1// SPDX-License-Identifier: GPL-2.0
2/* Converted from tools/testing/selftests/bpf/verifier/raw_tp_writable.c */
3
4#include <linux/bpf.h>
5#include <bpf/bpf_helpers.h>
6#include "bpf_misc.h"
7
8struct {
9	__uint(type, BPF_MAP_TYPE_HASH);
10	__uint(max_entries, 1);
11	__type(key, long long);
12	__type(value, long long);
13} map_hash_8b SEC(".maps");
14
15SEC("raw_tracepoint.w")
16__description("raw_tracepoint_writable: reject variable offset")
17__failure
18__msg("R6 invalid variable buffer offset: off=0, var_off=(0x0; 0xffffffff)")
19__flag(BPF_F_ANY_ALIGNMENT)
20__naked void tracepoint_writable_reject_variable_offset(void)
21{
22	asm volatile ("					\
23	/* r6 is our tp buffer */			\
24	r6 = *(u64*)(r1 + 0);				\
25	r1 = %[map_hash_8b] ll;				\
26	/* move the key (== 0) to r10-8 */		\
27	w0 = 0;						\
28	r2 = r10;					\
29	r2 += -8;					\
30	*(u64*)(r2 + 0) = r0;				\
31	/* lookup in the map */				\
32	call %[bpf_map_lookup_elem];			\
33	/* exit clean if null */			\
34	if r0 != 0 goto l0_%=;				\
35	exit;						\
36l0_%=:	/* shift the buffer pointer to a variable location */\
37	r0 = *(u32*)(r0 + 0);				\
38	r6 += r0;					\
39	/* clobber whatever's there */			\
40	r7 = 4242;					\
41	*(u64*)(r6 + 0) = r7;				\
42	r0 = 0;						\
43	exit;						\
44"	:
45	: __imm(bpf_map_lookup_elem),
46	  __imm_addr(map_hash_8b)
47	: __clobber_all);
48}
49
50char _license[] SEC("license") = "GPL";
51