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Commit | Line | Data |
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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 AS |
22 | */ |
23 | #include <linux/filter.h> | |
24 | #include <linux/skbuff.h> | |
60a3b225 | 25 | #include <linux/vmalloc.h> |
f5bffecd AS |
26 | #include <asm/unaligned.h> |
27 | ||
28 | /* Registers */ | |
29 | #define BPF_R0 regs[BPF_REG_0] | |
30 | #define BPF_R1 regs[BPF_REG_1] | |
31 | #define BPF_R2 regs[BPF_REG_2] | |
32 | #define BPF_R3 regs[BPF_REG_3] | |
33 | #define BPF_R4 regs[BPF_REG_4] | |
34 | #define BPF_R5 regs[BPF_REG_5] | |
35 | #define BPF_R6 regs[BPF_REG_6] | |
36 | #define BPF_R7 regs[BPF_REG_7] | |
37 | #define BPF_R8 regs[BPF_REG_8] | |
38 | #define BPF_R9 regs[BPF_REG_9] | |
39 | #define BPF_R10 regs[BPF_REG_10] | |
40 | ||
41 | /* Named registers */ | |
42 | #define DST regs[insn->dst_reg] | |
43 | #define SRC regs[insn->src_reg] | |
44 | #define FP regs[BPF_REG_FP] | |
45 | #define ARG1 regs[BPF_REG_ARG1] | |
46 | #define CTX regs[BPF_REG_CTX] | |
47 | #define IMM insn->imm | |
48 | ||
49 | /* No hurry in this branch | |
50 | * | |
51 | * Exported for the bpf jit load helper. | |
52 | */ | |
53 | void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb, int k, unsigned int size) | |
54 | { | |
55 | u8 *ptr = NULL; | |
56 | ||
57 | if (k >= SKF_NET_OFF) | |
58 | ptr = skb_network_header(skb) + k - SKF_NET_OFF; | |
59 | else if (k >= SKF_LL_OFF) | |
60 | ptr = skb_mac_header(skb) + k - SKF_LL_OFF; | |
61 | if (ptr >= skb->head && ptr + size <= skb_tail_pointer(skb)) | |
62 | return ptr; | |
63 | ||
64 | return NULL; | |
65 | } | |
66 | ||
60a3b225 DB |
67 | struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags) |
68 | { | |
69 | gfp_t gfp_flags = GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO | | |
70 | gfp_extra_flags; | |
71 | struct bpf_work_struct *ws; | |
72 | struct bpf_prog *fp; | |
73 | ||
74 | size = round_up(size, PAGE_SIZE); | |
75 | fp = __vmalloc(size, gfp_flags, PAGE_KERNEL); | |
76 | if (fp == NULL) | |
77 | return NULL; | |
78 | ||
79 | ws = kmalloc(sizeof(*ws), GFP_KERNEL | gfp_extra_flags); | |
80 | if (ws == NULL) { | |
81 | vfree(fp); | |
82 | return NULL; | |
83 | } | |
84 | ||
85 | fp->pages = size / PAGE_SIZE; | |
86 | fp->work = ws; | |
87 | ||
88 | return fp; | |
89 | } | |
90 | EXPORT_SYMBOL_GPL(bpf_prog_alloc); | |
91 | ||
92 | struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size, | |
93 | gfp_t gfp_extra_flags) | |
94 | { | |
95 | gfp_t gfp_flags = GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO | | |
96 | gfp_extra_flags; | |
97 | struct bpf_prog *fp; | |
98 | ||
99 | BUG_ON(fp_old == NULL); | |
100 | ||
101 | size = round_up(size, PAGE_SIZE); | |
102 | if (size <= fp_old->pages * PAGE_SIZE) | |
103 | return fp_old; | |
104 | ||
105 | fp = __vmalloc(size, gfp_flags, PAGE_KERNEL); | |
106 | if (fp != NULL) { | |
107 | memcpy(fp, fp_old, fp_old->pages * PAGE_SIZE); | |
108 | fp->pages = size / PAGE_SIZE; | |
109 | ||
110 | /* We keep fp->work from fp_old around in the new | |
111 | * reallocated structure. | |
112 | */ | |
113 | fp_old->work = NULL; | |
114 | __bpf_prog_free(fp_old); | |
115 | } | |
116 | ||
117 | return fp; | |
118 | } | |
119 | EXPORT_SYMBOL_GPL(bpf_prog_realloc); | |
120 | ||
121 | void __bpf_prog_free(struct bpf_prog *fp) | |
122 | { | |
123 | kfree(fp->work); | |
124 | vfree(fp); | |
125 | } | |
126 | EXPORT_SYMBOL_GPL(__bpf_prog_free); | |
127 | ||
f5bffecd AS |
128 | /* Base function for offset calculation. Needs to go into .text section, |
129 | * therefore keeping it non-static as well; will also be used by JITs | |
130 | * anyway later on, so do not let the compiler omit it. | |
131 | */ | |
132 | noinline u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5) | |
133 | { | |
134 | return 0; | |
135 | } | |
136 | ||
137 | /** | |
7ae457c1 AS |
138 | * __bpf_prog_run - run eBPF program on a given context |
139 | * @ctx: is the data we are operating on | |
140 | * @insn: is the array of eBPF instructions | |
f5bffecd | 141 | * |
7ae457c1 | 142 | * Decode and execute eBPF instructions. |
f5bffecd | 143 | */ |
7ae457c1 | 144 | static unsigned int __bpf_prog_run(void *ctx, const struct bpf_insn *insn) |
f5bffecd AS |
145 | { |
146 | u64 stack[MAX_BPF_STACK / sizeof(u64)]; | |
147 | u64 regs[MAX_BPF_REG], tmp; | |
148 | static const void *jumptable[256] = { | |
149 | [0 ... 255] = &&default_label, | |
150 | /* Now overwrite non-defaults ... */ | |
151 | /* 32 bit ALU operations */ | |
152 | [BPF_ALU | BPF_ADD | BPF_X] = &&ALU_ADD_X, | |
153 | [BPF_ALU | BPF_ADD | BPF_K] = &&ALU_ADD_K, | |
154 | [BPF_ALU | BPF_SUB | BPF_X] = &&ALU_SUB_X, | |
155 | [BPF_ALU | BPF_SUB | BPF_K] = &&ALU_SUB_K, | |
156 | [BPF_ALU | BPF_AND | BPF_X] = &&ALU_AND_X, | |
157 | [BPF_ALU | BPF_AND | BPF_K] = &&ALU_AND_K, | |
158 | [BPF_ALU | BPF_OR | BPF_X] = &&ALU_OR_X, | |
159 | [BPF_ALU | BPF_OR | BPF_K] = &&ALU_OR_K, | |
160 | [BPF_ALU | BPF_LSH | BPF_X] = &&ALU_LSH_X, | |
161 | [BPF_ALU | BPF_LSH | BPF_K] = &&ALU_LSH_K, | |
162 | [BPF_ALU | BPF_RSH | BPF_X] = &&ALU_RSH_X, | |
163 | [BPF_ALU | BPF_RSH | BPF_K] = &&ALU_RSH_K, | |
164 | [BPF_ALU | BPF_XOR | BPF_X] = &&ALU_XOR_X, | |
165 | [BPF_ALU | BPF_XOR | BPF_K] = &&ALU_XOR_K, | |
166 | [BPF_ALU | BPF_MUL | BPF_X] = &&ALU_MUL_X, | |
167 | [BPF_ALU | BPF_MUL | BPF_K] = &&ALU_MUL_K, | |
168 | [BPF_ALU | BPF_MOV | BPF_X] = &&ALU_MOV_X, | |
169 | [BPF_ALU | BPF_MOV | BPF_K] = &&ALU_MOV_K, | |
170 | [BPF_ALU | BPF_DIV | BPF_X] = &&ALU_DIV_X, | |
171 | [BPF_ALU | BPF_DIV | BPF_K] = &&ALU_DIV_K, | |
172 | [BPF_ALU | BPF_MOD | BPF_X] = &&ALU_MOD_X, | |
173 | [BPF_ALU | BPF_MOD | BPF_K] = &&ALU_MOD_K, | |
174 | [BPF_ALU | BPF_NEG] = &&ALU_NEG, | |
175 | [BPF_ALU | BPF_END | BPF_TO_BE] = &&ALU_END_TO_BE, | |
176 | [BPF_ALU | BPF_END | BPF_TO_LE] = &&ALU_END_TO_LE, | |
177 | /* 64 bit ALU operations */ | |
178 | [BPF_ALU64 | BPF_ADD | BPF_X] = &&ALU64_ADD_X, | |
179 | [BPF_ALU64 | BPF_ADD | BPF_K] = &&ALU64_ADD_K, | |
180 | [BPF_ALU64 | BPF_SUB | BPF_X] = &&ALU64_SUB_X, | |
181 | [BPF_ALU64 | BPF_SUB | BPF_K] = &&ALU64_SUB_K, | |
182 | [BPF_ALU64 | BPF_AND | BPF_X] = &&ALU64_AND_X, | |
183 | [BPF_ALU64 | BPF_AND | BPF_K] = &&ALU64_AND_K, | |
184 | [BPF_ALU64 | BPF_OR | BPF_X] = &&ALU64_OR_X, | |
185 | [BPF_ALU64 | BPF_OR | BPF_K] = &&ALU64_OR_K, | |
186 | [BPF_ALU64 | BPF_LSH | BPF_X] = &&ALU64_LSH_X, | |
187 | [BPF_ALU64 | BPF_LSH | BPF_K] = &&ALU64_LSH_K, | |
188 | [BPF_ALU64 | BPF_RSH | BPF_X] = &&ALU64_RSH_X, | |
189 | [BPF_ALU64 | BPF_RSH | BPF_K] = &&ALU64_RSH_K, | |
190 | [BPF_ALU64 | BPF_XOR | BPF_X] = &&ALU64_XOR_X, | |
191 | [BPF_ALU64 | BPF_XOR | BPF_K] = &&ALU64_XOR_K, | |
192 | [BPF_ALU64 | BPF_MUL | BPF_X] = &&ALU64_MUL_X, | |
193 | [BPF_ALU64 | BPF_MUL | BPF_K] = &&ALU64_MUL_K, | |
194 | [BPF_ALU64 | BPF_MOV | BPF_X] = &&ALU64_MOV_X, | |
195 | [BPF_ALU64 | BPF_MOV | BPF_K] = &&ALU64_MOV_K, | |
196 | [BPF_ALU64 | BPF_ARSH | BPF_X] = &&ALU64_ARSH_X, | |
197 | [BPF_ALU64 | BPF_ARSH | BPF_K] = &&ALU64_ARSH_K, | |
198 | [BPF_ALU64 | BPF_DIV | BPF_X] = &&ALU64_DIV_X, | |
199 | [BPF_ALU64 | BPF_DIV | BPF_K] = &&ALU64_DIV_K, | |
200 | [BPF_ALU64 | BPF_MOD | BPF_X] = &&ALU64_MOD_X, | |
201 | [BPF_ALU64 | BPF_MOD | BPF_K] = &&ALU64_MOD_K, | |
202 | [BPF_ALU64 | BPF_NEG] = &&ALU64_NEG, | |
203 | /* Call instruction */ | |
204 | [BPF_JMP | BPF_CALL] = &&JMP_CALL, | |
205 | /* Jumps */ | |
206 | [BPF_JMP | BPF_JA] = &&JMP_JA, | |
207 | [BPF_JMP | BPF_JEQ | BPF_X] = &&JMP_JEQ_X, | |
208 | [BPF_JMP | BPF_JEQ | BPF_K] = &&JMP_JEQ_K, | |
209 | [BPF_JMP | BPF_JNE | BPF_X] = &&JMP_JNE_X, | |
210 | [BPF_JMP | BPF_JNE | BPF_K] = &&JMP_JNE_K, | |
211 | [BPF_JMP | BPF_JGT | BPF_X] = &&JMP_JGT_X, | |
212 | [BPF_JMP | BPF_JGT | BPF_K] = &&JMP_JGT_K, | |
213 | [BPF_JMP | BPF_JGE | BPF_X] = &&JMP_JGE_X, | |
214 | [BPF_JMP | BPF_JGE | BPF_K] = &&JMP_JGE_K, | |
215 | [BPF_JMP | BPF_JSGT | BPF_X] = &&JMP_JSGT_X, | |
216 | [BPF_JMP | BPF_JSGT | BPF_K] = &&JMP_JSGT_K, | |
217 | [BPF_JMP | BPF_JSGE | BPF_X] = &&JMP_JSGE_X, | |
218 | [BPF_JMP | BPF_JSGE | BPF_K] = &&JMP_JSGE_K, | |
219 | [BPF_JMP | BPF_JSET | BPF_X] = &&JMP_JSET_X, | |
220 | [BPF_JMP | BPF_JSET | BPF_K] = &&JMP_JSET_K, | |
221 | /* Program return */ | |
222 | [BPF_JMP | BPF_EXIT] = &&JMP_EXIT, | |
223 | /* Store instructions */ | |
224 | [BPF_STX | BPF_MEM | BPF_B] = &&STX_MEM_B, | |
225 | [BPF_STX | BPF_MEM | BPF_H] = &&STX_MEM_H, | |
226 | [BPF_STX | BPF_MEM | BPF_W] = &&STX_MEM_W, | |
227 | [BPF_STX | BPF_MEM | BPF_DW] = &&STX_MEM_DW, | |
228 | [BPF_STX | BPF_XADD | BPF_W] = &&STX_XADD_W, | |
229 | [BPF_STX | BPF_XADD | BPF_DW] = &&STX_XADD_DW, | |
230 | [BPF_ST | BPF_MEM | BPF_B] = &&ST_MEM_B, | |
231 | [BPF_ST | BPF_MEM | BPF_H] = &&ST_MEM_H, | |
232 | [BPF_ST | BPF_MEM | BPF_W] = &&ST_MEM_W, | |
233 | [BPF_ST | BPF_MEM | BPF_DW] = &&ST_MEM_DW, | |
234 | /* Load instructions */ | |
235 | [BPF_LDX | BPF_MEM | BPF_B] = &&LDX_MEM_B, | |
236 | [BPF_LDX | BPF_MEM | BPF_H] = &&LDX_MEM_H, | |
237 | [BPF_LDX | BPF_MEM | BPF_W] = &&LDX_MEM_W, | |
238 | [BPF_LDX | BPF_MEM | BPF_DW] = &&LDX_MEM_DW, | |
239 | [BPF_LD | BPF_ABS | BPF_W] = &&LD_ABS_W, | |
240 | [BPF_LD | BPF_ABS | BPF_H] = &&LD_ABS_H, | |
241 | [BPF_LD | BPF_ABS | BPF_B] = &&LD_ABS_B, | |
242 | [BPF_LD | BPF_IND | BPF_W] = &&LD_IND_W, | |
243 | [BPF_LD | BPF_IND | BPF_H] = &&LD_IND_H, | |
244 | [BPF_LD | BPF_IND | BPF_B] = &&LD_IND_B, | |
245 | }; | |
246 | void *ptr; | |
247 | int off; | |
248 | ||
249 | #define CONT ({ insn++; goto select_insn; }) | |
250 | #define CONT_JMP ({ insn++; goto select_insn; }) | |
251 | ||
252 | FP = (u64) (unsigned long) &stack[ARRAY_SIZE(stack)]; | |
253 | ARG1 = (u64) (unsigned long) ctx; | |
254 | ||
255 | /* Registers used in classic BPF programs need to be reset first. */ | |
256 | regs[BPF_REG_A] = 0; | |
257 | regs[BPF_REG_X] = 0; | |
258 | ||
259 | select_insn: | |
260 | goto *jumptable[insn->code]; | |
261 | ||
262 | /* ALU */ | |
263 | #define ALU(OPCODE, OP) \ | |
264 | ALU64_##OPCODE##_X: \ | |
265 | DST = DST OP SRC; \ | |
266 | CONT; \ | |
267 | ALU_##OPCODE##_X: \ | |
268 | DST = (u32) DST OP (u32) SRC; \ | |
269 | CONT; \ | |
270 | ALU64_##OPCODE##_K: \ | |
271 | DST = DST OP IMM; \ | |
272 | CONT; \ | |
273 | ALU_##OPCODE##_K: \ | |
274 | DST = (u32) DST OP (u32) IMM; \ | |
275 | CONT; | |
276 | ||
277 | ALU(ADD, +) | |
278 | ALU(SUB, -) | |
279 | ALU(AND, &) | |
280 | ALU(OR, |) | |
281 | ALU(LSH, <<) | |
282 | ALU(RSH, >>) | |
283 | ALU(XOR, ^) | |
284 | ALU(MUL, *) | |
285 | #undef ALU | |
286 | ALU_NEG: | |
287 | DST = (u32) -DST; | |
288 | CONT; | |
289 | ALU64_NEG: | |
290 | DST = -DST; | |
291 | CONT; | |
292 | ALU_MOV_X: | |
293 | DST = (u32) SRC; | |
294 | CONT; | |
295 | ALU_MOV_K: | |
296 | DST = (u32) IMM; | |
297 | CONT; | |
298 | ALU64_MOV_X: | |
299 | DST = SRC; | |
300 | CONT; | |
301 | ALU64_MOV_K: | |
302 | DST = IMM; | |
303 | CONT; | |
304 | ALU64_ARSH_X: | |
305 | (*(s64 *) &DST) >>= SRC; | |
306 | CONT; | |
307 | ALU64_ARSH_K: | |
308 | (*(s64 *) &DST) >>= IMM; | |
309 | CONT; | |
310 | ALU64_MOD_X: | |
311 | if (unlikely(SRC == 0)) | |
312 | return 0; | |
313 | tmp = DST; | |
314 | DST = do_div(tmp, SRC); | |
315 | CONT; | |
316 | ALU_MOD_X: | |
317 | if (unlikely(SRC == 0)) | |
318 | return 0; | |
319 | tmp = (u32) DST; | |
320 | DST = do_div(tmp, (u32) SRC); | |
321 | CONT; | |
322 | ALU64_MOD_K: | |
323 | tmp = DST; | |
324 | DST = do_div(tmp, IMM); | |
325 | CONT; | |
326 | ALU_MOD_K: | |
327 | tmp = (u32) DST; | |
328 | DST = do_div(tmp, (u32) IMM); | |
329 | CONT; | |
330 | ALU64_DIV_X: | |
331 | if (unlikely(SRC == 0)) | |
332 | return 0; | |
333 | do_div(DST, SRC); | |
334 | CONT; | |
335 | ALU_DIV_X: | |
336 | if (unlikely(SRC == 0)) | |
337 | return 0; | |
338 | tmp = (u32) DST; | |
339 | do_div(tmp, (u32) SRC); | |
340 | DST = (u32) tmp; | |
341 | CONT; | |
342 | ALU64_DIV_K: | |
343 | do_div(DST, IMM); | |
344 | CONT; | |
345 | ALU_DIV_K: | |
346 | tmp = (u32) DST; | |
347 | do_div(tmp, (u32) IMM); | |
348 | DST = (u32) tmp; | |
349 | CONT; | |
350 | ALU_END_TO_BE: | |
351 | switch (IMM) { | |
352 | case 16: | |
353 | DST = (__force u16) cpu_to_be16(DST); | |
354 | break; | |
355 | case 32: | |
356 | DST = (__force u32) cpu_to_be32(DST); | |
357 | break; | |
358 | case 64: | |
359 | DST = (__force u64) cpu_to_be64(DST); | |
360 | break; | |
361 | } | |
362 | CONT; | |
363 | ALU_END_TO_LE: | |
364 | switch (IMM) { | |
365 | case 16: | |
366 | DST = (__force u16) cpu_to_le16(DST); | |
367 | break; | |
368 | case 32: | |
369 | DST = (__force u32) cpu_to_le32(DST); | |
370 | break; | |
371 | case 64: | |
372 | DST = (__force u64) cpu_to_le64(DST); | |
373 | break; | |
374 | } | |
375 | CONT; | |
376 | ||
377 | /* CALL */ | |
378 | JMP_CALL: | |
379 | /* Function call scratches BPF_R1-BPF_R5 registers, | |
380 | * preserves BPF_R6-BPF_R9, and stores return value | |
381 | * into BPF_R0. | |
382 | */ | |
383 | BPF_R0 = (__bpf_call_base + insn->imm)(BPF_R1, BPF_R2, BPF_R3, | |
384 | BPF_R4, BPF_R5); | |
385 | CONT; | |
386 | ||
387 | /* JMP */ | |
388 | JMP_JA: | |
389 | insn += insn->off; | |
390 | CONT; | |
391 | JMP_JEQ_X: | |
392 | if (DST == SRC) { | |
393 | insn += insn->off; | |
394 | CONT_JMP; | |
395 | } | |
396 | CONT; | |
397 | JMP_JEQ_K: | |
398 | if (DST == IMM) { | |
399 | insn += insn->off; | |
400 | CONT_JMP; | |
401 | } | |
402 | CONT; | |
403 | JMP_JNE_X: | |
404 | if (DST != SRC) { | |
405 | insn += insn->off; | |
406 | CONT_JMP; | |
407 | } | |
408 | CONT; | |
409 | JMP_JNE_K: | |
410 | if (DST != IMM) { | |
411 | insn += insn->off; | |
412 | CONT_JMP; | |
413 | } | |
414 | CONT; | |
415 | JMP_JGT_X: | |
416 | if (DST > SRC) { | |
417 | insn += insn->off; | |
418 | CONT_JMP; | |
419 | } | |
420 | CONT; | |
421 | JMP_JGT_K: | |
422 | if (DST > IMM) { | |
423 | insn += insn->off; | |
424 | CONT_JMP; | |
425 | } | |
426 | CONT; | |
427 | JMP_JGE_X: | |
428 | if (DST >= SRC) { | |
429 | insn += insn->off; | |
430 | CONT_JMP; | |
431 | } | |
432 | CONT; | |
433 | JMP_JGE_K: | |
434 | if (DST >= IMM) { | |
435 | insn += insn->off; | |
436 | CONT_JMP; | |
437 | } | |
438 | CONT; | |
439 | JMP_JSGT_X: | |
440 | if (((s64) DST) > ((s64) SRC)) { | |
441 | insn += insn->off; | |
442 | CONT_JMP; | |
443 | } | |
444 | CONT; | |
445 | JMP_JSGT_K: | |
446 | if (((s64) DST) > ((s64) IMM)) { | |
447 | insn += insn->off; | |
448 | CONT_JMP; | |
449 | } | |
450 | CONT; | |
451 | JMP_JSGE_X: | |
452 | if (((s64) DST) >= ((s64) SRC)) { | |
453 | insn += insn->off; | |
454 | CONT_JMP; | |
455 | } | |
456 | CONT; | |
457 | JMP_JSGE_K: | |
458 | if (((s64) DST) >= ((s64) IMM)) { | |
459 | insn += insn->off; | |
460 | CONT_JMP; | |
461 | } | |
462 | CONT; | |
463 | JMP_JSET_X: | |
464 | if (DST & SRC) { | |
465 | insn += insn->off; | |
466 | CONT_JMP; | |
467 | } | |
468 | CONT; | |
469 | JMP_JSET_K: | |
470 | if (DST & IMM) { | |
471 | insn += insn->off; | |
472 | CONT_JMP; | |
473 | } | |
474 | CONT; | |
475 | JMP_EXIT: | |
476 | return BPF_R0; | |
477 | ||
478 | /* STX and ST and LDX*/ | |
479 | #define LDST(SIZEOP, SIZE) \ | |
480 | STX_MEM_##SIZEOP: \ | |
481 | *(SIZE *)(unsigned long) (DST + insn->off) = SRC; \ | |
482 | CONT; \ | |
483 | ST_MEM_##SIZEOP: \ | |
484 | *(SIZE *)(unsigned long) (DST + insn->off) = IMM; \ | |
485 | CONT; \ | |
486 | LDX_MEM_##SIZEOP: \ | |
487 | DST = *(SIZE *)(unsigned long) (SRC + insn->off); \ | |
488 | CONT; | |
489 | ||
490 | LDST(B, u8) | |
491 | LDST(H, u16) | |
492 | LDST(W, u32) | |
493 | LDST(DW, u64) | |
494 | #undef LDST | |
495 | STX_XADD_W: /* lock xadd *(u32 *)(dst_reg + off16) += src_reg */ | |
496 | atomic_add((u32) SRC, (atomic_t *)(unsigned long) | |
497 | (DST + insn->off)); | |
498 | CONT; | |
499 | STX_XADD_DW: /* lock xadd *(u64 *)(dst_reg + off16) += src_reg */ | |
500 | atomic64_add((u64) SRC, (atomic64_t *)(unsigned long) | |
501 | (DST + insn->off)); | |
502 | CONT; | |
503 | LD_ABS_W: /* BPF_R0 = ntohl(*(u32 *) (skb->data + imm32)) */ | |
504 | off = IMM; | |
505 | load_word: | |
506 | /* BPF_LD + BPD_ABS and BPF_LD + BPF_IND insns are | |
507 | * only appearing in the programs where ctx == | |
508 | * skb. All programs keep 'ctx' in regs[BPF_REG_CTX] | |
8fb575ca | 509 | * == BPF_R6, bpf_convert_filter() saves it in BPF_R6, |
f5bffecd AS |
510 | * internal BPF verifier will check that BPF_R6 == |
511 | * ctx. | |
512 | * | |
513 | * BPF_ABS and BPF_IND are wrappers of function calls, | |
514 | * so they scratch BPF_R1-BPF_R5 registers, preserve | |
515 | * BPF_R6-BPF_R9, and store return value into BPF_R0. | |
516 | * | |
517 | * Implicit input: | |
518 | * ctx == skb == BPF_R6 == CTX | |
519 | * | |
520 | * Explicit input: | |
521 | * SRC == any register | |
522 | * IMM == 32-bit immediate | |
523 | * | |
524 | * Output: | |
525 | * BPF_R0 - 8/16/32-bit skb data converted to cpu endianness | |
526 | */ | |
527 | ||
528 | ptr = bpf_load_pointer((struct sk_buff *) (unsigned long) CTX, off, 4, &tmp); | |
529 | if (likely(ptr != NULL)) { | |
530 | BPF_R0 = get_unaligned_be32(ptr); | |
531 | CONT; | |
532 | } | |
533 | ||
534 | return 0; | |
535 | LD_ABS_H: /* BPF_R0 = ntohs(*(u16 *) (skb->data + imm32)) */ | |
536 | off = IMM; | |
537 | load_half: | |
538 | ptr = bpf_load_pointer((struct sk_buff *) (unsigned long) CTX, off, 2, &tmp); | |
539 | if (likely(ptr != NULL)) { | |
540 | BPF_R0 = get_unaligned_be16(ptr); | |
541 | CONT; | |
542 | } | |
543 | ||
544 | return 0; | |
545 | LD_ABS_B: /* BPF_R0 = *(u8 *) (skb->data + imm32) */ | |
546 | off = IMM; | |
547 | load_byte: | |
548 | ptr = bpf_load_pointer((struct sk_buff *) (unsigned long) CTX, off, 1, &tmp); | |
549 | if (likely(ptr != NULL)) { | |
550 | BPF_R0 = *(u8 *)ptr; | |
551 | CONT; | |
552 | } | |
553 | ||
554 | return 0; | |
555 | LD_IND_W: /* BPF_R0 = ntohl(*(u32 *) (skb->data + src_reg + imm32)) */ | |
556 | off = IMM + SRC; | |
557 | goto load_word; | |
558 | LD_IND_H: /* BPF_R0 = ntohs(*(u16 *) (skb->data + src_reg + imm32)) */ | |
559 | off = IMM + SRC; | |
560 | goto load_half; | |
561 | LD_IND_B: /* BPF_R0 = *(u8 *) (skb->data + src_reg + imm32) */ | |
562 | off = IMM + SRC; | |
563 | goto load_byte; | |
564 | ||
565 | default_label: | |
566 | /* If we ever reach this, we have a bug somewhere. */ | |
567 | WARN_RATELIMIT(1, "unknown opcode %02x\n", insn->code); | |
568 | return 0; | |
569 | } | |
570 | ||
7ae457c1 | 571 | void __weak bpf_int_jit_compile(struct bpf_prog *prog) |
f5bffecd AS |
572 | { |
573 | } | |
574 | ||
575 | /** | |
7ae457c1 AS |
576 | * bpf_prog_select_runtime - select execution runtime for BPF program |
577 | * @fp: bpf_prog populated with internal BPF program | |
f5bffecd AS |
578 | * |
579 | * try to JIT internal BPF program, if JIT is not available select interpreter | |
7ae457c1 | 580 | * BPF program will be executed via BPF_PROG_RUN() macro |
f5bffecd | 581 | */ |
7ae457c1 | 582 | void bpf_prog_select_runtime(struct bpf_prog *fp) |
f5bffecd | 583 | { |
7ae457c1 | 584 | fp->bpf_func = (void *) __bpf_prog_run; |
f5bffecd AS |
585 | |
586 | /* Probe if internal BPF can be JITed */ | |
587 | bpf_int_jit_compile(fp); | |
60a3b225 DB |
588 | /* Lock whole bpf_prog as read-only */ |
589 | bpf_prog_lock_ro(fp); | |
f5bffecd | 590 | } |
7ae457c1 | 591 | EXPORT_SYMBOL_GPL(bpf_prog_select_runtime); |
f5bffecd | 592 | |
60a3b225 DB |
593 | static void bpf_prog_free_deferred(struct work_struct *work) |
594 | { | |
595 | struct bpf_work_struct *ws; | |
596 | ||
597 | ws = container_of(work, struct bpf_work_struct, work); | |
598 | bpf_jit_free(ws->prog); | |
599 | } | |
600 | ||
601 | /* Free internal BPF program */ | |
7ae457c1 | 602 | void bpf_prog_free(struct bpf_prog *fp) |
f5bffecd | 603 | { |
60a3b225 DB |
604 | struct bpf_work_struct *ws = fp->work; |
605 | ||
606 | INIT_WORK(&ws->work, bpf_prog_free_deferred); | |
607 | ws->prog = fp; | |
608 | schedule_work(&ws->work); | |
f5bffecd | 609 | } |
7ae457c1 | 610 | EXPORT_SYMBOL_GPL(bpf_prog_free); |