Commit | Line | Data |
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a2c7a983 IM |
1 | /* |
2 | * bpf_jit_comp.c: BPF JIT compiler | |
0a14842f | 3 | * |
3b58908a | 4 | * Copyright (C) 2011-2013 Eric Dumazet (eric.dumazet@gmail.com) |
62258278 | 5 | * Internal BPF Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com |
0a14842f ED |
6 | * |
7 | * This program is free software; you can redistribute it and/or | |
8 | * modify it under the terms of the GNU General Public License | |
9 | * as published by the Free Software Foundation; version 2 | |
10 | * of the License. | |
11 | */ | |
0a14842f ED |
12 | #include <linux/netdevice.h> |
13 | #include <linux/filter.h> | |
855ddb56 | 14 | #include <linux/if_vlan.h> |
71d22d58 DB |
15 | #include <linux/bpf.h> |
16 | ||
d1163651 | 17 | #include <asm/set_memory.h> |
a493a87f | 18 | #include <asm/nospec-branch.h> |
0a14842f | 19 | |
5cccc702 | 20 | static u8 *emit_code(u8 *ptr, u32 bytes, unsigned int len) |
0a14842f ED |
21 | { |
22 | if (len == 1) | |
23 | *ptr = bytes; | |
24 | else if (len == 2) | |
25 | *(u16 *)ptr = bytes; | |
26 | else { | |
27 | *(u32 *)ptr = bytes; | |
28 | barrier(); | |
29 | } | |
30 | return ptr + len; | |
31 | } | |
32 | ||
b52f00e6 AS |
33 | #define EMIT(bytes, len) \ |
34 | do { prog = emit_code(prog, bytes, len); cnt += len; } while (0) | |
0a14842f ED |
35 | |
36 | #define EMIT1(b1) EMIT(b1, 1) | |
37 | #define EMIT2(b1, b2) EMIT((b1) + ((b2) << 8), 2) | |
38 | #define EMIT3(b1, b2, b3) EMIT((b1) + ((b2) << 8) + ((b3) << 16), 3) | |
39 | #define EMIT4(b1, b2, b3, b4) EMIT((b1) + ((b2) << 8) + ((b3) << 16) + ((b4) << 24), 4) | |
a2c7a983 | 40 | |
62258278 | 41 | #define EMIT1_off32(b1, off) \ |
a2c7a983 | 42 | do { EMIT1(b1); EMIT(off, 4); } while (0) |
62258278 | 43 | #define EMIT2_off32(b1, b2, off) \ |
a2c7a983 | 44 | do { EMIT2(b1, b2); EMIT(off, 4); } while (0) |
62258278 | 45 | #define EMIT3_off32(b1, b2, b3, off) \ |
a2c7a983 | 46 | do { EMIT3(b1, b2, b3); EMIT(off, 4); } while (0) |
62258278 | 47 | #define EMIT4_off32(b1, b2, b3, b4, off) \ |
a2c7a983 | 48 | do { EMIT4(b1, b2, b3, b4); EMIT(off, 4); } while (0) |
0a14842f | 49 | |
5cccc702 | 50 | static bool is_imm8(int value) |
0a14842f ED |
51 | { |
52 | return value <= 127 && value >= -128; | |
53 | } | |
54 | ||
5cccc702 | 55 | static bool is_simm32(s64 value) |
0a14842f | 56 | { |
6fe8b9c1 DB |
57 | return value == (s64)(s32)value; |
58 | } | |
59 | ||
60 | static bool is_uimm32(u64 value) | |
61 | { | |
62 | return value == (u64)(u32)value; | |
0a14842f ED |
63 | } |
64 | ||
e430f34e | 65 | /* mov dst, src */ |
a2c7a983 IM |
66 | #define EMIT_mov(DST, SRC) \ |
67 | do { \ | |
68 | if (DST != SRC) \ | |
69 | EMIT3(add_2mod(0x48, DST, SRC), 0x89, add_2reg(0xC0, DST, SRC)); \ | |
62258278 AS |
70 | } while (0) |
71 | ||
72 | static int bpf_size_to_x86_bytes(int bpf_size) | |
73 | { | |
74 | if (bpf_size == BPF_W) | |
75 | return 4; | |
76 | else if (bpf_size == BPF_H) | |
77 | return 2; | |
78 | else if (bpf_size == BPF_B) | |
79 | return 1; | |
80 | else if (bpf_size == BPF_DW) | |
81 | return 4; /* imm32 */ | |
82 | else | |
83 | return 0; | |
84 | } | |
0a14842f | 85 | |
a2c7a983 IM |
86 | /* |
87 | * List of x86 cond jumps opcodes (. + s8) | |
0a14842f ED |
88 | * Add 0x10 (and an extra 0x0f) to generate far jumps (. + s32) |
89 | */ | |
90 | #define X86_JB 0x72 | |
91 | #define X86_JAE 0x73 | |
92 | #define X86_JE 0x74 | |
93 | #define X86_JNE 0x75 | |
94 | #define X86_JBE 0x76 | |
95 | #define X86_JA 0x77 | |
52afc51e | 96 | #define X86_JL 0x7C |
62258278 | 97 | #define X86_JGE 0x7D |
52afc51e | 98 | #define X86_JLE 0x7E |
62258278 | 99 | #define X86_JG 0x7F |
0a14842f | 100 | |
a2c7a983 | 101 | /* Pick a register outside of BPF range for JIT internal work */ |
959a7579 | 102 | #define AUX_REG (MAX_BPF_JIT_REG + 1) |
62258278 | 103 | |
a2c7a983 IM |
104 | /* |
105 | * The following table maps BPF registers to x86-64 registers. | |
959a7579 | 106 | * |
a2c7a983 | 107 | * x86-64 register R12 is unused, since if used as base address |
959a7579 DB |
108 | * register in load/store instructions, it always needs an |
109 | * extra byte of encoding and is callee saved. | |
110 | * | |
e782bdcf DB |
111 | * Also x86-64 register R9 is unused. x86-64 register R10 is |
112 | * used for blinding (if enabled). | |
62258278 AS |
113 | */ |
114 | static const int reg2hex[] = { | |
a2c7a983 IM |
115 | [BPF_REG_0] = 0, /* RAX */ |
116 | [BPF_REG_1] = 7, /* RDI */ | |
117 | [BPF_REG_2] = 6, /* RSI */ | |
118 | [BPF_REG_3] = 2, /* RDX */ | |
119 | [BPF_REG_4] = 1, /* RCX */ | |
120 | [BPF_REG_5] = 0, /* R8 */ | |
121 | [BPF_REG_6] = 3, /* RBX callee saved */ | |
122 | [BPF_REG_7] = 5, /* R13 callee saved */ | |
123 | [BPF_REG_8] = 6, /* R14 callee saved */ | |
124 | [BPF_REG_9] = 7, /* R15 callee saved */ | |
125 | [BPF_REG_FP] = 5, /* RBP readonly */ | |
126 | [BPF_REG_AX] = 2, /* R10 temp register */ | |
127 | [AUX_REG] = 3, /* R11 temp register */ | |
62258278 AS |
128 | }; |
129 | ||
a2c7a983 IM |
130 | /* |
131 | * is_ereg() == true if BPF register 'reg' maps to x86-64 r8..r15 | |
62258278 AS |
132 | * which need extra byte of encoding. |
133 | * rax,rcx,...,rbp have simpler encoding | |
134 | */ | |
5cccc702 | 135 | static bool is_ereg(u32 reg) |
62258278 | 136 | { |
d148134b JP |
137 | return (1 << reg) & (BIT(BPF_REG_5) | |
138 | BIT(AUX_REG) | | |
139 | BIT(BPF_REG_7) | | |
140 | BIT(BPF_REG_8) | | |
959a7579 DB |
141 | BIT(BPF_REG_9) | |
142 | BIT(BPF_REG_AX)); | |
62258278 AS |
143 | } |
144 | ||
de0a444d DB |
145 | static bool is_axreg(u32 reg) |
146 | { | |
147 | return reg == BPF_REG_0; | |
148 | } | |
149 | ||
a2c7a983 | 150 | /* Add modifiers if 'reg' maps to x86-64 registers R8..R15 */ |
5cccc702 | 151 | static u8 add_1mod(u8 byte, u32 reg) |
62258278 AS |
152 | { |
153 | if (is_ereg(reg)) | |
154 | byte |= 1; | |
155 | return byte; | |
156 | } | |
157 | ||
5cccc702 | 158 | static u8 add_2mod(u8 byte, u32 r1, u32 r2) |
62258278 AS |
159 | { |
160 | if (is_ereg(r1)) | |
161 | byte |= 1; | |
162 | if (is_ereg(r2)) | |
163 | byte |= 4; | |
164 | return byte; | |
165 | } | |
166 | ||
a2c7a983 | 167 | /* Encode 'dst_reg' register into x86-64 opcode 'byte' */ |
5cccc702 | 168 | static u8 add_1reg(u8 byte, u32 dst_reg) |
62258278 | 169 | { |
e430f34e | 170 | return byte + reg2hex[dst_reg]; |
62258278 AS |
171 | } |
172 | ||
a2c7a983 | 173 | /* Encode 'dst_reg' and 'src_reg' registers into x86-64 opcode 'byte' */ |
5cccc702 | 174 | static u8 add_2reg(u8 byte, u32 dst_reg, u32 src_reg) |
62258278 | 175 | { |
e430f34e | 176 | return byte + reg2hex[dst_reg] + (reg2hex[src_reg] << 3); |
62258278 AS |
177 | } |
178 | ||
738cbe72 DB |
179 | static void jit_fill_hole(void *area, unsigned int size) |
180 | { | |
a2c7a983 | 181 | /* Fill whole space with INT3 instructions */ |
738cbe72 DB |
182 | memset(area, 0xcc, size); |
183 | } | |
184 | ||
f3c2af7b | 185 | struct jit_context { |
a2c7a983 | 186 | int cleanup_addr; /* Epilogue code offset */ |
f3c2af7b AS |
187 | }; |
188 | ||
a2c7a983 | 189 | /* Maximum number of bytes emitted while JITing one eBPF insn */ |
e0ee9c12 AS |
190 | #define BPF_MAX_INSN_SIZE 128 |
191 | #define BPF_INSN_SAFETY 64 | |
192 | ||
e782bdcf | 193 | #define AUX_STACK_SPACE 40 /* Space for RBX, R13, R14, R15, tailcnt */ |
b52f00e6 | 194 | |
e782bdcf | 195 | #define PROLOGUE_SIZE 37 |
b52f00e6 | 196 | |
a2c7a983 IM |
197 | /* |
198 | * Emit x86-64 prologue code for BPF program and check its size. | |
b52f00e6 AS |
199 | * bpf_tail_call helper will skip it while jumping into another program |
200 | */ | |
08691752 | 201 | static void emit_prologue(u8 **pprog, u32 stack_depth, bool ebpf_from_cbpf) |
0a14842f | 202 | { |
b52f00e6 AS |
203 | u8 *prog = *pprog; |
204 | int cnt = 0; | |
0a14842f | 205 | |
a2c7a983 IM |
206 | /* push rbp */ |
207 | EMIT1(0x55); | |
208 | ||
209 | /* mov rbp,rsp */ | |
210 | EMIT3(0x48, 0x89, 0xE5); | |
0a14842f | 211 | |
2960ae48 AS |
212 | /* sub rsp, rounded_stack_depth + AUX_STACK_SPACE */ |
213 | EMIT3_off32(0x48, 0x81, 0xEC, | |
214 | round_up(stack_depth, 8) + AUX_STACK_SPACE); | |
177366bf AS |
215 | |
216 | /* sub rbp, AUX_STACK_SPACE */ | |
217 | EMIT4(0x48, 0x83, 0xED, AUX_STACK_SPACE); | |
62258278 | 218 | |
177366bf AS |
219 | /* mov qword ptr [rbp+0],rbx */ |
220 | EMIT4(0x48, 0x89, 0x5D, 0); | |
177366bf AS |
221 | /* mov qword ptr [rbp+8],r13 */ |
222 | EMIT4(0x4C, 0x89, 0x6D, 8); | |
223 | /* mov qword ptr [rbp+16],r14 */ | |
224 | EMIT4(0x4C, 0x89, 0x75, 16); | |
225 | /* mov qword ptr [rbp+24],r15 */ | |
226 | EMIT4(0x4C, 0x89, 0x7D, 24); | |
62258278 | 227 | |
08691752 | 228 | if (!ebpf_from_cbpf) { |
a2c7a983 IM |
229 | /* |
230 | * Clear the tail call counter (tail_call_cnt): for eBPF tail | |
08691752 | 231 | * calls we need to reset the counter to 0. It's done in two |
a2c7a983 | 232 | * instructions, resetting RAX register to 0, and moving it |
08691752 DB |
233 | * to the counter location. |
234 | */ | |
62258278 | 235 | |
08691752 DB |
236 | /* xor eax, eax */ |
237 | EMIT2(0x31, 0xc0); | |
238 | /* mov qword ptr [rbp+32], rax */ | |
239 | EMIT4(0x48, 0x89, 0x45, 32); | |
240 | ||
241 | BUILD_BUG_ON(cnt != PROLOGUE_SIZE); | |
242 | } | |
b52f00e6 | 243 | |
b52f00e6 AS |
244 | *pprog = prog; |
245 | } | |
246 | ||
a2c7a983 IM |
247 | /* |
248 | * Generate the following code: | |
249 | * | |
b52f00e6 AS |
250 | * ... bpf_tail_call(void *ctx, struct bpf_array *array, u64 index) ... |
251 | * if (index >= array->map.max_entries) | |
252 | * goto out; | |
253 | * if (++tail_call_cnt > MAX_TAIL_CALL_CNT) | |
254 | * goto out; | |
2a36f0b9 | 255 | * prog = array->ptrs[index]; |
b52f00e6 AS |
256 | * if (prog == NULL) |
257 | * goto out; | |
258 | * goto *(prog->bpf_func + prologue_size); | |
259 | * out: | |
260 | */ | |
261 | static void emit_bpf_tail_call(u8 **pprog) | |
262 | { | |
263 | u8 *prog = *pprog; | |
264 | int label1, label2, label3; | |
265 | int cnt = 0; | |
266 | ||
a2c7a983 IM |
267 | /* |
268 | * rdi - pointer to ctx | |
b52f00e6 AS |
269 | * rsi - pointer to bpf_array |
270 | * rdx - index in bpf_array | |
271 | */ | |
272 | ||
a2c7a983 IM |
273 | /* |
274 | * if (index >= array->map.max_entries) | |
275 | * goto out; | |
b52f00e6 | 276 | */ |
90caccdd AS |
277 | EMIT2(0x89, 0xD2); /* mov edx, edx */ |
278 | EMIT3(0x39, 0x56, /* cmp dword ptr [rsi + 16], edx */ | |
b52f00e6 | 279 | offsetof(struct bpf_array, map.max_entries)); |
a2c7a983 | 280 | #define OFFSET1 (41 + RETPOLINE_RAX_BPF_JIT_SIZE) /* Number of bytes to jump */ |
b52f00e6 AS |
281 | EMIT2(X86_JBE, OFFSET1); /* jbe out */ |
282 | label1 = cnt; | |
283 | ||
a2c7a983 IM |
284 | /* |
285 | * if (tail_call_cnt > MAX_TAIL_CALL_CNT) | |
286 | * goto out; | |
b52f00e6 | 287 | */ |
177366bf | 288 | EMIT2_off32(0x8B, 0x85, 36); /* mov eax, dword ptr [rbp + 36] */ |
b52f00e6 | 289 | EMIT3(0x83, 0xF8, MAX_TAIL_CALL_CNT); /* cmp eax, MAX_TAIL_CALL_CNT */ |
a493a87f | 290 | #define OFFSET2 (30 + RETPOLINE_RAX_BPF_JIT_SIZE) |
b52f00e6 AS |
291 | EMIT2(X86_JA, OFFSET2); /* ja out */ |
292 | label2 = cnt; | |
293 | EMIT3(0x83, 0xC0, 0x01); /* add eax, 1 */ | |
177366bf | 294 | EMIT2_off32(0x89, 0x85, 36); /* mov dword ptr [rbp + 36], eax */ |
b52f00e6 | 295 | |
2a36f0b9 | 296 | /* prog = array->ptrs[index]; */ |
84ccac6e | 297 | EMIT4_off32(0x48, 0x8B, 0x84, 0xD6, /* mov rax, [rsi + rdx * 8 + offsetof(...)] */ |
2a36f0b9 | 298 | offsetof(struct bpf_array, ptrs)); |
b52f00e6 | 299 | |
a2c7a983 IM |
300 | /* |
301 | * if (prog == NULL) | |
302 | * goto out; | |
b52f00e6 | 303 | */ |
84ccac6e | 304 | EMIT3(0x48, 0x85, 0xC0); /* test rax,rax */ |
a493a87f | 305 | #define OFFSET3 (8 + RETPOLINE_RAX_BPF_JIT_SIZE) |
b52f00e6 AS |
306 | EMIT2(X86_JE, OFFSET3); /* je out */ |
307 | label3 = cnt; | |
308 | ||
309 | /* goto *(prog->bpf_func + prologue_size); */ | |
310 | EMIT4(0x48, 0x8B, 0x40, /* mov rax, qword ptr [rax + 32] */ | |
311 | offsetof(struct bpf_prog, bpf_func)); | |
312 | EMIT4(0x48, 0x83, 0xC0, PROLOGUE_SIZE); /* add rax, prologue_size */ | |
313 | ||
a2c7a983 IM |
314 | /* |
315 | * Wow we're ready to jump into next BPF program | |
b52f00e6 AS |
316 | * rdi == ctx (1st arg) |
317 | * rax == prog->bpf_func + prologue_size | |
318 | */ | |
a493a87f | 319 | RETPOLINE_RAX_BPF_JIT(); |
b52f00e6 AS |
320 | |
321 | /* out: */ | |
322 | BUILD_BUG_ON(cnt - label1 != OFFSET1); | |
323 | BUILD_BUG_ON(cnt - label2 != OFFSET2); | |
324 | BUILD_BUG_ON(cnt - label3 != OFFSET3); | |
325 | *pprog = prog; | |
326 | } | |
327 | ||
6fe8b9c1 DB |
328 | static void emit_mov_imm32(u8 **pprog, bool sign_propagate, |
329 | u32 dst_reg, const u32 imm32) | |
330 | { | |
331 | u8 *prog = *pprog; | |
332 | u8 b1, b2, b3; | |
333 | int cnt = 0; | |
334 | ||
a2c7a983 IM |
335 | /* |
336 | * Optimization: if imm32 is positive, use 'mov %eax, imm32' | |
6fe8b9c1 DB |
337 | * (which zero-extends imm32) to save 2 bytes. |
338 | */ | |
339 | if (sign_propagate && (s32)imm32 < 0) { | |
340 | /* 'mov %rax, imm32' sign extends imm32 */ | |
341 | b1 = add_1mod(0x48, dst_reg); | |
342 | b2 = 0xC7; | |
343 | b3 = 0xC0; | |
344 | EMIT3_off32(b1, b2, add_1reg(b3, dst_reg), imm32); | |
345 | goto done; | |
346 | } | |
347 | ||
a2c7a983 IM |
348 | /* |
349 | * Optimization: if imm32 is zero, use 'xor %eax, %eax' | |
6fe8b9c1 DB |
350 | * to save 3 bytes. |
351 | */ | |
352 | if (imm32 == 0) { | |
353 | if (is_ereg(dst_reg)) | |
354 | EMIT1(add_2mod(0x40, dst_reg, dst_reg)); | |
355 | b2 = 0x31; /* xor */ | |
356 | b3 = 0xC0; | |
357 | EMIT2(b2, add_2reg(b3, dst_reg, dst_reg)); | |
358 | goto done; | |
359 | } | |
360 | ||
361 | /* mov %eax, imm32 */ | |
362 | if (is_ereg(dst_reg)) | |
363 | EMIT1(add_1mod(0x40, dst_reg)); | |
364 | EMIT1_off32(add_1reg(0xB8, dst_reg), imm32); | |
365 | done: | |
366 | *pprog = prog; | |
367 | } | |
368 | ||
369 | static void emit_mov_imm64(u8 **pprog, u32 dst_reg, | |
370 | const u32 imm32_hi, const u32 imm32_lo) | |
371 | { | |
372 | u8 *prog = *pprog; | |
373 | int cnt = 0; | |
374 | ||
375 | if (is_uimm32(((u64)imm32_hi << 32) | (u32)imm32_lo)) { | |
a2c7a983 IM |
376 | /* |
377 | * For emitting plain u32, where sign bit must not be | |
6fe8b9c1 DB |
378 | * propagated LLVM tends to load imm64 over mov32 |
379 | * directly, so save couple of bytes by just doing | |
380 | * 'mov %eax, imm32' instead. | |
381 | */ | |
382 | emit_mov_imm32(&prog, false, dst_reg, imm32_lo); | |
383 | } else { | |
384 | /* movabsq %rax, imm64 */ | |
385 | EMIT2(add_1mod(0x48, dst_reg), add_1reg(0xB8, dst_reg)); | |
386 | EMIT(imm32_lo, 4); | |
387 | EMIT(imm32_hi, 4); | |
388 | } | |
389 | ||
390 | *pprog = prog; | |
391 | } | |
392 | ||
4c38e2f3 DB |
393 | static void emit_mov_reg(u8 **pprog, bool is64, u32 dst_reg, u32 src_reg) |
394 | { | |
395 | u8 *prog = *pprog; | |
396 | int cnt = 0; | |
397 | ||
398 | if (is64) { | |
399 | /* mov dst, src */ | |
400 | EMIT_mov(dst_reg, src_reg); | |
401 | } else { | |
402 | /* mov32 dst, src */ | |
403 | if (is_ereg(dst_reg) || is_ereg(src_reg)) | |
404 | EMIT1(add_2mod(0x40, dst_reg, src_reg)); | |
405 | EMIT2(0x89, add_2reg(0xC0, dst_reg, src_reg)); | |
406 | } | |
407 | ||
408 | *pprog = prog; | |
409 | } | |
410 | ||
b52f00e6 AS |
411 | static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image, |
412 | int oldproglen, struct jit_context *ctx) | |
413 | { | |
414 | struct bpf_insn *insn = bpf_prog->insnsi; | |
415 | int insn_cnt = bpf_prog->len; | |
b52f00e6 AS |
416 | bool seen_exit = false; |
417 | u8 temp[BPF_MAX_INSN_SIZE + BPF_INSN_SAFETY]; | |
418 | int i, cnt = 0; | |
419 | int proglen = 0; | |
420 | u8 *prog = temp; | |
421 | ||
08691752 DB |
422 | emit_prologue(&prog, bpf_prog->aux->stack_depth, |
423 | bpf_prog_was_classic(bpf_prog)); | |
b52f00e6 | 424 | |
62258278 | 425 | for (i = 0; i < insn_cnt; i++, insn++) { |
e430f34e AS |
426 | const s32 imm32 = insn->imm; |
427 | u32 dst_reg = insn->dst_reg; | |
428 | u32 src_reg = insn->src_reg; | |
6fe8b9c1 | 429 | u8 b2 = 0, b3 = 0; |
62258278 AS |
430 | s64 jmp_offset; |
431 | u8 jmp_cond; | |
432 | int ilen; | |
433 | u8 *func; | |
434 | ||
435 | switch (insn->code) { | |
436 | /* ALU */ | |
437 | case BPF_ALU | BPF_ADD | BPF_X: | |
438 | case BPF_ALU | BPF_SUB | BPF_X: | |
439 | case BPF_ALU | BPF_AND | BPF_X: | |
440 | case BPF_ALU | BPF_OR | BPF_X: | |
441 | case BPF_ALU | BPF_XOR | BPF_X: | |
442 | case BPF_ALU64 | BPF_ADD | BPF_X: | |
443 | case BPF_ALU64 | BPF_SUB | BPF_X: | |
444 | case BPF_ALU64 | BPF_AND | BPF_X: | |
445 | case BPF_ALU64 | BPF_OR | BPF_X: | |
446 | case BPF_ALU64 | BPF_XOR | BPF_X: | |
447 | switch (BPF_OP(insn->code)) { | |
448 | case BPF_ADD: b2 = 0x01; break; | |
449 | case BPF_SUB: b2 = 0x29; break; | |
450 | case BPF_AND: b2 = 0x21; break; | |
451 | case BPF_OR: b2 = 0x09; break; | |
452 | case BPF_XOR: b2 = 0x31; break; | |
0a14842f | 453 | } |
62258278 | 454 | if (BPF_CLASS(insn->code) == BPF_ALU64) |
e430f34e AS |
455 | EMIT1(add_2mod(0x48, dst_reg, src_reg)); |
456 | else if (is_ereg(dst_reg) || is_ereg(src_reg)) | |
457 | EMIT1(add_2mod(0x40, dst_reg, src_reg)); | |
458 | EMIT2(b2, add_2reg(0xC0, dst_reg, src_reg)); | |
62258278 | 459 | break; |
0a14842f | 460 | |
62258278 | 461 | case BPF_ALU64 | BPF_MOV | BPF_X: |
62258278 | 462 | case BPF_ALU | BPF_MOV | BPF_X: |
4c38e2f3 DB |
463 | emit_mov_reg(&prog, |
464 | BPF_CLASS(insn->code) == BPF_ALU64, | |
465 | dst_reg, src_reg); | |
62258278 | 466 | break; |
0a14842f | 467 | |
e430f34e | 468 | /* neg dst */ |
62258278 AS |
469 | case BPF_ALU | BPF_NEG: |
470 | case BPF_ALU64 | BPF_NEG: | |
471 | if (BPF_CLASS(insn->code) == BPF_ALU64) | |
e430f34e AS |
472 | EMIT1(add_1mod(0x48, dst_reg)); |
473 | else if (is_ereg(dst_reg)) | |
474 | EMIT1(add_1mod(0x40, dst_reg)); | |
475 | EMIT2(0xF7, add_1reg(0xD8, dst_reg)); | |
62258278 AS |
476 | break; |
477 | ||
478 | case BPF_ALU | BPF_ADD | BPF_K: | |
479 | case BPF_ALU | BPF_SUB | BPF_K: | |
480 | case BPF_ALU | BPF_AND | BPF_K: | |
481 | case BPF_ALU | BPF_OR | BPF_K: | |
482 | case BPF_ALU | BPF_XOR | BPF_K: | |
483 | case BPF_ALU64 | BPF_ADD | BPF_K: | |
484 | case BPF_ALU64 | BPF_SUB | BPF_K: | |
485 | case BPF_ALU64 | BPF_AND | BPF_K: | |
486 | case BPF_ALU64 | BPF_OR | BPF_K: | |
487 | case BPF_ALU64 | BPF_XOR | BPF_K: | |
488 | if (BPF_CLASS(insn->code) == BPF_ALU64) | |
e430f34e AS |
489 | EMIT1(add_1mod(0x48, dst_reg)); |
490 | else if (is_ereg(dst_reg)) | |
491 | EMIT1(add_1mod(0x40, dst_reg)); | |
62258278 | 492 | |
a2c7a983 IM |
493 | /* |
494 | * b3 holds 'normal' opcode, b2 short form only valid | |
de0a444d DB |
495 | * in case dst is eax/rax. |
496 | */ | |
62258278 | 497 | switch (BPF_OP(insn->code)) { |
de0a444d DB |
498 | case BPF_ADD: |
499 | b3 = 0xC0; | |
500 | b2 = 0x05; | |
501 | break; | |
502 | case BPF_SUB: | |
503 | b3 = 0xE8; | |
504 | b2 = 0x2D; | |
505 | break; | |
506 | case BPF_AND: | |
507 | b3 = 0xE0; | |
508 | b2 = 0x25; | |
509 | break; | |
510 | case BPF_OR: | |
511 | b3 = 0xC8; | |
512 | b2 = 0x0D; | |
513 | break; | |
514 | case BPF_XOR: | |
515 | b3 = 0xF0; | |
516 | b2 = 0x35; | |
517 | break; | |
62258278 AS |
518 | } |
519 | ||
e430f34e AS |
520 | if (is_imm8(imm32)) |
521 | EMIT3(0x83, add_1reg(b3, dst_reg), imm32); | |
de0a444d DB |
522 | else if (is_axreg(dst_reg)) |
523 | EMIT1_off32(b2, imm32); | |
62258278 | 524 | else |
e430f34e | 525 | EMIT2_off32(0x81, add_1reg(b3, dst_reg), imm32); |
62258278 AS |
526 | break; |
527 | ||
528 | case BPF_ALU64 | BPF_MOV | BPF_K: | |
62258278 | 529 | case BPF_ALU | BPF_MOV | BPF_K: |
6fe8b9c1 DB |
530 | emit_mov_imm32(&prog, BPF_CLASS(insn->code) == BPF_ALU64, |
531 | dst_reg, imm32); | |
62258278 AS |
532 | break; |
533 | ||
02ab695b | 534 | case BPF_LD | BPF_IMM | BPF_DW: |
6fe8b9c1 | 535 | emit_mov_imm64(&prog, dst_reg, insn[1].imm, insn[0].imm); |
02ab695b AS |
536 | insn++; |
537 | i++; | |
538 | break; | |
539 | ||
e430f34e | 540 | /* dst %= src, dst /= src, dst %= imm32, dst /= imm32 */ |
62258278 AS |
541 | case BPF_ALU | BPF_MOD | BPF_X: |
542 | case BPF_ALU | BPF_DIV | BPF_X: | |
543 | case BPF_ALU | BPF_MOD | BPF_K: | |
544 | case BPF_ALU | BPF_DIV | BPF_K: | |
545 | case BPF_ALU64 | BPF_MOD | BPF_X: | |
546 | case BPF_ALU64 | BPF_DIV | BPF_X: | |
547 | case BPF_ALU64 | BPF_MOD | BPF_K: | |
548 | case BPF_ALU64 | BPF_DIV | BPF_K: | |
549 | EMIT1(0x50); /* push rax */ | |
550 | EMIT1(0x52); /* push rdx */ | |
551 | ||
552 | if (BPF_SRC(insn->code) == BPF_X) | |
e430f34e AS |
553 | /* mov r11, src_reg */ |
554 | EMIT_mov(AUX_REG, src_reg); | |
62258278 | 555 | else |
e430f34e AS |
556 | /* mov r11, imm32 */ |
557 | EMIT3_off32(0x49, 0xC7, 0xC3, imm32); | |
62258278 | 558 | |
e430f34e AS |
559 | /* mov rax, dst_reg */ |
560 | EMIT_mov(BPF_REG_0, dst_reg); | |
62258278 | 561 | |
a2c7a983 IM |
562 | /* |
563 | * xor edx, edx | |
62258278 AS |
564 | * equivalent to 'xor rdx, rdx', but one byte less |
565 | */ | |
566 | EMIT2(0x31, 0xd2); | |
567 | ||
62258278 AS |
568 | if (BPF_CLASS(insn->code) == BPF_ALU64) |
569 | /* div r11 */ | |
570 | EMIT3(0x49, 0xF7, 0xF3); | |
571 | else | |
572 | /* div r11d */ | |
573 | EMIT3(0x41, 0xF7, 0xF3); | |
574 | ||
575 | if (BPF_OP(insn->code) == BPF_MOD) | |
576 | /* mov r11, rdx */ | |
577 | EMIT3(0x49, 0x89, 0xD3); | |
578 | else | |
579 | /* mov r11, rax */ | |
580 | EMIT3(0x49, 0x89, 0xC3); | |
581 | ||
582 | EMIT1(0x5A); /* pop rdx */ | |
583 | EMIT1(0x58); /* pop rax */ | |
584 | ||
e430f34e AS |
585 | /* mov dst_reg, r11 */ |
586 | EMIT_mov(dst_reg, AUX_REG); | |
62258278 AS |
587 | break; |
588 | ||
589 | case BPF_ALU | BPF_MUL | BPF_K: | |
590 | case BPF_ALU | BPF_MUL | BPF_X: | |
591 | case BPF_ALU64 | BPF_MUL | BPF_K: | |
592 | case BPF_ALU64 | BPF_MUL | BPF_X: | |
4c38e2f3 DB |
593 | { |
594 | bool is64 = BPF_CLASS(insn->code) == BPF_ALU64; | |
595 | ||
d806a0cf DB |
596 | if (dst_reg != BPF_REG_0) |
597 | EMIT1(0x50); /* push rax */ | |
598 | if (dst_reg != BPF_REG_3) | |
599 | EMIT1(0x52); /* push rdx */ | |
62258278 | 600 | |
e430f34e AS |
601 | /* mov r11, dst_reg */ |
602 | EMIT_mov(AUX_REG, dst_reg); | |
62258278 AS |
603 | |
604 | if (BPF_SRC(insn->code) == BPF_X) | |
4c38e2f3 | 605 | emit_mov_reg(&prog, is64, BPF_REG_0, src_reg); |
62258278 | 606 | else |
4c38e2f3 | 607 | emit_mov_imm32(&prog, is64, BPF_REG_0, imm32); |
62258278 | 608 | |
4c38e2f3 | 609 | if (is64) |
62258278 AS |
610 | EMIT1(add_1mod(0x48, AUX_REG)); |
611 | else if (is_ereg(AUX_REG)) | |
612 | EMIT1(add_1mod(0x40, AUX_REG)); | |
613 | /* mul(q) r11 */ | |
614 | EMIT2(0xF7, add_1reg(0xE0, AUX_REG)); | |
615 | ||
d806a0cf DB |
616 | if (dst_reg != BPF_REG_3) |
617 | EMIT1(0x5A); /* pop rdx */ | |
618 | if (dst_reg != BPF_REG_0) { | |
619 | /* mov dst_reg, rax */ | |
620 | EMIT_mov(dst_reg, BPF_REG_0); | |
621 | EMIT1(0x58); /* pop rax */ | |
622 | } | |
62258278 | 623 | break; |
4c38e2f3 | 624 | } |
a2c7a983 | 625 | /* Shifts */ |
62258278 AS |
626 | case BPF_ALU | BPF_LSH | BPF_K: |
627 | case BPF_ALU | BPF_RSH | BPF_K: | |
628 | case BPF_ALU | BPF_ARSH | BPF_K: | |
629 | case BPF_ALU64 | BPF_LSH | BPF_K: | |
630 | case BPF_ALU64 | BPF_RSH | BPF_K: | |
631 | case BPF_ALU64 | BPF_ARSH | BPF_K: | |
632 | if (BPF_CLASS(insn->code) == BPF_ALU64) | |
e430f34e AS |
633 | EMIT1(add_1mod(0x48, dst_reg)); |
634 | else if (is_ereg(dst_reg)) | |
635 | EMIT1(add_1mod(0x40, dst_reg)); | |
62258278 AS |
636 | |
637 | switch (BPF_OP(insn->code)) { | |
638 | case BPF_LSH: b3 = 0xE0; break; | |
639 | case BPF_RSH: b3 = 0xE8; break; | |
640 | case BPF_ARSH: b3 = 0xF8; break; | |
641 | } | |
88e69a1f DB |
642 | |
643 | if (imm32 == 1) | |
644 | EMIT2(0xD1, add_1reg(b3, dst_reg)); | |
645 | else | |
646 | EMIT3(0xC1, add_1reg(b3, dst_reg), imm32); | |
62258278 AS |
647 | break; |
648 | ||
72b603ee AS |
649 | case BPF_ALU | BPF_LSH | BPF_X: |
650 | case BPF_ALU | BPF_RSH | BPF_X: | |
651 | case BPF_ALU | BPF_ARSH | BPF_X: | |
652 | case BPF_ALU64 | BPF_LSH | BPF_X: | |
653 | case BPF_ALU64 | BPF_RSH | BPF_X: | |
654 | case BPF_ALU64 | BPF_ARSH | BPF_X: | |
655 | ||
a2c7a983 | 656 | /* Check for bad case when dst_reg == rcx */ |
72b603ee AS |
657 | if (dst_reg == BPF_REG_4) { |
658 | /* mov r11, dst_reg */ | |
659 | EMIT_mov(AUX_REG, dst_reg); | |
660 | dst_reg = AUX_REG; | |
661 | } | |
662 | ||
663 | if (src_reg != BPF_REG_4) { /* common case */ | |
664 | EMIT1(0x51); /* push rcx */ | |
665 | ||
666 | /* mov rcx, src_reg */ | |
667 | EMIT_mov(BPF_REG_4, src_reg); | |
668 | } | |
669 | ||
670 | /* shl %rax, %cl | shr %rax, %cl | sar %rax, %cl */ | |
671 | if (BPF_CLASS(insn->code) == BPF_ALU64) | |
672 | EMIT1(add_1mod(0x48, dst_reg)); | |
673 | else if (is_ereg(dst_reg)) | |
674 | EMIT1(add_1mod(0x40, dst_reg)); | |
675 | ||
676 | switch (BPF_OP(insn->code)) { | |
677 | case BPF_LSH: b3 = 0xE0; break; | |
678 | case BPF_RSH: b3 = 0xE8; break; | |
679 | case BPF_ARSH: b3 = 0xF8; break; | |
680 | } | |
681 | EMIT2(0xD3, add_1reg(b3, dst_reg)); | |
682 | ||
683 | if (src_reg != BPF_REG_4) | |
684 | EMIT1(0x59); /* pop rcx */ | |
685 | ||
686 | if (insn->dst_reg == BPF_REG_4) | |
687 | /* mov dst_reg, r11 */ | |
688 | EMIT_mov(insn->dst_reg, AUX_REG); | |
689 | break; | |
690 | ||
62258278 | 691 | case BPF_ALU | BPF_END | BPF_FROM_BE: |
e430f34e | 692 | switch (imm32) { |
62258278 | 693 | case 16: |
a2c7a983 | 694 | /* Emit 'ror %ax, 8' to swap lower 2 bytes */ |
62258278 | 695 | EMIT1(0x66); |
e430f34e | 696 | if (is_ereg(dst_reg)) |
62258278 | 697 | EMIT1(0x41); |
e430f34e | 698 | EMIT3(0xC1, add_1reg(0xC8, dst_reg), 8); |
343f845b | 699 | |
a2c7a983 | 700 | /* Emit 'movzwl eax, ax' */ |
343f845b AS |
701 | if (is_ereg(dst_reg)) |
702 | EMIT3(0x45, 0x0F, 0xB7); | |
703 | else | |
704 | EMIT2(0x0F, 0xB7); | |
705 | EMIT1(add_2reg(0xC0, dst_reg, dst_reg)); | |
62258278 AS |
706 | break; |
707 | case 32: | |
a2c7a983 | 708 | /* Emit 'bswap eax' to swap lower 4 bytes */ |
e430f34e | 709 | if (is_ereg(dst_reg)) |
62258278 | 710 | EMIT2(0x41, 0x0F); |
0a14842f | 711 | else |
62258278 | 712 | EMIT1(0x0F); |
e430f34e | 713 | EMIT1(add_1reg(0xC8, dst_reg)); |
0a14842f | 714 | break; |
62258278 | 715 | case 64: |
a2c7a983 | 716 | /* Emit 'bswap rax' to swap 8 bytes */ |
e430f34e AS |
717 | EMIT3(add_1mod(0x48, dst_reg), 0x0F, |
718 | add_1reg(0xC8, dst_reg)); | |
3b58908a ED |
719 | break; |
720 | } | |
62258278 AS |
721 | break; |
722 | ||
723 | case BPF_ALU | BPF_END | BPF_FROM_LE: | |
343f845b AS |
724 | switch (imm32) { |
725 | case 16: | |
a2c7a983 IM |
726 | /* |
727 | * Emit 'movzwl eax, ax' to zero extend 16-bit | |
343f845b AS |
728 | * into 64 bit |
729 | */ | |
730 | if (is_ereg(dst_reg)) | |
731 | EMIT3(0x45, 0x0F, 0xB7); | |
732 | else | |
733 | EMIT2(0x0F, 0xB7); | |
734 | EMIT1(add_2reg(0xC0, dst_reg, dst_reg)); | |
735 | break; | |
736 | case 32: | |
a2c7a983 | 737 | /* Emit 'mov eax, eax' to clear upper 32-bits */ |
343f845b AS |
738 | if (is_ereg(dst_reg)) |
739 | EMIT1(0x45); | |
740 | EMIT2(0x89, add_2reg(0xC0, dst_reg, dst_reg)); | |
741 | break; | |
742 | case 64: | |
743 | /* nop */ | |
744 | break; | |
745 | } | |
62258278 AS |
746 | break; |
747 | ||
e430f34e | 748 | /* ST: *(u8*)(dst_reg + off) = imm */ |
62258278 | 749 | case BPF_ST | BPF_MEM | BPF_B: |
e430f34e | 750 | if (is_ereg(dst_reg)) |
62258278 AS |
751 | EMIT2(0x41, 0xC6); |
752 | else | |
753 | EMIT1(0xC6); | |
754 | goto st; | |
755 | case BPF_ST | BPF_MEM | BPF_H: | |
e430f34e | 756 | if (is_ereg(dst_reg)) |
62258278 AS |
757 | EMIT3(0x66, 0x41, 0xC7); |
758 | else | |
759 | EMIT2(0x66, 0xC7); | |
760 | goto st; | |
761 | case BPF_ST | BPF_MEM | BPF_W: | |
e430f34e | 762 | if (is_ereg(dst_reg)) |
62258278 AS |
763 | EMIT2(0x41, 0xC7); |
764 | else | |
765 | EMIT1(0xC7); | |
766 | goto st; | |
767 | case BPF_ST | BPF_MEM | BPF_DW: | |
e430f34e | 768 | EMIT2(add_1mod(0x48, dst_reg), 0xC7); |
62258278 AS |
769 | |
770 | st: if (is_imm8(insn->off)) | |
e430f34e | 771 | EMIT2(add_1reg(0x40, dst_reg), insn->off); |
62258278 | 772 | else |
e430f34e | 773 | EMIT1_off32(add_1reg(0x80, dst_reg), insn->off); |
62258278 | 774 | |
e430f34e | 775 | EMIT(imm32, bpf_size_to_x86_bytes(BPF_SIZE(insn->code))); |
62258278 AS |
776 | break; |
777 | ||
e430f34e | 778 | /* STX: *(u8*)(dst_reg + off) = src_reg */ |
62258278 | 779 | case BPF_STX | BPF_MEM | BPF_B: |
a2c7a983 | 780 | /* Emit 'mov byte ptr [rax + off], al' */ |
e430f34e | 781 | if (is_ereg(dst_reg) || is_ereg(src_reg) || |
a2c7a983 | 782 | /* We have to add extra byte for x86 SIL, DIL regs */ |
e430f34e AS |
783 | src_reg == BPF_REG_1 || src_reg == BPF_REG_2) |
784 | EMIT2(add_2mod(0x40, dst_reg, src_reg), 0x88); | |
62258278 AS |
785 | else |
786 | EMIT1(0x88); | |
787 | goto stx; | |
788 | case BPF_STX | BPF_MEM | BPF_H: | |
e430f34e AS |
789 | if (is_ereg(dst_reg) || is_ereg(src_reg)) |
790 | EMIT3(0x66, add_2mod(0x40, dst_reg, src_reg), 0x89); | |
62258278 AS |
791 | else |
792 | EMIT2(0x66, 0x89); | |
793 | goto stx; | |
794 | case BPF_STX | BPF_MEM | BPF_W: | |
e430f34e AS |
795 | if (is_ereg(dst_reg) || is_ereg(src_reg)) |
796 | EMIT2(add_2mod(0x40, dst_reg, src_reg), 0x89); | |
62258278 AS |
797 | else |
798 | EMIT1(0x89); | |
799 | goto stx; | |
800 | case BPF_STX | BPF_MEM | BPF_DW: | |
e430f34e | 801 | EMIT2(add_2mod(0x48, dst_reg, src_reg), 0x89); |
62258278 | 802 | stx: if (is_imm8(insn->off)) |
e430f34e | 803 | EMIT2(add_2reg(0x40, dst_reg, src_reg), insn->off); |
62258278 | 804 | else |
e430f34e | 805 | EMIT1_off32(add_2reg(0x80, dst_reg, src_reg), |
62258278 AS |
806 | insn->off); |
807 | break; | |
808 | ||
e430f34e | 809 | /* LDX: dst_reg = *(u8*)(src_reg + off) */ |
62258278 | 810 | case BPF_LDX | BPF_MEM | BPF_B: |
a2c7a983 | 811 | /* Emit 'movzx rax, byte ptr [rax + off]' */ |
e430f34e | 812 | EMIT3(add_2mod(0x48, src_reg, dst_reg), 0x0F, 0xB6); |
62258278 AS |
813 | goto ldx; |
814 | case BPF_LDX | BPF_MEM | BPF_H: | |
a2c7a983 | 815 | /* Emit 'movzx rax, word ptr [rax + off]' */ |
e430f34e | 816 | EMIT3(add_2mod(0x48, src_reg, dst_reg), 0x0F, 0xB7); |
62258278 AS |
817 | goto ldx; |
818 | case BPF_LDX | BPF_MEM | BPF_W: | |
a2c7a983 | 819 | /* Emit 'mov eax, dword ptr [rax+0x14]' */ |
e430f34e AS |
820 | if (is_ereg(dst_reg) || is_ereg(src_reg)) |
821 | EMIT2(add_2mod(0x40, src_reg, dst_reg), 0x8B); | |
62258278 AS |
822 | else |
823 | EMIT1(0x8B); | |
824 | goto ldx; | |
825 | case BPF_LDX | BPF_MEM | BPF_DW: | |
a2c7a983 | 826 | /* Emit 'mov rax, qword ptr [rax+0x14]' */ |
e430f34e | 827 | EMIT2(add_2mod(0x48, src_reg, dst_reg), 0x8B); |
a2c7a983 IM |
828 | ldx: /* |
829 | * If insn->off == 0 we can save one extra byte, but | |
830 | * special case of x86 R13 which always needs an offset | |
62258278 AS |
831 | * is not worth the hassle |
832 | */ | |
833 | if (is_imm8(insn->off)) | |
e430f34e | 834 | EMIT2(add_2reg(0x40, src_reg, dst_reg), insn->off); |
62258278 | 835 | else |
e430f34e | 836 | EMIT1_off32(add_2reg(0x80, src_reg, dst_reg), |
62258278 AS |
837 | insn->off); |
838 | break; | |
839 | ||
e430f34e | 840 | /* STX XADD: lock *(u32*)(dst_reg + off) += src_reg */ |
62258278 | 841 | case BPF_STX | BPF_XADD | BPF_W: |
a2c7a983 | 842 | /* Emit 'lock add dword ptr [rax + off], eax' */ |
e430f34e AS |
843 | if (is_ereg(dst_reg) || is_ereg(src_reg)) |
844 | EMIT3(0xF0, add_2mod(0x40, dst_reg, src_reg), 0x01); | |
62258278 AS |
845 | else |
846 | EMIT2(0xF0, 0x01); | |
847 | goto xadd; | |
848 | case BPF_STX | BPF_XADD | BPF_DW: | |
e430f34e | 849 | EMIT3(0xF0, add_2mod(0x48, dst_reg, src_reg), 0x01); |
62258278 | 850 | xadd: if (is_imm8(insn->off)) |
e430f34e | 851 | EMIT2(add_2reg(0x40, dst_reg, src_reg), insn->off); |
62258278 | 852 | else |
e430f34e | 853 | EMIT1_off32(add_2reg(0x80, dst_reg, src_reg), |
62258278 AS |
854 | insn->off); |
855 | break; | |
856 | ||
857 | /* call */ | |
858 | case BPF_JMP | BPF_CALL: | |
e430f34e | 859 | func = (u8 *) __bpf_call_base + imm32; |
62258278 | 860 | jmp_offset = func - (image + addrs[i]); |
e430f34e | 861 | if (!imm32 || !is_simm32(jmp_offset)) { |
a2c7a983 | 862 | pr_err("unsupported BPF func %d addr %p image %p\n", |
e430f34e | 863 | imm32, func, image); |
62258278 AS |
864 | return -EINVAL; |
865 | } | |
866 | EMIT1_off32(0xE8, jmp_offset); | |
62258278 AS |
867 | break; |
868 | ||
71189fa9 | 869 | case BPF_JMP | BPF_TAIL_CALL: |
b52f00e6 AS |
870 | emit_bpf_tail_call(&prog); |
871 | break; | |
872 | ||
62258278 AS |
873 | /* cond jump */ |
874 | case BPF_JMP | BPF_JEQ | BPF_X: | |
875 | case BPF_JMP | BPF_JNE | BPF_X: | |
876 | case BPF_JMP | BPF_JGT | BPF_X: | |
52afc51e | 877 | case BPF_JMP | BPF_JLT | BPF_X: |
62258278 | 878 | case BPF_JMP | BPF_JGE | BPF_X: |
52afc51e | 879 | case BPF_JMP | BPF_JLE | BPF_X: |
62258278 | 880 | case BPF_JMP | BPF_JSGT | BPF_X: |
52afc51e | 881 | case BPF_JMP | BPF_JSLT | BPF_X: |
62258278 | 882 | case BPF_JMP | BPF_JSGE | BPF_X: |
52afc51e | 883 | case BPF_JMP | BPF_JSLE | BPF_X: |
e430f34e AS |
884 | /* cmp dst_reg, src_reg */ |
885 | EMIT3(add_2mod(0x48, dst_reg, src_reg), 0x39, | |
886 | add_2reg(0xC0, dst_reg, src_reg)); | |
62258278 AS |
887 | goto emit_cond_jmp; |
888 | ||
889 | case BPF_JMP | BPF_JSET | BPF_X: | |
e430f34e AS |
890 | /* test dst_reg, src_reg */ |
891 | EMIT3(add_2mod(0x48, dst_reg, src_reg), 0x85, | |
892 | add_2reg(0xC0, dst_reg, src_reg)); | |
62258278 AS |
893 | goto emit_cond_jmp; |
894 | ||
895 | case BPF_JMP | BPF_JSET | BPF_K: | |
e430f34e AS |
896 | /* test dst_reg, imm32 */ |
897 | EMIT1(add_1mod(0x48, dst_reg)); | |
898 | EMIT2_off32(0xF7, add_1reg(0xC0, dst_reg), imm32); | |
62258278 AS |
899 | goto emit_cond_jmp; |
900 | ||
901 | case BPF_JMP | BPF_JEQ | BPF_K: | |
902 | case BPF_JMP | BPF_JNE | BPF_K: | |
903 | case BPF_JMP | BPF_JGT | BPF_K: | |
52afc51e | 904 | case BPF_JMP | BPF_JLT | BPF_K: |
62258278 | 905 | case BPF_JMP | BPF_JGE | BPF_K: |
52afc51e | 906 | case BPF_JMP | BPF_JLE | BPF_K: |
62258278 | 907 | case BPF_JMP | BPF_JSGT | BPF_K: |
52afc51e | 908 | case BPF_JMP | BPF_JSLT | BPF_K: |
62258278 | 909 | case BPF_JMP | BPF_JSGE | BPF_K: |
52afc51e | 910 | case BPF_JMP | BPF_JSLE | BPF_K: |
e430f34e AS |
911 | /* cmp dst_reg, imm8/32 */ |
912 | EMIT1(add_1mod(0x48, dst_reg)); | |
62258278 | 913 | |
e430f34e AS |
914 | if (is_imm8(imm32)) |
915 | EMIT3(0x83, add_1reg(0xF8, dst_reg), imm32); | |
62258278 | 916 | else |
e430f34e | 917 | EMIT2_off32(0x81, add_1reg(0xF8, dst_reg), imm32); |
62258278 | 918 | |
a2c7a983 | 919 | emit_cond_jmp: /* Convert BPF opcode to x86 */ |
62258278 AS |
920 | switch (BPF_OP(insn->code)) { |
921 | case BPF_JEQ: | |
922 | jmp_cond = X86_JE; | |
923 | break; | |
924 | case BPF_JSET: | |
925 | case BPF_JNE: | |
926 | jmp_cond = X86_JNE; | |
927 | break; | |
928 | case BPF_JGT: | |
929 | /* GT is unsigned '>', JA in x86 */ | |
930 | jmp_cond = X86_JA; | |
931 | break; | |
52afc51e DB |
932 | case BPF_JLT: |
933 | /* LT is unsigned '<', JB in x86 */ | |
934 | jmp_cond = X86_JB; | |
935 | break; | |
62258278 AS |
936 | case BPF_JGE: |
937 | /* GE is unsigned '>=', JAE in x86 */ | |
938 | jmp_cond = X86_JAE; | |
939 | break; | |
52afc51e DB |
940 | case BPF_JLE: |
941 | /* LE is unsigned '<=', JBE in x86 */ | |
942 | jmp_cond = X86_JBE; | |
943 | break; | |
62258278 | 944 | case BPF_JSGT: |
a2c7a983 | 945 | /* Signed '>', GT in x86 */ |
62258278 AS |
946 | jmp_cond = X86_JG; |
947 | break; | |
52afc51e | 948 | case BPF_JSLT: |
a2c7a983 | 949 | /* Signed '<', LT in x86 */ |
52afc51e DB |
950 | jmp_cond = X86_JL; |
951 | break; | |
62258278 | 952 | case BPF_JSGE: |
a2c7a983 | 953 | /* Signed '>=', GE in x86 */ |
62258278 AS |
954 | jmp_cond = X86_JGE; |
955 | break; | |
52afc51e | 956 | case BPF_JSLE: |
a2c7a983 | 957 | /* Signed '<=', LE in x86 */ |
52afc51e DB |
958 | jmp_cond = X86_JLE; |
959 | break; | |
a2c7a983 | 960 | default: /* to silence GCC warning */ |
62258278 AS |
961 | return -EFAULT; |
962 | } | |
963 | jmp_offset = addrs[i + insn->off] - addrs[i]; | |
964 | if (is_imm8(jmp_offset)) { | |
965 | EMIT2(jmp_cond, jmp_offset); | |
966 | } else if (is_simm32(jmp_offset)) { | |
967 | EMIT2_off32(0x0F, jmp_cond + 0x10, jmp_offset); | |
968 | } else { | |
969 | pr_err("cond_jmp gen bug %llx\n", jmp_offset); | |
970 | return -EFAULT; | |
971 | } | |
972 | ||
973 | break; | |
0a14842f | 974 | |
62258278 | 975 | case BPF_JMP | BPF_JA: |
1612a981 GB |
976 | if (insn->off == -1) |
977 | /* -1 jmp instructions will always jump | |
978 | * backwards two bytes. Explicitly handling | |
979 | * this case avoids wasting too many passes | |
980 | * when there are long sequences of replaced | |
981 | * dead code. | |
982 | */ | |
983 | jmp_offset = -2; | |
984 | else | |
985 | jmp_offset = addrs[i + insn->off] - addrs[i]; | |
986 | ||
62258278 | 987 | if (!jmp_offset) |
a2c7a983 | 988 | /* Optimize out nop jumps */ |
62258278 AS |
989 | break; |
990 | emit_jmp: | |
991 | if (is_imm8(jmp_offset)) { | |
992 | EMIT2(0xEB, jmp_offset); | |
993 | } else if (is_simm32(jmp_offset)) { | |
994 | EMIT1_off32(0xE9, jmp_offset); | |
995 | } else { | |
996 | pr_err("jmp gen bug %llx\n", jmp_offset); | |
997 | return -EFAULT; | |
998 | } | |
999 | break; | |
1000 | ||
62258278 | 1001 | case BPF_JMP | BPF_EXIT: |
769e0de6 | 1002 | if (seen_exit) { |
62258278 AS |
1003 | jmp_offset = ctx->cleanup_addr - addrs[i]; |
1004 | goto emit_jmp; | |
1005 | } | |
769e0de6 | 1006 | seen_exit = true; |
a2c7a983 | 1007 | /* Update cleanup_addr */ |
62258278 | 1008 | ctx->cleanup_addr = proglen; |
177366bf AS |
1009 | /* mov rbx, qword ptr [rbp+0] */ |
1010 | EMIT4(0x48, 0x8B, 0x5D, 0); | |
1011 | /* mov r13, qword ptr [rbp+8] */ | |
1012 | EMIT4(0x4C, 0x8B, 0x6D, 8); | |
1013 | /* mov r14, qword ptr [rbp+16] */ | |
1014 | EMIT4(0x4C, 0x8B, 0x75, 16); | |
1015 | /* mov r15, qword ptr [rbp+24] */ | |
1016 | EMIT4(0x4C, 0x8B, 0x7D, 24); | |
1017 | ||
1018 | /* add rbp, AUX_STACK_SPACE */ | |
1019 | EMIT4(0x48, 0x83, 0xC5, AUX_STACK_SPACE); | |
62258278 AS |
1020 | EMIT1(0xC9); /* leave */ |
1021 | EMIT1(0xC3); /* ret */ | |
1022 | break; | |
1023 | ||
f3c2af7b | 1024 | default: |
a2c7a983 IM |
1025 | /* |
1026 | * By design x86-64 JIT should support all BPF instructions. | |
62258278 | 1027 | * This error will be seen if new instruction was added |
a2c7a983 IM |
1028 | * to the interpreter, but not to the JIT, or if there is |
1029 | * junk in bpf_prog. | |
62258278 AS |
1030 | */ |
1031 | pr_err("bpf_jit: unknown opcode %02x\n", insn->code); | |
f3c2af7b AS |
1032 | return -EINVAL; |
1033 | } | |
62258278 | 1034 | |
f3c2af7b | 1035 | ilen = prog - temp; |
e0ee9c12 | 1036 | if (ilen > BPF_MAX_INSN_SIZE) { |
9383191d | 1037 | pr_err("bpf_jit: fatal insn size error\n"); |
e0ee9c12 AS |
1038 | return -EFAULT; |
1039 | } | |
1040 | ||
f3c2af7b AS |
1041 | if (image) { |
1042 | if (unlikely(proglen + ilen > oldproglen)) { | |
9383191d | 1043 | pr_err("bpf_jit: fatal error\n"); |
f3c2af7b | 1044 | return -EFAULT; |
0a14842f | 1045 | } |
f3c2af7b | 1046 | memcpy(image + proglen, temp, ilen); |
0a14842f | 1047 | } |
f3c2af7b AS |
1048 | proglen += ilen; |
1049 | addrs[i] = proglen; | |
1050 | prog = temp; | |
1051 | } | |
f3c2af7b AS |
1052 | return proglen; |
1053 | } | |
1054 | ||
1c2a088a AS |
1055 | struct x64_jit_data { |
1056 | struct bpf_binary_header *header; | |
1057 | int *addrs; | |
1058 | u8 *image; | |
1059 | int proglen; | |
1060 | struct jit_context ctx; | |
1061 | }; | |
1062 | ||
d1c55ab5 | 1063 | struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog) |
f3c2af7b AS |
1064 | { |
1065 | struct bpf_binary_header *header = NULL; | |
959a7579 | 1066 | struct bpf_prog *tmp, *orig_prog = prog; |
1c2a088a | 1067 | struct x64_jit_data *jit_data; |
f3c2af7b AS |
1068 | int proglen, oldproglen = 0; |
1069 | struct jit_context ctx = {}; | |
959a7579 | 1070 | bool tmp_blinded = false; |
1c2a088a | 1071 | bool extra_pass = false; |
f3c2af7b AS |
1072 | u8 *image = NULL; |
1073 | int *addrs; | |
1074 | int pass; | |
1075 | int i; | |
1076 | ||
60b58afc | 1077 | if (!prog->jit_requested) |
959a7579 DB |
1078 | return orig_prog; |
1079 | ||
1080 | tmp = bpf_jit_blind_constants(prog); | |
a2c7a983 IM |
1081 | /* |
1082 | * If blinding was requested and we failed during blinding, | |
959a7579 DB |
1083 | * we must fall back to the interpreter. |
1084 | */ | |
1085 | if (IS_ERR(tmp)) | |
1086 | return orig_prog; | |
1087 | if (tmp != prog) { | |
1088 | tmp_blinded = true; | |
1089 | prog = tmp; | |
1090 | } | |
0a14842f | 1091 | |
1c2a088a AS |
1092 | jit_data = prog->aux->jit_data; |
1093 | if (!jit_data) { | |
1094 | jit_data = kzalloc(sizeof(*jit_data), GFP_KERNEL); | |
1095 | if (!jit_data) { | |
1096 | prog = orig_prog; | |
1097 | goto out; | |
1098 | } | |
1099 | prog->aux->jit_data = jit_data; | |
1100 | } | |
1101 | addrs = jit_data->addrs; | |
1102 | if (addrs) { | |
1103 | ctx = jit_data->ctx; | |
1104 | oldproglen = jit_data->proglen; | |
1105 | image = jit_data->image; | |
1106 | header = jit_data->header; | |
1107 | extra_pass = true; | |
1108 | goto skip_init_addrs; | |
1109 | } | |
6da2ec56 | 1110 | addrs = kmalloc_array(prog->len, sizeof(*addrs), GFP_KERNEL); |
959a7579 DB |
1111 | if (!addrs) { |
1112 | prog = orig_prog; | |
1c2a088a | 1113 | goto out_addrs; |
959a7579 | 1114 | } |
f3c2af7b | 1115 | |
a2c7a983 IM |
1116 | /* |
1117 | * Before first pass, make a rough estimation of addrs[] | |
1118 | * each BPF instruction is translated to less than 64 bytes | |
f3c2af7b AS |
1119 | */ |
1120 | for (proglen = 0, i = 0; i < prog->len; i++) { | |
1121 | proglen += 64; | |
1122 | addrs[i] = proglen; | |
1123 | } | |
1124 | ctx.cleanup_addr = proglen; | |
1c2a088a | 1125 | skip_init_addrs: |
f3c2af7b | 1126 | |
a2c7a983 IM |
1127 | /* |
1128 | * JITed image shrinks with every pass and the loop iterates | |
1129 | * until the image stops shrinking. Very large BPF programs | |
3f7352bf | 1130 | * may converge on the last pass. In such case do one more |
a2c7a983 | 1131 | * pass to emit the final image. |
3f7352bf | 1132 | */ |
6007b080 | 1133 | for (pass = 0; pass < 20 || image; pass++) { |
f3c2af7b AS |
1134 | proglen = do_jit(prog, addrs, image, oldproglen, &ctx); |
1135 | if (proglen <= 0) { | |
3aab8884 | 1136 | out_image: |
f3c2af7b AS |
1137 | image = NULL; |
1138 | if (header) | |
738cbe72 | 1139 | bpf_jit_binary_free(header); |
959a7579 DB |
1140 | prog = orig_prog; |
1141 | goto out_addrs; | |
f3c2af7b | 1142 | } |
0a14842f | 1143 | if (image) { |
e0ee9c12 | 1144 | if (proglen != oldproglen) { |
f3c2af7b AS |
1145 | pr_err("bpf_jit: proglen=%d != oldproglen=%d\n", |
1146 | proglen, oldproglen); | |
3aab8884 | 1147 | goto out_image; |
e0ee9c12 | 1148 | } |
0a14842f ED |
1149 | break; |
1150 | } | |
1151 | if (proglen == oldproglen) { | |
738cbe72 DB |
1152 | header = bpf_jit_binary_alloc(proglen, &image, |
1153 | 1, jit_fill_hole); | |
959a7579 DB |
1154 | if (!header) { |
1155 | prog = orig_prog; | |
1156 | goto out_addrs; | |
1157 | } | |
0a14842f ED |
1158 | } |
1159 | oldproglen = proglen; | |
6007b080 | 1160 | cond_resched(); |
0a14842f | 1161 | } |
79617801 | 1162 | |
0a14842f | 1163 | if (bpf_jit_enable > 1) |
485d6511 | 1164 | bpf_jit_dump(prog->len, proglen, pass + 1, image); |
0a14842f ED |
1165 | |
1166 | if (image) { | |
1c2a088a AS |
1167 | if (!prog->is_func || extra_pass) { |
1168 | bpf_jit_binary_lock_ro(header); | |
1169 | } else { | |
1170 | jit_data->addrs = addrs; | |
1171 | jit_data->ctx = ctx; | |
1172 | jit_data->proglen = proglen; | |
1173 | jit_data->image = image; | |
1174 | jit_data->header = header; | |
1175 | } | |
f3c2af7b | 1176 | prog->bpf_func = (void *)image; |
a91263d5 | 1177 | prog->jited = 1; |
783d28dd | 1178 | prog->jited_len = proglen; |
9d5ecb09 DB |
1179 | } else { |
1180 | prog = orig_prog; | |
0a14842f | 1181 | } |
959a7579 | 1182 | |
39f56ca9 | 1183 | if (!image || !prog->is_func || extra_pass) { |
959a7579 | 1184 | out_addrs: |
1c2a088a AS |
1185 | kfree(addrs); |
1186 | kfree(jit_data); | |
1187 | prog->aux->jit_data = NULL; | |
1188 | } | |
959a7579 DB |
1189 | out: |
1190 | if (tmp_blinded) | |
1191 | bpf_jit_prog_release_other(prog, prog == orig_prog ? | |
1192 | tmp : orig_prog); | |
d1c55ab5 | 1193 | return prog; |
0a14842f | 1194 | } |