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
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
|
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __BPF_MISC_H__
#define __BPF_MISC_H__
/* This set of attributes controls behavior of the
* test_loader.c:test_loader__run_subtests().
*
* The test_loader sequentially loads each program in a skeleton.
* Programs could be loaded in privileged and unprivileged modes.
* - __success, __failure, __msg imply privileged mode;
* - __success_unpriv, __failure_unpriv, __msg_unpriv imply
* unprivileged mode.
* If combination of privileged and unprivileged attributes is present
* both modes are used. If none are present privileged mode is implied.
*
* See test_loader.c:drop_capabilities() for exact set of capabilities
* that differ between privileged and unprivileged modes.
*
* For test filtering purposes the name of the program loaded in
* unprivileged mode is derived from the usual program name by adding
* `@unpriv' suffix.
*
* __msg Message expected to be found in the verifier log.
* Multiple __msg attributes could be specified.
* __msg_unpriv Same as __msg but for unprivileged mode.
*
* __success Expect program load success in privileged mode.
* __success_unpriv Expect program load success in unprivileged mode.
*
* __failure Expect program load failure in privileged mode.
* __failure_unpriv Expect program load failure in unprivileged mode.
*
* __description Text to be used instead of a program name for display
* and filtering purposes.
*
* __log_level Log level to use for the program, numeric value expected.
*
* __flag Adds one flag use for the program, the following values are valid:
* - BPF_F_STRICT_ALIGNMENT;
* - BPF_F_TEST_RND_HI32;
* - BPF_F_TEST_STATE_FREQ;
* - BPF_F_SLEEPABLE;
* - BPF_F_XDP_HAS_FRAGS;
* - A numeric value.
* Multiple __flag attributes could be specified, the final flags
* value is derived by applying binary "or" to all specified values.
*/
#define __msg(msg) __attribute__((btf_decl_tag("comment:test_expect_msg=" msg)))
#define __failure __attribute__((btf_decl_tag("comment:test_expect_failure")))
#define __success __attribute__((btf_decl_tag("comment:test_expect_success")))
#define __description(desc) __attribute__((btf_decl_tag("comment:test_description=" desc)))
#define __msg_unpriv(msg) __attribute__((btf_decl_tag("comment:test_expect_msg_unpriv=" msg)))
#define __failure_unpriv __attribute__((btf_decl_tag("comment:test_expect_failure_unpriv")))
#define __success_unpriv __attribute__((btf_decl_tag("comment:test_expect_success_unpriv")))
#define __log_level(lvl) __attribute__((btf_decl_tag("comment:test_log_level="#lvl)))
#define __flag(flag) __attribute__((btf_decl_tag("comment:test_prog_flags="#flag)))
/* Convenience macro for use with 'asm volatile' blocks */
#define __naked __attribute__((naked))
#define __clobber_all "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7", "r8", "r9", "memory"
#define __clobber_common "r0", "r1", "r2", "r3", "r4", "r5", "memory"
#define __imm(name) [name]"i"(name)
#define __imm_const(name, expr) [name]"i"(expr)
#define __imm_addr(name) [name]"i"(&name)
#define __imm_ptr(name) [name]"p"(&name)
#define __imm_insn(name, expr) [name]"i"(*(long *)&(expr))
#if defined(__TARGET_ARCH_x86)
#define SYSCALL_WRAPPER 1
#define SYS_PREFIX "__x64_"
#elif defined(__TARGET_ARCH_s390)
#define SYSCALL_WRAPPER 1
#define SYS_PREFIX "__s390x_"
#elif defined(__TARGET_ARCH_arm64)
#define SYSCALL_WRAPPER 1
#define SYS_PREFIX "__arm64_"
#else
#define SYSCALL_WRAPPER 0
#define SYS_PREFIX "__se_"
#endif
/* How many arguments are passed to function in register */
#if defined(__TARGET_ARCH_x86) || defined(__x86_64__)
#define FUNC_REG_ARG_CNT 6
#elif defined(__i386__)
#define FUNC_REG_ARG_CNT 3
#elif defined(__TARGET_ARCH_s390) || defined(__s390x__)
#define FUNC_REG_ARG_CNT 5
#elif defined(__TARGET_ARCH_arm) || defined(__arm__)
#define FUNC_REG_ARG_CNT 4
#elif defined(__TARGET_ARCH_arm64) || defined(__aarch64__)
#define FUNC_REG_ARG_CNT 8
#elif defined(__TARGET_ARCH_mips) || defined(__mips__)
#define FUNC_REG_ARG_CNT 8
#elif defined(__TARGET_ARCH_powerpc) || defined(__powerpc__) || defined(__powerpc64__)
#define FUNC_REG_ARG_CNT 8
#elif defined(__TARGET_ARCH_sparc) || defined(__sparc__)
#define FUNC_REG_ARG_CNT 6
#elif defined(__TARGET_ARCH_riscv) || defined(__riscv__)
#define FUNC_REG_ARG_CNT 8
#else
/* default to 5 for others */
#define FUNC_REG_ARG_CNT 5
#endif
/* make it look to compiler like value is read and written */
#define __sink(expr) asm volatile("" : "+g"(expr))
struct bpf_iter_num;
extern int bpf_iter_num_new(struct bpf_iter_num *it, int start, int end) __ksym;
extern int *bpf_iter_num_next(struct bpf_iter_num *it) __ksym;
extern void bpf_iter_num_destroy(struct bpf_iter_num *it) __ksym;
#ifndef bpf_for_each
/* bpf_for_each(iter_type, cur_elem, args...) provides generic construct for
* using BPF open-coded iterators without having to write mundane explicit
* low-level loop logic. Instead, it provides for()-like generic construct
* that can be used pretty naturally. E.g., for some hypothetical cgroup
* iterator, you'd write:
*
* struct cgroup *cg, *parent_cg = <...>;
*
* bpf_for_each(cgroup, cg, parent_cg, CG_ITER_CHILDREN) {
* bpf_printk("Child cgroup id = %d", cg->cgroup_id);
* if (cg->cgroup_id == 123)
* break;
* }
*
* I.e., it looks almost like high-level for each loop in other languages,
* supports continue/break, and is verifiable by BPF verifier.
*
* For iterating integers, the difference betwen bpf_for_each(num, i, N, M)
* and bpf_for(i, N, M) is in that bpf_for() provides additional proof to
* verifier that i is in [N, M) range, and in bpf_for_each() case i is `int
* *`, not just `int`. So for integers bpf_for() is more convenient.
*
* Note: this macro relies on C99 feature of allowing to declare variables
* inside for() loop, bound to for() loop lifetime. It also utilizes GCC
* extension: __attribute__((cleanup(<func>))), supported by both GCC and
* Clang.
*/
#define bpf_for_each(type, cur, args...) for ( \
/* initialize and define destructor */ \
struct bpf_iter_##type ___it __attribute__((aligned(8), /* enforce, just in case */, \
cleanup(bpf_iter_##type##_destroy))), \
/* ___p pointer is just to call bpf_iter_##type##_new() *once* to init ___it */ \
*___p __attribute__((unused)) = ( \
bpf_iter_##type##_new(&___it, ##args), \
/* this is a workaround for Clang bug: it currently doesn't emit BTF */ \
/* for bpf_iter_##type##_destroy() when used from cleanup() attribute */ \
(void)bpf_iter_##type##_destroy, (void *)0); \
/* iteration and termination check */ \
(((cur) = bpf_iter_##type##_next(&___it))); \
)
#endif /* bpf_for_each */
#ifndef bpf_for
/* bpf_for(i, start, end) implements a for()-like looping construct that sets
* provided integer variable *i* to values starting from *start* through,
* but not including, *end*. It also proves to BPF verifier that *i* belongs
* to range [start, end), so this can be used for accessing arrays without
* extra checks.
*
* Note: *start* and *end* are assumed to be expressions with no side effects
* and whose values do not change throughout bpf_for() loop execution. They do
* not have to be statically known or constant, though.
*
* Note: similarly to bpf_for_each(), it relies on C99 feature of declaring for()
* loop bound variables and cleanup attribute, supported by GCC and Clang.
*/
#define bpf_for(i, start, end) for ( \
/* initialize and define destructor */ \
struct bpf_iter_num ___it __attribute__((aligned(8), /* enforce, just in case */ \
cleanup(bpf_iter_num_destroy))), \
/* ___p pointer is necessary to call bpf_iter_num_new() *once* to init ___it */ \
*___p __attribute__((unused)) = ( \
bpf_iter_num_new(&___it, (start), (end)), \
/* this is a workaround for Clang bug: it currently doesn't emit BTF */ \
/* for bpf_iter_num_destroy() when used from cleanup() attribute */ \
(void)bpf_iter_num_destroy, (void *)0); \
({ \
/* iteration step */ \
int *___t = bpf_iter_num_next(&___it); \
/* termination and bounds check */ \
(___t && ((i) = *___t, (i) >= (start) && (i) < (end))); \
}); \
)
#endif /* bpf_for */
#ifndef bpf_repeat
/* bpf_repeat(N) performs N iterations without exposing iteration number
*
* Note: similarly to bpf_for_each(), it relies on C99 feature of declaring for()
* loop bound variables and cleanup attribute, supported by GCC and Clang.
*/
#define bpf_repeat(N) for ( \
/* initialize and define destructor */ \
struct bpf_iter_num ___it __attribute__((aligned(8), /* enforce, just in case */ \
cleanup(bpf_iter_num_destroy))), \
/* ___p pointer is necessary to call bpf_iter_num_new() *once* to init ___it */ \
*___p __attribute__((unused)) = ( \
bpf_iter_num_new(&___it, 0, (N)), \
/* this is a workaround for Clang bug: it currently doesn't emit BTF */ \
/* for bpf_iter_num_destroy() when used from cleanup() attribute */ \
(void)bpf_iter_num_destroy, (void *)0); \
bpf_iter_num_next(&___it); \
/* nothing here */ \
)
#endif /* bpf_repeat */
#endif
|
