ipc/sem.c: fix complex_count vs. simple op race
[linux-2.6-block.git] / include / linux / bpf.h
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1/* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
2 *
3 * This program is free software; you can redistribute it and/or
4 * modify it under the terms of version 2 of the GNU General Public
5 * License as published by the Free Software Foundation.
6 */
7#ifndef _LINUX_BPF_H
8#define _LINUX_BPF_H 1
9
10#include <uapi/linux/bpf.h>
11#include <linux/workqueue.h>
db20fd2b 12#include <linux/file.h>
b121d1e7 13#include <linux/percpu.h>
002245cc 14#include <linux/err.h>
99c55f7d 15
3b1efb19 16struct perf_event;
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17struct bpf_map;
18
19/* map is generic key/value storage optionally accesible by eBPF programs */
20struct bpf_map_ops {
21 /* funcs callable from userspace (via syscall) */
22 struct bpf_map *(*map_alloc)(union bpf_attr *attr);
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23 void (*map_release)(struct bpf_map *map, struct file *map_file);
24 void (*map_free)(struct bpf_map *map);
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25 int (*map_get_next_key)(struct bpf_map *map, void *key, void *next_key);
26
27 /* funcs callable from userspace and from eBPF programs */
28 void *(*map_lookup_elem)(struct bpf_map *map, void *key);
3274f520 29 int (*map_update_elem)(struct bpf_map *map, void *key, void *value, u64 flags);
db20fd2b 30 int (*map_delete_elem)(struct bpf_map *map, void *key);
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31
32 /* funcs called by prog_array and perf_event_array map */
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33 void *(*map_fd_get_ptr)(struct bpf_map *map, struct file *map_file,
34 int fd);
35 void (*map_fd_put_ptr)(void *ptr);
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36};
37
38struct bpf_map {
39 atomic_t refcnt;
40 enum bpf_map_type map_type;
41 u32 key_size;
42 u32 value_size;
43 u32 max_entries;
6c905981 44 u32 map_flags;
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45 u32 pages;
46 struct user_struct *user;
a2c83fff 47 const struct bpf_map_ops *ops;
99c55f7d 48 struct work_struct work;
c9da161c 49 atomic_t usercnt;
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50};
51
52struct bpf_map_type_list {
53 struct list_head list_node;
a2c83fff 54 const struct bpf_map_ops *ops;
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55 enum bpf_map_type type;
56};
57
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58/* function argument constraints */
59enum bpf_arg_type {
80f1d68c 60 ARG_DONTCARE = 0, /* unused argument in helper function */
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61
62 /* the following constraints used to prototype
63 * bpf_map_lookup/update/delete_elem() functions
64 */
65 ARG_CONST_MAP_PTR, /* const argument used as pointer to bpf_map */
66 ARG_PTR_TO_MAP_KEY, /* pointer to stack used as map key */
67 ARG_PTR_TO_MAP_VALUE, /* pointer to stack used as map value */
68
69 /* the following constraints used to prototype bpf_memcmp() and other
70 * functions that access data on eBPF program stack
71 */
72 ARG_PTR_TO_STACK, /* any pointer to eBPF program stack */
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73 ARG_PTR_TO_RAW_STACK, /* any pointer to eBPF program stack, area does not
74 * need to be initialized, helper function must fill
75 * all bytes or clear them in error case.
76 */
77
17a52670 78 ARG_CONST_STACK_SIZE, /* number of bytes accessed from stack */
8e2fe1d9 79 ARG_CONST_STACK_SIZE_OR_ZERO, /* number of bytes accessed from stack or 0 */
80f1d68c 80
608cd71a 81 ARG_PTR_TO_CTX, /* pointer to context */
80f1d68c 82 ARG_ANYTHING, /* any (initialized) argument is ok */
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83};
84
85/* type of values returned from helper functions */
86enum bpf_return_type {
87 RET_INTEGER, /* function returns integer */
88 RET_VOID, /* function doesn't return anything */
89 RET_PTR_TO_MAP_VALUE_OR_NULL, /* returns a pointer to map elem value or NULL */
90};
91
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92/* eBPF function prototype used by verifier to allow BPF_CALLs from eBPF programs
93 * to in-kernel helper functions and for adjusting imm32 field in BPF_CALL
94 * instructions after verifying
95 */
96struct bpf_func_proto {
97 u64 (*func)(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
98 bool gpl_only;
36bbef52 99 bool pkt_access;
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100 enum bpf_return_type ret_type;
101 enum bpf_arg_type arg1_type;
102 enum bpf_arg_type arg2_type;
103 enum bpf_arg_type arg3_type;
104 enum bpf_arg_type arg4_type;
105 enum bpf_arg_type arg5_type;
106};
107
108/* bpf_context is intentionally undefined structure. Pointer to bpf_context is
109 * the first argument to eBPF programs.
110 * For socket filters: 'struct bpf_context *' == 'struct sk_buff *'
111 */
112struct bpf_context;
113
114enum bpf_access_type {
115 BPF_READ = 1,
116 BPF_WRITE = 2
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117};
118
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119/* types of values stored in eBPF registers */
120enum bpf_reg_type {
121 NOT_INIT = 0, /* nothing was written into register */
122 UNKNOWN_VALUE, /* reg doesn't contain a valid pointer */
123 PTR_TO_CTX, /* reg points to bpf_context */
124 CONST_PTR_TO_MAP, /* reg points to struct bpf_map */
125 PTR_TO_MAP_VALUE, /* reg points to map element value */
126 PTR_TO_MAP_VALUE_OR_NULL,/* points to map elem value or NULL */
127 FRAME_PTR, /* reg == frame_pointer */
128 PTR_TO_STACK, /* reg == frame_pointer + imm */
129 CONST_IMM, /* constant integer value */
130
131 /* PTR_TO_PACKET represents:
132 * skb->data
133 * skb->data + imm
134 * skb->data + (u16) var
135 * skb->data + (u16) var + imm
136 * if (range > 0) then [ptr, ptr + range - off) is safe to access
137 * if (id > 0) means that some 'var' was added
138 * if (off > 0) menas that 'imm' was added
139 */
140 PTR_TO_PACKET,
141 PTR_TO_PACKET_END, /* skb->data + headlen */
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142
143 /* PTR_TO_MAP_VALUE_ADJ is used for doing pointer math inside of a map
144 * elem value. We only allow this if we can statically verify that
145 * access from this register are going to fall within the size of the
146 * map element.
147 */
148 PTR_TO_MAP_VALUE_ADJ,
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149};
150
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151struct bpf_prog;
152
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153struct bpf_verifier_ops {
154 /* return eBPF function prototype for verification */
155 const struct bpf_func_proto *(*get_func_proto)(enum bpf_func_id func_id);
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156
157 /* return true if 'size' wide access at offset 'off' within bpf_context
158 * with 'type' (read or write) is allowed
159 */
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160 bool (*is_valid_access)(int off, int size, enum bpf_access_type type,
161 enum bpf_reg_type *reg_type);
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162 int (*gen_prologue)(struct bpf_insn *insn, bool direct_write,
163 const struct bpf_prog *prog);
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164 u32 (*convert_ctx_access)(enum bpf_access_type type, int dst_reg,
165 int src_reg, int ctx_off,
ff936a04 166 struct bpf_insn *insn, struct bpf_prog *prog);
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167};
168
169struct bpf_prog_type_list {
170 struct list_head list_node;
a2c83fff 171 const struct bpf_verifier_ops *ops;
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172 enum bpf_prog_type type;
173};
174
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175struct bpf_prog_aux {
176 atomic_t refcnt;
24701ece 177 u32 used_map_cnt;
32bbe007 178 u32 max_ctx_offset;
a2c83fff 179 const struct bpf_verifier_ops *ops;
09756af4 180 struct bpf_map **used_maps;
09756af4 181 struct bpf_prog *prog;
aaac3ba9 182 struct user_struct *user;
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183 union {
184 struct work_struct work;
185 struct rcu_head rcu;
186 };
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187};
188
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189struct bpf_array {
190 struct bpf_map map;
191 u32 elem_size;
192 /* 'ownership' of prog_array is claimed by the first program that
193 * is going to use this map or by the first program which FD is stored
194 * in the map to make sure that all callers and callees have the same
195 * prog_type and JITed flag
196 */
197 enum bpf_prog_type owner_prog_type;
198 bool owner_jited;
199 union {
200 char value[0] __aligned(8);
2a36f0b9 201 void *ptrs[0] __aligned(8);
a10423b8 202 void __percpu *pptrs[0] __aligned(8);
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203 };
204};
3b1efb19 205
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206#define MAX_TAIL_CALL_CNT 32
207
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208struct bpf_event_entry {
209 struct perf_event *event;
210 struct file *perf_file;
211 struct file *map_file;
212 struct rcu_head rcu;
213};
214
04fd61ab 215u64 bpf_tail_call(u64 ctx, u64 r2, u64 index, u64 r4, u64 r5);
9940d67c 216u64 bpf_get_stackid(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
d056a788 217
04fd61ab 218bool bpf_prog_array_compatible(struct bpf_array *array, const struct bpf_prog *fp);
bd570ff9 219
0756ea3e 220const struct bpf_func_proto *bpf_get_trace_printk_proto(void);
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221
222typedef unsigned long (*bpf_ctx_copy_t)(void *dst, const void *src,
aa7145c1 223 unsigned long off, unsigned long len);
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224
225u64 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size,
226 void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy);
04fd61ab 227
89aa0758 228#ifdef CONFIG_BPF_SYSCALL
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229DECLARE_PER_CPU(int, bpf_prog_active);
230
0fc174de 231void bpf_register_prog_type(struct bpf_prog_type_list *tl);
61e021f3 232void bpf_register_map_type(struct bpf_map_type_list *tl);
0fc174de 233
0fc174de 234struct bpf_prog *bpf_prog_get(u32 ufd);
113214be 235struct bpf_prog *bpf_prog_get_type(u32 ufd, enum bpf_prog_type type);
59d3656d 236struct bpf_prog *bpf_prog_add(struct bpf_prog *prog, int i);
92117d84 237struct bpf_prog *bpf_prog_inc(struct bpf_prog *prog);
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238void bpf_prog_put(struct bpf_prog *prog);
239
c9da161c 240struct bpf_map *bpf_map_get_with_uref(u32 ufd);
c2101297 241struct bpf_map *__bpf_map_get(struct fd f);
92117d84 242struct bpf_map *bpf_map_inc(struct bpf_map *map, bool uref);
c9da161c 243void bpf_map_put_with_uref(struct bpf_map *map);
61e021f3 244void bpf_map_put(struct bpf_map *map);
6c905981 245int bpf_map_precharge_memlock(u32 pages);
61e021f3 246
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247extern int sysctl_unprivileged_bpf_disabled;
248
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249int bpf_map_new_fd(struct bpf_map *map);
250int bpf_prog_new_fd(struct bpf_prog *prog);
251
252int bpf_obj_pin_user(u32 ufd, const char __user *pathname);
253int bpf_obj_get_user(const char __user *pathname);
254
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255int bpf_percpu_hash_copy(struct bpf_map *map, void *key, void *value);
256int bpf_percpu_array_copy(struct bpf_map *map, void *key, void *value);
257int bpf_percpu_hash_update(struct bpf_map *map, void *key, void *value,
258 u64 flags);
259int bpf_percpu_array_update(struct bpf_map *map, void *key, void *value,
260 u64 flags);
d056a788 261
557c0c6e 262int bpf_stackmap_copy(struct bpf_map *map, void *key, void *value);
15a07b33 263
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264int bpf_fd_array_map_update_elem(struct bpf_map *map, struct file *map_file,
265 void *key, void *value, u64 map_flags);
266void bpf_fd_array_map_clear(struct bpf_map *map);
267
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268/* memcpy that is used with 8-byte aligned pointers, power-of-8 size and
269 * forced to use 'long' read/writes to try to atomically copy long counters.
270 * Best-effort only. No barriers here, since it _will_ race with concurrent
271 * updates from BPF programs. Called from bpf syscall and mostly used with
272 * size 8 or 16 bytes, so ask compiler to inline it.
273 */
274static inline void bpf_long_memcpy(void *dst, const void *src, u32 size)
275{
276 const long *lsrc = src;
277 long *ldst = dst;
278
279 size /= sizeof(long);
280 while (size--)
281 *ldst++ = *lsrc++;
282}
283
61e021f3 284/* verify correctness of eBPF program */
9bac3d6d 285int bpf_check(struct bpf_prog **fp, union bpf_attr *attr);
89aa0758 286#else
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287static inline void bpf_register_prog_type(struct bpf_prog_type_list *tl)
288{
289}
290
291static inline struct bpf_prog *bpf_prog_get(u32 ufd)
292{
293 return ERR_PTR(-EOPNOTSUPP);
294}
295
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296static inline struct bpf_prog *bpf_prog_get_type(u32 ufd,
297 enum bpf_prog_type type)
298{
299 return ERR_PTR(-EOPNOTSUPP);
300}
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301static inline struct bpf_prog *bpf_prog_add(struct bpf_prog *prog, int i)
302{
303 return ERR_PTR(-EOPNOTSUPP);
304}
113214be 305
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306static inline void bpf_prog_put(struct bpf_prog *prog)
307{
308}
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309static inline struct bpf_prog *bpf_prog_inc(struct bpf_prog *prog)
310{
311 return ERR_PTR(-EOPNOTSUPP);
312}
61e021f3 313#endif /* CONFIG_BPF_SYSCALL */
09756af4 314
d0003ec0 315/* verifier prototypes for helper functions called from eBPF programs */
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316extern const struct bpf_func_proto bpf_map_lookup_elem_proto;
317extern const struct bpf_func_proto bpf_map_update_elem_proto;
318extern const struct bpf_func_proto bpf_map_delete_elem_proto;
d0003ec0 319
03e69b50 320extern const struct bpf_func_proto bpf_get_prandom_u32_proto;
c04167ce 321extern const struct bpf_func_proto bpf_get_smp_processor_id_proto;
04fd61ab 322extern const struct bpf_func_proto bpf_tail_call_proto;
17ca8cbf 323extern const struct bpf_func_proto bpf_ktime_get_ns_proto;
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324extern const struct bpf_func_proto bpf_get_current_pid_tgid_proto;
325extern const struct bpf_func_proto bpf_get_current_uid_gid_proto;
326extern const struct bpf_func_proto bpf_get_current_comm_proto;
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327extern const struct bpf_func_proto bpf_skb_vlan_push_proto;
328extern const struct bpf_func_proto bpf_skb_vlan_pop_proto;
d5a3b1f6 329extern const struct bpf_func_proto bpf_get_stackid_proto;
03e69b50 330
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331/* Shared helpers among cBPF and eBPF. */
332void bpf_user_rnd_init_once(void);
333u64 bpf_user_rnd_u32(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
334
99c55f7d 335#endif /* _LINUX_BPF_H */