1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (c) 2022 Meta Platforms, Inc. and affiliates. */
3 #include <vmlinux.h>
4 #include <bpf/bpf_tracing.h>
5 #include <bpf/bpf_helpers.h>
6 
7 static struct prog_test_ref_kfunc __kptr *v;
8 long total_sum = -1;
9 
10 extern struct prog_test_ref_kfunc *bpf_kfunc_call_test_acquire(unsigned long *sp) __ksym;
11 extern void bpf_kfunc_call_test_release(struct prog_test_ref_kfunc *p) __ksym;
12 
13 SEC("tc")
14 int test_jit_probe_mem(struct __sk_buff *ctx)
15 {
16 	struct prog_test_ref_kfunc *p;
17 	unsigned long zero = 0, sum;
18 
19 	p = bpf_kfunc_call_test_acquire(&zero);
20 	if (!p)
21 		return 1;
22 
23 	p = bpf_kptr_xchg(&v, p);
24 	if (p)
25 		goto release_out;
26 
27 	/* Direct map value access of kptr, should be PTR_UNTRUSTED */
28 	p = v;
29 	if (!p)
30 		return 1;
31 
32 	asm volatile (
33 		"r9 = %[p];"
34 		"%[sum] = 0;"
35 
36 		/* r8 = p->a */
37 		"r8 = *(u32 *)(r9 + 0);"
38 		"%[sum] += r8;"
39 
40 		/* r8 = p->b */
41 		"r8 = *(u32 *)(r9 + 4);"
42 		"%[sum] += r8;"
43 
44 		"r9 += 8;"
45 		/* r9 = p->a */
46 		"r9 = *(u32 *)(r9 - 8);"
47 		"%[sum] += r9;"
48 
49 		: [sum] "=r"(sum)
50 		: [p] "r"(p)
51 		: "r8", "r9"
52 	);
53 
54 	total_sum = sum;
55 	return 0;
56 release_out:
57 	bpf_kfunc_call_test_release(p);
58 	return 1;
59 }
60 
61 char _license[] SEC("license") = "GPL";
62