projects/linux·blob master · refs

273 lines · 5.9 KiB

1// SPDX-License-Identifier: GPL-2.0
2/* Copyright (c) 2026 Meta Platforms, Inc. and affiliates. */
3
4#include <vmlinux.h>
5#include <stdbool.h>
6#include <bpf/bpf_helpers.h>
7#include "bpf_kfuncs.h"
8
9#define CLOCK_MONOTONIC 1
10
11struct timer_elem {
12 struct bpf_timer timer;
13};
14
15struct {
16 __uint(type, BPF_MAP_TYPE_ARRAY);
17 __uint(max_entries, 1);
18 __type(key, int);
19 __type(value, struct timer_elem);
20} timer_map SEC(".maps");
21
22int timer_result;
23
24#if (defined(__TARGET_ARCH_x86) || defined(__TARGET_ARCH_arm64)) && \
25 defined(__BPF_FEATURE_STACK_ARGUMENT)
26
27const volatile bool has_stack_arg = true;
28
29__noinline static int static_func_many_args(int a, int b, int c, int d,
30 int e, int f, int g, int h,
31 int i, int j)
32{
33 return a + b + c + d + e + f + g + h + i + j;
34}
35
36__noinline int global_calls_many_args(int a, int b, int c)
37{
38 return static_func_many_args(a, b, c, a + 3, a + 4, a + 5, a + 6,
39 a + 7, a + 8, a + 9);
40}
41
42SEC("tc")
43int test_global_many_args(void)
44{
45 return global_calls_many_args(1, 2, 3);
46}
47
48struct test_data {
49 long x;
50 long y;
51};
52
53/* 1+2+3+4+5+6+7+8+9+10+20 = 75 */
54__noinline static long func_with_ptr_stack_arg(long a, long b, long c, long d,
55 long e, long f, long g, long h,
56 long i, struct test_data *p)
57{
58 return a + b + c + d + e + f + g + h + i + p->x + p->y;
59}
60
61__noinline long global_ptr_stack_arg(long a, long b, long c, long d, long e)
62{
63 struct test_data data = { .x = 10, .y = 20 };
64
65 return func_with_ptr_stack_arg(a, b, c, d, e, a + 5, a + 6, a + 7,
66 a + 8, &data);
67}
68
69SEC("tc")
70int test_bpf2bpf_ptr_stack_arg(void)
71{
72 return global_ptr_stack_arg(1, 2, 3, 4, 5);
73}
74
75/* 1+2+3+4+5+6+7+10+8+20 = 66 */
76__noinline static long func_with_mix_stack_args(long a, long b, long c, long d,
77 long e, long f, long g,
78 struct test_data *p,
79 long h, struct test_data *q)
80{
81 return a + b + c + d + e + f + g + p->x + h + q->y;
82}
83
84__noinline long global_mix_stack_args(long a, long b, long c, long d, long e)
85{
86 struct test_data p = { .x = 10 };
87 struct test_data q = { .y = 20 };
88
89 return func_with_mix_stack_args(a, b, c, d, e, e + 1, e + 2, &p,
90 e + 3, &q);
91}
92
93SEC("tc")
94int test_bpf2bpf_mix_stack_args(void)
95{
96 return global_mix_stack_args(1, 2, 3, 4, 5);
97}
98
99/*
100 * Nesting test: func_outer calls func_inner, both with struct pointer
101 * as stack arg.
102 *
103 * func_inner: (a+1)+...+(i+1) + p->x + p->y
104 * = 2+3+4+5+6+7+8+9+10+10+20 = 84
105 */
106__noinline static long func_inner_ptr(long a, long b, long c, long d,
107 long e, long f, long g, long h,
108 long i, struct test_data *p)
109{
110 return a + b + c + d + e + f + g + h + i + p->x + p->y;
111}
112
113__noinline static long func_outer_ptr(long a, long b, long c, long d,
114 long e, long f, long g, long h,
115 long i, struct test_data *p)
116{
117 return func_inner_ptr(a + 1, b + 1, c + 1, d + 1, e + 1,
118 f + 1, g + 1, h + 1, i + 1, p);
119}
120
121__noinline long global_nesting_ptr(long a, long b, long c, long d, long e)
122{
123 struct test_data data = { .x = 10, .y = 20 };
124
125 return func_outer_ptr(a, b, c, d, e, a + 5, a + 6, a + 7, a + 8,
126 &data);
127}
128
129SEC("tc")
130int test_bpf2bpf_nesting_stack_arg(void)
131{
132 return global_nesting_ptr(1, 2, 3, 4, 5);
133}
134
135/* 1+2+3+4+5+6+7+8+9+sizeof(pkt_v4) = 45+54 = 99 */
136__noinline static long func_with_dynptr(long a, long b, long c, long d,
137 long e, long f, long g, long h,
138 long i, struct bpf_dynptr *ptr)
139{
140 return a + b + c + d + e + f + g + h + i + bpf_dynptr_size(ptr);
141}
142
143__noinline long global_dynptr_stack_arg(void *ctx __arg_ctx, long a, long b,
144 long c, long d)
145{
146 struct bpf_dynptr ptr;
147
148 bpf_dynptr_from_skb(ctx, 0, &ptr);
149 return func_with_dynptr(a, b, c, d, d + 1, d + 2, d + 3, d + 4,
150 d + 5, &ptr);
151}
152
153SEC("tc")
154int test_bpf2bpf_dynptr_stack_arg(struct __sk_buff *skb)
155{
156 return global_dynptr_stack_arg(skb, 1, 2, 3, 4);
157}
158
159/* foo1: a+b+c+d+e+f+g+h+i+j */
160__noinline static int foo1(int a, int b, int c, int d, int e,
161 int f, int g, int h, int i, int j)
162{
163 return a + b + c + d + e + f + g + h + i + j;
164}
165
166/* foo2: a+b+c+d+e+f+g+h+i+j+k+l */
167__noinline static int foo2(int a, int b, int c, int d, int e,
168 int f, int g, int h, int i, int j,
169 int k, int l)
170{
171 return a + b + c + d + e + f + g + h + i + j + k + l;
172}
173
174/* global_two_callees calls foo1 (5 stack args) and foo2 (7 stack args).
175 * The outgoing stack arg area is sized for foo2 (the larger callee).
176 * Stores for foo1 are a subset of the area used by foo2.
177 * Result: foo1(1..10) + foo2(1..12) = 55 + 78 = 133
178 *
179 * Pass a-e through so the compiler can't constant-fold the stack args away.
180 */
181__noinline int global_two_callees(int a, int b, int c, int d, int e)
182{
183 int ret;
184
185 ret = foo1(a, b, c, d, e, a + 5, a + 6, a + 7, a + 8, a + 9);
186 ret += foo2(a, b, c, d, e, a + 5, a + 6, a + 7, a + 8, a + 9,
187 a + 10, a + 11);
188 return ret;
189}
190
191SEC("tc")
192int test_two_callees(void)
193{
194 return global_two_callees(1, 2, 3, 4, 5);
195}
196
197const volatile int timer_base = 10;
198
199static int timer_cb_many_args(void *map, int *key, struct bpf_timer *timer)
200{
201 int v = timer_base;
202
203 timer_result = static_func_many_args(v, v * 2, v * 3, v * 4, v * 5,
204 v * 6, v * 7, v * 8, v * 9,
205 v * 10);
206 return 0;
207}
208
209SEC("tc")
210int test_async_cb_many_args(void)
211{
212 struct timer_elem *elem;
213 int key = 0;
214
215 elem = bpf_map_lookup_elem(&timer_map, &key);
216 if (!elem)
217 return -1;
218
219 bpf_timer_init(&elem->timer, &timer_map, CLOCK_MONOTONIC);
220 bpf_timer_set_callback(&elem->timer, timer_cb_many_args);
221 bpf_timer_start(&elem->timer, 1, 0);
222 return 0;
223}
224
225#else
226
227const volatile bool has_stack_arg = false;
228
229SEC("tc")
230int test_global_many_args(void)
231{
232 return 0;
233}
234
235SEC("tc")
236int test_bpf2bpf_ptr_stack_arg(void)
237{
238 return 0;
239}
240
241SEC("tc")
242int test_bpf2bpf_mix_stack_args(void)
243{
244 return 0;
245}
246
247SEC("tc")
248int test_bpf2bpf_nesting_stack_arg(void)
249{
250 return 0;
251}
252
253SEC("tc")
254int test_bpf2bpf_dynptr_stack_arg(struct __sk_buff *skb)
255{
256 return 0;
257}
258
259SEC("tc")
260int test_two_callees(void)
261{
262 return 0;
263}
264
265SEC("tc")
266int test_async_cb_many_args(void)
267{
268 return 0;
269}
270
271#endif
272
273char _license[] SEC("license") = "GPL";