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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> |
a493a87f | 16 | #include <asm/nospec-branch.h> |
b52f00e6 | 17 | #include <linux/bpf.h> |
0a14842f | 18 | |
0a14842f ED |
19 | /* |
20 | * assembly code in arch/x86/net/bpf_jit.S | |
21 | */ | |
62258278 | 22 | extern u8 sk_load_word[], sk_load_half[], sk_load_byte[]; |
a998d434 | 23 | extern u8 sk_load_word_positive_offset[], sk_load_half_positive_offset[]; |
62258278 | 24 | extern u8 sk_load_byte_positive_offset[]; |
a998d434 | 25 | extern u8 sk_load_word_negative_offset[], sk_load_half_negative_offset[]; |
62258278 | 26 | extern u8 sk_load_byte_negative_offset[]; |
0a14842f | 27 | |
5cccc702 | 28 | static u8 *emit_code(u8 *ptr, u32 bytes, unsigned int len) |
0a14842f ED |
29 | { |
30 | if (len == 1) | |
31 | *ptr = bytes; | |
32 | else if (len == 2) | |
33 | *(u16 *)ptr = bytes; | |
34 | else { | |
35 | *(u32 *)ptr = bytes; | |
36 | barrier(); | |
37 | } | |
38 | return ptr + len; | |
39 | } | |
40 | ||
b52f00e6 AS |
41 | #define EMIT(bytes, len) \ |
42 | do { prog = emit_code(prog, bytes, len); cnt += len; } while (0) | |
0a14842f ED |
43 | |
44 | #define EMIT1(b1) EMIT(b1, 1) | |
45 | #define EMIT2(b1, b2) EMIT((b1) + ((b2) << 8), 2) | |
46 | #define EMIT3(b1, b2, b3) EMIT((b1) + ((b2) << 8) + ((b3) << 16), 3) | |
47 | #define EMIT4(b1, b2, b3, b4) EMIT((b1) + ((b2) << 8) + ((b3) << 16) + ((b4) << 24), 4) | |
62258278 AS |
48 | #define EMIT1_off32(b1, off) \ |
49 | do {EMIT1(b1); EMIT(off, 4); } while (0) | |
50 | #define EMIT2_off32(b1, b2, off) \ | |
51 | do {EMIT2(b1, b2); EMIT(off, 4); } while (0) | |
52 | #define EMIT3_off32(b1, b2, b3, off) \ | |
53 | do {EMIT3(b1, b2, b3); EMIT(off, 4); } while (0) | |
54 | #define EMIT4_off32(b1, b2, b3, b4, off) \ | |
55 | do {EMIT4(b1, b2, b3, b4); EMIT(off, 4); } while (0) | |
0a14842f | 56 | |
5cccc702 | 57 | static bool is_imm8(int value) |
0a14842f ED |
58 | { |
59 | return value <= 127 && value >= -128; | |
60 | } | |
61 | ||
5cccc702 | 62 | static bool is_simm32(s64 value) |
0a14842f | 63 | { |
62258278 | 64 | return value == (s64) (s32) value; |
0a14842f ED |
65 | } |
66 | ||
e430f34e AS |
67 | /* mov dst, src */ |
68 | #define EMIT_mov(DST, SRC) \ | |
69 | do {if (DST != SRC) \ | |
70 | EMIT3(add_2mod(0x48, DST, SRC), 0x89, add_2reg(0xC0, DST, SRC)); \ | |
62258278 AS |
71 | } while (0) |
72 | ||
73 | static int bpf_size_to_x86_bytes(int bpf_size) | |
74 | { | |
75 | if (bpf_size == BPF_W) | |
76 | return 4; | |
77 | else if (bpf_size == BPF_H) | |
78 | return 2; | |
79 | else if (bpf_size == BPF_B) | |
80 | return 1; | |
81 | else if (bpf_size == BPF_DW) | |
82 | return 4; /* imm32 */ | |
83 | else | |
84 | return 0; | |
85 | } | |
0a14842f ED |
86 | |
87 | /* list of x86 cond jumps opcodes (. + s8) | |
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 | |
5cccc702 | 101 | static void bpf_flush_icache(void *start, void *end) |
0a14842f ED |
102 | { |
103 | mm_segment_t old_fs = get_fs(); | |
104 | ||
105 | set_fs(KERNEL_DS); | |
106 | smp_wmb(); | |
107 | flush_icache_range((unsigned long)start, (unsigned long)end); | |
108 | set_fs(old_fs); | |
109 | } | |
110 | ||
a998d434 JS |
111 | #define CHOOSE_LOAD_FUNC(K, func) \ |
112 | ((int)K < 0 ? ((int)K >= SKF_LL_OFF ? func##_negative_offset : func) : func##_positive_offset) | |
0a14842f | 113 | |
62258278 | 114 | /* pick a register outside of BPF range for JIT internal work */ |
959a7579 | 115 | #define AUX_REG (MAX_BPF_JIT_REG + 1) |
62258278 | 116 | |
959a7579 DB |
117 | /* The following table maps BPF registers to x64 registers. |
118 | * | |
119 | * x64 register r12 is unused, since if used as base address | |
120 | * register in load/store instructions, it always needs an | |
121 | * extra byte of encoding and is callee saved. | |
122 | * | |
123 | * r9 caches skb->len - skb->data_len | |
124 | * r10 caches skb->data, and used for blinding (if enabled) | |
62258278 AS |
125 | */ |
126 | static const int reg2hex[] = { | |
127 | [BPF_REG_0] = 0, /* rax */ | |
128 | [BPF_REG_1] = 7, /* rdi */ | |
129 | [BPF_REG_2] = 6, /* rsi */ | |
130 | [BPF_REG_3] = 2, /* rdx */ | |
131 | [BPF_REG_4] = 1, /* rcx */ | |
132 | [BPF_REG_5] = 0, /* r8 */ | |
133 | [BPF_REG_6] = 3, /* rbx callee saved */ | |
134 | [BPF_REG_7] = 5, /* r13 callee saved */ | |
135 | [BPF_REG_8] = 6, /* r14 callee saved */ | |
136 | [BPF_REG_9] = 7, /* r15 callee saved */ | |
137 | [BPF_REG_FP] = 5, /* rbp readonly */ | |
959a7579 | 138 | [BPF_REG_AX] = 2, /* r10 temp register */ |
62258278 AS |
139 | [AUX_REG] = 3, /* r11 temp register */ |
140 | }; | |
141 | ||
142 | /* is_ereg() == true if BPF register 'reg' maps to x64 r8..r15 | |
143 | * which need extra byte of encoding. | |
144 | * rax,rcx,...,rbp have simpler encoding | |
145 | */ | |
5cccc702 | 146 | static bool is_ereg(u32 reg) |
62258278 | 147 | { |
d148134b JP |
148 | return (1 << reg) & (BIT(BPF_REG_5) | |
149 | BIT(AUX_REG) | | |
150 | BIT(BPF_REG_7) | | |
151 | BIT(BPF_REG_8) | | |
959a7579 DB |
152 | BIT(BPF_REG_9) | |
153 | BIT(BPF_REG_AX)); | |
62258278 AS |
154 | } |
155 | ||
de0a444d DB |
156 | static bool is_axreg(u32 reg) |
157 | { | |
158 | return reg == BPF_REG_0; | |
159 | } | |
160 | ||
62258278 | 161 | /* add modifiers if 'reg' maps to x64 registers r8..r15 */ |
5cccc702 | 162 | static u8 add_1mod(u8 byte, u32 reg) |
62258278 AS |
163 | { |
164 | if (is_ereg(reg)) | |
165 | byte |= 1; | |
166 | return byte; | |
167 | } | |
168 | ||
5cccc702 | 169 | static u8 add_2mod(u8 byte, u32 r1, u32 r2) |
62258278 AS |
170 | { |
171 | if (is_ereg(r1)) | |
172 | byte |= 1; | |
173 | if (is_ereg(r2)) | |
174 | byte |= 4; | |
175 | return byte; | |
176 | } | |
177 | ||
e430f34e | 178 | /* encode 'dst_reg' register into x64 opcode 'byte' */ |
5cccc702 | 179 | static u8 add_1reg(u8 byte, u32 dst_reg) |
62258278 | 180 | { |
e430f34e | 181 | return byte + reg2hex[dst_reg]; |
62258278 AS |
182 | } |
183 | ||
e430f34e | 184 | /* encode 'dst_reg' and 'src_reg' registers into x64 opcode 'byte' */ |
5cccc702 | 185 | static u8 add_2reg(u8 byte, u32 dst_reg, u32 src_reg) |
62258278 | 186 | { |
e430f34e | 187 | return byte + reg2hex[dst_reg] + (reg2hex[src_reg] << 3); |
62258278 AS |
188 | } |
189 | ||
738cbe72 DB |
190 | static void jit_fill_hole(void *area, unsigned int size) |
191 | { | |
192 | /* fill whole space with int3 instructions */ | |
193 | memset(area, 0xcc, size); | |
194 | } | |
195 | ||
f3c2af7b | 196 | struct jit_context { |
769e0de6 | 197 | int cleanup_addr; /* epilogue code offset */ |
62258278 | 198 | bool seen_ld_abs; |
959a7579 | 199 | bool seen_ax_reg; |
f3c2af7b AS |
200 | }; |
201 | ||
e0ee9c12 AS |
202 | /* maximum number of bytes emitted while JITing one eBPF insn */ |
203 | #define BPF_MAX_INSN_SIZE 128 | |
204 | #define BPF_INSN_SAFETY 64 | |
205 | ||
177366bf AS |
206 | #define AUX_STACK_SPACE \ |
207 | (32 /* space for rbx, r13, r14, r15 */ + \ | |
b52f00e6 AS |
208 | 8 /* space for skb_copy_bits() buffer */) |
209 | ||
177366bf | 210 | #define PROLOGUE_SIZE 37 |
b52f00e6 AS |
211 | |
212 | /* emit x64 prologue code for BPF program and check it's size. | |
213 | * bpf_tail_call helper will skip it while jumping into another program | |
214 | */ | |
2960ae48 | 215 | static void emit_prologue(u8 **pprog, u32 stack_depth) |
0a14842f | 216 | { |
b52f00e6 AS |
217 | u8 *prog = *pprog; |
218 | int cnt = 0; | |
0a14842f | 219 | |
62258278 AS |
220 | EMIT1(0x55); /* push rbp */ |
221 | EMIT3(0x48, 0x89, 0xE5); /* mov rbp,rsp */ | |
0a14842f | 222 | |
2960ae48 AS |
223 | /* sub rsp, rounded_stack_depth + AUX_STACK_SPACE */ |
224 | EMIT3_off32(0x48, 0x81, 0xEC, | |
225 | round_up(stack_depth, 8) + AUX_STACK_SPACE); | |
177366bf AS |
226 | |
227 | /* sub rbp, AUX_STACK_SPACE */ | |
228 | EMIT4(0x48, 0x83, 0xED, AUX_STACK_SPACE); | |
62258278 AS |
229 | |
230 | /* all classic BPF filters use R6(rbx) save it */ | |
231 | ||
177366bf AS |
232 | /* mov qword ptr [rbp+0],rbx */ |
233 | EMIT4(0x48, 0x89, 0x5D, 0); | |
62258278 | 234 | |
8fb575ca | 235 | /* bpf_convert_filter() maps classic BPF register X to R7 and uses R8 |
62258278 AS |
236 | * as temporary, so all tcpdump filters need to spill/fill R7(r13) and |
237 | * R8(r14). R9(r15) spill could be made conditional, but there is only | |
238 | * one 'bpf_error' return path out of helper functions inside bpf_jit.S | |
239 | * The overhead of extra spill is negligible for any filter other | |
240 | * than synthetic ones. Therefore not worth adding complexity. | |
241 | */ | |
242 | ||
177366bf AS |
243 | /* mov qword ptr [rbp+8],r13 */ |
244 | EMIT4(0x4C, 0x89, 0x6D, 8); | |
245 | /* mov qword ptr [rbp+16],r14 */ | |
246 | EMIT4(0x4C, 0x89, 0x75, 16); | |
247 | /* mov qword ptr [rbp+24],r15 */ | |
248 | EMIT4(0x4C, 0x89, 0x7D, 24); | |
62258278 | 249 | |
8b614aeb DB |
250 | /* Clear the tail call counter (tail_call_cnt): for eBPF tail calls |
251 | * we need to reset the counter to 0. It's done in two instructions, | |
252 | * resetting rax register to 0 (xor on eax gets 0 extended), and | |
253 | * moving it to the counter location. | |
254 | */ | |
62258278 | 255 | |
8b614aeb DB |
256 | /* xor eax, eax */ |
257 | EMIT2(0x31, 0xc0); | |
177366bf AS |
258 | /* mov qword ptr [rbp+32], rax */ |
259 | EMIT4(0x48, 0x89, 0x45, 32); | |
b52f00e6 AS |
260 | |
261 | BUILD_BUG_ON(cnt != PROLOGUE_SIZE); | |
262 | *pprog = prog; | |
263 | } | |
264 | ||
265 | /* generate the following code: | |
266 | * ... bpf_tail_call(void *ctx, struct bpf_array *array, u64 index) ... | |
267 | * if (index >= array->map.max_entries) | |
268 | * goto out; | |
269 | * if (++tail_call_cnt > MAX_TAIL_CALL_CNT) | |
270 | * goto out; | |
2a36f0b9 | 271 | * prog = array->ptrs[index]; |
b52f00e6 AS |
272 | * if (prog == NULL) |
273 | * goto out; | |
274 | * goto *(prog->bpf_func + prologue_size); | |
275 | * out: | |
276 | */ | |
277 | static void emit_bpf_tail_call(u8 **pprog) | |
278 | { | |
279 | u8 *prog = *pprog; | |
280 | int label1, label2, label3; | |
281 | int cnt = 0; | |
282 | ||
283 | /* rdi - pointer to ctx | |
284 | * rsi - pointer to bpf_array | |
285 | * rdx - index in bpf_array | |
286 | */ | |
287 | ||
288 | /* if (index >= array->map.max_entries) | |
289 | * goto out; | |
290 | */ | |
90caccdd AS |
291 | EMIT2(0x89, 0xD2); /* mov edx, edx */ |
292 | EMIT3(0x39, 0x56, /* cmp dword ptr [rsi + 16], edx */ | |
b52f00e6 | 293 | offsetof(struct bpf_array, map.max_entries)); |
a493a87f | 294 | #define OFFSET1 (41 + RETPOLINE_RAX_BPF_JIT_SIZE) /* number of bytes to jump */ |
b52f00e6 AS |
295 | EMIT2(X86_JBE, OFFSET1); /* jbe out */ |
296 | label1 = cnt; | |
297 | ||
298 | /* if (tail_call_cnt > MAX_TAIL_CALL_CNT) | |
299 | * goto out; | |
300 | */ | |
177366bf | 301 | EMIT2_off32(0x8B, 0x85, 36); /* mov eax, dword ptr [rbp + 36] */ |
b52f00e6 | 302 | EMIT3(0x83, 0xF8, MAX_TAIL_CALL_CNT); /* cmp eax, MAX_TAIL_CALL_CNT */ |
a493a87f | 303 | #define OFFSET2 (30 + RETPOLINE_RAX_BPF_JIT_SIZE) |
b52f00e6 AS |
304 | EMIT2(X86_JA, OFFSET2); /* ja out */ |
305 | label2 = cnt; | |
306 | EMIT3(0x83, 0xC0, 0x01); /* add eax, 1 */ | |
177366bf | 307 | EMIT2_off32(0x89, 0x85, 36); /* mov dword ptr [rbp + 36], eax */ |
b52f00e6 | 308 | |
2a36f0b9 | 309 | /* prog = array->ptrs[index]; */ |
84ccac6e | 310 | EMIT4_off32(0x48, 0x8B, 0x84, 0xD6, /* mov rax, [rsi + rdx * 8 + offsetof(...)] */ |
2a36f0b9 | 311 | offsetof(struct bpf_array, ptrs)); |
b52f00e6 AS |
312 | |
313 | /* if (prog == NULL) | |
314 | * goto out; | |
315 | */ | |
84ccac6e | 316 | EMIT3(0x48, 0x85, 0xC0); /* test rax,rax */ |
a493a87f | 317 | #define OFFSET3 (8 + RETPOLINE_RAX_BPF_JIT_SIZE) |
b52f00e6 AS |
318 | EMIT2(X86_JE, OFFSET3); /* je out */ |
319 | label3 = cnt; | |
320 | ||
321 | /* goto *(prog->bpf_func + prologue_size); */ | |
322 | EMIT4(0x48, 0x8B, 0x40, /* mov rax, qword ptr [rax + 32] */ | |
323 | offsetof(struct bpf_prog, bpf_func)); | |
324 | EMIT4(0x48, 0x83, 0xC0, PROLOGUE_SIZE); /* add rax, prologue_size */ | |
325 | ||
326 | /* now we're ready to jump into next BPF program | |
327 | * rdi == ctx (1st arg) | |
328 | * rax == prog->bpf_func + prologue_size | |
329 | */ | |
a493a87f | 330 | RETPOLINE_RAX_BPF_JIT(); |
b52f00e6 AS |
331 | |
332 | /* out: */ | |
333 | BUILD_BUG_ON(cnt - label1 != OFFSET1); | |
334 | BUILD_BUG_ON(cnt - label2 != OFFSET2); | |
335 | BUILD_BUG_ON(cnt - label3 != OFFSET3); | |
336 | *pprog = prog; | |
337 | } | |
338 | ||
4e10df9a AS |
339 | |
340 | static void emit_load_skb_data_hlen(u8 **pprog) | |
341 | { | |
342 | u8 *prog = *pprog; | |
343 | int cnt = 0; | |
344 | ||
345 | /* r9d = skb->len - skb->data_len (headlen) | |
346 | * r10 = skb->data | |
347 | */ | |
348 | /* mov %r9d, off32(%rdi) */ | |
349 | EMIT3_off32(0x44, 0x8b, 0x8f, offsetof(struct sk_buff, len)); | |
350 | ||
351 | /* sub %r9d, off32(%rdi) */ | |
352 | EMIT3_off32(0x44, 0x2b, 0x8f, offsetof(struct sk_buff, data_len)); | |
353 | ||
354 | /* mov %r10, off32(%rdi) */ | |
355 | EMIT3_off32(0x4c, 0x8b, 0x97, offsetof(struct sk_buff, data)); | |
356 | *pprog = prog; | |
357 | } | |
358 | ||
b52f00e6 AS |
359 | static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image, |
360 | int oldproglen, struct jit_context *ctx) | |
361 | { | |
362 | struct bpf_insn *insn = bpf_prog->insnsi; | |
363 | int insn_cnt = bpf_prog->len; | |
364 | bool seen_ld_abs = ctx->seen_ld_abs | (oldproglen == 0); | |
959a7579 | 365 | bool seen_ax_reg = ctx->seen_ax_reg | (oldproglen == 0); |
b52f00e6 AS |
366 | bool seen_exit = false; |
367 | u8 temp[BPF_MAX_INSN_SIZE + BPF_INSN_SAFETY]; | |
368 | int i, cnt = 0; | |
369 | int proglen = 0; | |
370 | u8 *prog = temp; | |
371 | ||
2960ae48 | 372 | emit_prologue(&prog, bpf_prog->aux->stack_depth); |
b52f00e6 | 373 | |
4e10df9a AS |
374 | if (seen_ld_abs) |
375 | emit_load_skb_data_hlen(&prog); | |
62258278 AS |
376 | |
377 | for (i = 0; i < insn_cnt; i++, insn++) { | |
e430f34e AS |
378 | const s32 imm32 = insn->imm; |
379 | u32 dst_reg = insn->dst_reg; | |
380 | u32 src_reg = insn->src_reg; | |
62258278 AS |
381 | u8 b1 = 0, b2 = 0, b3 = 0; |
382 | s64 jmp_offset; | |
383 | u8 jmp_cond; | |
4e10df9a | 384 | bool reload_skb_data; |
62258278 AS |
385 | int ilen; |
386 | u8 *func; | |
387 | ||
959a7579 DB |
388 | if (dst_reg == BPF_REG_AX || src_reg == BPF_REG_AX) |
389 | ctx->seen_ax_reg = seen_ax_reg = true; | |
390 | ||
62258278 AS |
391 | switch (insn->code) { |
392 | /* ALU */ | |
393 | case BPF_ALU | BPF_ADD | BPF_X: | |
394 | case BPF_ALU | BPF_SUB | BPF_X: | |
395 | case BPF_ALU | BPF_AND | BPF_X: | |
396 | case BPF_ALU | BPF_OR | BPF_X: | |
397 | case BPF_ALU | BPF_XOR | BPF_X: | |
398 | case BPF_ALU64 | BPF_ADD | BPF_X: | |
399 | case BPF_ALU64 | BPF_SUB | BPF_X: | |
400 | case BPF_ALU64 | BPF_AND | BPF_X: | |
401 | case BPF_ALU64 | BPF_OR | BPF_X: | |
402 | case BPF_ALU64 | BPF_XOR | BPF_X: | |
403 | switch (BPF_OP(insn->code)) { | |
404 | case BPF_ADD: b2 = 0x01; break; | |
405 | case BPF_SUB: b2 = 0x29; break; | |
406 | case BPF_AND: b2 = 0x21; break; | |
407 | case BPF_OR: b2 = 0x09; break; | |
408 | case BPF_XOR: b2 = 0x31; break; | |
0a14842f | 409 | } |
62258278 | 410 | if (BPF_CLASS(insn->code) == BPF_ALU64) |
e430f34e AS |
411 | EMIT1(add_2mod(0x48, dst_reg, src_reg)); |
412 | else if (is_ereg(dst_reg) || is_ereg(src_reg)) | |
413 | EMIT1(add_2mod(0x40, dst_reg, src_reg)); | |
414 | EMIT2(b2, add_2reg(0xC0, dst_reg, src_reg)); | |
62258278 | 415 | break; |
0a14842f | 416 | |
e430f34e | 417 | /* mov dst, src */ |
62258278 | 418 | case BPF_ALU64 | BPF_MOV | BPF_X: |
e430f34e | 419 | EMIT_mov(dst_reg, src_reg); |
0a14842f | 420 | break; |
0a14842f | 421 | |
e430f34e | 422 | /* mov32 dst, src */ |
62258278 | 423 | case BPF_ALU | BPF_MOV | BPF_X: |
e430f34e AS |
424 | if (is_ereg(dst_reg) || is_ereg(src_reg)) |
425 | EMIT1(add_2mod(0x40, dst_reg, src_reg)); | |
426 | EMIT2(0x89, add_2reg(0xC0, dst_reg, src_reg)); | |
62258278 | 427 | break; |
0a14842f | 428 | |
e430f34e | 429 | /* neg dst */ |
62258278 AS |
430 | case BPF_ALU | BPF_NEG: |
431 | case BPF_ALU64 | BPF_NEG: | |
432 | if (BPF_CLASS(insn->code) == BPF_ALU64) | |
e430f34e AS |
433 | EMIT1(add_1mod(0x48, dst_reg)); |
434 | else if (is_ereg(dst_reg)) | |
435 | EMIT1(add_1mod(0x40, dst_reg)); | |
436 | EMIT2(0xF7, add_1reg(0xD8, dst_reg)); | |
62258278 AS |
437 | break; |
438 | ||
439 | case BPF_ALU | BPF_ADD | BPF_K: | |
440 | case BPF_ALU | BPF_SUB | BPF_K: | |
441 | case BPF_ALU | BPF_AND | BPF_K: | |
442 | case BPF_ALU | BPF_OR | BPF_K: | |
443 | case BPF_ALU | BPF_XOR | BPF_K: | |
444 | case BPF_ALU64 | BPF_ADD | BPF_K: | |
445 | case BPF_ALU64 | BPF_SUB | BPF_K: | |
446 | case BPF_ALU64 | BPF_AND | BPF_K: | |
447 | case BPF_ALU64 | BPF_OR | BPF_K: | |
448 | case BPF_ALU64 | BPF_XOR | BPF_K: | |
449 | if (BPF_CLASS(insn->code) == BPF_ALU64) | |
e430f34e AS |
450 | EMIT1(add_1mod(0x48, dst_reg)); |
451 | else if (is_ereg(dst_reg)) | |
452 | EMIT1(add_1mod(0x40, dst_reg)); | |
62258278 | 453 | |
de0a444d DB |
454 | /* b3 holds 'normal' opcode, b2 short form only valid |
455 | * in case dst is eax/rax. | |
456 | */ | |
62258278 | 457 | switch (BPF_OP(insn->code)) { |
de0a444d DB |
458 | case BPF_ADD: |
459 | b3 = 0xC0; | |
460 | b2 = 0x05; | |
461 | break; | |
462 | case BPF_SUB: | |
463 | b3 = 0xE8; | |
464 | b2 = 0x2D; | |
465 | break; | |
466 | case BPF_AND: | |
467 | b3 = 0xE0; | |
468 | b2 = 0x25; | |
469 | break; | |
470 | case BPF_OR: | |
471 | b3 = 0xC8; | |
472 | b2 = 0x0D; | |
473 | break; | |
474 | case BPF_XOR: | |
475 | b3 = 0xF0; | |
476 | b2 = 0x35; | |
477 | break; | |
62258278 AS |
478 | } |
479 | ||
e430f34e AS |
480 | if (is_imm8(imm32)) |
481 | EMIT3(0x83, add_1reg(b3, dst_reg), imm32); | |
de0a444d DB |
482 | else if (is_axreg(dst_reg)) |
483 | EMIT1_off32(b2, imm32); | |
62258278 | 484 | else |
e430f34e | 485 | EMIT2_off32(0x81, add_1reg(b3, dst_reg), imm32); |
62258278 AS |
486 | break; |
487 | ||
488 | case BPF_ALU64 | BPF_MOV | BPF_K: | |
489 | /* optimization: if imm32 is positive, | |
490 | * use 'mov eax, imm32' (which zero-extends imm32) | |
491 | * to save 2 bytes | |
492 | */ | |
e430f34e | 493 | if (imm32 < 0) { |
62258278 | 494 | /* 'mov rax, imm32' sign extends imm32 */ |
e430f34e | 495 | b1 = add_1mod(0x48, dst_reg); |
62258278 AS |
496 | b2 = 0xC7; |
497 | b3 = 0xC0; | |
e430f34e | 498 | EMIT3_off32(b1, b2, add_1reg(b3, dst_reg), imm32); |
0a14842f | 499 | break; |
62258278 AS |
500 | } |
501 | ||
502 | case BPF_ALU | BPF_MOV | BPF_K: | |
606c88a8 DB |
503 | /* optimization: if imm32 is zero, use 'xor <dst>,<dst>' |
504 | * to save 3 bytes. | |
505 | */ | |
506 | if (imm32 == 0) { | |
507 | if (is_ereg(dst_reg)) | |
508 | EMIT1(add_2mod(0x40, dst_reg, dst_reg)); | |
509 | b2 = 0x31; /* xor */ | |
510 | b3 = 0xC0; | |
511 | EMIT2(b2, add_2reg(b3, dst_reg, dst_reg)); | |
512 | break; | |
513 | } | |
514 | ||
62258278 | 515 | /* mov %eax, imm32 */ |
e430f34e AS |
516 | if (is_ereg(dst_reg)) |
517 | EMIT1(add_1mod(0x40, dst_reg)); | |
518 | EMIT1_off32(add_1reg(0xB8, dst_reg), imm32); | |
62258278 AS |
519 | break; |
520 | ||
02ab695b | 521 | case BPF_LD | BPF_IMM | BPF_DW: |
606c88a8 DB |
522 | /* optimization: if imm64 is zero, use 'xor <dst>,<dst>' |
523 | * to save 7 bytes. | |
524 | */ | |
525 | if (insn[0].imm == 0 && insn[1].imm == 0) { | |
526 | b1 = add_2mod(0x48, dst_reg, dst_reg); | |
527 | b2 = 0x31; /* xor */ | |
528 | b3 = 0xC0; | |
529 | EMIT3(b1, b2, add_2reg(b3, dst_reg, dst_reg)); | |
530 | ||
531 | insn++; | |
532 | i++; | |
533 | break; | |
534 | } | |
535 | ||
02ab695b AS |
536 | /* movabsq %rax, imm64 */ |
537 | EMIT2(add_1mod(0x48, dst_reg), add_1reg(0xB8, dst_reg)); | |
538 | EMIT(insn[0].imm, 4); | |
539 | EMIT(insn[1].imm, 4); | |
540 | ||
541 | insn++; | |
542 | i++; | |
543 | break; | |
544 | ||
e430f34e | 545 | /* dst %= src, dst /= src, dst %= imm32, dst /= imm32 */ |
62258278 AS |
546 | case BPF_ALU | BPF_MOD | BPF_X: |
547 | case BPF_ALU | BPF_DIV | BPF_X: | |
548 | case BPF_ALU | BPF_MOD | BPF_K: | |
549 | case BPF_ALU | BPF_DIV | BPF_K: | |
550 | case BPF_ALU64 | BPF_MOD | BPF_X: | |
551 | case BPF_ALU64 | BPF_DIV | BPF_X: | |
552 | case BPF_ALU64 | BPF_MOD | BPF_K: | |
553 | case BPF_ALU64 | BPF_DIV | BPF_K: | |
554 | EMIT1(0x50); /* push rax */ | |
555 | EMIT1(0x52); /* push rdx */ | |
556 | ||
557 | if (BPF_SRC(insn->code) == BPF_X) | |
e430f34e AS |
558 | /* mov r11, src_reg */ |
559 | EMIT_mov(AUX_REG, src_reg); | |
62258278 | 560 | else |
e430f34e AS |
561 | /* mov r11, imm32 */ |
562 | EMIT3_off32(0x49, 0xC7, 0xC3, imm32); | |
62258278 | 563 | |
e430f34e AS |
564 | /* mov rax, dst_reg */ |
565 | EMIT_mov(BPF_REG_0, dst_reg); | |
62258278 AS |
566 | |
567 | /* xor edx, edx | |
568 | * equivalent to 'xor rdx, rdx', but one byte less | |
569 | */ | |
570 | EMIT2(0x31, 0xd2); | |
571 | ||
62258278 AS |
572 | if (BPF_CLASS(insn->code) == BPF_ALU64) |
573 | /* div r11 */ | |
574 | EMIT3(0x49, 0xF7, 0xF3); | |
575 | else | |
576 | /* div r11d */ | |
577 | EMIT3(0x41, 0xF7, 0xF3); | |
578 | ||
579 | if (BPF_OP(insn->code) == BPF_MOD) | |
580 | /* mov r11, rdx */ | |
581 | EMIT3(0x49, 0x89, 0xD3); | |
582 | else | |
583 | /* mov r11, rax */ | |
584 | EMIT3(0x49, 0x89, 0xC3); | |
585 | ||
586 | EMIT1(0x5A); /* pop rdx */ | |
587 | EMIT1(0x58); /* pop rax */ | |
588 | ||
e430f34e AS |
589 | /* mov dst_reg, r11 */ |
590 | EMIT_mov(dst_reg, AUX_REG); | |
62258278 AS |
591 | break; |
592 | ||
593 | case BPF_ALU | BPF_MUL | BPF_K: | |
594 | case BPF_ALU | BPF_MUL | BPF_X: | |
595 | case BPF_ALU64 | BPF_MUL | BPF_K: | |
596 | case BPF_ALU64 | BPF_MUL | BPF_X: | |
597 | EMIT1(0x50); /* push rax */ | |
598 | EMIT1(0x52); /* push rdx */ | |
599 | ||
e430f34e AS |
600 | /* mov r11, dst_reg */ |
601 | EMIT_mov(AUX_REG, dst_reg); | |
62258278 AS |
602 | |
603 | if (BPF_SRC(insn->code) == BPF_X) | |
e430f34e AS |
604 | /* mov rax, src_reg */ |
605 | EMIT_mov(BPF_REG_0, src_reg); | |
62258278 | 606 | else |
e430f34e AS |
607 | /* mov rax, imm32 */ |
608 | EMIT3_off32(0x48, 0xC7, 0xC0, imm32); | |
62258278 AS |
609 | |
610 | if (BPF_CLASS(insn->code) == BPF_ALU64) | |
611 | EMIT1(add_1mod(0x48, AUX_REG)); | |
612 | else if (is_ereg(AUX_REG)) | |
613 | EMIT1(add_1mod(0x40, AUX_REG)); | |
614 | /* mul(q) r11 */ | |
615 | EMIT2(0xF7, add_1reg(0xE0, AUX_REG)); | |
616 | ||
617 | /* mov r11, rax */ | |
618 | EMIT_mov(AUX_REG, BPF_REG_0); | |
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 | /* shifts */ | |
628 | case BPF_ALU | BPF_LSH | BPF_K: | |
629 | case BPF_ALU | BPF_RSH | BPF_K: | |
630 | case BPF_ALU | BPF_ARSH | BPF_K: | |
631 | case BPF_ALU64 | BPF_LSH | BPF_K: | |
632 | case BPF_ALU64 | BPF_RSH | BPF_K: | |
633 | case BPF_ALU64 | BPF_ARSH | BPF_K: | |
634 | if (BPF_CLASS(insn->code) == BPF_ALU64) | |
e430f34e AS |
635 | EMIT1(add_1mod(0x48, dst_reg)); |
636 | else if (is_ereg(dst_reg)) | |
637 | EMIT1(add_1mod(0x40, dst_reg)); | |
62258278 AS |
638 | |
639 | switch (BPF_OP(insn->code)) { | |
640 | case BPF_LSH: b3 = 0xE0; break; | |
641 | case BPF_RSH: b3 = 0xE8; break; | |
642 | case BPF_ARSH: b3 = 0xF8; break; | |
643 | } | |
e430f34e | 644 | EMIT3(0xC1, add_1reg(b3, dst_reg), imm32); |
62258278 AS |
645 | break; |
646 | ||
72b603ee AS |
647 | case BPF_ALU | BPF_LSH | BPF_X: |
648 | case BPF_ALU | BPF_RSH | BPF_X: | |
649 | case BPF_ALU | BPF_ARSH | BPF_X: | |
650 | case BPF_ALU64 | BPF_LSH | BPF_X: | |
651 | case BPF_ALU64 | BPF_RSH | BPF_X: | |
652 | case BPF_ALU64 | BPF_ARSH | BPF_X: | |
653 | ||
654 | /* check for bad case when dst_reg == rcx */ | |
655 | if (dst_reg == BPF_REG_4) { | |
656 | /* mov r11, dst_reg */ | |
657 | EMIT_mov(AUX_REG, dst_reg); | |
658 | dst_reg = AUX_REG; | |
659 | } | |
660 | ||
661 | if (src_reg != BPF_REG_4) { /* common case */ | |
662 | EMIT1(0x51); /* push rcx */ | |
663 | ||
664 | /* mov rcx, src_reg */ | |
665 | EMIT_mov(BPF_REG_4, src_reg); | |
666 | } | |
667 | ||
668 | /* shl %rax, %cl | shr %rax, %cl | sar %rax, %cl */ | |
669 | if (BPF_CLASS(insn->code) == BPF_ALU64) | |
670 | EMIT1(add_1mod(0x48, dst_reg)); | |
671 | else if (is_ereg(dst_reg)) | |
672 | EMIT1(add_1mod(0x40, dst_reg)); | |
673 | ||
674 | switch (BPF_OP(insn->code)) { | |
675 | case BPF_LSH: b3 = 0xE0; break; | |
676 | case BPF_RSH: b3 = 0xE8; break; | |
677 | case BPF_ARSH: b3 = 0xF8; break; | |
678 | } | |
679 | EMIT2(0xD3, add_1reg(b3, dst_reg)); | |
680 | ||
681 | if (src_reg != BPF_REG_4) | |
682 | EMIT1(0x59); /* pop rcx */ | |
683 | ||
684 | if (insn->dst_reg == BPF_REG_4) | |
685 | /* mov dst_reg, r11 */ | |
686 | EMIT_mov(insn->dst_reg, AUX_REG); | |
687 | break; | |
688 | ||
62258278 | 689 | case BPF_ALU | BPF_END | BPF_FROM_BE: |
e430f34e | 690 | switch (imm32) { |
62258278 AS |
691 | case 16: |
692 | /* emit 'ror %ax, 8' to swap lower 2 bytes */ | |
693 | EMIT1(0x66); | |
e430f34e | 694 | if (is_ereg(dst_reg)) |
62258278 | 695 | EMIT1(0x41); |
e430f34e | 696 | EMIT3(0xC1, add_1reg(0xC8, dst_reg), 8); |
343f845b AS |
697 | |
698 | /* emit 'movzwl eax, ax' */ | |
699 | if (is_ereg(dst_reg)) | |
700 | EMIT3(0x45, 0x0F, 0xB7); | |
701 | else | |
702 | EMIT2(0x0F, 0xB7); | |
703 | EMIT1(add_2reg(0xC0, dst_reg, dst_reg)); | |
62258278 AS |
704 | break; |
705 | case 32: | |
706 | /* emit 'bswap eax' to swap lower 4 bytes */ | |
e430f34e | 707 | if (is_ereg(dst_reg)) |
62258278 | 708 | EMIT2(0x41, 0x0F); |
0a14842f | 709 | else |
62258278 | 710 | EMIT1(0x0F); |
e430f34e | 711 | EMIT1(add_1reg(0xC8, dst_reg)); |
0a14842f | 712 | break; |
62258278 AS |
713 | case 64: |
714 | /* emit 'bswap rax' to swap 8 bytes */ | |
e430f34e AS |
715 | EMIT3(add_1mod(0x48, dst_reg), 0x0F, |
716 | add_1reg(0xC8, dst_reg)); | |
3b58908a ED |
717 | break; |
718 | } | |
62258278 AS |
719 | break; |
720 | ||
721 | case BPF_ALU | BPF_END | BPF_FROM_LE: | |
343f845b AS |
722 | switch (imm32) { |
723 | case 16: | |
724 | /* emit 'movzwl eax, ax' to zero extend 16-bit | |
725 | * into 64 bit | |
726 | */ | |
727 | if (is_ereg(dst_reg)) | |
728 | EMIT3(0x45, 0x0F, 0xB7); | |
729 | else | |
730 | EMIT2(0x0F, 0xB7); | |
731 | EMIT1(add_2reg(0xC0, dst_reg, dst_reg)); | |
732 | break; | |
733 | case 32: | |
734 | /* emit 'mov eax, eax' to clear upper 32-bits */ | |
735 | if (is_ereg(dst_reg)) | |
736 | EMIT1(0x45); | |
737 | EMIT2(0x89, add_2reg(0xC0, dst_reg, dst_reg)); | |
738 | break; | |
739 | case 64: | |
740 | /* nop */ | |
741 | break; | |
742 | } | |
62258278 AS |
743 | break; |
744 | ||
e430f34e | 745 | /* ST: *(u8*)(dst_reg + off) = imm */ |
62258278 | 746 | case BPF_ST | BPF_MEM | BPF_B: |
e430f34e | 747 | if (is_ereg(dst_reg)) |
62258278 AS |
748 | EMIT2(0x41, 0xC6); |
749 | else | |
750 | EMIT1(0xC6); | |
751 | goto st; | |
752 | case BPF_ST | BPF_MEM | BPF_H: | |
e430f34e | 753 | if (is_ereg(dst_reg)) |
62258278 AS |
754 | EMIT3(0x66, 0x41, 0xC7); |
755 | else | |
756 | EMIT2(0x66, 0xC7); | |
757 | goto st; | |
758 | case BPF_ST | BPF_MEM | BPF_W: | |
e430f34e | 759 | if (is_ereg(dst_reg)) |
62258278 AS |
760 | EMIT2(0x41, 0xC7); |
761 | else | |
762 | EMIT1(0xC7); | |
763 | goto st; | |
764 | case BPF_ST | BPF_MEM | BPF_DW: | |
e430f34e | 765 | EMIT2(add_1mod(0x48, dst_reg), 0xC7); |
62258278 AS |
766 | |
767 | st: if (is_imm8(insn->off)) | |
e430f34e | 768 | EMIT2(add_1reg(0x40, dst_reg), insn->off); |
62258278 | 769 | else |
e430f34e | 770 | EMIT1_off32(add_1reg(0x80, dst_reg), insn->off); |
62258278 | 771 | |
e430f34e | 772 | EMIT(imm32, bpf_size_to_x86_bytes(BPF_SIZE(insn->code))); |
62258278 AS |
773 | break; |
774 | ||
e430f34e | 775 | /* STX: *(u8*)(dst_reg + off) = src_reg */ |
62258278 AS |
776 | case BPF_STX | BPF_MEM | BPF_B: |
777 | /* emit 'mov byte ptr [rax + off], al' */ | |
e430f34e | 778 | if (is_ereg(dst_reg) || is_ereg(src_reg) || |
62258278 | 779 | /* have to add extra byte for x86 SIL, DIL regs */ |
e430f34e AS |
780 | src_reg == BPF_REG_1 || src_reg == BPF_REG_2) |
781 | EMIT2(add_2mod(0x40, dst_reg, src_reg), 0x88); | |
62258278 AS |
782 | else |
783 | EMIT1(0x88); | |
784 | goto stx; | |
785 | case BPF_STX | BPF_MEM | BPF_H: | |
e430f34e AS |
786 | if (is_ereg(dst_reg) || is_ereg(src_reg)) |
787 | EMIT3(0x66, add_2mod(0x40, dst_reg, src_reg), 0x89); | |
62258278 AS |
788 | else |
789 | EMIT2(0x66, 0x89); | |
790 | goto stx; | |
791 | case BPF_STX | BPF_MEM | BPF_W: | |
e430f34e AS |
792 | if (is_ereg(dst_reg) || is_ereg(src_reg)) |
793 | EMIT2(add_2mod(0x40, dst_reg, src_reg), 0x89); | |
62258278 AS |
794 | else |
795 | EMIT1(0x89); | |
796 | goto stx; | |
797 | case BPF_STX | BPF_MEM | BPF_DW: | |
e430f34e | 798 | EMIT2(add_2mod(0x48, dst_reg, src_reg), 0x89); |
62258278 | 799 | stx: if (is_imm8(insn->off)) |
e430f34e | 800 | EMIT2(add_2reg(0x40, dst_reg, src_reg), insn->off); |
62258278 | 801 | else |
e430f34e | 802 | EMIT1_off32(add_2reg(0x80, dst_reg, src_reg), |
62258278 AS |
803 | insn->off); |
804 | break; | |
805 | ||
e430f34e | 806 | /* LDX: dst_reg = *(u8*)(src_reg + off) */ |
62258278 AS |
807 | case BPF_LDX | BPF_MEM | BPF_B: |
808 | /* emit 'movzx rax, byte ptr [rax + off]' */ | |
e430f34e | 809 | EMIT3(add_2mod(0x48, src_reg, dst_reg), 0x0F, 0xB6); |
62258278 AS |
810 | goto ldx; |
811 | case BPF_LDX | BPF_MEM | BPF_H: | |
812 | /* emit 'movzx rax, word ptr [rax + off]' */ | |
e430f34e | 813 | EMIT3(add_2mod(0x48, src_reg, dst_reg), 0x0F, 0xB7); |
62258278 AS |
814 | goto ldx; |
815 | case BPF_LDX | BPF_MEM | BPF_W: | |
816 | /* emit 'mov eax, dword ptr [rax+0x14]' */ | |
e430f34e AS |
817 | if (is_ereg(dst_reg) || is_ereg(src_reg)) |
818 | EMIT2(add_2mod(0x40, src_reg, dst_reg), 0x8B); | |
62258278 AS |
819 | else |
820 | EMIT1(0x8B); | |
821 | goto ldx; | |
822 | case BPF_LDX | BPF_MEM | BPF_DW: | |
823 | /* emit 'mov rax, qword ptr [rax+0x14]' */ | |
e430f34e | 824 | EMIT2(add_2mod(0x48, src_reg, dst_reg), 0x8B); |
62258278 AS |
825 | ldx: /* if insn->off == 0 we can save one extra byte, but |
826 | * special case of x86 r13 which always needs an offset | |
827 | * is not worth the hassle | |
828 | */ | |
829 | if (is_imm8(insn->off)) | |
e430f34e | 830 | EMIT2(add_2reg(0x40, src_reg, dst_reg), insn->off); |
62258278 | 831 | else |
e430f34e | 832 | EMIT1_off32(add_2reg(0x80, src_reg, dst_reg), |
62258278 AS |
833 | insn->off); |
834 | break; | |
835 | ||
e430f34e | 836 | /* STX XADD: lock *(u32*)(dst_reg + off) += src_reg */ |
62258278 AS |
837 | case BPF_STX | BPF_XADD | BPF_W: |
838 | /* emit 'lock add dword ptr [rax + off], eax' */ | |
e430f34e AS |
839 | if (is_ereg(dst_reg) || is_ereg(src_reg)) |
840 | EMIT3(0xF0, add_2mod(0x40, dst_reg, src_reg), 0x01); | |
62258278 AS |
841 | else |
842 | EMIT2(0xF0, 0x01); | |
843 | goto xadd; | |
844 | case BPF_STX | BPF_XADD | BPF_DW: | |
e430f34e | 845 | EMIT3(0xF0, add_2mod(0x48, dst_reg, src_reg), 0x01); |
62258278 | 846 | xadd: if (is_imm8(insn->off)) |
e430f34e | 847 | EMIT2(add_2reg(0x40, dst_reg, src_reg), insn->off); |
62258278 | 848 | else |
e430f34e | 849 | EMIT1_off32(add_2reg(0x80, dst_reg, src_reg), |
62258278 AS |
850 | insn->off); |
851 | break; | |
852 | ||
853 | /* call */ | |
854 | case BPF_JMP | BPF_CALL: | |
e430f34e | 855 | func = (u8 *) __bpf_call_base + imm32; |
62258278 | 856 | jmp_offset = func - (image + addrs[i]); |
e0ee9c12 | 857 | if (seen_ld_abs) { |
17bedab2 | 858 | reload_skb_data = bpf_helper_changes_pkt_data(func); |
4e10df9a AS |
859 | if (reload_skb_data) { |
860 | EMIT1(0x57); /* push %rdi */ | |
861 | jmp_offset += 22; /* pop, mov, sub, mov */ | |
862 | } else { | |
863 | EMIT2(0x41, 0x52); /* push %r10 */ | |
864 | EMIT2(0x41, 0x51); /* push %r9 */ | |
865 | /* need to adjust jmp offset, since | |
866 | * pop %r9, pop %r10 take 4 bytes after call insn | |
867 | */ | |
868 | jmp_offset += 4; | |
869 | } | |
62258278 | 870 | } |
e430f34e | 871 | if (!imm32 || !is_simm32(jmp_offset)) { |
62258278 | 872 | pr_err("unsupported bpf func %d addr %p image %p\n", |
e430f34e | 873 | imm32, func, image); |
62258278 AS |
874 | return -EINVAL; |
875 | } | |
876 | EMIT1_off32(0xE8, jmp_offset); | |
e0ee9c12 | 877 | if (seen_ld_abs) { |
4e10df9a AS |
878 | if (reload_skb_data) { |
879 | EMIT1(0x5F); /* pop %rdi */ | |
880 | emit_load_skb_data_hlen(&prog); | |
881 | } else { | |
882 | EMIT2(0x41, 0x59); /* pop %r9 */ | |
883 | EMIT2(0x41, 0x5A); /* pop %r10 */ | |
884 | } | |
62258278 AS |
885 | } |
886 | break; | |
887 | ||
71189fa9 | 888 | case BPF_JMP | BPF_TAIL_CALL: |
b52f00e6 AS |
889 | emit_bpf_tail_call(&prog); |
890 | break; | |
891 | ||
62258278 AS |
892 | /* cond jump */ |
893 | case BPF_JMP | BPF_JEQ | BPF_X: | |
894 | case BPF_JMP | BPF_JNE | BPF_X: | |
895 | case BPF_JMP | BPF_JGT | BPF_X: | |
52afc51e | 896 | case BPF_JMP | BPF_JLT | BPF_X: |
62258278 | 897 | case BPF_JMP | BPF_JGE | BPF_X: |
52afc51e | 898 | case BPF_JMP | BPF_JLE | BPF_X: |
62258278 | 899 | case BPF_JMP | BPF_JSGT | BPF_X: |
52afc51e | 900 | case BPF_JMP | BPF_JSLT | BPF_X: |
62258278 | 901 | case BPF_JMP | BPF_JSGE | BPF_X: |
52afc51e | 902 | case BPF_JMP | BPF_JSLE | BPF_X: |
e430f34e AS |
903 | /* cmp dst_reg, src_reg */ |
904 | EMIT3(add_2mod(0x48, dst_reg, src_reg), 0x39, | |
905 | add_2reg(0xC0, dst_reg, src_reg)); | |
62258278 AS |
906 | goto emit_cond_jmp; |
907 | ||
908 | case BPF_JMP | BPF_JSET | BPF_X: | |
e430f34e AS |
909 | /* test dst_reg, src_reg */ |
910 | EMIT3(add_2mod(0x48, dst_reg, src_reg), 0x85, | |
911 | add_2reg(0xC0, dst_reg, src_reg)); | |
62258278 AS |
912 | goto emit_cond_jmp; |
913 | ||
914 | case BPF_JMP | BPF_JSET | BPF_K: | |
e430f34e AS |
915 | /* test dst_reg, imm32 */ |
916 | EMIT1(add_1mod(0x48, dst_reg)); | |
917 | EMIT2_off32(0xF7, add_1reg(0xC0, dst_reg), imm32); | |
62258278 AS |
918 | goto emit_cond_jmp; |
919 | ||
920 | case BPF_JMP | BPF_JEQ | BPF_K: | |
921 | case BPF_JMP | BPF_JNE | BPF_K: | |
922 | case BPF_JMP | BPF_JGT | BPF_K: | |
52afc51e | 923 | case BPF_JMP | BPF_JLT | BPF_K: |
62258278 | 924 | case BPF_JMP | BPF_JGE | BPF_K: |
52afc51e | 925 | case BPF_JMP | BPF_JLE | BPF_K: |
62258278 | 926 | case BPF_JMP | BPF_JSGT | BPF_K: |
52afc51e | 927 | case BPF_JMP | BPF_JSLT | BPF_K: |
62258278 | 928 | case BPF_JMP | BPF_JSGE | BPF_K: |
52afc51e | 929 | case BPF_JMP | BPF_JSLE | BPF_K: |
e430f34e AS |
930 | /* cmp dst_reg, imm8/32 */ |
931 | EMIT1(add_1mod(0x48, dst_reg)); | |
62258278 | 932 | |
e430f34e AS |
933 | if (is_imm8(imm32)) |
934 | EMIT3(0x83, add_1reg(0xF8, dst_reg), imm32); | |
62258278 | 935 | else |
e430f34e | 936 | EMIT2_off32(0x81, add_1reg(0xF8, dst_reg), imm32); |
62258278 AS |
937 | |
938 | emit_cond_jmp: /* convert BPF opcode to x86 */ | |
939 | switch (BPF_OP(insn->code)) { | |
940 | case BPF_JEQ: | |
941 | jmp_cond = X86_JE; | |
942 | break; | |
943 | case BPF_JSET: | |
944 | case BPF_JNE: | |
945 | jmp_cond = X86_JNE; | |
946 | break; | |
947 | case BPF_JGT: | |
948 | /* GT is unsigned '>', JA in x86 */ | |
949 | jmp_cond = X86_JA; | |
950 | break; | |
52afc51e DB |
951 | case BPF_JLT: |
952 | /* LT is unsigned '<', JB in x86 */ | |
953 | jmp_cond = X86_JB; | |
954 | break; | |
62258278 AS |
955 | case BPF_JGE: |
956 | /* GE is unsigned '>=', JAE in x86 */ | |
957 | jmp_cond = X86_JAE; | |
958 | break; | |
52afc51e DB |
959 | case BPF_JLE: |
960 | /* LE is unsigned '<=', JBE in x86 */ | |
961 | jmp_cond = X86_JBE; | |
962 | break; | |
62258278 AS |
963 | case BPF_JSGT: |
964 | /* signed '>', GT in x86 */ | |
965 | jmp_cond = X86_JG; | |
966 | break; | |
52afc51e DB |
967 | case BPF_JSLT: |
968 | /* signed '<', LT in x86 */ | |
969 | jmp_cond = X86_JL; | |
970 | break; | |
62258278 AS |
971 | case BPF_JSGE: |
972 | /* signed '>=', GE in x86 */ | |
973 | jmp_cond = X86_JGE; | |
974 | break; | |
52afc51e DB |
975 | case BPF_JSLE: |
976 | /* signed '<=', LE in x86 */ | |
977 | jmp_cond = X86_JLE; | |
978 | break; | |
62258278 AS |
979 | default: /* to silence gcc warning */ |
980 | return -EFAULT; | |
981 | } | |
982 | jmp_offset = addrs[i + insn->off] - addrs[i]; | |
983 | if (is_imm8(jmp_offset)) { | |
984 | EMIT2(jmp_cond, jmp_offset); | |
985 | } else if (is_simm32(jmp_offset)) { | |
986 | EMIT2_off32(0x0F, jmp_cond + 0x10, jmp_offset); | |
987 | } else { | |
988 | pr_err("cond_jmp gen bug %llx\n", jmp_offset); | |
989 | return -EFAULT; | |
990 | } | |
991 | ||
992 | break; | |
0a14842f | 993 | |
62258278 AS |
994 | case BPF_JMP | BPF_JA: |
995 | jmp_offset = addrs[i + insn->off] - addrs[i]; | |
996 | if (!jmp_offset) | |
997 | /* optimize out nop jumps */ | |
998 | break; | |
999 | emit_jmp: | |
1000 | if (is_imm8(jmp_offset)) { | |
1001 | EMIT2(0xEB, jmp_offset); | |
1002 | } else if (is_simm32(jmp_offset)) { | |
1003 | EMIT1_off32(0xE9, jmp_offset); | |
1004 | } else { | |
1005 | pr_err("jmp gen bug %llx\n", jmp_offset); | |
1006 | return -EFAULT; | |
1007 | } | |
1008 | break; | |
1009 | ||
1010 | case BPF_LD | BPF_IND | BPF_W: | |
1011 | func = sk_load_word; | |
1012 | goto common_load; | |
1013 | case BPF_LD | BPF_ABS | BPF_W: | |
e430f34e | 1014 | func = CHOOSE_LOAD_FUNC(imm32, sk_load_word); |
e0ee9c12 AS |
1015 | common_load: |
1016 | ctx->seen_ld_abs = seen_ld_abs = true; | |
62258278 AS |
1017 | jmp_offset = func - (image + addrs[i]); |
1018 | if (!func || !is_simm32(jmp_offset)) { | |
1019 | pr_err("unsupported bpf func %d addr %p image %p\n", | |
e430f34e | 1020 | imm32, func, image); |
62258278 AS |
1021 | return -EINVAL; |
1022 | } | |
1023 | if (BPF_MODE(insn->code) == BPF_ABS) { | |
1024 | /* mov %esi, imm32 */ | |
e430f34e | 1025 | EMIT1_off32(0xBE, imm32); |
62258278 | 1026 | } else { |
e430f34e AS |
1027 | /* mov %rsi, src_reg */ |
1028 | EMIT_mov(BPF_REG_2, src_reg); | |
1029 | if (imm32) { | |
1030 | if (is_imm8(imm32)) | |
62258278 | 1031 | /* add %esi, imm8 */ |
e430f34e | 1032 | EMIT3(0x83, 0xC6, imm32); |
0a14842f | 1033 | else |
62258278 | 1034 | /* add %esi, imm32 */ |
e430f34e | 1035 | EMIT2_off32(0x81, 0xC6, imm32); |
0a14842f | 1036 | } |
62258278 AS |
1037 | } |
1038 | /* skb pointer is in R6 (%rbx), it will be copied into | |
1039 | * %rdi if skb_copy_bits() call is necessary. | |
1040 | * sk_load_* helpers also use %r10 and %r9d. | |
1041 | * See bpf_jit.S | |
1042 | */ | |
959a7579 DB |
1043 | if (seen_ax_reg) |
1044 | /* r10 = skb->data, mov %r10, off32(%rbx) */ | |
1045 | EMIT3_off32(0x4c, 0x8b, 0x93, | |
1046 | offsetof(struct sk_buff, data)); | |
62258278 AS |
1047 | EMIT1_off32(0xE8, jmp_offset); /* call */ |
1048 | break; | |
1049 | ||
1050 | case BPF_LD | BPF_IND | BPF_H: | |
1051 | func = sk_load_half; | |
1052 | goto common_load; | |
1053 | case BPF_LD | BPF_ABS | BPF_H: | |
e430f34e | 1054 | func = CHOOSE_LOAD_FUNC(imm32, sk_load_half); |
62258278 AS |
1055 | goto common_load; |
1056 | case BPF_LD | BPF_IND | BPF_B: | |
1057 | func = sk_load_byte; | |
1058 | goto common_load; | |
1059 | case BPF_LD | BPF_ABS | BPF_B: | |
e430f34e | 1060 | func = CHOOSE_LOAD_FUNC(imm32, sk_load_byte); |
62258278 AS |
1061 | goto common_load; |
1062 | ||
1063 | case BPF_JMP | BPF_EXIT: | |
769e0de6 | 1064 | if (seen_exit) { |
62258278 AS |
1065 | jmp_offset = ctx->cleanup_addr - addrs[i]; |
1066 | goto emit_jmp; | |
1067 | } | |
769e0de6 | 1068 | seen_exit = true; |
62258278 AS |
1069 | /* update cleanup_addr */ |
1070 | ctx->cleanup_addr = proglen; | |
177366bf AS |
1071 | /* mov rbx, qword ptr [rbp+0] */ |
1072 | EMIT4(0x48, 0x8B, 0x5D, 0); | |
1073 | /* mov r13, qword ptr [rbp+8] */ | |
1074 | EMIT4(0x4C, 0x8B, 0x6D, 8); | |
1075 | /* mov r14, qword ptr [rbp+16] */ | |
1076 | EMIT4(0x4C, 0x8B, 0x75, 16); | |
1077 | /* mov r15, qword ptr [rbp+24] */ | |
1078 | EMIT4(0x4C, 0x8B, 0x7D, 24); | |
1079 | ||
1080 | /* add rbp, AUX_STACK_SPACE */ | |
1081 | EMIT4(0x48, 0x83, 0xC5, AUX_STACK_SPACE); | |
62258278 AS |
1082 | EMIT1(0xC9); /* leave */ |
1083 | EMIT1(0xC3); /* ret */ | |
1084 | break; | |
1085 | ||
f3c2af7b | 1086 | default: |
62258278 AS |
1087 | /* By design x64 JIT should support all BPF instructions |
1088 | * This error will be seen if new instruction was added | |
1089 | * to interpreter, but not to JIT | |
7ae457c1 | 1090 | * or if there is junk in bpf_prog |
62258278 AS |
1091 | */ |
1092 | pr_err("bpf_jit: unknown opcode %02x\n", insn->code); | |
f3c2af7b AS |
1093 | return -EINVAL; |
1094 | } | |
62258278 | 1095 | |
f3c2af7b | 1096 | ilen = prog - temp; |
e0ee9c12 | 1097 | if (ilen > BPF_MAX_INSN_SIZE) { |
9383191d | 1098 | pr_err("bpf_jit: fatal insn size error\n"); |
e0ee9c12 AS |
1099 | return -EFAULT; |
1100 | } | |
1101 | ||
f3c2af7b AS |
1102 | if (image) { |
1103 | if (unlikely(proglen + ilen > oldproglen)) { | |
9383191d | 1104 | pr_err("bpf_jit: fatal error\n"); |
f3c2af7b | 1105 | return -EFAULT; |
0a14842f | 1106 | } |
f3c2af7b | 1107 | memcpy(image + proglen, temp, ilen); |
0a14842f | 1108 | } |
f3c2af7b AS |
1109 | proglen += ilen; |
1110 | addrs[i] = proglen; | |
1111 | prog = temp; | |
1112 | } | |
f3c2af7b AS |
1113 | return proglen; |
1114 | } | |
1115 | ||
1c2a088a AS |
1116 | struct x64_jit_data { |
1117 | struct bpf_binary_header *header; | |
1118 | int *addrs; | |
1119 | u8 *image; | |
1120 | int proglen; | |
1121 | struct jit_context ctx; | |
1122 | }; | |
1123 | ||
d1c55ab5 | 1124 | struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog) |
f3c2af7b AS |
1125 | { |
1126 | struct bpf_binary_header *header = NULL; | |
959a7579 | 1127 | struct bpf_prog *tmp, *orig_prog = prog; |
1c2a088a | 1128 | struct x64_jit_data *jit_data; |
f3c2af7b AS |
1129 | int proglen, oldproglen = 0; |
1130 | struct jit_context ctx = {}; | |
959a7579 | 1131 | bool tmp_blinded = false; |
1c2a088a | 1132 | bool extra_pass = false; |
f3c2af7b AS |
1133 | u8 *image = NULL; |
1134 | int *addrs; | |
1135 | int pass; | |
1136 | int i; | |
1137 | ||
60b58afc | 1138 | if (!prog->jit_requested) |
959a7579 DB |
1139 | return orig_prog; |
1140 | ||
1141 | tmp = bpf_jit_blind_constants(prog); | |
1142 | /* If blinding was requested and we failed during blinding, | |
1143 | * we must fall back to the interpreter. | |
1144 | */ | |
1145 | if (IS_ERR(tmp)) | |
1146 | return orig_prog; | |
1147 | if (tmp != prog) { | |
1148 | tmp_blinded = true; | |
1149 | prog = tmp; | |
1150 | } | |
0a14842f | 1151 | |
1c2a088a AS |
1152 | jit_data = prog->aux->jit_data; |
1153 | if (!jit_data) { | |
1154 | jit_data = kzalloc(sizeof(*jit_data), GFP_KERNEL); | |
1155 | if (!jit_data) { | |
1156 | prog = orig_prog; | |
1157 | goto out; | |
1158 | } | |
1159 | prog->aux->jit_data = jit_data; | |
1160 | } | |
1161 | addrs = jit_data->addrs; | |
1162 | if (addrs) { | |
1163 | ctx = jit_data->ctx; | |
1164 | oldproglen = jit_data->proglen; | |
1165 | image = jit_data->image; | |
1166 | header = jit_data->header; | |
1167 | extra_pass = true; | |
1168 | goto skip_init_addrs; | |
1169 | } | |
f3c2af7b | 1170 | addrs = kmalloc(prog->len * sizeof(*addrs), GFP_KERNEL); |
959a7579 DB |
1171 | if (!addrs) { |
1172 | prog = orig_prog; | |
1c2a088a | 1173 | goto out_addrs; |
959a7579 | 1174 | } |
f3c2af7b AS |
1175 | |
1176 | /* Before first pass, make a rough estimation of addrs[] | |
1177 | * each bpf instruction is translated to less than 64 bytes | |
1178 | */ | |
1179 | for (proglen = 0, i = 0; i < prog->len; i++) { | |
1180 | proglen += 64; | |
1181 | addrs[i] = proglen; | |
1182 | } | |
1183 | ctx.cleanup_addr = proglen; | |
1c2a088a | 1184 | skip_init_addrs: |
f3c2af7b | 1185 | |
3f7352bf AS |
1186 | /* JITed image shrinks with every pass and the loop iterates |
1187 | * until the image stops shrinking. Very large bpf programs | |
1188 | * may converge on the last pass. In such case do one more | |
1189 | * pass to emit the final image | |
1190 | */ | |
6007b080 | 1191 | for (pass = 0; pass < 20 || image; pass++) { |
f3c2af7b AS |
1192 | proglen = do_jit(prog, addrs, image, oldproglen, &ctx); |
1193 | if (proglen <= 0) { | |
1194 | image = NULL; | |
1195 | if (header) | |
738cbe72 | 1196 | bpf_jit_binary_free(header); |
959a7579 DB |
1197 | prog = orig_prog; |
1198 | goto out_addrs; | |
f3c2af7b | 1199 | } |
0a14842f | 1200 | if (image) { |
e0ee9c12 | 1201 | if (proglen != oldproglen) { |
f3c2af7b AS |
1202 | pr_err("bpf_jit: proglen=%d != oldproglen=%d\n", |
1203 | proglen, oldproglen); | |
959a7579 DB |
1204 | prog = orig_prog; |
1205 | goto out_addrs; | |
e0ee9c12 | 1206 | } |
0a14842f ED |
1207 | break; |
1208 | } | |
1209 | if (proglen == oldproglen) { | |
738cbe72 DB |
1210 | header = bpf_jit_binary_alloc(proglen, &image, |
1211 | 1, jit_fill_hole); | |
959a7579 DB |
1212 | if (!header) { |
1213 | prog = orig_prog; | |
1214 | goto out_addrs; | |
1215 | } | |
0a14842f ED |
1216 | } |
1217 | oldproglen = proglen; | |
6007b080 | 1218 | cond_resched(); |
0a14842f | 1219 | } |
79617801 | 1220 | |
0a14842f | 1221 | if (bpf_jit_enable > 1) |
485d6511 | 1222 | bpf_jit_dump(prog->len, proglen, pass + 1, image); |
0a14842f ED |
1223 | |
1224 | if (image) { | |
314beb9b | 1225 | bpf_flush_icache(header, image + proglen); |
1c2a088a AS |
1226 | if (!prog->is_func || extra_pass) { |
1227 | bpf_jit_binary_lock_ro(header); | |
1228 | } else { | |
1229 | jit_data->addrs = addrs; | |
1230 | jit_data->ctx = ctx; | |
1231 | jit_data->proglen = proglen; | |
1232 | jit_data->image = image; | |
1233 | jit_data->header = header; | |
1234 | } | |
f3c2af7b | 1235 | prog->bpf_func = (void *)image; |
a91263d5 | 1236 | prog->jited = 1; |
783d28dd | 1237 | prog->jited_len = proglen; |
9d5ecb09 DB |
1238 | } else { |
1239 | prog = orig_prog; | |
0a14842f | 1240 | } |
959a7579 | 1241 | |
1c2a088a | 1242 | if (!prog->is_func || extra_pass) { |
959a7579 | 1243 | out_addrs: |
1c2a088a AS |
1244 | kfree(addrs); |
1245 | kfree(jit_data); | |
1246 | prog->aux->jit_data = NULL; | |
1247 | } | |
959a7579 DB |
1248 | out: |
1249 | if (tmp_blinded) | |
1250 | bpf_jit_prog_release_other(prog, prog == orig_prog ? | |
1251 | tmp : orig_prog); | |
d1c55ab5 | 1252 | return prog; |
0a14842f | 1253 | } |