xref: /linux/tools/testing/selftests/bpf/progs/arena_atomics.c (revision 2897b1e2a2f44c16e15f8b875b976d9d3f536506)
1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (c) 2024 Meta Platforms, Inc. and affiliates. */
3 #include <linux/bpf.h>
4 #include <bpf/bpf_helpers.h>
5 #include <bpf/bpf_tracing.h>
6 #include <stdbool.h>
7 #include <stdatomic.h>
8 #include "bpf_arena_common.h"
9 
10 struct {
11 	__uint(type, BPF_MAP_TYPE_ARENA);
12 	__uint(map_flags, BPF_F_MMAPABLE);
13 	__uint(max_entries, 10); /* number of pages */
14 #ifdef __TARGET_ARCH_arm64
15 	__ulong(map_extra, 0x1ull << 32); /* start of mmap() region */
16 #else
17 	__ulong(map_extra, 0x1ull << 44); /* start of mmap() region */
18 #endif
19 } arena SEC(".maps");
20 
21 #if defined(ENABLE_ATOMICS_TESTS) && defined(__BPF_FEATURE_ADDR_SPACE_CAST)
22 bool skip_tests __attribute((__section__(".data"))) = false;
23 #else
24 bool skip_tests = true;
25 #endif
26 
27 __u32 pid = 0;
28 
29 __u64 __arena_global add64_value = 1;
30 __u64 __arena_global add64_result = 0;
31 __u32 __arena_global add32_value = 1;
32 __u32 __arena_global add32_result = 0;
33 __u64 __arena_global add_stack_value_copy = 0;
34 __u64 __arena_global add_stack_result = 0;
35 __u64 __arena_global add_noreturn_value = 1;
36 
37 SEC("raw_tp/sys_enter")
38 int add(const void *ctx)
39 {
40 	if (pid != (bpf_get_current_pid_tgid() >> 32))
41 		return 0;
42 #ifdef ENABLE_ATOMICS_TESTS
43 	__u64 add_stack_value = 1;
44 
45 	add64_result = __sync_fetch_and_add(&add64_value, 2);
46 	add32_result = __sync_fetch_and_add(&add32_value, 2);
47 	add_stack_result = __sync_fetch_and_add(&add_stack_value, 2);
48 	add_stack_value_copy = add_stack_value;
49 	__sync_fetch_and_add(&add_noreturn_value, 2);
50 #endif
51 
52 	return 0;
53 }
54 
55 __s64 __arena_global sub64_value = 1;
56 __s64 __arena_global sub64_result = 0;
57 __s32 __arena_global sub32_value = 1;
58 __s32 __arena_global sub32_result = 0;
59 __s64 __arena_global sub_stack_value_copy = 0;
60 __s64 __arena_global sub_stack_result = 0;
61 __s64 __arena_global sub_noreturn_value = 1;
62 
63 SEC("raw_tp/sys_enter")
64 int sub(const void *ctx)
65 {
66 	if (pid != (bpf_get_current_pid_tgid() >> 32))
67 		return 0;
68 #ifdef ENABLE_ATOMICS_TESTS
69 	__u64 sub_stack_value = 1;
70 
71 	sub64_result = __sync_fetch_and_sub(&sub64_value, 2);
72 	sub32_result = __sync_fetch_and_sub(&sub32_value, 2);
73 	sub_stack_result = __sync_fetch_and_sub(&sub_stack_value, 2);
74 	sub_stack_value_copy = sub_stack_value;
75 	__sync_fetch_and_sub(&sub_noreturn_value, 2);
76 #endif
77 
78 	return 0;
79 }
80 
81 #ifdef __BPF_FEATURE_ATOMIC_MEM_ORDERING
82 _Atomic __u64 __arena_global and64_value = (0x110ull << 32);
83 _Atomic __u32 __arena_global and32_value = 0x110;
84 #else
85 __u64 __arena_global and64_value = (0x110ull << 32);
86 __u32 __arena_global and32_value = 0x110;
87 #endif
88 
89 SEC("raw_tp/sys_enter")
90 int and(const void *ctx)
91 {
92 	if (pid != (bpf_get_current_pid_tgid() >> 32))
93 		return 0;
94 #ifdef ENABLE_ATOMICS_TESTS
95 #ifdef __BPF_FEATURE_ATOMIC_MEM_ORDERING
96 	__c11_atomic_fetch_and(&and64_value, 0x011ull << 32, memory_order_relaxed);
97 	__c11_atomic_fetch_and(&and32_value, 0x011, memory_order_relaxed);
98 #else
99 	__sync_fetch_and_and(&and64_value, 0x011ull << 32);
100 	__sync_fetch_and_and(&and32_value, 0x011);
101 #endif
102 #endif
103 
104 	return 0;
105 }
106 
107 #ifdef __BPF_FEATURE_ATOMIC_MEM_ORDERING
108 _Atomic __u32 __arena_global or32_value = 0x110;
109 _Atomic __u64 __arena_global or64_value = (0x110ull << 32);
110 #else
111 __u32 __arena_global or32_value = 0x110;
112 __u64 __arena_global or64_value = (0x110ull << 32);
113 #endif
114 
115 SEC("raw_tp/sys_enter")
116 int or(const void *ctx)
117 {
118 	if (pid != (bpf_get_current_pid_tgid() >> 32))
119 		return 0;
120 #ifdef ENABLE_ATOMICS_TESTS
121 #ifdef __BPF_FEATURE_ATOMIC_MEM_ORDERING
122 	__c11_atomic_fetch_or(&or64_value, 0x011ull << 32, memory_order_relaxed);
123 	__c11_atomic_fetch_or(&or32_value, 0x011, memory_order_relaxed);
124 #else
125 	__sync_fetch_and_or(&or64_value, 0x011ull << 32);
126 	__sync_fetch_and_or(&or32_value, 0x011);
127 #endif
128 #endif
129 
130 	return 0;
131 }
132 
133 #ifdef __BPF_FEATURE_ATOMIC_MEM_ORDERING
134 _Atomic __u64 __arena_global xor64_value = (0x110ull << 32);
135 _Atomic __u32 __arena_global xor32_value = 0x110;
136 #else
137 __u64 __arena_global xor64_value = (0x110ull << 32);
138 __u32 __arena_global xor32_value = 0x110;
139 #endif
140 
141 SEC("raw_tp/sys_enter")
142 int xor(const void *ctx)
143 {
144 	if (pid != (bpf_get_current_pid_tgid() >> 32))
145 		return 0;
146 #ifdef ENABLE_ATOMICS_TESTS
147 #ifdef __BPF_FEATURE_ATOMIC_MEM_ORDERING
148 	__c11_atomic_fetch_xor(&xor64_value, 0x011ull << 32, memory_order_relaxed);
149 	__c11_atomic_fetch_xor(&xor32_value, 0x011, memory_order_relaxed);
150 #else
151 	__sync_fetch_and_xor(&xor64_value, 0x011ull << 32);
152 	__sync_fetch_and_xor(&xor32_value, 0x011);
153 #endif
154 #endif
155 
156 	return 0;
157 }
158 
159 __u32 __arena_global cmpxchg32_value = 1;
160 __u32 __arena_global cmpxchg32_result_fail = 0;
161 __u32 __arena_global cmpxchg32_result_succeed = 0;
162 __u64 __arena_global cmpxchg64_value = 1;
163 __u64 __arena_global cmpxchg64_result_fail = 0;
164 __u64 __arena_global cmpxchg64_result_succeed = 0;
165 
166 SEC("raw_tp/sys_enter")
167 int cmpxchg(const void *ctx)
168 {
169 	if (pid != (bpf_get_current_pid_tgid() >> 32))
170 		return 0;
171 #ifdef ENABLE_ATOMICS_TESTS
172 	cmpxchg64_result_fail = __sync_val_compare_and_swap(&cmpxchg64_value, 0, 3);
173 	cmpxchg64_result_succeed = __sync_val_compare_and_swap(&cmpxchg64_value, 1, 2);
174 
175 	cmpxchg32_result_fail = __sync_val_compare_and_swap(&cmpxchg32_value, 0, 3);
176 	cmpxchg32_result_succeed = __sync_val_compare_and_swap(&cmpxchg32_value, 1, 2);
177 #endif
178 
179 	return 0;
180 }
181 
182 __u64 __arena_global xchg64_value = 1;
183 __u64 __arena_global xchg64_result = 0;
184 __u32 __arena_global xchg32_value = 1;
185 __u32 __arena_global xchg32_result = 0;
186 
187 SEC("raw_tp/sys_enter")
188 int xchg(const void *ctx)
189 {
190 	if (pid != (bpf_get_current_pid_tgid() >> 32))
191 		return 0;
192 #ifdef ENABLE_ATOMICS_TESTS
193 	__u64 val64 = 2;
194 	__u32 val32 = 2;
195 
196 	xchg64_result = __sync_lock_test_and_set(&xchg64_value, val64);
197 	xchg32_result = __sync_lock_test_and_set(&xchg32_value, val32);
198 #endif
199 
200 	return 0;
201 }
202 
203 __u64 __arena_global uaf_sink;
204 volatile __u64 __arena_global uaf_recovery_fails;
205 
206 SEC("syscall")
207 int uaf(const void *ctx)
208 {
209 	if (pid != (bpf_get_current_pid_tgid() >> 32))
210 		return 0;
211 #if defined(ENABLE_ATOMICS_TESTS) && !defined(__TARGET_ARCH_arm64) && \
212     !defined(__TARGET_ARCH_x86)
213 	__u32 __arena *page32;
214 	__u64 __arena *page64;
215 	void __arena *page;
216 
217 	page = bpf_arena_alloc_pages(&arena, NULL, 1, NUMA_NO_NODE, 0);
218 	bpf_arena_free_pages(&arena, page, 1);
219 	uaf_recovery_fails = 24;
220 
221 	page32 = (__u32 __arena *)page;
222 	uaf_sink += __sync_fetch_and_add(page32, 1);
223 	uaf_recovery_fails -= 1;
224 	__sync_add_and_fetch(page32, 1);
225 	uaf_recovery_fails -= 1;
226 	uaf_sink += __sync_fetch_and_sub(page32, 1);
227 	uaf_recovery_fails -= 1;
228 	__sync_sub_and_fetch(page32, 1);
229 	uaf_recovery_fails -= 1;
230 	uaf_sink += __sync_fetch_and_and(page32, 1);
231 	uaf_recovery_fails -= 1;
232 	__sync_and_and_fetch(page32, 1);
233 	uaf_recovery_fails -= 1;
234 	uaf_sink += __sync_fetch_and_or(page32, 1);
235 	uaf_recovery_fails -= 1;
236 	__sync_or_and_fetch(page32, 1);
237 	uaf_recovery_fails -= 1;
238 	uaf_sink += __sync_fetch_and_xor(page32, 1);
239 	uaf_recovery_fails -= 1;
240 	__sync_xor_and_fetch(page32, 1);
241 	uaf_recovery_fails -= 1;
242 	uaf_sink += __sync_val_compare_and_swap(page32, 0, 1);
243 	uaf_recovery_fails -= 1;
244 	uaf_sink += __sync_lock_test_and_set(page32, 1);
245 	uaf_recovery_fails -= 1;
246 
247 	page64 = (__u64 __arena *)page;
248 	uaf_sink += __sync_fetch_and_add(page64, 1);
249 	uaf_recovery_fails -= 1;
250 	__sync_add_and_fetch(page64, 1);
251 	uaf_recovery_fails -= 1;
252 	uaf_sink += __sync_fetch_and_sub(page64, 1);
253 	uaf_recovery_fails -= 1;
254 	__sync_sub_and_fetch(page64, 1);
255 	uaf_recovery_fails -= 1;
256 	uaf_sink += __sync_fetch_and_and(page64, 1);
257 	uaf_recovery_fails -= 1;
258 	__sync_and_and_fetch(page64, 1);
259 	uaf_recovery_fails -= 1;
260 	uaf_sink += __sync_fetch_and_or(page64, 1);
261 	uaf_recovery_fails -= 1;
262 	__sync_or_and_fetch(page64, 1);
263 	uaf_recovery_fails -= 1;
264 	uaf_sink += __sync_fetch_and_xor(page64, 1);
265 	uaf_recovery_fails -= 1;
266 	__sync_xor_and_fetch(page64, 1);
267 	uaf_recovery_fails -= 1;
268 	uaf_sink += __sync_val_compare_and_swap(page64, 0, 1);
269 	uaf_recovery_fails -= 1;
270 	uaf_sink += __sync_lock_test_and_set(page64, 1);
271 	uaf_recovery_fails -= 1;
272 #endif
273 
274 	return 0;
275 }
276 
277 char _license[] SEC("license") = "GPL";
278