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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> |
29fed5fa | 16 | #include <asm/nospec-branch.h> |
b52f00e6 | 17 | #include <linux/bpf.h> |
0a14842f | 18 | |
0a14842f ED |
19 | int bpf_jit_enable __read_mostly; |
20 | ||
21 | /* | |
22 | * assembly code in arch/x86/net/bpf_jit.S | |
23 | */ | |
62258278 | 24 | extern u8 sk_load_word[], sk_load_half[], sk_load_byte[]; |
a998d434 | 25 | extern u8 sk_load_word_positive_offset[], sk_load_half_positive_offset[]; |
62258278 | 26 | extern u8 sk_load_byte_positive_offset[]; |
a998d434 | 27 | extern u8 sk_load_word_negative_offset[], sk_load_half_negative_offset[]; |
62258278 | 28 | extern u8 sk_load_byte_negative_offset[]; |
0a14842f | 29 | |
5cccc702 | 30 | static u8 *emit_code(u8 *ptr, u32 bytes, unsigned int len) |
0a14842f ED |
31 | { |
32 | if (len == 1) | |
33 | *ptr = bytes; | |
34 | else if (len == 2) | |
35 | *(u16 *)ptr = bytes; | |
36 | else { | |
37 | *(u32 *)ptr = bytes; | |
38 | barrier(); | |
39 | } | |
40 | return ptr + len; | |
41 | } | |
42 | ||
b52f00e6 AS |
43 | #define EMIT(bytes, len) \ |
44 | do { prog = emit_code(prog, bytes, len); cnt += len; } while (0) | |
0a14842f ED |
45 | |
46 | #define EMIT1(b1) EMIT(b1, 1) | |
47 | #define EMIT2(b1, b2) EMIT((b1) + ((b2) << 8), 2) | |
48 | #define EMIT3(b1, b2, b3) EMIT((b1) + ((b2) << 8) + ((b3) << 16), 3) | |
49 | #define EMIT4(b1, b2, b3, b4) EMIT((b1) + ((b2) << 8) + ((b3) << 16) + ((b4) << 24), 4) | |
62258278 AS |
50 | #define EMIT1_off32(b1, off) \ |
51 | do {EMIT1(b1); EMIT(off, 4); } while (0) | |
52 | #define EMIT2_off32(b1, b2, off) \ | |
53 | do {EMIT2(b1, b2); EMIT(off, 4); } while (0) | |
54 | #define EMIT3_off32(b1, b2, b3, off) \ | |
55 | do {EMIT3(b1, b2, b3); EMIT(off, 4); } while (0) | |
56 | #define EMIT4_off32(b1, b2, b3, b4, off) \ | |
57 | do {EMIT4(b1, b2, b3, b4); EMIT(off, 4); } while (0) | |
0a14842f | 58 | |
5cccc702 | 59 | static bool is_imm8(int value) |
0a14842f ED |
60 | { |
61 | return value <= 127 && value >= -128; | |
62 | } | |
63 | ||
5cccc702 | 64 | static bool is_simm32(s64 value) |
0a14842f | 65 | { |
62258278 | 66 | return value == (s64) (s32) value; |
0a14842f ED |
67 | } |
68 | ||
e430f34e AS |
69 | /* mov dst, src */ |
70 | #define EMIT_mov(DST, SRC) \ | |
71 | do {if (DST != SRC) \ | |
72 | EMIT3(add_2mod(0x48, DST, SRC), 0x89, add_2reg(0xC0, DST, SRC)); \ | |
62258278 AS |
73 | } while (0) |
74 | ||
75 | static int bpf_size_to_x86_bytes(int bpf_size) | |
76 | { | |
77 | if (bpf_size == BPF_W) | |
78 | return 4; | |
79 | else if (bpf_size == BPF_H) | |
80 | return 2; | |
81 | else if (bpf_size == BPF_B) | |
82 | return 1; | |
83 | else if (bpf_size == BPF_DW) | |
84 | return 4; /* imm32 */ | |
85 | else | |
86 | return 0; | |
87 | } | |
0a14842f ED |
88 | |
89 | /* list of x86 cond jumps opcodes (. + s8) | |
90 | * Add 0x10 (and an extra 0x0f) to generate far jumps (. + s32) | |
91 | */ | |
92 | #define X86_JB 0x72 | |
93 | #define X86_JAE 0x73 | |
94 | #define X86_JE 0x74 | |
95 | #define X86_JNE 0x75 | |
96 | #define X86_JBE 0x76 | |
97 | #define X86_JA 0x77 | |
52afc51e | 98 | #define X86_JL 0x7C |
62258278 | 99 | #define X86_JGE 0x7D |
52afc51e | 100 | #define X86_JLE 0x7E |
62258278 | 101 | #define X86_JG 0x7F |
0a14842f | 102 | |
5cccc702 | 103 | static void bpf_flush_icache(void *start, void *end) |
0a14842f ED |
104 | { |
105 | mm_segment_t old_fs = get_fs(); | |
106 | ||
107 | set_fs(KERNEL_DS); | |
108 | smp_wmb(); | |
109 | flush_icache_range((unsigned long)start, (unsigned long)end); | |
110 | set_fs(old_fs); | |
111 | } | |
112 | ||
a998d434 JS |
113 | #define CHOOSE_LOAD_FUNC(K, func) \ |
114 | ((int)K < 0 ? ((int)K >= SKF_LL_OFF ? func##_negative_offset : func) : func##_positive_offset) | |
0a14842f | 115 | |
62258278 | 116 | /* pick a register outside of BPF range for JIT internal work */ |
959a7579 | 117 | #define AUX_REG (MAX_BPF_JIT_REG + 1) |
62258278 | 118 | |
959a7579 DB |
119 | /* The following table maps BPF registers to x64 registers. |
120 | * | |
121 | * x64 register r12 is unused, since if used as base address | |
122 | * register in load/store instructions, it always needs an | |
123 | * extra byte of encoding and is callee saved. | |
124 | * | |
125 | * r9 caches skb->len - skb->data_len | |
126 | * r10 caches skb->data, and used for blinding (if enabled) | |
62258278 AS |
127 | */ |
128 | static const int reg2hex[] = { | |
129 | [BPF_REG_0] = 0, /* rax */ | |
130 | [BPF_REG_1] = 7, /* rdi */ | |
131 | [BPF_REG_2] = 6, /* rsi */ | |
132 | [BPF_REG_3] = 2, /* rdx */ | |
133 | [BPF_REG_4] = 1, /* rcx */ | |
134 | [BPF_REG_5] = 0, /* r8 */ | |
135 | [BPF_REG_6] = 3, /* rbx callee saved */ | |
136 | [BPF_REG_7] = 5, /* r13 callee saved */ | |
137 | [BPF_REG_8] = 6, /* r14 callee saved */ | |
138 | [BPF_REG_9] = 7, /* r15 callee saved */ | |
139 | [BPF_REG_FP] = 5, /* rbp readonly */ | |
959a7579 | 140 | [BPF_REG_AX] = 2, /* r10 temp register */ |
62258278 AS |
141 | [AUX_REG] = 3, /* r11 temp register */ |
142 | }; | |
143 | ||
144 | /* is_ereg() == true if BPF register 'reg' maps to x64 r8..r15 | |
145 | * which need extra byte of encoding. | |
146 | * rax,rcx,...,rbp have simpler encoding | |
147 | */ | |
5cccc702 | 148 | static bool is_ereg(u32 reg) |
62258278 | 149 | { |
d148134b JP |
150 | return (1 << reg) & (BIT(BPF_REG_5) | |
151 | BIT(AUX_REG) | | |
152 | BIT(BPF_REG_7) | | |
153 | BIT(BPF_REG_8) | | |
959a7579 DB |
154 | BIT(BPF_REG_9) | |
155 | BIT(BPF_REG_AX)); | |
62258278 AS |
156 | } |
157 | ||
158 | /* add modifiers if 'reg' maps to x64 registers r8..r15 */ | |
5cccc702 | 159 | static u8 add_1mod(u8 byte, u32 reg) |
62258278 AS |
160 | { |
161 | if (is_ereg(reg)) | |
162 | byte |= 1; | |
163 | return byte; | |
164 | } | |
165 | ||
5cccc702 | 166 | static u8 add_2mod(u8 byte, u32 r1, u32 r2) |
62258278 AS |
167 | { |
168 | if (is_ereg(r1)) | |
169 | byte |= 1; | |
170 | if (is_ereg(r2)) | |
171 | byte |= 4; | |
172 | return byte; | |
173 | } | |
174 | ||
e430f34e | 175 | /* encode 'dst_reg' register into x64 opcode 'byte' */ |
5cccc702 | 176 | static u8 add_1reg(u8 byte, u32 dst_reg) |
62258278 | 177 | { |
e430f34e | 178 | return byte + reg2hex[dst_reg]; |
62258278 AS |
179 | } |
180 | ||
e430f34e | 181 | /* encode 'dst_reg' and 'src_reg' registers into x64 opcode 'byte' */ |
5cccc702 | 182 | static u8 add_2reg(u8 byte, u32 dst_reg, u32 src_reg) |
62258278 | 183 | { |
e430f34e | 184 | return byte + reg2hex[dst_reg] + (reg2hex[src_reg] << 3); |
62258278 AS |
185 | } |
186 | ||
738cbe72 DB |
187 | static void jit_fill_hole(void *area, unsigned int size) |
188 | { | |
189 | /* fill whole space with int3 instructions */ | |
190 | memset(area, 0xcc, size); | |
191 | } | |
192 | ||
f3c2af7b | 193 | struct jit_context { |
769e0de6 | 194 | int cleanup_addr; /* epilogue code offset */ |
62258278 | 195 | bool seen_ld_abs; |
959a7579 | 196 | bool seen_ax_reg; |
f3c2af7b AS |
197 | }; |
198 | ||
e0ee9c12 AS |
199 | /* maximum number of bytes emitted while JITing one eBPF insn */ |
200 | #define BPF_MAX_INSN_SIZE 128 | |
201 | #define BPF_INSN_SAFETY 64 | |
202 | ||
177366bf AS |
203 | #define AUX_STACK_SPACE \ |
204 | (32 /* space for rbx, r13, r14, r15 */ + \ | |
b52f00e6 AS |
205 | 8 /* space for skb_copy_bits() buffer */) |
206 | ||
177366bf | 207 | #define PROLOGUE_SIZE 37 |
b52f00e6 AS |
208 | |
209 | /* emit x64 prologue code for BPF program and check it's size. | |
210 | * bpf_tail_call helper will skip it while jumping into another program | |
211 | */ | |
2960ae48 | 212 | static void emit_prologue(u8 **pprog, u32 stack_depth) |
0a14842f | 213 | { |
b52f00e6 AS |
214 | u8 *prog = *pprog; |
215 | int cnt = 0; | |
0a14842f | 216 | |
62258278 AS |
217 | EMIT1(0x55); /* push rbp */ |
218 | EMIT3(0x48, 0x89, 0xE5); /* mov rbp,rsp */ | |
0a14842f | 219 | |
2960ae48 AS |
220 | /* sub rsp, rounded_stack_depth + AUX_STACK_SPACE */ |
221 | EMIT3_off32(0x48, 0x81, 0xEC, | |
222 | round_up(stack_depth, 8) + AUX_STACK_SPACE); | |
177366bf AS |
223 | |
224 | /* sub rbp, AUX_STACK_SPACE */ | |
225 | EMIT4(0x48, 0x83, 0xED, AUX_STACK_SPACE); | |
62258278 AS |
226 | |
227 | /* all classic BPF filters use R6(rbx) save it */ | |
228 | ||
177366bf AS |
229 | /* mov qword ptr [rbp+0],rbx */ |
230 | EMIT4(0x48, 0x89, 0x5D, 0); | |
62258278 | 231 | |
8fb575ca | 232 | /* bpf_convert_filter() maps classic BPF register X to R7 and uses R8 |
62258278 AS |
233 | * as temporary, so all tcpdump filters need to spill/fill R7(r13) and |
234 | * R8(r14). R9(r15) spill could be made conditional, but there is only | |
235 | * one 'bpf_error' return path out of helper functions inside bpf_jit.S | |
236 | * The overhead of extra spill is negligible for any filter other | |
237 | * than synthetic ones. Therefore not worth adding complexity. | |
238 | */ | |
239 | ||
177366bf AS |
240 | /* mov qword ptr [rbp+8],r13 */ |
241 | EMIT4(0x4C, 0x89, 0x6D, 8); | |
242 | /* mov qword ptr [rbp+16],r14 */ | |
243 | EMIT4(0x4C, 0x89, 0x75, 16); | |
244 | /* mov qword ptr [rbp+24],r15 */ | |
245 | EMIT4(0x4C, 0x89, 0x7D, 24); | |
62258278 | 246 | |
8b614aeb DB |
247 | /* Clear the tail call counter (tail_call_cnt): for eBPF tail calls |
248 | * we need to reset the counter to 0. It's done in two instructions, | |
249 | * resetting rax register to 0 (xor on eax gets 0 extended), and | |
250 | * moving it to the counter location. | |
251 | */ | |
62258278 | 252 | |
8b614aeb DB |
253 | /* xor eax, eax */ |
254 | EMIT2(0x31, 0xc0); | |
177366bf AS |
255 | /* mov qword ptr [rbp+32], rax */ |
256 | EMIT4(0x48, 0x89, 0x45, 32); | |
b52f00e6 AS |
257 | |
258 | BUILD_BUG_ON(cnt != PROLOGUE_SIZE); | |
259 | *pprog = prog; | |
260 | } | |
261 | ||
262 | /* generate the following code: | |
263 | * ... bpf_tail_call(void *ctx, struct bpf_array *array, u64 index) ... | |
264 | * if (index >= array->map.max_entries) | |
265 | * goto out; | |
266 | * if (++tail_call_cnt > MAX_TAIL_CALL_CNT) | |
267 | * goto out; | |
2a36f0b9 | 268 | * prog = array->ptrs[index]; |
b52f00e6 AS |
269 | * if (prog == NULL) |
270 | * goto out; | |
271 | * goto *(prog->bpf_func + prologue_size); | |
272 | * out: | |
273 | */ | |
274 | static void emit_bpf_tail_call(u8 **pprog) | |
275 | { | |
276 | u8 *prog = *pprog; | |
277 | int label1, label2, label3; | |
278 | int cnt = 0; | |
279 | ||
280 | /* rdi - pointer to ctx | |
281 | * rsi - pointer to bpf_array | |
282 | * rdx - index in bpf_array | |
283 | */ | |
284 | ||
285 | /* if (index >= array->map.max_entries) | |
286 | * goto out; | |
287 | */ | |
90caccdd AS |
288 | EMIT2(0x89, 0xD2); /* mov edx, edx */ |
289 | EMIT3(0x39, 0x56, /* cmp dword ptr [rsi + 16], edx */ | |
b52f00e6 | 290 | offsetof(struct bpf_array, map.max_entries)); |
29fed5fa | 291 | #define OFFSET1 (41 + RETPOLINE_RAX_BPF_JIT_SIZE) /* number of bytes to jump */ |
b52f00e6 AS |
292 | EMIT2(X86_JBE, OFFSET1); /* jbe out */ |
293 | label1 = cnt; | |
294 | ||
295 | /* if (tail_call_cnt > MAX_TAIL_CALL_CNT) | |
296 | * goto out; | |
297 | */ | |
177366bf | 298 | EMIT2_off32(0x8B, 0x85, 36); /* mov eax, dword ptr [rbp + 36] */ |
b52f00e6 | 299 | EMIT3(0x83, 0xF8, MAX_TAIL_CALL_CNT); /* cmp eax, MAX_TAIL_CALL_CNT */ |
29fed5fa | 300 | #define OFFSET2 (30 + RETPOLINE_RAX_BPF_JIT_SIZE) |
b52f00e6 AS |
301 | EMIT2(X86_JA, OFFSET2); /* ja out */ |
302 | label2 = cnt; | |
303 | EMIT3(0x83, 0xC0, 0x01); /* add eax, 1 */ | |
177366bf | 304 | EMIT2_off32(0x89, 0x85, 36); /* mov dword ptr [rbp + 36], eax */ |
b52f00e6 | 305 | |
2a36f0b9 | 306 | /* prog = array->ptrs[index]; */ |
84ccac6e | 307 | EMIT4_off32(0x48, 0x8B, 0x84, 0xD6, /* mov rax, [rsi + rdx * 8 + offsetof(...)] */ |
2a36f0b9 | 308 | offsetof(struct bpf_array, ptrs)); |
b52f00e6 AS |
309 | |
310 | /* if (prog == NULL) | |
311 | * goto out; | |
312 | */ | |
84ccac6e | 313 | EMIT3(0x48, 0x85, 0xC0); /* test rax,rax */ |
29fed5fa | 314 | #define OFFSET3 (8 + RETPOLINE_RAX_BPF_JIT_SIZE) |
b52f00e6 AS |
315 | EMIT2(X86_JE, OFFSET3); /* je out */ |
316 | label3 = cnt; | |
317 | ||
318 | /* goto *(prog->bpf_func + prologue_size); */ | |
319 | EMIT4(0x48, 0x8B, 0x40, /* mov rax, qword ptr [rax + 32] */ | |
320 | offsetof(struct bpf_prog, bpf_func)); | |
321 | EMIT4(0x48, 0x83, 0xC0, PROLOGUE_SIZE); /* add rax, prologue_size */ | |
322 | ||
323 | /* now we're ready to jump into next BPF program | |
324 | * rdi == ctx (1st arg) | |
325 | * rax == prog->bpf_func + prologue_size | |
326 | */ | |
29fed5fa | 327 | RETPOLINE_RAX_BPF_JIT(); |
b52f00e6 AS |
328 | |
329 | /* out: */ | |
330 | BUILD_BUG_ON(cnt - label1 != OFFSET1); | |
331 | BUILD_BUG_ON(cnt - label2 != OFFSET2); | |
332 | BUILD_BUG_ON(cnt - label3 != OFFSET3); | |
333 | *pprog = prog; | |
334 | } | |
335 | ||
4e10df9a AS |
336 | |
337 | static void emit_load_skb_data_hlen(u8 **pprog) | |
338 | { | |
339 | u8 *prog = *pprog; | |
340 | int cnt = 0; | |
341 | ||
342 | /* r9d = skb->len - skb->data_len (headlen) | |
343 | * r10 = skb->data | |
344 | */ | |
345 | /* mov %r9d, off32(%rdi) */ | |
346 | EMIT3_off32(0x44, 0x8b, 0x8f, offsetof(struct sk_buff, len)); | |
347 | ||
348 | /* sub %r9d, off32(%rdi) */ | |
349 | EMIT3_off32(0x44, 0x2b, 0x8f, offsetof(struct sk_buff, data_len)); | |
350 | ||
351 | /* mov %r10, off32(%rdi) */ | |
352 | EMIT3_off32(0x4c, 0x8b, 0x97, offsetof(struct sk_buff, data)); | |
353 | *pprog = prog; | |
354 | } | |
355 | ||
b52f00e6 AS |
356 | static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image, |
357 | int oldproglen, struct jit_context *ctx) | |
358 | { | |
359 | struct bpf_insn *insn = bpf_prog->insnsi; | |
360 | int insn_cnt = bpf_prog->len; | |
361 | bool seen_ld_abs = ctx->seen_ld_abs | (oldproglen == 0); | |
959a7579 | 362 | bool seen_ax_reg = ctx->seen_ax_reg | (oldproglen == 0); |
b52f00e6 AS |
363 | bool seen_exit = false; |
364 | u8 temp[BPF_MAX_INSN_SIZE + BPF_INSN_SAFETY]; | |
365 | int i, cnt = 0; | |
366 | int proglen = 0; | |
367 | u8 *prog = temp; | |
368 | ||
2960ae48 | 369 | emit_prologue(&prog, bpf_prog->aux->stack_depth); |
b52f00e6 | 370 | |
4e10df9a AS |
371 | if (seen_ld_abs) |
372 | emit_load_skb_data_hlen(&prog); | |
62258278 AS |
373 | |
374 | for (i = 0; i < insn_cnt; i++, insn++) { | |
e430f34e AS |
375 | const s32 imm32 = insn->imm; |
376 | u32 dst_reg = insn->dst_reg; | |
377 | u32 src_reg = insn->src_reg; | |
62258278 AS |
378 | u8 b1 = 0, b2 = 0, b3 = 0; |
379 | s64 jmp_offset; | |
380 | u8 jmp_cond; | |
4e10df9a | 381 | bool reload_skb_data; |
62258278 AS |
382 | int ilen; |
383 | u8 *func; | |
384 | ||
959a7579 DB |
385 | if (dst_reg == BPF_REG_AX || src_reg == BPF_REG_AX) |
386 | ctx->seen_ax_reg = seen_ax_reg = true; | |
387 | ||
62258278 AS |
388 | switch (insn->code) { |
389 | /* ALU */ | |
390 | case BPF_ALU | BPF_ADD | BPF_X: | |
391 | case BPF_ALU | BPF_SUB | BPF_X: | |
392 | case BPF_ALU | BPF_AND | BPF_X: | |
393 | case BPF_ALU | BPF_OR | BPF_X: | |
394 | case BPF_ALU | BPF_XOR | BPF_X: | |
395 | case BPF_ALU64 | BPF_ADD | BPF_X: | |
396 | case BPF_ALU64 | BPF_SUB | BPF_X: | |
397 | case BPF_ALU64 | BPF_AND | BPF_X: | |
398 | case BPF_ALU64 | BPF_OR | BPF_X: | |
399 | case BPF_ALU64 | BPF_XOR | BPF_X: | |
400 | switch (BPF_OP(insn->code)) { | |
401 | case BPF_ADD: b2 = 0x01; break; | |
402 | case BPF_SUB: b2 = 0x29; break; | |
403 | case BPF_AND: b2 = 0x21; break; | |
404 | case BPF_OR: b2 = 0x09; break; | |
405 | case BPF_XOR: b2 = 0x31; break; | |
0a14842f | 406 | } |
62258278 | 407 | if (BPF_CLASS(insn->code) == BPF_ALU64) |
e430f34e AS |
408 | EMIT1(add_2mod(0x48, dst_reg, src_reg)); |
409 | else if (is_ereg(dst_reg) || is_ereg(src_reg)) | |
410 | EMIT1(add_2mod(0x40, dst_reg, src_reg)); | |
411 | EMIT2(b2, add_2reg(0xC0, dst_reg, src_reg)); | |
62258278 | 412 | break; |
0a14842f | 413 | |
e430f34e | 414 | /* mov dst, src */ |
62258278 | 415 | case BPF_ALU64 | BPF_MOV | BPF_X: |
e430f34e | 416 | EMIT_mov(dst_reg, src_reg); |
0a14842f | 417 | break; |
0a14842f | 418 | |
e430f34e | 419 | /* mov32 dst, src */ |
62258278 | 420 | case BPF_ALU | BPF_MOV | BPF_X: |
e430f34e AS |
421 | if (is_ereg(dst_reg) || is_ereg(src_reg)) |
422 | EMIT1(add_2mod(0x40, dst_reg, src_reg)); | |
423 | EMIT2(0x89, add_2reg(0xC0, dst_reg, src_reg)); | |
62258278 | 424 | break; |
0a14842f | 425 | |
e430f34e | 426 | /* neg dst */ |
62258278 AS |
427 | case BPF_ALU | BPF_NEG: |
428 | case BPF_ALU64 | BPF_NEG: | |
429 | if (BPF_CLASS(insn->code) == BPF_ALU64) | |
e430f34e AS |
430 | EMIT1(add_1mod(0x48, dst_reg)); |
431 | else if (is_ereg(dst_reg)) | |
432 | EMIT1(add_1mod(0x40, dst_reg)); | |
433 | EMIT2(0xF7, add_1reg(0xD8, dst_reg)); | |
62258278 AS |
434 | break; |
435 | ||
436 | case BPF_ALU | BPF_ADD | BPF_K: | |
437 | case BPF_ALU | BPF_SUB | BPF_K: | |
438 | case BPF_ALU | BPF_AND | BPF_K: | |
439 | case BPF_ALU | BPF_OR | BPF_K: | |
440 | case BPF_ALU | BPF_XOR | BPF_K: | |
441 | case BPF_ALU64 | BPF_ADD | BPF_K: | |
442 | case BPF_ALU64 | BPF_SUB | BPF_K: | |
443 | case BPF_ALU64 | BPF_AND | BPF_K: | |
444 | case BPF_ALU64 | BPF_OR | BPF_K: | |
445 | case BPF_ALU64 | BPF_XOR | BPF_K: | |
446 | if (BPF_CLASS(insn->code) == BPF_ALU64) | |
e430f34e AS |
447 | EMIT1(add_1mod(0x48, dst_reg)); |
448 | else if (is_ereg(dst_reg)) | |
449 | EMIT1(add_1mod(0x40, dst_reg)); | |
62258278 AS |
450 | |
451 | switch (BPF_OP(insn->code)) { | |
452 | case BPF_ADD: b3 = 0xC0; break; | |
453 | case BPF_SUB: b3 = 0xE8; break; | |
454 | case BPF_AND: b3 = 0xE0; break; | |
455 | case BPF_OR: b3 = 0xC8; break; | |
456 | case BPF_XOR: b3 = 0xF0; break; | |
457 | } | |
458 | ||
e430f34e AS |
459 | if (is_imm8(imm32)) |
460 | EMIT3(0x83, add_1reg(b3, dst_reg), imm32); | |
62258278 | 461 | else |
e430f34e | 462 | EMIT2_off32(0x81, add_1reg(b3, dst_reg), imm32); |
62258278 AS |
463 | break; |
464 | ||
465 | case BPF_ALU64 | BPF_MOV | BPF_K: | |
466 | /* optimization: if imm32 is positive, | |
467 | * use 'mov eax, imm32' (which zero-extends imm32) | |
468 | * to save 2 bytes | |
469 | */ | |
e430f34e | 470 | if (imm32 < 0) { |
62258278 | 471 | /* 'mov rax, imm32' sign extends imm32 */ |
e430f34e | 472 | b1 = add_1mod(0x48, dst_reg); |
62258278 AS |
473 | b2 = 0xC7; |
474 | b3 = 0xC0; | |
e430f34e | 475 | EMIT3_off32(b1, b2, add_1reg(b3, dst_reg), imm32); |
0a14842f | 476 | break; |
62258278 AS |
477 | } |
478 | ||
479 | case BPF_ALU | BPF_MOV | BPF_K: | |
606c88a8 DB |
480 | /* optimization: if imm32 is zero, use 'xor <dst>,<dst>' |
481 | * to save 3 bytes. | |
482 | */ | |
483 | if (imm32 == 0) { | |
484 | if (is_ereg(dst_reg)) | |
485 | EMIT1(add_2mod(0x40, dst_reg, dst_reg)); | |
486 | b2 = 0x31; /* xor */ | |
487 | b3 = 0xC0; | |
488 | EMIT2(b2, add_2reg(b3, dst_reg, dst_reg)); | |
489 | break; | |
490 | } | |
491 | ||
62258278 | 492 | /* mov %eax, imm32 */ |
e430f34e AS |
493 | if (is_ereg(dst_reg)) |
494 | EMIT1(add_1mod(0x40, dst_reg)); | |
495 | EMIT1_off32(add_1reg(0xB8, dst_reg), imm32); | |
62258278 AS |
496 | break; |
497 | ||
02ab695b | 498 | case BPF_LD | BPF_IMM | BPF_DW: |
606c88a8 DB |
499 | /* optimization: if imm64 is zero, use 'xor <dst>,<dst>' |
500 | * to save 7 bytes. | |
501 | */ | |
502 | if (insn[0].imm == 0 && insn[1].imm == 0) { | |
503 | b1 = add_2mod(0x48, dst_reg, dst_reg); | |
504 | b2 = 0x31; /* xor */ | |
505 | b3 = 0xC0; | |
506 | EMIT3(b1, b2, add_2reg(b3, dst_reg, dst_reg)); | |
507 | ||
508 | insn++; | |
509 | i++; | |
510 | break; | |
511 | } | |
512 | ||
02ab695b AS |
513 | /* movabsq %rax, imm64 */ |
514 | EMIT2(add_1mod(0x48, dst_reg), add_1reg(0xB8, dst_reg)); | |
515 | EMIT(insn[0].imm, 4); | |
516 | EMIT(insn[1].imm, 4); | |
517 | ||
518 | insn++; | |
519 | i++; | |
520 | break; | |
521 | ||
e430f34e | 522 | /* dst %= src, dst /= src, dst %= imm32, dst /= imm32 */ |
62258278 AS |
523 | case BPF_ALU | BPF_MOD | BPF_X: |
524 | case BPF_ALU | BPF_DIV | BPF_X: | |
525 | case BPF_ALU | BPF_MOD | BPF_K: | |
526 | case BPF_ALU | BPF_DIV | BPF_K: | |
527 | case BPF_ALU64 | BPF_MOD | BPF_X: | |
528 | case BPF_ALU64 | BPF_DIV | BPF_X: | |
529 | case BPF_ALU64 | BPF_MOD | BPF_K: | |
530 | case BPF_ALU64 | BPF_DIV | BPF_K: | |
531 | EMIT1(0x50); /* push rax */ | |
532 | EMIT1(0x52); /* push rdx */ | |
533 | ||
534 | if (BPF_SRC(insn->code) == BPF_X) | |
e430f34e AS |
535 | /* mov r11, src_reg */ |
536 | EMIT_mov(AUX_REG, src_reg); | |
62258278 | 537 | else |
e430f34e AS |
538 | /* mov r11, imm32 */ |
539 | EMIT3_off32(0x49, 0xC7, 0xC3, imm32); | |
62258278 | 540 | |
e430f34e AS |
541 | /* mov rax, dst_reg */ |
542 | EMIT_mov(BPF_REG_0, dst_reg); | |
62258278 AS |
543 | |
544 | /* xor edx, edx | |
545 | * equivalent to 'xor rdx, rdx', but one byte less | |
546 | */ | |
547 | EMIT2(0x31, 0xd2); | |
548 | ||
549 | if (BPF_SRC(insn->code) == BPF_X) { | |
e430f34e | 550 | /* if (src_reg == 0) return 0 */ |
62258278 AS |
551 | |
552 | /* cmp r11, 0 */ | |
553 | EMIT4(0x49, 0x83, 0xFB, 0x00); | |
554 | ||
555 | /* jne .+9 (skip over pop, pop, xor and jmp) */ | |
556 | EMIT2(X86_JNE, 1 + 1 + 2 + 5); | |
557 | EMIT1(0x5A); /* pop rdx */ | |
558 | EMIT1(0x58); /* pop rax */ | |
559 | EMIT2(0x31, 0xc0); /* xor eax, eax */ | |
560 | ||
561 | /* jmp cleanup_addr | |
562 | * addrs[i] - 11, because there are 11 bytes | |
563 | * after this insn: div, mov, pop, pop, mov | |
564 | */ | |
565 | jmp_offset = ctx->cleanup_addr - (addrs[i] - 11); | |
566 | EMIT1_off32(0xE9, jmp_offset); | |
567 | } | |
568 | ||
569 | if (BPF_CLASS(insn->code) == BPF_ALU64) | |
570 | /* div r11 */ | |
571 | EMIT3(0x49, 0xF7, 0xF3); | |
572 | else | |
573 | /* div r11d */ | |
574 | EMIT3(0x41, 0xF7, 0xF3); | |
575 | ||
576 | if (BPF_OP(insn->code) == BPF_MOD) | |
577 | /* mov r11, rdx */ | |
578 | EMIT3(0x49, 0x89, 0xD3); | |
579 | else | |
580 | /* mov r11, rax */ | |
581 | EMIT3(0x49, 0x89, 0xC3); | |
582 | ||
583 | EMIT1(0x5A); /* pop rdx */ | |
584 | EMIT1(0x58); /* pop rax */ | |
585 | ||
e430f34e AS |
586 | /* mov dst_reg, r11 */ |
587 | EMIT_mov(dst_reg, AUX_REG); | |
62258278 AS |
588 | break; |
589 | ||
590 | case BPF_ALU | BPF_MUL | BPF_K: | |
591 | case BPF_ALU | BPF_MUL | BPF_X: | |
592 | case BPF_ALU64 | BPF_MUL | BPF_K: | |
593 | case BPF_ALU64 | BPF_MUL | BPF_X: | |
594 | EMIT1(0x50); /* push rax */ | |
595 | EMIT1(0x52); /* push rdx */ | |
596 | ||
e430f34e AS |
597 | /* mov r11, dst_reg */ |
598 | EMIT_mov(AUX_REG, dst_reg); | |
62258278 AS |
599 | |
600 | if (BPF_SRC(insn->code) == BPF_X) | |
e430f34e AS |
601 | /* mov rax, src_reg */ |
602 | EMIT_mov(BPF_REG_0, src_reg); | |
62258278 | 603 | else |
e430f34e AS |
604 | /* mov rax, imm32 */ |
605 | EMIT3_off32(0x48, 0xC7, 0xC0, imm32); | |
62258278 AS |
606 | |
607 | if (BPF_CLASS(insn->code) == BPF_ALU64) | |
608 | EMIT1(add_1mod(0x48, AUX_REG)); | |
609 | else if (is_ereg(AUX_REG)) | |
610 | EMIT1(add_1mod(0x40, AUX_REG)); | |
611 | /* mul(q) r11 */ | |
612 | EMIT2(0xF7, add_1reg(0xE0, AUX_REG)); | |
613 | ||
614 | /* mov r11, rax */ | |
615 | EMIT_mov(AUX_REG, BPF_REG_0); | |
616 | ||
617 | EMIT1(0x5A); /* pop rdx */ | |
618 | EMIT1(0x58); /* pop rax */ | |
619 | ||
e430f34e AS |
620 | /* mov dst_reg, r11 */ |
621 | EMIT_mov(dst_reg, AUX_REG); | |
62258278 AS |
622 | break; |
623 | ||
624 | /* shifts */ | |
625 | case BPF_ALU | BPF_LSH | BPF_K: | |
626 | case BPF_ALU | BPF_RSH | BPF_K: | |
627 | case BPF_ALU | BPF_ARSH | BPF_K: | |
628 | case BPF_ALU64 | BPF_LSH | BPF_K: | |
629 | case BPF_ALU64 | BPF_RSH | BPF_K: | |
630 | case BPF_ALU64 | BPF_ARSH | BPF_K: | |
631 | if (BPF_CLASS(insn->code) == BPF_ALU64) | |
e430f34e AS |
632 | EMIT1(add_1mod(0x48, dst_reg)); |
633 | else if (is_ereg(dst_reg)) | |
634 | EMIT1(add_1mod(0x40, dst_reg)); | |
62258278 AS |
635 | |
636 | switch (BPF_OP(insn->code)) { | |
637 | case BPF_LSH: b3 = 0xE0; break; | |
638 | case BPF_RSH: b3 = 0xE8; break; | |
639 | case BPF_ARSH: b3 = 0xF8; break; | |
640 | } | |
e430f34e | 641 | EMIT3(0xC1, add_1reg(b3, dst_reg), imm32); |
62258278 AS |
642 | break; |
643 | ||
72b603ee AS |
644 | case BPF_ALU | BPF_LSH | BPF_X: |
645 | case BPF_ALU | BPF_RSH | BPF_X: | |
646 | case BPF_ALU | BPF_ARSH | BPF_X: | |
647 | case BPF_ALU64 | BPF_LSH | BPF_X: | |
648 | case BPF_ALU64 | BPF_RSH | BPF_X: | |
649 | case BPF_ALU64 | BPF_ARSH | BPF_X: | |
650 | ||
651 | /* check for bad case when dst_reg == rcx */ | |
652 | if (dst_reg == BPF_REG_4) { | |
653 | /* mov r11, dst_reg */ | |
654 | EMIT_mov(AUX_REG, dst_reg); | |
655 | dst_reg = AUX_REG; | |
656 | } | |
657 | ||
658 | if (src_reg != BPF_REG_4) { /* common case */ | |
659 | EMIT1(0x51); /* push rcx */ | |
660 | ||
661 | /* mov rcx, src_reg */ | |
662 | EMIT_mov(BPF_REG_4, src_reg); | |
663 | } | |
664 | ||
665 | /* shl %rax, %cl | shr %rax, %cl | sar %rax, %cl */ | |
666 | if (BPF_CLASS(insn->code) == BPF_ALU64) | |
667 | EMIT1(add_1mod(0x48, dst_reg)); | |
668 | else if (is_ereg(dst_reg)) | |
669 | EMIT1(add_1mod(0x40, dst_reg)); | |
670 | ||
671 | switch (BPF_OP(insn->code)) { | |
672 | case BPF_LSH: b3 = 0xE0; break; | |
673 | case BPF_RSH: b3 = 0xE8; break; | |
674 | case BPF_ARSH: b3 = 0xF8; break; | |
675 | } | |
676 | EMIT2(0xD3, add_1reg(b3, dst_reg)); | |
677 | ||
678 | if (src_reg != BPF_REG_4) | |
679 | EMIT1(0x59); /* pop rcx */ | |
680 | ||
681 | if (insn->dst_reg == BPF_REG_4) | |
682 | /* mov dst_reg, r11 */ | |
683 | EMIT_mov(insn->dst_reg, AUX_REG); | |
684 | break; | |
685 | ||
62258278 | 686 | case BPF_ALU | BPF_END | BPF_FROM_BE: |
e430f34e | 687 | switch (imm32) { |
62258278 AS |
688 | case 16: |
689 | /* emit 'ror %ax, 8' to swap lower 2 bytes */ | |
690 | EMIT1(0x66); | |
e430f34e | 691 | if (is_ereg(dst_reg)) |
62258278 | 692 | EMIT1(0x41); |
e430f34e | 693 | EMIT3(0xC1, add_1reg(0xC8, dst_reg), 8); |
343f845b AS |
694 | |
695 | /* emit 'movzwl eax, ax' */ | |
696 | if (is_ereg(dst_reg)) | |
697 | EMIT3(0x45, 0x0F, 0xB7); | |
698 | else | |
699 | EMIT2(0x0F, 0xB7); | |
700 | EMIT1(add_2reg(0xC0, dst_reg, dst_reg)); | |
62258278 AS |
701 | break; |
702 | case 32: | |
703 | /* emit 'bswap eax' to swap lower 4 bytes */ | |
e430f34e | 704 | if (is_ereg(dst_reg)) |
62258278 | 705 | EMIT2(0x41, 0x0F); |
0a14842f | 706 | else |
62258278 | 707 | EMIT1(0x0F); |
e430f34e | 708 | EMIT1(add_1reg(0xC8, dst_reg)); |
0a14842f | 709 | break; |
62258278 AS |
710 | case 64: |
711 | /* emit 'bswap rax' to swap 8 bytes */ | |
e430f34e AS |
712 | EMIT3(add_1mod(0x48, dst_reg), 0x0F, |
713 | add_1reg(0xC8, dst_reg)); | |
3b58908a ED |
714 | break; |
715 | } | |
62258278 AS |
716 | break; |
717 | ||
718 | case BPF_ALU | BPF_END | BPF_FROM_LE: | |
343f845b AS |
719 | switch (imm32) { |
720 | case 16: | |
721 | /* emit 'movzwl eax, ax' to zero extend 16-bit | |
722 | * into 64 bit | |
723 | */ | |
724 | if (is_ereg(dst_reg)) | |
725 | EMIT3(0x45, 0x0F, 0xB7); | |
726 | else | |
727 | EMIT2(0x0F, 0xB7); | |
728 | EMIT1(add_2reg(0xC0, dst_reg, dst_reg)); | |
729 | break; | |
730 | case 32: | |
731 | /* emit 'mov eax, eax' to clear upper 32-bits */ | |
732 | if (is_ereg(dst_reg)) | |
733 | EMIT1(0x45); | |
734 | EMIT2(0x89, add_2reg(0xC0, dst_reg, dst_reg)); | |
735 | break; | |
736 | case 64: | |
737 | /* nop */ | |
738 | break; | |
739 | } | |
62258278 AS |
740 | break; |
741 | ||
e430f34e | 742 | /* ST: *(u8*)(dst_reg + off) = imm */ |
62258278 | 743 | case BPF_ST | BPF_MEM | BPF_B: |
e430f34e | 744 | if (is_ereg(dst_reg)) |
62258278 AS |
745 | EMIT2(0x41, 0xC6); |
746 | else | |
747 | EMIT1(0xC6); | |
748 | goto st; | |
749 | case BPF_ST | BPF_MEM | BPF_H: | |
e430f34e | 750 | if (is_ereg(dst_reg)) |
62258278 AS |
751 | EMIT3(0x66, 0x41, 0xC7); |
752 | else | |
753 | EMIT2(0x66, 0xC7); | |
754 | goto st; | |
755 | case BPF_ST | BPF_MEM | BPF_W: | |
e430f34e | 756 | if (is_ereg(dst_reg)) |
62258278 AS |
757 | EMIT2(0x41, 0xC7); |
758 | else | |
759 | EMIT1(0xC7); | |
760 | goto st; | |
761 | case BPF_ST | BPF_MEM | BPF_DW: | |
e430f34e | 762 | EMIT2(add_1mod(0x48, dst_reg), 0xC7); |
62258278 AS |
763 | |
764 | st: if (is_imm8(insn->off)) | |
e430f34e | 765 | EMIT2(add_1reg(0x40, dst_reg), insn->off); |
62258278 | 766 | else |
e430f34e | 767 | EMIT1_off32(add_1reg(0x80, dst_reg), insn->off); |
62258278 | 768 | |
e430f34e | 769 | EMIT(imm32, bpf_size_to_x86_bytes(BPF_SIZE(insn->code))); |
62258278 AS |
770 | break; |
771 | ||
e430f34e | 772 | /* STX: *(u8*)(dst_reg + off) = src_reg */ |
62258278 AS |
773 | case BPF_STX | BPF_MEM | BPF_B: |
774 | /* emit 'mov byte ptr [rax + off], al' */ | |
e430f34e | 775 | if (is_ereg(dst_reg) || is_ereg(src_reg) || |
62258278 | 776 | /* have to add extra byte for x86 SIL, DIL regs */ |
e430f34e AS |
777 | src_reg == BPF_REG_1 || src_reg == BPF_REG_2) |
778 | EMIT2(add_2mod(0x40, dst_reg, src_reg), 0x88); | |
62258278 AS |
779 | else |
780 | EMIT1(0x88); | |
781 | goto stx; | |
782 | case BPF_STX | BPF_MEM | BPF_H: | |
e430f34e AS |
783 | if (is_ereg(dst_reg) || is_ereg(src_reg)) |
784 | EMIT3(0x66, add_2mod(0x40, dst_reg, src_reg), 0x89); | |
62258278 AS |
785 | else |
786 | EMIT2(0x66, 0x89); | |
787 | goto stx; | |
788 | case BPF_STX | BPF_MEM | BPF_W: | |
e430f34e AS |
789 | if (is_ereg(dst_reg) || is_ereg(src_reg)) |
790 | EMIT2(add_2mod(0x40, dst_reg, src_reg), 0x89); | |
62258278 AS |
791 | else |
792 | EMIT1(0x89); | |
793 | goto stx; | |
794 | case BPF_STX | BPF_MEM | BPF_DW: | |
e430f34e | 795 | EMIT2(add_2mod(0x48, dst_reg, src_reg), 0x89); |
62258278 | 796 | stx: if (is_imm8(insn->off)) |
e430f34e | 797 | EMIT2(add_2reg(0x40, dst_reg, src_reg), insn->off); |
62258278 | 798 | else |
e430f34e | 799 | EMIT1_off32(add_2reg(0x80, dst_reg, src_reg), |
62258278 AS |
800 | insn->off); |
801 | break; | |
802 | ||
e430f34e | 803 | /* LDX: dst_reg = *(u8*)(src_reg + off) */ |
62258278 AS |
804 | case BPF_LDX | BPF_MEM | BPF_B: |
805 | /* emit 'movzx rax, byte ptr [rax + off]' */ | |
e430f34e | 806 | EMIT3(add_2mod(0x48, src_reg, dst_reg), 0x0F, 0xB6); |
62258278 AS |
807 | goto ldx; |
808 | case BPF_LDX | BPF_MEM | BPF_H: | |
809 | /* emit 'movzx rax, word ptr [rax + off]' */ | |
e430f34e | 810 | EMIT3(add_2mod(0x48, src_reg, dst_reg), 0x0F, 0xB7); |
62258278 AS |
811 | goto ldx; |
812 | case BPF_LDX | BPF_MEM | BPF_W: | |
813 | /* emit 'mov eax, dword ptr [rax+0x14]' */ | |
e430f34e AS |
814 | if (is_ereg(dst_reg) || is_ereg(src_reg)) |
815 | EMIT2(add_2mod(0x40, src_reg, dst_reg), 0x8B); | |
62258278 AS |
816 | else |
817 | EMIT1(0x8B); | |
818 | goto ldx; | |
819 | case BPF_LDX | BPF_MEM | BPF_DW: | |
820 | /* emit 'mov rax, qword ptr [rax+0x14]' */ | |
e430f34e | 821 | EMIT2(add_2mod(0x48, src_reg, dst_reg), 0x8B); |
62258278 AS |
822 | ldx: /* if insn->off == 0 we can save one extra byte, but |
823 | * special case of x86 r13 which always needs an offset | |
824 | * is not worth the hassle | |
825 | */ | |
826 | if (is_imm8(insn->off)) | |
e430f34e | 827 | EMIT2(add_2reg(0x40, src_reg, dst_reg), insn->off); |
62258278 | 828 | else |
e430f34e | 829 | EMIT1_off32(add_2reg(0x80, src_reg, dst_reg), |
62258278 AS |
830 | insn->off); |
831 | break; | |
832 | ||
e430f34e | 833 | /* STX XADD: lock *(u32*)(dst_reg + off) += src_reg */ |
62258278 AS |
834 | case BPF_STX | BPF_XADD | BPF_W: |
835 | /* emit 'lock add dword ptr [rax + off], eax' */ | |
e430f34e AS |
836 | if (is_ereg(dst_reg) || is_ereg(src_reg)) |
837 | EMIT3(0xF0, add_2mod(0x40, dst_reg, src_reg), 0x01); | |
62258278 AS |
838 | else |
839 | EMIT2(0xF0, 0x01); | |
840 | goto xadd; | |
841 | case BPF_STX | BPF_XADD | BPF_DW: | |
e430f34e | 842 | EMIT3(0xF0, add_2mod(0x48, dst_reg, src_reg), 0x01); |
62258278 | 843 | xadd: if (is_imm8(insn->off)) |
e430f34e | 844 | EMIT2(add_2reg(0x40, dst_reg, src_reg), insn->off); |
62258278 | 845 | else |
e430f34e | 846 | EMIT1_off32(add_2reg(0x80, dst_reg, src_reg), |
62258278 AS |
847 | insn->off); |
848 | break; | |
849 | ||
850 | /* call */ | |
851 | case BPF_JMP | BPF_CALL: | |
e430f34e | 852 | func = (u8 *) __bpf_call_base + imm32; |
62258278 | 853 | jmp_offset = func - (image + addrs[i]); |
e0ee9c12 | 854 | if (seen_ld_abs) { |
17bedab2 | 855 | reload_skb_data = bpf_helper_changes_pkt_data(func); |
4e10df9a AS |
856 | if (reload_skb_data) { |
857 | EMIT1(0x57); /* push %rdi */ | |
858 | jmp_offset += 22; /* pop, mov, sub, mov */ | |
859 | } else { | |
860 | EMIT2(0x41, 0x52); /* push %r10 */ | |
861 | EMIT2(0x41, 0x51); /* push %r9 */ | |
862 | /* need to adjust jmp offset, since | |
863 | * pop %r9, pop %r10 take 4 bytes after call insn | |
864 | */ | |
865 | jmp_offset += 4; | |
866 | } | |
62258278 | 867 | } |
e430f34e | 868 | if (!imm32 || !is_simm32(jmp_offset)) { |
62258278 | 869 | pr_err("unsupported bpf func %d addr %p image %p\n", |
e430f34e | 870 | imm32, func, image); |
62258278 AS |
871 | return -EINVAL; |
872 | } | |
873 | EMIT1_off32(0xE8, jmp_offset); | |
e0ee9c12 | 874 | if (seen_ld_abs) { |
4e10df9a AS |
875 | if (reload_skb_data) { |
876 | EMIT1(0x5F); /* pop %rdi */ | |
877 | emit_load_skb_data_hlen(&prog); | |
878 | } else { | |
879 | EMIT2(0x41, 0x59); /* pop %r9 */ | |
880 | EMIT2(0x41, 0x5A); /* pop %r10 */ | |
881 | } | |
62258278 AS |
882 | } |
883 | break; | |
884 | ||
71189fa9 | 885 | case BPF_JMP | BPF_TAIL_CALL: |
b52f00e6 AS |
886 | emit_bpf_tail_call(&prog); |
887 | break; | |
888 | ||
62258278 AS |
889 | /* cond jump */ |
890 | case BPF_JMP | BPF_JEQ | BPF_X: | |
891 | case BPF_JMP | BPF_JNE | BPF_X: | |
892 | case BPF_JMP | BPF_JGT | BPF_X: | |
52afc51e | 893 | case BPF_JMP | BPF_JLT | BPF_X: |
62258278 | 894 | case BPF_JMP | BPF_JGE | BPF_X: |
52afc51e | 895 | case BPF_JMP | BPF_JLE | BPF_X: |
62258278 | 896 | case BPF_JMP | BPF_JSGT | BPF_X: |
52afc51e | 897 | case BPF_JMP | BPF_JSLT | BPF_X: |
62258278 | 898 | case BPF_JMP | BPF_JSGE | BPF_X: |
52afc51e | 899 | case BPF_JMP | BPF_JSLE | BPF_X: |
e430f34e AS |
900 | /* cmp dst_reg, src_reg */ |
901 | EMIT3(add_2mod(0x48, dst_reg, src_reg), 0x39, | |
902 | add_2reg(0xC0, dst_reg, src_reg)); | |
62258278 AS |
903 | goto emit_cond_jmp; |
904 | ||
905 | case BPF_JMP | BPF_JSET | BPF_X: | |
e430f34e AS |
906 | /* test dst_reg, src_reg */ |
907 | EMIT3(add_2mod(0x48, dst_reg, src_reg), 0x85, | |
908 | add_2reg(0xC0, dst_reg, src_reg)); | |
62258278 AS |
909 | goto emit_cond_jmp; |
910 | ||
911 | case BPF_JMP | BPF_JSET | BPF_K: | |
e430f34e AS |
912 | /* test dst_reg, imm32 */ |
913 | EMIT1(add_1mod(0x48, dst_reg)); | |
914 | EMIT2_off32(0xF7, add_1reg(0xC0, dst_reg), imm32); | |
62258278 AS |
915 | goto emit_cond_jmp; |
916 | ||
917 | case BPF_JMP | BPF_JEQ | BPF_K: | |
918 | case BPF_JMP | BPF_JNE | BPF_K: | |
919 | case BPF_JMP | BPF_JGT | BPF_K: | |
52afc51e | 920 | case BPF_JMP | BPF_JLT | BPF_K: |
62258278 | 921 | case BPF_JMP | BPF_JGE | BPF_K: |
52afc51e | 922 | case BPF_JMP | BPF_JLE | BPF_K: |
62258278 | 923 | case BPF_JMP | BPF_JSGT | BPF_K: |
52afc51e | 924 | case BPF_JMP | BPF_JSLT | BPF_K: |
62258278 | 925 | case BPF_JMP | BPF_JSGE | BPF_K: |
52afc51e | 926 | case BPF_JMP | BPF_JSLE | BPF_K: |
e430f34e AS |
927 | /* cmp dst_reg, imm8/32 */ |
928 | EMIT1(add_1mod(0x48, dst_reg)); | |
62258278 | 929 | |
e430f34e AS |
930 | if (is_imm8(imm32)) |
931 | EMIT3(0x83, add_1reg(0xF8, dst_reg), imm32); | |
62258278 | 932 | else |
e430f34e | 933 | EMIT2_off32(0x81, add_1reg(0xF8, dst_reg), imm32); |
62258278 AS |
934 | |
935 | emit_cond_jmp: /* convert BPF opcode to x86 */ | |
936 | switch (BPF_OP(insn->code)) { | |
937 | case BPF_JEQ: | |
938 | jmp_cond = X86_JE; | |
939 | break; | |
940 | case BPF_JSET: | |
941 | case BPF_JNE: | |
942 | jmp_cond = X86_JNE; | |
943 | break; | |
944 | case BPF_JGT: | |
945 | /* GT is unsigned '>', JA in x86 */ | |
946 | jmp_cond = X86_JA; | |
947 | break; | |
52afc51e DB |
948 | case BPF_JLT: |
949 | /* LT is unsigned '<', JB in x86 */ | |
950 | jmp_cond = X86_JB; | |
951 | break; | |
62258278 AS |
952 | case BPF_JGE: |
953 | /* GE is unsigned '>=', JAE in x86 */ | |
954 | jmp_cond = X86_JAE; | |
955 | break; | |
52afc51e DB |
956 | case BPF_JLE: |
957 | /* LE is unsigned '<=', JBE in x86 */ | |
958 | jmp_cond = X86_JBE; | |
959 | break; | |
62258278 AS |
960 | case BPF_JSGT: |
961 | /* signed '>', GT in x86 */ | |
962 | jmp_cond = X86_JG; | |
963 | break; | |
52afc51e DB |
964 | case BPF_JSLT: |
965 | /* signed '<', LT in x86 */ | |
966 | jmp_cond = X86_JL; | |
967 | break; | |
62258278 AS |
968 | case BPF_JSGE: |
969 | /* signed '>=', GE in x86 */ | |
970 | jmp_cond = X86_JGE; | |
971 | break; | |
52afc51e DB |
972 | case BPF_JSLE: |
973 | /* signed '<=', LE in x86 */ | |
974 | jmp_cond = X86_JLE; | |
975 | break; | |
62258278 AS |
976 | default: /* to silence gcc warning */ |
977 | return -EFAULT; | |
978 | } | |
979 | jmp_offset = addrs[i + insn->off] - addrs[i]; | |
980 | if (is_imm8(jmp_offset)) { | |
981 | EMIT2(jmp_cond, jmp_offset); | |
982 | } else if (is_simm32(jmp_offset)) { | |
983 | EMIT2_off32(0x0F, jmp_cond + 0x10, jmp_offset); | |
984 | } else { | |
985 | pr_err("cond_jmp gen bug %llx\n", jmp_offset); | |
986 | return -EFAULT; | |
987 | } | |
988 | ||
989 | break; | |
0a14842f | 990 | |
62258278 | 991 | case BPF_JMP | BPF_JA: |
368e5325 GB |
992 | if (insn->off == -1) |
993 | /* -1 jmp instructions will always jump | |
994 | * backwards two bytes. Explicitly handling | |
995 | * this case avoids wasting too many passes | |
996 | * when there are long sequences of replaced | |
997 | * dead code. | |
998 | */ | |
999 | jmp_offset = -2; | |
1000 | else | |
1001 | jmp_offset = addrs[i + insn->off] - addrs[i]; | |
1002 | ||
62258278 AS |
1003 | if (!jmp_offset) |
1004 | /* optimize out nop jumps */ | |
1005 | break; | |
1006 | emit_jmp: | |
1007 | if (is_imm8(jmp_offset)) { | |
1008 | EMIT2(0xEB, jmp_offset); | |
1009 | } else if (is_simm32(jmp_offset)) { | |
1010 | EMIT1_off32(0xE9, jmp_offset); | |
1011 | } else { | |
1012 | pr_err("jmp gen bug %llx\n", jmp_offset); | |
1013 | return -EFAULT; | |
1014 | } | |
1015 | break; | |
1016 | ||
1017 | case BPF_LD | BPF_IND | BPF_W: | |
1018 | func = sk_load_word; | |
1019 | goto common_load; | |
1020 | case BPF_LD | BPF_ABS | BPF_W: | |
e430f34e | 1021 | func = CHOOSE_LOAD_FUNC(imm32, sk_load_word); |
e0ee9c12 AS |
1022 | common_load: |
1023 | ctx->seen_ld_abs = seen_ld_abs = true; | |
62258278 AS |
1024 | jmp_offset = func - (image + addrs[i]); |
1025 | if (!func || !is_simm32(jmp_offset)) { | |
1026 | pr_err("unsupported bpf func %d addr %p image %p\n", | |
e430f34e | 1027 | imm32, func, image); |
62258278 AS |
1028 | return -EINVAL; |
1029 | } | |
1030 | if (BPF_MODE(insn->code) == BPF_ABS) { | |
1031 | /* mov %esi, imm32 */ | |
e430f34e | 1032 | EMIT1_off32(0xBE, imm32); |
62258278 | 1033 | } else { |
e430f34e AS |
1034 | /* mov %rsi, src_reg */ |
1035 | EMIT_mov(BPF_REG_2, src_reg); | |
1036 | if (imm32) { | |
1037 | if (is_imm8(imm32)) | |
62258278 | 1038 | /* add %esi, imm8 */ |
e430f34e | 1039 | EMIT3(0x83, 0xC6, imm32); |
0a14842f | 1040 | else |
62258278 | 1041 | /* add %esi, imm32 */ |
e430f34e | 1042 | EMIT2_off32(0x81, 0xC6, imm32); |
0a14842f | 1043 | } |
62258278 AS |
1044 | } |
1045 | /* skb pointer is in R6 (%rbx), it will be copied into | |
1046 | * %rdi if skb_copy_bits() call is necessary. | |
1047 | * sk_load_* helpers also use %r10 and %r9d. | |
1048 | * See bpf_jit.S | |
1049 | */ | |
959a7579 DB |
1050 | if (seen_ax_reg) |
1051 | /* r10 = skb->data, mov %r10, off32(%rbx) */ | |
1052 | EMIT3_off32(0x4c, 0x8b, 0x93, | |
1053 | offsetof(struct sk_buff, data)); | |
62258278 AS |
1054 | EMIT1_off32(0xE8, jmp_offset); /* call */ |
1055 | break; | |
1056 | ||
1057 | case BPF_LD | BPF_IND | BPF_H: | |
1058 | func = sk_load_half; | |
1059 | goto common_load; | |
1060 | case BPF_LD | BPF_ABS | BPF_H: | |
e430f34e | 1061 | func = CHOOSE_LOAD_FUNC(imm32, sk_load_half); |
62258278 AS |
1062 | goto common_load; |
1063 | case BPF_LD | BPF_IND | BPF_B: | |
1064 | func = sk_load_byte; | |
1065 | goto common_load; | |
1066 | case BPF_LD | BPF_ABS | BPF_B: | |
e430f34e | 1067 | func = CHOOSE_LOAD_FUNC(imm32, sk_load_byte); |
62258278 AS |
1068 | goto common_load; |
1069 | ||
1070 | case BPF_JMP | BPF_EXIT: | |
769e0de6 | 1071 | if (seen_exit) { |
62258278 AS |
1072 | jmp_offset = ctx->cleanup_addr - addrs[i]; |
1073 | goto emit_jmp; | |
1074 | } | |
769e0de6 | 1075 | seen_exit = true; |
62258278 AS |
1076 | /* update cleanup_addr */ |
1077 | ctx->cleanup_addr = proglen; | |
177366bf AS |
1078 | /* mov rbx, qword ptr [rbp+0] */ |
1079 | EMIT4(0x48, 0x8B, 0x5D, 0); | |
1080 | /* mov r13, qword ptr [rbp+8] */ | |
1081 | EMIT4(0x4C, 0x8B, 0x6D, 8); | |
1082 | /* mov r14, qword ptr [rbp+16] */ | |
1083 | EMIT4(0x4C, 0x8B, 0x75, 16); | |
1084 | /* mov r15, qword ptr [rbp+24] */ | |
1085 | EMIT4(0x4C, 0x8B, 0x7D, 24); | |
1086 | ||
1087 | /* add rbp, AUX_STACK_SPACE */ | |
1088 | EMIT4(0x48, 0x83, 0xC5, AUX_STACK_SPACE); | |
62258278 AS |
1089 | EMIT1(0xC9); /* leave */ |
1090 | EMIT1(0xC3); /* ret */ | |
1091 | break; | |
1092 | ||
f3c2af7b | 1093 | default: |
62258278 AS |
1094 | /* By design x64 JIT should support all BPF instructions |
1095 | * This error will be seen if new instruction was added | |
1096 | * to interpreter, but not to JIT | |
7ae457c1 | 1097 | * or if there is junk in bpf_prog |
62258278 AS |
1098 | */ |
1099 | pr_err("bpf_jit: unknown opcode %02x\n", insn->code); | |
f3c2af7b AS |
1100 | return -EINVAL; |
1101 | } | |
62258278 | 1102 | |
f3c2af7b | 1103 | ilen = prog - temp; |
e0ee9c12 | 1104 | if (ilen > BPF_MAX_INSN_SIZE) { |
9383191d | 1105 | pr_err("bpf_jit: fatal insn size error\n"); |
e0ee9c12 AS |
1106 | return -EFAULT; |
1107 | } | |
1108 | ||
f3c2af7b AS |
1109 | if (image) { |
1110 | if (unlikely(proglen + ilen > oldproglen)) { | |
9383191d | 1111 | pr_err("bpf_jit: fatal error\n"); |
f3c2af7b | 1112 | return -EFAULT; |
0a14842f | 1113 | } |
f3c2af7b | 1114 | memcpy(image + proglen, temp, ilen); |
0a14842f | 1115 | } |
f3c2af7b AS |
1116 | proglen += ilen; |
1117 | addrs[i] = proglen; | |
1118 | prog = temp; | |
1119 | } | |
f3c2af7b AS |
1120 | return proglen; |
1121 | } | |
1122 | ||
d1c55ab5 | 1123 | struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog) |
f3c2af7b AS |
1124 | { |
1125 | struct bpf_binary_header *header = NULL; | |
959a7579 | 1126 | struct bpf_prog *tmp, *orig_prog = prog; |
f3c2af7b AS |
1127 | int proglen, oldproglen = 0; |
1128 | struct jit_context ctx = {}; | |
959a7579 | 1129 | bool tmp_blinded = false; |
f3c2af7b AS |
1130 | u8 *image = NULL; |
1131 | int *addrs; | |
1132 | int pass; | |
1133 | int i; | |
1134 | ||
1135 | if (!bpf_jit_enable) | |
959a7579 DB |
1136 | return orig_prog; |
1137 | ||
1138 | tmp = bpf_jit_blind_constants(prog); | |
1139 | /* If blinding was requested and we failed during blinding, | |
1140 | * we must fall back to the interpreter. | |
1141 | */ | |
1142 | if (IS_ERR(tmp)) | |
1143 | return orig_prog; | |
1144 | if (tmp != prog) { | |
1145 | tmp_blinded = true; | |
1146 | prog = tmp; | |
1147 | } | |
0a14842f | 1148 | |
f3c2af7b | 1149 | addrs = kmalloc(prog->len * sizeof(*addrs), GFP_KERNEL); |
959a7579 DB |
1150 | if (!addrs) { |
1151 | prog = orig_prog; | |
1152 | goto out; | |
1153 | } | |
f3c2af7b AS |
1154 | |
1155 | /* Before first pass, make a rough estimation of addrs[] | |
1156 | * each bpf instruction is translated to less than 64 bytes | |
1157 | */ | |
1158 | for (proglen = 0, i = 0; i < prog->len; i++) { | |
1159 | proglen += 64; | |
1160 | addrs[i] = proglen; | |
1161 | } | |
1162 | ctx.cleanup_addr = proglen; | |
f3c2af7b | 1163 | |
3f7352bf AS |
1164 | /* JITed image shrinks with every pass and the loop iterates |
1165 | * until the image stops shrinking. Very large bpf programs | |
1166 | * may converge on the last pass. In such case do one more | |
1167 | * pass to emit the final image | |
1168 | */ | |
ddccb957 | 1169 | for (pass = 0; pass < 20 || image; pass++) { |
f3c2af7b AS |
1170 | proglen = do_jit(prog, addrs, image, oldproglen, &ctx); |
1171 | if (proglen <= 0) { | |
7aa3b8f7 | 1172 | out_image: |
f3c2af7b AS |
1173 | image = NULL; |
1174 | if (header) | |
738cbe72 | 1175 | bpf_jit_binary_free(header); |
959a7579 DB |
1176 | prog = orig_prog; |
1177 | goto out_addrs; | |
f3c2af7b | 1178 | } |
0a14842f | 1179 | if (image) { |
e0ee9c12 | 1180 | if (proglen != oldproglen) { |
f3c2af7b AS |
1181 | pr_err("bpf_jit: proglen=%d != oldproglen=%d\n", |
1182 | proglen, oldproglen); | |
7aa3b8f7 | 1183 | goto out_image; |
e0ee9c12 | 1184 | } |
0a14842f ED |
1185 | break; |
1186 | } | |
1187 | if (proglen == oldproglen) { | |
738cbe72 DB |
1188 | header = bpf_jit_binary_alloc(proglen, &image, |
1189 | 1, jit_fill_hole); | |
959a7579 DB |
1190 | if (!header) { |
1191 | prog = orig_prog; | |
1192 | goto out_addrs; | |
1193 | } | |
0a14842f ED |
1194 | } |
1195 | oldproglen = proglen; | |
ddccb957 | 1196 | cond_resched(); |
0a14842f | 1197 | } |
79617801 | 1198 | |
0a14842f | 1199 | if (bpf_jit_enable > 1) |
485d6511 | 1200 | bpf_jit_dump(prog->len, proglen, pass + 1, image); |
0a14842f ED |
1201 | |
1202 | if (image) { | |
314beb9b | 1203 | bpf_flush_icache(header, image + proglen); |
9d876e79 | 1204 | bpf_jit_binary_lock_ro(header); |
f3c2af7b | 1205 | prog->bpf_func = (void *)image; |
a91263d5 | 1206 | prog->jited = 1; |
783d28dd | 1207 | prog->jited_len = proglen; |
9d5ecb09 DB |
1208 | } else { |
1209 | prog = orig_prog; | |
0a14842f | 1210 | } |
959a7579 DB |
1211 | |
1212 | out_addrs: | |
0a14842f | 1213 | kfree(addrs); |
959a7579 DB |
1214 | out: |
1215 | if (tmp_blinded) | |
1216 | bpf_jit_prog_release_other(prog, prog == orig_prog ? | |
1217 | tmp : orig_prog); | |
d1c55ab5 | 1218 | return prog; |
0a14842f | 1219 | } |