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0a14842f ED |
1 | /* bpf_jit_comp.c : BPF JIT compiler |
2 | * | |
3b58908a | 3 | * Copyright (C) 2011-2013 Eric Dumazet (eric.dumazet@gmail.com) |
62258278 | 4 | * Internal BPF Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com |
0a14842f ED |
5 | * |
6 | * This program is free software; you can redistribute it and/or | |
7 | * modify it under the terms of the GNU General Public License | |
8 | * as published by the Free Software Foundation; version 2 | |
9 | * of the License. | |
10 | */ | |
0a14842f ED |
11 | #include <linux/netdevice.h> |
12 | #include <linux/filter.h> | |
855ddb56 | 13 | #include <linux/if_vlan.h> |
738cbe72 | 14 | #include <asm/cacheflush.h> |
b52f00e6 | 15 | #include <linux/bpf.h> |
0a14842f | 16 | |
0a14842f ED |
17 | int bpf_jit_enable __read_mostly; |
18 | ||
19 | /* | |
20 | * assembly code in arch/x86/net/bpf_jit.S | |
21 | */ | |
62258278 | 22 | extern u8 sk_load_word[], sk_load_half[], sk_load_byte[]; |
a998d434 | 23 | extern u8 sk_load_word_positive_offset[], sk_load_half_positive_offset[]; |
62258278 | 24 | extern u8 sk_load_byte_positive_offset[]; |
a998d434 | 25 | extern u8 sk_load_word_negative_offset[], sk_load_half_negative_offset[]; |
62258278 | 26 | extern u8 sk_load_byte_negative_offset[]; |
0a14842f | 27 | |
5cccc702 | 28 | static u8 *emit_code(u8 *ptr, u32 bytes, unsigned int len) |
0a14842f ED |
29 | { |
30 | if (len == 1) | |
31 | *ptr = bytes; | |
32 | else if (len == 2) | |
33 | *(u16 *)ptr = bytes; | |
34 | else { | |
35 | *(u32 *)ptr = bytes; | |
36 | barrier(); | |
37 | } | |
38 | return ptr + len; | |
39 | } | |
40 | ||
b52f00e6 AS |
41 | #define EMIT(bytes, len) \ |
42 | do { prog = emit_code(prog, bytes, len); cnt += len; } while (0) | |
0a14842f ED |
43 | |
44 | #define EMIT1(b1) EMIT(b1, 1) | |
45 | #define EMIT2(b1, b2) EMIT((b1) + ((b2) << 8), 2) | |
46 | #define EMIT3(b1, b2, b3) EMIT((b1) + ((b2) << 8) + ((b3) << 16), 3) | |
47 | #define EMIT4(b1, b2, b3, b4) EMIT((b1) + ((b2) << 8) + ((b3) << 16) + ((b4) << 24), 4) | |
62258278 AS |
48 | #define EMIT1_off32(b1, off) \ |
49 | do {EMIT1(b1); EMIT(off, 4); } while (0) | |
50 | #define EMIT2_off32(b1, b2, off) \ | |
51 | do {EMIT2(b1, b2); EMIT(off, 4); } while (0) | |
52 | #define EMIT3_off32(b1, b2, b3, off) \ | |
53 | do {EMIT3(b1, b2, b3); EMIT(off, 4); } while (0) | |
54 | #define EMIT4_off32(b1, b2, b3, b4, off) \ | |
55 | do {EMIT4(b1, b2, b3, b4); EMIT(off, 4); } while (0) | |
0a14842f | 56 | |
5cccc702 | 57 | static bool is_imm8(int value) |
0a14842f ED |
58 | { |
59 | return value <= 127 && value >= -128; | |
60 | } | |
61 | ||
5cccc702 | 62 | static bool is_simm32(s64 value) |
0a14842f | 63 | { |
62258278 | 64 | return value == (s64) (s32) value; |
0a14842f ED |
65 | } |
66 | ||
e430f34e AS |
67 | /* mov dst, src */ |
68 | #define EMIT_mov(DST, SRC) \ | |
69 | do {if (DST != SRC) \ | |
70 | EMIT3(add_2mod(0x48, DST, SRC), 0x89, add_2reg(0xC0, DST, SRC)); \ | |
62258278 AS |
71 | } while (0) |
72 | ||
73 | static int bpf_size_to_x86_bytes(int bpf_size) | |
74 | { | |
75 | if (bpf_size == BPF_W) | |
76 | return 4; | |
77 | else if (bpf_size == BPF_H) | |
78 | return 2; | |
79 | else if (bpf_size == BPF_B) | |
80 | return 1; | |
81 | else if (bpf_size == BPF_DW) | |
82 | return 4; /* imm32 */ | |
83 | else | |
84 | return 0; | |
85 | } | |
0a14842f ED |
86 | |
87 | /* list of x86 cond jumps opcodes (. + s8) | |
88 | * Add 0x10 (and an extra 0x0f) to generate far jumps (. + s32) | |
89 | */ | |
90 | #define X86_JB 0x72 | |
91 | #define X86_JAE 0x73 | |
92 | #define X86_JE 0x74 | |
93 | #define X86_JNE 0x75 | |
94 | #define X86_JBE 0x76 | |
95 | #define X86_JA 0x77 | |
62258278 AS |
96 | #define X86_JGE 0x7D |
97 | #define X86_JG 0x7F | |
0a14842f | 98 | |
5cccc702 | 99 | static void bpf_flush_icache(void *start, void *end) |
0a14842f ED |
100 | { |
101 | mm_segment_t old_fs = get_fs(); | |
102 | ||
103 | set_fs(KERNEL_DS); | |
104 | smp_wmb(); | |
105 | flush_icache_range((unsigned long)start, (unsigned long)end); | |
106 | set_fs(old_fs); | |
107 | } | |
108 | ||
a998d434 JS |
109 | #define CHOOSE_LOAD_FUNC(K, func) \ |
110 | ((int)K < 0 ? ((int)K >= SKF_LL_OFF ? func##_negative_offset : func) : func##_positive_offset) | |
0a14842f | 111 | |
62258278 AS |
112 | /* pick a register outside of BPF range for JIT internal work */ |
113 | #define AUX_REG (MAX_BPF_REG + 1) | |
114 | ||
115 | /* the following table maps BPF registers to x64 registers. | |
116 | * x64 register r12 is unused, since if used as base address register | |
117 | * in load/store instructions, it always needs an extra byte of encoding | |
118 | */ | |
119 | static const int reg2hex[] = { | |
120 | [BPF_REG_0] = 0, /* rax */ | |
121 | [BPF_REG_1] = 7, /* rdi */ | |
122 | [BPF_REG_2] = 6, /* rsi */ | |
123 | [BPF_REG_3] = 2, /* rdx */ | |
124 | [BPF_REG_4] = 1, /* rcx */ | |
125 | [BPF_REG_5] = 0, /* r8 */ | |
126 | [BPF_REG_6] = 3, /* rbx callee saved */ | |
127 | [BPF_REG_7] = 5, /* r13 callee saved */ | |
128 | [BPF_REG_8] = 6, /* r14 callee saved */ | |
129 | [BPF_REG_9] = 7, /* r15 callee saved */ | |
130 | [BPF_REG_FP] = 5, /* rbp readonly */ | |
131 | [AUX_REG] = 3, /* r11 temp register */ | |
132 | }; | |
133 | ||
134 | /* is_ereg() == true if BPF register 'reg' maps to x64 r8..r15 | |
135 | * which need extra byte of encoding. | |
136 | * rax,rcx,...,rbp have simpler encoding | |
137 | */ | |
5cccc702 | 138 | static bool is_ereg(u32 reg) |
62258278 | 139 | { |
d148134b JP |
140 | return (1 << reg) & (BIT(BPF_REG_5) | |
141 | BIT(AUX_REG) | | |
142 | BIT(BPF_REG_7) | | |
143 | BIT(BPF_REG_8) | | |
144 | BIT(BPF_REG_9)); | |
62258278 AS |
145 | } |
146 | ||
147 | /* add modifiers if 'reg' maps to x64 registers r8..r15 */ | |
5cccc702 | 148 | static u8 add_1mod(u8 byte, u32 reg) |
62258278 AS |
149 | { |
150 | if (is_ereg(reg)) | |
151 | byte |= 1; | |
152 | return byte; | |
153 | } | |
154 | ||
5cccc702 | 155 | static u8 add_2mod(u8 byte, u32 r1, u32 r2) |
62258278 AS |
156 | { |
157 | if (is_ereg(r1)) | |
158 | byte |= 1; | |
159 | if (is_ereg(r2)) | |
160 | byte |= 4; | |
161 | return byte; | |
162 | } | |
163 | ||
e430f34e | 164 | /* encode 'dst_reg' register into x64 opcode 'byte' */ |
5cccc702 | 165 | static u8 add_1reg(u8 byte, u32 dst_reg) |
62258278 | 166 | { |
e430f34e | 167 | return byte + reg2hex[dst_reg]; |
62258278 AS |
168 | } |
169 | ||
e430f34e | 170 | /* encode 'dst_reg' and 'src_reg' registers into x64 opcode 'byte' */ |
5cccc702 | 171 | static u8 add_2reg(u8 byte, u32 dst_reg, u32 src_reg) |
62258278 | 172 | { |
e430f34e | 173 | return byte + reg2hex[dst_reg] + (reg2hex[src_reg] << 3); |
62258278 AS |
174 | } |
175 | ||
738cbe72 DB |
176 | static void jit_fill_hole(void *area, unsigned int size) |
177 | { | |
178 | /* fill whole space with int3 instructions */ | |
179 | memset(area, 0xcc, size); | |
180 | } | |
181 | ||
f3c2af7b | 182 | struct jit_context { |
769e0de6 | 183 | int cleanup_addr; /* epilogue code offset */ |
62258278 | 184 | bool seen_ld_abs; |
f3c2af7b AS |
185 | }; |
186 | ||
e0ee9c12 AS |
187 | /* maximum number of bytes emitted while JITing one eBPF insn */ |
188 | #define BPF_MAX_INSN_SIZE 128 | |
189 | #define BPF_INSN_SAFETY 64 | |
190 | ||
b52f00e6 AS |
191 | #define STACKSIZE \ |
192 | (MAX_BPF_STACK + \ | |
193 | 32 /* space for rbx, r13, r14, r15 */ + \ | |
194 | 8 /* space for skb_copy_bits() buffer */) | |
195 | ||
8b614aeb | 196 | #define PROLOGUE_SIZE 48 |
b52f00e6 AS |
197 | |
198 | /* emit x64 prologue code for BPF program and check it's size. | |
199 | * bpf_tail_call helper will skip it while jumping into another program | |
200 | */ | |
201 | static void emit_prologue(u8 **pprog) | |
0a14842f | 202 | { |
b52f00e6 AS |
203 | u8 *prog = *pprog; |
204 | int cnt = 0; | |
0a14842f | 205 | |
62258278 AS |
206 | EMIT1(0x55); /* push rbp */ |
207 | EMIT3(0x48, 0x89, 0xE5); /* mov rbp,rsp */ | |
0a14842f | 208 | |
b52f00e6 AS |
209 | /* sub rsp, STACKSIZE */ |
210 | EMIT3_off32(0x48, 0x81, 0xEC, STACKSIZE); | |
62258278 AS |
211 | |
212 | /* all classic BPF filters use R6(rbx) save it */ | |
213 | ||
214 | /* mov qword ptr [rbp-X],rbx */ | |
b52f00e6 | 215 | EMIT3_off32(0x48, 0x89, 0x9D, -STACKSIZE); |
62258278 | 216 | |
8fb575ca | 217 | /* bpf_convert_filter() maps classic BPF register X to R7 and uses R8 |
62258278 AS |
218 | * as temporary, so all tcpdump filters need to spill/fill R7(r13) and |
219 | * R8(r14). R9(r15) spill could be made conditional, but there is only | |
220 | * one 'bpf_error' return path out of helper functions inside bpf_jit.S | |
221 | * The overhead of extra spill is negligible for any filter other | |
222 | * than synthetic ones. Therefore not worth adding complexity. | |
223 | */ | |
224 | ||
225 | /* mov qword ptr [rbp-X],r13 */ | |
b52f00e6 | 226 | EMIT3_off32(0x4C, 0x89, 0xAD, -STACKSIZE + 8); |
62258278 | 227 | /* mov qword ptr [rbp-X],r14 */ |
b52f00e6 | 228 | EMIT3_off32(0x4C, 0x89, 0xB5, -STACKSIZE + 16); |
62258278 | 229 | /* mov qword ptr [rbp-X],r15 */ |
b52f00e6 | 230 | EMIT3_off32(0x4C, 0x89, 0xBD, -STACKSIZE + 24); |
62258278 | 231 | |
8b614aeb DB |
232 | /* Clear the tail call counter (tail_call_cnt): for eBPF tail calls |
233 | * we need to reset the counter to 0. It's done in two instructions, | |
234 | * resetting rax register to 0 (xor on eax gets 0 extended), and | |
235 | * moving it to the counter location. | |
236 | */ | |
62258278 | 237 | |
8b614aeb DB |
238 | /* xor eax, eax */ |
239 | EMIT2(0x31, 0xc0); | |
240 | /* mov qword ptr [rbp-X], rax */ | |
b52f00e6 AS |
241 | EMIT3_off32(0x48, 0x89, 0x85, -STACKSIZE + 32); |
242 | ||
243 | BUILD_BUG_ON(cnt != PROLOGUE_SIZE); | |
244 | *pprog = prog; | |
245 | } | |
246 | ||
247 | /* generate the following code: | |
248 | * ... bpf_tail_call(void *ctx, struct bpf_array *array, u64 index) ... | |
249 | * if (index >= array->map.max_entries) | |
250 | * goto out; | |
251 | * if (++tail_call_cnt > MAX_TAIL_CALL_CNT) | |
252 | * goto out; | |
2a36f0b9 | 253 | * prog = array->ptrs[index]; |
b52f00e6 AS |
254 | * if (prog == NULL) |
255 | * goto out; | |
256 | * goto *(prog->bpf_func + prologue_size); | |
257 | * out: | |
258 | */ | |
259 | static void emit_bpf_tail_call(u8 **pprog) | |
260 | { | |
261 | u8 *prog = *pprog; | |
262 | int label1, label2, label3; | |
263 | int cnt = 0; | |
264 | ||
265 | /* rdi - pointer to ctx | |
266 | * rsi - pointer to bpf_array | |
267 | * rdx - index in bpf_array | |
268 | */ | |
269 | ||
270 | /* if (index >= array->map.max_entries) | |
271 | * goto out; | |
272 | */ | |
273 | EMIT4(0x48, 0x8B, 0x46, /* mov rax, qword ptr [rsi + 16] */ | |
274 | offsetof(struct bpf_array, map.max_entries)); | |
275 | EMIT3(0x48, 0x39, 0xD0); /* cmp rax, rdx */ | |
2482abb9 | 276 | #define OFFSET1 47 /* number of bytes to jump */ |
b52f00e6 AS |
277 | EMIT2(X86_JBE, OFFSET1); /* jbe out */ |
278 | label1 = cnt; | |
279 | ||
280 | /* if (tail_call_cnt > MAX_TAIL_CALL_CNT) | |
281 | * goto out; | |
282 | */ | |
283 | EMIT2_off32(0x8B, 0x85, -STACKSIZE + 36); /* mov eax, dword ptr [rbp - 516] */ | |
284 | EMIT3(0x83, 0xF8, MAX_TAIL_CALL_CNT); /* cmp eax, MAX_TAIL_CALL_CNT */ | |
2482abb9 | 285 | #define OFFSET2 36 |
b52f00e6 AS |
286 | EMIT2(X86_JA, OFFSET2); /* ja out */ |
287 | label2 = cnt; | |
288 | EMIT3(0x83, 0xC0, 0x01); /* add eax, 1 */ | |
289 | EMIT2_off32(0x89, 0x85, -STACKSIZE + 36); /* mov dword ptr [rbp - 516], eax */ | |
290 | ||
2a36f0b9 | 291 | /* prog = array->ptrs[index]; */ |
2482abb9 | 292 | EMIT4_off32(0x48, 0x8D, 0x84, 0xD6, /* lea rax, [rsi + rdx * 8 + offsetof(...)] */ |
2a36f0b9 | 293 | offsetof(struct bpf_array, ptrs)); |
b52f00e6 AS |
294 | EMIT3(0x48, 0x8B, 0x00); /* mov rax, qword ptr [rax] */ |
295 | ||
296 | /* if (prog == NULL) | |
297 | * goto out; | |
298 | */ | |
299 | EMIT4(0x48, 0x83, 0xF8, 0x00); /* cmp rax, 0 */ | |
300 | #define OFFSET3 10 | |
301 | EMIT2(X86_JE, OFFSET3); /* je out */ | |
302 | label3 = cnt; | |
303 | ||
304 | /* goto *(prog->bpf_func + prologue_size); */ | |
305 | EMIT4(0x48, 0x8B, 0x40, /* mov rax, qword ptr [rax + 32] */ | |
306 | offsetof(struct bpf_prog, bpf_func)); | |
307 | EMIT4(0x48, 0x83, 0xC0, PROLOGUE_SIZE); /* add rax, prologue_size */ | |
308 | ||
309 | /* now we're ready to jump into next BPF program | |
310 | * rdi == ctx (1st arg) | |
311 | * rax == prog->bpf_func + prologue_size | |
312 | */ | |
313 | EMIT2(0xFF, 0xE0); /* jmp rax */ | |
314 | ||
315 | /* out: */ | |
316 | BUILD_BUG_ON(cnt - label1 != OFFSET1); | |
317 | BUILD_BUG_ON(cnt - label2 != OFFSET2); | |
318 | BUILD_BUG_ON(cnt - label3 != OFFSET3); | |
319 | *pprog = prog; | |
320 | } | |
321 | ||
4e10df9a AS |
322 | |
323 | static void emit_load_skb_data_hlen(u8 **pprog) | |
324 | { | |
325 | u8 *prog = *pprog; | |
326 | int cnt = 0; | |
327 | ||
328 | /* r9d = skb->len - skb->data_len (headlen) | |
329 | * r10 = skb->data | |
330 | */ | |
331 | /* mov %r9d, off32(%rdi) */ | |
332 | EMIT3_off32(0x44, 0x8b, 0x8f, offsetof(struct sk_buff, len)); | |
333 | ||
334 | /* sub %r9d, off32(%rdi) */ | |
335 | EMIT3_off32(0x44, 0x2b, 0x8f, offsetof(struct sk_buff, data_len)); | |
336 | ||
337 | /* mov %r10, off32(%rdi) */ | |
338 | EMIT3_off32(0x4c, 0x8b, 0x97, offsetof(struct sk_buff, data)); | |
339 | *pprog = prog; | |
340 | } | |
341 | ||
b52f00e6 AS |
342 | static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image, |
343 | int oldproglen, struct jit_context *ctx) | |
344 | { | |
345 | struct bpf_insn *insn = bpf_prog->insnsi; | |
346 | int insn_cnt = bpf_prog->len; | |
347 | bool seen_ld_abs = ctx->seen_ld_abs | (oldproglen == 0); | |
348 | bool seen_exit = false; | |
349 | u8 temp[BPF_MAX_INSN_SIZE + BPF_INSN_SAFETY]; | |
350 | int i, cnt = 0; | |
351 | int proglen = 0; | |
352 | u8 *prog = temp; | |
353 | ||
354 | emit_prologue(&prog); | |
355 | ||
4e10df9a AS |
356 | if (seen_ld_abs) |
357 | emit_load_skb_data_hlen(&prog); | |
62258278 AS |
358 | |
359 | for (i = 0; i < insn_cnt; i++, insn++) { | |
e430f34e AS |
360 | const s32 imm32 = insn->imm; |
361 | u32 dst_reg = insn->dst_reg; | |
362 | u32 src_reg = insn->src_reg; | |
62258278 AS |
363 | u8 b1 = 0, b2 = 0, b3 = 0; |
364 | s64 jmp_offset; | |
365 | u8 jmp_cond; | |
4e10df9a | 366 | bool reload_skb_data; |
62258278 AS |
367 | int ilen; |
368 | u8 *func; | |
369 | ||
370 | switch (insn->code) { | |
371 | /* ALU */ | |
372 | case BPF_ALU | BPF_ADD | BPF_X: | |
373 | case BPF_ALU | BPF_SUB | BPF_X: | |
374 | case BPF_ALU | BPF_AND | BPF_X: | |
375 | case BPF_ALU | BPF_OR | BPF_X: | |
376 | case BPF_ALU | BPF_XOR | BPF_X: | |
377 | case BPF_ALU64 | BPF_ADD | BPF_X: | |
378 | case BPF_ALU64 | BPF_SUB | BPF_X: | |
379 | case BPF_ALU64 | BPF_AND | BPF_X: | |
380 | case BPF_ALU64 | BPF_OR | BPF_X: | |
381 | case BPF_ALU64 | BPF_XOR | BPF_X: | |
382 | switch (BPF_OP(insn->code)) { | |
383 | case BPF_ADD: b2 = 0x01; break; | |
384 | case BPF_SUB: b2 = 0x29; break; | |
385 | case BPF_AND: b2 = 0x21; break; | |
386 | case BPF_OR: b2 = 0x09; break; | |
387 | case BPF_XOR: b2 = 0x31; break; | |
0a14842f | 388 | } |
62258278 | 389 | if (BPF_CLASS(insn->code) == BPF_ALU64) |
e430f34e AS |
390 | EMIT1(add_2mod(0x48, dst_reg, src_reg)); |
391 | else if (is_ereg(dst_reg) || is_ereg(src_reg)) | |
392 | EMIT1(add_2mod(0x40, dst_reg, src_reg)); | |
393 | EMIT2(b2, add_2reg(0xC0, dst_reg, src_reg)); | |
62258278 | 394 | break; |
0a14842f | 395 | |
e430f34e | 396 | /* mov dst, src */ |
62258278 | 397 | case BPF_ALU64 | BPF_MOV | BPF_X: |
e430f34e | 398 | EMIT_mov(dst_reg, src_reg); |
0a14842f | 399 | break; |
0a14842f | 400 | |
e430f34e | 401 | /* mov32 dst, src */ |
62258278 | 402 | case BPF_ALU | BPF_MOV | BPF_X: |
e430f34e AS |
403 | if (is_ereg(dst_reg) || is_ereg(src_reg)) |
404 | EMIT1(add_2mod(0x40, dst_reg, src_reg)); | |
405 | EMIT2(0x89, add_2reg(0xC0, dst_reg, src_reg)); | |
62258278 | 406 | break; |
0a14842f | 407 | |
e430f34e | 408 | /* neg dst */ |
62258278 AS |
409 | case BPF_ALU | BPF_NEG: |
410 | case BPF_ALU64 | BPF_NEG: | |
411 | if (BPF_CLASS(insn->code) == BPF_ALU64) | |
e430f34e AS |
412 | EMIT1(add_1mod(0x48, dst_reg)); |
413 | else if (is_ereg(dst_reg)) | |
414 | EMIT1(add_1mod(0x40, dst_reg)); | |
415 | EMIT2(0xF7, add_1reg(0xD8, dst_reg)); | |
62258278 AS |
416 | break; |
417 | ||
418 | case BPF_ALU | BPF_ADD | BPF_K: | |
419 | case BPF_ALU | BPF_SUB | BPF_K: | |
420 | case BPF_ALU | BPF_AND | BPF_K: | |
421 | case BPF_ALU | BPF_OR | BPF_K: | |
422 | case BPF_ALU | BPF_XOR | BPF_K: | |
423 | case BPF_ALU64 | BPF_ADD | BPF_K: | |
424 | case BPF_ALU64 | BPF_SUB | BPF_K: | |
425 | case BPF_ALU64 | BPF_AND | BPF_K: | |
426 | case BPF_ALU64 | BPF_OR | BPF_K: | |
427 | case BPF_ALU64 | BPF_XOR | BPF_K: | |
428 | if (BPF_CLASS(insn->code) == BPF_ALU64) | |
e430f34e AS |
429 | EMIT1(add_1mod(0x48, dst_reg)); |
430 | else if (is_ereg(dst_reg)) | |
431 | EMIT1(add_1mod(0x40, dst_reg)); | |
62258278 AS |
432 | |
433 | switch (BPF_OP(insn->code)) { | |
434 | case BPF_ADD: b3 = 0xC0; break; | |
435 | case BPF_SUB: b3 = 0xE8; break; | |
436 | case BPF_AND: b3 = 0xE0; break; | |
437 | case BPF_OR: b3 = 0xC8; break; | |
438 | case BPF_XOR: b3 = 0xF0; break; | |
439 | } | |
440 | ||
e430f34e AS |
441 | if (is_imm8(imm32)) |
442 | EMIT3(0x83, add_1reg(b3, dst_reg), imm32); | |
62258278 | 443 | else |
e430f34e | 444 | EMIT2_off32(0x81, add_1reg(b3, dst_reg), imm32); |
62258278 AS |
445 | break; |
446 | ||
447 | case BPF_ALU64 | BPF_MOV | BPF_K: | |
448 | /* optimization: if imm32 is positive, | |
449 | * use 'mov eax, imm32' (which zero-extends imm32) | |
450 | * to save 2 bytes | |
451 | */ | |
e430f34e | 452 | if (imm32 < 0) { |
62258278 | 453 | /* 'mov rax, imm32' sign extends imm32 */ |
e430f34e | 454 | b1 = add_1mod(0x48, dst_reg); |
62258278 AS |
455 | b2 = 0xC7; |
456 | b3 = 0xC0; | |
e430f34e | 457 | EMIT3_off32(b1, b2, add_1reg(b3, dst_reg), imm32); |
0a14842f | 458 | break; |
62258278 AS |
459 | } |
460 | ||
461 | case BPF_ALU | BPF_MOV | BPF_K: | |
606c88a8 DB |
462 | /* optimization: if imm32 is zero, use 'xor <dst>,<dst>' |
463 | * to save 3 bytes. | |
464 | */ | |
465 | if (imm32 == 0) { | |
466 | if (is_ereg(dst_reg)) | |
467 | EMIT1(add_2mod(0x40, dst_reg, dst_reg)); | |
468 | b2 = 0x31; /* xor */ | |
469 | b3 = 0xC0; | |
470 | EMIT2(b2, add_2reg(b3, dst_reg, dst_reg)); | |
471 | break; | |
472 | } | |
473 | ||
62258278 | 474 | /* mov %eax, imm32 */ |
e430f34e AS |
475 | if (is_ereg(dst_reg)) |
476 | EMIT1(add_1mod(0x40, dst_reg)); | |
477 | EMIT1_off32(add_1reg(0xB8, dst_reg), imm32); | |
62258278 AS |
478 | break; |
479 | ||
02ab695b AS |
480 | case BPF_LD | BPF_IMM | BPF_DW: |
481 | if (insn[1].code != 0 || insn[1].src_reg != 0 || | |
482 | insn[1].dst_reg != 0 || insn[1].off != 0) { | |
483 | /* verifier must catch invalid insns */ | |
484 | pr_err("invalid BPF_LD_IMM64 insn\n"); | |
485 | return -EINVAL; | |
486 | } | |
487 | ||
606c88a8 DB |
488 | /* optimization: if imm64 is zero, use 'xor <dst>,<dst>' |
489 | * to save 7 bytes. | |
490 | */ | |
491 | if (insn[0].imm == 0 && insn[1].imm == 0) { | |
492 | b1 = add_2mod(0x48, dst_reg, dst_reg); | |
493 | b2 = 0x31; /* xor */ | |
494 | b3 = 0xC0; | |
495 | EMIT3(b1, b2, add_2reg(b3, dst_reg, dst_reg)); | |
496 | ||
497 | insn++; | |
498 | i++; | |
499 | break; | |
500 | } | |
501 | ||
02ab695b AS |
502 | /* movabsq %rax, imm64 */ |
503 | EMIT2(add_1mod(0x48, dst_reg), add_1reg(0xB8, dst_reg)); | |
504 | EMIT(insn[0].imm, 4); | |
505 | EMIT(insn[1].imm, 4); | |
506 | ||
507 | insn++; | |
508 | i++; | |
509 | break; | |
510 | ||
e430f34e | 511 | /* dst %= src, dst /= src, dst %= imm32, dst /= imm32 */ |
62258278 AS |
512 | case BPF_ALU | BPF_MOD | BPF_X: |
513 | case BPF_ALU | BPF_DIV | BPF_X: | |
514 | case BPF_ALU | BPF_MOD | BPF_K: | |
515 | case BPF_ALU | BPF_DIV | BPF_K: | |
516 | case BPF_ALU64 | BPF_MOD | BPF_X: | |
517 | case BPF_ALU64 | BPF_DIV | BPF_X: | |
518 | case BPF_ALU64 | BPF_MOD | BPF_K: | |
519 | case BPF_ALU64 | BPF_DIV | BPF_K: | |
520 | EMIT1(0x50); /* push rax */ | |
521 | EMIT1(0x52); /* push rdx */ | |
522 | ||
523 | if (BPF_SRC(insn->code) == BPF_X) | |
e430f34e AS |
524 | /* mov r11, src_reg */ |
525 | EMIT_mov(AUX_REG, src_reg); | |
62258278 | 526 | else |
e430f34e AS |
527 | /* mov r11, imm32 */ |
528 | EMIT3_off32(0x49, 0xC7, 0xC3, imm32); | |
62258278 | 529 | |
e430f34e AS |
530 | /* mov rax, dst_reg */ |
531 | EMIT_mov(BPF_REG_0, dst_reg); | |
62258278 AS |
532 | |
533 | /* xor edx, edx | |
534 | * equivalent to 'xor rdx, rdx', but one byte less | |
535 | */ | |
536 | EMIT2(0x31, 0xd2); | |
537 | ||
538 | if (BPF_SRC(insn->code) == BPF_X) { | |
e430f34e | 539 | /* if (src_reg == 0) return 0 */ |
62258278 AS |
540 | |
541 | /* cmp r11, 0 */ | |
542 | EMIT4(0x49, 0x83, 0xFB, 0x00); | |
543 | ||
544 | /* jne .+9 (skip over pop, pop, xor and jmp) */ | |
545 | EMIT2(X86_JNE, 1 + 1 + 2 + 5); | |
546 | EMIT1(0x5A); /* pop rdx */ | |
547 | EMIT1(0x58); /* pop rax */ | |
548 | EMIT2(0x31, 0xc0); /* xor eax, eax */ | |
549 | ||
550 | /* jmp cleanup_addr | |
551 | * addrs[i] - 11, because there are 11 bytes | |
552 | * after this insn: div, mov, pop, pop, mov | |
553 | */ | |
554 | jmp_offset = ctx->cleanup_addr - (addrs[i] - 11); | |
555 | EMIT1_off32(0xE9, jmp_offset); | |
556 | } | |
557 | ||
558 | if (BPF_CLASS(insn->code) == BPF_ALU64) | |
559 | /* div r11 */ | |
560 | EMIT3(0x49, 0xF7, 0xF3); | |
561 | else | |
562 | /* div r11d */ | |
563 | EMIT3(0x41, 0xF7, 0xF3); | |
564 | ||
565 | if (BPF_OP(insn->code) == BPF_MOD) | |
566 | /* mov r11, rdx */ | |
567 | EMIT3(0x49, 0x89, 0xD3); | |
568 | else | |
569 | /* mov r11, rax */ | |
570 | EMIT3(0x49, 0x89, 0xC3); | |
571 | ||
572 | EMIT1(0x5A); /* pop rdx */ | |
573 | EMIT1(0x58); /* pop rax */ | |
574 | ||
e430f34e AS |
575 | /* mov dst_reg, r11 */ |
576 | EMIT_mov(dst_reg, AUX_REG); | |
62258278 AS |
577 | break; |
578 | ||
579 | case BPF_ALU | BPF_MUL | BPF_K: | |
580 | case BPF_ALU | BPF_MUL | BPF_X: | |
581 | case BPF_ALU64 | BPF_MUL | BPF_K: | |
582 | case BPF_ALU64 | BPF_MUL | BPF_X: | |
583 | EMIT1(0x50); /* push rax */ | |
584 | EMIT1(0x52); /* push rdx */ | |
585 | ||
e430f34e AS |
586 | /* mov r11, dst_reg */ |
587 | EMIT_mov(AUX_REG, dst_reg); | |
62258278 AS |
588 | |
589 | if (BPF_SRC(insn->code) == BPF_X) | |
e430f34e AS |
590 | /* mov rax, src_reg */ |
591 | EMIT_mov(BPF_REG_0, src_reg); | |
62258278 | 592 | else |
e430f34e AS |
593 | /* mov rax, imm32 */ |
594 | EMIT3_off32(0x48, 0xC7, 0xC0, imm32); | |
62258278 AS |
595 | |
596 | if (BPF_CLASS(insn->code) == BPF_ALU64) | |
597 | EMIT1(add_1mod(0x48, AUX_REG)); | |
598 | else if (is_ereg(AUX_REG)) | |
599 | EMIT1(add_1mod(0x40, AUX_REG)); | |
600 | /* mul(q) r11 */ | |
601 | EMIT2(0xF7, add_1reg(0xE0, AUX_REG)); | |
602 | ||
603 | /* mov r11, rax */ | |
604 | EMIT_mov(AUX_REG, BPF_REG_0); | |
605 | ||
606 | EMIT1(0x5A); /* pop rdx */ | |
607 | EMIT1(0x58); /* pop rax */ | |
608 | ||
e430f34e AS |
609 | /* mov dst_reg, r11 */ |
610 | EMIT_mov(dst_reg, AUX_REG); | |
62258278 AS |
611 | break; |
612 | ||
613 | /* shifts */ | |
614 | case BPF_ALU | BPF_LSH | BPF_K: | |
615 | case BPF_ALU | BPF_RSH | BPF_K: | |
616 | case BPF_ALU | BPF_ARSH | BPF_K: | |
617 | case BPF_ALU64 | BPF_LSH | BPF_K: | |
618 | case BPF_ALU64 | BPF_RSH | BPF_K: | |
619 | case BPF_ALU64 | BPF_ARSH | BPF_K: | |
620 | if (BPF_CLASS(insn->code) == BPF_ALU64) | |
e430f34e AS |
621 | EMIT1(add_1mod(0x48, dst_reg)); |
622 | else if (is_ereg(dst_reg)) | |
623 | EMIT1(add_1mod(0x40, dst_reg)); | |
62258278 AS |
624 | |
625 | switch (BPF_OP(insn->code)) { | |
626 | case BPF_LSH: b3 = 0xE0; break; | |
627 | case BPF_RSH: b3 = 0xE8; break; | |
628 | case BPF_ARSH: b3 = 0xF8; break; | |
629 | } | |
e430f34e | 630 | EMIT3(0xC1, add_1reg(b3, dst_reg), imm32); |
62258278 AS |
631 | break; |
632 | ||
72b603ee AS |
633 | case BPF_ALU | BPF_LSH | BPF_X: |
634 | case BPF_ALU | BPF_RSH | BPF_X: | |
635 | case BPF_ALU | BPF_ARSH | BPF_X: | |
636 | case BPF_ALU64 | BPF_LSH | BPF_X: | |
637 | case BPF_ALU64 | BPF_RSH | BPF_X: | |
638 | case BPF_ALU64 | BPF_ARSH | BPF_X: | |
639 | ||
640 | /* check for bad case when dst_reg == rcx */ | |
641 | if (dst_reg == BPF_REG_4) { | |
642 | /* mov r11, dst_reg */ | |
643 | EMIT_mov(AUX_REG, dst_reg); | |
644 | dst_reg = AUX_REG; | |
645 | } | |
646 | ||
647 | if (src_reg != BPF_REG_4) { /* common case */ | |
648 | EMIT1(0x51); /* push rcx */ | |
649 | ||
650 | /* mov rcx, src_reg */ | |
651 | EMIT_mov(BPF_REG_4, src_reg); | |
652 | } | |
653 | ||
654 | /* shl %rax, %cl | shr %rax, %cl | sar %rax, %cl */ | |
655 | if (BPF_CLASS(insn->code) == BPF_ALU64) | |
656 | EMIT1(add_1mod(0x48, dst_reg)); | |
657 | else if (is_ereg(dst_reg)) | |
658 | EMIT1(add_1mod(0x40, dst_reg)); | |
659 | ||
660 | switch (BPF_OP(insn->code)) { | |
661 | case BPF_LSH: b3 = 0xE0; break; | |
662 | case BPF_RSH: b3 = 0xE8; break; | |
663 | case BPF_ARSH: b3 = 0xF8; break; | |
664 | } | |
665 | EMIT2(0xD3, add_1reg(b3, dst_reg)); | |
666 | ||
667 | if (src_reg != BPF_REG_4) | |
668 | EMIT1(0x59); /* pop rcx */ | |
669 | ||
670 | if (insn->dst_reg == BPF_REG_4) | |
671 | /* mov dst_reg, r11 */ | |
672 | EMIT_mov(insn->dst_reg, AUX_REG); | |
673 | break; | |
674 | ||
62258278 | 675 | case BPF_ALU | BPF_END | BPF_FROM_BE: |
e430f34e | 676 | switch (imm32) { |
62258278 AS |
677 | case 16: |
678 | /* emit 'ror %ax, 8' to swap lower 2 bytes */ | |
679 | EMIT1(0x66); | |
e430f34e | 680 | if (is_ereg(dst_reg)) |
62258278 | 681 | EMIT1(0x41); |
e430f34e | 682 | EMIT3(0xC1, add_1reg(0xC8, dst_reg), 8); |
343f845b AS |
683 | |
684 | /* emit 'movzwl eax, ax' */ | |
685 | if (is_ereg(dst_reg)) | |
686 | EMIT3(0x45, 0x0F, 0xB7); | |
687 | else | |
688 | EMIT2(0x0F, 0xB7); | |
689 | EMIT1(add_2reg(0xC0, dst_reg, dst_reg)); | |
62258278 AS |
690 | break; |
691 | case 32: | |
692 | /* emit 'bswap eax' to swap lower 4 bytes */ | |
e430f34e | 693 | if (is_ereg(dst_reg)) |
62258278 | 694 | EMIT2(0x41, 0x0F); |
0a14842f | 695 | else |
62258278 | 696 | EMIT1(0x0F); |
e430f34e | 697 | EMIT1(add_1reg(0xC8, dst_reg)); |
0a14842f | 698 | break; |
62258278 AS |
699 | case 64: |
700 | /* emit 'bswap rax' to swap 8 bytes */ | |
e430f34e AS |
701 | EMIT3(add_1mod(0x48, dst_reg), 0x0F, |
702 | add_1reg(0xC8, dst_reg)); | |
3b58908a ED |
703 | break; |
704 | } | |
62258278 AS |
705 | break; |
706 | ||
707 | case BPF_ALU | BPF_END | BPF_FROM_LE: | |
343f845b AS |
708 | switch (imm32) { |
709 | case 16: | |
710 | /* emit 'movzwl eax, ax' to zero extend 16-bit | |
711 | * into 64 bit | |
712 | */ | |
713 | if (is_ereg(dst_reg)) | |
714 | EMIT3(0x45, 0x0F, 0xB7); | |
715 | else | |
716 | EMIT2(0x0F, 0xB7); | |
717 | EMIT1(add_2reg(0xC0, dst_reg, dst_reg)); | |
718 | break; | |
719 | case 32: | |
720 | /* emit 'mov eax, eax' to clear upper 32-bits */ | |
721 | if (is_ereg(dst_reg)) | |
722 | EMIT1(0x45); | |
723 | EMIT2(0x89, add_2reg(0xC0, dst_reg, dst_reg)); | |
724 | break; | |
725 | case 64: | |
726 | /* nop */ | |
727 | break; | |
728 | } | |
62258278 AS |
729 | break; |
730 | ||
e430f34e | 731 | /* ST: *(u8*)(dst_reg + off) = imm */ |
62258278 | 732 | case BPF_ST | BPF_MEM | BPF_B: |
e430f34e | 733 | if (is_ereg(dst_reg)) |
62258278 AS |
734 | EMIT2(0x41, 0xC6); |
735 | else | |
736 | EMIT1(0xC6); | |
737 | goto st; | |
738 | case BPF_ST | BPF_MEM | BPF_H: | |
e430f34e | 739 | if (is_ereg(dst_reg)) |
62258278 AS |
740 | EMIT3(0x66, 0x41, 0xC7); |
741 | else | |
742 | EMIT2(0x66, 0xC7); | |
743 | goto st; | |
744 | case BPF_ST | BPF_MEM | BPF_W: | |
e430f34e | 745 | if (is_ereg(dst_reg)) |
62258278 AS |
746 | EMIT2(0x41, 0xC7); |
747 | else | |
748 | EMIT1(0xC7); | |
749 | goto st; | |
750 | case BPF_ST | BPF_MEM | BPF_DW: | |
e430f34e | 751 | EMIT2(add_1mod(0x48, dst_reg), 0xC7); |
62258278 AS |
752 | |
753 | st: if (is_imm8(insn->off)) | |
e430f34e | 754 | EMIT2(add_1reg(0x40, dst_reg), insn->off); |
62258278 | 755 | else |
e430f34e | 756 | EMIT1_off32(add_1reg(0x80, dst_reg), insn->off); |
62258278 | 757 | |
e430f34e | 758 | EMIT(imm32, bpf_size_to_x86_bytes(BPF_SIZE(insn->code))); |
62258278 AS |
759 | break; |
760 | ||
e430f34e | 761 | /* STX: *(u8*)(dst_reg + off) = src_reg */ |
62258278 AS |
762 | case BPF_STX | BPF_MEM | BPF_B: |
763 | /* emit 'mov byte ptr [rax + off], al' */ | |
e430f34e | 764 | if (is_ereg(dst_reg) || is_ereg(src_reg) || |
62258278 | 765 | /* have to add extra byte for x86 SIL, DIL regs */ |
e430f34e AS |
766 | src_reg == BPF_REG_1 || src_reg == BPF_REG_2) |
767 | EMIT2(add_2mod(0x40, dst_reg, src_reg), 0x88); | |
62258278 AS |
768 | else |
769 | EMIT1(0x88); | |
770 | goto stx; | |
771 | case BPF_STX | BPF_MEM | BPF_H: | |
e430f34e AS |
772 | if (is_ereg(dst_reg) || is_ereg(src_reg)) |
773 | EMIT3(0x66, add_2mod(0x40, dst_reg, src_reg), 0x89); | |
62258278 AS |
774 | else |
775 | EMIT2(0x66, 0x89); | |
776 | goto stx; | |
777 | case BPF_STX | BPF_MEM | BPF_W: | |
e430f34e AS |
778 | if (is_ereg(dst_reg) || is_ereg(src_reg)) |
779 | EMIT2(add_2mod(0x40, dst_reg, src_reg), 0x89); | |
62258278 AS |
780 | else |
781 | EMIT1(0x89); | |
782 | goto stx; | |
783 | case BPF_STX | BPF_MEM | BPF_DW: | |
e430f34e | 784 | EMIT2(add_2mod(0x48, dst_reg, src_reg), 0x89); |
62258278 | 785 | stx: if (is_imm8(insn->off)) |
e430f34e | 786 | EMIT2(add_2reg(0x40, dst_reg, src_reg), insn->off); |
62258278 | 787 | else |
e430f34e | 788 | EMIT1_off32(add_2reg(0x80, dst_reg, src_reg), |
62258278 AS |
789 | insn->off); |
790 | break; | |
791 | ||
e430f34e | 792 | /* LDX: dst_reg = *(u8*)(src_reg + off) */ |
62258278 AS |
793 | case BPF_LDX | BPF_MEM | BPF_B: |
794 | /* emit 'movzx rax, byte ptr [rax + off]' */ | |
e430f34e | 795 | EMIT3(add_2mod(0x48, src_reg, dst_reg), 0x0F, 0xB6); |
62258278 AS |
796 | goto ldx; |
797 | case BPF_LDX | BPF_MEM | BPF_H: | |
798 | /* emit 'movzx rax, word ptr [rax + off]' */ | |
e430f34e | 799 | EMIT3(add_2mod(0x48, src_reg, dst_reg), 0x0F, 0xB7); |
62258278 AS |
800 | goto ldx; |
801 | case BPF_LDX | BPF_MEM | BPF_W: | |
802 | /* emit 'mov eax, dword ptr [rax+0x14]' */ | |
e430f34e AS |
803 | if (is_ereg(dst_reg) || is_ereg(src_reg)) |
804 | EMIT2(add_2mod(0x40, src_reg, dst_reg), 0x8B); | |
62258278 AS |
805 | else |
806 | EMIT1(0x8B); | |
807 | goto ldx; | |
808 | case BPF_LDX | BPF_MEM | BPF_DW: | |
809 | /* emit 'mov rax, qword ptr [rax+0x14]' */ | |
e430f34e | 810 | EMIT2(add_2mod(0x48, src_reg, dst_reg), 0x8B); |
62258278 AS |
811 | ldx: /* if insn->off == 0 we can save one extra byte, but |
812 | * special case of x86 r13 which always needs an offset | |
813 | * is not worth the hassle | |
814 | */ | |
815 | if (is_imm8(insn->off)) | |
e430f34e | 816 | EMIT2(add_2reg(0x40, src_reg, dst_reg), insn->off); |
62258278 | 817 | else |
e430f34e | 818 | EMIT1_off32(add_2reg(0x80, src_reg, dst_reg), |
62258278 AS |
819 | insn->off); |
820 | break; | |
821 | ||
e430f34e | 822 | /* STX XADD: lock *(u32*)(dst_reg + off) += src_reg */ |
62258278 AS |
823 | case BPF_STX | BPF_XADD | BPF_W: |
824 | /* emit 'lock add dword ptr [rax + off], eax' */ | |
e430f34e AS |
825 | if (is_ereg(dst_reg) || is_ereg(src_reg)) |
826 | EMIT3(0xF0, add_2mod(0x40, dst_reg, src_reg), 0x01); | |
62258278 AS |
827 | else |
828 | EMIT2(0xF0, 0x01); | |
829 | goto xadd; | |
830 | case BPF_STX | BPF_XADD | BPF_DW: | |
e430f34e | 831 | EMIT3(0xF0, add_2mod(0x48, dst_reg, src_reg), 0x01); |
62258278 | 832 | xadd: if (is_imm8(insn->off)) |
e430f34e | 833 | EMIT2(add_2reg(0x40, dst_reg, src_reg), insn->off); |
62258278 | 834 | else |
e430f34e | 835 | EMIT1_off32(add_2reg(0x80, dst_reg, src_reg), |
62258278 AS |
836 | insn->off); |
837 | break; | |
838 | ||
839 | /* call */ | |
840 | case BPF_JMP | BPF_CALL: | |
e430f34e | 841 | func = (u8 *) __bpf_call_base + imm32; |
62258278 | 842 | jmp_offset = func - (image + addrs[i]); |
e0ee9c12 | 843 | if (seen_ld_abs) { |
4e10df9a AS |
844 | reload_skb_data = bpf_helper_changes_skb_data(func); |
845 | if (reload_skb_data) { | |
846 | EMIT1(0x57); /* push %rdi */ | |
847 | jmp_offset += 22; /* pop, mov, sub, mov */ | |
848 | } else { | |
849 | EMIT2(0x41, 0x52); /* push %r10 */ | |
850 | EMIT2(0x41, 0x51); /* push %r9 */ | |
851 | /* need to adjust jmp offset, since | |
852 | * pop %r9, pop %r10 take 4 bytes after call insn | |
853 | */ | |
854 | jmp_offset += 4; | |
855 | } | |
62258278 | 856 | } |
e430f34e | 857 | if (!imm32 || !is_simm32(jmp_offset)) { |
62258278 | 858 | pr_err("unsupported bpf func %d addr %p image %p\n", |
e430f34e | 859 | imm32, func, image); |
62258278 AS |
860 | return -EINVAL; |
861 | } | |
862 | EMIT1_off32(0xE8, jmp_offset); | |
e0ee9c12 | 863 | if (seen_ld_abs) { |
4e10df9a AS |
864 | if (reload_skb_data) { |
865 | EMIT1(0x5F); /* pop %rdi */ | |
866 | emit_load_skb_data_hlen(&prog); | |
867 | } else { | |
868 | EMIT2(0x41, 0x59); /* pop %r9 */ | |
869 | EMIT2(0x41, 0x5A); /* pop %r10 */ | |
870 | } | |
62258278 AS |
871 | } |
872 | break; | |
873 | ||
b52f00e6 AS |
874 | case BPF_JMP | BPF_CALL | BPF_X: |
875 | emit_bpf_tail_call(&prog); | |
876 | break; | |
877 | ||
62258278 AS |
878 | /* cond jump */ |
879 | case BPF_JMP | BPF_JEQ | BPF_X: | |
880 | case BPF_JMP | BPF_JNE | BPF_X: | |
881 | case BPF_JMP | BPF_JGT | BPF_X: | |
882 | case BPF_JMP | BPF_JGE | BPF_X: | |
883 | case BPF_JMP | BPF_JSGT | BPF_X: | |
884 | case BPF_JMP | BPF_JSGE | BPF_X: | |
e430f34e AS |
885 | /* cmp dst_reg, src_reg */ |
886 | EMIT3(add_2mod(0x48, dst_reg, src_reg), 0x39, | |
887 | add_2reg(0xC0, dst_reg, src_reg)); | |
62258278 AS |
888 | goto emit_cond_jmp; |
889 | ||
890 | case BPF_JMP | BPF_JSET | BPF_X: | |
e430f34e AS |
891 | /* test dst_reg, src_reg */ |
892 | EMIT3(add_2mod(0x48, dst_reg, src_reg), 0x85, | |
893 | add_2reg(0xC0, dst_reg, src_reg)); | |
62258278 AS |
894 | goto emit_cond_jmp; |
895 | ||
896 | case BPF_JMP | BPF_JSET | BPF_K: | |
e430f34e AS |
897 | /* test dst_reg, imm32 */ |
898 | EMIT1(add_1mod(0x48, dst_reg)); | |
899 | EMIT2_off32(0xF7, add_1reg(0xC0, dst_reg), imm32); | |
62258278 AS |
900 | goto emit_cond_jmp; |
901 | ||
902 | case BPF_JMP | BPF_JEQ | BPF_K: | |
903 | case BPF_JMP | BPF_JNE | BPF_K: | |
904 | case BPF_JMP | BPF_JGT | BPF_K: | |
905 | case BPF_JMP | BPF_JGE | BPF_K: | |
906 | case BPF_JMP | BPF_JSGT | BPF_K: | |
907 | case BPF_JMP | BPF_JSGE | BPF_K: | |
e430f34e AS |
908 | /* cmp dst_reg, imm8/32 */ |
909 | EMIT1(add_1mod(0x48, dst_reg)); | |
62258278 | 910 | |
e430f34e AS |
911 | if (is_imm8(imm32)) |
912 | EMIT3(0x83, add_1reg(0xF8, dst_reg), imm32); | |
62258278 | 913 | else |
e430f34e | 914 | EMIT2_off32(0x81, add_1reg(0xF8, dst_reg), imm32); |
62258278 AS |
915 | |
916 | emit_cond_jmp: /* convert BPF opcode to x86 */ | |
917 | switch (BPF_OP(insn->code)) { | |
918 | case BPF_JEQ: | |
919 | jmp_cond = X86_JE; | |
920 | break; | |
921 | case BPF_JSET: | |
922 | case BPF_JNE: | |
923 | jmp_cond = X86_JNE; | |
924 | break; | |
925 | case BPF_JGT: | |
926 | /* GT is unsigned '>', JA in x86 */ | |
927 | jmp_cond = X86_JA; | |
928 | break; | |
929 | case BPF_JGE: | |
930 | /* GE is unsigned '>=', JAE in x86 */ | |
931 | jmp_cond = X86_JAE; | |
932 | break; | |
933 | case BPF_JSGT: | |
934 | /* signed '>', GT in x86 */ | |
935 | jmp_cond = X86_JG; | |
936 | break; | |
937 | case BPF_JSGE: | |
938 | /* signed '>=', GE in x86 */ | |
939 | jmp_cond = X86_JGE; | |
940 | break; | |
941 | default: /* to silence gcc warning */ | |
942 | return -EFAULT; | |
943 | } | |
944 | jmp_offset = addrs[i + insn->off] - addrs[i]; | |
945 | if (is_imm8(jmp_offset)) { | |
946 | EMIT2(jmp_cond, jmp_offset); | |
947 | } else if (is_simm32(jmp_offset)) { | |
948 | EMIT2_off32(0x0F, jmp_cond + 0x10, jmp_offset); | |
949 | } else { | |
950 | pr_err("cond_jmp gen bug %llx\n", jmp_offset); | |
951 | return -EFAULT; | |
952 | } | |
953 | ||
954 | break; | |
0a14842f | 955 | |
62258278 AS |
956 | case BPF_JMP | BPF_JA: |
957 | jmp_offset = addrs[i + insn->off] - addrs[i]; | |
958 | if (!jmp_offset) | |
959 | /* optimize out nop jumps */ | |
960 | break; | |
961 | emit_jmp: | |
962 | if (is_imm8(jmp_offset)) { | |
963 | EMIT2(0xEB, jmp_offset); | |
964 | } else if (is_simm32(jmp_offset)) { | |
965 | EMIT1_off32(0xE9, jmp_offset); | |
966 | } else { | |
967 | pr_err("jmp gen bug %llx\n", jmp_offset); | |
968 | return -EFAULT; | |
969 | } | |
970 | break; | |
971 | ||
972 | case BPF_LD | BPF_IND | BPF_W: | |
973 | func = sk_load_word; | |
974 | goto common_load; | |
975 | case BPF_LD | BPF_ABS | BPF_W: | |
e430f34e | 976 | func = CHOOSE_LOAD_FUNC(imm32, sk_load_word); |
e0ee9c12 AS |
977 | common_load: |
978 | ctx->seen_ld_abs = seen_ld_abs = true; | |
62258278 AS |
979 | jmp_offset = func - (image + addrs[i]); |
980 | if (!func || !is_simm32(jmp_offset)) { | |
981 | pr_err("unsupported bpf func %d addr %p image %p\n", | |
e430f34e | 982 | imm32, func, image); |
62258278 AS |
983 | return -EINVAL; |
984 | } | |
985 | if (BPF_MODE(insn->code) == BPF_ABS) { | |
986 | /* mov %esi, imm32 */ | |
e430f34e | 987 | EMIT1_off32(0xBE, imm32); |
62258278 | 988 | } else { |
e430f34e AS |
989 | /* mov %rsi, src_reg */ |
990 | EMIT_mov(BPF_REG_2, src_reg); | |
991 | if (imm32) { | |
992 | if (is_imm8(imm32)) | |
62258278 | 993 | /* add %esi, imm8 */ |
e430f34e | 994 | EMIT3(0x83, 0xC6, imm32); |
0a14842f | 995 | else |
62258278 | 996 | /* add %esi, imm32 */ |
e430f34e | 997 | EMIT2_off32(0x81, 0xC6, imm32); |
0a14842f | 998 | } |
62258278 AS |
999 | } |
1000 | /* skb pointer is in R6 (%rbx), it will be copied into | |
1001 | * %rdi if skb_copy_bits() call is necessary. | |
1002 | * sk_load_* helpers also use %r10 and %r9d. | |
1003 | * See bpf_jit.S | |
1004 | */ | |
1005 | EMIT1_off32(0xE8, jmp_offset); /* call */ | |
1006 | break; | |
1007 | ||
1008 | case BPF_LD | BPF_IND | BPF_H: | |
1009 | func = sk_load_half; | |
1010 | goto common_load; | |
1011 | case BPF_LD | BPF_ABS | BPF_H: | |
e430f34e | 1012 | func = CHOOSE_LOAD_FUNC(imm32, sk_load_half); |
62258278 AS |
1013 | goto common_load; |
1014 | case BPF_LD | BPF_IND | BPF_B: | |
1015 | func = sk_load_byte; | |
1016 | goto common_load; | |
1017 | case BPF_LD | BPF_ABS | BPF_B: | |
e430f34e | 1018 | func = CHOOSE_LOAD_FUNC(imm32, sk_load_byte); |
62258278 AS |
1019 | goto common_load; |
1020 | ||
1021 | case BPF_JMP | BPF_EXIT: | |
769e0de6 | 1022 | if (seen_exit) { |
62258278 AS |
1023 | jmp_offset = ctx->cleanup_addr - addrs[i]; |
1024 | goto emit_jmp; | |
1025 | } | |
769e0de6 | 1026 | seen_exit = true; |
62258278 AS |
1027 | /* update cleanup_addr */ |
1028 | ctx->cleanup_addr = proglen; | |
1029 | /* mov rbx, qword ptr [rbp-X] */ | |
b52f00e6 | 1030 | EMIT3_off32(0x48, 0x8B, 0x9D, -STACKSIZE); |
62258278 | 1031 | /* mov r13, qword ptr [rbp-X] */ |
b52f00e6 | 1032 | EMIT3_off32(0x4C, 0x8B, 0xAD, -STACKSIZE + 8); |
62258278 | 1033 | /* mov r14, qword ptr [rbp-X] */ |
b52f00e6 | 1034 | EMIT3_off32(0x4C, 0x8B, 0xB5, -STACKSIZE + 16); |
62258278 | 1035 | /* mov r15, qword ptr [rbp-X] */ |
b52f00e6 | 1036 | EMIT3_off32(0x4C, 0x8B, 0xBD, -STACKSIZE + 24); |
62258278 AS |
1037 | |
1038 | EMIT1(0xC9); /* leave */ | |
1039 | EMIT1(0xC3); /* ret */ | |
1040 | break; | |
1041 | ||
f3c2af7b | 1042 | default: |
62258278 AS |
1043 | /* By design x64 JIT should support all BPF instructions |
1044 | * This error will be seen if new instruction was added | |
1045 | * to interpreter, but not to JIT | |
7ae457c1 | 1046 | * or if there is junk in bpf_prog |
62258278 AS |
1047 | */ |
1048 | pr_err("bpf_jit: unknown opcode %02x\n", insn->code); | |
f3c2af7b AS |
1049 | return -EINVAL; |
1050 | } | |
62258278 | 1051 | |
f3c2af7b | 1052 | ilen = prog - temp; |
e0ee9c12 AS |
1053 | if (ilen > BPF_MAX_INSN_SIZE) { |
1054 | pr_err("bpf_jit_compile fatal insn size error\n"); | |
1055 | return -EFAULT; | |
1056 | } | |
1057 | ||
f3c2af7b AS |
1058 | if (image) { |
1059 | if (unlikely(proglen + ilen > oldproglen)) { | |
62258278 | 1060 | pr_err("bpf_jit_compile fatal error\n"); |
f3c2af7b | 1061 | return -EFAULT; |
0a14842f | 1062 | } |
f3c2af7b | 1063 | memcpy(image + proglen, temp, ilen); |
0a14842f | 1064 | } |
f3c2af7b AS |
1065 | proglen += ilen; |
1066 | addrs[i] = proglen; | |
1067 | prog = temp; | |
1068 | } | |
f3c2af7b AS |
1069 | return proglen; |
1070 | } | |
1071 | ||
7ae457c1 | 1072 | void bpf_jit_compile(struct bpf_prog *prog) |
62258278 AS |
1073 | { |
1074 | } | |
1075 | ||
7ae457c1 | 1076 | void bpf_int_jit_compile(struct bpf_prog *prog) |
f3c2af7b AS |
1077 | { |
1078 | struct bpf_binary_header *header = NULL; | |
1079 | int proglen, oldproglen = 0; | |
1080 | struct jit_context ctx = {}; | |
1081 | u8 *image = NULL; | |
1082 | int *addrs; | |
1083 | int pass; | |
1084 | int i; | |
1085 | ||
1086 | if (!bpf_jit_enable) | |
1087 | return; | |
0a14842f | 1088 | |
f3c2af7b AS |
1089 | if (!prog || !prog->len) |
1090 | return; | |
1091 | ||
1092 | addrs = kmalloc(prog->len * sizeof(*addrs), GFP_KERNEL); | |
1093 | if (!addrs) | |
1094 | return; | |
1095 | ||
1096 | /* Before first pass, make a rough estimation of addrs[] | |
1097 | * each bpf instruction is translated to less than 64 bytes | |
1098 | */ | |
1099 | for (proglen = 0, i = 0; i < prog->len; i++) { | |
1100 | proglen += 64; | |
1101 | addrs[i] = proglen; | |
1102 | } | |
1103 | ctx.cleanup_addr = proglen; | |
f3c2af7b | 1104 | |
3f7352bf AS |
1105 | /* JITed image shrinks with every pass and the loop iterates |
1106 | * until the image stops shrinking. Very large bpf programs | |
1107 | * may converge on the last pass. In such case do one more | |
1108 | * pass to emit the final image | |
1109 | */ | |
1110 | for (pass = 0; pass < 10 || image; pass++) { | |
f3c2af7b AS |
1111 | proglen = do_jit(prog, addrs, image, oldproglen, &ctx); |
1112 | if (proglen <= 0) { | |
1113 | image = NULL; | |
1114 | if (header) | |
738cbe72 | 1115 | bpf_jit_binary_free(header); |
f3c2af7b AS |
1116 | goto out; |
1117 | } | |
0a14842f | 1118 | if (image) { |
e0ee9c12 | 1119 | if (proglen != oldproglen) { |
f3c2af7b AS |
1120 | pr_err("bpf_jit: proglen=%d != oldproglen=%d\n", |
1121 | proglen, oldproglen); | |
e0ee9c12 AS |
1122 | goto out; |
1123 | } | |
0a14842f ED |
1124 | break; |
1125 | } | |
1126 | if (proglen == oldproglen) { | |
738cbe72 DB |
1127 | header = bpf_jit_binary_alloc(proglen, &image, |
1128 | 1, jit_fill_hole); | |
314beb9b | 1129 | if (!header) |
0a14842f ED |
1130 | goto out; |
1131 | } | |
1132 | oldproglen = proglen; | |
1133 | } | |
79617801 | 1134 | |
0a14842f | 1135 | if (bpf_jit_enable > 1) |
485d6511 | 1136 | bpf_jit_dump(prog->len, proglen, pass + 1, image); |
0a14842f ED |
1137 | |
1138 | if (image) { | |
314beb9b ED |
1139 | bpf_flush_icache(header, image + proglen); |
1140 | set_memory_ro((unsigned long)header, header->pages); | |
f3c2af7b | 1141 | prog->bpf_func = (void *)image; |
a91263d5 | 1142 | prog->jited = 1; |
0a14842f ED |
1143 | } |
1144 | out: | |
1145 | kfree(addrs); | |
0a14842f ED |
1146 | } |
1147 | ||
60a3b225 | 1148 | void bpf_jit_free(struct bpf_prog *fp) |
d45ed4a4 | 1149 | { |
d45ed4a4 AS |
1150 | unsigned long addr = (unsigned long)fp->bpf_func & PAGE_MASK; |
1151 | struct bpf_binary_header *header = (void *)addr; | |
1152 | ||
60a3b225 DB |
1153 | if (!fp->jited) |
1154 | goto free_filter; | |
1155 | ||
d45ed4a4 | 1156 | set_memory_rw(addr, header->pages); |
738cbe72 | 1157 | bpf_jit_binary_free(header); |
d45ed4a4 | 1158 | |
60a3b225 DB |
1159 | free_filter: |
1160 | bpf_prog_unlock_free(fp); | |
0a14842f | 1161 | } |