Loading...
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 | // SPDX-License-Identifier: GPL-2.0 #include <linux/bpf.h> #include <bpf/bpf_helpers.h> #include <bpf/bpf_tracing.h> #include <errno.h> char _license[] SEC("license") = "GPL"; __u64 test1_result = 0; SEC("fentry/bpf_fentry_test1") int BPF_PROG(test1) { __u64 cnt = bpf_get_func_arg_cnt(ctx); __u64 a = 0, z = 0, ret = 0; __s64 err; test1_result = cnt == 1; /* valid arguments */ err = bpf_get_func_arg(ctx, 0, &a); /* We need to cast access to traced function argument values with * proper type cast, because trampoline uses type specific instruction * to save it, like for 'int a' with 32-bit mov like: * * mov %edi,-0x8(%rbp) * * so the upper 4 bytes are not zeroed. */ test1_result &= err == 0 && ((int) a == 1); /* not valid argument */ err = bpf_get_func_arg(ctx, 1, &z); test1_result &= err == -EINVAL; /* return value fails in fentry */ err = bpf_get_func_ret(ctx, &ret); test1_result &= err == -EOPNOTSUPP; return 0; } __u64 test2_result = 0; SEC("fexit/bpf_fentry_test2") int BPF_PROG(test2) { __u64 cnt = bpf_get_func_arg_cnt(ctx); __u64 a = 0, b = 0, z = 0, ret = 0; __s64 err; test2_result = cnt == 2; /* valid arguments */ err = bpf_get_func_arg(ctx, 0, &a); test2_result &= err == 0 && (int) a == 2; err = bpf_get_func_arg(ctx, 1, &b); test2_result &= err == 0 && b == 3; /* not valid argument */ err = bpf_get_func_arg(ctx, 2, &z); test2_result &= err == -EINVAL; /* return value */ err = bpf_get_func_ret(ctx, &ret); test2_result &= err == 0 && ret == 5; return 0; } __u64 test3_result = 0; SEC("fmod_ret/bpf_modify_return_test") int BPF_PROG(fmod_ret_test, int _a, int *_b, int _ret) { __u64 cnt = bpf_get_func_arg_cnt(ctx); __u64 a = 0, b = 0, z = 0, ret = 0; __s64 err; test3_result = cnt == 2; /* valid arguments */ err = bpf_get_func_arg(ctx, 0, &a); test3_result &= err == 0 && ((int) a == 1); err = bpf_get_func_arg(ctx, 1, &b); test3_result &= err == 0 && ((int *) b == _b); /* not valid argument */ err = bpf_get_func_arg(ctx, 2, &z); test3_result &= err == -EINVAL; /* return value */ err = bpf_get_func_ret(ctx, &ret); test3_result &= err == 0 && ret == 0; /* change return value, it's checked in fexit_test program */ return 1234; } __u64 test4_result = 0; SEC("fexit/bpf_modify_return_test") int BPF_PROG(fexit_test, int _a, int *_b, int _ret) { __u64 cnt = bpf_get_func_arg_cnt(ctx); __u64 a = 0, b = 0, z = 0, ret = 0; __s64 err; test4_result = cnt == 2; /* valid arguments */ err = bpf_get_func_arg(ctx, 0, &a); test4_result &= err == 0 && ((int) a == 1); err = bpf_get_func_arg(ctx, 1, &b); test4_result &= err == 0 && ((int *) b == _b); /* not valid argument */ err = bpf_get_func_arg(ctx, 2, &z); test4_result &= err == -EINVAL; /* return value */ err = bpf_get_func_ret(ctx, &ret); test4_result &= err == 0 && ret == 1234; return 0; } |