Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1// SPDX-License-Identifier: GPL-2.0
2/* Converted from tools/testing/selftests/bpf/verifier/map_in_map.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_ARRAY_OF_MAPS);
10 __uint(max_entries, 1);
11 __type(key, int);
12 __type(value, int);
13 __array(values, struct {
14 __uint(type, BPF_MAP_TYPE_ARRAY);
15 __uint(max_entries, 1);
16 __type(key, int);
17 __type(value, int);
18 });
19} map_in_map SEC(".maps");
20
21SEC("socket")
22__description("map in map access")
23__success __success_unpriv __retval(0)
24__naked void map_in_map_access(void)
25{
26 asm volatile (" \
27 r1 = 0; \
28 *(u32*)(r10 - 4) = r1; \
29 r2 = r10; \
30 r2 += -4; \
31 r1 = %[map_in_map] ll; \
32 call %[bpf_map_lookup_elem]; \
33 if r0 == 0 goto l0_%=; \
34 r1 = 0; \
35 *(u32*)(r10 - 4) = r1; \
36 r2 = r10; \
37 r2 += -4; \
38 r1 = r0; \
39 call %[bpf_map_lookup_elem]; \
40l0_%=: r0 = 0; \
41 exit; \
42" :
43 : __imm(bpf_map_lookup_elem),
44 __imm_addr(map_in_map)
45 : __clobber_all);
46}
47
48SEC("xdp")
49__description("map in map state pruning")
50__success __msg("processed 15 insns")
51__log_level(2) __retval(0) __flag(BPF_F_TEST_STATE_FREQ)
52__naked void map_in_map_state_pruning(void)
53{
54 asm volatile (" \
55 r1 = 0; \
56 *(u32*)(r10 - 4) = r1; \
57 r6 = r10; \
58 r6 += -4; \
59 r2 = r6; \
60 r1 = %[map_in_map] ll; \
61 call %[bpf_map_lookup_elem]; \
62 if r0 != 0 goto l0_%=; \
63 exit; \
64l0_%=: r2 = r6; \
65 r1 = r0; \
66 call %[bpf_map_lookup_elem]; \
67 if r0 != 0 goto l1_%=; \
68 r2 = r6; \
69 r1 = %[map_in_map] ll; \
70 call %[bpf_map_lookup_elem]; \
71 if r0 != 0 goto l2_%=; \
72 exit; \
73l2_%=: r2 = r6; \
74 r1 = r0; \
75 call %[bpf_map_lookup_elem]; \
76 if r0 != 0 goto l1_%=; \
77 exit; \
78l1_%=: r0 = *(u32*)(r0 + 0); \
79 exit; \
80" :
81 : __imm(bpf_map_lookup_elem),
82 __imm_addr(map_in_map)
83 : __clobber_all);
84}
85
86SEC("socket")
87__description("invalid inner map pointer")
88__failure __msg("R1 pointer arithmetic on map_ptr prohibited")
89__failure_unpriv
90__naked void invalid_inner_map_pointer(void)
91{
92 asm volatile (" \
93 r1 = 0; \
94 *(u32*)(r10 - 4) = r1; \
95 r2 = r10; \
96 r2 += -4; \
97 r1 = %[map_in_map] ll; \
98 call %[bpf_map_lookup_elem]; \
99 if r0 == 0 goto l0_%=; \
100 r1 = 0; \
101 *(u32*)(r10 - 4) = r1; \
102 r2 = r10; \
103 r2 += -4; \
104 r1 = r0; \
105 r1 += 8; \
106 call %[bpf_map_lookup_elem]; \
107l0_%=: r0 = 0; \
108 exit; \
109" :
110 : __imm(bpf_map_lookup_elem),
111 __imm_addr(map_in_map)
112 : __clobber_all);
113}
114
115SEC("socket")
116__description("forgot null checking on the inner map pointer")
117__failure __msg("R1 type=map_value_or_null expected=map_ptr")
118__failure_unpriv
119__naked void on_the_inner_map_pointer(void)
120{
121 asm volatile (" \
122 r1 = 0; \
123 *(u32*)(r10 - 4) = r1; \
124 r2 = r10; \
125 r2 += -4; \
126 r1 = %[map_in_map] ll; \
127 call %[bpf_map_lookup_elem]; \
128 r1 = 0; \
129 *(u32*)(r10 - 4) = r1; \
130 r2 = r10; \
131 r2 += -4; \
132 r1 = r0; \
133 call %[bpf_map_lookup_elem]; \
134 r0 = 0; \
135 exit; \
136" :
137 : __imm(bpf_map_lookup_elem),
138 __imm_addr(map_in_map)
139 : __clobber_all);
140}
141
142SEC("socket")
143__description("map_ptr is never null")
144__success
145__naked void map_ptr_is_never_null(void)
146{
147 asm volatile (" \
148 r0 = 0; \
149 r1 = %[map_in_map] ll; \
150 if r1 != 0 goto l0_%=; \
151 r10 = 42; \
152l0_%=: exit; \
153" :
154 : __imm(bpf_map_lookup_elem),
155 __imm_addr(map_in_map)
156 : __clobber_all);
157}
158
159SEC("socket")
160__description("map_ptr is never null inner")
161__success
162__naked void map_ptr_is_never_null_inner(void)
163{
164 asm volatile (" \
165 r1 = 0; \
166 *(u32*)(r10 - 4) = r1; \
167 r2 = r10; \
168 r2 += -4; \
169 r1 = %[map_in_map] ll; \
170 call %[bpf_map_lookup_elem]; \
171 if r0 == 0 goto l0_%=; \
172 if r0 != 0 goto l0_%=; \
173 r10 = 42; \
174l0_%=: exit; \
175" :
176 : __imm(bpf_map_lookup_elem),
177 __imm_addr(map_in_map)
178 : __clobber_all);
179}
180
181SEC("socket")
182__description("map_ptr is never null inner spill fill")
183__success
184__naked void map_ptr_is_never_null_inner_spill_fill(void)
185{
186 asm volatile (" \
187 r1 = 0; \
188 *(u32*)(r10 - 4) = r1; \
189 r2 = r10; \
190 r2 += -4; \
191 r1 = %[map_in_map] ll; \
192 call %[bpf_map_lookup_elem]; \
193 if r0 != 0 goto l0_%=; \
194 exit; \
195l0_%=: *(u64 *)(r10 -16) = r0; \
196 r1 = *(u64 *)(r10 -16); \
197 if r1 == 0 goto l1_%=; \
198 exit; \
199l1_%=: r10 = 42; \
200 exit; \
201" :
202 : __imm(bpf_map_lookup_elem),
203 __imm_addr(map_in_map)
204 : __clobber_all);
205}
206
207struct {
208 __uint(type, BPF_MAP_TYPE_ARRAY_OF_MAPS);
209 __uint(max_entries, 1);
210 __type(key, int);
211 __type(value, int);
212 __array(values, struct {
213 __uint(type, BPF_MAP_TYPE_RINGBUF);
214 __uint(max_entries, 64 * 1024);
215 });
216} rb_in_map SEC(".maps");
217
218struct rb_ctx {
219 void *rb;
220 struct bpf_dynptr dptr;
221};
222
223static __always_inline struct rb_ctx __rb_event_reserve(__u32 sz)
224{
225 struct rb_ctx rb_ctx = {};
226 void *rb;
227 __u32 cpu = bpf_get_smp_processor_id();
228 __u32 rb_slot = cpu & 1;
229
230 rb = bpf_map_lookup_elem(&rb_in_map, &rb_slot);
231 if (!rb)
232 return rb_ctx;
233
234 rb_ctx.rb = rb;
235 bpf_ringbuf_reserve_dynptr(rb, sz, 0, &rb_ctx.dptr);
236
237 return rb_ctx;
238}
239
240static __noinline void __rb_event_submit(struct rb_ctx *ctx)
241{
242 if (!ctx->rb)
243 return;
244
245 /* If the verifier (incorrectly) concludes that ctx->rb can be
246 * NULL at this point, we'll get "BPF_EXIT instruction in main
247 * prog would lead to reference leak" error
248 */
249 bpf_ringbuf_submit_dynptr(&ctx->dptr, 0);
250}
251
252SEC("socket")
253int map_ptr_is_never_null_rb(void *ctx)
254{
255 struct rb_ctx event_ctx = __rb_event_reserve(256);
256 __rb_event_submit(&event_ctx);
257 return 0;
258}
259
260char _license[] SEC("license") = "GPL";