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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> |
d1163651 | 15 | #include <asm/set_memory.h> |
b52f00e6 | 16 | #include <linux/bpf.h> |
0a14842f | 17 | |
0a14842f ED |
18 | int bpf_jit_enable __read_mostly; |
19 | ||
20 | /* | |
21 | * assembly code in arch/x86/net/bpf_jit.S | |
22 | */ | |
62258278 | 23 | extern u8 sk_load_word[], sk_load_half[], sk_load_byte[]; |
a998d434 | 24 | extern u8 sk_load_word_positive_offset[], sk_load_half_positive_offset[]; |
62258278 | 25 | extern u8 sk_load_byte_positive_offset[]; |
a998d434 | 26 | extern u8 sk_load_word_negative_offset[], sk_load_half_negative_offset[]; |
62258278 | 27 | extern u8 sk_load_byte_negative_offset[]; |
0a14842f | 28 | |
5cccc702 | 29 | static u8 *emit_code(u8 *ptr, u32 bytes, unsigned int len) |
0a14842f ED |
30 | { |
31 | if (len == 1) | |
32 | *ptr = bytes; | |
33 | else if (len == 2) | |
34 | *(u16 *)ptr = bytes; | |
35 | else { | |
36 | *(u32 *)ptr = bytes; | |
37 | barrier(); | |
38 | } | |
39 | return ptr + len; | |
40 | } | |
41 | ||
b52f00e6 AS |
42 | #define EMIT(bytes, len) \ |
43 | do { prog = emit_code(prog, bytes, len); cnt += len; } while (0) | |
0a14842f ED |
44 | |
45 | #define EMIT1(b1) EMIT(b1, 1) | |
46 | #define EMIT2(b1, b2) EMIT((b1) + ((b2) << 8), 2) | |
47 | #define EMIT3(b1, b2, b3) EMIT((b1) + ((b2) << 8) + ((b3) << 16), 3) | |
48 | #define EMIT4(b1, b2, b3, b4) EMIT((b1) + ((b2) << 8) + ((b3) << 16) + ((b4) << 24), 4) | |
62258278 AS |
49 | #define EMIT1_off32(b1, off) \ |
50 | do {EMIT1(b1); EMIT(off, 4); } while (0) | |
51 | #define EMIT2_off32(b1, b2, off) \ | |
52 | do {EMIT2(b1, b2); EMIT(off, 4); } while (0) | |
53 | #define EMIT3_off32(b1, b2, b3, off) \ | |
54 | do {EMIT3(b1, b2, b3); EMIT(off, 4); } while (0) | |
55 | #define EMIT4_off32(b1, b2, b3, b4, off) \ | |
56 | do {EMIT4(b1, b2, b3, b4); EMIT(off, 4); } while (0) | |
0a14842f | 57 | |
5cccc702 | 58 | static bool is_imm8(int value) |
0a14842f ED |
59 | { |
60 | return value <= 127 && value >= -128; | |
61 | } | |
62 | ||
5cccc702 | 63 | static bool is_simm32(s64 value) |
0a14842f | 64 | { |
62258278 | 65 | return value == (s64) (s32) value; |
0a14842f ED |
66 | } |
67 | ||
e430f34e AS |
68 | /* mov dst, src */ |
69 | #define EMIT_mov(DST, SRC) \ | |
70 | do {if (DST != SRC) \ | |
71 | EMIT3(add_2mod(0x48, DST, SRC), 0x89, add_2reg(0xC0, DST, SRC)); \ | |
62258278 AS |
72 | } while (0) |
73 | ||
74 | static int bpf_size_to_x86_bytes(int bpf_size) | |
75 | { | |
76 | if (bpf_size == BPF_W) | |
77 | return 4; | |
78 | else if (bpf_size == BPF_H) | |
79 | return 2; | |
80 | else if (bpf_size == BPF_B) | |
81 | return 1; | |
82 | else if (bpf_size == BPF_DW) | |
83 | return 4; /* imm32 */ | |
84 | else | |
85 | return 0; | |
86 | } | |
0a14842f ED |
87 | |
88 | /* list of x86 cond jumps opcodes (. + s8) | |
89 | * Add 0x10 (and an extra 0x0f) to generate far jumps (. + s32) | |
90 | */ | |
91 | #define X86_JB 0x72 | |
92 | #define X86_JAE 0x73 | |
93 | #define X86_JE 0x74 | |
94 | #define X86_JNE 0x75 | |
95 | #define X86_JBE 0x76 | |
96 | #define X86_JA 0x77 | |
62258278 AS |
97 | #define X86_JGE 0x7D |
98 | #define X86_JG 0x7F | |
0a14842f | 99 | |
5cccc702 | 100 | static void bpf_flush_icache(void *start, void *end) |
0a14842f ED |
101 | { |
102 | mm_segment_t old_fs = get_fs(); | |
103 | ||
104 | set_fs(KERNEL_DS); | |
105 | smp_wmb(); | |
106 | flush_icache_range((unsigned long)start, (unsigned long)end); | |
107 | set_fs(old_fs); | |
108 | } | |
109 | ||
a998d434 JS |
110 | #define CHOOSE_LOAD_FUNC(K, func) \ |
111 | ((int)K < 0 ? ((int)K >= SKF_LL_OFF ? func##_negative_offset : func) : func##_positive_offset) | |
0a14842f | 112 | |
62258278 | 113 | /* pick a register outside of BPF range for JIT internal work */ |
959a7579 | 114 | #define AUX_REG (MAX_BPF_JIT_REG + 1) |
62258278 | 115 | |
959a7579 DB |
116 | /* The following table maps BPF registers to x64 registers. |
117 | * | |
118 | * x64 register r12 is unused, since if used as base address | |
119 | * register in load/store instructions, it always needs an | |
120 | * extra byte of encoding and is callee saved. | |
121 | * | |
122 | * r9 caches skb->len - skb->data_len | |
123 | * r10 caches skb->data, and used for blinding (if enabled) | |
62258278 AS |
124 | */ |
125 | static const int reg2hex[] = { | |
126 | [BPF_REG_0] = 0, /* rax */ | |
127 | [BPF_REG_1] = 7, /* rdi */ | |
128 | [BPF_REG_2] = 6, /* rsi */ | |
129 | [BPF_REG_3] = 2, /* rdx */ | |
130 | [BPF_REG_4] = 1, /* rcx */ | |
131 | [BPF_REG_5] = 0, /* r8 */ | |
132 | [BPF_REG_6] = 3, /* rbx callee saved */ | |
133 | [BPF_REG_7] = 5, /* r13 callee saved */ | |
134 | [BPF_REG_8] = 6, /* r14 callee saved */ | |
135 | [BPF_REG_9] = 7, /* r15 callee saved */ | |
136 | [BPF_REG_FP] = 5, /* rbp readonly */ | |
959a7579 | 137 | [BPF_REG_AX] = 2, /* r10 temp register */ |
62258278 AS |
138 | [AUX_REG] = 3, /* r11 temp register */ |
139 | }; | |
140 | ||
141 | /* is_ereg() == true if BPF register 'reg' maps to x64 r8..r15 | |
142 | * which need extra byte of encoding. | |
143 | * rax,rcx,...,rbp have simpler encoding | |
144 | */ | |
5cccc702 | 145 | static bool is_ereg(u32 reg) |
62258278 | 146 | { |
d148134b JP |
147 | return (1 << reg) & (BIT(BPF_REG_5) | |
148 | BIT(AUX_REG) | | |
149 | BIT(BPF_REG_7) | | |
150 | BIT(BPF_REG_8) | | |
959a7579 DB |
151 | BIT(BPF_REG_9) | |
152 | BIT(BPF_REG_AX)); | |
62258278 AS |
153 | } |
154 | ||
155 | /* add modifiers if 'reg' maps to x64 registers r8..r15 */ | |
5cccc702 | 156 | static u8 add_1mod(u8 byte, u32 reg) |
62258278 AS |
157 | { |
158 | if (is_ereg(reg)) | |
159 | byte |= 1; | |
160 | return byte; | |
161 | } | |
162 | ||
5cccc702 | 163 | static u8 add_2mod(u8 byte, u32 r1, u32 r2) |
62258278 AS |
164 | { |
165 | if (is_ereg(r1)) | |
166 | byte |= 1; | |
167 | if (is_ereg(r2)) | |
168 | byte |= 4; | |
169 | return byte; | |
170 | } | |
171 | ||
e430f34e | 172 | /* encode 'dst_reg' register into x64 opcode 'byte' */ |
5cccc702 | 173 | static u8 add_1reg(u8 byte, u32 dst_reg) |
62258278 | 174 | { |
e430f34e | 175 | return byte + reg2hex[dst_reg]; |
62258278 AS |
176 | } |
177 | ||
e430f34e | 178 | /* encode 'dst_reg' and 'src_reg' registers into x64 opcode 'byte' */ |
5cccc702 | 179 | static u8 add_2reg(u8 byte, u32 dst_reg, u32 src_reg) |
62258278 | 180 | { |
e430f34e | 181 | return byte + reg2hex[dst_reg] + (reg2hex[src_reg] << 3); |
62258278 AS |
182 | } |
183 | ||
738cbe72 DB |
184 | static void jit_fill_hole(void *area, unsigned int size) |
185 | { | |
186 | /* fill whole space with int3 instructions */ | |
187 | memset(area, 0xcc, size); | |
188 | } | |
189 | ||
f3c2af7b | 190 | struct jit_context { |
769e0de6 | 191 | int cleanup_addr; /* epilogue code offset */ |
62258278 | 192 | bool seen_ld_abs; |
959a7579 | 193 | bool seen_ax_reg; |
f3c2af7b AS |
194 | }; |
195 | ||
e0ee9c12 AS |
196 | /* maximum number of bytes emitted while JITing one eBPF insn */ |
197 | #define BPF_MAX_INSN_SIZE 128 | |
198 | #define BPF_INSN_SAFETY 64 | |
199 | ||
b52f00e6 AS |
200 | #define STACKSIZE \ |
201 | (MAX_BPF_STACK + \ | |
202 | 32 /* space for rbx, r13, r14, r15 */ + \ | |
203 | 8 /* space for skb_copy_bits() buffer */) | |
204 | ||
8b614aeb | 205 | #define PROLOGUE_SIZE 48 |
b52f00e6 AS |
206 | |
207 | /* emit x64 prologue code for BPF program and check it's size. | |
208 | * bpf_tail_call helper will skip it while jumping into another program | |
209 | */ | |
210 | static void emit_prologue(u8 **pprog) | |
0a14842f | 211 | { |
b52f00e6 AS |
212 | u8 *prog = *pprog; |
213 | int cnt = 0; | |
0a14842f | 214 | |
62258278 AS |
215 | EMIT1(0x55); /* push rbp */ |
216 | EMIT3(0x48, 0x89, 0xE5); /* mov rbp,rsp */ | |
0a14842f | 217 | |
b52f00e6 AS |
218 | /* sub rsp, STACKSIZE */ |
219 | EMIT3_off32(0x48, 0x81, 0xEC, STACKSIZE); | |
62258278 AS |
220 | |
221 | /* all classic BPF filters use R6(rbx) save it */ | |
222 | ||
223 | /* mov qword ptr [rbp-X],rbx */ | |
b52f00e6 | 224 | EMIT3_off32(0x48, 0x89, 0x9D, -STACKSIZE); |
62258278 | 225 | |
8fb575ca | 226 | /* bpf_convert_filter() maps classic BPF register X to R7 and uses R8 |
62258278 AS |
227 | * as temporary, so all tcpdump filters need to spill/fill R7(r13) and |
228 | * R8(r14). R9(r15) spill could be made conditional, but there is only | |
229 | * one 'bpf_error' return path out of helper functions inside bpf_jit.S | |
230 | * The overhead of extra spill is negligible for any filter other | |
231 | * than synthetic ones. Therefore not worth adding complexity. | |
232 | */ | |
233 | ||
234 | /* mov qword ptr [rbp-X],r13 */ | |
b52f00e6 | 235 | EMIT3_off32(0x4C, 0x89, 0xAD, -STACKSIZE + 8); |
62258278 | 236 | /* mov qword ptr [rbp-X],r14 */ |
b52f00e6 | 237 | EMIT3_off32(0x4C, 0x89, 0xB5, -STACKSIZE + 16); |
62258278 | 238 | /* mov qword ptr [rbp-X],r15 */ |
b52f00e6 | 239 | EMIT3_off32(0x4C, 0x89, 0xBD, -STACKSIZE + 24); |
62258278 | 240 | |
8b614aeb DB |
241 | /* Clear the tail call counter (tail_call_cnt): for eBPF tail calls |
242 | * we need to reset the counter to 0. It's done in two instructions, | |
243 | * resetting rax register to 0 (xor on eax gets 0 extended), and | |
244 | * moving it to the counter location. | |
245 | */ | |
62258278 | 246 | |
8b614aeb DB |
247 | /* xor eax, eax */ |
248 | EMIT2(0x31, 0xc0); | |
249 | /* mov qword ptr [rbp-X], rax */ | |
b52f00e6 AS |
250 | EMIT3_off32(0x48, 0x89, 0x85, -STACKSIZE + 32); |
251 | ||
252 | BUILD_BUG_ON(cnt != PROLOGUE_SIZE); | |
253 | *pprog = prog; | |
254 | } | |
255 | ||
256 | /* generate the following code: | |
257 | * ... bpf_tail_call(void *ctx, struct bpf_array *array, u64 index) ... | |
258 | * if (index >= array->map.max_entries) | |
259 | * goto out; | |
260 | * if (++tail_call_cnt > MAX_TAIL_CALL_CNT) | |
261 | * goto out; | |
2a36f0b9 | 262 | * prog = array->ptrs[index]; |
b52f00e6 AS |
263 | * if (prog == NULL) |
264 | * goto out; | |
265 | * goto *(prog->bpf_func + prologue_size); | |
266 | * out: | |
267 | */ | |
268 | static void emit_bpf_tail_call(u8 **pprog) | |
269 | { | |
270 | u8 *prog = *pprog; | |
271 | int label1, label2, label3; | |
272 | int cnt = 0; | |
273 | ||
274 | /* rdi - pointer to ctx | |
275 | * rsi - pointer to bpf_array | |
276 | * rdx - index in bpf_array | |
277 | */ | |
278 | ||
279 | /* if (index >= array->map.max_entries) | |
280 | * goto out; | |
281 | */ | |
282 | EMIT4(0x48, 0x8B, 0x46, /* mov rax, qword ptr [rsi + 16] */ | |
283 | offsetof(struct bpf_array, map.max_entries)); | |
284 | EMIT3(0x48, 0x39, 0xD0); /* cmp rax, rdx */ | |
2482abb9 | 285 | #define OFFSET1 47 /* number of bytes to jump */ |
b52f00e6 AS |
286 | EMIT2(X86_JBE, OFFSET1); /* jbe out */ |
287 | label1 = cnt; | |
288 | ||
289 | /* if (tail_call_cnt > MAX_TAIL_CALL_CNT) | |
290 | * goto out; | |
291 | */ | |
292 | EMIT2_off32(0x8B, 0x85, -STACKSIZE + 36); /* mov eax, dword ptr [rbp - 516] */ | |
293 | EMIT3(0x83, 0xF8, MAX_TAIL_CALL_CNT); /* cmp eax, MAX_TAIL_CALL_CNT */ | |
2482abb9 | 294 | #define OFFSET2 36 |
b52f00e6 AS |
295 | EMIT2(X86_JA, OFFSET2); /* ja out */ |
296 | label2 = cnt; | |
297 | EMIT3(0x83, 0xC0, 0x01); /* add eax, 1 */ | |
298 | EMIT2_off32(0x89, 0x85, -STACKSIZE + 36); /* mov dword ptr [rbp - 516], eax */ | |
299 | ||
2a36f0b9 | 300 | /* prog = array->ptrs[index]; */ |
2482abb9 | 301 | EMIT4_off32(0x48, 0x8D, 0x84, 0xD6, /* lea rax, [rsi + rdx * 8 + offsetof(...)] */ |
2a36f0b9 | 302 | offsetof(struct bpf_array, ptrs)); |
b52f00e6 AS |
303 | EMIT3(0x48, 0x8B, 0x00); /* mov rax, qword ptr [rax] */ |
304 | ||
305 | /* if (prog == NULL) | |
306 | * goto out; | |
307 | */ | |
308 | EMIT4(0x48, 0x83, 0xF8, 0x00); /* cmp rax, 0 */ | |
309 | #define OFFSET3 10 | |
310 | EMIT2(X86_JE, OFFSET3); /* je out */ | |
311 | label3 = cnt; | |
312 | ||
313 | /* goto *(prog->bpf_func + prologue_size); */ | |
314 | EMIT4(0x48, 0x8B, 0x40, /* mov rax, qword ptr [rax + 32] */ | |
315 | offsetof(struct bpf_prog, bpf_func)); | |
316 | EMIT4(0x48, 0x83, 0xC0, PROLOGUE_SIZE); /* add rax, prologue_size */ | |
317 | ||
318 | /* now we're ready to jump into next BPF program | |
319 | * rdi == ctx (1st arg) | |
320 | * rax == prog->bpf_func + prologue_size | |
321 | */ | |
322 | EMIT2(0xFF, 0xE0); /* jmp rax */ | |
323 | ||
324 | /* out: */ | |
325 | BUILD_BUG_ON(cnt - label1 != OFFSET1); | |
326 | BUILD_BUG_ON(cnt - label2 != OFFSET2); | |
327 | BUILD_BUG_ON(cnt - label3 != OFFSET3); | |
328 | *pprog = prog; | |
329 | } | |
330 | ||
4e10df9a AS |
331 | |
332 | static void emit_load_skb_data_hlen(u8 **pprog) | |
333 | { | |
334 | u8 *prog = *pprog; | |
335 | int cnt = 0; | |
336 | ||
337 | /* r9d = skb->len - skb->data_len (headlen) | |
338 | * r10 = skb->data | |
339 | */ | |
340 | /* mov %r9d, off32(%rdi) */ | |
341 | EMIT3_off32(0x44, 0x8b, 0x8f, offsetof(struct sk_buff, len)); | |
342 | ||
343 | /* sub %r9d, off32(%rdi) */ | |
344 | EMIT3_off32(0x44, 0x2b, 0x8f, offsetof(struct sk_buff, data_len)); | |
345 | ||
346 | /* mov %r10, off32(%rdi) */ | |
347 | EMIT3_off32(0x4c, 0x8b, 0x97, offsetof(struct sk_buff, data)); | |
348 | *pprog = prog; | |
349 | } | |
350 | ||
b52f00e6 AS |
351 | static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image, |
352 | int oldproglen, struct jit_context *ctx) | |
353 | { | |
354 | struct bpf_insn *insn = bpf_prog->insnsi; | |
355 | int insn_cnt = bpf_prog->len; | |
356 | bool seen_ld_abs = ctx->seen_ld_abs | (oldproglen == 0); | |
959a7579 | 357 | bool seen_ax_reg = ctx->seen_ax_reg | (oldproglen == 0); |
b52f00e6 AS |
358 | bool seen_exit = false; |
359 | u8 temp[BPF_MAX_INSN_SIZE + BPF_INSN_SAFETY]; | |
360 | int i, cnt = 0; | |
361 | int proglen = 0; | |
362 | u8 *prog = temp; | |
363 | ||
364 | emit_prologue(&prog); | |
365 | ||
4e10df9a AS |
366 | if (seen_ld_abs) |
367 | emit_load_skb_data_hlen(&prog); | |
62258278 AS |
368 | |
369 | for (i = 0; i < insn_cnt; i++, insn++) { | |
e430f34e AS |
370 | const s32 imm32 = insn->imm; |
371 | u32 dst_reg = insn->dst_reg; | |
372 | u32 src_reg = insn->src_reg; | |
62258278 AS |
373 | u8 b1 = 0, b2 = 0, b3 = 0; |
374 | s64 jmp_offset; | |
375 | u8 jmp_cond; | |
4e10df9a | 376 | bool reload_skb_data; |
62258278 AS |
377 | int ilen; |
378 | u8 *func; | |
379 | ||
959a7579 DB |
380 | if (dst_reg == BPF_REG_AX || src_reg == BPF_REG_AX) |
381 | ctx->seen_ax_reg = seen_ax_reg = true; | |
382 | ||
62258278 AS |
383 | switch (insn->code) { |
384 | /* ALU */ | |
385 | case BPF_ALU | BPF_ADD | BPF_X: | |
386 | case BPF_ALU | BPF_SUB | BPF_X: | |
387 | case BPF_ALU | BPF_AND | BPF_X: | |
388 | case BPF_ALU | BPF_OR | BPF_X: | |
389 | case BPF_ALU | BPF_XOR | BPF_X: | |
390 | case BPF_ALU64 | BPF_ADD | BPF_X: | |
391 | case BPF_ALU64 | BPF_SUB | BPF_X: | |
392 | case BPF_ALU64 | BPF_AND | BPF_X: | |
393 | case BPF_ALU64 | BPF_OR | BPF_X: | |
394 | case BPF_ALU64 | BPF_XOR | BPF_X: | |
395 | switch (BPF_OP(insn->code)) { | |
396 | case BPF_ADD: b2 = 0x01; break; | |
397 | case BPF_SUB: b2 = 0x29; break; | |
398 | case BPF_AND: b2 = 0x21; break; | |
399 | case BPF_OR: b2 = 0x09; break; | |
400 | case BPF_XOR: b2 = 0x31; break; | |
0a14842f | 401 | } |
62258278 | 402 | if (BPF_CLASS(insn->code) == BPF_ALU64) |
e430f34e AS |
403 | EMIT1(add_2mod(0x48, dst_reg, src_reg)); |
404 | else if (is_ereg(dst_reg) || is_ereg(src_reg)) | |
405 | EMIT1(add_2mod(0x40, dst_reg, src_reg)); | |
406 | EMIT2(b2, add_2reg(0xC0, dst_reg, src_reg)); | |
62258278 | 407 | break; |
0a14842f | 408 | |
e430f34e | 409 | /* mov dst, src */ |
62258278 | 410 | case BPF_ALU64 | BPF_MOV | BPF_X: |
e430f34e | 411 | EMIT_mov(dst_reg, src_reg); |
0a14842f | 412 | break; |
0a14842f | 413 | |
e430f34e | 414 | /* mov32 dst, src */ |
62258278 | 415 | case BPF_ALU | BPF_MOV | BPF_X: |
e430f34e AS |
416 | if (is_ereg(dst_reg) || is_ereg(src_reg)) |
417 | EMIT1(add_2mod(0x40, dst_reg, src_reg)); | |
418 | EMIT2(0x89, add_2reg(0xC0, dst_reg, src_reg)); | |
62258278 | 419 | break; |
0a14842f | 420 | |
e430f34e | 421 | /* neg dst */ |
62258278 AS |
422 | case BPF_ALU | BPF_NEG: |
423 | case BPF_ALU64 | BPF_NEG: | |
424 | if (BPF_CLASS(insn->code) == BPF_ALU64) | |
e430f34e AS |
425 | EMIT1(add_1mod(0x48, dst_reg)); |
426 | else if (is_ereg(dst_reg)) | |
427 | EMIT1(add_1mod(0x40, dst_reg)); | |
428 | EMIT2(0xF7, add_1reg(0xD8, dst_reg)); | |
62258278 AS |
429 | break; |
430 | ||
431 | case BPF_ALU | BPF_ADD | BPF_K: | |
432 | case BPF_ALU | BPF_SUB | BPF_K: | |
433 | case BPF_ALU | BPF_AND | BPF_K: | |
434 | case BPF_ALU | BPF_OR | BPF_K: | |
435 | case BPF_ALU | BPF_XOR | BPF_K: | |
436 | case BPF_ALU64 | BPF_ADD | BPF_K: | |
437 | case BPF_ALU64 | BPF_SUB | BPF_K: | |
438 | case BPF_ALU64 | BPF_AND | BPF_K: | |
439 | case BPF_ALU64 | BPF_OR | BPF_K: | |
440 | case BPF_ALU64 | BPF_XOR | BPF_K: | |
441 | if (BPF_CLASS(insn->code) == BPF_ALU64) | |
e430f34e AS |
442 | EMIT1(add_1mod(0x48, dst_reg)); |
443 | else if (is_ereg(dst_reg)) | |
444 | EMIT1(add_1mod(0x40, dst_reg)); | |
62258278 AS |
445 | |
446 | switch (BPF_OP(insn->code)) { | |
447 | case BPF_ADD: b3 = 0xC0; break; | |
448 | case BPF_SUB: b3 = 0xE8; break; | |
449 | case BPF_AND: b3 = 0xE0; break; | |
450 | case BPF_OR: b3 = 0xC8; break; | |
451 | case BPF_XOR: b3 = 0xF0; break; | |
452 | } | |
453 | ||
e430f34e AS |
454 | if (is_imm8(imm32)) |
455 | EMIT3(0x83, add_1reg(b3, dst_reg), imm32); | |
62258278 | 456 | else |
e430f34e | 457 | EMIT2_off32(0x81, add_1reg(b3, dst_reg), imm32); |
62258278 AS |
458 | break; |
459 | ||
460 | case BPF_ALU64 | BPF_MOV | BPF_K: | |
461 | /* optimization: if imm32 is positive, | |
462 | * use 'mov eax, imm32' (which zero-extends imm32) | |
463 | * to save 2 bytes | |
464 | */ | |
e430f34e | 465 | if (imm32 < 0) { |
62258278 | 466 | /* 'mov rax, imm32' sign extends imm32 */ |
e430f34e | 467 | b1 = add_1mod(0x48, dst_reg); |
62258278 AS |
468 | b2 = 0xC7; |
469 | b3 = 0xC0; | |
e430f34e | 470 | EMIT3_off32(b1, b2, add_1reg(b3, dst_reg), imm32); |
0a14842f | 471 | break; |
62258278 AS |
472 | } |
473 | ||
474 | case BPF_ALU | BPF_MOV | BPF_K: | |
606c88a8 DB |
475 | /* optimization: if imm32 is zero, use 'xor <dst>,<dst>' |
476 | * to save 3 bytes. | |
477 | */ | |
478 | if (imm32 == 0) { | |
479 | if (is_ereg(dst_reg)) | |
480 | EMIT1(add_2mod(0x40, dst_reg, dst_reg)); | |
481 | b2 = 0x31; /* xor */ | |
482 | b3 = 0xC0; | |
483 | EMIT2(b2, add_2reg(b3, dst_reg, dst_reg)); | |
484 | break; | |
485 | } | |
486 | ||
62258278 | 487 | /* mov %eax, imm32 */ |
e430f34e AS |
488 | if (is_ereg(dst_reg)) |
489 | EMIT1(add_1mod(0x40, dst_reg)); | |
490 | EMIT1_off32(add_1reg(0xB8, dst_reg), imm32); | |
62258278 AS |
491 | break; |
492 | ||
02ab695b | 493 | case BPF_LD | BPF_IMM | BPF_DW: |
606c88a8 DB |
494 | /* optimization: if imm64 is zero, use 'xor <dst>,<dst>' |
495 | * to save 7 bytes. | |
496 | */ | |
497 | if (insn[0].imm == 0 && insn[1].imm == 0) { | |
498 | b1 = add_2mod(0x48, dst_reg, dst_reg); | |
499 | b2 = 0x31; /* xor */ | |
500 | b3 = 0xC0; | |
501 | EMIT3(b1, b2, add_2reg(b3, dst_reg, dst_reg)); | |
502 | ||
503 | insn++; | |
504 | i++; | |
505 | break; | |
506 | } | |
507 | ||
02ab695b AS |
508 | /* movabsq %rax, imm64 */ |
509 | EMIT2(add_1mod(0x48, dst_reg), add_1reg(0xB8, dst_reg)); | |
510 | EMIT(insn[0].imm, 4); | |
511 | EMIT(insn[1].imm, 4); | |
512 | ||
513 | insn++; | |
514 | i++; | |
515 | break; | |
516 | ||
e430f34e | 517 | /* dst %= src, dst /= src, dst %= imm32, dst /= imm32 */ |
62258278 AS |
518 | case BPF_ALU | BPF_MOD | BPF_X: |
519 | case BPF_ALU | BPF_DIV | BPF_X: | |
520 | case BPF_ALU | BPF_MOD | BPF_K: | |
521 | case BPF_ALU | BPF_DIV | BPF_K: | |
522 | case BPF_ALU64 | BPF_MOD | BPF_X: | |
523 | case BPF_ALU64 | BPF_DIV | BPF_X: | |
524 | case BPF_ALU64 | BPF_MOD | BPF_K: | |
525 | case BPF_ALU64 | BPF_DIV | BPF_K: | |
526 | EMIT1(0x50); /* push rax */ | |
527 | EMIT1(0x52); /* push rdx */ | |
528 | ||
529 | if (BPF_SRC(insn->code) == BPF_X) | |
e430f34e AS |
530 | /* mov r11, src_reg */ |
531 | EMIT_mov(AUX_REG, src_reg); | |
62258278 | 532 | else |
e430f34e AS |
533 | /* mov r11, imm32 */ |
534 | EMIT3_off32(0x49, 0xC7, 0xC3, imm32); | |
62258278 | 535 | |
e430f34e AS |
536 | /* mov rax, dst_reg */ |
537 | EMIT_mov(BPF_REG_0, dst_reg); | |
62258278 AS |
538 | |
539 | /* xor edx, edx | |
540 | * equivalent to 'xor rdx, rdx', but one byte less | |
541 | */ | |
542 | EMIT2(0x31, 0xd2); | |
543 | ||
544 | if (BPF_SRC(insn->code) == BPF_X) { | |
e430f34e | 545 | /* if (src_reg == 0) return 0 */ |
62258278 AS |
546 | |
547 | /* cmp r11, 0 */ | |
548 | EMIT4(0x49, 0x83, 0xFB, 0x00); | |
549 | ||
550 | /* jne .+9 (skip over pop, pop, xor and jmp) */ | |
551 | EMIT2(X86_JNE, 1 + 1 + 2 + 5); | |
552 | EMIT1(0x5A); /* pop rdx */ | |
553 | EMIT1(0x58); /* pop rax */ | |
554 | EMIT2(0x31, 0xc0); /* xor eax, eax */ | |
555 | ||
556 | /* jmp cleanup_addr | |
557 | * addrs[i] - 11, because there are 11 bytes | |
558 | * after this insn: div, mov, pop, pop, mov | |
559 | */ | |
560 | jmp_offset = ctx->cleanup_addr - (addrs[i] - 11); | |
561 | EMIT1_off32(0xE9, jmp_offset); | |
562 | } | |
563 | ||
564 | if (BPF_CLASS(insn->code) == BPF_ALU64) | |
565 | /* div r11 */ | |
566 | EMIT3(0x49, 0xF7, 0xF3); | |
567 | else | |
568 | /* div r11d */ | |
569 | EMIT3(0x41, 0xF7, 0xF3); | |
570 | ||
571 | if (BPF_OP(insn->code) == BPF_MOD) | |
572 | /* mov r11, rdx */ | |
573 | EMIT3(0x49, 0x89, 0xD3); | |
574 | else | |
575 | /* mov r11, rax */ | |
576 | EMIT3(0x49, 0x89, 0xC3); | |
577 | ||
578 | EMIT1(0x5A); /* pop rdx */ | |
579 | EMIT1(0x58); /* pop rax */ | |
580 | ||
e430f34e AS |
581 | /* mov dst_reg, r11 */ |
582 | EMIT_mov(dst_reg, AUX_REG); | |
62258278 AS |
583 | break; |
584 | ||
585 | case BPF_ALU | BPF_MUL | BPF_K: | |
586 | case BPF_ALU | BPF_MUL | BPF_X: | |
587 | case BPF_ALU64 | BPF_MUL | BPF_K: | |
588 | case BPF_ALU64 | BPF_MUL | BPF_X: | |
589 | EMIT1(0x50); /* push rax */ | |
590 | EMIT1(0x52); /* push rdx */ | |
591 | ||
e430f34e AS |
592 | /* mov r11, dst_reg */ |
593 | EMIT_mov(AUX_REG, dst_reg); | |
62258278 AS |
594 | |
595 | if (BPF_SRC(insn->code) == BPF_X) | |
e430f34e AS |
596 | /* mov rax, src_reg */ |
597 | EMIT_mov(BPF_REG_0, src_reg); | |
62258278 | 598 | else |
e430f34e AS |
599 | /* mov rax, imm32 */ |
600 | EMIT3_off32(0x48, 0xC7, 0xC0, imm32); | |
62258278 AS |
601 | |
602 | if (BPF_CLASS(insn->code) == BPF_ALU64) | |
603 | EMIT1(add_1mod(0x48, AUX_REG)); | |
604 | else if (is_ereg(AUX_REG)) | |
605 | EMIT1(add_1mod(0x40, AUX_REG)); | |
606 | /* mul(q) r11 */ | |
607 | EMIT2(0xF7, add_1reg(0xE0, AUX_REG)); | |
608 | ||
609 | /* mov r11, rax */ | |
610 | EMIT_mov(AUX_REG, BPF_REG_0); | |
611 | ||
612 | EMIT1(0x5A); /* pop rdx */ | |
613 | EMIT1(0x58); /* pop rax */ | |
614 | ||
e430f34e AS |
615 | /* mov dst_reg, r11 */ |
616 | EMIT_mov(dst_reg, AUX_REG); | |
62258278 AS |
617 | break; |
618 | ||
619 | /* shifts */ | |
620 | case BPF_ALU | BPF_LSH | BPF_K: | |
621 | case BPF_ALU | BPF_RSH | BPF_K: | |
622 | case BPF_ALU | BPF_ARSH | BPF_K: | |
623 | case BPF_ALU64 | BPF_LSH | BPF_K: | |
624 | case BPF_ALU64 | BPF_RSH | BPF_K: | |
625 | case BPF_ALU64 | BPF_ARSH | BPF_K: | |
626 | if (BPF_CLASS(insn->code) == BPF_ALU64) | |
e430f34e AS |
627 | EMIT1(add_1mod(0x48, dst_reg)); |
628 | else if (is_ereg(dst_reg)) | |
629 | EMIT1(add_1mod(0x40, dst_reg)); | |
62258278 AS |
630 | |
631 | switch (BPF_OP(insn->code)) { | |
632 | case BPF_LSH: b3 = 0xE0; break; | |
633 | case BPF_RSH: b3 = 0xE8; break; | |
634 | case BPF_ARSH: b3 = 0xF8; break; | |
635 | } | |
e430f34e | 636 | EMIT3(0xC1, add_1reg(b3, dst_reg), imm32); |
62258278 AS |
637 | break; |
638 | ||
72b603ee AS |
639 | case BPF_ALU | BPF_LSH | BPF_X: |
640 | case BPF_ALU | BPF_RSH | BPF_X: | |
641 | case BPF_ALU | BPF_ARSH | BPF_X: | |
642 | case BPF_ALU64 | BPF_LSH | BPF_X: | |
643 | case BPF_ALU64 | BPF_RSH | BPF_X: | |
644 | case BPF_ALU64 | BPF_ARSH | BPF_X: | |
645 | ||
646 | /* check for bad case when dst_reg == rcx */ | |
647 | if (dst_reg == BPF_REG_4) { | |
648 | /* mov r11, dst_reg */ | |
649 | EMIT_mov(AUX_REG, dst_reg); | |
650 | dst_reg = AUX_REG; | |
651 | } | |
652 | ||
653 | if (src_reg != BPF_REG_4) { /* common case */ | |
654 | EMIT1(0x51); /* push rcx */ | |
655 | ||
656 | /* mov rcx, src_reg */ | |
657 | EMIT_mov(BPF_REG_4, src_reg); | |
658 | } | |
659 | ||
660 | /* shl %rax, %cl | shr %rax, %cl | sar %rax, %cl */ | |
661 | if (BPF_CLASS(insn->code) == BPF_ALU64) | |
662 | EMIT1(add_1mod(0x48, dst_reg)); | |
663 | else if (is_ereg(dst_reg)) | |
664 | EMIT1(add_1mod(0x40, dst_reg)); | |
665 | ||
666 | switch (BPF_OP(insn->code)) { | |
667 | case BPF_LSH: b3 = 0xE0; break; | |
668 | case BPF_RSH: b3 = 0xE8; break; | |
669 | case BPF_ARSH: b3 = 0xF8; break; | |
670 | } | |
671 | EMIT2(0xD3, add_1reg(b3, dst_reg)); | |
672 | ||
673 | if (src_reg != BPF_REG_4) | |
674 | EMIT1(0x59); /* pop rcx */ | |
675 | ||
676 | if (insn->dst_reg == BPF_REG_4) | |
677 | /* mov dst_reg, r11 */ | |
678 | EMIT_mov(insn->dst_reg, AUX_REG); | |
679 | break; | |
680 | ||
62258278 | 681 | case BPF_ALU | BPF_END | BPF_FROM_BE: |
e430f34e | 682 | switch (imm32) { |
62258278 AS |
683 | case 16: |
684 | /* emit 'ror %ax, 8' to swap lower 2 bytes */ | |
685 | EMIT1(0x66); | |
e430f34e | 686 | if (is_ereg(dst_reg)) |
62258278 | 687 | EMIT1(0x41); |
e430f34e | 688 | EMIT3(0xC1, add_1reg(0xC8, dst_reg), 8); |
343f845b AS |
689 | |
690 | /* emit 'movzwl eax, ax' */ | |
691 | if (is_ereg(dst_reg)) | |
692 | EMIT3(0x45, 0x0F, 0xB7); | |
693 | else | |
694 | EMIT2(0x0F, 0xB7); | |
695 | EMIT1(add_2reg(0xC0, dst_reg, dst_reg)); | |
62258278 AS |
696 | break; |
697 | case 32: | |
698 | /* emit 'bswap eax' to swap lower 4 bytes */ | |
e430f34e | 699 | if (is_ereg(dst_reg)) |
62258278 | 700 | EMIT2(0x41, 0x0F); |
0a14842f | 701 | else |
62258278 | 702 | EMIT1(0x0F); |
e430f34e | 703 | EMIT1(add_1reg(0xC8, dst_reg)); |
0a14842f | 704 | break; |
62258278 AS |
705 | case 64: |
706 | /* emit 'bswap rax' to swap 8 bytes */ | |
e430f34e AS |
707 | EMIT3(add_1mod(0x48, dst_reg), 0x0F, |
708 | add_1reg(0xC8, dst_reg)); | |
3b58908a ED |
709 | break; |
710 | } | |
62258278 AS |
711 | break; |
712 | ||
713 | case BPF_ALU | BPF_END | BPF_FROM_LE: | |
343f845b AS |
714 | switch (imm32) { |
715 | case 16: | |
716 | /* emit 'movzwl eax, ax' to zero extend 16-bit | |
717 | * into 64 bit | |
718 | */ | |
719 | if (is_ereg(dst_reg)) | |
720 | EMIT3(0x45, 0x0F, 0xB7); | |
721 | else | |
722 | EMIT2(0x0F, 0xB7); | |
723 | EMIT1(add_2reg(0xC0, dst_reg, dst_reg)); | |
724 | break; | |
725 | case 32: | |
726 | /* emit 'mov eax, eax' to clear upper 32-bits */ | |
727 | if (is_ereg(dst_reg)) | |
728 | EMIT1(0x45); | |
729 | EMIT2(0x89, add_2reg(0xC0, dst_reg, dst_reg)); | |
730 | break; | |
731 | case 64: | |
732 | /* nop */ | |
733 | break; | |
734 | } | |
62258278 AS |
735 | break; |
736 | ||
e430f34e | 737 | /* ST: *(u8*)(dst_reg + off) = imm */ |
62258278 | 738 | case BPF_ST | BPF_MEM | BPF_B: |
e430f34e | 739 | if (is_ereg(dst_reg)) |
62258278 AS |
740 | EMIT2(0x41, 0xC6); |
741 | else | |
742 | EMIT1(0xC6); | |
743 | goto st; | |
744 | case BPF_ST | BPF_MEM | BPF_H: | |
e430f34e | 745 | if (is_ereg(dst_reg)) |
62258278 AS |
746 | EMIT3(0x66, 0x41, 0xC7); |
747 | else | |
748 | EMIT2(0x66, 0xC7); | |
749 | goto st; | |
750 | case BPF_ST | BPF_MEM | BPF_W: | |
e430f34e | 751 | if (is_ereg(dst_reg)) |
62258278 AS |
752 | EMIT2(0x41, 0xC7); |
753 | else | |
754 | EMIT1(0xC7); | |
755 | goto st; | |
756 | case BPF_ST | BPF_MEM | BPF_DW: | |
e430f34e | 757 | EMIT2(add_1mod(0x48, dst_reg), 0xC7); |
62258278 AS |
758 | |
759 | st: if (is_imm8(insn->off)) | |
e430f34e | 760 | EMIT2(add_1reg(0x40, dst_reg), insn->off); |
62258278 | 761 | else |
e430f34e | 762 | EMIT1_off32(add_1reg(0x80, dst_reg), insn->off); |
62258278 | 763 | |
e430f34e | 764 | EMIT(imm32, bpf_size_to_x86_bytes(BPF_SIZE(insn->code))); |
62258278 AS |
765 | break; |
766 | ||
e430f34e | 767 | /* STX: *(u8*)(dst_reg + off) = src_reg */ |
62258278 AS |
768 | case BPF_STX | BPF_MEM | BPF_B: |
769 | /* emit 'mov byte ptr [rax + off], al' */ | |
e430f34e | 770 | if (is_ereg(dst_reg) || is_ereg(src_reg) || |
62258278 | 771 | /* have to add extra byte for x86 SIL, DIL regs */ |
e430f34e AS |
772 | src_reg == BPF_REG_1 || src_reg == BPF_REG_2) |
773 | EMIT2(add_2mod(0x40, dst_reg, src_reg), 0x88); | |
62258278 AS |
774 | else |
775 | EMIT1(0x88); | |
776 | goto stx; | |
777 | case BPF_STX | BPF_MEM | BPF_H: | |
e430f34e AS |
778 | if (is_ereg(dst_reg) || is_ereg(src_reg)) |
779 | EMIT3(0x66, add_2mod(0x40, dst_reg, src_reg), 0x89); | |
62258278 AS |
780 | else |
781 | EMIT2(0x66, 0x89); | |
782 | goto stx; | |
783 | case BPF_STX | BPF_MEM | BPF_W: | |
e430f34e AS |
784 | if (is_ereg(dst_reg) || is_ereg(src_reg)) |
785 | EMIT2(add_2mod(0x40, dst_reg, src_reg), 0x89); | |
62258278 AS |
786 | else |
787 | EMIT1(0x89); | |
788 | goto stx; | |
789 | case BPF_STX | BPF_MEM | BPF_DW: | |
e430f34e | 790 | EMIT2(add_2mod(0x48, dst_reg, src_reg), 0x89); |
62258278 | 791 | stx: if (is_imm8(insn->off)) |
e430f34e | 792 | EMIT2(add_2reg(0x40, dst_reg, src_reg), insn->off); |
62258278 | 793 | else |
e430f34e | 794 | EMIT1_off32(add_2reg(0x80, dst_reg, src_reg), |
62258278 AS |
795 | insn->off); |
796 | break; | |
797 | ||
e430f34e | 798 | /* LDX: dst_reg = *(u8*)(src_reg + off) */ |
62258278 AS |
799 | case BPF_LDX | BPF_MEM | BPF_B: |
800 | /* emit 'movzx rax, byte ptr [rax + off]' */ | |
e430f34e | 801 | EMIT3(add_2mod(0x48, src_reg, dst_reg), 0x0F, 0xB6); |
62258278 AS |
802 | goto ldx; |
803 | case BPF_LDX | BPF_MEM | BPF_H: | |
804 | /* emit 'movzx rax, word ptr [rax + off]' */ | |
e430f34e | 805 | EMIT3(add_2mod(0x48, src_reg, dst_reg), 0x0F, 0xB7); |
62258278 AS |
806 | goto ldx; |
807 | case BPF_LDX | BPF_MEM | BPF_W: | |
808 | /* emit 'mov eax, dword ptr [rax+0x14]' */ | |
e430f34e AS |
809 | if (is_ereg(dst_reg) || is_ereg(src_reg)) |
810 | EMIT2(add_2mod(0x40, src_reg, dst_reg), 0x8B); | |
62258278 AS |
811 | else |
812 | EMIT1(0x8B); | |
813 | goto ldx; | |
814 | case BPF_LDX | BPF_MEM | BPF_DW: | |
815 | /* emit 'mov rax, qword ptr [rax+0x14]' */ | |
e430f34e | 816 | EMIT2(add_2mod(0x48, src_reg, dst_reg), 0x8B); |
62258278 AS |
817 | ldx: /* if insn->off == 0 we can save one extra byte, but |
818 | * special case of x86 r13 which always needs an offset | |
819 | * is not worth the hassle | |
820 | */ | |
821 | if (is_imm8(insn->off)) | |
e430f34e | 822 | EMIT2(add_2reg(0x40, src_reg, dst_reg), insn->off); |
62258278 | 823 | else |
e430f34e | 824 | EMIT1_off32(add_2reg(0x80, src_reg, dst_reg), |
62258278 AS |
825 | insn->off); |
826 | break; | |
827 | ||
e430f34e | 828 | /* STX XADD: lock *(u32*)(dst_reg + off) += src_reg */ |
62258278 AS |
829 | case BPF_STX | BPF_XADD | BPF_W: |
830 | /* emit 'lock add dword ptr [rax + off], eax' */ | |
e430f34e AS |
831 | if (is_ereg(dst_reg) || is_ereg(src_reg)) |
832 | EMIT3(0xF0, add_2mod(0x40, dst_reg, src_reg), 0x01); | |
62258278 AS |
833 | else |
834 | EMIT2(0xF0, 0x01); | |
835 | goto xadd; | |
836 | case BPF_STX | BPF_XADD | BPF_DW: | |
e430f34e | 837 | EMIT3(0xF0, add_2mod(0x48, dst_reg, src_reg), 0x01); |
62258278 | 838 | xadd: if (is_imm8(insn->off)) |
e430f34e | 839 | EMIT2(add_2reg(0x40, dst_reg, src_reg), insn->off); |
62258278 | 840 | else |
e430f34e | 841 | EMIT1_off32(add_2reg(0x80, dst_reg, src_reg), |
62258278 AS |
842 | insn->off); |
843 | break; | |
844 | ||
845 | /* call */ | |
846 | case BPF_JMP | BPF_CALL: | |
e430f34e | 847 | func = (u8 *) __bpf_call_base + imm32; |
62258278 | 848 | jmp_offset = func - (image + addrs[i]); |
e0ee9c12 | 849 | if (seen_ld_abs) { |
17bedab2 | 850 | reload_skb_data = bpf_helper_changes_pkt_data(func); |
4e10df9a AS |
851 | if (reload_skb_data) { |
852 | EMIT1(0x57); /* push %rdi */ | |
853 | jmp_offset += 22; /* pop, mov, sub, mov */ | |
854 | } else { | |
855 | EMIT2(0x41, 0x52); /* push %r10 */ | |
856 | EMIT2(0x41, 0x51); /* push %r9 */ | |
857 | /* need to adjust jmp offset, since | |
858 | * pop %r9, pop %r10 take 4 bytes after call insn | |
859 | */ | |
860 | jmp_offset += 4; | |
861 | } | |
62258278 | 862 | } |
e430f34e | 863 | if (!imm32 || !is_simm32(jmp_offset)) { |
62258278 | 864 | pr_err("unsupported bpf func %d addr %p image %p\n", |
e430f34e | 865 | imm32, func, image); |
62258278 AS |
866 | return -EINVAL; |
867 | } | |
868 | EMIT1_off32(0xE8, jmp_offset); | |
e0ee9c12 | 869 | if (seen_ld_abs) { |
4e10df9a AS |
870 | if (reload_skb_data) { |
871 | EMIT1(0x5F); /* pop %rdi */ | |
872 | emit_load_skb_data_hlen(&prog); | |
873 | } else { | |
874 | EMIT2(0x41, 0x59); /* pop %r9 */ | |
875 | EMIT2(0x41, 0x5A); /* pop %r10 */ | |
876 | } | |
62258278 AS |
877 | } |
878 | break; | |
879 | ||
b52f00e6 AS |
880 | case BPF_JMP | BPF_CALL | BPF_X: |
881 | emit_bpf_tail_call(&prog); | |
882 | break; | |
883 | ||
62258278 AS |
884 | /* cond jump */ |
885 | case BPF_JMP | BPF_JEQ | BPF_X: | |
886 | case BPF_JMP | BPF_JNE | BPF_X: | |
887 | case BPF_JMP | BPF_JGT | BPF_X: | |
888 | case BPF_JMP | BPF_JGE | BPF_X: | |
889 | case BPF_JMP | BPF_JSGT | BPF_X: | |
890 | case BPF_JMP | BPF_JSGE | BPF_X: | |
e430f34e AS |
891 | /* cmp dst_reg, src_reg */ |
892 | EMIT3(add_2mod(0x48, dst_reg, src_reg), 0x39, | |
893 | add_2reg(0xC0, dst_reg, src_reg)); | |
62258278 AS |
894 | goto emit_cond_jmp; |
895 | ||
896 | case BPF_JMP | BPF_JSET | BPF_X: | |
e430f34e AS |
897 | /* test dst_reg, src_reg */ |
898 | EMIT3(add_2mod(0x48, dst_reg, src_reg), 0x85, | |
899 | add_2reg(0xC0, dst_reg, src_reg)); | |
62258278 AS |
900 | goto emit_cond_jmp; |
901 | ||
902 | case BPF_JMP | BPF_JSET | BPF_K: | |
e430f34e AS |
903 | /* test dst_reg, imm32 */ |
904 | EMIT1(add_1mod(0x48, dst_reg)); | |
905 | EMIT2_off32(0xF7, add_1reg(0xC0, dst_reg), imm32); | |
62258278 AS |
906 | goto emit_cond_jmp; |
907 | ||
908 | case BPF_JMP | BPF_JEQ | BPF_K: | |
909 | case BPF_JMP | BPF_JNE | BPF_K: | |
910 | case BPF_JMP | BPF_JGT | BPF_K: | |
911 | case BPF_JMP | BPF_JGE | BPF_K: | |
912 | case BPF_JMP | BPF_JSGT | BPF_K: | |
913 | case BPF_JMP | BPF_JSGE | BPF_K: | |
e430f34e AS |
914 | /* cmp dst_reg, imm8/32 */ |
915 | EMIT1(add_1mod(0x48, dst_reg)); | |
62258278 | 916 | |
e430f34e AS |
917 | if (is_imm8(imm32)) |
918 | EMIT3(0x83, add_1reg(0xF8, dst_reg), imm32); | |
62258278 | 919 | else |
e430f34e | 920 | EMIT2_off32(0x81, add_1reg(0xF8, dst_reg), imm32); |
62258278 AS |
921 | |
922 | emit_cond_jmp: /* convert BPF opcode to x86 */ | |
923 | switch (BPF_OP(insn->code)) { | |
924 | case BPF_JEQ: | |
925 | jmp_cond = X86_JE; | |
926 | break; | |
927 | case BPF_JSET: | |
928 | case BPF_JNE: | |
929 | jmp_cond = X86_JNE; | |
930 | break; | |
931 | case BPF_JGT: | |
932 | /* GT is unsigned '>', JA in x86 */ | |
933 | jmp_cond = X86_JA; | |
934 | break; | |
935 | case BPF_JGE: | |
936 | /* GE is unsigned '>=', JAE in x86 */ | |
937 | jmp_cond = X86_JAE; | |
938 | break; | |
939 | case BPF_JSGT: | |
940 | /* signed '>', GT in x86 */ | |
941 | jmp_cond = X86_JG; | |
942 | break; | |
943 | case BPF_JSGE: | |
944 | /* signed '>=', GE in x86 */ | |
945 | jmp_cond = X86_JGE; | |
946 | break; | |
947 | default: /* to silence gcc warning */ | |
948 | return -EFAULT; | |
949 | } | |
950 | jmp_offset = addrs[i + insn->off] - addrs[i]; | |
951 | if (is_imm8(jmp_offset)) { | |
952 | EMIT2(jmp_cond, jmp_offset); | |
953 | } else if (is_simm32(jmp_offset)) { | |
954 | EMIT2_off32(0x0F, jmp_cond + 0x10, jmp_offset); | |
955 | } else { | |
956 | pr_err("cond_jmp gen bug %llx\n", jmp_offset); | |
957 | return -EFAULT; | |
958 | } | |
959 | ||
960 | break; | |
0a14842f | 961 | |
62258278 AS |
962 | case BPF_JMP | BPF_JA: |
963 | jmp_offset = addrs[i + insn->off] - addrs[i]; | |
964 | if (!jmp_offset) | |
965 | /* optimize out nop jumps */ | |
966 | break; | |
967 | emit_jmp: | |
968 | if (is_imm8(jmp_offset)) { | |
969 | EMIT2(0xEB, jmp_offset); | |
970 | } else if (is_simm32(jmp_offset)) { | |
971 | EMIT1_off32(0xE9, jmp_offset); | |
972 | } else { | |
973 | pr_err("jmp gen bug %llx\n", jmp_offset); | |
974 | return -EFAULT; | |
975 | } | |
976 | break; | |
977 | ||
978 | case BPF_LD | BPF_IND | BPF_W: | |
979 | func = sk_load_word; | |
980 | goto common_load; | |
981 | case BPF_LD | BPF_ABS | BPF_W: | |
e430f34e | 982 | func = CHOOSE_LOAD_FUNC(imm32, sk_load_word); |
e0ee9c12 AS |
983 | common_load: |
984 | ctx->seen_ld_abs = seen_ld_abs = true; | |
62258278 AS |
985 | jmp_offset = func - (image + addrs[i]); |
986 | if (!func || !is_simm32(jmp_offset)) { | |
987 | pr_err("unsupported bpf func %d addr %p image %p\n", | |
e430f34e | 988 | imm32, func, image); |
62258278 AS |
989 | return -EINVAL; |
990 | } | |
991 | if (BPF_MODE(insn->code) == BPF_ABS) { | |
992 | /* mov %esi, imm32 */ | |
e430f34e | 993 | EMIT1_off32(0xBE, imm32); |
62258278 | 994 | } else { |
e430f34e AS |
995 | /* mov %rsi, src_reg */ |
996 | EMIT_mov(BPF_REG_2, src_reg); | |
997 | if (imm32) { | |
998 | if (is_imm8(imm32)) | |
62258278 | 999 | /* add %esi, imm8 */ |
e430f34e | 1000 | EMIT3(0x83, 0xC6, imm32); |
0a14842f | 1001 | else |
62258278 | 1002 | /* add %esi, imm32 */ |
e430f34e | 1003 | EMIT2_off32(0x81, 0xC6, imm32); |
0a14842f | 1004 | } |
62258278 AS |
1005 | } |
1006 | /* skb pointer is in R6 (%rbx), it will be copied into | |
1007 | * %rdi if skb_copy_bits() call is necessary. | |
1008 | * sk_load_* helpers also use %r10 and %r9d. | |
1009 | * See bpf_jit.S | |
1010 | */ | |
959a7579 DB |
1011 | if (seen_ax_reg) |
1012 | /* r10 = skb->data, mov %r10, off32(%rbx) */ | |
1013 | EMIT3_off32(0x4c, 0x8b, 0x93, | |
1014 | offsetof(struct sk_buff, data)); | |
62258278 AS |
1015 | EMIT1_off32(0xE8, jmp_offset); /* call */ |
1016 | break; | |
1017 | ||
1018 | case BPF_LD | BPF_IND | BPF_H: | |
1019 | func = sk_load_half; | |
1020 | goto common_load; | |
1021 | case BPF_LD | BPF_ABS | BPF_H: | |
e430f34e | 1022 | func = CHOOSE_LOAD_FUNC(imm32, sk_load_half); |
62258278 AS |
1023 | goto common_load; |
1024 | case BPF_LD | BPF_IND | BPF_B: | |
1025 | func = sk_load_byte; | |
1026 | goto common_load; | |
1027 | case BPF_LD | BPF_ABS | BPF_B: | |
e430f34e | 1028 | func = CHOOSE_LOAD_FUNC(imm32, sk_load_byte); |
62258278 AS |
1029 | goto common_load; |
1030 | ||
1031 | case BPF_JMP | BPF_EXIT: | |
769e0de6 | 1032 | if (seen_exit) { |
62258278 AS |
1033 | jmp_offset = ctx->cleanup_addr - addrs[i]; |
1034 | goto emit_jmp; | |
1035 | } | |
769e0de6 | 1036 | seen_exit = true; |
62258278 AS |
1037 | /* update cleanup_addr */ |
1038 | ctx->cleanup_addr = proglen; | |
1039 | /* mov rbx, qword ptr [rbp-X] */ | |
b52f00e6 | 1040 | EMIT3_off32(0x48, 0x8B, 0x9D, -STACKSIZE); |
62258278 | 1041 | /* mov r13, qword ptr [rbp-X] */ |
b52f00e6 | 1042 | EMIT3_off32(0x4C, 0x8B, 0xAD, -STACKSIZE + 8); |
62258278 | 1043 | /* mov r14, qword ptr [rbp-X] */ |
b52f00e6 | 1044 | EMIT3_off32(0x4C, 0x8B, 0xB5, -STACKSIZE + 16); |
62258278 | 1045 | /* mov r15, qword ptr [rbp-X] */ |
b52f00e6 | 1046 | EMIT3_off32(0x4C, 0x8B, 0xBD, -STACKSIZE + 24); |
62258278 AS |
1047 | |
1048 | EMIT1(0xC9); /* leave */ | |
1049 | EMIT1(0xC3); /* ret */ | |
1050 | break; | |
1051 | ||
f3c2af7b | 1052 | default: |
62258278 AS |
1053 | /* By design x64 JIT should support all BPF instructions |
1054 | * This error will be seen if new instruction was added | |
1055 | * to interpreter, but not to JIT | |
7ae457c1 | 1056 | * or if there is junk in bpf_prog |
62258278 AS |
1057 | */ |
1058 | pr_err("bpf_jit: unknown opcode %02x\n", insn->code); | |
f3c2af7b AS |
1059 | return -EINVAL; |
1060 | } | |
62258278 | 1061 | |
f3c2af7b | 1062 | ilen = prog - temp; |
e0ee9c12 | 1063 | if (ilen > BPF_MAX_INSN_SIZE) { |
9383191d | 1064 | pr_err("bpf_jit: fatal insn size error\n"); |
e0ee9c12 AS |
1065 | return -EFAULT; |
1066 | } | |
1067 | ||
f3c2af7b AS |
1068 | if (image) { |
1069 | if (unlikely(proglen + ilen > oldproglen)) { | |
9383191d | 1070 | pr_err("bpf_jit: fatal error\n"); |
f3c2af7b | 1071 | return -EFAULT; |
0a14842f | 1072 | } |
f3c2af7b | 1073 | memcpy(image + proglen, temp, ilen); |
0a14842f | 1074 | } |
f3c2af7b AS |
1075 | proglen += ilen; |
1076 | addrs[i] = proglen; | |
1077 | prog = temp; | |
1078 | } | |
f3c2af7b AS |
1079 | return proglen; |
1080 | } | |
1081 | ||
d1c55ab5 | 1082 | struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog) |
f3c2af7b AS |
1083 | { |
1084 | struct bpf_binary_header *header = NULL; | |
959a7579 | 1085 | struct bpf_prog *tmp, *orig_prog = prog; |
f3c2af7b AS |
1086 | int proglen, oldproglen = 0; |
1087 | struct jit_context ctx = {}; | |
959a7579 | 1088 | bool tmp_blinded = false; |
f3c2af7b AS |
1089 | u8 *image = NULL; |
1090 | int *addrs; | |
1091 | int pass; | |
1092 | int i; | |
1093 | ||
1094 | if (!bpf_jit_enable) | |
959a7579 DB |
1095 | return orig_prog; |
1096 | ||
1097 | tmp = bpf_jit_blind_constants(prog); | |
1098 | /* If blinding was requested and we failed during blinding, | |
1099 | * we must fall back to the interpreter. | |
1100 | */ | |
1101 | if (IS_ERR(tmp)) | |
1102 | return orig_prog; | |
1103 | if (tmp != prog) { | |
1104 | tmp_blinded = true; | |
1105 | prog = tmp; | |
1106 | } | |
0a14842f | 1107 | |
f3c2af7b | 1108 | addrs = kmalloc(prog->len * sizeof(*addrs), GFP_KERNEL); |
959a7579 DB |
1109 | if (!addrs) { |
1110 | prog = orig_prog; | |
1111 | goto out; | |
1112 | } | |
f3c2af7b AS |
1113 | |
1114 | /* Before first pass, make a rough estimation of addrs[] | |
1115 | * each bpf instruction is translated to less than 64 bytes | |
1116 | */ | |
1117 | for (proglen = 0, i = 0; i < prog->len; i++) { | |
1118 | proglen += 64; | |
1119 | addrs[i] = proglen; | |
1120 | } | |
1121 | ctx.cleanup_addr = proglen; | |
f3c2af7b | 1122 | |
3f7352bf AS |
1123 | /* JITed image shrinks with every pass and the loop iterates |
1124 | * until the image stops shrinking. Very large bpf programs | |
1125 | * may converge on the last pass. In such case do one more | |
1126 | * pass to emit the final image | |
1127 | */ | |
1128 | for (pass = 0; pass < 10 || image; pass++) { | |
f3c2af7b AS |
1129 | proglen = do_jit(prog, addrs, image, oldproglen, &ctx); |
1130 | if (proglen <= 0) { | |
1131 | image = NULL; | |
1132 | if (header) | |
738cbe72 | 1133 | bpf_jit_binary_free(header); |
959a7579 DB |
1134 | prog = orig_prog; |
1135 | goto out_addrs; | |
f3c2af7b | 1136 | } |
0a14842f | 1137 | if (image) { |
e0ee9c12 | 1138 | if (proglen != oldproglen) { |
f3c2af7b AS |
1139 | pr_err("bpf_jit: proglen=%d != oldproglen=%d\n", |
1140 | proglen, oldproglen); | |
959a7579 DB |
1141 | prog = orig_prog; |
1142 | goto out_addrs; | |
e0ee9c12 | 1143 | } |
0a14842f ED |
1144 | break; |
1145 | } | |
1146 | if (proglen == oldproglen) { | |
738cbe72 DB |
1147 | header = bpf_jit_binary_alloc(proglen, &image, |
1148 | 1, jit_fill_hole); | |
959a7579 DB |
1149 | if (!header) { |
1150 | prog = orig_prog; | |
1151 | goto out_addrs; | |
1152 | } | |
0a14842f ED |
1153 | } |
1154 | oldproglen = proglen; | |
1155 | } | |
79617801 | 1156 | |
0a14842f | 1157 | if (bpf_jit_enable > 1) |
485d6511 | 1158 | bpf_jit_dump(prog->len, proglen, pass + 1, image); |
0a14842f ED |
1159 | |
1160 | if (image) { | |
314beb9b | 1161 | bpf_flush_icache(header, image + proglen); |
9d876e79 | 1162 | bpf_jit_binary_lock_ro(header); |
f3c2af7b | 1163 | prog->bpf_func = (void *)image; |
a91263d5 | 1164 | prog->jited = 1; |
9d5ecb09 DB |
1165 | } else { |
1166 | prog = orig_prog; | |
0a14842f | 1167 | } |
959a7579 DB |
1168 | |
1169 | out_addrs: | |
0a14842f | 1170 | kfree(addrs); |
959a7579 DB |
1171 | out: |
1172 | if (tmp_blinded) | |
1173 | bpf_jit_prog_release_other(prog, prog == orig_prog ? | |
1174 | tmp : orig_prog); | |
d1c55ab5 | 1175 | return prog; |
0a14842f | 1176 | } |