1 // SPDX-License-Identifier: GPL-2.0 2 /* Copyright (c) 2020 Facebook */ 3 #include <linux/btf.h> 4 #include <linux/btf_ids.h> 5 #include <linux/error-injection.h> 6 #include <linux/init.h> 7 #include <linux/module.h> 8 #include <linux/percpu-defs.h> 9 #include <linux/sysfs.h> 10 #include <linux/tracepoint.h> 11 #include "bpf_testmod.h" 12 13 #define CREATE_TRACE_POINTS 14 #include "bpf_testmod-events.h" 15 16 typedef int (*func_proto_typedef)(long); 17 typedef int (*func_proto_typedef_nested1)(func_proto_typedef); 18 typedef int (*func_proto_typedef_nested2)(func_proto_typedef_nested1); 19 20 DEFINE_PER_CPU(int, bpf_testmod_ksym_percpu) = 123; 21 22 noinline void 23 bpf_testmod_test_mod_kfunc(int i) 24 { 25 *(int *)this_cpu_ptr(&bpf_testmod_ksym_percpu) = i; 26 } 27 28 struct bpf_testmod_btf_type_tag_1 { 29 int a; 30 }; 31 32 struct bpf_testmod_btf_type_tag_2 { 33 struct bpf_testmod_btf_type_tag_1 __user *p; 34 }; 35 36 noinline int 37 bpf_testmod_test_btf_type_tag_user_1(struct bpf_testmod_btf_type_tag_1 __user *arg) { 38 BTF_TYPE_EMIT(func_proto_typedef); 39 BTF_TYPE_EMIT(func_proto_typedef_nested1); 40 BTF_TYPE_EMIT(func_proto_typedef_nested2); 41 return arg->a; 42 } 43 44 noinline int 45 bpf_testmod_test_btf_type_tag_user_2(struct bpf_testmod_btf_type_tag_2 *arg) { 46 return arg->p->a; 47 } 48 49 noinline int bpf_testmod_loop_test(int n) 50 { 51 int i, sum = 0; 52 53 /* the primary goal of this test is to test LBR. Create a lot of 54 * branches in the function, so we can catch it easily. 55 */ 56 for (i = 0; i < n; i++) 57 sum += i; 58 return sum; 59 } 60 61 __weak noinline struct file *bpf_testmod_return_ptr(int arg) 62 { 63 static struct file f = {}; 64 65 switch (arg) { 66 case 1: return (void *)EINVAL; /* user addr */ 67 case 2: return (void *)0xcafe4a11; /* user addr */ 68 case 3: return (void *)-EINVAL; /* canonical, but invalid */ 69 case 4: return (void *)(1ull << 60); /* non-canonical and invalid */ 70 case 5: return (void *)~(1ull << 30); /* trigger extable */ 71 case 6: return &f; /* valid addr */ 72 case 7: return (void *)((long)&f | 1); /* kernel tricks */ 73 default: return NULL; 74 } 75 } 76 77 noinline ssize_t 78 bpf_testmod_test_read(struct file *file, struct kobject *kobj, 79 struct bin_attribute *bin_attr, 80 char *buf, loff_t off, size_t len) 81 { 82 struct bpf_testmod_test_read_ctx ctx = { 83 .buf = buf, 84 .off = off, 85 .len = len, 86 }; 87 int i = 1; 88 89 while (bpf_testmod_return_ptr(i)) 90 i++; 91 92 /* This is always true. Use the check to make sure the compiler 93 * doesn't remove bpf_testmod_loop_test. 94 */ 95 if (bpf_testmod_loop_test(101) > 100) 96 trace_bpf_testmod_test_read(current, &ctx); 97 98 /* Magic number to enable writable tp */ 99 if (len == 64) { 100 struct bpf_testmod_test_writable_ctx writable = { 101 .val = 1024, 102 }; 103 trace_bpf_testmod_test_writable_bare(&writable); 104 if (writable.early_ret) 105 return snprintf(buf, len, "%d\n", writable.val); 106 } 107 108 return -EIO; /* always fail */ 109 } 110 EXPORT_SYMBOL(bpf_testmod_test_read); 111 ALLOW_ERROR_INJECTION(bpf_testmod_test_read, ERRNO); 112 113 noinline ssize_t 114 bpf_testmod_test_write(struct file *file, struct kobject *kobj, 115 struct bin_attribute *bin_attr, 116 char *buf, loff_t off, size_t len) 117 { 118 struct bpf_testmod_test_write_ctx ctx = { 119 .buf = buf, 120 .off = off, 121 .len = len, 122 }; 123 124 trace_bpf_testmod_test_write_bare(current, &ctx); 125 126 return -EIO; /* always fail */ 127 } 128 EXPORT_SYMBOL(bpf_testmod_test_write); 129 ALLOW_ERROR_INJECTION(bpf_testmod_test_write, ERRNO); 130 131 static struct bin_attribute bin_attr_bpf_testmod_file __ro_after_init = { 132 .attr = { .name = "bpf_testmod", .mode = 0666, }, 133 .read = bpf_testmod_test_read, 134 .write = bpf_testmod_test_write, 135 }; 136 137 BTF_SET_START(bpf_testmod_check_kfunc_ids) 138 BTF_ID(func, bpf_testmod_test_mod_kfunc) 139 BTF_SET_END(bpf_testmod_check_kfunc_ids) 140 141 static const struct btf_kfunc_id_set bpf_testmod_kfunc_set = { 142 .owner = THIS_MODULE, 143 .check_set = &bpf_testmod_check_kfunc_ids, 144 }; 145 146 extern int bpf_fentry_test1(int a); 147 148 static int bpf_testmod_init(void) 149 { 150 int ret; 151 152 ret = register_btf_kfunc_id_set(BPF_PROG_TYPE_SCHED_CLS, &bpf_testmod_kfunc_set); 153 if (ret < 0) 154 return ret; 155 if (bpf_fentry_test1(0) < 0) 156 return -EINVAL; 157 return sysfs_create_bin_file(kernel_kobj, &bin_attr_bpf_testmod_file); 158 } 159 160 static void bpf_testmod_exit(void) 161 { 162 return sysfs_remove_bin_file(kernel_kobj, &bin_attr_bpf_testmod_file); 163 } 164 165 module_init(bpf_testmod_init); 166 module_exit(bpf_testmod_exit); 167 168 MODULE_AUTHOR("Andrii Nakryiko"); 169 MODULE_DESCRIPTION("BPF selftests module"); 170 MODULE_LICENSE("Dual BSD/GPL"); 171