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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 | /* |
19 | * assembly code in arch/x86/net/bpf_jit.S | |
20 | */ | |
62258278 | 21 | extern u8 sk_load_word[], sk_load_half[], sk_load_byte[]; |
a998d434 | 22 | extern u8 sk_load_word_positive_offset[], sk_load_half_positive_offset[]; |
62258278 | 23 | extern u8 sk_load_byte_positive_offset[]; |
a998d434 | 24 | extern u8 sk_load_word_negative_offset[], sk_load_half_negative_offset[]; |
62258278 | 25 | extern u8 sk_load_byte_negative_offset[]; |
0a14842f | 26 | |
5cccc702 | 27 | static u8 *emit_code(u8 *ptr, u32 bytes, unsigned int len) |
0a14842f ED |
28 | { |
29 | if (len == 1) | |
30 | *ptr = bytes; | |
31 | else if (len == 2) | |
32 | *(u16 *)ptr = bytes; | |
33 | else { | |
34 | *(u32 *)ptr = bytes; | |
35 | barrier(); | |
36 | } | |
37 | return ptr + len; | |
38 | } | |
39 | ||
b52f00e6 AS |
40 | #define EMIT(bytes, len) \ |
41 | do { prog = emit_code(prog, bytes, len); cnt += len; } while (0) | |
0a14842f ED |
42 | |
43 | #define EMIT1(b1) EMIT(b1, 1) | |
44 | #define EMIT2(b1, b2) EMIT((b1) + ((b2) << 8), 2) | |
45 | #define EMIT3(b1, b2, b3) EMIT((b1) + ((b2) << 8) + ((b3) << 16), 3) | |
46 | #define EMIT4(b1, b2, b3, b4) EMIT((b1) + ((b2) << 8) + ((b3) << 16) + ((b4) << 24), 4) | |
62258278 AS |
47 | #define EMIT1_off32(b1, off) \ |
48 | do {EMIT1(b1); EMIT(off, 4); } while (0) | |
49 | #define EMIT2_off32(b1, b2, off) \ | |
50 | do {EMIT2(b1, b2); EMIT(off, 4); } while (0) | |
51 | #define EMIT3_off32(b1, b2, b3, off) \ | |
52 | do {EMIT3(b1, b2, b3); EMIT(off, 4); } while (0) | |
53 | #define EMIT4_off32(b1, b2, b3, b4, off) \ | |
54 | do {EMIT4(b1, b2, b3, b4); EMIT(off, 4); } while (0) | |
0a14842f | 55 | |
5cccc702 | 56 | static bool is_imm8(int value) |
0a14842f ED |
57 | { |
58 | return value <= 127 && value >= -128; | |
59 | } | |
60 | ||
5cccc702 | 61 | static bool is_simm32(s64 value) |
0a14842f | 62 | { |
62258278 | 63 | return value == (s64) (s32) value; |
0a14842f ED |
64 | } |
65 | ||
e430f34e AS |
66 | /* mov dst, src */ |
67 | #define EMIT_mov(DST, SRC) \ | |
68 | do {if (DST != SRC) \ | |
69 | EMIT3(add_2mod(0x48, DST, SRC), 0x89, add_2reg(0xC0, DST, SRC)); \ | |
62258278 AS |
70 | } while (0) |
71 | ||
72 | static int bpf_size_to_x86_bytes(int bpf_size) | |
73 | { | |
74 | if (bpf_size == BPF_W) | |
75 | return 4; | |
76 | else if (bpf_size == BPF_H) | |
77 | return 2; | |
78 | else if (bpf_size == BPF_B) | |
79 | return 1; | |
80 | else if (bpf_size == BPF_DW) | |
81 | return 4; /* imm32 */ | |
82 | else | |
83 | return 0; | |
84 | } | |
0a14842f ED |
85 | |
86 | /* list of x86 cond jumps opcodes (. + s8) | |
87 | * Add 0x10 (and an extra 0x0f) to generate far jumps (. + s32) | |
88 | */ | |
89 | #define X86_JB 0x72 | |
90 | #define X86_JAE 0x73 | |
91 | #define X86_JE 0x74 | |
92 | #define X86_JNE 0x75 | |
93 | #define X86_JBE 0x76 | |
94 | #define X86_JA 0x77 | |
52afc51e | 95 | #define X86_JL 0x7C |
62258278 | 96 | #define X86_JGE 0x7D |
52afc51e | 97 | #define X86_JLE 0x7E |
62258278 | 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 | ||
de0a444d DB |
155 | static bool is_axreg(u32 reg) |
156 | { | |
157 | return reg == BPF_REG_0; | |
158 | } | |
159 | ||
62258278 | 160 | /* add modifiers if 'reg' maps to x64 registers r8..r15 */ |
5cccc702 | 161 | static u8 add_1mod(u8 byte, u32 reg) |
62258278 AS |
162 | { |
163 | if (is_ereg(reg)) | |
164 | byte |= 1; | |
165 | return byte; | |
166 | } | |
167 | ||
5cccc702 | 168 | static u8 add_2mod(u8 byte, u32 r1, u32 r2) |
62258278 AS |
169 | { |
170 | if (is_ereg(r1)) | |
171 | byte |= 1; | |
172 | if (is_ereg(r2)) | |
173 | byte |= 4; | |
174 | return byte; | |
175 | } | |
176 | ||
e430f34e | 177 | /* encode 'dst_reg' register into x64 opcode 'byte' */ |
5cccc702 | 178 | static u8 add_1reg(u8 byte, u32 dst_reg) |
62258278 | 179 | { |
e430f34e | 180 | return byte + reg2hex[dst_reg]; |
62258278 AS |
181 | } |
182 | ||
e430f34e | 183 | /* encode 'dst_reg' and 'src_reg' registers into x64 opcode 'byte' */ |
5cccc702 | 184 | static u8 add_2reg(u8 byte, u32 dst_reg, u32 src_reg) |
62258278 | 185 | { |
e430f34e | 186 | return byte + reg2hex[dst_reg] + (reg2hex[src_reg] << 3); |
62258278 AS |
187 | } |
188 | ||
738cbe72 DB |
189 | static void jit_fill_hole(void *area, unsigned int size) |
190 | { | |
191 | /* fill whole space with int3 instructions */ | |
192 | memset(area, 0xcc, size); | |
193 | } | |
194 | ||
f3c2af7b | 195 | struct jit_context { |
769e0de6 | 196 | int cleanup_addr; /* epilogue code offset */ |
62258278 | 197 | bool seen_ld_abs; |
959a7579 | 198 | bool seen_ax_reg; |
f3c2af7b AS |
199 | }; |
200 | ||
e0ee9c12 AS |
201 | /* maximum number of bytes emitted while JITing one eBPF insn */ |
202 | #define BPF_MAX_INSN_SIZE 128 | |
203 | #define BPF_INSN_SAFETY 64 | |
204 | ||
177366bf AS |
205 | #define AUX_STACK_SPACE \ |
206 | (32 /* space for rbx, r13, r14, r15 */ + \ | |
b52f00e6 AS |
207 | 8 /* space for skb_copy_bits() buffer */) |
208 | ||
177366bf | 209 | #define PROLOGUE_SIZE 37 |
b52f00e6 AS |
210 | |
211 | /* emit x64 prologue code for BPF program and check it's size. | |
212 | * bpf_tail_call helper will skip it while jumping into another program | |
213 | */ | |
2960ae48 | 214 | static void emit_prologue(u8 **pprog, u32 stack_depth) |
0a14842f | 215 | { |
b52f00e6 AS |
216 | u8 *prog = *pprog; |
217 | int cnt = 0; | |
0a14842f | 218 | |
62258278 AS |
219 | EMIT1(0x55); /* push rbp */ |
220 | EMIT3(0x48, 0x89, 0xE5); /* mov rbp,rsp */ | |
0a14842f | 221 | |
2960ae48 AS |
222 | /* sub rsp, rounded_stack_depth + AUX_STACK_SPACE */ |
223 | EMIT3_off32(0x48, 0x81, 0xEC, | |
224 | round_up(stack_depth, 8) + AUX_STACK_SPACE); | |
177366bf AS |
225 | |
226 | /* sub rbp, AUX_STACK_SPACE */ | |
227 | EMIT4(0x48, 0x83, 0xED, AUX_STACK_SPACE); | |
62258278 AS |
228 | |
229 | /* all classic BPF filters use R6(rbx) save it */ | |
230 | ||
177366bf AS |
231 | /* mov qword ptr [rbp+0],rbx */ |
232 | EMIT4(0x48, 0x89, 0x5D, 0); | |
62258278 | 233 | |
8fb575ca | 234 | /* bpf_convert_filter() maps classic BPF register X to R7 and uses R8 |
62258278 AS |
235 | * as temporary, so all tcpdump filters need to spill/fill R7(r13) and |
236 | * R8(r14). R9(r15) spill could be made conditional, but there is only | |
237 | * one 'bpf_error' return path out of helper functions inside bpf_jit.S | |
238 | * The overhead of extra spill is negligible for any filter other | |
239 | * than synthetic ones. Therefore not worth adding complexity. | |
240 | */ | |
241 | ||
177366bf AS |
242 | /* mov qword ptr [rbp+8],r13 */ |
243 | EMIT4(0x4C, 0x89, 0x6D, 8); | |
244 | /* mov qword ptr [rbp+16],r14 */ | |
245 | EMIT4(0x4C, 0x89, 0x75, 16); | |
246 | /* mov qword ptr [rbp+24],r15 */ | |
247 | EMIT4(0x4C, 0x89, 0x7D, 24); | |
62258278 | 248 | |
8b614aeb DB |
249 | /* Clear the tail call counter (tail_call_cnt): for eBPF tail calls |
250 | * we need to reset the counter to 0. It's done in two instructions, | |
251 | * resetting rax register to 0 (xor on eax gets 0 extended), and | |
252 | * moving it to the counter location. | |
253 | */ | |
62258278 | 254 | |
8b614aeb DB |
255 | /* xor eax, eax */ |
256 | EMIT2(0x31, 0xc0); | |
177366bf AS |
257 | /* mov qword ptr [rbp+32], rax */ |
258 | EMIT4(0x48, 0x89, 0x45, 32); | |
b52f00e6 AS |
259 | |
260 | BUILD_BUG_ON(cnt != PROLOGUE_SIZE); | |
261 | *pprog = prog; | |
262 | } | |
263 | ||
264 | /* generate the following code: | |
265 | * ... bpf_tail_call(void *ctx, struct bpf_array *array, u64 index) ... | |
266 | * if (index >= array->map.max_entries) | |
267 | * goto out; | |
268 | * if (++tail_call_cnt > MAX_TAIL_CALL_CNT) | |
269 | * goto out; | |
2a36f0b9 | 270 | * prog = array->ptrs[index]; |
b52f00e6 AS |
271 | * if (prog == NULL) |
272 | * goto out; | |
273 | * goto *(prog->bpf_func + prologue_size); | |
274 | * out: | |
275 | */ | |
276 | static void emit_bpf_tail_call(u8 **pprog) | |
277 | { | |
278 | u8 *prog = *pprog; | |
279 | int label1, label2, label3; | |
280 | int cnt = 0; | |
281 | ||
282 | /* rdi - pointer to ctx | |
283 | * rsi - pointer to bpf_array | |
284 | * rdx - index in bpf_array | |
285 | */ | |
286 | ||
287 | /* if (index >= array->map.max_entries) | |
288 | * goto out; | |
289 | */ | |
90caccdd AS |
290 | EMIT2(0x89, 0xD2); /* mov edx, edx */ |
291 | EMIT3(0x39, 0x56, /* cmp dword ptr [rsi + 16], edx */ | |
b52f00e6 | 292 | offsetof(struct bpf_array, map.max_entries)); |
84ccac6e | 293 | #define OFFSET1 43 /* number of bytes to jump */ |
b52f00e6 AS |
294 | EMIT2(X86_JBE, OFFSET1); /* jbe out */ |
295 | label1 = cnt; | |
296 | ||
297 | /* if (tail_call_cnt > MAX_TAIL_CALL_CNT) | |
298 | * goto out; | |
299 | */ | |
177366bf | 300 | EMIT2_off32(0x8B, 0x85, 36); /* mov eax, dword ptr [rbp + 36] */ |
b52f00e6 | 301 | EMIT3(0x83, 0xF8, MAX_TAIL_CALL_CNT); /* cmp eax, MAX_TAIL_CALL_CNT */ |
84ccac6e | 302 | #define OFFSET2 32 |
b52f00e6 AS |
303 | EMIT2(X86_JA, OFFSET2); /* ja out */ |
304 | label2 = cnt; | |
305 | EMIT3(0x83, 0xC0, 0x01); /* add eax, 1 */ | |
177366bf | 306 | EMIT2_off32(0x89, 0x85, 36); /* mov dword ptr [rbp + 36], eax */ |
b52f00e6 | 307 | |
2a36f0b9 | 308 | /* prog = array->ptrs[index]; */ |
84ccac6e | 309 | EMIT4_off32(0x48, 0x8B, 0x84, 0xD6, /* mov rax, [rsi + rdx * 8 + offsetof(...)] */ |
2a36f0b9 | 310 | offsetof(struct bpf_array, ptrs)); |
b52f00e6 AS |
311 | |
312 | /* if (prog == NULL) | |
313 | * goto out; | |
314 | */ | |
84ccac6e | 315 | EMIT3(0x48, 0x85, 0xC0); /* test rax,rax */ |
b52f00e6 AS |
316 | #define OFFSET3 10 |
317 | EMIT2(X86_JE, OFFSET3); /* je out */ | |
318 | label3 = cnt; | |
319 | ||
320 | /* goto *(prog->bpf_func + prologue_size); */ | |
321 | EMIT4(0x48, 0x8B, 0x40, /* mov rax, qword ptr [rax + 32] */ | |
322 | offsetof(struct bpf_prog, bpf_func)); | |
323 | EMIT4(0x48, 0x83, 0xC0, PROLOGUE_SIZE); /* add rax, prologue_size */ | |
324 | ||
325 | /* now we're ready to jump into next BPF program | |
326 | * rdi == ctx (1st arg) | |
327 | * rax == prog->bpf_func + prologue_size | |
328 | */ | |
329 | EMIT2(0xFF, 0xE0); /* jmp rax */ | |
330 | ||
331 | /* out: */ | |
332 | BUILD_BUG_ON(cnt - label1 != OFFSET1); | |
333 | BUILD_BUG_ON(cnt - label2 != OFFSET2); | |
334 | BUILD_BUG_ON(cnt - label3 != OFFSET3); | |
335 | *pprog = prog; | |
336 | } | |
337 | ||
4e10df9a AS |
338 | |
339 | static void emit_load_skb_data_hlen(u8 **pprog) | |
340 | { | |
341 | u8 *prog = *pprog; | |
342 | int cnt = 0; | |
343 | ||
344 | /* r9d = skb->len - skb->data_len (headlen) | |
345 | * r10 = skb->data | |
346 | */ | |
347 | /* mov %r9d, off32(%rdi) */ | |
348 | EMIT3_off32(0x44, 0x8b, 0x8f, offsetof(struct sk_buff, len)); | |
349 | ||
350 | /* sub %r9d, off32(%rdi) */ | |
351 | EMIT3_off32(0x44, 0x2b, 0x8f, offsetof(struct sk_buff, data_len)); | |
352 | ||
353 | /* mov %r10, off32(%rdi) */ | |
354 | EMIT3_off32(0x4c, 0x8b, 0x97, offsetof(struct sk_buff, data)); | |
355 | *pprog = prog; | |
356 | } | |
357 | ||
b52f00e6 AS |
358 | static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image, |
359 | int oldproglen, struct jit_context *ctx) | |
360 | { | |
361 | struct bpf_insn *insn = bpf_prog->insnsi; | |
362 | int insn_cnt = bpf_prog->len; | |
363 | bool seen_ld_abs = ctx->seen_ld_abs | (oldproglen == 0); | |
959a7579 | 364 | bool seen_ax_reg = ctx->seen_ax_reg | (oldproglen == 0); |
b52f00e6 AS |
365 | bool seen_exit = false; |
366 | u8 temp[BPF_MAX_INSN_SIZE + BPF_INSN_SAFETY]; | |
367 | int i, cnt = 0; | |
368 | int proglen = 0; | |
369 | u8 *prog = temp; | |
370 | ||
2960ae48 | 371 | emit_prologue(&prog, bpf_prog->aux->stack_depth); |
b52f00e6 | 372 | |
4e10df9a AS |
373 | if (seen_ld_abs) |
374 | emit_load_skb_data_hlen(&prog); | |
62258278 AS |
375 | |
376 | for (i = 0; i < insn_cnt; i++, insn++) { | |
e430f34e AS |
377 | const s32 imm32 = insn->imm; |
378 | u32 dst_reg = insn->dst_reg; | |
379 | u32 src_reg = insn->src_reg; | |
62258278 AS |
380 | u8 b1 = 0, b2 = 0, b3 = 0; |
381 | s64 jmp_offset; | |
382 | u8 jmp_cond; | |
4e10df9a | 383 | bool reload_skb_data; |
62258278 AS |
384 | int ilen; |
385 | u8 *func; | |
386 | ||
959a7579 DB |
387 | if (dst_reg == BPF_REG_AX || src_reg == BPF_REG_AX) |
388 | ctx->seen_ax_reg = seen_ax_reg = true; | |
389 | ||
62258278 AS |
390 | switch (insn->code) { |
391 | /* ALU */ | |
392 | case BPF_ALU | BPF_ADD | BPF_X: | |
393 | case BPF_ALU | BPF_SUB | BPF_X: | |
394 | case BPF_ALU | BPF_AND | BPF_X: | |
395 | case BPF_ALU | BPF_OR | BPF_X: | |
396 | case BPF_ALU | BPF_XOR | BPF_X: | |
397 | case BPF_ALU64 | BPF_ADD | BPF_X: | |
398 | case BPF_ALU64 | BPF_SUB | BPF_X: | |
399 | case BPF_ALU64 | BPF_AND | BPF_X: | |
400 | case BPF_ALU64 | BPF_OR | BPF_X: | |
401 | case BPF_ALU64 | BPF_XOR | BPF_X: | |
402 | switch (BPF_OP(insn->code)) { | |
403 | case BPF_ADD: b2 = 0x01; break; | |
404 | case BPF_SUB: b2 = 0x29; break; | |
405 | case BPF_AND: b2 = 0x21; break; | |
406 | case BPF_OR: b2 = 0x09; break; | |
407 | case BPF_XOR: b2 = 0x31; break; | |
0a14842f | 408 | } |
62258278 | 409 | if (BPF_CLASS(insn->code) == BPF_ALU64) |
e430f34e AS |
410 | EMIT1(add_2mod(0x48, dst_reg, src_reg)); |
411 | else if (is_ereg(dst_reg) || is_ereg(src_reg)) | |
412 | EMIT1(add_2mod(0x40, dst_reg, src_reg)); | |
413 | EMIT2(b2, add_2reg(0xC0, dst_reg, src_reg)); | |
62258278 | 414 | break; |
0a14842f | 415 | |
e430f34e | 416 | /* mov dst, src */ |
62258278 | 417 | case BPF_ALU64 | BPF_MOV | BPF_X: |
e430f34e | 418 | EMIT_mov(dst_reg, src_reg); |
0a14842f | 419 | break; |
0a14842f | 420 | |
e430f34e | 421 | /* mov32 dst, src */ |
62258278 | 422 | case BPF_ALU | BPF_MOV | BPF_X: |
e430f34e AS |
423 | if (is_ereg(dst_reg) || is_ereg(src_reg)) |
424 | EMIT1(add_2mod(0x40, dst_reg, src_reg)); | |
425 | EMIT2(0x89, add_2reg(0xC0, dst_reg, src_reg)); | |
62258278 | 426 | break; |
0a14842f | 427 | |
e430f34e | 428 | /* neg dst */ |
62258278 AS |
429 | case BPF_ALU | BPF_NEG: |
430 | case BPF_ALU64 | BPF_NEG: | |
431 | if (BPF_CLASS(insn->code) == BPF_ALU64) | |
e430f34e AS |
432 | EMIT1(add_1mod(0x48, dst_reg)); |
433 | else if (is_ereg(dst_reg)) | |
434 | EMIT1(add_1mod(0x40, dst_reg)); | |
435 | EMIT2(0xF7, add_1reg(0xD8, dst_reg)); | |
62258278 AS |
436 | break; |
437 | ||
438 | case BPF_ALU | BPF_ADD | BPF_K: | |
439 | case BPF_ALU | BPF_SUB | BPF_K: | |
440 | case BPF_ALU | BPF_AND | BPF_K: | |
441 | case BPF_ALU | BPF_OR | BPF_K: | |
442 | case BPF_ALU | BPF_XOR | BPF_K: | |
443 | case BPF_ALU64 | BPF_ADD | BPF_K: | |
444 | case BPF_ALU64 | BPF_SUB | BPF_K: | |
445 | case BPF_ALU64 | BPF_AND | BPF_K: | |
446 | case BPF_ALU64 | BPF_OR | BPF_K: | |
447 | case BPF_ALU64 | BPF_XOR | BPF_K: | |
448 | if (BPF_CLASS(insn->code) == BPF_ALU64) | |
e430f34e AS |
449 | EMIT1(add_1mod(0x48, dst_reg)); |
450 | else if (is_ereg(dst_reg)) | |
451 | EMIT1(add_1mod(0x40, dst_reg)); | |
62258278 | 452 | |
de0a444d DB |
453 | /* b3 holds 'normal' opcode, b2 short form only valid |
454 | * in case dst is eax/rax. | |
455 | */ | |
62258278 | 456 | switch (BPF_OP(insn->code)) { |
de0a444d DB |
457 | case BPF_ADD: |
458 | b3 = 0xC0; | |
459 | b2 = 0x05; | |
460 | break; | |
461 | case BPF_SUB: | |
462 | b3 = 0xE8; | |
463 | b2 = 0x2D; | |
464 | break; | |
465 | case BPF_AND: | |
466 | b3 = 0xE0; | |
467 | b2 = 0x25; | |
468 | break; | |
469 | case BPF_OR: | |
470 | b3 = 0xC8; | |
471 | b2 = 0x0D; | |
472 | break; | |
473 | case BPF_XOR: | |
474 | b3 = 0xF0; | |
475 | b2 = 0x35; | |
476 | break; | |
62258278 AS |
477 | } |
478 | ||
e430f34e AS |
479 | if (is_imm8(imm32)) |
480 | EMIT3(0x83, add_1reg(b3, dst_reg), imm32); | |
de0a444d DB |
481 | else if (is_axreg(dst_reg)) |
482 | EMIT1_off32(b2, imm32); | |
62258278 | 483 | else |
e430f34e | 484 | EMIT2_off32(0x81, add_1reg(b3, dst_reg), imm32); |
62258278 AS |
485 | break; |
486 | ||
487 | case BPF_ALU64 | BPF_MOV | BPF_K: | |
488 | /* optimization: if imm32 is positive, | |
489 | * use 'mov eax, imm32' (which zero-extends imm32) | |
490 | * to save 2 bytes | |
491 | */ | |
e430f34e | 492 | if (imm32 < 0) { |
62258278 | 493 | /* 'mov rax, imm32' sign extends imm32 */ |
e430f34e | 494 | b1 = add_1mod(0x48, dst_reg); |
62258278 AS |
495 | b2 = 0xC7; |
496 | b3 = 0xC0; | |
e430f34e | 497 | EMIT3_off32(b1, b2, add_1reg(b3, dst_reg), imm32); |
0a14842f | 498 | break; |
62258278 AS |
499 | } |
500 | ||
501 | case BPF_ALU | BPF_MOV | BPF_K: | |
606c88a8 DB |
502 | /* optimization: if imm32 is zero, use 'xor <dst>,<dst>' |
503 | * to save 3 bytes. | |
504 | */ | |
505 | if (imm32 == 0) { | |
506 | if (is_ereg(dst_reg)) | |
507 | EMIT1(add_2mod(0x40, dst_reg, dst_reg)); | |
508 | b2 = 0x31; /* xor */ | |
509 | b3 = 0xC0; | |
510 | EMIT2(b2, add_2reg(b3, dst_reg, dst_reg)); | |
511 | break; | |
512 | } | |
513 | ||
62258278 | 514 | /* mov %eax, imm32 */ |
e430f34e AS |
515 | if (is_ereg(dst_reg)) |
516 | EMIT1(add_1mod(0x40, dst_reg)); | |
517 | EMIT1_off32(add_1reg(0xB8, dst_reg), imm32); | |
62258278 AS |
518 | break; |
519 | ||
02ab695b | 520 | case BPF_LD | BPF_IMM | BPF_DW: |
606c88a8 DB |
521 | /* optimization: if imm64 is zero, use 'xor <dst>,<dst>' |
522 | * to save 7 bytes. | |
523 | */ | |
524 | if (insn[0].imm == 0 && insn[1].imm == 0) { | |
525 | b1 = add_2mod(0x48, dst_reg, dst_reg); | |
526 | b2 = 0x31; /* xor */ | |
527 | b3 = 0xC0; | |
528 | EMIT3(b1, b2, add_2reg(b3, dst_reg, dst_reg)); | |
529 | ||
530 | insn++; | |
531 | i++; | |
532 | break; | |
533 | } | |
534 | ||
02ab695b AS |
535 | /* movabsq %rax, imm64 */ |
536 | EMIT2(add_1mod(0x48, dst_reg), add_1reg(0xB8, dst_reg)); | |
537 | EMIT(insn[0].imm, 4); | |
538 | EMIT(insn[1].imm, 4); | |
539 | ||
540 | insn++; | |
541 | i++; | |
542 | break; | |
543 | ||
e430f34e | 544 | /* dst %= src, dst /= src, dst %= imm32, dst /= imm32 */ |
62258278 AS |
545 | case BPF_ALU | BPF_MOD | BPF_X: |
546 | case BPF_ALU | BPF_DIV | BPF_X: | |
547 | case BPF_ALU | BPF_MOD | BPF_K: | |
548 | case BPF_ALU | BPF_DIV | BPF_K: | |
549 | case BPF_ALU64 | BPF_MOD | BPF_X: | |
550 | case BPF_ALU64 | BPF_DIV | BPF_X: | |
551 | case BPF_ALU64 | BPF_MOD | BPF_K: | |
552 | case BPF_ALU64 | BPF_DIV | BPF_K: | |
553 | EMIT1(0x50); /* push rax */ | |
554 | EMIT1(0x52); /* push rdx */ | |
555 | ||
556 | if (BPF_SRC(insn->code) == BPF_X) | |
e430f34e AS |
557 | /* mov r11, src_reg */ |
558 | EMIT_mov(AUX_REG, src_reg); | |
62258278 | 559 | else |
e430f34e AS |
560 | /* mov r11, imm32 */ |
561 | EMIT3_off32(0x49, 0xC7, 0xC3, imm32); | |
62258278 | 562 | |
e430f34e AS |
563 | /* mov rax, dst_reg */ |
564 | EMIT_mov(BPF_REG_0, dst_reg); | |
62258278 AS |
565 | |
566 | /* xor edx, edx | |
567 | * equivalent to 'xor rdx, rdx', but one byte less | |
568 | */ | |
569 | EMIT2(0x31, 0xd2); | |
570 | ||
62258278 AS |
571 | if (BPF_CLASS(insn->code) == BPF_ALU64) |
572 | /* div r11 */ | |
573 | EMIT3(0x49, 0xF7, 0xF3); | |
574 | else | |
575 | /* div r11d */ | |
576 | EMIT3(0x41, 0xF7, 0xF3); | |
577 | ||
578 | if (BPF_OP(insn->code) == BPF_MOD) | |
579 | /* mov r11, rdx */ | |
580 | EMIT3(0x49, 0x89, 0xD3); | |
581 | else | |
582 | /* mov r11, rax */ | |
583 | EMIT3(0x49, 0x89, 0xC3); | |
584 | ||
585 | EMIT1(0x5A); /* pop rdx */ | |
586 | EMIT1(0x58); /* pop rax */ | |
587 | ||
e430f34e AS |
588 | /* mov dst_reg, r11 */ |
589 | EMIT_mov(dst_reg, AUX_REG); | |
62258278 AS |
590 | break; |
591 | ||
592 | case BPF_ALU | BPF_MUL | BPF_K: | |
593 | case BPF_ALU | BPF_MUL | BPF_X: | |
594 | case BPF_ALU64 | BPF_MUL | BPF_K: | |
595 | case BPF_ALU64 | BPF_MUL | BPF_X: | |
596 | EMIT1(0x50); /* push rax */ | |
597 | EMIT1(0x52); /* push rdx */ | |
598 | ||
e430f34e AS |
599 | /* mov r11, dst_reg */ |
600 | EMIT_mov(AUX_REG, dst_reg); | |
62258278 AS |
601 | |
602 | if (BPF_SRC(insn->code) == BPF_X) | |
e430f34e AS |
603 | /* mov rax, src_reg */ |
604 | EMIT_mov(BPF_REG_0, src_reg); | |
62258278 | 605 | else |
e430f34e AS |
606 | /* mov rax, imm32 */ |
607 | EMIT3_off32(0x48, 0xC7, 0xC0, imm32); | |
62258278 AS |
608 | |
609 | if (BPF_CLASS(insn->code) == BPF_ALU64) | |
610 | EMIT1(add_1mod(0x48, AUX_REG)); | |
611 | else if (is_ereg(AUX_REG)) | |
612 | EMIT1(add_1mod(0x40, AUX_REG)); | |
613 | /* mul(q) r11 */ | |
614 | EMIT2(0xF7, add_1reg(0xE0, AUX_REG)); | |
615 | ||
616 | /* mov r11, rax */ | |
617 | EMIT_mov(AUX_REG, BPF_REG_0); | |
618 | ||
619 | EMIT1(0x5A); /* pop rdx */ | |
620 | EMIT1(0x58); /* pop rax */ | |
621 | ||
e430f34e AS |
622 | /* mov dst_reg, r11 */ |
623 | EMIT_mov(dst_reg, AUX_REG); | |
62258278 AS |
624 | break; |
625 | ||
626 | /* shifts */ | |
627 | case BPF_ALU | BPF_LSH | BPF_K: | |
628 | case BPF_ALU | BPF_RSH | BPF_K: | |
629 | case BPF_ALU | BPF_ARSH | BPF_K: | |
630 | case BPF_ALU64 | BPF_LSH | BPF_K: | |
631 | case BPF_ALU64 | BPF_RSH | BPF_K: | |
632 | case BPF_ALU64 | BPF_ARSH | BPF_K: | |
633 | if (BPF_CLASS(insn->code) == BPF_ALU64) | |
e430f34e AS |
634 | EMIT1(add_1mod(0x48, dst_reg)); |
635 | else if (is_ereg(dst_reg)) | |
636 | EMIT1(add_1mod(0x40, dst_reg)); | |
62258278 AS |
637 | |
638 | switch (BPF_OP(insn->code)) { | |
639 | case BPF_LSH: b3 = 0xE0; break; | |
640 | case BPF_RSH: b3 = 0xE8; break; | |
641 | case BPF_ARSH: b3 = 0xF8; break; | |
642 | } | |
88e69a1f DB |
643 | |
644 | if (imm32 == 1) | |
645 | EMIT2(0xD1, add_1reg(b3, dst_reg)); | |
646 | else | |
647 | EMIT3(0xC1, add_1reg(b3, dst_reg), imm32); | |
62258278 AS |
648 | break; |
649 | ||
72b603ee AS |
650 | case BPF_ALU | BPF_LSH | BPF_X: |
651 | case BPF_ALU | BPF_RSH | BPF_X: | |
652 | case BPF_ALU | BPF_ARSH | BPF_X: | |
653 | case BPF_ALU64 | BPF_LSH | BPF_X: | |
654 | case BPF_ALU64 | BPF_RSH | BPF_X: | |
655 | case BPF_ALU64 | BPF_ARSH | BPF_X: | |
656 | ||
657 | /* check for bad case when dst_reg == rcx */ | |
658 | if (dst_reg == BPF_REG_4) { | |
659 | /* mov r11, dst_reg */ | |
660 | EMIT_mov(AUX_REG, dst_reg); | |
661 | dst_reg = AUX_REG; | |
662 | } | |
663 | ||
664 | if (src_reg != BPF_REG_4) { /* common case */ | |
665 | EMIT1(0x51); /* push rcx */ | |
666 | ||
667 | /* mov rcx, src_reg */ | |
668 | EMIT_mov(BPF_REG_4, src_reg); | |
669 | } | |
670 | ||
671 | /* shl %rax, %cl | shr %rax, %cl | sar %rax, %cl */ | |
672 | if (BPF_CLASS(insn->code) == BPF_ALU64) | |
673 | EMIT1(add_1mod(0x48, dst_reg)); | |
674 | else if (is_ereg(dst_reg)) | |
675 | EMIT1(add_1mod(0x40, dst_reg)); | |
676 | ||
677 | switch (BPF_OP(insn->code)) { | |
678 | case BPF_LSH: b3 = 0xE0; break; | |
679 | case BPF_RSH: b3 = 0xE8; break; | |
680 | case BPF_ARSH: b3 = 0xF8; break; | |
681 | } | |
682 | EMIT2(0xD3, add_1reg(b3, dst_reg)); | |
683 | ||
684 | if (src_reg != BPF_REG_4) | |
685 | EMIT1(0x59); /* pop rcx */ | |
686 | ||
687 | if (insn->dst_reg == BPF_REG_4) | |
688 | /* mov dst_reg, r11 */ | |
689 | EMIT_mov(insn->dst_reg, AUX_REG); | |
690 | break; | |
691 | ||
62258278 | 692 | case BPF_ALU | BPF_END | BPF_FROM_BE: |
e430f34e | 693 | switch (imm32) { |
62258278 AS |
694 | case 16: |
695 | /* emit 'ror %ax, 8' to swap lower 2 bytes */ | |
696 | EMIT1(0x66); | |
e430f34e | 697 | if (is_ereg(dst_reg)) |
62258278 | 698 | EMIT1(0x41); |
e430f34e | 699 | EMIT3(0xC1, add_1reg(0xC8, dst_reg), 8); |
343f845b AS |
700 | |
701 | /* emit 'movzwl eax, ax' */ | |
702 | if (is_ereg(dst_reg)) | |
703 | EMIT3(0x45, 0x0F, 0xB7); | |
704 | else | |
705 | EMIT2(0x0F, 0xB7); | |
706 | EMIT1(add_2reg(0xC0, dst_reg, dst_reg)); | |
62258278 AS |
707 | break; |
708 | case 32: | |
709 | /* emit 'bswap eax' to swap lower 4 bytes */ | |
e430f34e | 710 | if (is_ereg(dst_reg)) |
62258278 | 711 | EMIT2(0x41, 0x0F); |
0a14842f | 712 | else |
62258278 | 713 | EMIT1(0x0F); |
e430f34e | 714 | EMIT1(add_1reg(0xC8, dst_reg)); |
0a14842f | 715 | break; |
62258278 AS |
716 | case 64: |
717 | /* emit 'bswap rax' to swap 8 bytes */ | |
e430f34e AS |
718 | EMIT3(add_1mod(0x48, dst_reg), 0x0F, |
719 | add_1reg(0xC8, dst_reg)); | |
3b58908a ED |
720 | break; |
721 | } | |
62258278 AS |
722 | break; |
723 | ||
724 | case BPF_ALU | BPF_END | BPF_FROM_LE: | |
343f845b AS |
725 | switch (imm32) { |
726 | case 16: | |
727 | /* emit 'movzwl eax, ax' to zero extend 16-bit | |
728 | * into 64 bit | |
729 | */ | |
730 | if (is_ereg(dst_reg)) | |
731 | EMIT3(0x45, 0x0F, 0xB7); | |
732 | else | |
733 | EMIT2(0x0F, 0xB7); | |
734 | EMIT1(add_2reg(0xC0, dst_reg, dst_reg)); | |
735 | break; | |
736 | case 32: | |
737 | /* emit 'mov eax, eax' to clear upper 32-bits */ | |
738 | if (is_ereg(dst_reg)) | |
739 | EMIT1(0x45); | |
740 | EMIT2(0x89, add_2reg(0xC0, dst_reg, dst_reg)); | |
741 | break; | |
742 | case 64: | |
743 | /* nop */ | |
744 | break; | |
745 | } | |
62258278 AS |
746 | break; |
747 | ||
e430f34e | 748 | /* ST: *(u8*)(dst_reg + off) = imm */ |
62258278 | 749 | case BPF_ST | BPF_MEM | BPF_B: |
e430f34e | 750 | if (is_ereg(dst_reg)) |
62258278 AS |
751 | EMIT2(0x41, 0xC6); |
752 | else | |
753 | EMIT1(0xC6); | |
754 | goto st; | |
755 | case BPF_ST | BPF_MEM | BPF_H: | |
e430f34e | 756 | if (is_ereg(dst_reg)) |
62258278 AS |
757 | EMIT3(0x66, 0x41, 0xC7); |
758 | else | |
759 | EMIT2(0x66, 0xC7); | |
760 | goto st; | |
761 | case BPF_ST | BPF_MEM | BPF_W: | |
e430f34e | 762 | if (is_ereg(dst_reg)) |
62258278 AS |
763 | EMIT2(0x41, 0xC7); |
764 | else | |
765 | EMIT1(0xC7); | |
766 | goto st; | |
767 | case BPF_ST | BPF_MEM | BPF_DW: | |
e430f34e | 768 | EMIT2(add_1mod(0x48, dst_reg), 0xC7); |
62258278 AS |
769 | |
770 | st: if (is_imm8(insn->off)) | |
e430f34e | 771 | EMIT2(add_1reg(0x40, dst_reg), insn->off); |
62258278 | 772 | else |
e430f34e | 773 | EMIT1_off32(add_1reg(0x80, dst_reg), insn->off); |
62258278 | 774 | |
e430f34e | 775 | EMIT(imm32, bpf_size_to_x86_bytes(BPF_SIZE(insn->code))); |
62258278 AS |
776 | break; |
777 | ||
e430f34e | 778 | /* STX: *(u8*)(dst_reg + off) = src_reg */ |
62258278 AS |
779 | case BPF_STX | BPF_MEM | BPF_B: |
780 | /* emit 'mov byte ptr [rax + off], al' */ | |
e430f34e | 781 | if (is_ereg(dst_reg) || is_ereg(src_reg) || |
62258278 | 782 | /* have to add extra byte for x86 SIL, DIL regs */ |
e430f34e AS |
783 | src_reg == BPF_REG_1 || src_reg == BPF_REG_2) |
784 | EMIT2(add_2mod(0x40, dst_reg, src_reg), 0x88); | |
62258278 AS |
785 | else |
786 | EMIT1(0x88); | |
787 | goto stx; | |
788 | case BPF_STX | BPF_MEM | BPF_H: | |
e430f34e AS |
789 | if (is_ereg(dst_reg) || is_ereg(src_reg)) |
790 | EMIT3(0x66, add_2mod(0x40, dst_reg, src_reg), 0x89); | |
62258278 AS |
791 | else |
792 | EMIT2(0x66, 0x89); | |
793 | goto stx; | |
794 | case BPF_STX | BPF_MEM | BPF_W: | |
e430f34e AS |
795 | if (is_ereg(dst_reg) || is_ereg(src_reg)) |
796 | EMIT2(add_2mod(0x40, dst_reg, src_reg), 0x89); | |
62258278 AS |
797 | else |
798 | EMIT1(0x89); | |
799 | goto stx; | |
800 | case BPF_STX | BPF_MEM | BPF_DW: | |
e430f34e | 801 | EMIT2(add_2mod(0x48, dst_reg, src_reg), 0x89); |
62258278 | 802 | stx: if (is_imm8(insn->off)) |
e430f34e | 803 | EMIT2(add_2reg(0x40, dst_reg, src_reg), insn->off); |
62258278 | 804 | else |
e430f34e | 805 | EMIT1_off32(add_2reg(0x80, dst_reg, src_reg), |
62258278 AS |
806 | insn->off); |
807 | break; | |
808 | ||
e430f34e | 809 | /* LDX: dst_reg = *(u8*)(src_reg + off) */ |
62258278 AS |
810 | case BPF_LDX | BPF_MEM | BPF_B: |
811 | /* emit 'movzx rax, byte ptr [rax + off]' */ | |
e430f34e | 812 | EMIT3(add_2mod(0x48, src_reg, dst_reg), 0x0F, 0xB6); |
62258278 AS |
813 | goto ldx; |
814 | case BPF_LDX | BPF_MEM | BPF_H: | |
815 | /* emit 'movzx rax, word ptr [rax + off]' */ | |
e430f34e | 816 | EMIT3(add_2mod(0x48, src_reg, dst_reg), 0x0F, 0xB7); |
62258278 AS |
817 | goto ldx; |
818 | case BPF_LDX | BPF_MEM | BPF_W: | |
819 | /* emit 'mov eax, dword ptr [rax+0x14]' */ | |
e430f34e AS |
820 | if (is_ereg(dst_reg) || is_ereg(src_reg)) |
821 | EMIT2(add_2mod(0x40, src_reg, dst_reg), 0x8B); | |
62258278 AS |
822 | else |
823 | EMIT1(0x8B); | |
824 | goto ldx; | |
825 | case BPF_LDX | BPF_MEM | BPF_DW: | |
826 | /* emit 'mov rax, qword ptr [rax+0x14]' */ | |
e430f34e | 827 | EMIT2(add_2mod(0x48, src_reg, dst_reg), 0x8B); |
62258278 AS |
828 | ldx: /* if insn->off == 0 we can save one extra byte, but |
829 | * special case of x86 r13 which always needs an offset | |
830 | * is not worth the hassle | |
831 | */ | |
832 | if (is_imm8(insn->off)) | |
e430f34e | 833 | EMIT2(add_2reg(0x40, src_reg, dst_reg), insn->off); |
62258278 | 834 | else |
e430f34e | 835 | EMIT1_off32(add_2reg(0x80, src_reg, dst_reg), |
62258278 AS |
836 | insn->off); |
837 | break; | |
838 | ||
e430f34e | 839 | /* STX XADD: lock *(u32*)(dst_reg + off) += src_reg */ |
62258278 AS |
840 | case BPF_STX | BPF_XADD | BPF_W: |
841 | /* emit 'lock add dword ptr [rax + off], eax' */ | |
e430f34e AS |
842 | if (is_ereg(dst_reg) || is_ereg(src_reg)) |
843 | EMIT3(0xF0, add_2mod(0x40, dst_reg, src_reg), 0x01); | |
62258278 AS |
844 | else |
845 | EMIT2(0xF0, 0x01); | |
846 | goto xadd; | |
847 | case BPF_STX | BPF_XADD | BPF_DW: | |
e430f34e | 848 | EMIT3(0xF0, add_2mod(0x48, dst_reg, src_reg), 0x01); |
62258278 | 849 | xadd: if (is_imm8(insn->off)) |
e430f34e | 850 | EMIT2(add_2reg(0x40, dst_reg, src_reg), insn->off); |
62258278 | 851 | else |
e430f34e | 852 | EMIT1_off32(add_2reg(0x80, dst_reg, src_reg), |
62258278 AS |
853 | insn->off); |
854 | break; | |
855 | ||
856 | /* call */ | |
857 | case BPF_JMP | BPF_CALL: | |
e430f34e | 858 | func = (u8 *) __bpf_call_base + imm32; |
62258278 | 859 | jmp_offset = func - (image + addrs[i]); |
e0ee9c12 | 860 | if (seen_ld_abs) { |
17bedab2 | 861 | reload_skb_data = bpf_helper_changes_pkt_data(func); |
4e10df9a AS |
862 | if (reload_skb_data) { |
863 | EMIT1(0x57); /* push %rdi */ | |
864 | jmp_offset += 22; /* pop, mov, sub, mov */ | |
865 | } else { | |
866 | EMIT2(0x41, 0x52); /* push %r10 */ | |
867 | EMIT2(0x41, 0x51); /* push %r9 */ | |
868 | /* need to adjust jmp offset, since | |
869 | * pop %r9, pop %r10 take 4 bytes after call insn | |
870 | */ | |
871 | jmp_offset += 4; | |
872 | } | |
62258278 | 873 | } |
e430f34e | 874 | if (!imm32 || !is_simm32(jmp_offset)) { |
62258278 | 875 | pr_err("unsupported bpf func %d addr %p image %p\n", |
e430f34e | 876 | imm32, func, image); |
62258278 AS |
877 | return -EINVAL; |
878 | } | |
879 | EMIT1_off32(0xE8, jmp_offset); | |
e0ee9c12 | 880 | if (seen_ld_abs) { |
4e10df9a AS |
881 | if (reload_skb_data) { |
882 | EMIT1(0x5F); /* pop %rdi */ | |
883 | emit_load_skb_data_hlen(&prog); | |
884 | } else { | |
885 | EMIT2(0x41, 0x59); /* pop %r9 */ | |
886 | EMIT2(0x41, 0x5A); /* pop %r10 */ | |
887 | } | |
62258278 AS |
888 | } |
889 | break; | |
890 | ||
71189fa9 | 891 | case BPF_JMP | BPF_TAIL_CALL: |
b52f00e6 AS |
892 | emit_bpf_tail_call(&prog); |
893 | break; | |
894 | ||
62258278 AS |
895 | /* cond jump */ |
896 | case BPF_JMP | BPF_JEQ | BPF_X: | |
897 | case BPF_JMP | BPF_JNE | BPF_X: | |
898 | case BPF_JMP | BPF_JGT | BPF_X: | |
52afc51e | 899 | case BPF_JMP | BPF_JLT | BPF_X: |
62258278 | 900 | case BPF_JMP | BPF_JGE | BPF_X: |
52afc51e | 901 | case BPF_JMP | BPF_JLE | BPF_X: |
62258278 | 902 | case BPF_JMP | BPF_JSGT | BPF_X: |
52afc51e | 903 | case BPF_JMP | BPF_JSLT | BPF_X: |
62258278 | 904 | case BPF_JMP | BPF_JSGE | BPF_X: |
52afc51e | 905 | case BPF_JMP | BPF_JSLE | BPF_X: |
e430f34e AS |
906 | /* cmp dst_reg, src_reg */ |
907 | EMIT3(add_2mod(0x48, dst_reg, src_reg), 0x39, | |
908 | add_2reg(0xC0, dst_reg, src_reg)); | |
62258278 AS |
909 | goto emit_cond_jmp; |
910 | ||
911 | case BPF_JMP | BPF_JSET | BPF_X: | |
e430f34e AS |
912 | /* test dst_reg, src_reg */ |
913 | EMIT3(add_2mod(0x48, dst_reg, src_reg), 0x85, | |
914 | add_2reg(0xC0, dst_reg, src_reg)); | |
62258278 AS |
915 | goto emit_cond_jmp; |
916 | ||
917 | case BPF_JMP | BPF_JSET | BPF_K: | |
e430f34e AS |
918 | /* test dst_reg, imm32 */ |
919 | EMIT1(add_1mod(0x48, dst_reg)); | |
920 | EMIT2_off32(0xF7, add_1reg(0xC0, dst_reg), imm32); | |
62258278 AS |
921 | goto emit_cond_jmp; |
922 | ||
923 | case BPF_JMP | BPF_JEQ | BPF_K: | |
924 | case BPF_JMP | BPF_JNE | BPF_K: | |
925 | case BPF_JMP | BPF_JGT | BPF_K: | |
52afc51e | 926 | case BPF_JMP | BPF_JLT | BPF_K: |
62258278 | 927 | case BPF_JMP | BPF_JGE | BPF_K: |
52afc51e | 928 | case BPF_JMP | BPF_JLE | BPF_K: |
62258278 | 929 | case BPF_JMP | BPF_JSGT | BPF_K: |
52afc51e | 930 | case BPF_JMP | BPF_JSLT | BPF_K: |
62258278 | 931 | case BPF_JMP | BPF_JSGE | BPF_K: |
52afc51e | 932 | case BPF_JMP | BPF_JSLE | BPF_K: |
e430f34e AS |
933 | /* cmp dst_reg, imm8/32 */ |
934 | EMIT1(add_1mod(0x48, dst_reg)); | |
62258278 | 935 | |
e430f34e AS |
936 | if (is_imm8(imm32)) |
937 | EMIT3(0x83, add_1reg(0xF8, dst_reg), imm32); | |
62258278 | 938 | else |
e430f34e | 939 | EMIT2_off32(0x81, add_1reg(0xF8, dst_reg), imm32); |
62258278 AS |
940 | |
941 | emit_cond_jmp: /* convert BPF opcode to x86 */ | |
942 | switch (BPF_OP(insn->code)) { | |
943 | case BPF_JEQ: | |
944 | jmp_cond = X86_JE; | |
945 | break; | |
946 | case BPF_JSET: | |
947 | case BPF_JNE: | |
948 | jmp_cond = X86_JNE; | |
949 | break; | |
950 | case BPF_JGT: | |
951 | /* GT is unsigned '>', JA in x86 */ | |
952 | jmp_cond = X86_JA; | |
953 | break; | |
52afc51e DB |
954 | case BPF_JLT: |
955 | /* LT is unsigned '<', JB in x86 */ | |
956 | jmp_cond = X86_JB; | |
957 | break; | |
62258278 AS |
958 | case BPF_JGE: |
959 | /* GE is unsigned '>=', JAE in x86 */ | |
960 | jmp_cond = X86_JAE; | |
961 | break; | |
52afc51e DB |
962 | case BPF_JLE: |
963 | /* LE is unsigned '<=', JBE in x86 */ | |
964 | jmp_cond = X86_JBE; | |
965 | break; | |
62258278 AS |
966 | case BPF_JSGT: |
967 | /* signed '>', GT in x86 */ | |
968 | jmp_cond = X86_JG; | |
969 | break; | |
52afc51e DB |
970 | case BPF_JSLT: |
971 | /* signed '<', LT in x86 */ | |
972 | jmp_cond = X86_JL; | |
973 | break; | |
62258278 AS |
974 | case BPF_JSGE: |
975 | /* signed '>=', GE in x86 */ | |
976 | jmp_cond = X86_JGE; | |
977 | break; | |
52afc51e DB |
978 | case BPF_JSLE: |
979 | /* signed '<=', LE in x86 */ | |
980 | jmp_cond = X86_JLE; | |
981 | break; | |
62258278 AS |
982 | default: /* to silence gcc warning */ |
983 | return -EFAULT; | |
984 | } | |
985 | jmp_offset = addrs[i + insn->off] - addrs[i]; | |
986 | if (is_imm8(jmp_offset)) { | |
987 | EMIT2(jmp_cond, jmp_offset); | |
988 | } else if (is_simm32(jmp_offset)) { | |
989 | EMIT2_off32(0x0F, jmp_cond + 0x10, jmp_offset); | |
990 | } else { | |
991 | pr_err("cond_jmp gen bug %llx\n", jmp_offset); | |
992 | return -EFAULT; | |
993 | } | |
994 | ||
995 | break; | |
0a14842f | 996 | |
62258278 AS |
997 | case BPF_JMP | BPF_JA: |
998 | jmp_offset = addrs[i + insn->off] - addrs[i]; | |
999 | if (!jmp_offset) | |
1000 | /* optimize out nop jumps */ | |
1001 | break; | |
1002 | emit_jmp: | |
1003 | if (is_imm8(jmp_offset)) { | |
1004 | EMIT2(0xEB, jmp_offset); | |
1005 | } else if (is_simm32(jmp_offset)) { | |
1006 | EMIT1_off32(0xE9, jmp_offset); | |
1007 | } else { | |
1008 | pr_err("jmp gen bug %llx\n", jmp_offset); | |
1009 | return -EFAULT; | |
1010 | } | |
1011 | break; | |
1012 | ||
1013 | case BPF_LD | BPF_IND | BPF_W: | |
1014 | func = sk_load_word; | |
1015 | goto common_load; | |
1016 | case BPF_LD | BPF_ABS | BPF_W: | |
e430f34e | 1017 | func = CHOOSE_LOAD_FUNC(imm32, sk_load_word); |
e0ee9c12 AS |
1018 | common_load: |
1019 | ctx->seen_ld_abs = seen_ld_abs = true; | |
62258278 AS |
1020 | jmp_offset = func - (image + addrs[i]); |
1021 | if (!func || !is_simm32(jmp_offset)) { | |
1022 | pr_err("unsupported bpf func %d addr %p image %p\n", | |
e430f34e | 1023 | imm32, func, image); |
62258278 AS |
1024 | return -EINVAL; |
1025 | } | |
1026 | if (BPF_MODE(insn->code) == BPF_ABS) { | |
1027 | /* mov %esi, imm32 */ | |
e430f34e | 1028 | EMIT1_off32(0xBE, imm32); |
62258278 | 1029 | } else { |
e430f34e AS |
1030 | /* mov %rsi, src_reg */ |
1031 | EMIT_mov(BPF_REG_2, src_reg); | |
1032 | if (imm32) { | |
1033 | if (is_imm8(imm32)) | |
62258278 | 1034 | /* add %esi, imm8 */ |
e430f34e | 1035 | EMIT3(0x83, 0xC6, imm32); |
0a14842f | 1036 | else |
62258278 | 1037 | /* add %esi, imm32 */ |
e430f34e | 1038 | EMIT2_off32(0x81, 0xC6, imm32); |
0a14842f | 1039 | } |
62258278 AS |
1040 | } |
1041 | /* skb pointer is in R6 (%rbx), it will be copied into | |
1042 | * %rdi if skb_copy_bits() call is necessary. | |
1043 | * sk_load_* helpers also use %r10 and %r9d. | |
1044 | * See bpf_jit.S | |
1045 | */ | |
959a7579 DB |
1046 | if (seen_ax_reg) |
1047 | /* r10 = skb->data, mov %r10, off32(%rbx) */ | |
1048 | EMIT3_off32(0x4c, 0x8b, 0x93, | |
1049 | offsetof(struct sk_buff, data)); | |
62258278 AS |
1050 | EMIT1_off32(0xE8, jmp_offset); /* call */ |
1051 | break; | |
1052 | ||
1053 | case BPF_LD | BPF_IND | BPF_H: | |
1054 | func = sk_load_half; | |
1055 | goto common_load; | |
1056 | case BPF_LD | BPF_ABS | BPF_H: | |
e430f34e | 1057 | func = CHOOSE_LOAD_FUNC(imm32, sk_load_half); |
62258278 AS |
1058 | goto common_load; |
1059 | case BPF_LD | BPF_IND | BPF_B: | |
1060 | func = sk_load_byte; | |
1061 | goto common_load; | |
1062 | case BPF_LD | BPF_ABS | BPF_B: | |
e430f34e | 1063 | func = CHOOSE_LOAD_FUNC(imm32, sk_load_byte); |
62258278 AS |
1064 | goto common_load; |
1065 | ||
1066 | case BPF_JMP | BPF_EXIT: | |
769e0de6 | 1067 | if (seen_exit) { |
62258278 AS |
1068 | jmp_offset = ctx->cleanup_addr - addrs[i]; |
1069 | goto emit_jmp; | |
1070 | } | |
769e0de6 | 1071 | seen_exit = true; |
62258278 AS |
1072 | /* update cleanup_addr */ |
1073 | ctx->cleanup_addr = proglen; | |
177366bf AS |
1074 | /* mov rbx, qword ptr [rbp+0] */ |
1075 | EMIT4(0x48, 0x8B, 0x5D, 0); | |
1076 | /* mov r13, qword ptr [rbp+8] */ | |
1077 | EMIT4(0x4C, 0x8B, 0x6D, 8); | |
1078 | /* mov r14, qword ptr [rbp+16] */ | |
1079 | EMIT4(0x4C, 0x8B, 0x75, 16); | |
1080 | /* mov r15, qword ptr [rbp+24] */ | |
1081 | EMIT4(0x4C, 0x8B, 0x7D, 24); | |
1082 | ||
1083 | /* add rbp, AUX_STACK_SPACE */ | |
1084 | EMIT4(0x48, 0x83, 0xC5, AUX_STACK_SPACE); | |
62258278 AS |
1085 | EMIT1(0xC9); /* leave */ |
1086 | EMIT1(0xC3); /* ret */ | |
1087 | break; | |
1088 | ||
f3c2af7b | 1089 | default: |
62258278 AS |
1090 | /* By design x64 JIT should support all BPF instructions |
1091 | * This error will be seen if new instruction was added | |
1092 | * to interpreter, but not to JIT | |
7ae457c1 | 1093 | * or if there is junk in bpf_prog |
62258278 AS |
1094 | */ |
1095 | pr_err("bpf_jit: unknown opcode %02x\n", insn->code); | |
f3c2af7b AS |
1096 | return -EINVAL; |
1097 | } | |
62258278 | 1098 | |
f3c2af7b | 1099 | ilen = prog - temp; |
e0ee9c12 | 1100 | if (ilen > BPF_MAX_INSN_SIZE) { |
9383191d | 1101 | pr_err("bpf_jit: fatal insn size error\n"); |
e0ee9c12 AS |
1102 | return -EFAULT; |
1103 | } | |
1104 | ||
f3c2af7b AS |
1105 | if (image) { |
1106 | if (unlikely(proglen + ilen > oldproglen)) { | |
9383191d | 1107 | pr_err("bpf_jit: fatal error\n"); |
f3c2af7b | 1108 | return -EFAULT; |
0a14842f | 1109 | } |
f3c2af7b | 1110 | memcpy(image + proglen, temp, ilen); |
0a14842f | 1111 | } |
f3c2af7b AS |
1112 | proglen += ilen; |
1113 | addrs[i] = proglen; | |
1114 | prog = temp; | |
1115 | } | |
f3c2af7b AS |
1116 | return proglen; |
1117 | } | |
1118 | ||
1c2a088a AS |
1119 | struct x64_jit_data { |
1120 | struct bpf_binary_header *header; | |
1121 | int *addrs; | |
1122 | u8 *image; | |
1123 | int proglen; | |
1124 | struct jit_context ctx; | |
1125 | }; | |
1126 | ||
d1c55ab5 | 1127 | struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog) |
f3c2af7b AS |
1128 | { |
1129 | struct bpf_binary_header *header = NULL; | |
959a7579 | 1130 | struct bpf_prog *tmp, *orig_prog = prog; |
1c2a088a | 1131 | struct x64_jit_data *jit_data; |
f3c2af7b AS |
1132 | int proglen, oldproglen = 0; |
1133 | struct jit_context ctx = {}; | |
959a7579 | 1134 | bool tmp_blinded = false; |
1c2a088a | 1135 | bool extra_pass = false; |
f3c2af7b AS |
1136 | u8 *image = NULL; |
1137 | int *addrs; | |
1138 | int pass; | |
1139 | int i; | |
1140 | ||
60b58afc | 1141 | if (!prog->jit_requested) |
959a7579 DB |
1142 | return orig_prog; |
1143 | ||
1144 | tmp = bpf_jit_blind_constants(prog); | |
1145 | /* If blinding was requested and we failed during blinding, | |
1146 | * we must fall back to the interpreter. | |
1147 | */ | |
1148 | if (IS_ERR(tmp)) | |
1149 | return orig_prog; | |
1150 | if (tmp != prog) { | |
1151 | tmp_blinded = true; | |
1152 | prog = tmp; | |
1153 | } | |
0a14842f | 1154 | |
1c2a088a AS |
1155 | jit_data = prog->aux->jit_data; |
1156 | if (!jit_data) { | |
1157 | jit_data = kzalloc(sizeof(*jit_data), GFP_KERNEL); | |
1158 | if (!jit_data) { | |
1159 | prog = orig_prog; | |
1160 | goto out; | |
1161 | } | |
1162 | prog->aux->jit_data = jit_data; | |
1163 | } | |
1164 | addrs = jit_data->addrs; | |
1165 | if (addrs) { | |
1166 | ctx = jit_data->ctx; | |
1167 | oldproglen = jit_data->proglen; | |
1168 | image = jit_data->image; | |
1169 | header = jit_data->header; | |
1170 | extra_pass = true; | |
1171 | goto skip_init_addrs; | |
1172 | } | |
f3c2af7b | 1173 | addrs = kmalloc(prog->len * sizeof(*addrs), GFP_KERNEL); |
959a7579 DB |
1174 | if (!addrs) { |
1175 | prog = orig_prog; | |
1c2a088a | 1176 | goto out_addrs; |
959a7579 | 1177 | } |
f3c2af7b AS |
1178 | |
1179 | /* Before first pass, make a rough estimation of addrs[] | |
1180 | * each bpf instruction is translated to less than 64 bytes | |
1181 | */ | |
1182 | for (proglen = 0, i = 0; i < prog->len; i++) { | |
1183 | proglen += 64; | |
1184 | addrs[i] = proglen; | |
1185 | } | |
1186 | ctx.cleanup_addr = proglen; | |
1c2a088a | 1187 | skip_init_addrs: |
f3c2af7b | 1188 | |
3f7352bf AS |
1189 | /* JITed image shrinks with every pass and the loop iterates |
1190 | * until the image stops shrinking. Very large bpf programs | |
1191 | * may converge on the last pass. In such case do one more | |
1192 | * pass to emit the final image | |
1193 | */ | |
1194 | for (pass = 0; pass < 10 || image; pass++) { | |
f3c2af7b AS |
1195 | proglen = do_jit(prog, addrs, image, oldproglen, &ctx); |
1196 | if (proglen <= 0) { | |
1197 | image = NULL; | |
1198 | if (header) | |
738cbe72 | 1199 | bpf_jit_binary_free(header); |
959a7579 DB |
1200 | prog = orig_prog; |
1201 | goto out_addrs; | |
f3c2af7b | 1202 | } |
0a14842f | 1203 | if (image) { |
e0ee9c12 | 1204 | if (proglen != oldproglen) { |
f3c2af7b AS |
1205 | pr_err("bpf_jit: proglen=%d != oldproglen=%d\n", |
1206 | proglen, oldproglen); | |
959a7579 DB |
1207 | prog = orig_prog; |
1208 | goto out_addrs; | |
e0ee9c12 | 1209 | } |
0a14842f ED |
1210 | break; |
1211 | } | |
1212 | if (proglen == oldproglen) { | |
738cbe72 DB |
1213 | header = bpf_jit_binary_alloc(proglen, &image, |
1214 | 1, jit_fill_hole); | |
959a7579 DB |
1215 | if (!header) { |
1216 | prog = orig_prog; | |
1217 | goto out_addrs; | |
1218 | } | |
0a14842f ED |
1219 | } |
1220 | oldproglen = proglen; | |
1221 | } | |
79617801 | 1222 | |
0a14842f | 1223 | if (bpf_jit_enable > 1) |
485d6511 | 1224 | bpf_jit_dump(prog->len, proglen, pass + 1, image); |
0a14842f ED |
1225 | |
1226 | if (image) { | |
314beb9b | 1227 | bpf_flush_icache(header, image + proglen); |
1c2a088a AS |
1228 | if (!prog->is_func || extra_pass) { |
1229 | bpf_jit_binary_lock_ro(header); | |
1230 | } else { | |
1231 | jit_data->addrs = addrs; | |
1232 | jit_data->ctx = ctx; | |
1233 | jit_data->proglen = proglen; | |
1234 | jit_data->image = image; | |
1235 | jit_data->header = header; | |
1236 | } | |
f3c2af7b | 1237 | prog->bpf_func = (void *)image; |
a91263d5 | 1238 | prog->jited = 1; |
783d28dd | 1239 | prog->jited_len = proglen; |
9d5ecb09 DB |
1240 | } else { |
1241 | prog = orig_prog; | |
0a14842f | 1242 | } |
959a7579 | 1243 | |
1c2a088a | 1244 | if (!prog->is_func || extra_pass) { |
959a7579 | 1245 | out_addrs: |
1c2a088a AS |
1246 | kfree(addrs); |
1247 | kfree(jit_data); | |
1248 | prog->aux->jit_data = NULL; | |
1249 | } | |
959a7579 DB |
1250 | out: |
1251 | if (tmp_blinded) | |
1252 | bpf_jit_prog_release_other(prog, prog == orig_prog ? | |
1253 | tmp : orig_prog); | |
d1c55ab5 | 1254 | return prog; |
0a14842f | 1255 | } |