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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 | { |
6fe8b9c1 DB |
63 | return value == (s64)(s32)value; |
64 | } | |
65 | ||
66 | static bool is_uimm32(u64 value) | |
67 | { | |
68 | return value == (u64)(u32)value; | |
0a14842f ED |
69 | } |
70 | ||
e430f34e AS |
71 | /* mov dst, src */ |
72 | #define EMIT_mov(DST, SRC) \ | |
73 | do {if (DST != SRC) \ | |
74 | EMIT3(add_2mod(0x48, DST, SRC), 0x89, add_2reg(0xC0, DST, SRC)); \ | |
62258278 AS |
75 | } while (0) |
76 | ||
77 | static int bpf_size_to_x86_bytes(int bpf_size) | |
78 | { | |
79 | if (bpf_size == BPF_W) | |
80 | return 4; | |
81 | else if (bpf_size == BPF_H) | |
82 | return 2; | |
83 | else if (bpf_size == BPF_B) | |
84 | return 1; | |
85 | else if (bpf_size == BPF_DW) | |
86 | return 4; /* imm32 */ | |
87 | else | |
88 | return 0; | |
89 | } | |
0a14842f ED |
90 | |
91 | /* list of x86 cond jumps opcodes (. + s8) | |
92 | * Add 0x10 (and an extra 0x0f) to generate far jumps (. + s32) | |
93 | */ | |
94 | #define X86_JB 0x72 | |
95 | #define X86_JAE 0x73 | |
96 | #define X86_JE 0x74 | |
97 | #define X86_JNE 0x75 | |
98 | #define X86_JBE 0x76 | |
99 | #define X86_JA 0x77 | |
52afc51e | 100 | #define X86_JL 0x7C |
62258278 | 101 | #define X86_JGE 0x7D |
52afc51e | 102 | #define X86_JLE 0x7E |
62258278 | 103 | #define X86_JG 0x7F |
0a14842f | 104 | |
5cccc702 | 105 | static void bpf_flush_icache(void *start, void *end) |
0a14842f ED |
106 | { |
107 | mm_segment_t old_fs = get_fs(); | |
108 | ||
109 | set_fs(KERNEL_DS); | |
110 | smp_wmb(); | |
111 | flush_icache_range((unsigned long)start, (unsigned long)end); | |
112 | set_fs(old_fs); | |
113 | } | |
114 | ||
a998d434 JS |
115 | #define CHOOSE_LOAD_FUNC(K, func) \ |
116 | ((int)K < 0 ? ((int)K >= SKF_LL_OFF ? func##_negative_offset : func) : func##_positive_offset) | |
0a14842f | 117 | |
62258278 | 118 | /* pick a register outside of BPF range for JIT internal work */ |
959a7579 | 119 | #define AUX_REG (MAX_BPF_JIT_REG + 1) |
62258278 | 120 | |
959a7579 DB |
121 | /* The following table maps BPF registers to x64 registers. |
122 | * | |
123 | * x64 register r12 is unused, since if used as base address | |
124 | * register in load/store instructions, it always needs an | |
125 | * extra byte of encoding and is callee saved. | |
126 | * | |
127 | * r9 caches skb->len - skb->data_len | |
128 | * r10 caches skb->data, and used for blinding (if enabled) | |
62258278 AS |
129 | */ |
130 | static const int reg2hex[] = { | |
131 | [BPF_REG_0] = 0, /* rax */ | |
132 | [BPF_REG_1] = 7, /* rdi */ | |
133 | [BPF_REG_2] = 6, /* rsi */ | |
134 | [BPF_REG_3] = 2, /* rdx */ | |
135 | [BPF_REG_4] = 1, /* rcx */ | |
136 | [BPF_REG_5] = 0, /* r8 */ | |
137 | [BPF_REG_6] = 3, /* rbx callee saved */ | |
138 | [BPF_REG_7] = 5, /* r13 callee saved */ | |
139 | [BPF_REG_8] = 6, /* r14 callee saved */ | |
140 | [BPF_REG_9] = 7, /* r15 callee saved */ | |
141 | [BPF_REG_FP] = 5, /* rbp readonly */ | |
959a7579 | 142 | [BPF_REG_AX] = 2, /* r10 temp register */ |
62258278 AS |
143 | [AUX_REG] = 3, /* r11 temp register */ |
144 | }; | |
145 | ||
146 | /* is_ereg() == true if BPF register 'reg' maps to x64 r8..r15 | |
147 | * which need extra byte of encoding. | |
148 | * rax,rcx,...,rbp have simpler encoding | |
149 | */ | |
5cccc702 | 150 | static bool is_ereg(u32 reg) |
62258278 | 151 | { |
d148134b JP |
152 | return (1 << reg) & (BIT(BPF_REG_5) | |
153 | BIT(AUX_REG) | | |
154 | BIT(BPF_REG_7) | | |
155 | BIT(BPF_REG_8) | | |
959a7579 DB |
156 | BIT(BPF_REG_9) | |
157 | BIT(BPF_REG_AX)); | |
62258278 AS |
158 | } |
159 | ||
de0a444d DB |
160 | static bool is_axreg(u32 reg) |
161 | { | |
162 | return reg == BPF_REG_0; | |
163 | } | |
164 | ||
62258278 | 165 | /* add modifiers if 'reg' maps to x64 registers r8..r15 */ |
5cccc702 | 166 | static u8 add_1mod(u8 byte, u32 reg) |
62258278 AS |
167 | { |
168 | if (is_ereg(reg)) | |
169 | byte |= 1; | |
170 | return byte; | |
171 | } | |
172 | ||
5cccc702 | 173 | static u8 add_2mod(u8 byte, u32 r1, u32 r2) |
62258278 AS |
174 | { |
175 | if (is_ereg(r1)) | |
176 | byte |= 1; | |
177 | if (is_ereg(r2)) | |
178 | byte |= 4; | |
179 | return byte; | |
180 | } | |
181 | ||
e430f34e | 182 | /* encode 'dst_reg' register into x64 opcode 'byte' */ |
5cccc702 | 183 | static u8 add_1reg(u8 byte, u32 dst_reg) |
62258278 | 184 | { |
e430f34e | 185 | return byte + reg2hex[dst_reg]; |
62258278 AS |
186 | } |
187 | ||
e430f34e | 188 | /* encode 'dst_reg' and 'src_reg' registers into x64 opcode 'byte' */ |
5cccc702 | 189 | static u8 add_2reg(u8 byte, u32 dst_reg, u32 src_reg) |
62258278 | 190 | { |
e430f34e | 191 | return byte + reg2hex[dst_reg] + (reg2hex[src_reg] << 3); |
62258278 AS |
192 | } |
193 | ||
738cbe72 DB |
194 | static void jit_fill_hole(void *area, unsigned int size) |
195 | { | |
196 | /* fill whole space with int3 instructions */ | |
197 | memset(area, 0xcc, size); | |
198 | } | |
199 | ||
f3c2af7b | 200 | struct jit_context { |
769e0de6 | 201 | int cleanup_addr; /* epilogue code offset */ |
62258278 | 202 | bool seen_ld_abs; |
959a7579 | 203 | bool seen_ax_reg; |
f3c2af7b AS |
204 | }; |
205 | ||
e0ee9c12 AS |
206 | /* maximum number of bytes emitted while JITing one eBPF insn */ |
207 | #define BPF_MAX_INSN_SIZE 128 | |
208 | #define BPF_INSN_SAFETY 64 | |
209 | ||
177366bf AS |
210 | #define AUX_STACK_SPACE \ |
211 | (32 /* space for rbx, r13, r14, r15 */ + \ | |
b52f00e6 AS |
212 | 8 /* space for skb_copy_bits() buffer */) |
213 | ||
177366bf | 214 | #define PROLOGUE_SIZE 37 |
b52f00e6 AS |
215 | |
216 | /* emit x64 prologue code for BPF program and check it's size. | |
217 | * bpf_tail_call helper will skip it while jumping into another program | |
218 | */ | |
2960ae48 | 219 | static void emit_prologue(u8 **pprog, u32 stack_depth) |
0a14842f | 220 | { |
b52f00e6 AS |
221 | u8 *prog = *pprog; |
222 | int cnt = 0; | |
0a14842f | 223 | |
62258278 AS |
224 | EMIT1(0x55); /* push rbp */ |
225 | EMIT3(0x48, 0x89, 0xE5); /* mov rbp,rsp */ | |
0a14842f | 226 | |
2960ae48 AS |
227 | /* sub rsp, rounded_stack_depth + AUX_STACK_SPACE */ |
228 | EMIT3_off32(0x48, 0x81, 0xEC, | |
229 | round_up(stack_depth, 8) + AUX_STACK_SPACE); | |
177366bf AS |
230 | |
231 | /* sub rbp, AUX_STACK_SPACE */ | |
232 | EMIT4(0x48, 0x83, 0xED, AUX_STACK_SPACE); | |
62258278 AS |
233 | |
234 | /* all classic BPF filters use R6(rbx) save it */ | |
235 | ||
177366bf AS |
236 | /* mov qword ptr [rbp+0],rbx */ |
237 | EMIT4(0x48, 0x89, 0x5D, 0); | |
62258278 | 238 | |
8fb575ca | 239 | /* bpf_convert_filter() maps classic BPF register X to R7 and uses R8 |
62258278 AS |
240 | * as temporary, so all tcpdump filters need to spill/fill R7(r13) and |
241 | * R8(r14). R9(r15) spill could be made conditional, but there is only | |
242 | * one 'bpf_error' return path out of helper functions inside bpf_jit.S | |
243 | * The overhead of extra spill is negligible for any filter other | |
244 | * than synthetic ones. Therefore not worth adding complexity. | |
245 | */ | |
246 | ||
177366bf AS |
247 | /* mov qword ptr [rbp+8],r13 */ |
248 | EMIT4(0x4C, 0x89, 0x6D, 8); | |
249 | /* mov qword ptr [rbp+16],r14 */ | |
250 | EMIT4(0x4C, 0x89, 0x75, 16); | |
251 | /* mov qword ptr [rbp+24],r15 */ | |
252 | EMIT4(0x4C, 0x89, 0x7D, 24); | |
62258278 | 253 | |
8b614aeb DB |
254 | /* Clear the tail call counter (tail_call_cnt): for eBPF tail calls |
255 | * we need to reset the counter to 0. It's done in two instructions, | |
256 | * resetting rax register to 0 (xor on eax gets 0 extended), and | |
257 | * moving it to the counter location. | |
258 | */ | |
62258278 | 259 | |
8b614aeb DB |
260 | /* xor eax, eax */ |
261 | EMIT2(0x31, 0xc0); | |
177366bf AS |
262 | /* mov qword ptr [rbp+32], rax */ |
263 | EMIT4(0x48, 0x89, 0x45, 32); | |
b52f00e6 AS |
264 | |
265 | BUILD_BUG_ON(cnt != PROLOGUE_SIZE); | |
266 | *pprog = prog; | |
267 | } | |
268 | ||
269 | /* generate the following code: | |
270 | * ... bpf_tail_call(void *ctx, struct bpf_array *array, u64 index) ... | |
271 | * if (index >= array->map.max_entries) | |
272 | * goto out; | |
273 | * if (++tail_call_cnt > MAX_TAIL_CALL_CNT) | |
274 | * goto out; | |
2a36f0b9 | 275 | * prog = array->ptrs[index]; |
b52f00e6 AS |
276 | * if (prog == NULL) |
277 | * goto out; | |
278 | * goto *(prog->bpf_func + prologue_size); | |
279 | * out: | |
280 | */ | |
281 | static void emit_bpf_tail_call(u8 **pprog) | |
282 | { | |
283 | u8 *prog = *pprog; | |
284 | int label1, label2, label3; | |
285 | int cnt = 0; | |
286 | ||
287 | /* rdi - pointer to ctx | |
288 | * rsi - pointer to bpf_array | |
289 | * rdx - index in bpf_array | |
290 | */ | |
291 | ||
292 | /* if (index >= array->map.max_entries) | |
293 | * goto out; | |
294 | */ | |
90caccdd AS |
295 | EMIT2(0x89, 0xD2); /* mov edx, edx */ |
296 | EMIT3(0x39, 0x56, /* cmp dword ptr [rsi + 16], edx */ | |
b52f00e6 | 297 | offsetof(struct bpf_array, map.max_entries)); |
84ccac6e | 298 | #define OFFSET1 43 /* number of bytes to jump */ |
b52f00e6 AS |
299 | EMIT2(X86_JBE, OFFSET1); /* jbe out */ |
300 | label1 = cnt; | |
301 | ||
302 | /* if (tail_call_cnt > MAX_TAIL_CALL_CNT) | |
303 | * goto out; | |
304 | */ | |
177366bf | 305 | EMIT2_off32(0x8B, 0x85, 36); /* mov eax, dword ptr [rbp + 36] */ |
b52f00e6 | 306 | EMIT3(0x83, 0xF8, MAX_TAIL_CALL_CNT); /* cmp eax, MAX_TAIL_CALL_CNT */ |
84ccac6e | 307 | #define OFFSET2 32 |
b52f00e6 AS |
308 | EMIT2(X86_JA, OFFSET2); /* ja out */ |
309 | label2 = cnt; | |
310 | EMIT3(0x83, 0xC0, 0x01); /* add eax, 1 */ | |
177366bf | 311 | EMIT2_off32(0x89, 0x85, 36); /* mov dword ptr [rbp + 36], eax */ |
b52f00e6 | 312 | |
2a36f0b9 | 313 | /* prog = array->ptrs[index]; */ |
84ccac6e | 314 | EMIT4_off32(0x48, 0x8B, 0x84, 0xD6, /* mov rax, [rsi + rdx * 8 + offsetof(...)] */ |
2a36f0b9 | 315 | offsetof(struct bpf_array, ptrs)); |
b52f00e6 AS |
316 | |
317 | /* if (prog == NULL) | |
318 | * goto out; | |
319 | */ | |
84ccac6e | 320 | EMIT3(0x48, 0x85, 0xC0); /* test rax,rax */ |
b52f00e6 AS |
321 | #define OFFSET3 10 |
322 | EMIT2(X86_JE, OFFSET3); /* je out */ | |
323 | label3 = cnt; | |
324 | ||
325 | /* goto *(prog->bpf_func + prologue_size); */ | |
326 | EMIT4(0x48, 0x8B, 0x40, /* mov rax, qword ptr [rax + 32] */ | |
327 | offsetof(struct bpf_prog, bpf_func)); | |
328 | EMIT4(0x48, 0x83, 0xC0, PROLOGUE_SIZE); /* add rax, prologue_size */ | |
329 | ||
330 | /* now we're ready to jump into next BPF program | |
331 | * rdi == ctx (1st arg) | |
332 | * rax == prog->bpf_func + prologue_size | |
333 | */ | |
334 | EMIT2(0xFF, 0xE0); /* jmp rax */ | |
335 | ||
336 | /* out: */ | |
337 | BUILD_BUG_ON(cnt - label1 != OFFSET1); | |
338 | BUILD_BUG_ON(cnt - label2 != OFFSET2); | |
339 | BUILD_BUG_ON(cnt - label3 != OFFSET3); | |
340 | *pprog = prog; | |
341 | } | |
342 | ||
4e10df9a AS |
343 | |
344 | static void emit_load_skb_data_hlen(u8 **pprog) | |
345 | { | |
346 | u8 *prog = *pprog; | |
347 | int cnt = 0; | |
348 | ||
349 | /* r9d = skb->len - skb->data_len (headlen) | |
350 | * r10 = skb->data | |
351 | */ | |
352 | /* mov %r9d, off32(%rdi) */ | |
353 | EMIT3_off32(0x44, 0x8b, 0x8f, offsetof(struct sk_buff, len)); | |
354 | ||
355 | /* sub %r9d, off32(%rdi) */ | |
356 | EMIT3_off32(0x44, 0x2b, 0x8f, offsetof(struct sk_buff, data_len)); | |
357 | ||
358 | /* mov %r10, off32(%rdi) */ | |
359 | EMIT3_off32(0x4c, 0x8b, 0x97, offsetof(struct sk_buff, data)); | |
360 | *pprog = prog; | |
361 | } | |
362 | ||
6fe8b9c1 DB |
363 | static void emit_mov_imm32(u8 **pprog, bool sign_propagate, |
364 | u32 dst_reg, const u32 imm32) | |
365 | { | |
366 | u8 *prog = *pprog; | |
367 | u8 b1, b2, b3; | |
368 | int cnt = 0; | |
369 | ||
370 | /* optimization: if imm32 is positive, use 'mov %eax, imm32' | |
371 | * (which zero-extends imm32) to save 2 bytes. | |
372 | */ | |
373 | if (sign_propagate && (s32)imm32 < 0) { | |
374 | /* 'mov %rax, imm32' sign extends imm32 */ | |
375 | b1 = add_1mod(0x48, dst_reg); | |
376 | b2 = 0xC7; | |
377 | b3 = 0xC0; | |
378 | EMIT3_off32(b1, b2, add_1reg(b3, dst_reg), imm32); | |
379 | goto done; | |
380 | } | |
381 | ||
382 | /* optimization: if imm32 is zero, use 'xor %eax, %eax' | |
383 | * to save 3 bytes. | |
384 | */ | |
385 | if (imm32 == 0) { | |
386 | if (is_ereg(dst_reg)) | |
387 | EMIT1(add_2mod(0x40, dst_reg, dst_reg)); | |
388 | b2 = 0x31; /* xor */ | |
389 | b3 = 0xC0; | |
390 | EMIT2(b2, add_2reg(b3, dst_reg, dst_reg)); | |
391 | goto done; | |
392 | } | |
393 | ||
394 | /* mov %eax, imm32 */ | |
395 | if (is_ereg(dst_reg)) | |
396 | EMIT1(add_1mod(0x40, dst_reg)); | |
397 | EMIT1_off32(add_1reg(0xB8, dst_reg), imm32); | |
398 | done: | |
399 | *pprog = prog; | |
400 | } | |
401 | ||
402 | static void emit_mov_imm64(u8 **pprog, u32 dst_reg, | |
403 | const u32 imm32_hi, const u32 imm32_lo) | |
404 | { | |
405 | u8 *prog = *pprog; | |
406 | int cnt = 0; | |
407 | ||
408 | if (is_uimm32(((u64)imm32_hi << 32) | (u32)imm32_lo)) { | |
409 | /* For emitting plain u32, where sign bit must not be | |
410 | * propagated LLVM tends to load imm64 over mov32 | |
411 | * directly, so save couple of bytes by just doing | |
412 | * 'mov %eax, imm32' instead. | |
413 | */ | |
414 | emit_mov_imm32(&prog, false, dst_reg, imm32_lo); | |
415 | } else { | |
416 | /* movabsq %rax, imm64 */ | |
417 | EMIT2(add_1mod(0x48, dst_reg), add_1reg(0xB8, dst_reg)); | |
418 | EMIT(imm32_lo, 4); | |
419 | EMIT(imm32_hi, 4); | |
420 | } | |
421 | ||
422 | *pprog = prog; | |
423 | } | |
424 | ||
4c38e2f3 DB |
425 | static void emit_mov_reg(u8 **pprog, bool is64, u32 dst_reg, u32 src_reg) |
426 | { | |
427 | u8 *prog = *pprog; | |
428 | int cnt = 0; | |
429 | ||
430 | if (is64) { | |
431 | /* mov dst, src */ | |
432 | EMIT_mov(dst_reg, src_reg); | |
433 | } else { | |
434 | /* mov32 dst, src */ | |
435 | if (is_ereg(dst_reg) || is_ereg(src_reg)) | |
436 | EMIT1(add_2mod(0x40, dst_reg, src_reg)); | |
437 | EMIT2(0x89, add_2reg(0xC0, dst_reg, src_reg)); | |
438 | } | |
439 | ||
440 | *pprog = prog; | |
441 | } | |
442 | ||
b52f00e6 AS |
443 | static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image, |
444 | int oldproglen, struct jit_context *ctx) | |
445 | { | |
446 | struct bpf_insn *insn = bpf_prog->insnsi; | |
447 | int insn_cnt = bpf_prog->len; | |
448 | bool seen_ld_abs = ctx->seen_ld_abs | (oldproglen == 0); | |
959a7579 | 449 | bool seen_ax_reg = ctx->seen_ax_reg | (oldproglen == 0); |
b52f00e6 AS |
450 | bool seen_exit = false; |
451 | u8 temp[BPF_MAX_INSN_SIZE + BPF_INSN_SAFETY]; | |
452 | int i, cnt = 0; | |
453 | int proglen = 0; | |
454 | u8 *prog = temp; | |
455 | ||
2960ae48 | 456 | emit_prologue(&prog, bpf_prog->aux->stack_depth); |
b52f00e6 | 457 | |
4e10df9a AS |
458 | if (seen_ld_abs) |
459 | emit_load_skb_data_hlen(&prog); | |
62258278 AS |
460 | |
461 | for (i = 0; i < insn_cnt; i++, insn++) { | |
e430f34e AS |
462 | const s32 imm32 = insn->imm; |
463 | u32 dst_reg = insn->dst_reg; | |
464 | u32 src_reg = insn->src_reg; | |
6fe8b9c1 | 465 | u8 b2 = 0, b3 = 0; |
62258278 AS |
466 | s64 jmp_offset; |
467 | u8 jmp_cond; | |
4e10df9a | 468 | bool reload_skb_data; |
62258278 AS |
469 | int ilen; |
470 | u8 *func; | |
471 | ||
959a7579 DB |
472 | if (dst_reg == BPF_REG_AX || src_reg == BPF_REG_AX) |
473 | ctx->seen_ax_reg = seen_ax_reg = true; | |
474 | ||
62258278 AS |
475 | switch (insn->code) { |
476 | /* ALU */ | |
477 | case BPF_ALU | BPF_ADD | BPF_X: | |
478 | case BPF_ALU | BPF_SUB | BPF_X: | |
479 | case BPF_ALU | BPF_AND | BPF_X: | |
480 | case BPF_ALU | BPF_OR | BPF_X: | |
481 | case BPF_ALU | BPF_XOR | BPF_X: | |
482 | case BPF_ALU64 | BPF_ADD | BPF_X: | |
483 | case BPF_ALU64 | BPF_SUB | BPF_X: | |
484 | case BPF_ALU64 | BPF_AND | BPF_X: | |
485 | case BPF_ALU64 | BPF_OR | BPF_X: | |
486 | case BPF_ALU64 | BPF_XOR | BPF_X: | |
487 | switch (BPF_OP(insn->code)) { | |
488 | case BPF_ADD: b2 = 0x01; break; | |
489 | case BPF_SUB: b2 = 0x29; break; | |
490 | case BPF_AND: b2 = 0x21; break; | |
491 | case BPF_OR: b2 = 0x09; break; | |
492 | case BPF_XOR: b2 = 0x31; break; | |
0a14842f | 493 | } |
62258278 | 494 | if (BPF_CLASS(insn->code) == BPF_ALU64) |
e430f34e AS |
495 | EMIT1(add_2mod(0x48, dst_reg, src_reg)); |
496 | else if (is_ereg(dst_reg) || is_ereg(src_reg)) | |
497 | EMIT1(add_2mod(0x40, dst_reg, src_reg)); | |
498 | EMIT2(b2, add_2reg(0xC0, dst_reg, src_reg)); | |
62258278 | 499 | break; |
0a14842f | 500 | |
62258278 | 501 | case BPF_ALU64 | BPF_MOV | BPF_X: |
62258278 | 502 | case BPF_ALU | BPF_MOV | BPF_X: |
4c38e2f3 DB |
503 | emit_mov_reg(&prog, |
504 | BPF_CLASS(insn->code) == BPF_ALU64, | |
505 | dst_reg, src_reg); | |
62258278 | 506 | break; |
0a14842f | 507 | |
e430f34e | 508 | /* neg dst */ |
62258278 AS |
509 | case BPF_ALU | BPF_NEG: |
510 | case BPF_ALU64 | BPF_NEG: | |
511 | if (BPF_CLASS(insn->code) == BPF_ALU64) | |
e430f34e AS |
512 | EMIT1(add_1mod(0x48, dst_reg)); |
513 | else if (is_ereg(dst_reg)) | |
514 | EMIT1(add_1mod(0x40, dst_reg)); | |
515 | EMIT2(0xF7, add_1reg(0xD8, dst_reg)); | |
62258278 AS |
516 | break; |
517 | ||
518 | case BPF_ALU | BPF_ADD | BPF_K: | |
519 | case BPF_ALU | BPF_SUB | BPF_K: | |
520 | case BPF_ALU | BPF_AND | BPF_K: | |
521 | case BPF_ALU | BPF_OR | BPF_K: | |
522 | case BPF_ALU | BPF_XOR | BPF_K: | |
523 | case BPF_ALU64 | BPF_ADD | BPF_K: | |
524 | case BPF_ALU64 | BPF_SUB | BPF_K: | |
525 | case BPF_ALU64 | BPF_AND | BPF_K: | |
526 | case BPF_ALU64 | BPF_OR | BPF_K: | |
527 | case BPF_ALU64 | BPF_XOR | BPF_K: | |
528 | if (BPF_CLASS(insn->code) == BPF_ALU64) | |
e430f34e AS |
529 | EMIT1(add_1mod(0x48, dst_reg)); |
530 | else if (is_ereg(dst_reg)) | |
531 | EMIT1(add_1mod(0x40, dst_reg)); | |
62258278 | 532 | |
de0a444d DB |
533 | /* b3 holds 'normal' opcode, b2 short form only valid |
534 | * in case dst is eax/rax. | |
535 | */ | |
62258278 | 536 | switch (BPF_OP(insn->code)) { |
de0a444d DB |
537 | case BPF_ADD: |
538 | b3 = 0xC0; | |
539 | b2 = 0x05; | |
540 | break; | |
541 | case BPF_SUB: | |
542 | b3 = 0xE8; | |
543 | b2 = 0x2D; | |
544 | break; | |
545 | case BPF_AND: | |
546 | b3 = 0xE0; | |
547 | b2 = 0x25; | |
548 | break; | |
549 | case BPF_OR: | |
550 | b3 = 0xC8; | |
551 | b2 = 0x0D; | |
552 | break; | |
553 | case BPF_XOR: | |
554 | b3 = 0xF0; | |
555 | b2 = 0x35; | |
556 | break; | |
62258278 AS |
557 | } |
558 | ||
e430f34e AS |
559 | if (is_imm8(imm32)) |
560 | EMIT3(0x83, add_1reg(b3, dst_reg), imm32); | |
de0a444d DB |
561 | else if (is_axreg(dst_reg)) |
562 | EMIT1_off32(b2, imm32); | |
62258278 | 563 | else |
e430f34e | 564 | EMIT2_off32(0x81, add_1reg(b3, dst_reg), imm32); |
62258278 AS |
565 | break; |
566 | ||
567 | case BPF_ALU64 | BPF_MOV | BPF_K: | |
62258278 | 568 | case BPF_ALU | BPF_MOV | BPF_K: |
6fe8b9c1 DB |
569 | emit_mov_imm32(&prog, BPF_CLASS(insn->code) == BPF_ALU64, |
570 | dst_reg, imm32); | |
62258278 AS |
571 | break; |
572 | ||
02ab695b | 573 | case BPF_LD | BPF_IMM | BPF_DW: |
6fe8b9c1 | 574 | emit_mov_imm64(&prog, dst_reg, insn[1].imm, insn[0].imm); |
02ab695b AS |
575 | insn++; |
576 | i++; | |
577 | break; | |
578 | ||
e430f34e | 579 | /* dst %= src, dst /= src, dst %= imm32, dst /= imm32 */ |
62258278 AS |
580 | case BPF_ALU | BPF_MOD | BPF_X: |
581 | case BPF_ALU | BPF_DIV | BPF_X: | |
582 | case BPF_ALU | BPF_MOD | BPF_K: | |
583 | case BPF_ALU | BPF_DIV | BPF_K: | |
584 | case BPF_ALU64 | BPF_MOD | BPF_X: | |
585 | case BPF_ALU64 | BPF_DIV | BPF_X: | |
586 | case BPF_ALU64 | BPF_MOD | BPF_K: | |
587 | case BPF_ALU64 | BPF_DIV | BPF_K: | |
588 | EMIT1(0x50); /* push rax */ | |
589 | EMIT1(0x52); /* push rdx */ | |
590 | ||
591 | if (BPF_SRC(insn->code) == BPF_X) | |
e430f34e AS |
592 | /* mov r11, src_reg */ |
593 | EMIT_mov(AUX_REG, src_reg); | |
62258278 | 594 | else |
e430f34e AS |
595 | /* mov r11, imm32 */ |
596 | EMIT3_off32(0x49, 0xC7, 0xC3, imm32); | |
62258278 | 597 | |
e430f34e AS |
598 | /* mov rax, dst_reg */ |
599 | EMIT_mov(BPF_REG_0, dst_reg); | |
62258278 AS |
600 | |
601 | /* xor edx, edx | |
602 | * equivalent to 'xor rdx, rdx', but one byte less | |
603 | */ | |
604 | EMIT2(0x31, 0xd2); | |
605 | ||
62258278 AS |
606 | if (BPF_CLASS(insn->code) == BPF_ALU64) |
607 | /* div r11 */ | |
608 | EMIT3(0x49, 0xF7, 0xF3); | |
609 | else | |
610 | /* div r11d */ | |
611 | EMIT3(0x41, 0xF7, 0xF3); | |
612 | ||
613 | if (BPF_OP(insn->code) == BPF_MOD) | |
614 | /* mov r11, rdx */ | |
615 | EMIT3(0x49, 0x89, 0xD3); | |
616 | else | |
617 | /* mov r11, rax */ | |
618 | EMIT3(0x49, 0x89, 0xC3); | |
619 | ||
620 | EMIT1(0x5A); /* pop rdx */ | |
621 | EMIT1(0x58); /* pop rax */ | |
622 | ||
e430f34e AS |
623 | /* mov dst_reg, r11 */ |
624 | EMIT_mov(dst_reg, AUX_REG); | |
62258278 AS |
625 | break; |
626 | ||
627 | case BPF_ALU | BPF_MUL | BPF_K: | |
628 | case BPF_ALU | BPF_MUL | BPF_X: | |
629 | case BPF_ALU64 | BPF_MUL | BPF_K: | |
630 | case BPF_ALU64 | BPF_MUL | BPF_X: | |
4c38e2f3 DB |
631 | { |
632 | bool is64 = BPF_CLASS(insn->code) == BPF_ALU64; | |
633 | ||
d806a0cf DB |
634 | if (dst_reg != BPF_REG_0) |
635 | EMIT1(0x50); /* push rax */ | |
636 | if (dst_reg != BPF_REG_3) | |
637 | EMIT1(0x52); /* push rdx */ | |
62258278 | 638 | |
e430f34e AS |
639 | /* mov r11, dst_reg */ |
640 | EMIT_mov(AUX_REG, dst_reg); | |
62258278 AS |
641 | |
642 | if (BPF_SRC(insn->code) == BPF_X) | |
4c38e2f3 | 643 | emit_mov_reg(&prog, is64, BPF_REG_0, src_reg); |
62258278 | 644 | else |
4c38e2f3 | 645 | emit_mov_imm32(&prog, is64, BPF_REG_0, imm32); |
62258278 | 646 | |
4c38e2f3 | 647 | if (is64) |
62258278 AS |
648 | EMIT1(add_1mod(0x48, AUX_REG)); |
649 | else if (is_ereg(AUX_REG)) | |
650 | EMIT1(add_1mod(0x40, AUX_REG)); | |
651 | /* mul(q) r11 */ | |
652 | EMIT2(0xF7, add_1reg(0xE0, AUX_REG)); | |
653 | ||
d806a0cf DB |
654 | if (dst_reg != BPF_REG_3) |
655 | EMIT1(0x5A); /* pop rdx */ | |
656 | if (dst_reg != BPF_REG_0) { | |
657 | /* mov dst_reg, rax */ | |
658 | EMIT_mov(dst_reg, BPF_REG_0); | |
659 | EMIT1(0x58); /* pop rax */ | |
660 | } | |
62258278 | 661 | break; |
4c38e2f3 | 662 | } |
62258278 AS |
663 | /* shifts */ |
664 | case BPF_ALU | BPF_LSH | BPF_K: | |
665 | case BPF_ALU | BPF_RSH | BPF_K: | |
666 | case BPF_ALU | BPF_ARSH | BPF_K: | |
667 | case BPF_ALU64 | BPF_LSH | BPF_K: | |
668 | case BPF_ALU64 | BPF_RSH | BPF_K: | |
669 | case BPF_ALU64 | BPF_ARSH | BPF_K: | |
670 | if (BPF_CLASS(insn->code) == BPF_ALU64) | |
e430f34e AS |
671 | EMIT1(add_1mod(0x48, dst_reg)); |
672 | else if (is_ereg(dst_reg)) | |
673 | EMIT1(add_1mod(0x40, dst_reg)); | |
62258278 AS |
674 | |
675 | switch (BPF_OP(insn->code)) { | |
676 | case BPF_LSH: b3 = 0xE0; break; | |
677 | case BPF_RSH: b3 = 0xE8; break; | |
678 | case BPF_ARSH: b3 = 0xF8; break; | |
679 | } | |
88e69a1f DB |
680 | |
681 | if (imm32 == 1) | |
682 | EMIT2(0xD1, add_1reg(b3, dst_reg)); | |
683 | else | |
684 | EMIT3(0xC1, add_1reg(b3, dst_reg), imm32); | |
62258278 AS |
685 | break; |
686 | ||
72b603ee AS |
687 | case BPF_ALU | BPF_LSH | BPF_X: |
688 | case BPF_ALU | BPF_RSH | BPF_X: | |
689 | case BPF_ALU | BPF_ARSH | BPF_X: | |
690 | case BPF_ALU64 | BPF_LSH | BPF_X: | |
691 | case BPF_ALU64 | BPF_RSH | BPF_X: | |
692 | case BPF_ALU64 | BPF_ARSH | BPF_X: | |
693 | ||
694 | /* check for bad case when dst_reg == rcx */ | |
695 | if (dst_reg == BPF_REG_4) { | |
696 | /* mov r11, dst_reg */ | |
697 | EMIT_mov(AUX_REG, dst_reg); | |
698 | dst_reg = AUX_REG; | |
699 | } | |
700 | ||
701 | if (src_reg != BPF_REG_4) { /* common case */ | |
702 | EMIT1(0x51); /* push rcx */ | |
703 | ||
704 | /* mov rcx, src_reg */ | |
705 | EMIT_mov(BPF_REG_4, src_reg); | |
706 | } | |
707 | ||
708 | /* shl %rax, %cl | shr %rax, %cl | sar %rax, %cl */ | |
709 | if (BPF_CLASS(insn->code) == BPF_ALU64) | |
710 | EMIT1(add_1mod(0x48, dst_reg)); | |
711 | else if (is_ereg(dst_reg)) | |
712 | EMIT1(add_1mod(0x40, dst_reg)); | |
713 | ||
714 | switch (BPF_OP(insn->code)) { | |
715 | case BPF_LSH: b3 = 0xE0; break; | |
716 | case BPF_RSH: b3 = 0xE8; break; | |
717 | case BPF_ARSH: b3 = 0xF8; break; | |
718 | } | |
719 | EMIT2(0xD3, add_1reg(b3, dst_reg)); | |
720 | ||
721 | if (src_reg != BPF_REG_4) | |
722 | EMIT1(0x59); /* pop rcx */ | |
723 | ||
724 | if (insn->dst_reg == BPF_REG_4) | |
725 | /* mov dst_reg, r11 */ | |
726 | EMIT_mov(insn->dst_reg, AUX_REG); | |
727 | break; | |
728 | ||
62258278 | 729 | case BPF_ALU | BPF_END | BPF_FROM_BE: |
e430f34e | 730 | switch (imm32) { |
62258278 AS |
731 | case 16: |
732 | /* emit 'ror %ax, 8' to swap lower 2 bytes */ | |
733 | EMIT1(0x66); | |
e430f34e | 734 | if (is_ereg(dst_reg)) |
62258278 | 735 | EMIT1(0x41); |
e430f34e | 736 | EMIT3(0xC1, add_1reg(0xC8, dst_reg), 8); |
343f845b AS |
737 | |
738 | /* emit 'movzwl eax, ax' */ | |
739 | if (is_ereg(dst_reg)) | |
740 | EMIT3(0x45, 0x0F, 0xB7); | |
741 | else | |
742 | EMIT2(0x0F, 0xB7); | |
743 | EMIT1(add_2reg(0xC0, dst_reg, dst_reg)); | |
62258278 AS |
744 | break; |
745 | case 32: | |
746 | /* emit 'bswap eax' to swap lower 4 bytes */ | |
e430f34e | 747 | if (is_ereg(dst_reg)) |
62258278 | 748 | EMIT2(0x41, 0x0F); |
0a14842f | 749 | else |
62258278 | 750 | EMIT1(0x0F); |
e430f34e | 751 | EMIT1(add_1reg(0xC8, dst_reg)); |
0a14842f | 752 | break; |
62258278 AS |
753 | case 64: |
754 | /* emit 'bswap rax' to swap 8 bytes */ | |
e430f34e AS |
755 | EMIT3(add_1mod(0x48, dst_reg), 0x0F, |
756 | add_1reg(0xC8, dst_reg)); | |
3b58908a ED |
757 | break; |
758 | } | |
62258278 AS |
759 | break; |
760 | ||
761 | case BPF_ALU | BPF_END | BPF_FROM_LE: | |
343f845b AS |
762 | switch (imm32) { |
763 | case 16: | |
764 | /* emit 'movzwl eax, ax' to zero extend 16-bit | |
765 | * into 64 bit | |
766 | */ | |
767 | if (is_ereg(dst_reg)) | |
768 | EMIT3(0x45, 0x0F, 0xB7); | |
769 | else | |
770 | EMIT2(0x0F, 0xB7); | |
771 | EMIT1(add_2reg(0xC0, dst_reg, dst_reg)); | |
772 | break; | |
773 | case 32: | |
774 | /* emit 'mov eax, eax' to clear upper 32-bits */ | |
775 | if (is_ereg(dst_reg)) | |
776 | EMIT1(0x45); | |
777 | EMIT2(0x89, add_2reg(0xC0, dst_reg, dst_reg)); | |
778 | break; | |
779 | case 64: | |
780 | /* nop */ | |
781 | break; | |
782 | } | |
62258278 AS |
783 | break; |
784 | ||
e430f34e | 785 | /* ST: *(u8*)(dst_reg + off) = imm */ |
62258278 | 786 | case BPF_ST | BPF_MEM | BPF_B: |
e430f34e | 787 | if (is_ereg(dst_reg)) |
62258278 AS |
788 | EMIT2(0x41, 0xC6); |
789 | else | |
790 | EMIT1(0xC6); | |
791 | goto st; | |
792 | case BPF_ST | BPF_MEM | BPF_H: | |
e430f34e | 793 | if (is_ereg(dst_reg)) |
62258278 AS |
794 | EMIT3(0x66, 0x41, 0xC7); |
795 | else | |
796 | EMIT2(0x66, 0xC7); | |
797 | goto st; | |
798 | case BPF_ST | BPF_MEM | BPF_W: | |
e430f34e | 799 | if (is_ereg(dst_reg)) |
62258278 AS |
800 | EMIT2(0x41, 0xC7); |
801 | else | |
802 | EMIT1(0xC7); | |
803 | goto st; | |
804 | case BPF_ST | BPF_MEM | BPF_DW: | |
e430f34e | 805 | EMIT2(add_1mod(0x48, dst_reg), 0xC7); |
62258278 AS |
806 | |
807 | st: if (is_imm8(insn->off)) | |
e430f34e | 808 | EMIT2(add_1reg(0x40, dst_reg), insn->off); |
62258278 | 809 | else |
e430f34e | 810 | EMIT1_off32(add_1reg(0x80, dst_reg), insn->off); |
62258278 | 811 | |
e430f34e | 812 | EMIT(imm32, bpf_size_to_x86_bytes(BPF_SIZE(insn->code))); |
62258278 AS |
813 | break; |
814 | ||
e430f34e | 815 | /* STX: *(u8*)(dst_reg + off) = src_reg */ |
62258278 AS |
816 | case BPF_STX | BPF_MEM | BPF_B: |
817 | /* emit 'mov byte ptr [rax + off], al' */ | |
e430f34e | 818 | if (is_ereg(dst_reg) || is_ereg(src_reg) || |
62258278 | 819 | /* have to add extra byte for x86 SIL, DIL regs */ |
e430f34e AS |
820 | src_reg == BPF_REG_1 || src_reg == BPF_REG_2) |
821 | EMIT2(add_2mod(0x40, dst_reg, src_reg), 0x88); | |
62258278 AS |
822 | else |
823 | EMIT1(0x88); | |
824 | goto stx; | |
825 | case BPF_STX | BPF_MEM | BPF_H: | |
e430f34e AS |
826 | if (is_ereg(dst_reg) || is_ereg(src_reg)) |
827 | EMIT3(0x66, add_2mod(0x40, dst_reg, src_reg), 0x89); | |
62258278 AS |
828 | else |
829 | EMIT2(0x66, 0x89); | |
830 | goto stx; | |
831 | case BPF_STX | BPF_MEM | BPF_W: | |
e430f34e AS |
832 | if (is_ereg(dst_reg) || is_ereg(src_reg)) |
833 | EMIT2(add_2mod(0x40, dst_reg, src_reg), 0x89); | |
62258278 AS |
834 | else |
835 | EMIT1(0x89); | |
836 | goto stx; | |
837 | case BPF_STX | BPF_MEM | BPF_DW: | |
e430f34e | 838 | EMIT2(add_2mod(0x48, dst_reg, src_reg), 0x89); |
62258278 | 839 | stx: if (is_imm8(insn->off)) |
e430f34e | 840 | EMIT2(add_2reg(0x40, dst_reg, src_reg), insn->off); |
62258278 | 841 | else |
e430f34e | 842 | EMIT1_off32(add_2reg(0x80, dst_reg, src_reg), |
62258278 AS |
843 | insn->off); |
844 | break; | |
845 | ||
e430f34e | 846 | /* LDX: dst_reg = *(u8*)(src_reg + off) */ |
62258278 AS |
847 | case BPF_LDX | BPF_MEM | BPF_B: |
848 | /* emit 'movzx rax, byte ptr [rax + off]' */ | |
e430f34e | 849 | EMIT3(add_2mod(0x48, src_reg, dst_reg), 0x0F, 0xB6); |
62258278 AS |
850 | goto ldx; |
851 | case BPF_LDX | BPF_MEM | BPF_H: | |
852 | /* emit 'movzx rax, word ptr [rax + off]' */ | |
e430f34e | 853 | EMIT3(add_2mod(0x48, src_reg, dst_reg), 0x0F, 0xB7); |
62258278 AS |
854 | goto ldx; |
855 | case BPF_LDX | BPF_MEM | BPF_W: | |
856 | /* emit 'mov eax, dword ptr [rax+0x14]' */ | |
e430f34e AS |
857 | if (is_ereg(dst_reg) || is_ereg(src_reg)) |
858 | EMIT2(add_2mod(0x40, src_reg, dst_reg), 0x8B); | |
62258278 AS |
859 | else |
860 | EMIT1(0x8B); | |
861 | goto ldx; | |
862 | case BPF_LDX | BPF_MEM | BPF_DW: | |
863 | /* emit 'mov rax, qword ptr [rax+0x14]' */ | |
e430f34e | 864 | EMIT2(add_2mod(0x48, src_reg, dst_reg), 0x8B); |
62258278 AS |
865 | ldx: /* if insn->off == 0 we can save one extra byte, but |
866 | * special case of x86 r13 which always needs an offset | |
867 | * is not worth the hassle | |
868 | */ | |
869 | if (is_imm8(insn->off)) | |
e430f34e | 870 | EMIT2(add_2reg(0x40, src_reg, dst_reg), insn->off); |
62258278 | 871 | else |
e430f34e | 872 | EMIT1_off32(add_2reg(0x80, src_reg, dst_reg), |
62258278 AS |
873 | insn->off); |
874 | break; | |
875 | ||
e430f34e | 876 | /* STX XADD: lock *(u32*)(dst_reg + off) += src_reg */ |
62258278 AS |
877 | case BPF_STX | BPF_XADD | BPF_W: |
878 | /* emit 'lock add dword ptr [rax + off], eax' */ | |
e430f34e AS |
879 | if (is_ereg(dst_reg) || is_ereg(src_reg)) |
880 | EMIT3(0xF0, add_2mod(0x40, dst_reg, src_reg), 0x01); | |
62258278 AS |
881 | else |
882 | EMIT2(0xF0, 0x01); | |
883 | goto xadd; | |
884 | case BPF_STX | BPF_XADD | BPF_DW: | |
e430f34e | 885 | EMIT3(0xF0, add_2mod(0x48, dst_reg, src_reg), 0x01); |
62258278 | 886 | xadd: if (is_imm8(insn->off)) |
e430f34e | 887 | EMIT2(add_2reg(0x40, dst_reg, src_reg), insn->off); |
62258278 | 888 | else |
e430f34e | 889 | EMIT1_off32(add_2reg(0x80, dst_reg, src_reg), |
62258278 AS |
890 | insn->off); |
891 | break; | |
892 | ||
893 | /* call */ | |
894 | case BPF_JMP | BPF_CALL: | |
e430f34e | 895 | func = (u8 *) __bpf_call_base + imm32; |
62258278 | 896 | jmp_offset = func - (image + addrs[i]); |
e0ee9c12 | 897 | if (seen_ld_abs) { |
17bedab2 | 898 | reload_skb_data = bpf_helper_changes_pkt_data(func); |
4e10df9a AS |
899 | if (reload_skb_data) { |
900 | EMIT1(0x57); /* push %rdi */ | |
901 | jmp_offset += 22; /* pop, mov, sub, mov */ | |
902 | } else { | |
903 | EMIT2(0x41, 0x52); /* push %r10 */ | |
904 | EMIT2(0x41, 0x51); /* push %r9 */ | |
905 | /* need to adjust jmp offset, since | |
906 | * pop %r9, pop %r10 take 4 bytes after call insn | |
907 | */ | |
908 | jmp_offset += 4; | |
909 | } | |
62258278 | 910 | } |
e430f34e | 911 | if (!imm32 || !is_simm32(jmp_offset)) { |
62258278 | 912 | pr_err("unsupported bpf func %d addr %p image %p\n", |
e430f34e | 913 | imm32, func, image); |
62258278 AS |
914 | return -EINVAL; |
915 | } | |
916 | EMIT1_off32(0xE8, jmp_offset); | |
e0ee9c12 | 917 | if (seen_ld_abs) { |
4e10df9a AS |
918 | if (reload_skb_data) { |
919 | EMIT1(0x5F); /* pop %rdi */ | |
920 | emit_load_skb_data_hlen(&prog); | |
921 | } else { | |
922 | EMIT2(0x41, 0x59); /* pop %r9 */ | |
923 | EMIT2(0x41, 0x5A); /* pop %r10 */ | |
924 | } | |
62258278 AS |
925 | } |
926 | break; | |
927 | ||
71189fa9 | 928 | case BPF_JMP | BPF_TAIL_CALL: |
b52f00e6 AS |
929 | emit_bpf_tail_call(&prog); |
930 | break; | |
931 | ||
62258278 AS |
932 | /* cond jump */ |
933 | case BPF_JMP | BPF_JEQ | BPF_X: | |
934 | case BPF_JMP | BPF_JNE | BPF_X: | |
935 | case BPF_JMP | BPF_JGT | BPF_X: | |
52afc51e | 936 | case BPF_JMP | BPF_JLT | BPF_X: |
62258278 | 937 | case BPF_JMP | BPF_JGE | BPF_X: |
52afc51e | 938 | case BPF_JMP | BPF_JLE | BPF_X: |
62258278 | 939 | case BPF_JMP | BPF_JSGT | BPF_X: |
52afc51e | 940 | case BPF_JMP | BPF_JSLT | BPF_X: |
62258278 | 941 | case BPF_JMP | BPF_JSGE | BPF_X: |
52afc51e | 942 | case BPF_JMP | BPF_JSLE | BPF_X: |
e430f34e AS |
943 | /* cmp dst_reg, src_reg */ |
944 | EMIT3(add_2mod(0x48, dst_reg, src_reg), 0x39, | |
945 | add_2reg(0xC0, dst_reg, src_reg)); | |
62258278 AS |
946 | goto emit_cond_jmp; |
947 | ||
948 | case BPF_JMP | BPF_JSET | BPF_X: | |
e430f34e AS |
949 | /* test dst_reg, src_reg */ |
950 | EMIT3(add_2mod(0x48, dst_reg, src_reg), 0x85, | |
951 | add_2reg(0xC0, dst_reg, src_reg)); | |
62258278 AS |
952 | goto emit_cond_jmp; |
953 | ||
954 | case BPF_JMP | BPF_JSET | BPF_K: | |
e430f34e AS |
955 | /* test dst_reg, imm32 */ |
956 | EMIT1(add_1mod(0x48, dst_reg)); | |
957 | EMIT2_off32(0xF7, add_1reg(0xC0, dst_reg), imm32); | |
62258278 AS |
958 | goto emit_cond_jmp; |
959 | ||
960 | case BPF_JMP | BPF_JEQ | BPF_K: | |
961 | case BPF_JMP | BPF_JNE | BPF_K: | |
962 | case BPF_JMP | BPF_JGT | BPF_K: | |
52afc51e | 963 | case BPF_JMP | BPF_JLT | BPF_K: |
62258278 | 964 | case BPF_JMP | BPF_JGE | BPF_K: |
52afc51e | 965 | case BPF_JMP | BPF_JLE | BPF_K: |
62258278 | 966 | case BPF_JMP | BPF_JSGT | BPF_K: |
52afc51e | 967 | case BPF_JMP | BPF_JSLT | BPF_K: |
62258278 | 968 | case BPF_JMP | BPF_JSGE | BPF_K: |
52afc51e | 969 | case BPF_JMP | BPF_JSLE | BPF_K: |
e430f34e AS |
970 | /* cmp dst_reg, imm8/32 */ |
971 | EMIT1(add_1mod(0x48, dst_reg)); | |
62258278 | 972 | |
e430f34e AS |
973 | if (is_imm8(imm32)) |
974 | EMIT3(0x83, add_1reg(0xF8, dst_reg), imm32); | |
62258278 | 975 | else |
e430f34e | 976 | EMIT2_off32(0x81, add_1reg(0xF8, dst_reg), imm32); |
62258278 AS |
977 | |
978 | emit_cond_jmp: /* convert BPF opcode to x86 */ | |
979 | switch (BPF_OP(insn->code)) { | |
980 | case BPF_JEQ: | |
981 | jmp_cond = X86_JE; | |
982 | break; | |
983 | case BPF_JSET: | |
984 | case BPF_JNE: | |
985 | jmp_cond = X86_JNE; | |
986 | break; | |
987 | case BPF_JGT: | |
988 | /* GT is unsigned '>', JA in x86 */ | |
989 | jmp_cond = X86_JA; | |
990 | break; | |
52afc51e DB |
991 | case BPF_JLT: |
992 | /* LT is unsigned '<', JB in x86 */ | |
993 | jmp_cond = X86_JB; | |
994 | break; | |
62258278 AS |
995 | case BPF_JGE: |
996 | /* GE is unsigned '>=', JAE in x86 */ | |
997 | jmp_cond = X86_JAE; | |
998 | break; | |
52afc51e DB |
999 | case BPF_JLE: |
1000 | /* LE is unsigned '<=', JBE in x86 */ | |
1001 | jmp_cond = X86_JBE; | |
1002 | break; | |
62258278 AS |
1003 | case BPF_JSGT: |
1004 | /* signed '>', GT in x86 */ | |
1005 | jmp_cond = X86_JG; | |
1006 | break; | |
52afc51e DB |
1007 | case BPF_JSLT: |
1008 | /* signed '<', LT in x86 */ | |
1009 | jmp_cond = X86_JL; | |
1010 | break; | |
62258278 AS |
1011 | case BPF_JSGE: |
1012 | /* signed '>=', GE in x86 */ | |
1013 | jmp_cond = X86_JGE; | |
1014 | break; | |
52afc51e DB |
1015 | case BPF_JSLE: |
1016 | /* signed '<=', LE in x86 */ | |
1017 | jmp_cond = X86_JLE; | |
1018 | break; | |
62258278 AS |
1019 | default: /* to silence gcc warning */ |
1020 | return -EFAULT; | |
1021 | } | |
1022 | jmp_offset = addrs[i + insn->off] - addrs[i]; | |
1023 | if (is_imm8(jmp_offset)) { | |
1024 | EMIT2(jmp_cond, jmp_offset); | |
1025 | } else if (is_simm32(jmp_offset)) { | |
1026 | EMIT2_off32(0x0F, jmp_cond + 0x10, jmp_offset); | |
1027 | } else { | |
1028 | pr_err("cond_jmp gen bug %llx\n", jmp_offset); | |
1029 | return -EFAULT; | |
1030 | } | |
1031 | ||
1032 | break; | |
0a14842f | 1033 | |
62258278 AS |
1034 | case BPF_JMP | BPF_JA: |
1035 | jmp_offset = addrs[i + insn->off] - addrs[i]; | |
1036 | if (!jmp_offset) | |
1037 | /* optimize out nop jumps */ | |
1038 | break; | |
1039 | emit_jmp: | |
1040 | if (is_imm8(jmp_offset)) { | |
1041 | EMIT2(0xEB, jmp_offset); | |
1042 | } else if (is_simm32(jmp_offset)) { | |
1043 | EMIT1_off32(0xE9, jmp_offset); | |
1044 | } else { | |
1045 | pr_err("jmp gen bug %llx\n", jmp_offset); | |
1046 | return -EFAULT; | |
1047 | } | |
1048 | break; | |
1049 | ||
1050 | case BPF_LD | BPF_IND | BPF_W: | |
1051 | func = sk_load_word; | |
1052 | goto common_load; | |
1053 | case BPF_LD | BPF_ABS | BPF_W: | |
e430f34e | 1054 | func = CHOOSE_LOAD_FUNC(imm32, sk_load_word); |
e0ee9c12 AS |
1055 | common_load: |
1056 | ctx->seen_ld_abs = seen_ld_abs = true; | |
62258278 AS |
1057 | jmp_offset = func - (image + addrs[i]); |
1058 | if (!func || !is_simm32(jmp_offset)) { | |
1059 | pr_err("unsupported bpf func %d addr %p image %p\n", | |
e430f34e | 1060 | imm32, func, image); |
62258278 AS |
1061 | return -EINVAL; |
1062 | } | |
1063 | if (BPF_MODE(insn->code) == BPF_ABS) { | |
1064 | /* mov %esi, imm32 */ | |
e430f34e | 1065 | EMIT1_off32(0xBE, imm32); |
62258278 | 1066 | } else { |
e430f34e AS |
1067 | /* mov %rsi, src_reg */ |
1068 | EMIT_mov(BPF_REG_2, src_reg); | |
1069 | if (imm32) { | |
1070 | if (is_imm8(imm32)) | |
62258278 | 1071 | /* add %esi, imm8 */ |
e430f34e | 1072 | EMIT3(0x83, 0xC6, imm32); |
0a14842f | 1073 | else |
62258278 | 1074 | /* add %esi, imm32 */ |
e430f34e | 1075 | EMIT2_off32(0x81, 0xC6, imm32); |
0a14842f | 1076 | } |
62258278 AS |
1077 | } |
1078 | /* skb pointer is in R6 (%rbx), it will be copied into | |
1079 | * %rdi if skb_copy_bits() call is necessary. | |
1080 | * sk_load_* helpers also use %r10 and %r9d. | |
1081 | * See bpf_jit.S | |
1082 | */ | |
959a7579 DB |
1083 | if (seen_ax_reg) |
1084 | /* r10 = skb->data, mov %r10, off32(%rbx) */ | |
1085 | EMIT3_off32(0x4c, 0x8b, 0x93, | |
1086 | offsetof(struct sk_buff, data)); | |
62258278 AS |
1087 | EMIT1_off32(0xE8, jmp_offset); /* call */ |
1088 | break; | |
1089 | ||
1090 | case BPF_LD | BPF_IND | BPF_H: | |
1091 | func = sk_load_half; | |
1092 | goto common_load; | |
1093 | case BPF_LD | BPF_ABS | BPF_H: | |
e430f34e | 1094 | func = CHOOSE_LOAD_FUNC(imm32, sk_load_half); |
62258278 AS |
1095 | goto common_load; |
1096 | case BPF_LD | BPF_IND | BPF_B: | |
1097 | func = sk_load_byte; | |
1098 | goto common_load; | |
1099 | case BPF_LD | BPF_ABS | BPF_B: | |
e430f34e | 1100 | func = CHOOSE_LOAD_FUNC(imm32, sk_load_byte); |
62258278 AS |
1101 | goto common_load; |
1102 | ||
1103 | case BPF_JMP | BPF_EXIT: | |
769e0de6 | 1104 | if (seen_exit) { |
62258278 AS |
1105 | jmp_offset = ctx->cleanup_addr - addrs[i]; |
1106 | goto emit_jmp; | |
1107 | } | |
769e0de6 | 1108 | seen_exit = true; |
62258278 AS |
1109 | /* update cleanup_addr */ |
1110 | ctx->cleanup_addr = proglen; | |
177366bf AS |
1111 | /* mov rbx, qword ptr [rbp+0] */ |
1112 | EMIT4(0x48, 0x8B, 0x5D, 0); | |
1113 | /* mov r13, qword ptr [rbp+8] */ | |
1114 | EMIT4(0x4C, 0x8B, 0x6D, 8); | |
1115 | /* mov r14, qword ptr [rbp+16] */ | |
1116 | EMIT4(0x4C, 0x8B, 0x75, 16); | |
1117 | /* mov r15, qword ptr [rbp+24] */ | |
1118 | EMIT4(0x4C, 0x8B, 0x7D, 24); | |
1119 | ||
1120 | /* add rbp, AUX_STACK_SPACE */ | |
1121 | EMIT4(0x48, 0x83, 0xC5, AUX_STACK_SPACE); | |
62258278 AS |
1122 | EMIT1(0xC9); /* leave */ |
1123 | EMIT1(0xC3); /* ret */ | |
1124 | break; | |
1125 | ||
f3c2af7b | 1126 | default: |
62258278 AS |
1127 | /* By design x64 JIT should support all BPF instructions |
1128 | * This error will be seen if new instruction was added | |
1129 | * to interpreter, but not to JIT | |
7ae457c1 | 1130 | * or if there is junk in bpf_prog |
62258278 AS |
1131 | */ |
1132 | pr_err("bpf_jit: unknown opcode %02x\n", insn->code); | |
f3c2af7b AS |
1133 | return -EINVAL; |
1134 | } | |
62258278 | 1135 | |
f3c2af7b | 1136 | ilen = prog - temp; |
e0ee9c12 | 1137 | if (ilen > BPF_MAX_INSN_SIZE) { |
9383191d | 1138 | pr_err("bpf_jit: fatal insn size error\n"); |
e0ee9c12 AS |
1139 | return -EFAULT; |
1140 | } | |
1141 | ||
f3c2af7b AS |
1142 | if (image) { |
1143 | if (unlikely(proglen + ilen > oldproglen)) { | |
9383191d | 1144 | pr_err("bpf_jit: fatal error\n"); |
f3c2af7b | 1145 | return -EFAULT; |
0a14842f | 1146 | } |
f3c2af7b | 1147 | memcpy(image + proglen, temp, ilen); |
0a14842f | 1148 | } |
f3c2af7b AS |
1149 | proglen += ilen; |
1150 | addrs[i] = proglen; | |
1151 | prog = temp; | |
1152 | } | |
f3c2af7b AS |
1153 | return proglen; |
1154 | } | |
1155 | ||
1c2a088a AS |
1156 | struct x64_jit_data { |
1157 | struct bpf_binary_header *header; | |
1158 | int *addrs; | |
1159 | u8 *image; | |
1160 | int proglen; | |
1161 | struct jit_context ctx; | |
1162 | }; | |
1163 | ||
d1c55ab5 | 1164 | struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog) |
f3c2af7b AS |
1165 | { |
1166 | struct bpf_binary_header *header = NULL; | |
959a7579 | 1167 | struct bpf_prog *tmp, *orig_prog = prog; |
1c2a088a | 1168 | struct x64_jit_data *jit_data; |
f3c2af7b AS |
1169 | int proglen, oldproglen = 0; |
1170 | struct jit_context ctx = {}; | |
959a7579 | 1171 | bool tmp_blinded = false; |
1c2a088a | 1172 | bool extra_pass = false; |
f3c2af7b AS |
1173 | u8 *image = NULL; |
1174 | int *addrs; | |
1175 | int pass; | |
1176 | int i; | |
1177 | ||
60b58afc | 1178 | if (!prog->jit_requested) |
959a7579 DB |
1179 | return orig_prog; |
1180 | ||
1181 | tmp = bpf_jit_blind_constants(prog); | |
1182 | /* If blinding was requested and we failed during blinding, | |
1183 | * we must fall back to the interpreter. | |
1184 | */ | |
1185 | if (IS_ERR(tmp)) | |
1186 | return orig_prog; | |
1187 | if (tmp != prog) { | |
1188 | tmp_blinded = true; | |
1189 | prog = tmp; | |
1190 | } | |
0a14842f | 1191 | |
1c2a088a AS |
1192 | jit_data = prog->aux->jit_data; |
1193 | if (!jit_data) { | |
1194 | jit_data = kzalloc(sizeof(*jit_data), GFP_KERNEL); | |
1195 | if (!jit_data) { | |
1196 | prog = orig_prog; | |
1197 | goto out; | |
1198 | } | |
1199 | prog->aux->jit_data = jit_data; | |
1200 | } | |
1201 | addrs = jit_data->addrs; | |
1202 | if (addrs) { | |
1203 | ctx = jit_data->ctx; | |
1204 | oldproglen = jit_data->proglen; | |
1205 | image = jit_data->image; | |
1206 | header = jit_data->header; | |
1207 | extra_pass = true; | |
1208 | goto skip_init_addrs; | |
1209 | } | |
f3c2af7b | 1210 | addrs = kmalloc(prog->len * sizeof(*addrs), GFP_KERNEL); |
959a7579 DB |
1211 | if (!addrs) { |
1212 | prog = orig_prog; | |
1c2a088a | 1213 | goto out_addrs; |
959a7579 | 1214 | } |
f3c2af7b AS |
1215 | |
1216 | /* Before first pass, make a rough estimation of addrs[] | |
1217 | * each bpf instruction is translated to less than 64 bytes | |
1218 | */ | |
1219 | for (proglen = 0, i = 0; i < prog->len; i++) { | |
1220 | proglen += 64; | |
1221 | addrs[i] = proglen; | |
1222 | } | |
1223 | ctx.cleanup_addr = proglen; | |
1c2a088a | 1224 | skip_init_addrs: |
f3c2af7b | 1225 | |
3f7352bf AS |
1226 | /* JITed image shrinks with every pass and the loop iterates |
1227 | * until the image stops shrinking. Very large bpf programs | |
1228 | * may converge on the last pass. In such case do one more | |
1229 | * pass to emit the final image | |
1230 | */ | |
1231 | for (pass = 0; pass < 10 || image; pass++) { | |
f3c2af7b AS |
1232 | proglen = do_jit(prog, addrs, image, oldproglen, &ctx); |
1233 | if (proglen <= 0) { | |
1234 | image = NULL; | |
1235 | if (header) | |
738cbe72 | 1236 | bpf_jit_binary_free(header); |
959a7579 DB |
1237 | prog = orig_prog; |
1238 | goto out_addrs; | |
f3c2af7b | 1239 | } |
0a14842f | 1240 | if (image) { |
e0ee9c12 | 1241 | if (proglen != oldproglen) { |
f3c2af7b AS |
1242 | pr_err("bpf_jit: proglen=%d != oldproglen=%d\n", |
1243 | proglen, oldproglen); | |
959a7579 DB |
1244 | prog = orig_prog; |
1245 | goto out_addrs; | |
e0ee9c12 | 1246 | } |
0a14842f ED |
1247 | break; |
1248 | } | |
1249 | if (proglen == oldproglen) { | |
738cbe72 DB |
1250 | header = bpf_jit_binary_alloc(proglen, &image, |
1251 | 1, jit_fill_hole); | |
959a7579 DB |
1252 | if (!header) { |
1253 | prog = orig_prog; | |
1254 | goto out_addrs; | |
1255 | } | |
0a14842f ED |
1256 | } |
1257 | oldproglen = proglen; | |
1258 | } | |
79617801 | 1259 | |
0a14842f | 1260 | if (bpf_jit_enable > 1) |
485d6511 | 1261 | bpf_jit_dump(prog->len, proglen, pass + 1, image); |
0a14842f ED |
1262 | |
1263 | if (image) { | |
314beb9b | 1264 | bpf_flush_icache(header, image + proglen); |
1c2a088a AS |
1265 | if (!prog->is_func || extra_pass) { |
1266 | bpf_jit_binary_lock_ro(header); | |
1267 | } else { | |
1268 | jit_data->addrs = addrs; | |
1269 | jit_data->ctx = ctx; | |
1270 | jit_data->proglen = proglen; | |
1271 | jit_data->image = image; | |
1272 | jit_data->header = header; | |
1273 | } | |
f3c2af7b | 1274 | prog->bpf_func = (void *)image; |
a91263d5 | 1275 | prog->jited = 1; |
783d28dd | 1276 | prog->jited_len = proglen; |
9d5ecb09 DB |
1277 | } else { |
1278 | prog = orig_prog; | |
0a14842f | 1279 | } |
959a7579 | 1280 | |
1c2a088a | 1281 | if (!prog->is_func || extra_pass) { |
959a7579 | 1282 | out_addrs: |
1c2a088a AS |
1283 | kfree(addrs); |
1284 | kfree(jit_data); | |
1285 | prog->aux->jit_data = NULL; | |
1286 | } | |
959a7579 DB |
1287 | out: |
1288 | if (tmp_blinded) | |
1289 | bpf_jit_prog_release_other(prog, prog == orig_prog ? | |
1290 | tmp : orig_prog); | |
d1c55ab5 | 1291 | return prog; |
0a14842f | 1292 | } |