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> | |
f5bffecd AS |
29 | #include <asm/unaligned.h> |
30 | ||
31 | /* Registers */ | |
32 | #define BPF_R0 regs[BPF_REG_0] | |
33 | #define BPF_R1 regs[BPF_REG_1] | |
34 | #define BPF_R2 regs[BPF_REG_2] | |
35 | #define BPF_R3 regs[BPF_REG_3] | |
36 | #define BPF_R4 regs[BPF_REG_4] | |
37 | #define BPF_R5 regs[BPF_REG_5] | |
38 | #define BPF_R6 regs[BPF_REG_6] | |
39 | #define BPF_R7 regs[BPF_REG_7] | |
40 | #define BPF_R8 regs[BPF_REG_8] | |
41 | #define BPF_R9 regs[BPF_REG_9] | |
42 | #define BPF_R10 regs[BPF_REG_10] | |
43 | ||
44 | /* Named registers */ | |
45 | #define DST regs[insn->dst_reg] | |
46 | #define SRC regs[insn->src_reg] | |
47 | #define FP regs[BPF_REG_FP] | |
48 | #define ARG1 regs[BPF_REG_ARG1] | |
49 | #define CTX regs[BPF_REG_CTX] | |
50 | #define IMM insn->imm | |
51 | ||
52 | /* No hurry in this branch | |
53 | * | |
54 | * Exported for the bpf jit load helper. | |
55 | */ | |
56 | void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb, int k, unsigned int size) | |
57 | { | |
58 | u8 *ptr = NULL; | |
59 | ||
60 | if (k >= SKF_NET_OFF) | |
61 | ptr = skb_network_header(skb) + k - SKF_NET_OFF; | |
62 | else if (k >= SKF_LL_OFF) | |
63 | ptr = skb_mac_header(skb) + k - SKF_LL_OFF; | |
64 | if (ptr >= skb->head && ptr + size <= skb_tail_pointer(skb)) | |
65 | return ptr; | |
66 | ||
67 | return NULL; | |
68 | } | |
69 | ||
60a3b225 DB |
70 | struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags) |
71 | { | |
72 | gfp_t gfp_flags = GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO | | |
73 | gfp_extra_flags; | |
74 | struct bpf_work_struct *ws; | |
75 | struct bpf_prog *fp; | |
76 | ||
77 | size = round_up(size, PAGE_SIZE); | |
78 | fp = __vmalloc(size, gfp_flags, PAGE_KERNEL); | |
79 | if (fp == NULL) | |
80 | return NULL; | |
81 | ||
82 | ws = kmalloc(sizeof(*ws), GFP_KERNEL | gfp_extra_flags); | |
83 | if (ws == NULL) { | |
84 | vfree(fp); | |
85 | return NULL; | |
86 | } | |
87 | ||
88 | fp->pages = size / PAGE_SIZE; | |
89 | fp->work = ws; | |
90 | ||
91 | return fp; | |
92 | } | |
93 | EXPORT_SYMBOL_GPL(bpf_prog_alloc); | |
94 | ||
95 | struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size, | |
96 | gfp_t gfp_extra_flags) | |
97 | { | |
98 | gfp_t gfp_flags = GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO | | |
99 | gfp_extra_flags; | |
100 | struct bpf_prog *fp; | |
101 | ||
102 | BUG_ON(fp_old == NULL); | |
103 | ||
104 | size = round_up(size, PAGE_SIZE); | |
105 | if (size <= fp_old->pages * PAGE_SIZE) | |
106 | return fp_old; | |
107 | ||
108 | fp = __vmalloc(size, gfp_flags, PAGE_KERNEL); | |
109 | if (fp != NULL) { | |
110 | memcpy(fp, fp_old, fp_old->pages * PAGE_SIZE); | |
111 | fp->pages = size / PAGE_SIZE; | |
112 | ||
113 | /* We keep fp->work from fp_old around in the new | |
114 | * reallocated structure. | |
115 | */ | |
116 | fp_old->work = NULL; | |
117 | __bpf_prog_free(fp_old); | |
118 | } | |
119 | ||
120 | return fp; | |
121 | } | |
122 | EXPORT_SYMBOL_GPL(bpf_prog_realloc); | |
123 | ||
124 | void __bpf_prog_free(struct bpf_prog *fp) | |
125 | { | |
126 | kfree(fp->work); | |
127 | vfree(fp); | |
128 | } | |
129 | EXPORT_SYMBOL_GPL(__bpf_prog_free); | |
130 | ||
b954d834 | 131 | #ifdef CONFIG_BPF_JIT |
738cbe72 DB |
132 | struct bpf_binary_header * |
133 | bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr, | |
134 | unsigned int alignment, | |
135 | bpf_jit_fill_hole_t bpf_fill_ill_insns) | |
136 | { | |
137 | struct bpf_binary_header *hdr; | |
138 | unsigned int size, hole, start; | |
139 | ||
140 | /* Most of BPF filters are really small, but if some of them | |
141 | * fill a page, allow at least 128 extra bytes to insert a | |
142 | * random section of illegal instructions. | |
143 | */ | |
144 | size = round_up(proglen + sizeof(*hdr) + 128, PAGE_SIZE); | |
145 | hdr = module_alloc(size); | |
146 | if (hdr == NULL) | |
147 | return NULL; | |
148 | ||
149 | /* Fill space with illegal/arch-dep instructions. */ | |
150 | bpf_fill_ill_insns(hdr, size); | |
151 | ||
152 | hdr->pages = size / PAGE_SIZE; | |
153 | hole = min_t(unsigned int, size - (proglen + sizeof(*hdr)), | |
154 | PAGE_SIZE - sizeof(*hdr)); | |
155 | start = (prandom_u32() % hole) & ~(alignment - 1); | |
156 | ||
157 | /* Leave a random number of instructions before BPF code. */ | |
158 | *image_ptr = &hdr->image[start]; | |
159 | ||
160 | return hdr; | |
161 | } | |
162 | ||
163 | void bpf_jit_binary_free(struct bpf_binary_header *hdr) | |
164 | { | |
165 | module_free(NULL, hdr); | |
166 | } | |
b954d834 | 167 | #endif /* CONFIG_BPF_JIT */ |
738cbe72 | 168 | |
f5bffecd AS |
169 | /* Base function for offset calculation. Needs to go into .text section, |
170 | * therefore keeping it non-static as well; will also be used by JITs | |
171 | * anyway later on, so do not let the compiler omit it. | |
172 | */ | |
173 | noinline u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5) | |
174 | { | |
175 | return 0; | |
176 | } | |
177 | ||
178 | /** | |
7ae457c1 AS |
179 | * __bpf_prog_run - run eBPF program on a given context |
180 | * @ctx: is the data we are operating on | |
181 | * @insn: is the array of eBPF instructions | |
f5bffecd | 182 | * |
7ae457c1 | 183 | * Decode and execute eBPF instructions. |
f5bffecd | 184 | */ |
7ae457c1 | 185 | static unsigned int __bpf_prog_run(void *ctx, const struct bpf_insn *insn) |
f5bffecd AS |
186 | { |
187 | u64 stack[MAX_BPF_STACK / sizeof(u64)]; | |
188 | u64 regs[MAX_BPF_REG], tmp; | |
189 | static const void *jumptable[256] = { | |
190 | [0 ... 255] = &&default_label, | |
191 | /* Now overwrite non-defaults ... */ | |
192 | /* 32 bit ALU operations */ | |
193 | [BPF_ALU | BPF_ADD | BPF_X] = &&ALU_ADD_X, | |
194 | [BPF_ALU | BPF_ADD | BPF_K] = &&ALU_ADD_K, | |
195 | [BPF_ALU | BPF_SUB | BPF_X] = &&ALU_SUB_X, | |
196 | [BPF_ALU | BPF_SUB | BPF_K] = &&ALU_SUB_K, | |
197 | [BPF_ALU | BPF_AND | BPF_X] = &&ALU_AND_X, | |
198 | [BPF_ALU | BPF_AND | BPF_K] = &&ALU_AND_K, | |
199 | [BPF_ALU | BPF_OR | BPF_X] = &&ALU_OR_X, | |
200 | [BPF_ALU | BPF_OR | BPF_K] = &&ALU_OR_K, | |
201 | [BPF_ALU | BPF_LSH | BPF_X] = &&ALU_LSH_X, | |
202 | [BPF_ALU | BPF_LSH | BPF_K] = &&ALU_LSH_K, | |
203 | [BPF_ALU | BPF_RSH | BPF_X] = &&ALU_RSH_X, | |
204 | [BPF_ALU | BPF_RSH | BPF_K] = &&ALU_RSH_K, | |
205 | [BPF_ALU | BPF_XOR | BPF_X] = &&ALU_XOR_X, | |
206 | [BPF_ALU | BPF_XOR | BPF_K] = &&ALU_XOR_K, | |
207 | [BPF_ALU | BPF_MUL | BPF_X] = &&ALU_MUL_X, | |
208 | [BPF_ALU | BPF_MUL | BPF_K] = &&ALU_MUL_K, | |
209 | [BPF_ALU | BPF_MOV | BPF_X] = &&ALU_MOV_X, | |
210 | [BPF_ALU | BPF_MOV | BPF_K] = &&ALU_MOV_K, | |
211 | [BPF_ALU | BPF_DIV | BPF_X] = &&ALU_DIV_X, | |
212 | [BPF_ALU | BPF_DIV | BPF_K] = &&ALU_DIV_K, | |
213 | [BPF_ALU | BPF_MOD | BPF_X] = &&ALU_MOD_X, | |
214 | [BPF_ALU | BPF_MOD | BPF_K] = &&ALU_MOD_K, | |
215 | [BPF_ALU | BPF_NEG] = &&ALU_NEG, | |
216 | [BPF_ALU | BPF_END | BPF_TO_BE] = &&ALU_END_TO_BE, | |
217 | [BPF_ALU | BPF_END | BPF_TO_LE] = &&ALU_END_TO_LE, | |
218 | /* 64 bit ALU operations */ | |
219 | [BPF_ALU64 | BPF_ADD | BPF_X] = &&ALU64_ADD_X, | |
220 | [BPF_ALU64 | BPF_ADD | BPF_K] = &&ALU64_ADD_K, | |
221 | [BPF_ALU64 | BPF_SUB | BPF_X] = &&ALU64_SUB_X, | |
222 | [BPF_ALU64 | BPF_SUB | BPF_K] = &&ALU64_SUB_K, | |
223 | [BPF_ALU64 | BPF_AND | BPF_X] = &&ALU64_AND_X, | |
224 | [BPF_ALU64 | BPF_AND | BPF_K] = &&ALU64_AND_K, | |
225 | [BPF_ALU64 | BPF_OR | BPF_X] = &&ALU64_OR_X, | |
226 | [BPF_ALU64 | BPF_OR | BPF_K] = &&ALU64_OR_K, | |
227 | [BPF_ALU64 | BPF_LSH | BPF_X] = &&ALU64_LSH_X, | |
228 | [BPF_ALU64 | BPF_LSH | BPF_K] = &&ALU64_LSH_K, | |
229 | [BPF_ALU64 | BPF_RSH | BPF_X] = &&ALU64_RSH_X, | |
230 | [BPF_ALU64 | BPF_RSH | BPF_K] = &&ALU64_RSH_K, | |
231 | [BPF_ALU64 | BPF_XOR | BPF_X] = &&ALU64_XOR_X, | |
232 | [BPF_ALU64 | BPF_XOR | BPF_K] = &&ALU64_XOR_K, | |
233 | [BPF_ALU64 | BPF_MUL | BPF_X] = &&ALU64_MUL_X, | |
234 | [BPF_ALU64 | BPF_MUL | BPF_K] = &&ALU64_MUL_K, | |
235 | [BPF_ALU64 | BPF_MOV | BPF_X] = &&ALU64_MOV_X, | |
236 | [BPF_ALU64 | BPF_MOV | BPF_K] = &&ALU64_MOV_K, | |
237 | [BPF_ALU64 | BPF_ARSH | BPF_X] = &&ALU64_ARSH_X, | |
238 | [BPF_ALU64 | BPF_ARSH | BPF_K] = &&ALU64_ARSH_K, | |
239 | [BPF_ALU64 | BPF_DIV | BPF_X] = &&ALU64_DIV_X, | |
240 | [BPF_ALU64 | BPF_DIV | BPF_K] = &&ALU64_DIV_K, | |
241 | [BPF_ALU64 | BPF_MOD | BPF_X] = &&ALU64_MOD_X, | |
242 | [BPF_ALU64 | BPF_MOD | BPF_K] = &&ALU64_MOD_K, | |
243 | [BPF_ALU64 | BPF_NEG] = &&ALU64_NEG, | |
244 | /* Call instruction */ | |
245 | [BPF_JMP | BPF_CALL] = &&JMP_CALL, | |
246 | /* Jumps */ | |
247 | [BPF_JMP | BPF_JA] = &&JMP_JA, | |
248 | [BPF_JMP | BPF_JEQ | BPF_X] = &&JMP_JEQ_X, | |
249 | [BPF_JMP | BPF_JEQ | BPF_K] = &&JMP_JEQ_K, | |
250 | [BPF_JMP | BPF_JNE | BPF_X] = &&JMP_JNE_X, | |
251 | [BPF_JMP | BPF_JNE | BPF_K] = &&JMP_JNE_K, | |
252 | [BPF_JMP | BPF_JGT | BPF_X] = &&JMP_JGT_X, | |
253 | [BPF_JMP | BPF_JGT | BPF_K] = &&JMP_JGT_K, | |
254 | [BPF_JMP | BPF_JGE | BPF_X] = &&JMP_JGE_X, | |
255 | [BPF_JMP | BPF_JGE | BPF_K] = &&JMP_JGE_K, | |
256 | [BPF_JMP | BPF_JSGT | BPF_X] = &&JMP_JSGT_X, | |
257 | [BPF_JMP | BPF_JSGT | BPF_K] = &&JMP_JSGT_K, | |
258 | [BPF_JMP | BPF_JSGE | BPF_X] = &&JMP_JSGE_X, | |
259 | [BPF_JMP | BPF_JSGE | BPF_K] = &&JMP_JSGE_K, | |
260 | [BPF_JMP | BPF_JSET | BPF_X] = &&JMP_JSET_X, | |
261 | [BPF_JMP | BPF_JSET | BPF_K] = &&JMP_JSET_K, | |
262 | /* Program return */ | |
263 | [BPF_JMP | BPF_EXIT] = &&JMP_EXIT, | |
264 | /* Store instructions */ | |
265 | [BPF_STX | BPF_MEM | BPF_B] = &&STX_MEM_B, | |
266 | [BPF_STX | BPF_MEM | BPF_H] = &&STX_MEM_H, | |
267 | [BPF_STX | BPF_MEM | BPF_W] = &&STX_MEM_W, | |
268 | [BPF_STX | BPF_MEM | BPF_DW] = &&STX_MEM_DW, | |
269 | [BPF_STX | BPF_XADD | BPF_W] = &&STX_XADD_W, | |
270 | [BPF_STX | BPF_XADD | BPF_DW] = &&STX_XADD_DW, | |
271 | [BPF_ST | BPF_MEM | BPF_B] = &&ST_MEM_B, | |
272 | [BPF_ST | BPF_MEM | BPF_H] = &&ST_MEM_H, | |
273 | [BPF_ST | BPF_MEM | BPF_W] = &&ST_MEM_W, | |
274 | [BPF_ST | BPF_MEM | BPF_DW] = &&ST_MEM_DW, | |
275 | /* Load instructions */ | |
276 | [BPF_LDX | BPF_MEM | BPF_B] = &&LDX_MEM_B, | |
277 | [BPF_LDX | BPF_MEM | BPF_H] = &&LDX_MEM_H, | |
278 | [BPF_LDX | BPF_MEM | BPF_W] = &&LDX_MEM_W, | |
279 | [BPF_LDX | BPF_MEM | BPF_DW] = &&LDX_MEM_DW, | |
280 | [BPF_LD | BPF_ABS | BPF_W] = &&LD_ABS_W, | |
281 | [BPF_LD | BPF_ABS | BPF_H] = &&LD_ABS_H, | |
282 | [BPF_LD | BPF_ABS | BPF_B] = &&LD_ABS_B, | |
283 | [BPF_LD | BPF_IND | BPF_W] = &&LD_IND_W, | |
284 | [BPF_LD | BPF_IND | BPF_H] = &&LD_IND_H, | |
285 | [BPF_LD | BPF_IND | BPF_B] = &&LD_IND_B, | |
02ab695b | 286 | [BPF_LD | BPF_IMM | BPF_DW] = &&LD_IMM_DW, |
f5bffecd AS |
287 | }; |
288 | void *ptr; | |
289 | int off; | |
290 | ||
291 | #define CONT ({ insn++; goto select_insn; }) | |
292 | #define CONT_JMP ({ insn++; goto select_insn; }) | |
293 | ||
294 | FP = (u64) (unsigned long) &stack[ARRAY_SIZE(stack)]; | |
295 | ARG1 = (u64) (unsigned long) ctx; | |
296 | ||
297 | /* Registers used in classic BPF programs need to be reset first. */ | |
298 | regs[BPF_REG_A] = 0; | |
299 | regs[BPF_REG_X] = 0; | |
300 | ||
301 | select_insn: | |
302 | goto *jumptable[insn->code]; | |
303 | ||
304 | /* ALU */ | |
305 | #define ALU(OPCODE, OP) \ | |
306 | ALU64_##OPCODE##_X: \ | |
307 | DST = DST OP SRC; \ | |
308 | CONT; \ | |
309 | ALU_##OPCODE##_X: \ | |
310 | DST = (u32) DST OP (u32) SRC; \ | |
311 | CONT; \ | |
312 | ALU64_##OPCODE##_K: \ | |
313 | DST = DST OP IMM; \ | |
314 | CONT; \ | |
315 | ALU_##OPCODE##_K: \ | |
316 | DST = (u32) DST OP (u32) IMM; \ | |
317 | CONT; | |
318 | ||
319 | ALU(ADD, +) | |
320 | ALU(SUB, -) | |
321 | ALU(AND, &) | |
322 | ALU(OR, |) | |
323 | ALU(LSH, <<) | |
324 | ALU(RSH, >>) | |
325 | ALU(XOR, ^) | |
326 | ALU(MUL, *) | |
327 | #undef ALU | |
328 | ALU_NEG: | |
329 | DST = (u32) -DST; | |
330 | CONT; | |
331 | ALU64_NEG: | |
332 | DST = -DST; | |
333 | CONT; | |
334 | ALU_MOV_X: | |
335 | DST = (u32) SRC; | |
336 | CONT; | |
337 | ALU_MOV_K: | |
338 | DST = (u32) IMM; | |
339 | CONT; | |
340 | ALU64_MOV_X: | |
341 | DST = SRC; | |
342 | CONT; | |
343 | ALU64_MOV_K: | |
344 | DST = IMM; | |
345 | CONT; | |
02ab695b AS |
346 | LD_IMM_DW: |
347 | DST = (u64) (u32) insn[0].imm | ((u64) (u32) insn[1].imm) << 32; | |
348 | insn++; | |
349 | CONT; | |
f5bffecd AS |
350 | ALU64_ARSH_X: |
351 | (*(s64 *) &DST) >>= SRC; | |
352 | CONT; | |
353 | ALU64_ARSH_K: | |
354 | (*(s64 *) &DST) >>= IMM; | |
355 | CONT; | |
356 | ALU64_MOD_X: | |
357 | if (unlikely(SRC == 0)) | |
358 | return 0; | |
359 | tmp = DST; | |
360 | DST = do_div(tmp, SRC); | |
361 | CONT; | |
362 | ALU_MOD_X: | |
363 | if (unlikely(SRC == 0)) | |
364 | return 0; | |
365 | tmp = (u32) DST; | |
366 | DST = do_div(tmp, (u32) SRC); | |
367 | CONT; | |
368 | ALU64_MOD_K: | |
369 | tmp = DST; | |
370 | DST = do_div(tmp, IMM); | |
371 | CONT; | |
372 | ALU_MOD_K: | |
373 | tmp = (u32) DST; | |
374 | DST = do_div(tmp, (u32) IMM); | |
375 | CONT; | |
376 | ALU64_DIV_X: | |
377 | if (unlikely(SRC == 0)) | |
378 | return 0; | |
379 | do_div(DST, SRC); | |
380 | CONT; | |
381 | ALU_DIV_X: | |
382 | if (unlikely(SRC == 0)) | |
383 | return 0; | |
384 | tmp = (u32) DST; | |
385 | do_div(tmp, (u32) SRC); | |
386 | DST = (u32) tmp; | |
387 | CONT; | |
388 | ALU64_DIV_K: | |
389 | do_div(DST, IMM); | |
390 | CONT; | |
391 | ALU_DIV_K: | |
392 | tmp = (u32) DST; | |
393 | do_div(tmp, (u32) IMM); | |
394 | DST = (u32) tmp; | |
395 | CONT; | |
396 | ALU_END_TO_BE: | |
397 | switch (IMM) { | |
398 | case 16: | |
399 | DST = (__force u16) cpu_to_be16(DST); | |
400 | break; | |
401 | case 32: | |
402 | DST = (__force u32) cpu_to_be32(DST); | |
403 | break; | |
404 | case 64: | |
405 | DST = (__force u64) cpu_to_be64(DST); | |
406 | break; | |
407 | } | |
408 | CONT; | |
409 | ALU_END_TO_LE: | |
410 | switch (IMM) { | |
411 | case 16: | |
412 | DST = (__force u16) cpu_to_le16(DST); | |
413 | break; | |
414 | case 32: | |
415 | DST = (__force u32) cpu_to_le32(DST); | |
416 | break; | |
417 | case 64: | |
418 | DST = (__force u64) cpu_to_le64(DST); | |
419 | break; | |
420 | } | |
421 | CONT; | |
422 | ||
423 | /* CALL */ | |
424 | JMP_CALL: | |
425 | /* Function call scratches BPF_R1-BPF_R5 registers, | |
426 | * preserves BPF_R6-BPF_R9, and stores return value | |
427 | * into BPF_R0. | |
428 | */ | |
429 | BPF_R0 = (__bpf_call_base + insn->imm)(BPF_R1, BPF_R2, BPF_R3, | |
430 | BPF_R4, BPF_R5); | |
431 | CONT; | |
432 | ||
433 | /* JMP */ | |
434 | JMP_JA: | |
435 | insn += insn->off; | |
436 | CONT; | |
437 | JMP_JEQ_X: | |
438 | if (DST == SRC) { | |
439 | insn += insn->off; | |
440 | CONT_JMP; | |
441 | } | |
442 | CONT; | |
443 | JMP_JEQ_K: | |
444 | if (DST == IMM) { | |
445 | insn += insn->off; | |
446 | CONT_JMP; | |
447 | } | |
448 | CONT; | |
449 | JMP_JNE_X: | |
450 | if (DST != SRC) { | |
451 | insn += insn->off; | |
452 | CONT_JMP; | |
453 | } | |
454 | CONT; | |
455 | JMP_JNE_K: | |
456 | if (DST != IMM) { | |
457 | insn += insn->off; | |
458 | CONT_JMP; | |
459 | } | |
460 | CONT; | |
461 | JMP_JGT_X: | |
462 | if (DST > SRC) { | |
463 | insn += insn->off; | |
464 | CONT_JMP; | |
465 | } | |
466 | CONT; | |
467 | JMP_JGT_K: | |
468 | if (DST > IMM) { | |
469 | insn += insn->off; | |
470 | CONT_JMP; | |
471 | } | |
472 | CONT; | |
473 | JMP_JGE_X: | |
474 | if (DST >= SRC) { | |
475 | insn += insn->off; | |
476 | CONT_JMP; | |
477 | } | |
478 | CONT; | |
479 | JMP_JGE_K: | |
480 | if (DST >= IMM) { | |
481 | insn += insn->off; | |
482 | CONT_JMP; | |
483 | } | |
484 | CONT; | |
485 | JMP_JSGT_X: | |
486 | if (((s64) DST) > ((s64) SRC)) { | |
487 | insn += insn->off; | |
488 | CONT_JMP; | |
489 | } | |
490 | CONT; | |
491 | JMP_JSGT_K: | |
492 | if (((s64) DST) > ((s64) IMM)) { | |
493 | insn += insn->off; | |
494 | CONT_JMP; | |
495 | } | |
496 | CONT; | |
497 | JMP_JSGE_X: | |
498 | if (((s64) DST) >= ((s64) SRC)) { | |
499 | insn += insn->off; | |
500 | CONT_JMP; | |
501 | } | |
502 | CONT; | |
503 | JMP_JSGE_K: | |
504 | if (((s64) DST) >= ((s64) IMM)) { | |
505 | insn += insn->off; | |
506 | CONT_JMP; | |
507 | } | |
508 | CONT; | |
509 | JMP_JSET_X: | |
510 | if (DST & SRC) { | |
511 | insn += insn->off; | |
512 | CONT_JMP; | |
513 | } | |
514 | CONT; | |
515 | JMP_JSET_K: | |
516 | if (DST & IMM) { | |
517 | insn += insn->off; | |
518 | CONT_JMP; | |
519 | } | |
520 | CONT; | |
521 | JMP_EXIT: | |
522 | return BPF_R0; | |
523 | ||
524 | /* STX and ST and LDX*/ | |
525 | #define LDST(SIZEOP, SIZE) \ | |
526 | STX_MEM_##SIZEOP: \ | |
527 | *(SIZE *)(unsigned long) (DST + insn->off) = SRC; \ | |
528 | CONT; \ | |
529 | ST_MEM_##SIZEOP: \ | |
530 | *(SIZE *)(unsigned long) (DST + insn->off) = IMM; \ | |
531 | CONT; \ | |
532 | LDX_MEM_##SIZEOP: \ | |
533 | DST = *(SIZE *)(unsigned long) (SRC + insn->off); \ | |
534 | CONT; | |
535 | ||
536 | LDST(B, u8) | |
537 | LDST(H, u16) | |
538 | LDST(W, u32) | |
539 | LDST(DW, u64) | |
540 | #undef LDST | |
541 | STX_XADD_W: /* lock xadd *(u32 *)(dst_reg + off16) += src_reg */ | |
542 | atomic_add((u32) SRC, (atomic_t *)(unsigned long) | |
543 | (DST + insn->off)); | |
544 | CONT; | |
545 | STX_XADD_DW: /* lock xadd *(u64 *)(dst_reg + off16) += src_reg */ | |
546 | atomic64_add((u64) SRC, (atomic64_t *)(unsigned long) | |
547 | (DST + insn->off)); | |
548 | CONT; | |
549 | LD_ABS_W: /* BPF_R0 = ntohl(*(u32 *) (skb->data + imm32)) */ | |
550 | off = IMM; | |
551 | load_word: | |
552 | /* BPF_LD + BPD_ABS and BPF_LD + BPF_IND insns are | |
553 | * only appearing in the programs where ctx == | |
554 | * skb. All programs keep 'ctx' in regs[BPF_REG_CTX] | |
8fb575ca | 555 | * == BPF_R6, bpf_convert_filter() saves it in BPF_R6, |
f5bffecd AS |
556 | * internal BPF verifier will check that BPF_R6 == |
557 | * ctx. | |
558 | * | |
559 | * BPF_ABS and BPF_IND are wrappers of function calls, | |
560 | * so they scratch BPF_R1-BPF_R5 registers, preserve | |
561 | * BPF_R6-BPF_R9, and store return value into BPF_R0. | |
562 | * | |
563 | * Implicit input: | |
564 | * ctx == skb == BPF_R6 == CTX | |
565 | * | |
566 | * Explicit input: | |
567 | * SRC == any register | |
568 | * IMM == 32-bit immediate | |
569 | * | |
570 | * Output: | |
571 | * BPF_R0 - 8/16/32-bit skb data converted to cpu endianness | |
572 | */ | |
573 | ||
574 | ptr = bpf_load_pointer((struct sk_buff *) (unsigned long) CTX, off, 4, &tmp); | |
575 | if (likely(ptr != NULL)) { | |
576 | BPF_R0 = get_unaligned_be32(ptr); | |
577 | CONT; | |
578 | } | |
579 | ||
580 | return 0; | |
581 | LD_ABS_H: /* BPF_R0 = ntohs(*(u16 *) (skb->data + imm32)) */ | |
582 | off = IMM; | |
583 | load_half: | |
584 | ptr = bpf_load_pointer((struct sk_buff *) (unsigned long) CTX, off, 2, &tmp); | |
585 | if (likely(ptr != NULL)) { | |
586 | BPF_R0 = get_unaligned_be16(ptr); | |
587 | CONT; | |
588 | } | |
589 | ||
590 | return 0; | |
591 | LD_ABS_B: /* BPF_R0 = *(u8 *) (skb->data + imm32) */ | |
592 | off = IMM; | |
593 | load_byte: | |
594 | ptr = bpf_load_pointer((struct sk_buff *) (unsigned long) CTX, off, 1, &tmp); | |
595 | if (likely(ptr != NULL)) { | |
596 | BPF_R0 = *(u8 *)ptr; | |
597 | CONT; | |
598 | } | |
599 | ||
600 | return 0; | |
601 | LD_IND_W: /* BPF_R0 = ntohl(*(u32 *) (skb->data + src_reg + imm32)) */ | |
602 | off = IMM + SRC; | |
603 | goto load_word; | |
604 | LD_IND_H: /* BPF_R0 = ntohs(*(u16 *) (skb->data + src_reg + imm32)) */ | |
605 | off = IMM + SRC; | |
606 | goto load_half; | |
607 | LD_IND_B: /* BPF_R0 = *(u8 *) (skb->data + src_reg + imm32) */ | |
608 | off = IMM + SRC; | |
609 | goto load_byte; | |
610 | ||
611 | default_label: | |
612 | /* If we ever reach this, we have a bug somewhere. */ | |
613 | WARN_RATELIMIT(1, "unknown opcode %02x\n", insn->code); | |
614 | return 0; | |
615 | } | |
616 | ||
7ae457c1 | 617 | void __weak bpf_int_jit_compile(struct bpf_prog *prog) |
f5bffecd AS |
618 | { |
619 | } | |
620 | ||
621 | /** | |
7ae457c1 AS |
622 | * bpf_prog_select_runtime - select execution runtime for BPF program |
623 | * @fp: bpf_prog populated with internal BPF program | |
f5bffecd AS |
624 | * |
625 | * try to JIT internal BPF program, if JIT is not available select interpreter | |
7ae457c1 | 626 | * BPF program will be executed via BPF_PROG_RUN() macro |
f5bffecd | 627 | */ |
7ae457c1 | 628 | void bpf_prog_select_runtime(struct bpf_prog *fp) |
f5bffecd | 629 | { |
7ae457c1 | 630 | fp->bpf_func = (void *) __bpf_prog_run; |
f5bffecd AS |
631 | |
632 | /* Probe if internal BPF can be JITed */ | |
633 | bpf_int_jit_compile(fp); | |
60a3b225 DB |
634 | /* Lock whole bpf_prog as read-only */ |
635 | bpf_prog_lock_ro(fp); | |
f5bffecd | 636 | } |
7ae457c1 | 637 | EXPORT_SYMBOL_GPL(bpf_prog_select_runtime); |
f5bffecd | 638 | |
60a3b225 DB |
639 | static void bpf_prog_free_deferred(struct work_struct *work) |
640 | { | |
641 | struct bpf_work_struct *ws; | |
642 | ||
643 | ws = container_of(work, struct bpf_work_struct, work); | |
644 | bpf_jit_free(ws->prog); | |
645 | } | |
646 | ||
647 | /* Free internal BPF program */ | |
7ae457c1 | 648 | void bpf_prog_free(struct bpf_prog *fp) |
f5bffecd | 649 | { |
60a3b225 DB |
650 | struct bpf_work_struct *ws = fp->work; |
651 | ||
652 | INIT_WORK(&ws->work, bpf_prog_free_deferred); | |
653 | ws->prog = fp; | |
654 | schedule_work(&ws->work); | |
f5bffecd | 655 | } |
7ae457c1 | 656 | EXPORT_SYMBOL_GPL(bpf_prog_free); |