Commit | Line | Data |
---|---|---|
f5bffecd AS |
1 | /* |
2 | * Linux Socket Filter - Kernel level socket filtering | |
3 | * | |
4 | * Based on the design of the Berkeley Packet Filter. The new | |
5 | * internal format has been designed by PLUMgrid: | |
6 | * | |
7 | * Copyright (c) 2011 - 2014 PLUMgrid, http://plumgrid.com | |
8 | * | |
9 | * Authors: | |
10 | * | |
11 | * Jay Schulist <jschlst@samba.org> | |
12 | * Alexei Starovoitov <ast@plumgrid.com> | |
13 | * Daniel Borkmann <dborkman@redhat.com> | |
14 | * | |
15 | * This program is free software; you can redistribute it and/or | |
16 | * modify it under the terms of the GNU General Public License | |
17 | * as published by the Free Software Foundation; either version | |
18 | * 2 of the License, or (at your option) any later version. | |
19 | * | |
20 | * Andi Kleen - Fix a few bad bugs and races. | |
4df95ff4 | 21 | * Kris Katterjohn - Added many additional checks in bpf_check_classic() |
f5bffecd | 22 | */ |
738cbe72 | 23 | |
f5bffecd AS |
24 | #include <linux/filter.h> |
25 | #include <linux/skbuff.h> | |
60a3b225 | 26 | #include <linux/vmalloc.h> |
738cbe72 DB |
27 | #include <linux/random.h> |
28 | #include <linux/moduleloader.h> | |
09756af4 | 29 | #include <linux/bpf.h> |
f5bffecd | 30 | |
3324b584 DB |
31 | #include <asm/unaligned.h> |
32 | ||
f5bffecd AS |
33 | /* Registers */ |
34 | #define BPF_R0 regs[BPF_REG_0] | |
35 | #define BPF_R1 regs[BPF_REG_1] | |
36 | #define BPF_R2 regs[BPF_REG_2] | |
37 | #define BPF_R3 regs[BPF_REG_3] | |
38 | #define BPF_R4 regs[BPF_REG_4] | |
39 | #define BPF_R5 regs[BPF_REG_5] | |
40 | #define BPF_R6 regs[BPF_REG_6] | |
41 | #define BPF_R7 regs[BPF_REG_7] | |
42 | #define BPF_R8 regs[BPF_REG_8] | |
43 | #define BPF_R9 regs[BPF_REG_9] | |
44 | #define BPF_R10 regs[BPF_REG_10] | |
45 | ||
46 | /* Named registers */ | |
47 | #define DST regs[insn->dst_reg] | |
48 | #define SRC regs[insn->src_reg] | |
49 | #define FP regs[BPF_REG_FP] | |
50 | #define ARG1 regs[BPF_REG_ARG1] | |
51 | #define CTX regs[BPF_REG_CTX] | |
52 | #define IMM insn->imm | |
53 | ||
54 | /* No hurry in this branch | |
55 | * | |
56 | * Exported for the bpf jit load helper. | |
57 | */ | |
58 | void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb, int k, unsigned int size) | |
59 | { | |
60 | u8 *ptr = NULL; | |
61 | ||
62 | if (k >= SKF_NET_OFF) | |
63 | ptr = skb_network_header(skb) + k - SKF_NET_OFF; | |
64 | else if (k >= SKF_LL_OFF) | |
65 | ptr = skb_mac_header(skb) + k - SKF_LL_OFF; | |
3324b584 | 66 | |
f5bffecd AS |
67 | if (ptr >= skb->head && ptr + size <= skb_tail_pointer(skb)) |
68 | return ptr; | |
69 | ||
70 | return NULL; | |
71 | } | |
72 | ||
60a3b225 DB |
73 | struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags) |
74 | { | |
75 | gfp_t gfp_flags = GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO | | |
76 | gfp_extra_flags; | |
09756af4 | 77 | struct bpf_prog_aux *aux; |
60a3b225 DB |
78 | struct bpf_prog *fp; |
79 | ||
80 | size = round_up(size, PAGE_SIZE); | |
81 | fp = __vmalloc(size, gfp_flags, PAGE_KERNEL); | |
82 | if (fp == NULL) | |
83 | return NULL; | |
84 | ||
a91263d5 DB |
85 | kmemcheck_annotate_bitfield(fp, meta); |
86 | ||
09756af4 AS |
87 | aux = kzalloc(sizeof(*aux), GFP_KERNEL | gfp_extra_flags); |
88 | if (aux == NULL) { | |
60a3b225 DB |
89 | vfree(fp); |
90 | return NULL; | |
91 | } | |
92 | ||
93 | fp->pages = size / PAGE_SIZE; | |
09756af4 | 94 | fp->aux = aux; |
e9d8afa9 | 95 | fp->aux->prog = fp; |
60a3b225 DB |
96 | |
97 | return fp; | |
98 | } | |
99 | EXPORT_SYMBOL_GPL(bpf_prog_alloc); | |
100 | ||
101 | struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size, | |
102 | gfp_t gfp_extra_flags) | |
103 | { | |
104 | gfp_t gfp_flags = GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO | | |
105 | gfp_extra_flags; | |
106 | struct bpf_prog *fp; | |
107 | ||
108 | BUG_ON(fp_old == NULL); | |
109 | ||
110 | size = round_up(size, PAGE_SIZE); | |
111 | if (size <= fp_old->pages * PAGE_SIZE) | |
112 | return fp_old; | |
113 | ||
114 | fp = __vmalloc(size, gfp_flags, PAGE_KERNEL); | |
115 | if (fp != NULL) { | |
a91263d5 DB |
116 | kmemcheck_annotate_bitfield(fp, meta); |
117 | ||
60a3b225 DB |
118 | memcpy(fp, fp_old, fp_old->pages * PAGE_SIZE); |
119 | fp->pages = size / PAGE_SIZE; | |
e9d8afa9 | 120 | fp->aux->prog = fp; |
60a3b225 | 121 | |
09756af4 | 122 | /* We keep fp->aux from fp_old around in the new |
60a3b225 DB |
123 | * reallocated structure. |
124 | */ | |
09756af4 | 125 | fp_old->aux = NULL; |
60a3b225 DB |
126 | __bpf_prog_free(fp_old); |
127 | } | |
128 | ||
129 | return fp; | |
130 | } | |
131 | EXPORT_SYMBOL_GPL(bpf_prog_realloc); | |
132 | ||
133 | void __bpf_prog_free(struct bpf_prog *fp) | |
134 | { | |
09756af4 | 135 | kfree(fp->aux); |
60a3b225 DB |
136 | vfree(fp); |
137 | } | |
138 | EXPORT_SYMBOL_GPL(__bpf_prog_free); | |
139 | ||
b954d834 | 140 | #ifdef CONFIG_BPF_JIT |
738cbe72 DB |
141 | struct bpf_binary_header * |
142 | bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr, | |
143 | unsigned int alignment, | |
144 | bpf_jit_fill_hole_t bpf_fill_ill_insns) | |
145 | { | |
146 | struct bpf_binary_header *hdr; | |
147 | unsigned int size, hole, start; | |
148 | ||
149 | /* Most of BPF filters are really small, but if some of them | |
150 | * fill a page, allow at least 128 extra bytes to insert a | |
151 | * random section of illegal instructions. | |
152 | */ | |
153 | size = round_up(proglen + sizeof(*hdr) + 128, PAGE_SIZE); | |
154 | hdr = module_alloc(size); | |
155 | if (hdr == NULL) | |
156 | return NULL; | |
157 | ||
158 | /* Fill space with illegal/arch-dep instructions. */ | |
159 | bpf_fill_ill_insns(hdr, size); | |
160 | ||
161 | hdr->pages = size / PAGE_SIZE; | |
162 | hole = min_t(unsigned int, size - (proglen + sizeof(*hdr)), | |
163 | PAGE_SIZE - sizeof(*hdr)); | |
164 | start = (prandom_u32() % hole) & ~(alignment - 1); | |
165 | ||
166 | /* Leave a random number of instructions before BPF code. */ | |
167 | *image_ptr = &hdr->image[start]; | |
168 | ||
169 | return hdr; | |
170 | } | |
171 | ||
172 | void bpf_jit_binary_free(struct bpf_binary_header *hdr) | |
173 | { | |
be1f221c | 174 | module_memfree(hdr); |
738cbe72 | 175 | } |
b954d834 | 176 | #endif /* CONFIG_BPF_JIT */ |
738cbe72 | 177 | |
f5bffecd AS |
178 | /* Base function for offset calculation. Needs to go into .text section, |
179 | * therefore keeping it non-static as well; will also be used by JITs | |
180 | * anyway later on, so do not let the compiler omit it. | |
181 | */ | |
182 | noinline u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5) | |
183 | { | |
184 | return 0; | |
185 | } | |
4d9c5c53 | 186 | EXPORT_SYMBOL_GPL(__bpf_call_base); |
f5bffecd AS |
187 | |
188 | /** | |
7ae457c1 AS |
189 | * __bpf_prog_run - run eBPF program on a given context |
190 | * @ctx: is the data we are operating on | |
191 | * @insn: is the array of eBPF instructions | |
f5bffecd | 192 | * |
7ae457c1 | 193 | * Decode and execute eBPF instructions. |
f5bffecd | 194 | */ |
7ae457c1 | 195 | static unsigned int __bpf_prog_run(void *ctx, const struct bpf_insn *insn) |
f5bffecd AS |
196 | { |
197 | u64 stack[MAX_BPF_STACK / sizeof(u64)]; | |
198 | u64 regs[MAX_BPF_REG], tmp; | |
199 | static const void *jumptable[256] = { | |
200 | [0 ... 255] = &&default_label, | |
201 | /* Now overwrite non-defaults ... */ | |
202 | /* 32 bit ALU operations */ | |
203 | [BPF_ALU | BPF_ADD | BPF_X] = &&ALU_ADD_X, | |
204 | [BPF_ALU | BPF_ADD | BPF_K] = &&ALU_ADD_K, | |
205 | [BPF_ALU | BPF_SUB | BPF_X] = &&ALU_SUB_X, | |
206 | [BPF_ALU | BPF_SUB | BPF_K] = &&ALU_SUB_K, | |
207 | [BPF_ALU | BPF_AND | BPF_X] = &&ALU_AND_X, | |
208 | [BPF_ALU | BPF_AND | BPF_K] = &&ALU_AND_K, | |
209 | [BPF_ALU | BPF_OR | BPF_X] = &&ALU_OR_X, | |
210 | [BPF_ALU | BPF_OR | BPF_K] = &&ALU_OR_K, | |
211 | [BPF_ALU | BPF_LSH | BPF_X] = &&ALU_LSH_X, | |
212 | [BPF_ALU | BPF_LSH | BPF_K] = &&ALU_LSH_K, | |
213 | [BPF_ALU | BPF_RSH | BPF_X] = &&ALU_RSH_X, | |
214 | [BPF_ALU | BPF_RSH | BPF_K] = &&ALU_RSH_K, | |
215 | [BPF_ALU | BPF_XOR | BPF_X] = &&ALU_XOR_X, | |
216 | [BPF_ALU | BPF_XOR | BPF_K] = &&ALU_XOR_K, | |
217 | [BPF_ALU | BPF_MUL | BPF_X] = &&ALU_MUL_X, | |
218 | [BPF_ALU | BPF_MUL | BPF_K] = &&ALU_MUL_K, | |
219 | [BPF_ALU | BPF_MOV | BPF_X] = &&ALU_MOV_X, | |
220 | [BPF_ALU | BPF_MOV | BPF_K] = &&ALU_MOV_K, | |
221 | [BPF_ALU | BPF_DIV | BPF_X] = &&ALU_DIV_X, | |
222 | [BPF_ALU | BPF_DIV | BPF_K] = &&ALU_DIV_K, | |
223 | [BPF_ALU | BPF_MOD | BPF_X] = &&ALU_MOD_X, | |
224 | [BPF_ALU | BPF_MOD | BPF_K] = &&ALU_MOD_K, | |
225 | [BPF_ALU | BPF_NEG] = &&ALU_NEG, | |
226 | [BPF_ALU | BPF_END | BPF_TO_BE] = &&ALU_END_TO_BE, | |
227 | [BPF_ALU | BPF_END | BPF_TO_LE] = &&ALU_END_TO_LE, | |
228 | /* 64 bit ALU operations */ | |
229 | [BPF_ALU64 | BPF_ADD | BPF_X] = &&ALU64_ADD_X, | |
230 | [BPF_ALU64 | BPF_ADD | BPF_K] = &&ALU64_ADD_K, | |
231 | [BPF_ALU64 | BPF_SUB | BPF_X] = &&ALU64_SUB_X, | |
232 | [BPF_ALU64 | BPF_SUB | BPF_K] = &&ALU64_SUB_K, | |
233 | [BPF_ALU64 | BPF_AND | BPF_X] = &&ALU64_AND_X, | |
234 | [BPF_ALU64 | BPF_AND | BPF_K] = &&ALU64_AND_K, | |
235 | [BPF_ALU64 | BPF_OR | BPF_X] = &&ALU64_OR_X, | |
236 | [BPF_ALU64 | BPF_OR | BPF_K] = &&ALU64_OR_K, | |
237 | [BPF_ALU64 | BPF_LSH | BPF_X] = &&ALU64_LSH_X, | |
238 | [BPF_ALU64 | BPF_LSH | BPF_K] = &&ALU64_LSH_K, | |
239 | [BPF_ALU64 | BPF_RSH | BPF_X] = &&ALU64_RSH_X, | |
240 | [BPF_ALU64 | BPF_RSH | BPF_K] = &&ALU64_RSH_K, | |
241 | [BPF_ALU64 | BPF_XOR | BPF_X] = &&ALU64_XOR_X, | |
242 | [BPF_ALU64 | BPF_XOR | BPF_K] = &&ALU64_XOR_K, | |
243 | [BPF_ALU64 | BPF_MUL | BPF_X] = &&ALU64_MUL_X, | |
244 | [BPF_ALU64 | BPF_MUL | BPF_K] = &&ALU64_MUL_K, | |
245 | [BPF_ALU64 | BPF_MOV | BPF_X] = &&ALU64_MOV_X, | |
246 | [BPF_ALU64 | BPF_MOV | BPF_K] = &&ALU64_MOV_K, | |
247 | [BPF_ALU64 | BPF_ARSH | BPF_X] = &&ALU64_ARSH_X, | |
248 | [BPF_ALU64 | BPF_ARSH | BPF_K] = &&ALU64_ARSH_K, | |
249 | [BPF_ALU64 | BPF_DIV | BPF_X] = &&ALU64_DIV_X, | |
250 | [BPF_ALU64 | BPF_DIV | BPF_K] = &&ALU64_DIV_K, | |
251 | [BPF_ALU64 | BPF_MOD | BPF_X] = &&ALU64_MOD_X, | |
252 | [BPF_ALU64 | BPF_MOD | BPF_K] = &&ALU64_MOD_K, | |
253 | [BPF_ALU64 | BPF_NEG] = &&ALU64_NEG, | |
254 | /* Call instruction */ | |
255 | [BPF_JMP | BPF_CALL] = &&JMP_CALL, | |
04fd61ab | 256 | [BPF_JMP | BPF_CALL | BPF_X] = &&JMP_TAIL_CALL, |
f5bffecd AS |
257 | /* Jumps */ |
258 | [BPF_JMP | BPF_JA] = &&JMP_JA, | |
259 | [BPF_JMP | BPF_JEQ | BPF_X] = &&JMP_JEQ_X, | |
260 | [BPF_JMP | BPF_JEQ | BPF_K] = &&JMP_JEQ_K, | |
261 | [BPF_JMP | BPF_JNE | BPF_X] = &&JMP_JNE_X, | |
262 | [BPF_JMP | BPF_JNE | BPF_K] = &&JMP_JNE_K, | |
263 | [BPF_JMP | BPF_JGT | BPF_X] = &&JMP_JGT_X, | |
264 | [BPF_JMP | BPF_JGT | BPF_K] = &&JMP_JGT_K, | |
265 | [BPF_JMP | BPF_JGE | BPF_X] = &&JMP_JGE_X, | |
266 | [BPF_JMP | BPF_JGE | BPF_K] = &&JMP_JGE_K, | |
267 | [BPF_JMP | BPF_JSGT | BPF_X] = &&JMP_JSGT_X, | |
268 | [BPF_JMP | BPF_JSGT | BPF_K] = &&JMP_JSGT_K, | |
269 | [BPF_JMP | BPF_JSGE | BPF_X] = &&JMP_JSGE_X, | |
270 | [BPF_JMP | BPF_JSGE | BPF_K] = &&JMP_JSGE_K, | |
271 | [BPF_JMP | BPF_JSET | BPF_X] = &&JMP_JSET_X, | |
272 | [BPF_JMP | BPF_JSET | BPF_K] = &&JMP_JSET_K, | |
273 | /* Program return */ | |
274 | [BPF_JMP | BPF_EXIT] = &&JMP_EXIT, | |
275 | /* Store instructions */ | |
276 | [BPF_STX | BPF_MEM | BPF_B] = &&STX_MEM_B, | |
277 | [BPF_STX | BPF_MEM | BPF_H] = &&STX_MEM_H, | |
278 | [BPF_STX | BPF_MEM | BPF_W] = &&STX_MEM_W, | |
279 | [BPF_STX | BPF_MEM | BPF_DW] = &&STX_MEM_DW, | |
280 | [BPF_STX | BPF_XADD | BPF_W] = &&STX_XADD_W, | |
281 | [BPF_STX | BPF_XADD | BPF_DW] = &&STX_XADD_DW, | |
282 | [BPF_ST | BPF_MEM | BPF_B] = &&ST_MEM_B, | |
283 | [BPF_ST | BPF_MEM | BPF_H] = &&ST_MEM_H, | |
284 | [BPF_ST | BPF_MEM | BPF_W] = &&ST_MEM_W, | |
285 | [BPF_ST | BPF_MEM | BPF_DW] = &&ST_MEM_DW, | |
286 | /* Load instructions */ | |
287 | [BPF_LDX | BPF_MEM | BPF_B] = &&LDX_MEM_B, | |
288 | [BPF_LDX | BPF_MEM | BPF_H] = &&LDX_MEM_H, | |
289 | [BPF_LDX | BPF_MEM | BPF_W] = &&LDX_MEM_W, | |
290 | [BPF_LDX | BPF_MEM | BPF_DW] = &&LDX_MEM_DW, | |
291 | [BPF_LD | BPF_ABS | BPF_W] = &&LD_ABS_W, | |
292 | [BPF_LD | BPF_ABS | BPF_H] = &&LD_ABS_H, | |
293 | [BPF_LD | BPF_ABS | BPF_B] = &&LD_ABS_B, | |
294 | [BPF_LD | BPF_IND | BPF_W] = &&LD_IND_W, | |
295 | [BPF_LD | BPF_IND | BPF_H] = &&LD_IND_H, | |
296 | [BPF_LD | BPF_IND | BPF_B] = &&LD_IND_B, | |
02ab695b | 297 | [BPF_LD | BPF_IMM | BPF_DW] = &&LD_IMM_DW, |
f5bffecd | 298 | }; |
04fd61ab | 299 | u32 tail_call_cnt = 0; |
f5bffecd AS |
300 | void *ptr; |
301 | int off; | |
302 | ||
303 | #define CONT ({ insn++; goto select_insn; }) | |
304 | #define CONT_JMP ({ insn++; goto select_insn; }) | |
305 | ||
306 | FP = (u64) (unsigned long) &stack[ARRAY_SIZE(stack)]; | |
307 | ARG1 = (u64) (unsigned long) ctx; | |
308 | ||
309 | /* Registers used in classic BPF programs need to be reset first. */ | |
310 | regs[BPF_REG_A] = 0; | |
311 | regs[BPF_REG_X] = 0; | |
312 | ||
313 | select_insn: | |
314 | goto *jumptable[insn->code]; | |
315 | ||
316 | /* ALU */ | |
317 | #define ALU(OPCODE, OP) \ | |
318 | ALU64_##OPCODE##_X: \ | |
319 | DST = DST OP SRC; \ | |
320 | CONT; \ | |
321 | ALU_##OPCODE##_X: \ | |
322 | DST = (u32) DST OP (u32) SRC; \ | |
323 | CONT; \ | |
324 | ALU64_##OPCODE##_K: \ | |
325 | DST = DST OP IMM; \ | |
326 | CONT; \ | |
327 | ALU_##OPCODE##_K: \ | |
328 | DST = (u32) DST OP (u32) IMM; \ | |
329 | CONT; | |
330 | ||
331 | ALU(ADD, +) | |
332 | ALU(SUB, -) | |
333 | ALU(AND, &) | |
334 | ALU(OR, |) | |
335 | ALU(LSH, <<) | |
336 | ALU(RSH, >>) | |
337 | ALU(XOR, ^) | |
338 | ALU(MUL, *) | |
339 | #undef ALU | |
340 | ALU_NEG: | |
341 | DST = (u32) -DST; | |
342 | CONT; | |
343 | ALU64_NEG: | |
344 | DST = -DST; | |
345 | CONT; | |
346 | ALU_MOV_X: | |
347 | DST = (u32) SRC; | |
348 | CONT; | |
349 | ALU_MOV_K: | |
350 | DST = (u32) IMM; | |
351 | CONT; | |
352 | ALU64_MOV_X: | |
353 | DST = SRC; | |
354 | CONT; | |
355 | ALU64_MOV_K: | |
356 | DST = IMM; | |
357 | CONT; | |
02ab695b AS |
358 | LD_IMM_DW: |
359 | DST = (u64) (u32) insn[0].imm | ((u64) (u32) insn[1].imm) << 32; | |
360 | insn++; | |
361 | CONT; | |
f5bffecd AS |
362 | ALU64_ARSH_X: |
363 | (*(s64 *) &DST) >>= SRC; | |
364 | CONT; | |
365 | ALU64_ARSH_K: | |
366 | (*(s64 *) &DST) >>= IMM; | |
367 | CONT; | |
368 | ALU64_MOD_X: | |
369 | if (unlikely(SRC == 0)) | |
370 | return 0; | |
876a7ae6 AS |
371 | div64_u64_rem(DST, SRC, &tmp); |
372 | DST = tmp; | |
f5bffecd AS |
373 | CONT; |
374 | ALU_MOD_X: | |
375 | if (unlikely(SRC == 0)) | |
376 | return 0; | |
377 | tmp = (u32) DST; | |
378 | DST = do_div(tmp, (u32) SRC); | |
379 | CONT; | |
380 | ALU64_MOD_K: | |
876a7ae6 AS |
381 | div64_u64_rem(DST, IMM, &tmp); |
382 | DST = tmp; | |
f5bffecd AS |
383 | CONT; |
384 | ALU_MOD_K: | |
385 | tmp = (u32) DST; | |
386 | DST = do_div(tmp, (u32) IMM); | |
387 | CONT; | |
388 | ALU64_DIV_X: | |
389 | if (unlikely(SRC == 0)) | |
390 | return 0; | |
876a7ae6 | 391 | DST = div64_u64(DST, SRC); |
f5bffecd AS |
392 | CONT; |
393 | ALU_DIV_X: | |
394 | if (unlikely(SRC == 0)) | |
395 | return 0; | |
396 | tmp = (u32) DST; | |
397 | do_div(tmp, (u32) SRC); | |
398 | DST = (u32) tmp; | |
399 | CONT; | |
400 | ALU64_DIV_K: | |
876a7ae6 | 401 | DST = div64_u64(DST, IMM); |
f5bffecd AS |
402 | CONT; |
403 | ALU_DIV_K: | |
404 | tmp = (u32) DST; | |
405 | do_div(tmp, (u32) IMM); | |
406 | DST = (u32) tmp; | |
407 | CONT; | |
408 | ALU_END_TO_BE: | |
409 | switch (IMM) { | |
410 | case 16: | |
411 | DST = (__force u16) cpu_to_be16(DST); | |
412 | break; | |
413 | case 32: | |
414 | DST = (__force u32) cpu_to_be32(DST); | |
415 | break; | |
416 | case 64: | |
417 | DST = (__force u64) cpu_to_be64(DST); | |
418 | break; | |
419 | } | |
420 | CONT; | |
421 | ALU_END_TO_LE: | |
422 | switch (IMM) { | |
423 | case 16: | |
424 | DST = (__force u16) cpu_to_le16(DST); | |
425 | break; | |
426 | case 32: | |
427 | DST = (__force u32) cpu_to_le32(DST); | |
428 | break; | |
429 | case 64: | |
430 | DST = (__force u64) cpu_to_le64(DST); | |
431 | break; | |
432 | } | |
433 | CONT; | |
434 | ||
435 | /* CALL */ | |
436 | JMP_CALL: | |
437 | /* Function call scratches BPF_R1-BPF_R5 registers, | |
438 | * preserves BPF_R6-BPF_R9, and stores return value | |
439 | * into BPF_R0. | |
440 | */ | |
441 | BPF_R0 = (__bpf_call_base + insn->imm)(BPF_R1, BPF_R2, BPF_R3, | |
442 | BPF_R4, BPF_R5); | |
443 | CONT; | |
444 | ||
04fd61ab AS |
445 | JMP_TAIL_CALL: { |
446 | struct bpf_map *map = (struct bpf_map *) (unsigned long) BPF_R2; | |
447 | struct bpf_array *array = container_of(map, struct bpf_array, map); | |
448 | struct bpf_prog *prog; | |
449 | u64 index = BPF_R3; | |
450 | ||
451 | if (unlikely(index >= array->map.max_entries)) | |
452 | goto out; | |
453 | ||
454 | if (unlikely(tail_call_cnt > MAX_TAIL_CALL_CNT)) | |
455 | goto out; | |
456 | ||
457 | tail_call_cnt++; | |
458 | ||
2a36f0b9 | 459 | prog = READ_ONCE(array->ptrs[index]); |
04fd61ab AS |
460 | if (unlikely(!prog)) |
461 | goto out; | |
462 | ||
c4675f93 DB |
463 | /* ARG1 at this point is guaranteed to point to CTX from |
464 | * the verifier side due to the fact that the tail call is | |
465 | * handeled like a helper, that is, bpf_tail_call_proto, | |
466 | * where arg1_type is ARG_PTR_TO_CTX. | |
467 | */ | |
04fd61ab AS |
468 | insn = prog->insnsi; |
469 | goto select_insn; | |
470 | out: | |
471 | CONT; | |
472 | } | |
f5bffecd AS |
473 | /* JMP */ |
474 | JMP_JA: | |
475 | insn += insn->off; | |
476 | CONT; | |
477 | JMP_JEQ_X: | |
478 | if (DST == SRC) { | |
479 | insn += insn->off; | |
480 | CONT_JMP; | |
481 | } | |
482 | CONT; | |
483 | JMP_JEQ_K: | |
484 | if (DST == IMM) { | |
485 | insn += insn->off; | |
486 | CONT_JMP; | |
487 | } | |
488 | CONT; | |
489 | JMP_JNE_X: | |
490 | if (DST != SRC) { | |
491 | insn += insn->off; | |
492 | CONT_JMP; | |
493 | } | |
494 | CONT; | |
495 | JMP_JNE_K: | |
496 | if (DST != IMM) { | |
497 | insn += insn->off; | |
498 | CONT_JMP; | |
499 | } | |
500 | CONT; | |
501 | JMP_JGT_X: | |
502 | if (DST > SRC) { | |
503 | insn += insn->off; | |
504 | CONT_JMP; | |
505 | } | |
506 | CONT; | |
507 | JMP_JGT_K: | |
508 | if (DST > IMM) { | |
509 | insn += insn->off; | |
510 | CONT_JMP; | |
511 | } | |
512 | CONT; | |
513 | JMP_JGE_X: | |
514 | if (DST >= SRC) { | |
515 | insn += insn->off; | |
516 | CONT_JMP; | |
517 | } | |
518 | CONT; | |
519 | JMP_JGE_K: | |
520 | if (DST >= IMM) { | |
521 | insn += insn->off; | |
522 | CONT_JMP; | |
523 | } | |
524 | CONT; | |
525 | JMP_JSGT_X: | |
526 | if (((s64) DST) > ((s64) SRC)) { | |
527 | insn += insn->off; | |
528 | CONT_JMP; | |
529 | } | |
530 | CONT; | |
531 | JMP_JSGT_K: | |
532 | if (((s64) DST) > ((s64) IMM)) { | |
533 | insn += insn->off; | |
534 | CONT_JMP; | |
535 | } | |
536 | CONT; | |
537 | JMP_JSGE_X: | |
538 | if (((s64) DST) >= ((s64) SRC)) { | |
539 | insn += insn->off; | |
540 | CONT_JMP; | |
541 | } | |
542 | CONT; | |
543 | JMP_JSGE_K: | |
544 | if (((s64) DST) >= ((s64) IMM)) { | |
545 | insn += insn->off; | |
546 | CONT_JMP; | |
547 | } | |
548 | CONT; | |
549 | JMP_JSET_X: | |
550 | if (DST & SRC) { | |
551 | insn += insn->off; | |
552 | CONT_JMP; | |
553 | } | |
554 | CONT; | |
555 | JMP_JSET_K: | |
556 | if (DST & IMM) { | |
557 | insn += insn->off; | |
558 | CONT_JMP; | |
559 | } | |
560 | CONT; | |
561 | JMP_EXIT: | |
562 | return BPF_R0; | |
563 | ||
564 | /* STX and ST and LDX*/ | |
565 | #define LDST(SIZEOP, SIZE) \ | |
566 | STX_MEM_##SIZEOP: \ | |
567 | *(SIZE *)(unsigned long) (DST + insn->off) = SRC; \ | |
568 | CONT; \ | |
569 | ST_MEM_##SIZEOP: \ | |
570 | *(SIZE *)(unsigned long) (DST + insn->off) = IMM; \ | |
571 | CONT; \ | |
572 | LDX_MEM_##SIZEOP: \ | |
573 | DST = *(SIZE *)(unsigned long) (SRC + insn->off); \ | |
574 | CONT; | |
575 | ||
576 | LDST(B, u8) | |
577 | LDST(H, u16) | |
578 | LDST(W, u32) | |
579 | LDST(DW, u64) | |
580 | #undef LDST | |
581 | STX_XADD_W: /* lock xadd *(u32 *)(dst_reg + off16) += src_reg */ | |
582 | atomic_add((u32) SRC, (atomic_t *)(unsigned long) | |
583 | (DST + insn->off)); | |
584 | CONT; | |
585 | STX_XADD_DW: /* lock xadd *(u64 *)(dst_reg + off16) += src_reg */ | |
586 | atomic64_add((u64) SRC, (atomic64_t *)(unsigned long) | |
587 | (DST + insn->off)); | |
588 | CONT; | |
589 | LD_ABS_W: /* BPF_R0 = ntohl(*(u32 *) (skb->data + imm32)) */ | |
590 | off = IMM; | |
591 | load_word: | |
592 | /* BPF_LD + BPD_ABS and BPF_LD + BPF_IND insns are | |
593 | * only appearing in the programs where ctx == | |
594 | * skb. All programs keep 'ctx' in regs[BPF_REG_CTX] | |
8fb575ca | 595 | * == BPF_R6, bpf_convert_filter() saves it in BPF_R6, |
f5bffecd AS |
596 | * internal BPF verifier will check that BPF_R6 == |
597 | * ctx. | |
598 | * | |
599 | * BPF_ABS and BPF_IND are wrappers of function calls, | |
600 | * so they scratch BPF_R1-BPF_R5 registers, preserve | |
601 | * BPF_R6-BPF_R9, and store return value into BPF_R0. | |
602 | * | |
603 | * Implicit input: | |
604 | * ctx == skb == BPF_R6 == CTX | |
605 | * | |
606 | * Explicit input: | |
607 | * SRC == any register | |
608 | * IMM == 32-bit immediate | |
609 | * | |
610 | * Output: | |
611 | * BPF_R0 - 8/16/32-bit skb data converted to cpu endianness | |
612 | */ | |
613 | ||
614 | ptr = bpf_load_pointer((struct sk_buff *) (unsigned long) CTX, off, 4, &tmp); | |
615 | if (likely(ptr != NULL)) { | |
616 | BPF_R0 = get_unaligned_be32(ptr); | |
617 | CONT; | |
618 | } | |
619 | ||
620 | return 0; | |
621 | LD_ABS_H: /* BPF_R0 = ntohs(*(u16 *) (skb->data + imm32)) */ | |
622 | off = IMM; | |
623 | load_half: | |
624 | ptr = bpf_load_pointer((struct sk_buff *) (unsigned long) CTX, off, 2, &tmp); | |
625 | if (likely(ptr != NULL)) { | |
626 | BPF_R0 = get_unaligned_be16(ptr); | |
627 | CONT; | |
628 | } | |
629 | ||
630 | return 0; | |
631 | LD_ABS_B: /* BPF_R0 = *(u8 *) (skb->data + imm32) */ | |
632 | off = IMM; | |
633 | load_byte: | |
634 | ptr = bpf_load_pointer((struct sk_buff *) (unsigned long) CTX, off, 1, &tmp); | |
635 | if (likely(ptr != NULL)) { | |
636 | BPF_R0 = *(u8 *)ptr; | |
637 | CONT; | |
638 | } | |
639 | ||
640 | return 0; | |
641 | LD_IND_W: /* BPF_R0 = ntohl(*(u32 *) (skb->data + src_reg + imm32)) */ | |
642 | off = IMM + SRC; | |
643 | goto load_word; | |
644 | LD_IND_H: /* BPF_R0 = ntohs(*(u16 *) (skb->data + src_reg + imm32)) */ | |
645 | off = IMM + SRC; | |
646 | goto load_half; | |
647 | LD_IND_B: /* BPF_R0 = *(u8 *) (skb->data + src_reg + imm32) */ | |
648 | off = IMM + SRC; | |
649 | goto load_byte; | |
650 | ||
651 | default_label: | |
652 | /* If we ever reach this, we have a bug somewhere. */ | |
653 | WARN_RATELIMIT(1, "unknown opcode %02x\n", insn->code); | |
654 | return 0; | |
655 | } | |
656 | ||
3324b584 DB |
657 | bool bpf_prog_array_compatible(struct bpf_array *array, |
658 | const struct bpf_prog *fp) | |
04fd61ab | 659 | { |
3324b584 DB |
660 | if (!array->owner_prog_type) { |
661 | /* There's no owner yet where we could check for | |
662 | * compatibility. | |
663 | */ | |
04fd61ab AS |
664 | array->owner_prog_type = fp->type; |
665 | array->owner_jited = fp->jited; | |
3324b584 DB |
666 | |
667 | return true; | |
04fd61ab | 668 | } |
3324b584 DB |
669 | |
670 | return array->owner_prog_type == fp->type && | |
671 | array->owner_jited == fp->jited; | |
04fd61ab AS |
672 | } |
673 | ||
3324b584 | 674 | static int bpf_check_tail_call(const struct bpf_prog *fp) |
04fd61ab AS |
675 | { |
676 | struct bpf_prog_aux *aux = fp->aux; | |
677 | int i; | |
678 | ||
679 | for (i = 0; i < aux->used_map_cnt; i++) { | |
3324b584 | 680 | struct bpf_map *map = aux->used_maps[i]; |
04fd61ab | 681 | struct bpf_array *array; |
04fd61ab | 682 | |
04fd61ab AS |
683 | if (map->map_type != BPF_MAP_TYPE_PROG_ARRAY) |
684 | continue; | |
3324b584 | 685 | |
04fd61ab AS |
686 | array = container_of(map, struct bpf_array, map); |
687 | if (!bpf_prog_array_compatible(array, fp)) | |
688 | return -EINVAL; | |
689 | } | |
690 | ||
691 | return 0; | |
692 | } | |
693 | ||
f5bffecd | 694 | /** |
3324b584 | 695 | * bpf_prog_select_runtime - select exec runtime for BPF program |
7ae457c1 | 696 | * @fp: bpf_prog populated with internal BPF program |
f5bffecd | 697 | * |
3324b584 DB |
698 | * Try to JIT eBPF program, if JIT is not available, use interpreter. |
699 | * The BPF program will be executed via BPF_PROG_RUN() macro. | |
f5bffecd | 700 | */ |
04fd61ab | 701 | int bpf_prog_select_runtime(struct bpf_prog *fp) |
f5bffecd | 702 | { |
7ae457c1 | 703 | fp->bpf_func = (void *) __bpf_prog_run; |
f5bffecd | 704 | |
f5bffecd | 705 | bpf_int_jit_compile(fp); |
60a3b225 | 706 | bpf_prog_lock_ro(fp); |
04fd61ab | 707 | |
3324b584 DB |
708 | /* The tail call compatibility check can only be done at |
709 | * this late stage as we need to determine, if we deal | |
710 | * with JITed or non JITed program concatenations and not | |
711 | * all eBPF JITs might immediately support all features. | |
712 | */ | |
713 | return bpf_check_tail_call(fp); | |
f5bffecd | 714 | } |
7ae457c1 | 715 | EXPORT_SYMBOL_GPL(bpf_prog_select_runtime); |
f5bffecd | 716 | |
60a3b225 DB |
717 | static void bpf_prog_free_deferred(struct work_struct *work) |
718 | { | |
09756af4 | 719 | struct bpf_prog_aux *aux; |
60a3b225 | 720 | |
09756af4 AS |
721 | aux = container_of(work, struct bpf_prog_aux, work); |
722 | bpf_jit_free(aux->prog); | |
60a3b225 DB |
723 | } |
724 | ||
725 | /* Free internal BPF program */ | |
7ae457c1 | 726 | void bpf_prog_free(struct bpf_prog *fp) |
f5bffecd | 727 | { |
09756af4 | 728 | struct bpf_prog_aux *aux = fp->aux; |
60a3b225 | 729 | |
09756af4 | 730 | INIT_WORK(&aux->work, bpf_prog_free_deferred); |
09756af4 | 731 | schedule_work(&aux->work); |
f5bffecd | 732 | } |
7ae457c1 | 733 | EXPORT_SYMBOL_GPL(bpf_prog_free); |
f89b7755 | 734 | |
3ad00405 DB |
735 | /* RNG for unpriviledged user space with separated state from prandom_u32(). */ |
736 | static DEFINE_PER_CPU(struct rnd_state, bpf_user_rnd_state); | |
737 | ||
738 | void bpf_user_rnd_init_once(void) | |
739 | { | |
740 | prandom_init_once(&bpf_user_rnd_state); | |
741 | } | |
742 | ||
743 | u64 bpf_user_rnd_u32(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5) | |
744 | { | |
745 | /* Should someone ever have the rather unwise idea to use some | |
746 | * of the registers passed into this function, then note that | |
747 | * this function is called from native eBPF and classic-to-eBPF | |
748 | * transformations. Register assignments from both sides are | |
749 | * different, f.e. classic always sets fn(ctx, A, X) here. | |
750 | */ | |
751 | struct rnd_state *state; | |
752 | u32 res; | |
753 | ||
754 | state = &get_cpu_var(bpf_user_rnd_state); | |
755 | res = prandom_u32_state(state); | |
756 | put_cpu_var(state); | |
757 | ||
758 | return res; | |
759 | } | |
760 | ||
3ba67dab DB |
761 | /* Weak definitions of helper functions in case we don't have bpf syscall. */ |
762 | const struct bpf_func_proto bpf_map_lookup_elem_proto __weak; | |
763 | const struct bpf_func_proto bpf_map_update_elem_proto __weak; | |
764 | const struct bpf_func_proto bpf_map_delete_elem_proto __weak; | |
765 | ||
03e69b50 | 766 | const struct bpf_func_proto bpf_get_prandom_u32_proto __weak; |
c04167ce | 767 | const struct bpf_func_proto bpf_get_smp_processor_id_proto __weak; |
17ca8cbf | 768 | const struct bpf_func_proto bpf_ktime_get_ns_proto __weak; |
ffeedafb AS |
769 | const struct bpf_func_proto bpf_get_current_pid_tgid_proto __weak; |
770 | const struct bpf_func_proto bpf_get_current_uid_gid_proto __weak; | |
771 | const struct bpf_func_proto bpf_get_current_comm_proto __weak; | |
0756ea3e AS |
772 | const struct bpf_func_proto * __weak bpf_get_trace_printk_proto(void) |
773 | { | |
774 | return NULL; | |
775 | } | |
03e69b50 | 776 | |
3324b584 DB |
777 | /* Always built-in helper functions. */ |
778 | const struct bpf_func_proto bpf_tail_call_proto = { | |
779 | .func = NULL, | |
780 | .gpl_only = false, | |
781 | .ret_type = RET_VOID, | |
782 | .arg1_type = ARG_PTR_TO_CTX, | |
783 | .arg2_type = ARG_CONST_MAP_PTR, | |
784 | .arg3_type = ARG_ANYTHING, | |
785 | }; | |
786 | ||
787 | /* For classic BPF JITs that don't implement bpf_int_jit_compile(). */ | |
788 | void __weak bpf_int_jit_compile(struct bpf_prog *prog) | |
789 | { | |
790 | } | |
791 | ||
f89b7755 AS |
792 | /* To execute LD_ABS/LD_IND instructions __bpf_prog_run() may call |
793 | * skb_copy_bits(), so provide a weak definition of it for NET-less config. | |
794 | */ | |
795 | int __weak skb_copy_bits(const struct sk_buff *skb, int offset, void *to, | |
796 | int len) | |
797 | { | |
798 | return -EFAULT; | |
799 | } |