int));
if (p)
ret = p[2 * sizeof(int)]; /* oob access, so -EACCES */
else
ret = -1;
bpf_kfunc_call_test_release(pt);
}
return ret;
}
SEC("?tc")
int kfunc_call_test_get_mem_fail_zero_size(struct __sk_buff *skb)
{
struct prog_test_ref_kfunc *pt;
unsigned long s = 0;
int *p = NULL;
int ret = 0;
pt = bpf_kfunc_call_test_acquire(&s);
if (pt) {
/*
* An explicit rdwr_buf_size of 0 gives R0 a zero-sized buffer,
* so any access is out of bounds, hence -EACCES. Previously the
* verifier treated a zero size as "no size argument" and sized
* R0 after the pointed-to return type, wrongly allowing the read.
*/
p = bpf_kfunc_call_test_get_rdwr_mem(pt, 0);
if (p)
ret = p[0];
else
ret = -1;
bpf_kfunc_call_test_release(pt);
}
return ret;
}
SEC("?tc")
int kfunc_call_test_get_mem_fail_oversized(struct __sk_buff *skb)
{
struct prog_test_ref_kfunc *pt;
unsigned long s = 0;
int *p = NULL;
int ret = 0;
pt = bpf_kfunc_call_test_acquire(&s);
if (pt) {
/*
* rdwr_buf_size is a const int, so a C literal is narrowed to
* 32 bits before the call. Force the full 64-bit value 2^64 - 192
* (0xffffffffffffff40, > U32_MAX) into the argument register with
* a 64-bit immediate load. The verifier records r0_size from the
* full register value and must reject it before that value is
* truncated into R0's u32 mem_size.
*/
asm volatile (
"r1 = %[pt];"
"r2 = %[oversized] ll;"
"call %[get_rdwr_mem];"
"%[p] = r0;"
: [p] "=r"(p)
: [pt] "r"(pt),
[oversized] "i"(0xffffffffffffff40LL),
[get_rdwr_mem] "i"(bpf_kfunc_call_test_get_rdwr_mem)
: "r0", "r1", "r2", "r3", "r4", "r5");
bpf_kfunc_call_test_release(pt);
}
return ret;
}
int not_const_size = 2 * sizeof(int);
SEC("?tc")
int kfunc_call_test_get_mem_fail_not_const(struct __sk_buff *skb)
{
struct prog_test_ref_kfunc *pt;
unsigned long s = 0;
int *p = NULL;
int ret = 0;
pt = bpf_kfunc_call_test_acquire(&s);
if (pt) {
p = bpf_kfunc_call_test_get_rdonly_mem(pt, not_const_size); /* non const size, -EINVAL */
if (p)
ret = p[0];
else
ret = -1;
bpf_kfunc_call_test_release(pt);
}
return ret;
}
SEC("?tc")
int kfunc_call_test_mem_acquire_fail(struct __sk_buff *skb)
{
struct prog_test_ref_kfunc *pt;
unsigned long s = 0;
int *p = NULL;
int ret = 0;
pt = bpf_kfunc_call_test_acquire(&s);
if (pt) {
/* we are failing on this one, because we are not acquiring a PTR_TO_BTF_ID (a struct ptr) */
p = bpf_kfunc_call_test_acq_rdonly_mem(pt, 2 * sizeof(int));
if (p)
ret = p[0];
else
ret = -1;
bpf_kfunc_call_int_mem_release(p);
bpf_kfunc_call_test_release(pt);
}
return ret;
}
SEC("?tc")
int kfunc_call_test_pointer_arg_type_mismatch(struct __sk_buff *skb)
{
bpf_kfunc_call_test_pass_ctx((void *)10);
return 0;
}
char _license[] SEC("license") = "GPL";
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