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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 | ||
177366bf AS |
200 | #define AUX_STACK_SPACE \ |
201 | (32 /* space for rbx, r13, r14, r15 */ + \ | |
b52f00e6 AS |
202 | 8 /* space for skb_copy_bits() buffer */) |
203 | ||
177366bf | 204 | #define PROLOGUE_SIZE 37 |
b52f00e6 AS |
205 | |
206 | /* emit x64 prologue code for BPF program and check it's size. | |
207 | * bpf_tail_call helper will skip it while jumping into another program | |
208 | */ | |
209 | static void emit_prologue(u8 **pprog) | |
0a14842f | 210 | { |
b52f00e6 AS |
211 | u8 *prog = *pprog; |
212 | int cnt = 0; | |
0a14842f | 213 | |
62258278 AS |
214 | EMIT1(0x55); /* push rbp */ |
215 | EMIT3(0x48, 0x89, 0xE5); /* mov rbp,rsp */ | |
0a14842f | 216 | |
177366bf AS |
217 | /* sub rsp, MAX_BPF_STACK + AUX_STACK_SPACE */ |
218 | EMIT3_off32(0x48, 0x81, 0xEC, MAX_BPF_STACK + AUX_STACK_SPACE); | |
219 | ||
220 | /* sub rbp, AUX_STACK_SPACE */ | |
221 | EMIT4(0x48, 0x83, 0xED, AUX_STACK_SPACE); | |
62258278 AS |
222 | |
223 | /* all classic BPF filters use R6(rbx) save it */ | |
224 | ||
177366bf AS |
225 | /* mov qword ptr [rbp+0],rbx */ |
226 | EMIT4(0x48, 0x89, 0x5D, 0); | |
62258278 | 227 | |
8fb575ca | 228 | /* bpf_convert_filter() maps classic BPF register X to R7 and uses R8 |
62258278 AS |
229 | * as temporary, so all tcpdump filters need to spill/fill R7(r13) and |
230 | * R8(r14). R9(r15) spill could be made conditional, but there is only | |
231 | * one 'bpf_error' return path out of helper functions inside bpf_jit.S | |
232 | * The overhead of extra spill is negligible for any filter other | |
233 | * than synthetic ones. Therefore not worth adding complexity. | |
234 | */ | |
235 | ||
177366bf AS |
236 | /* mov qword ptr [rbp+8],r13 */ |
237 | EMIT4(0x4C, 0x89, 0x6D, 8); | |
238 | /* mov qword ptr [rbp+16],r14 */ | |
239 | EMIT4(0x4C, 0x89, 0x75, 16); | |
240 | /* mov qword ptr [rbp+24],r15 */ | |
241 | EMIT4(0x4C, 0x89, 0x7D, 24); | |
62258278 | 242 | |
8b614aeb DB |
243 | /* Clear the tail call counter (tail_call_cnt): for eBPF tail calls |
244 | * we need to reset the counter to 0. It's done in two instructions, | |
245 | * resetting rax register to 0 (xor on eax gets 0 extended), and | |
246 | * moving it to the counter location. | |
247 | */ | |
62258278 | 248 | |
8b614aeb DB |
249 | /* xor eax, eax */ |
250 | EMIT2(0x31, 0xc0); | |
177366bf AS |
251 | /* mov qword ptr [rbp+32], rax */ |
252 | EMIT4(0x48, 0x89, 0x45, 32); | |
b52f00e6 AS |
253 | |
254 | BUILD_BUG_ON(cnt != PROLOGUE_SIZE); | |
255 | *pprog = prog; | |
256 | } | |
257 | ||
258 | /* generate the following code: | |
259 | * ... bpf_tail_call(void *ctx, struct bpf_array *array, u64 index) ... | |
260 | * if (index >= array->map.max_entries) | |
261 | * goto out; | |
262 | * if (++tail_call_cnt > MAX_TAIL_CALL_CNT) | |
263 | * goto out; | |
2a36f0b9 | 264 | * prog = array->ptrs[index]; |
b52f00e6 AS |
265 | * if (prog == NULL) |
266 | * goto out; | |
267 | * goto *(prog->bpf_func + prologue_size); | |
268 | * out: | |
269 | */ | |
270 | static void emit_bpf_tail_call(u8 **pprog) | |
271 | { | |
272 | u8 *prog = *pprog; | |
273 | int label1, label2, label3; | |
274 | int cnt = 0; | |
275 | ||
276 | /* rdi - pointer to ctx | |
277 | * rsi - pointer to bpf_array | |
278 | * rdx - index in bpf_array | |
279 | */ | |
280 | ||
281 | /* if (index >= array->map.max_entries) | |
282 | * goto out; | |
283 | */ | |
284 | EMIT4(0x48, 0x8B, 0x46, /* mov rax, qword ptr [rsi + 16] */ | |
285 | offsetof(struct bpf_array, map.max_entries)); | |
286 | EMIT3(0x48, 0x39, 0xD0); /* cmp rax, rdx */ | |
2482abb9 | 287 | #define OFFSET1 47 /* number of bytes to jump */ |
b52f00e6 AS |
288 | EMIT2(X86_JBE, OFFSET1); /* jbe out */ |
289 | label1 = cnt; | |
290 | ||
291 | /* if (tail_call_cnt > MAX_TAIL_CALL_CNT) | |
292 | * goto out; | |
293 | */ | |
177366bf | 294 | EMIT2_off32(0x8B, 0x85, 36); /* mov eax, dword ptr [rbp + 36] */ |
b52f00e6 | 295 | EMIT3(0x83, 0xF8, MAX_TAIL_CALL_CNT); /* cmp eax, MAX_TAIL_CALL_CNT */ |
2482abb9 | 296 | #define OFFSET2 36 |
b52f00e6 AS |
297 | EMIT2(X86_JA, OFFSET2); /* ja out */ |
298 | label2 = cnt; | |
299 | EMIT3(0x83, 0xC0, 0x01); /* add eax, 1 */ | |
177366bf | 300 | EMIT2_off32(0x89, 0x85, 36); /* mov dword ptr [rbp + 36], eax */ |
b52f00e6 | 301 | |
2a36f0b9 | 302 | /* prog = array->ptrs[index]; */ |
2482abb9 | 303 | EMIT4_off32(0x48, 0x8D, 0x84, 0xD6, /* lea rax, [rsi + rdx * 8 + offsetof(...)] */ |
2a36f0b9 | 304 | offsetof(struct bpf_array, ptrs)); |
b52f00e6 AS |
305 | EMIT3(0x48, 0x8B, 0x00); /* mov rax, qword ptr [rax] */ |
306 | ||
307 | /* if (prog == NULL) | |
308 | * goto out; | |
309 | */ | |
310 | EMIT4(0x48, 0x83, 0xF8, 0x00); /* cmp rax, 0 */ | |
311 | #define OFFSET3 10 | |
312 | EMIT2(X86_JE, OFFSET3); /* je out */ | |
313 | label3 = cnt; | |
314 | ||
315 | /* goto *(prog->bpf_func + prologue_size); */ | |
316 | EMIT4(0x48, 0x8B, 0x40, /* mov rax, qword ptr [rax + 32] */ | |
317 | offsetof(struct bpf_prog, bpf_func)); | |
318 | EMIT4(0x48, 0x83, 0xC0, PROLOGUE_SIZE); /* add rax, prologue_size */ | |
319 | ||
320 | /* now we're ready to jump into next BPF program | |
321 | * rdi == ctx (1st arg) | |
322 | * rax == prog->bpf_func + prologue_size | |
323 | */ | |
324 | EMIT2(0xFF, 0xE0); /* jmp rax */ | |
325 | ||
326 | /* out: */ | |
327 | BUILD_BUG_ON(cnt - label1 != OFFSET1); | |
328 | BUILD_BUG_ON(cnt - label2 != OFFSET2); | |
329 | BUILD_BUG_ON(cnt - label3 != OFFSET3); | |
330 | *pprog = prog; | |
331 | } | |
332 | ||
4e10df9a AS |
333 | |
334 | static void emit_load_skb_data_hlen(u8 **pprog) | |
335 | { | |
336 | u8 *prog = *pprog; | |
337 | int cnt = 0; | |
338 | ||
339 | /* r9d = skb->len - skb->data_len (headlen) | |
340 | * r10 = skb->data | |
341 | */ | |
342 | /* mov %r9d, off32(%rdi) */ | |
343 | EMIT3_off32(0x44, 0x8b, 0x8f, offsetof(struct sk_buff, len)); | |
344 | ||
345 | /* sub %r9d, off32(%rdi) */ | |
346 | EMIT3_off32(0x44, 0x2b, 0x8f, offsetof(struct sk_buff, data_len)); | |
347 | ||
348 | /* mov %r10, off32(%rdi) */ | |
349 | EMIT3_off32(0x4c, 0x8b, 0x97, offsetof(struct sk_buff, data)); | |
350 | *pprog = prog; | |
351 | } | |
352 | ||
b52f00e6 AS |
353 | static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image, |
354 | int oldproglen, struct jit_context *ctx) | |
355 | { | |
356 | struct bpf_insn *insn = bpf_prog->insnsi; | |
357 | int insn_cnt = bpf_prog->len; | |
358 | bool seen_ld_abs = ctx->seen_ld_abs | (oldproglen == 0); | |
959a7579 | 359 | bool seen_ax_reg = ctx->seen_ax_reg | (oldproglen == 0); |
b52f00e6 AS |
360 | bool seen_exit = false; |
361 | u8 temp[BPF_MAX_INSN_SIZE + BPF_INSN_SAFETY]; | |
362 | int i, cnt = 0; | |
363 | int proglen = 0; | |
364 | u8 *prog = temp; | |
365 | ||
366 | emit_prologue(&prog); | |
367 | ||
4e10df9a AS |
368 | if (seen_ld_abs) |
369 | emit_load_skb_data_hlen(&prog); | |
62258278 AS |
370 | |
371 | for (i = 0; i < insn_cnt; i++, insn++) { | |
e430f34e AS |
372 | const s32 imm32 = insn->imm; |
373 | u32 dst_reg = insn->dst_reg; | |
374 | u32 src_reg = insn->src_reg; | |
62258278 AS |
375 | u8 b1 = 0, b2 = 0, b3 = 0; |
376 | s64 jmp_offset; | |
377 | u8 jmp_cond; | |
4e10df9a | 378 | bool reload_skb_data; |
62258278 AS |
379 | int ilen; |
380 | u8 *func; | |
381 | ||
959a7579 DB |
382 | if (dst_reg == BPF_REG_AX || src_reg == BPF_REG_AX) |
383 | ctx->seen_ax_reg = seen_ax_reg = true; | |
384 | ||
62258278 AS |
385 | switch (insn->code) { |
386 | /* ALU */ | |
387 | case BPF_ALU | BPF_ADD | BPF_X: | |
388 | case BPF_ALU | BPF_SUB | BPF_X: | |
389 | case BPF_ALU | BPF_AND | BPF_X: | |
390 | case BPF_ALU | BPF_OR | BPF_X: | |
391 | case BPF_ALU | BPF_XOR | BPF_X: | |
392 | case BPF_ALU64 | BPF_ADD | BPF_X: | |
393 | case BPF_ALU64 | BPF_SUB | BPF_X: | |
394 | case BPF_ALU64 | BPF_AND | BPF_X: | |
395 | case BPF_ALU64 | BPF_OR | BPF_X: | |
396 | case BPF_ALU64 | BPF_XOR | BPF_X: | |
397 | switch (BPF_OP(insn->code)) { | |
398 | case BPF_ADD: b2 = 0x01; break; | |
399 | case BPF_SUB: b2 = 0x29; break; | |
400 | case BPF_AND: b2 = 0x21; break; | |
401 | case BPF_OR: b2 = 0x09; break; | |
402 | case BPF_XOR: b2 = 0x31; break; | |
0a14842f | 403 | } |
62258278 | 404 | if (BPF_CLASS(insn->code) == BPF_ALU64) |
e430f34e AS |
405 | EMIT1(add_2mod(0x48, dst_reg, src_reg)); |
406 | else if (is_ereg(dst_reg) || is_ereg(src_reg)) | |
407 | EMIT1(add_2mod(0x40, dst_reg, src_reg)); | |
408 | EMIT2(b2, add_2reg(0xC0, dst_reg, src_reg)); | |
62258278 | 409 | break; |
0a14842f | 410 | |
e430f34e | 411 | /* mov dst, src */ |
62258278 | 412 | case BPF_ALU64 | BPF_MOV | BPF_X: |
e430f34e | 413 | EMIT_mov(dst_reg, src_reg); |
0a14842f | 414 | break; |
0a14842f | 415 | |
e430f34e | 416 | /* mov32 dst, src */ |
62258278 | 417 | case BPF_ALU | BPF_MOV | BPF_X: |
e430f34e AS |
418 | if (is_ereg(dst_reg) || is_ereg(src_reg)) |
419 | EMIT1(add_2mod(0x40, dst_reg, src_reg)); | |
420 | EMIT2(0x89, add_2reg(0xC0, dst_reg, src_reg)); | |
62258278 | 421 | break; |
0a14842f | 422 | |
e430f34e | 423 | /* neg dst */ |
62258278 AS |
424 | case BPF_ALU | BPF_NEG: |
425 | case BPF_ALU64 | BPF_NEG: | |
426 | if (BPF_CLASS(insn->code) == BPF_ALU64) | |
e430f34e AS |
427 | EMIT1(add_1mod(0x48, dst_reg)); |
428 | else if (is_ereg(dst_reg)) | |
429 | EMIT1(add_1mod(0x40, dst_reg)); | |
430 | EMIT2(0xF7, add_1reg(0xD8, dst_reg)); | |
62258278 AS |
431 | break; |
432 | ||
433 | case BPF_ALU | BPF_ADD | BPF_K: | |
434 | case BPF_ALU | BPF_SUB | BPF_K: | |
435 | case BPF_ALU | BPF_AND | BPF_K: | |
436 | case BPF_ALU | BPF_OR | BPF_K: | |
437 | case BPF_ALU | BPF_XOR | BPF_K: | |
438 | case BPF_ALU64 | BPF_ADD | BPF_K: | |
439 | case BPF_ALU64 | BPF_SUB | BPF_K: | |
440 | case BPF_ALU64 | BPF_AND | BPF_K: | |
441 | case BPF_ALU64 | BPF_OR | BPF_K: | |
442 | case BPF_ALU64 | BPF_XOR | BPF_K: | |
443 | if (BPF_CLASS(insn->code) == BPF_ALU64) | |
e430f34e AS |
444 | EMIT1(add_1mod(0x48, dst_reg)); |
445 | else if (is_ereg(dst_reg)) | |
446 | EMIT1(add_1mod(0x40, dst_reg)); | |
62258278 AS |
447 | |
448 | switch (BPF_OP(insn->code)) { | |
449 | case BPF_ADD: b3 = 0xC0; break; | |
450 | case BPF_SUB: b3 = 0xE8; break; | |
451 | case BPF_AND: b3 = 0xE0; break; | |
452 | case BPF_OR: b3 = 0xC8; break; | |
453 | case BPF_XOR: b3 = 0xF0; break; | |
454 | } | |
455 | ||
e430f34e AS |
456 | if (is_imm8(imm32)) |
457 | EMIT3(0x83, add_1reg(b3, dst_reg), imm32); | |
62258278 | 458 | else |
e430f34e | 459 | EMIT2_off32(0x81, add_1reg(b3, dst_reg), imm32); |
62258278 AS |
460 | break; |
461 | ||
462 | case BPF_ALU64 | BPF_MOV | BPF_K: | |
463 | /* optimization: if imm32 is positive, | |
464 | * use 'mov eax, imm32' (which zero-extends imm32) | |
465 | * to save 2 bytes | |
466 | */ | |
e430f34e | 467 | if (imm32 < 0) { |
62258278 | 468 | /* 'mov rax, imm32' sign extends imm32 */ |
e430f34e | 469 | b1 = add_1mod(0x48, dst_reg); |
62258278 AS |
470 | b2 = 0xC7; |
471 | b3 = 0xC0; | |
e430f34e | 472 | EMIT3_off32(b1, b2, add_1reg(b3, dst_reg), imm32); |
0a14842f | 473 | break; |
62258278 AS |
474 | } |
475 | ||
476 | case BPF_ALU | BPF_MOV | BPF_K: | |
606c88a8 DB |
477 | /* optimization: if imm32 is zero, use 'xor <dst>,<dst>' |
478 | * to save 3 bytes. | |
479 | */ | |
480 | if (imm32 == 0) { | |
481 | if (is_ereg(dst_reg)) | |
482 | EMIT1(add_2mod(0x40, dst_reg, dst_reg)); | |
483 | b2 = 0x31; /* xor */ | |
484 | b3 = 0xC0; | |
485 | EMIT2(b2, add_2reg(b3, dst_reg, dst_reg)); | |
486 | break; | |
487 | } | |
488 | ||
62258278 | 489 | /* mov %eax, imm32 */ |
e430f34e AS |
490 | if (is_ereg(dst_reg)) |
491 | EMIT1(add_1mod(0x40, dst_reg)); | |
492 | EMIT1_off32(add_1reg(0xB8, dst_reg), imm32); | |
62258278 AS |
493 | break; |
494 | ||
02ab695b | 495 | case BPF_LD | BPF_IMM | BPF_DW: |
606c88a8 DB |
496 | /* optimization: if imm64 is zero, use 'xor <dst>,<dst>' |
497 | * to save 7 bytes. | |
498 | */ | |
499 | if (insn[0].imm == 0 && insn[1].imm == 0) { | |
500 | b1 = add_2mod(0x48, dst_reg, dst_reg); | |
501 | b2 = 0x31; /* xor */ | |
502 | b3 = 0xC0; | |
503 | EMIT3(b1, b2, add_2reg(b3, dst_reg, dst_reg)); | |
504 | ||
505 | insn++; | |
506 | i++; | |
507 | break; | |
508 | } | |
509 | ||
02ab695b AS |
510 | /* movabsq %rax, imm64 */ |
511 | EMIT2(add_1mod(0x48, dst_reg), add_1reg(0xB8, dst_reg)); | |
512 | EMIT(insn[0].imm, 4); | |
513 | EMIT(insn[1].imm, 4); | |
514 | ||
515 | insn++; | |
516 | i++; | |
517 | break; | |
518 | ||
e430f34e | 519 | /* dst %= src, dst /= src, dst %= imm32, dst /= imm32 */ |
62258278 AS |
520 | case BPF_ALU | BPF_MOD | BPF_X: |
521 | case BPF_ALU | BPF_DIV | BPF_X: | |
522 | case BPF_ALU | BPF_MOD | BPF_K: | |
523 | case BPF_ALU | BPF_DIV | BPF_K: | |
524 | case BPF_ALU64 | BPF_MOD | BPF_X: | |
525 | case BPF_ALU64 | BPF_DIV | BPF_X: | |
526 | case BPF_ALU64 | BPF_MOD | BPF_K: | |
527 | case BPF_ALU64 | BPF_DIV | BPF_K: | |
528 | EMIT1(0x50); /* push rax */ | |
529 | EMIT1(0x52); /* push rdx */ | |
530 | ||
531 | if (BPF_SRC(insn->code) == BPF_X) | |
e430f34e AS |
532 | /* mov r11, src_reg */ |
533 | EMIT_mov(AUX_REG, src_reg); | |
62258278 | 534 | else |
e430f34e AS |
535 | /* mov r11, imm32 */ |
536 | EMIT3_off32(0x49, 0xC7, 0xC3, imm32); | |
62258278 | 537 | |
e430f34e AS |
538 | /* mov rax, dst_reg */ |
539 | EMIT_mov(BPF_REG_0, dst_reg); | |
62258278 AS |
540 | |
541 | /* xor edx, edx | |
542 | * equivalent to 'xor rdx, rdx', but one byte less | |
543 | */ | |
544 | EMIT2(0x31, 0xd2); | |
545 | ||
546 | if (BPF_SRC(insn->code) == BPF_X) { | |
e430f34e | 547 | /* if (src_reg == 0) return 0 */ |
62258278 AS |
548 | |
549 | /* cmp r11, 0 */ | |
550 | EMIT4(0x49, 0x83, 0xFB, 0x00); | |
551 | ||
552 | /* jne .+9 (skip over pop, pop, xor and jmp) */ | |
553 | EMIT2(X86_JNE, 1 + 1 + 2 + 5); | |
554 | EMIT1(0x5A); /* pop rdx */ | |
555 | EMIT1(0x58); /* pop rax */ | |
556 | EMIT2(0x31, 0xc0); /* xor eax, eax */ | |
557 | ||
558 | /* jmp cleanup_addr | |
559 | * addrs[i] - 11, because there are 11 bytes | |
560 | * after this insn: div, mov, pop, pop, mov | |
561 | */ | |
562 | jmp_offset = ctx->cleanup_addr - (addrs[i] - 11); | |
563 | EMIT1_off32(0xE9, jmp_offset); | |
564 | } | |
565 | ||
566 | if (BPF_CLASS(insn->code) == BPF_ALU64) | |
567 | /* div r11 */ | |
568 | EMIT3(0x49, 0xF7, 0xF3); | |
569 | else | |
570 | /* div r11d */ | |
571 | EMIT3(0x41, 0xF7, 0xF3); | |
572 | ||
573 | if (BPF_OP(insn->code) == BPF_MOD) | |
574 | /* mov r11, rdx */ | |
575 | EMIT3(0x49, 0x89, 0xD3); | |
576 | else | |
577 | /* mov r11, rax */ | |
578 | EMIT3(0x49, 0x89, 0xC3); | |
579 | ||
580 | EMIT1(0x5A); /* pop rdx */ | |
581 | EMIT1(0x58); /* pop rax */ | |
582 | ||
e430f34e AS |
583 | /* mov dst_reg, r11 */ |
584 | EMIT_mov(dst_reg, AUX_REG); | |
62258278 AS |
585 | break; |
586 | ||
587 | case BPF_ALU | BPF_MUL | BPF_K: | |
588 | case BPF_ALU | BPF_MUL | BPF_X: | |
589 | case BPF_ALU64 | BPF_MUL | BPF_K: | |
590 | case BPF_ALU64 | BPF_MUL | BPF_X: | |
591 | EMIT1(0x50); /* push rax */ | |
592 | EMIT1(0x52); /* push rdx */ | |
593 | ||
e430f34e AS |
594 | /* mov r11, dst_reg */ |
595 | EMIT_mov(AUX_REG, dst_reg); | |
62258278 AS |
596 | |
597 | if (BPF_SRC(insn->code) == BPF_X) | |
e430f34e AS |
598 | /* mov rax, src_reg */ |
599 | EMIT_mov(BPF_REG_0, src_reg); | |
62258278 | 600 | else |
e430f34e AS |
601 | /* mov rax, imm32 */ |
602 | EMIT3_off32(0x48, 0xC7, 0xC0, imm32); | |
62258278 AS |
603 | |
604 | if (BPF_CLASS(insn->code) == BPF_ALU64) | |
605 | EMIT1(add_1mod(0x48, AUX_REG)); | |
606 | else if (is_ereg(AUX_REG)) | |
607 | EMIT1(add_1mod(0x40, AUX_REG)); | |
608 | /* mul(q) r11 */ | |
609 | EMIT2(0xF7, add_1reg(0xE0, AUX_REG)); | |
610 | ||
611 | /* mov r11, rax */ | |
612 | EMIT_mov(AUX_REG, BPF_REG_0); | |
613 | ||
614 | EMIT1(0x5A); /* pop rdx */ | |
615 | EMIT1(0x58); /* pop rax */ | |
616 | ||
e430f34e AS |
617 | /* mov dst_reg, r11 */ |
618 | EMIT_mov(dst_reg, AUX_REG); | |
62258278 AS |
619 | break; |
620 | ||
621 | /* shifts */ | |
622 | case BPF_ALU | BPF_LSH | BPF_K: | |
623 | case BPF_ALU | BPF_RSH | BPF_K: | |
624 | case BPF_ALU | BPF_ARSH | BPF_K: | |
625 | case BPF_ALU64 | BPF_LSH | BPF_K: | |
626 | case BPF_ALU64 | BPF_RSH | BPF_K: | |
627 | case BPF_ALU64 | BPF_ARSH | BPF_K: | |
628 | if (BPF_CLASS(insn->code) == BPF_ALU64) | |
e430f34e AS |
629 | EMIT1(add_1mod(0x48, dst_reg)); |
630 | else if (is_ereg(dst_reg)) | |
631 | EMIT1(add_1mod(0x40, dst_reg)); | |
62258278 AS |
632 | |
633 | switch (BPF_OP(insn->code)) { | |
634 | case BPF_LSH: b3 = 0xE0; break; | |
635 | case BPF_RSH: b3 = 0xE8; break; | |
636 | case BPF_ARSH: b3 = 0xF8; break; | |
637 | } | |
e430f34e | 638 | EMIT3(0xC1, add_1reg(b3, dst_reg), imm32); |
62258278 AS |
639 | break; |
640 | ||
72b603ee AS |
641 | case BPF_ALU | BPF_LSH | BPF_X: |
642 | case BPF_ALU | BPF_RSH | BPF_X: | |
643 | case BPF_ALU | BPF_ARSH | BPF_X: | |
644 | case BPF_ALU64 | BPF_LSH | BPF_X: | |
645 | case BPF_ALU64 | BPF_RSH | BPF_X: | |
646 | case BPF_ALU64 | BPF_ARSH | BPF_X: | |
647 | ||
648 | /* check for bad case when dst_reg == rcx */ | |
649 | if (dst_reg == BPF_REG_4) { | |
650 | /* mov r11, dst_reg */ | |
651 | EMIT_mov(AUX_REG, dst_reg); | |
652 | dst_reg = AUX_REG; | |
653 | } | |
654 | ||
655 | if (src_reg != BPF_REG_4) { /* common case */ | |
656 | EMIT1(0x51); /* push rcx */ | |
657 | ||
658 | /* mov rcx, src_reg */ | |
659 | EMIT_mov(BPF_REG_4, src_reg); | |
660 | } | |
661 | ||
662 | /* shl %rax, %cl | shr %rax, %cl | sar %rax, %cl */ | |
663 | if (BPF_CLASS(insn->code) == BPF_ALU64) | |
664 | EMIT1(add_1mod(0x48, dst_reg)); | |
665 | else if (is_ereg(dst_reg)) | |
666 | EMIT1(add_1mod(0x40, dst_reg)); | |
667 | ||
668 | switch (BPF_OP(insn->code)) { | |
669 | case BPF_LSH: b3 = 0xE0; break; | |
670 | case BPF_RSH: b3 = 0xE8; break; | |
671 | case BPF_ARSH: b3 = 0xF8; break; | |
672 | } | |
673 | EMIT2(0xD3, add_1reg(b3, dst_reg)); | |
674 | ||
675 | if (src_reg != BPF_REG_4) | |
676 | EMIT1(0x59); /* pop rcx */ | |
677 | ||
678 | if (insn->dst_reg == BPF_REG_4) | |
679 | /* mov dst_reg, r11 */ | |
680 | EMIT_mov(insn->dst_reg, AUX_REG); | |
681 | break; | |
682 | ||
62258278 | 683 | case BPF_ALU | BPF_END | BPF_FROM_BE: |
e430f34e | 684 | switch (imm32) { |
62258278 AS |
685 | case 16: |
686 | /* emit 'ror %ax, 8' to swap lower 2 bytes */ | |
687 | EMIT1(0x66); | |
e430f34e | 688 | if (is_ereg(dst_reg)) |
62258278 | 689 | EMIT1(0x41); |
e430f34e | 690 | EMIT3(0xC1, add_1reg(0xC8, dst_reg), 8); |
343f845b AS |
691 | |
692 | /* emit 'movzwl eax, ax' */ | |
693 | if (is_ereg(dst_reg)) | |
694 | EMIT3(0x45, 0x0F, 0xB7); | |
695 | else | |
696 | EMIT2(0x0F, 0xB7); | |
697 | EMIT1(add_2reg(0xC0, dst_reg, dst_reg)); | |
62258278 AS |
698 | break; |
699 | case 32: | |
700 | /* emit 'bswap eax' to swap lower 4 bytes */ | |
e430f34e | 701 | if (is_ereg(dst_reg)) |
62258278 | 702 | EMIT2(0x41, 0x0F); |
0a14842f | 703 | else |
62258278 | 704 | EMIT1(0x0F); |
e430f34e | 705 | EMIT1(add_1reg(0xC8, dst_reg)); |
0a14842f | 706 | break; |
62258278 AS |
707 | case 64: |
708 | /* emit 'bswap rax' to swap 8 bytes */ | |
e430f34e AS |
709 | EMIT3(add_1mod(0x48, dst_reg), 0x0F, |
710 | add_1reg(0xC8, dst_reg)); | |
3b58908a ED |
711 | break; |
712 | } | |
62258278 AS |
713 | break; |
714 | ||
715 | case BPF_ALU | BPF_END | BPF_FROM_LE: | |
343f845b AS |
716 | switch (imm32) { |
717 | case 16: | |
718 | /* emit 'movzwl eax, ax' to zero extend 16-bit | |
719 | * into 64 bit | |
720 | */ | |
721 | if (is_ereg(dst_reg)) | |
722 | EMIT3(0x45, 0x0F, 0xB7); | |
723 | else | |
724 | EMIT2(0x0F, 0xB7); | |
725 | EMIT1(add_2reg(0xC0, dst_reg, dst_reg)); | |
726 | break; | |
727 | case 32: | |
728 | /* emit 'mov eax, eax' to clear upper 32-bits */ | |
729 | if (is_ereg(dst_reg)) | |
730 | EMIT1(0x45); | |
731 | EMIT2(0x89, add_2reg(0xC0, dst_reg, dst_reg)); | |
732 | break; | |
733 | case 64: | |
734 | /* nop */ | |
735 | break; | |
736 | } | |
62258278 AS |
737 | break; |
738 | ||
e430f34e | 739 | /* ST: *(u8*)(dst_reg + off) = imm */ |
62258278 | 740 | case BPF_ST | BPF_MEM | BPF_B: |
e430f34e | 741 | if (is_ereg(dst_reg)) |
62258278 AS |
742 | EMIT2(0x41, 0xC6); |
743 | else | |
744 | EMIT1(0xC6); | |
745 | goto st; | |
746 | case BPF_ST | BPF_MEM | BPF_H: | |
e430f34e | 747 | if (is_ereg(dst_reg)) |
62258278 AS |
748 | EMIT3(0x66, 0x41, 0xC7); |
749 | else | |
750 | EMIT2(0x66, 0xC7); | |
751 | goto st; | |
752 | case BPF_ST | BPF_MEM | BPF_W: | |
e430f34e | 753 | if (is_ereg(dst_reg)) |
62258278 AS |
754 | EMIT2(0x41, 0xC7); |
755 | else | |
756 | EMIT1(0xC7); | |
757 | goto st; | |
758 | case BPF_ST | BPF_MEM | BPF_DW: | |
e430f34e | 759 | EMIT2(add_1mod(0x48, dst_reg), 0xC7); |
62258278 AS |
760 | |
761 | st: if (is_imm8(insn->off)) | |
e430f34e | 762 | EMIT2(add_1reg(0x40, dst_reg), insn->off); |
62258278 | 763 | else |
e430f34e | 764 | EMIT1_off32(add_1reg(0x80, dst_reg), insn->off); |
62258278 | 765 | |
e430f34e | 766 | EMIT(imm32, bpf_size_to_x86_bytes(BPF_SIZE(insn->code))); |
62258278 AS |
767 | break; |
768 | ||
e430f34e | 769 | /* STX: *(u8*)(dst_reg + off) = src_reg */ |
62258278 AS |
770 | case BPF_STX | BPF_MEM | BPF_B: |
771 | /* emit 'mov byte ptr [rax + off], al' */ | |
e430f34e | 772 | if (is_ereg(dst_reg) || is_ereg(src_reg) || |
62258278 | 773 | /* have to add extra byte for x86 SIL, DIL regs */ |
e430f34e AS |
774 | src_reg == BPF_REG_1 || src_reg == BPF_REG_2) |
775 | EMIT2(add_2mod(0x40, dst_reg, src_reg), 0x88); | |
62258278 AS |
776 | else |
777 | EMIT1(0x88); | |
778 | goto stx; | |
779 | case BPF_STX | BPF_MEM | BPF_H: | |
e430f34e AS |
780 | if (is_ereg(dst_reg) || is_ereg(src_reg)) |
781 | EMIT3(0x66, add_2mod(0x40, dst_reg, src_reg), 0x89); | |
62258278 AS |
782 | else |
783 | EMIT2(0x66, 0x89); | |
784 | goto stx; | |
785 | case BPF_STX | BPF_MEM | BPF_W: | |
e430f34e AS |
786 | if (is_ereg(dst_reg) || is_ereg(src_reg)) |
787 | EMIT2(add_2mod(0x40, dst_reg, src_reg), 0x89); | |
62258278 AS |
788 | else |
789 | EMIT1(0x89); | |
790 | goto stx; | |
791 | case BPF_STX | BPF_MEM | BPF_DW: | |
e430f34e | 792 | EMIT2(add_2mod(0x48, dst_reg, src_reg), 0x89); |
62258278 | 793 | stx: if (is_imm8(insn->off)) |
e430f34e | 794 | EMIT2(add_2reg(0x40, dst_reg, src_reg), insn->off); |
62258278 | 795 | else |
e430f34e | 796 | EMIT1_off32(add_2reg(0x80, dst_reg, src_reg), |
62258278 AS |
797 | insn->off); |
798 | break; | |
799 | ||
e430f34e | 800 | /* LDX: dst_reg = *(u8*)(src_reg + off) */ |
62258278 AS |
801 | case BPF_LDX | BPF_MEM | BPF_B: |
802 | /* emit 'movzx rax, byte ptr [rax + off]' */ | |
e430f34e | 803 | EMIT3(add_2mod(0x48, src_reg, dst_reg), 0x0F, 0xB6); |
62258278 AS |
804 | goto ldx; |
805 | case BPF_LDX | BPF_MEM | BPF_H: | |
806 | /* emit 'movzx rax, word ptr [rax + off]' */ | |
e430f34e | 807 | EMIT3(add_2mod(0x48, src_reg, dst_reg), 0x0F, 0xB7); |
62258278 AS |
808 | goto ldx; |
809 | case BPF_LDX | BPF_MEM | BPF_W: | |
810 | /* emit 'mov eax, dword ptr [rax+0x14]' */ | |
e430f34e AS |
811 | if (is_ereg(dst_reg) || is_ereg(src_reg)) |
812 | EMIT2(add_2mod(0x40, src_reg, dst_reg), 0x8B); | |
62258278 AS |
813 | else |
814 | EMIT1(0x8B); | |
815 | goto ldx; | |
816 | case BPF_LDX | BPF_MEM | BPF_DW: | |
817 | /* emit 'mov rax, qword ptr [rax+0x14]' */ | |
e430f34e | 818 | EMIT2(add_2mod(0x48, src_reg, dst_reg), 0x8B); |
62258278 AS |
819 | ldx: /* if insn->off == 0 we can save one extra byte, but |
820 | * special case of x86 r13 which always needs an offset | |
821 | * is not worth the hassle | |
822 | */ | |
823 | if (is_imm8(insn->off)) | |
e430f34e | 824 | EMIT2(add_2reg(0x40, src_reg, dst_reg), insn->off); |
62258278 | 825 | else |
e430f34e | 826 | EMIT1_off32(add_2reg(0x80, src_reg, dst_reg), |
62258278 AS |
827 | insn->off); |
828 | break; | |
829 | ||
e430f34e | 830 | /* STX XADD: lock *(u32*)(dst_reg + off) += src_reg */ |
62258278 AS |
831 | case BPF_STX | BPF_XADD | BPF_W: |
832 | /* emit 'lock add dword ptr [rax + off], eax' */ | |
e430f34e AS |
833 | if (is_ereg(dst_reg) || is_ereg(src_reg)) |
834 | EMIT3(0xF0, add_2mod(0x40, dst_reg, src_reg), 0x01); | |
62258278 AS |
835 | else |
836 | EMIT2(0xF0, 0x01); | |
837 | goto xadd; | |
838 | case BPF_STX | BPF_XADD | BPF_DW: | |
e430f34e | 839 | EMIT3(0xF0, add_2mod(0x48, dst_reg, src_reg), 0x01); |
62258278 | 840 | xadd: if (is_imm8(insn->off)) |
e430f34e | 841 | EMIT2(add_2reg(0x40, dst_reg, src_reg), insn->off); |
62258278 | 842 | else |
e430f34e | 843 | EMIT1_off32(add_2reg(0x80, dst_reg, src_reg), |
62258278 AS |
844 | insn->off); |
845 | break; | |
846 | ||
847 | /* call */ | |
848 | case BPF_JMP | BPF_CALL: | |
e430f34e | 849 | func = (u8 *) __bpf_call_base + imm32; |
62258278 | 850 | jmp_offset = func - (image + addrs[i]); |
e0ee9c12 | 851 | if (seen_ld_abs) { |
17bedab2 | 852 | reload_skb_data = bpf_helper_changes_pkt_data(func); |
4e10df9a AS |
853 | if (reload_skb_data) { |
854 | EMIT1(0x57); /* push %rdi */ | |
855 | jmp_offset += 22; /* pop, mov, sub, mov */ | |
856 | } else { | |
857 | EMIT2(0x41, 0x52); /* push %r10 */ | |
858 | EMIT2(0x41, 0x51); /* push %r9 */ | |
859 | /* need to adjust jmp offset, since | |
860 | * pop %r9, pop %r10 take 4 bytes after call insn | |
861 | */ | |
862 | jmp_offset += 4; | |
863 | } | |
62258278 | 864 | } |
e430f34e | 865 | if (!imm32 || !is_simm32(jmp_offset)) { |
62258278 | 866 | pr_err("unsupported bpf func %d addr %p image %p\n", |
e430f34e | 867 | imm32, func, image); |
62258278 AS |
868 | return -EINVAL; |
869 | } | |
870 | EMIT1_off32(0xE8, jmp_offset); | |
e0ee9c12 | 871 | if (seen_ld_abs) { |
4e10df9a AS |
872 | if (reload_skb_data) { |
873 | EMIT1(0x5F); /* pop %rdi */ | |
874 | emit_load_skb_data_hlen(&prog); | |
875 | } else { | |
876 | EMIT2(0x41, 0x59); /* pop %r9 */ | |
877 | EMIT2(0x41, 0x5A); /* pop %r10 */ | |
878 | } | |
62258278 AS |
879 | } |
880 | break; | |
881 | ||
71189fa9 | 882 | case BPF_JMP | BPF_TAIL_CALL: |
b52f00e6 AS |
883 | emit_bpf_tail_call(&prog); |
884 | break; | |
885 | ||
62258278 AS |
886 | /* cond jump */ |
887 | case BPF_JMP | BPF_JEQ | BPF_X: | |
888 | case BPF_JMP | BPF_JNE | BPF_X: | |
889 | case BPF_JMP | BPF_JGT | BPF_X: | |
890 | case BPF_JMP | BPF_JGE | BPF_X: | |
891 | case BPF_JMP | BPF_JSGT | BPF_X: | |
892 | case BPF_JMP | BPF_JSGE | BPF_X: | |
e430f34e AS |
893 | /* cmp dst_reg, src_reg */ |
894 | EMIT3(add_2mod(0x48, dst_reg, src_reg), 0x39, | |
895 | add_2reg(0xC0, dst_reg, src_reg)); | |
62258278 AS |
896 | goto emit_cond_jmp; |
897 | ||
898 | case BPF_JMP | BPF_JSET | BPF_X: | |
e430f34e AS |
899 | /* test dst_reg, src_reg */ |
900 | EMIT3(add_2mod(0x48, dst_reg, src_reg), 0x85, | |
901 | add_2reg(0xC0, dst_reg, src_reg)); | |
62258278 AS |
902 | goto emit_cond_jmp; |
903 | ||
904 | case BPF_JMP | BPF_JSET | BPF_K: | |
e430f34e AS |
905 | /* test dst_reg, imm32 */ |
906 | EMIT1(add_1mod(0x48, dst_reg)); | |
907 | EMIT2_off32(0xF7, add_1reg(0xC0, dst_reg), imm32); | |
62258278 AS |
908 | goto emit_cond_jmp; |
909 | ||
910 | case BPF_JMP | BPF_JEQ | BPF_K: | |
911 | case BPF_JMP | BPF_JNE | BPF_K: | |
912 | case BPF_JMP | BPF_JGT | BPF_K: | |
913 | case BPF_JMP | BPF_JGE | BPF_K: | |
914 | case BPF_JMP | BPF_JSGT | BPF_K: | |
915 | case BPF_JMP | BPF_JSGE | BPF_K: | |
e430f34e AS |
916 | /* cmp dst_reg, imm8/32 */ |
917 | EMIT1(add_1mod(0x48, dst_reg)); | |
62258278 | 918 | |
e430f34e AS |
919 | if (is_imm8(imm32)) |
920 | EMIT3(0x83, add_1reg(0xF8, dst_reg), imm32); | |
62258278 | 921 | else |
e430f34e | 922 | EMIT2_off32(0x81, add_1reg(0xF8, dst_reg), imm32); |
62258278 AS |
923 | |
924 | emit_cond_jmp: /* convert BPF opcode to x86 */ | |
925 | switch (BPF_OP(insn->code)) { | |
926 | case BPF_JEQ: | |
927 | jmp_cond = X86_JE; | |
928 | break; | |
929 | case BPF_JSET: | |
930 | case BPF_JNE: | |
931 | jmp_cond = X86_JNE; | |
932 | break; | |
933 | case BPF_JGT: | |
934 | /* GT is unsigned '>', JA in x86 */ | |
935 | jmp_cond = X86_JA; | |
936 | break; | |
937 | case BPF_JGE: | |
938 | /* GE is unsigned '>=', JAE in x86 */ | |
939 | jmp_cond = X86_JAE; | |
940 | break; | |
941 | case BPF_JSGT: | |
942 | /* signed '>', GT in x86 */ | |
943 | jmp_cond = X86_JG; | |
944 | break; | |
945 | case BPF_JSGE: | |
946 | /* signed '>=', GE in x86 */ | |
947 | jmp_cond = X86_JGE; | |
948 | break; | |
949 | default: /* to silence gcc warning */ | |
950 | return -EFAULT; | |
951 | } | |
952 | jmp_offset = addrs[i + insn->off] - addrs[i]; | |
953 | if (is_imm8(jmp_offset)) { | |
954 | EMIT2(jmp_cond, jmp_offset); | |
955 | } else if (is_simm32(jmp_offset)) { | |
956 | EMIT2_off32(0x0F, jmp_cond + 0x10, jmp_offset); | |
957 | } else { | |
958 | pr_err("cond_jmp gen bug %llx\n", jmp_offset); | |
959 | return -EFAULT; | |
960 | } | |
961 | ||
962 | break; | |
0a14842f | 963 | |
62258278 AS |
964 | case BPF_JMP | BPF_JA: |
965 | jmp_offset = addrs[i + insn->off] - addrs[i]; | |
966 | if (!jmp_offset) | |
967 | /* optimize out nop jumps */ | |
968 | break; | |
969 | emit_jmp: | |
970 | if (is_imm8(jmp_offset)) { | |
971 | EMIT2(0xEB, jmp_offset); | |
972 | } else if (is_simm32(jmp_offset)) { | |
973 | EMIT1_off32(0xE9, jmp_offset); | |
974 | } else { | |
975 | pr_err("jmp gen bug %llx\n", jmp_offset); | |
976 | return -EFAULT; | |
977 | } | |
978 | break; | |
979 | ||
980 | case BPF_LD | BPF_IND | BPF_W: | |
981 | func = sk_load_word; | |
982 | goto common_load; | |
983 | case BPF_LD | BPF_ABS | BPF_W: | |
e430f34e | 984 | func = CHOOSE_LOAD_FUNC(imm32, sk_load_word); |
e0ee9c12 AS |
985 | common_load: |
986 | ctx->seen_ld_abs = seen_ld_abs = true; | |
62258278 AS |
987 | jmp_offset = func - (image + addrs[i]); |
988 | if (!func || !is_simm32(jmp_offset)) { | |
989 | pr_err("unsupported bpf func %d addr %p image %p\n", | |
e430f34e | 990 | imm32, func, image); |
62258278 AS |
991 | return -EINVAL; |
992 | } | |
993 | if (BPF_MODE(insn->code) == BPF_ABS) { | |
994 | /* mov %esi, imm32 */ | |
e430f34e | 995 | EMIT1_off32(0xBE, imm32); |
62258278 | 996 | } else { |
e430f34e AS |
997 | /* mov %rsi, src_reg */ |
998 | EMIT_mov(BPF_REG_2, src_reg); | |
999 | if (imm32) { | |
1000 | if (is_imm8(imm32)) | |
62258278 | 1001 | /* add %esi, imm8 */ |
e430f34e | 1002 | EMIT3(0x83, 0xC6, imm32); |
0a14842f | 1003 | else |
62258278 | 1004 | /* add %esi, imm32 */ |
e430f34e | 1005 | EMIT2_off32(0x81, 0xC6, imm32); |
0a14842f | 1006 | } |
62258278 AS |
1007 | } |
1008 | /* skb pointer is in R6 (%rbx), it will be copied into | |
1009 | * %rdi if skb_copy_bits() call is necessary. | |
1010 | * sk_load_* helpers also use %r10 and %r9d. | |
1011 | * See bpf_jit.S | |
1012 | */ | |
959a7579 DB |
1013 | if (seen_ax_reg) |
1014 | /* r10 = skb->data, mov %r10, off32(%rbx) */ | |
1015 | EMIT3_off32(0x4c, 0x8b, 0x93, | |
1016 | offsetof(struct sk_buff, data)); | |
62258278 AS |
1017 | EMIT1_off32(0xE8, jmp_offset); /* call */ |
1018 | break; | |
1019 | ||
1020 | case BPF_LD | BPF_IND | BPF_H: | |
1021 | func = sk_load_half; | |
1022 | goto common_load; | |
1023 | case BPF_LD | BPF_ABS | BPF_H: | |
e430f34e | 1024 | func = CHOOSE_LOAD_FUNC(imm32, sk_load_half); |
62258278 AS |
1025 | goto common_load; |
1026 | case BPF_LD | BPF_IND | BPF_B: | |
1027 | func = sk_load_byte; | |
1028 | goto common_load; | |
1029 | case BPF_LD | BPF_ABS | BPF_B: | |
e430f34e | 1030 | func = CHOOSE_LOAD_FUNC(imm32, sk_load_byte); |
62258278 AS |
1031 | goto common_load; |
1032 | ||
1033 | case BPF_JMP | BPF_EXIT: | |
769e0de6 | 1034 | if (seen_exit) { |
62258278 AS |
1035 | jmp_offset = ctx->cleanup_addr - addrs[i]; |
1036 | goto emit_jmp; | |
1037 | } | |
769e0de6 | 1038 | seen_exit = true; |
62258278 AS |
1039 | /* update cleanup_addr */ |
1040 | ctx->cleanup_addr = proglen; | |
177366bf AS |
1041 | /* mov rbx, qword ptr [rbp+0] */ |
1042 | EMIT4(0x48, 0x8B, 0x5D, 0); | |
1043 | /* mov r13, qword ptr [rbp+8] */ | |
1044 | EMIT4(0x4C, 0x8B, 0x6D, 8); | |
1045 | /* mov r14, qword ptr [rbp+16] */ | |
1046 | EMIT4(0x4C, 0x8B, 0x75, 16); | |
1047 | /* mov r15, qword ptr [rbp+24] */ | |
1048 | EMIT4(0x4C, 0x8B, 0x7D, 24); | |
1049 | ||
1050 | /* add rbp, AUX_STACK_SPACE */ | |
1051 | EMIT4(0x48, 0x83, 0xC5, AUX_STACK_SPACE); | |
62258278 AS |
1052 | EMIT1(0xC9); /* leave */ |
1053 | EMIT1(0xC3); /* ret */ | |
1054 | break; | |
1055 | ||
f3c2af7b | 1056 | default: |
62258278 AS |
1057 | /* By design x64 JIT should support all BPF instructions |
1058 | * This error will be seen if new instruction was added | |
1059 | * to interpreter, but not to JIT | |
7ae457c1 | 1060 | * or if there is junk in bpf_prog |
62258278 AS |
1061 | */ |
1062 | pr_err("bpf_jit: unknown opcode %02x\n", insn->code); | |
f3c2af7b AS |
1063 | return -EINVAL; |
1064 | } | |
62258278 | 1065 | |
f3c2af7b | 1066 | ilen = prog - temp; |
e0ee9c12 | 1067 | if (ilen > BPF_MAX_INSN_SIZE) { |
9383191d | 1068 | pr_err("bpf_jit: fatal insn size error\n"); |
e0ee9c12 AS |
1069 | return -EFAULT; |
1070 | } | |
1071 | ||
f3c2af7b AS |
1072 | if (image) { |
1073 | if (unlikely(proglen + ilen > oldproglen)) { | |
9383191d | 1074 | pr_err("bpf_jit: fatal error\n"); |
f3c2af7b | 1075 | return -EFAULT; |
0a14842f | 1076 | } |
f3c2af7b | 1077 | memcpy(image + proglen, temp, ilen); |
0a14842f | 1078 | } |
f3c2af7b AS |
1079 | proglen += ilen; |
1080 | addrs[i] = proglen; | |
1081 | prog = temp; | |
1082 | } | |
f3c2af7b AS |
1083 | return proglen; |
1084 | } | |
1085 | ||
d1c55ab5 | 1086 | struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog) |
f3c2af7b AS |
1087 | { |
1088 | struct bpf_binary_header *header = NULL; | |
959a7579 | 1089 | struct bpf_prog *tmp, *orig_prog = prog; |
f3c2af7b AS |
1090 | int proglen, oldproglen = 0; |
1091 | struct jit_context ctx = {}; | |
959a7579 | 1092 | bool tmp_blinded = false; |
f3c2af7b AS |
1093 | u8 *image = NULL; |
1094 | int *addrs; | |
1095 | int pass; | |
1096 | int i; | |
1097 | ||
1098 | if (!bpf_jit_enable) | |
959a7579 DB |
1099 | return orig_prog; |
1100 | ||
1101 | tmp = bpf_jit_blind_constants(prog); | |
1102 | /* If blinding was requested and we failed during blinding, | |
1103 | * we must fall back to the interpreter. | |
1104 | */ | |
1105 | if (IS_ERR(tmp)) | |
1106 | return orig_prog; | |
1107 | if (tmp != prog) { | |
1108 | tmp_blinded = true; | |
1109 | prog = tmp; | |
1110 | } | |
0a14842f | 1111 | |
f3c2af7b | 1112 | addrs = kmalloc(prog->len * sizeof(*addrs), GFP_KERNEL); |
959a7579 DB |
1113 | if (!addrs) { |
1114 | prog = orig_prog; | |
1115 | goto out; | |
1116 | } | |
f3c2af7b AS |
1117 | |
1118 | /* Before first pass, make a rough estimation of addrs[] | |
1119 | * each bpf instruction is translated to less than 64 bytes | |
1120 | */ | |
1121 | for (proglen = 0, i = 0; i < prog->len; i++) { | |
1122 | proglen += 64; | |
1123 | addrs[i] = proglen; | |
1124 | } | |
1125 | ctx.cleanup_addr = proglen; | |
f3c2af7b | 1126 | |
3f7352bf AS |
1127 | /* JITed image shrinks with every pass and the loop iterates |
1128 | * until the image stops shrinking. Very large bpf programs | |
1129 | * may converge on the last pass. In such case do one more | |
1130 | * pass to emit the final image | |
1131 | */ | |
1132 | for (pass = 0; pass < 10 || image; pass++) { | |
f3c2af7b AS |
1133 | proglen = do_jit(prog, addrs, image, oldproglen, &ctx); |
1134 | if (proglen <= 0) { | |
1135 | image = NULL; | |
1136 | if (header) | |
738cbe72 | 1137 | bpf_jit_binary_free(header); |
959a7579 DB |
1138 | prog = orig_prog; |
1139 | goto out_addrs; | |
f3c2af7b | 1140 | } |
0a14842f | 1141 | if (image) { |
e0ee9c12 | 1142 | if (proglen != oldproglen) { |
f3c2af7b AS |
1143 | pr_err("bpf_jit: proglen=%d != oldproglen=%d\n", |
1144 | proglen, oldproglen); | |
959a7579 DB |
1145 | prog = orig_prog; |
1146 | goto out_addrs; | |
e0ee9c12 | 1147 | } |
0a14842f ED |
1148 | break; |
1149 | } | |
1150 | if (proglen == oldproglen) { | |
738cbe72 DB |
1151 | header = bpf_jit_binary_alloc(proglen, &image, |
1152 | 1, jit_fill_hole); | |
959a7579 DB |
1153 | if (!header) { |
1154 | prog = orig_prog; | |
1155 | goto out_addrs; | |
1156 | } | |
0a14842f ED |
1157 | } |
1158 | oldproglen = proglen; | |
1159 | } | |
79617801 | 1160 | |
0a14842f | 1161 | if (bpf_jit_enable > 1) |
485d6511 | 1162 | bpf_jit_dump(prog->len, proglen, pass + 1, image); |
0a14842f ED |
1163 | |
1164 | if (image) { | |
314beb9b | 1165 | bpf_flush_icache(header, image + proglen); |
9d876e79 | 1166 | bpf_jit_binary_lock_ro(header); |
f3c2af7b | 1167 | prog->bpf_func = (void *)image; |
a91263d5 | 1168 | prog->jited = 1; |
9d5ecb09 DB |
1169 | } else { |
1170 | prog = orig_prog; | |
0a14842f | 1171 | } |
959a7579 DB |
1172 | |
1173 | out_addrs: | |
0a14842f | 1174 | kfree(addrs); |
959a7579 DB |
1175 | out: |
1176 | if (tmp_blinded) | |
1177 | bpf_jit_prog_release_other(prog, prog == orig_prog ? | |
1178 | tmp : orig_prog); | |
d1c55ab5 | 1179 | return prog; |
0a14842f | 1180 | } |