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b886d83c | 1 | // SPDX-License-Identifier: GPL-2.0-only |
a2c7a983 IM |
2 | /* |
3 | * bpf_jit_comp.c: BPF JIT compiler | |
0a14842f | 4 | * |
3b58908a | 5 | * Copyright (C) 2011-2013 Eric Dumazet (eric.dumazet@gmail.com) |
62258278 | 6 | * Internal BPF Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com |
0a14842f | 7 | */ |
0a14842f ED |
8 | #include <linux/netdevice.h> |
9 | #include <linux/filter.h> | |
855ddb56 | 10 | #include <linux/if_vlan.h> |
71d22d58 | 11 | #include <linux/bpf.h> |
5964b200 | 12 | #include <linux/memory.h> |
75ccbef6 | 13 | #include <linux/sort.h> |
3dec541b | 14 | #include <asm/extable.h> |
d1163651 | 15 | #include <asm/set_memory.h> |
a493a87f | 16 | #include <asm/nospec-branch.h> |
5964b200 | 17 | #include <asm/text-patching.h> |
75ccbef6 | 18 | #include <asm/asm-prototypes.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) |
fec56f58 | 103 | #define X86_REG_R9 (MAX_BPF_JIT_REG + 2) |
62258278 | 104 | |
a2c7a983 IM |
105 | /* |
106 | * The following table maps BPF registers to x86-64 registers. | |
959a7579 | 107 | * |
a2c7a983 | 108 | * x86-64 register R12 is unused, since if used as base address |
959a7579 DB |
109 | * register in load/store instructions, it always needs an |
110 | * extra byte of encoding and is callee saved. | |
111 | * | |
fec56f58 AS |
112 | * x86-64 register R9 is not used by BPF programs, but can be used by BPF |
113 | * trampoline. x86-64 register R10 is used for blinding (if enabled). | |
62258278 AS |
114 | */ |
115 | static const int reg2hex[] = { | |
a2c7a983 IM |
116 | [BPF_REG_0] = 0, /* RAX */ |
117 | [BPF_REG_1] = 7, /* RDI */ | |
118 | [BPF_REG_2] = 6, /* RSI */ | |
119 | [BPF_REG_3] = 2, /* RDX */ | |
120 | [BPF_REG_4] = 1, /* RCX */ | |
121 | [BPF_REG_5] = 0, /* R8 */ | |
122 | [BPF_REG_6] = 3, /* RBX callee saved */ | |
123 | [BPF_REG_7] = 5, /* R13 callee saved */ | |
124 | [BPF_REG_8] = 6, /* R14 callee saved */ | |
125 | [BPF_REG_9] = 7, /* R15 callee saved */ | |
126 | [BPF_REG_FP] = 5, /* RBP readonly */ | |
127 | [BPF_REG_AX] = 2, /* R10 temp register */ | |
128 | [AUX_REG] = 3, /* R11 temp register */ | |
fec56f58 | 129 | [X86_REG_R9] = 1, /* R9 register, 6th function argument */ |
62258278 AS |
130 | }; |
131 | ||
3dec541b AS |
132 | static const int reg2pt_regs[] = { |
133 | [BPF_REG_0] = offsetof(struct pt_regs, ax), | |
134 | [BPF_REG_1] = offsetof(struct pt_regs, di), | |
135 | [BPF_REG_2] = offsetof(struct pt_regs, si), | |
136 | [BPF_REG_3] = offsetof(struct pt_regs, dx), | |
137 | [BPF_REG_4] = offsetof(struct pt_regs, cx), | |
138 | [BPF_REG_5] = offsetof(struct pt_regs, r8), | |
139 | [BPF_REG_6] = offsetof(struct pt_regs, bx), | |
140 | [BPF_REG_7] = offsetof(struct pt_regs, r13), | |
141 | [BPF_REG_8] = offsetof(struct pt_regs, r14), | |
142 | [BPF_REG_9] = offsetof(struct pt_regs, r15), | |
143 | }; | |
144 | ||
a2c7a983 IM |
145 | /* |
146 | * is_ereg() == true if BPF register 'reg' maps to x86-64 r8..r15 | |
62258278 AS |
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 | 156 | BIT(BPF_REG_9) | |
fec56f58 | 157 | BIT(X86_REG_R9) | |
959a7579 | 158 | BIT(BPF_REG_AX)); |
62258278 AS |
159 | } |
160 | ||
aee194b1 LN |
161 | /* |
162 | * is_ereg_8l() == true if BPF register 'reg' is mapped to access x86-64 | |
163 | * lower 8-bit registers dil,sil,bpl,spl,r8b..r15b, which need extra byte | |
164 | * of encoding. al,cl,dl,bl have simpler encoding. | |
165 | */ | |
166 | static bool is_ereg_8l(u32 reg) | |
167 | { | |
168 | return is_ereg(reg) || | |
169 | (1 << reg) & (BIT(BPF_REG_1) | | |
170 | BIT(BPF_REG_2) | | |
171 | BIT(BPF_REG_FP)); | |
172 | } | |
173 | ||
de0a444d DB |
174 | static bool is_axreg(u32 reg) |
175 | { | |
176 | return reg == BPF_REG_0; | |
177 | } | |
178 | ||
a2c7a983 | 179 | /* Add modifiers if 'reg' maps to x86-64 registers R8..R15 */ |
5cccc702 | 180 | static u8 add_1mod(u8 byte, u32 reg) |
62258278 AS |
181 | { |
182 | if (is_ereg(reg)) | |
183 | byte |= 1; | |
184 | return byte; | |
185 | } | |
186 | ||
5cccc702 | 187 | static u8 add_2mod(u8 byte, u32 r1, u32 r2) |
62258278 AS |
188 | { |
189 | if (is_ereg(r1)) | |
190 | byte |= 1; | |
191 | if (is_ereg(r2)) | |
192 | byte |= 4; | |
193 | return byte; | |
194 | } | |
195 | ||
a2c7a983 | 196 | /* Encode 'dst_reg' register into x86-64 opcode 'byte' */ |
5cccc702 | 197 | static u8 add_1reg(u8 byte, u32 dst_reg) |
62258278 | 198 | { |
e430f34e | 199 | return byte + reg2hex[dst_reg]; |
62258278 AS |
200 | } |
201 | ||
a2c7a983 | 202 | /* Encode 'dst_reg' and 'src_reg' registers into x86-64 opcode 'byte' */ |
5cccc702 | 203 | static u8 add_2reg(u8 byte, u32 dst_reg, u32 src_reg) |
62258278 | 204 | { |
e430f34e | 205 | return byte + reg2hex[dst_reg] + (reg2hex[src_reg] << 3); |
62258278 AS |
206 | } |
207 | ||
e5f02cac BJ |
208 | /* Some 1-byte opcodes for binary ALU operations */ |
209 | static u8 simple_alu_opcodes[] = { | |
210 | [BPF_ADD] = 0x01, | |
211 | [BPF_SUB] = 0x29, | |
212 | [BPF_AND] = 0x21, | |
213 | [BPF_OR] = 0x09, | |
214 | [BPF_XOR] = 0x31, | |
215 | [BPF_LSH] = 0xE0, | |
216 | [BPF_RSH] = 0xE8, | |
217 | [BPF_ARSH] = 0xF8, | |
218 | }; | |
219 | ||
738cbe72 DB |
220 | static void jit_fill_hole(void *area, unsigned int size) |
221 | { | |
a2c7a983 | 222 | /* Fill whole space with INT3 instructions */ |
738cbe72 DB |
223 | memset(area, 0xcc, size); |
224 | } | |
225 | ||
f3c2af7b | 226 | struct jit_context { |
a2c7a983 | 227 | int cleanup_addr; /* Epilogue code offset */ |
f3c2af7b AS |
228 | }; |
229 | ||
a2c7a983 | 230 | /* Maximum number of bytes emitted while JITing one eBPF insn */ |
e0ee9c12 AS |
231 | #define BPF_MAX_INSN_SIZE 128 |
232 | #define BPF_INSN_SAFETY 64 | |
4b3da77b DB |
233 | |
234 | /* Number of bytes emit_patch() needs to generate instructions */ | |
235 | #define X86_PATCH_SIZE 5 | |
ebf7d1f5 MF |
236 | /* Number of bytes that will be skipped on tailcall */ |
237 | #define X86_TAIL_CALL_OFFSET 11 | |
e0ee9c12 | 238 | |
ebf7d1f5 MF |
239 | static void push_callee_regs(u8 **pprog, bool *callee_regs_used) |
240 | { | |
241 | u8 *prog = *pprog; | |
242 | int cnt = 0; | |
243 | ||
244 | if (callee_regs_used[0]) | |
245 | EMIT1(0x53); /* push rbx */ | |
246 | if (callee_regs_used[1]) | |
247 | EMIT2(0x41, 0x55); /* push r13 */ | |
248 | if (callee_regs_used[2]) | |
249 | EMIT2(0x41, 0x56); /* push r14 */ | |
250 | if (callee_regs_used[3]) | |
251 | EMIT2(0x41, 0x57); /* push r15 */ | |
252 | *pprog = prog; | |
253 | } | |
254 | ||
255 | static void pop_callee_regs(u8 **pprog, bool *callee_regs_used) | |
256 | { | |
257 | u8 *prog = *pprog; | |
258 | int cnt = 0; | |
259 | ||
260 | if (callee_regs_used[3]) | |
261 | EMIT2(0x41, 0x5F); /* pop r15 */ | |
262 | if (callee_regs_used[2]) | |
263 | EMIT2(0x41, 0x5E); /* pop r14 */ | |
264 | if (callee_regs_used[1]) | |
265 | EMIT2(0x41, 0x5D); /* pop r13 */ | |
266 | if (callee_regs_used[0]) | |
267 | EMIT1(0x5B); /* pop rbx */ | |
268 | *pprog = prog; | |
269 | } | |
b52f00e6 | 270 | |
a2c7a983 | 271 | /* |
ebf7d1f5 MF |
272 | * Emit x86-64 prologue code for BPF program. |
273 | * bpf_tail_call helper will skip the first X86_TAIL_CALL_OFFSET bytes | |
274 | * while jumping to another program | |
b52f00e6 | 275 | */ |
ebf7d1f5 MF |
276 | static void emit_prologue(u8 **pprog, u32 stack_depth, bool ebpf_from_cbpf, |
277 | bool tail_call_reachable, bool is_subprog) | |
0a14842f | 278 | { |
b52f00e6 | 279 | u8 *prog = *pprog; |
4b3da77b | 280 | int cnt = X86_PATCH_SIZE; |
0a14842f | 281 | |
9fd4a39d AS |
282 | /* BPF trampoline can be made to work without these nops, |
283 | * but let's waste 5 bytes for now and optimize later | |
284 | */ | |
285 | memcpy(prog, ideal_nops[NOP_ATOMIC5], cnt); | |
286 | prog += cnt; | |
ebf7d1f5 MF |
287 | if (!ebpf_from_cbpf) { |
288 | if (tail_call_reachable && !is_subprog) | |
289 | EMIT2(0x31, 0xC0); /* xor eax, eax */ | |
290 | else | |
291 | EMIT2(0x66, 0x90); /* nop2 */ | |
292 | } | |
fe8d9571 AS |
293 | EMIT1(0x55); /* push rbp */ |
294 | EMIT3(0x48, 0x89, 0xE5); /* mov rbp, rsp */ | |
295 | /* sub rsp, rounded_stack_depth */ | |
4d0b8c0b MF |
296 | if (stack_depth) |
297 | EMIT3_off32(0x48, 0x81, 0xEC, round_up(stack_depth, 8)); | |
ebf7d1f5 MF |
298 | if (tail_call_reachable) |
299 | EMIT1(0x50); /* push rax */ | |
b52f00e6 AS |
300 | *pprog = prog; |
301 | } | |
302 | ||
428d5df1 DB |
303 | static int emit_patch(u8 **pprog, void *func, void *ip, u8 opcode) |
304 | { | |
305 | u8 *prog = *pprog; | |
306 | int cnt = 0; | |
307 | s64 offset; | |
308 | ||
309 | offset = func - (ip + X86_PATCH_SIZE); | |
310 | if (!is_simm32(offset)) { | |
311 | pr_err("Target call %p is out of range\n", func); | |
312 | return -ERANGE; | |
313 | } | |
314 | EMIT1_off32(opcode, offset); | |
315 | *pprog = prog; | |
316 | return 0; | |
317 | } | |
318 | ||
319 | static int emit_call(u8 **pprog, void *func, void *ip) | |
320 | { | |
321 | return emit_patch(pprog, func, ip, 0xE8); | |
322 | } | |
323 | ||
324 | static int emit_jump(u8 **pprog, void *func, void *ip) | |
325 | { | |
326 | return emit_patch(pprog, func, ip, 0xE9); | |
327 | } | |
328 | ||
329 | static int __bpf_arch_text_poke(void *ip, enum bpf_text_poke_type t, | |
330 | void *old_addr, void *new_addr, | |
331 | const bool text_live) | |
332 | { | |
428d5df1 | 333 | const u8 *nop_insn = ideal_nops[NOP_ATOMIC5]; |
b553a6ec DB |
334 | u8 old_insn[X86_PATCH_SIZE]; |
335 | u8 new_insn[X86_PATCH_SIZE]; | |
428d5df1 DB |
336 | u8 *prog; |
337 | int ret; | |
338 | ||
b553a6ec DB |
339 | memcpy(old_insn, nop_insn, X86_PATCH_SIZE); |
340 | if (old_addr) { | |
341 | prog = old_insn; | |
342 | ret = t == BPF_MOD_CALL ? | |
343 | emit_call(&prog, old_addr, ip) : | |
344 | emit_jump(&prog, old_addr, ip); | |
345 | if (ret) | |
346 | return ret; | |
428d5df1 DB |
347 | } |
348 | ||
b553a6ec DB |
349 | memcpy(new_insn, nop_insn, X86_PATCH_SIZE); |
350 | if (new_addr) { | |
351 | prog = new_insn; | |
352 | ret = t == BPF_MOD_CALL ? | |
353 | emit_call(&prog, new_addr, ip) : | |
354 | emit_jump(&prog, new_addr, ip); | |
355 | if (ret) | |
356 | return ret; | |
428d5df1 DB |
357 | } |
358 | ||
359 | ret = -EBUSY; | |
360 | mutex_lock(&text_mutex); | |
361 | if (memcmp(ip, old_insn, X86_PATCH_SIZE)) | |
362 | goto out; | |
ebf7d1f5 | 363 | ret = 1; |
b553a6ec DB |
364 | if (memcmp(ip, new_insn, X86_PATCH_SIZE)) { |
365 | if (text_live) | |
366 | text_poke_bp(ip, new_insn, X86_PATCH_SIZE, NULL); | |
367 | else | |
368 | memcpy(ip, new_insn, X86_PATCH_SIZE); | |
ebf7d1f5 | 369 | ret = 0; |
b553a6ec | 370 | } |
428d5df1 DB |
371 | out: |
372 | mutex_unlock(&text_mutex); | |
373 | return ret; | |
374 | } | |
375 | ||
376 | int bpf_arch_text_poke(void *ip, enum bpf_text_poke_type t, | |
377 | void *old_addr, void *new_addr) | |
378 | { | |
379 | if (!is_kernel_text((long)ip) && | |
380 | !is_bpf_text_address((long)ip)) | |
381 | /* BPF poking in modules is not supported */ | |
382 | return -EINVAL; | |
383 | ||
384 | return __bpf_arch_text_poke(ip, t, old_addr, new_addr, true); | |
385 | } | |
386 | ||
ebf7d1f5 MF |
387 | static int get_pop_bytes(bool *callee_regs_used) |
388 | { | |
389 | int bytes = 0; | |
390 | ||
391 | if (callee_regs_used[3]) | |
392 | bytes += 2; | |
393 | if (callee_regs_used[2]) | |
394 | bytes += 2; | |
395 | if (callee_regs_used[1]) | |
396 | bytes += 2; | |
397 | if (callee_regs_used[0]) | |
398 | bytes += 1; | |
399 | ||
400 | return bytes; | |
401 | } | |
402 | ||
a2c7a983 IM |
403 | /* |
404 | * Generate the following code: | |
405 | * | |
b52f00e6 AS |
406 | * ... bpf_tail_call(void *ctx, struct bpf_array *array, u64 index) ... |
407 | * if (index >= array->map.max_entries) | |
408 | * goto out; | |
409 | * if (++tail_call_cnt > MAX_TAIL_CALL_CNT) | |
410 | * goto out; | |
2a36f0b9 | 411 | * prog = array->ptrs[index]; |
b52f00e6 AS |
412 | * if (prog == NULL) |
413 | * goto out; | |
414 | * goto *(prog->bpf_func + prologue_size); | |
415 | * out: | |
416 | */ | |
ebf7d1f5 MF |
417 | static void emit_bpf_tail_call_indirect(u8 **pprog, bool *callee_regs_used, |
418 | u32 stack_depth) | |
b52f00e6 | 419 | { |
ebf7d1f5 | 420 | int tcc_off = -4 - round_up(stack_depth, 8); |
b52f00e6 | 421 | u8 *prog = *pprog; |
ebf7d1f5 | 422 | int pop_bytes = 0; |
4d0b8c0b MF |
423 | int off1 = 42; |
424 | int off2 = 31; | |
425 | int off3 = 9; | |
b52f00e6 AS |
426 | int cnt = 0; |
427 | ||
ebf7d1f5 MF |
428 | /* count the additional bytes used for popping callee regs from stack |
429 | * that need to be taken into account for each of the offsets that | |
430 | * are used for bailing out of the tail call | |
431 | */ | |
432 | pop_bytes = get_pop_bytes(callee_regs_used); | |
433 | off1 += pop_bytes; | |
434 | off2 += pop_bytes; | |
435 | off3 += pop_bytes; | |
436 | ||
4d0b8c0b MF |
437 | if (stack_depth) { |
438 | off1 += 7; | |
439 | off2 += 7; | |
440 | off3 += 7; | |
441 | } | |
442 | ||
a2c7a983 IM |
443 | /* |
444 | * rdi - pointer to ctx | |
b52f00e6 AS |
445 | * rsi - pointer to bpf_array |
446 | * rdx - index in bpf_array | |
447 | */ | |
448 | ||
a2c7a983 IM |
449 | /* |
450 | * if (index >= array->map.max_entries) | |
451 | * goto out; | |
b52f00e6 | 452 | */ |
90caccdd AS |
453 | EMIT2(0x89, 0xD2); /* mov edx, edx */ |
454 | EMIT3(0x39, 0x56, /* cmp dword ptr [rsi + 16], edx */ | |
b52f00e6 | 455 | offsetof(struct bpf_array, map.max_entries)); |
ebf7d1f5 | 456 | #define OFFSET1 (off1 + RETPOLINE_RCX_BPF_JIT_SIZE) /* Number of bytes to jump */ |
b52f00e6 | 457 | EMIT2(X86_JBE, OFFSET1); /* jbe out */ |
b52f00e6 | 458 | |
a2c7a983 IM |
459 | /* |
460 | * if (tail_call_cnt > MAX_TAIL_CALL_CNT) | |
461 | * goto out; | |
b52f00e6 | 462 | */ |
ebf7d1f5 | 463 | EMIT2_off32(0x8B, 0x85, tcc_off); /* mov eax, dword ptr [rbp - tcc_off] */ |
b52f00e6 | 464 | EMIT3(0x83, 0xF8, MAX_TAIL_CALL_CNT); /* cmp eax, MAX_TAIL_CALL_CNT */ |
ebf7d1f5 | 465 | #define OFFSET2 (off2 + RETPOLINE_RCX_BPF_JIT_SIZE) |
b52f00e6 | 466 | EMIT2(X86_JA, OFFSET2); /* ja out */ |
b52f00e6 | 467 | EMIT3(0x83, 0xC0, 0x01); /* add eax, 1 */ |
ebf7d1f5 | 468 | EMIT2_off32(0x89, 0x85, tcc_off); /* mov dword ptr [rbp - tcc_off], eax */ |
b52f00e6 | 469 | |
2a36f0b9 | 470 | /* prog = array->ptrs[index]; */ |
0d4ddce3 | 471 | EMIT4_off32(0x48, 0x8B, 0x8C, 0xD6, /* mov rcx, [rsi + rdx * 8 + offsetof(...)] */ |
2a36f0b9 | 472 | offsetof(struct bpf_array, ptrs)); |
b52f00e6 | 473 | |
a2c7a983 IM |
474 | /* |
475 | * if (prog == NULL) | |
476 | * goto out; | |
b52f00e6 | 477 | */ |
ebf7d1f5 MF |
478 | EMIT3(0x48, 0x85, 0xC9); /* test rcx,rcx */ |
479 | #define OFFSET3 (off3 + RETPOLINE_RCX_BPF_JIT_SIZE) | |
b52f00e6 | 480 | EMIT2(X86_JE, OFFSET3); /* je out */ |
b52f00e6 | 481 | |
ebf7d1f5 MF |
482 | *pprog = prog; |
483 | pop_callee_regs(pprog, callee_regs_used); | |
484 | prog = *pprog; | |
485 | ||
486 | EMIT1(0x58); /* pop rax */ | |
4d0b8c0b MF |
487 | if (stack_depth) |
488 | EMIT3_off32(0x48, 0x81, 0xC4, /* add rsp, sd */ | |
489 | round_up(stack_depth, 8)); | |
ebf7d1f5 MF |
490 | |
491 | /* goto *(prog->bpf_func + X86_TAIL_CALL_OFFSET); */ | |
0d4ddce3 | 492 | EMIT4(0x48, 0x8B, 0x49, /* mov rcx, qword ptr [rcx + 32] */ |
b52f00e6 | 493 | offsetof(struct bpf_prog, bpf_func)); |
ebf7d1f5 MF |
494 | EMIT4(0x48, 0x83, 0xC1, /* add rcx, X86_TAIL_CALL_OFFSET */ |
495 | X86_TAIL_CALL_OFFSET); | |
a2c7a983 | 496 | /* |
0d4ddce3 | 497 | * Now we're ready to jump into next BPF program |
b52f00e6 | 498 | * rdi == ctx (1st arg) |
ebf7d1f5 | 499 | * rcx == prog->bpf_func + X86_TAIL_CALL_OFFSET |
b52f00e6 | 500 | */ |
0d4ddce3 | 501 | RETPOLINE_RCX_BPF_JIT(); |
b52f00e6 AS |
502 | |
503 | /* out: */ | |
b52f00e6 AS |
504 | *pprog = prog; |
505 | } | |
506 | ||
428d5df1 | 507 | static void emit_bpf_tail_call_direct(struct bpf_jit_poke_descriptor *poke, |
ebf7d1f5 MF |
508 | u8 **pprog, int addr, u8 *image, |
509 | bool *callee_regs_used, u32 stack_depth) | |
428d5df1 | 510 | { |
ebf7d1f5 | 511 | int tcc_off = -4 - round_up(stack_depth, 8); |
428d5df1 | 512 | u8 *prog = *pprog; |
ebf7d1f5 | 513 | int pop_bytes = 0; |
4d0b8c0b | 514 | int off1 = 20; |
ebf7d1f5 | 515 | int poke_off; |
428d5df1 DB |
516 | int cnt = 0; |
517 | ||
ebf7d1f5 MF |
518 | /* count the additional bytes used for popping callee regs to stack |
519 | * that need to be taken into account for jump offset that is used for | |
520 | * bailing out from of the tail call when limit is reached | |
521 | */ | |
522 | pop_bytes = get_pop_bytes(callee_regs_used); | |
523 | off1 += pop_bytes; | |
524 | ||
525 | /* | |
526 | * total bytes for: | |
527 | * - nop5/ jmpq $off | |
528 | * - pop callee regs | |
4d0b8c0b | 529 | * - sub rsp, $val if depth > 0 |
ebf7d1f5 MF |
530 | * - pop rax |
531 | */ | |
4d0b8c0b MF |
532 | poke_off = X86_PATCH_SIZE + pop_bytes + 1; |
533 | if (stack_depth) { | |
534 | poke_off += 7; | |
535 | off1 += 7; | |
536 | } | |
ebf7d1f5 | 537 | |
428d5df1 DB |
538 | /* |
539 | * if (tail_call_cnt > MAX_TAIL_CALL_CNT) | |
540 | * goto out; | |
541 | */ | |
ebf7d1f5 | 542 | EMIT2_off32(0x8B, 0x85, tcc_off); /* mov eax, dword ptr [rbp - tcc_off] */ |
428d5df1 | 543 | EMIT3(0x83, 0xF8, MAX_TAIL_CALL_CNT); /* cmp eax, MAX_TAIL_CALL_CNT */ |
ebf7d1f5 | 544 | EMIT2(X86_JA, off1); /* ja out */ |
428d5df1 | 545 | EMIT3(0x83, 0xC0, 0x01); /* add eax, 1 */ |
ebf7d1f5 | 546 | EMIT2_off32(0x89, 0x85, tcc_off); /* mov dword ptr [rbp - tcc_off], eax */ |
428d5df1 | 547 | |
ebf7d1f5 MF |
548 | poke->tailcall_bypass = image + (addr - poke_off - X86_PATCH_SIZE); |
549 | poke->adj_off = X86_TAIL_CALL_OFFSET; | |
cf71b174 | 550 | poke->tailcall_target = image + (addr - X86_PATCH_SIZE); |
ebf7d1f5 MF |
551 | poke->bypass_addr = (u8 *)poke->tailcall_target + X86_PATCH_SIZE; |
552 | ||
553 | emit_jump(&prog, (u8 *)poke->tailcall_target + X86_PATCH_SIZE, | |
554 | poke->tailcall_bypass); | |
555 | ||
556 | *pprog = prog; | |
557 | pop_callee_regs(pprog, callee_regs_used); | |
558 | prog = *pprog; | |
559 | EMIT1(0x58); /* pop rax */ | |
4d0b8c0b MF |
560 | if (stack_depth) |
561 | EMIT3_off32(0x48, 0x81, 0xC4, round_up(stack_depth, 8)); | |
428d5df1 DB |
562 | |
563 | memcpy(prog, ideal_nops[NOP_ATOMIC5], X86_PATCH_SIZE); | |
564 | prog += X86_PATCH_SIZE; | |
565 | /* out: */ | |
566 | ||
567 | *pprog = prog; | |
568 | } | |
569 | ||
570 | static void bpf_tail_call_direct_fixup(struct bpf_prog *prog) | |
571 | { | |
428d5df1 DB |
572 | struct bpf_jit_poke_descriptor *poke; |
573 | struct bpf_array *array; | |
574 | struct bpf_prog *target; | |
575 | int i, ret; | |
576 | ||
577 | for (i = 0; i < prog->aux->size_poke_tab; i++) { | |
578 | poke = &prog->aux->poke_tab[i]; | |
cf71b174 | 579 | WARN_ON_ONCE(READ_ONCE(poke->tailcall_target_stable)); |
428d5df1 DB |
580 | |
581 | if (poke->reason != BPF_POKE_REASON_TAIL_CALL) | |
582 | continue; | |
583 | ||
584 | array = container_of(poke->tail_call.map, struct bpf_array, map); | |
585 | mutex_lock(&array->aux->poke_mutex); | |
586 | target = array->ptrs[poke->tail_call.key]; | |
587 | if (target) { | |
588 | /* Plain memcpy is used when image is not live yet | |
589 | * and still not locked as read-only. Once poke | |
cf71b174 MF |
590 | * location is active (poke->tailcall_target_stable), |
591 | * any parallel bpf_arch_text_poke() might occur | |
592 | * still on the read-write image until we finally | |
593 | * locked it as read-only. Both modifications on | |
594 | * the given image are under text_mutex to avoid | |
595 | * interference. | |
428d5df1 | 596 | */ |
cf71b174 MF |
597 | ret = __bpf_arch_text_poke(poke->tailcall_target, |
598 | BPF_MOD_JUMP, NULL, | |
428d5df1 DB |
599 | (u8 *)target->bpf_func + |
600 | poke->adj_off, false); | |
601 | BUG_ON(ret < 0); | |
ebf7d1f5 MF |
602 | ret = __bpf_arch_text_poke(poke->tailcall_bypass, |
603 | BPF_MOD_JUMP, | |
604 | (u8 *)poke->tailcall_target + | |
605 | X86_PATCH_SIZE, NULL, false); | |
606 | BUG_ON(ret < 0); | |
428d5df1 | 607 | } |
cf71b174 | 608 | WRITE_ONCE(poke->tailcall_target_stable, true); |
428d5df1 DB |
609 | mutex_unlock(&array->aux->poke_mutex); |
610 | } | |
611 | } | |
612 | ||
6fe8b9c1 DB |
613 | static void emit_mov_imm32(u8 **pprog, bool sign_propagate, |
614 | u32 dst_reg, const u32 imm32) | |
615 | { | |
616 | u8 *prog = *pprog; | |
617 | u8 b1, b2, b3; | |
618 | int cnt = 0; | |
619 | ||
a2c7a983 IM |
620 | /* |
621 | * Optimization: if imm32 is positive, use 'mov %eax, imm32' | |
6fe8b9c1 DB |
622 | * (which zero-extends imm32) to save 2 bytes. |
623 | */ | |
624 | if (sign_propagate && (s32)imm32 < 0) { | |
625 | /* 'mov %rax, imm32' sign extends imm32 */ | |
626 | b1 = add_1mod(0x48, dst_reg); | |
627 | b2 = 0xC7; | |
628 | b3 = 0xC0; | |
629 | EMIT3_off32(b1, b2, add_1reg(b3, dst_reg), imm32); | |
630 | goto done; | |
631 | } | |
632 | ||
a2c7a983 IM |
633 | /* |
634 | * Optimization: if imm32 is zero, use 'xor %eax, %eax' | |
6fe8b9c1 DB |
635 | * to save 3 bytes. |
636 | */ | |
637 | if (imm32 == 0) { | |
638 | if (is_ereg(dst_reg)) | |
639 | EMIT1(add_2mod(0x40, dst_reg, dst_reg)); | |
640 | b2 = 0x31; /* xor */ | |
641 | b3 = 0xC0; | |
642 | EMIT2(b2, add_2reg(b3, dst_reg, dst_reg)); | |
643 | goto done; | |
644 | } | |
645 | ||
646 | /* mov %eax, imm32 */ | |
647 | if (is_ereg(dst_reg)) | |
648 | EMIT1(add_1mod(0x40, dst_reg)); | |
649 | EMIT1_off32(add_1reg(0xB8, dst_reg), imm32); | |
650 | done: | |
651 | *pprog = prog; | |
652 | } | |
653 | ||
654 | static void emit_mov_imm64(u8 **pprog, u32 dst_reg, | |
655 | const u32 imm32_hi, const u32 imm32_lo) | |
656 | { | |
657 | u8 *prog = *pprog; | |
658 | int cnt = 0; | |
659 | ||
660 | if (is_uimm32(((u64)imm32_hi << 32) | (u32)imm32_lo)) { | |
a2c7a983 IM |
661 | /* |
662 | * For emitting plain u32, where sign bit must not be | |
6fe8b9c1 DB |
663 | * propagated LLVM tends to load imm64 over mov32 |
664 | * directly, so save couple of bytes by just doing | |
665 | * 'mov %eax, imm32' instead. | |
666 | */ | |
667 | emit_mov_imm32(&prog, false, dst_reg, imm32_lo); | |
668 | } else { | |
669 | /* movabsq %rax, imm64 */ | |
670 | EMIT2(add_1mod(0x48, dst_reg), add_1reg(0xB8, dst_reg)); | |
671 | EMIT(imm32_lo, 4); | |
672 | EMIT(imm32_hi, 4); | |
673 | } | |
674 | ||
675 | *pprog = prog; | |
676 | } | |
677 | ||
4c38e2f3 DB |
678 | static void emit_mov_reg(u8 **pprog, bool is64, u32 dst_reg, u32 src_reg) |
679 | { | |
680 | u8 *prog = *pprog; | |
681 | int cnt = 0; | |
682 | ||
683 | if (is64) { | |
684 | /* mov dst, src */ | |
685 | EMIT_mov(dst_reg, src_reg); | |
686 | } else { | |
687 | /* mov32 dst, src */ | |
688 | if (is_ereg(dst_reg) || is_ereg(src_reg)) | |
689 | EMIT1(add_2mod(0x40, dst_reg, src_reg)); | |
690 | EMIT2(0x89, add_2reg(0xC0, dst_reg, src_reg)); | |
691 | } | |
692 | ||
693 | *pprog = prog; | |
694 | } | |
695 | ||
11c11d07 BJ |
696 | /* Emit the suffix (ModR/M etc) for addressing *(ptr_reg + off) and val_reg */ |
697 | static void emit_insn_suffix(u8 **pprog, u32 ptr_reg, u32 val_reg, int off) | |
698 | { | |
699 | u8 *prog = *pprog; | |
700 | int cnt = 0; | |
701 | ||
702 | if (is_imm8(off)) { | |
703 | /* 1-byte signed displacement. | |
704 | * | |
705 | * If off == 0 we could skip this and save one extra byte, but | |
706 | * special case of x86 R13 which always needs an offset is not | |
707 | * worth the hassle | |
708 | */ | |
709 | EMIT2(add_2reg(0x40, ptr_reg, val_reg), off); | |
710 | } else { | |
711 | /* 4-byte signed displacement */ | |
712 | EMIT1_off32(add_2reg(0x80, ptr_reg, val_reg), off); | |
713 | } | |
714 | *pprog = prog; | |
715 | } | |
716 | ||
74007cfc BJ |
717 | /* |
718 | * Emit a REX byte if it will be necessary to address these registers | |
719 | */ | |
720 | static void maybe_emit_mod(u8 **pprog, u32 dst_reg, u32 src_reg, bool is64) | |
721 | { | |
722 | u8 *prog = *pprog; | |
723 | int cnt = 0; | |
724 | ||
725 | if (is64) | |
726 | EMIT1(add_2mod(0x48, dst_reg, src_reg)); | |
727 | else if (is_ereg(dst_reg) || is_ereg(src_reg)) | |
728 | EMIT1(add_2mod(0x40, dst_reg, src_reg)); | |
729 | *pprog = prog; | |
730 | } | |
731 | ||
3b2744e6 AS |
732 | /* LDX: dst_reg = *(u8*)(src_reg + off) */ |
733 | static void emit_ldx(u8 **pprog, u32 size, u32 dst_reg, u32 src_reg, int off) | |
734 | { | |
735 | u8 *prog = *pprog; | |
736 | int cnt = 0; | |
737 | ||
738 | switch (size) { | |
739 | case BPF_B: | |
740 | /* Emit 'movzx rax, byte ptr [rax + off]' */ | |
741 | EMIT3(add_2mod(0x48, src_reg, dst_reg), 0x0F, 0xB6); | |
742 | break; | |
743 | case BPF_H: | |
744 | /* Emit 'movzx rax, word ptr [rax + off]' */ | |
745 | EMIT3(add_2mod(0x48, src_reg, dst_reg), 0x0F, 0xB7); | |
746 | break; | |
747 | case BPF_W: | |
748 | /* Emit 'mov eax, dword ptr [rax+0x14]' */ | |
749 | if (is_ereg(dst_reg) || is_ereg(src_reg)) | |
750 | EMIT2(add_2mod(0x40, src_reg, dst_reg), 0x8B); | |
751 | else | |
752 | EMIT1(0x8B); | |
753 | break; | |
754 | case BPF_DW: | |
755 | /* Emit 'mov rax, qword ptr [rax+0x14]' */ | |
756 | EMIT2(add_2mod(0x48, src_reg, dst_reg), 0x8B); | |
757 | break; | |
758 | } | |
11c11d07 | 759 | emit_insn_suffix(&prog, src_reg, dst_reg, off); |
3b2744e6 AS |
760 | *pprog = prog; |
761 | } | |
762 | ||
763 | /* STX: *(u8*)(dst_reg + off) = src_reg */ | |
764 | static void emit_stx(u8 **pprog, u32 size, u32 dst_reg, u32 src_reg, int off) | |
765 | { | |
766 | u8 *prog = *pprog; | |
767 | int cnt = 0; | |
768 | ||
769 | switch (size) { | |
770 | case BPF_B: | |
771 | /* Emit 'mov byte ptr [rax + off], al' */ | |
aee194b1 LN |
772 | if (is_ereg(dst_reg) || is_ereg_8l(src_reg)) |
773 | /* Add extra byte for eregs or SIL,DIL,BPL in src_reg */ | |
3b2744e6 AS |
774 | EMIT2(add_2mod(0x40, dst_reg, src_reg), 0x88); |
775 | else | |
776 | EMIT1(0x88); | |
777 | break; | |
778 | case BPF_H: | |
779 | if (is_ereg(dst_reg) || is_ereg(src_reg)) | |
780 | EMIT3(0x66, add_2mod(0x40, dst_reg, src_reg), 0x89); | |
781 | else | |
782 | EMIT2(0x66, 0x89); | |
783 | break; | |
784 | case BPF_W: | |
785 | if (is_ereg(dst_reg) || is_ereg(src_reg)) | |
786 | EMIT2(add_2mod(0x40, dst_reg, src_reg), 0x89); | |
787 | else | |
788 | EMIT1(0x89); | |
789 | break; | |
790 | case BPF_DW: | |
791 | EMIT2(add_2mod(0x48, dst_reg, src_reg), 0x89); | |
792 | break; | |
793 | } | |
11c11d07 | 794 | emit_insn_suffix(&prog, dst_reg, src_reg, off); |
3b2744e6 AS |
795 | *pprog = prog; |
796 | } | |
797 | ||
91c960b0 BJ |
798 | static int emit_atomic(u8 **pprog, u8 atomic_op, |
799 | u32 dst_reg, u32 src_reg, s16 off, u8 bpf_size) | |
800 | { | |
801 | u8 *prog = *pprog; | |
802 | int cnt = 0; | |
803 | ||
804 | EMIT1(0xF0); /* lock prefix */ | |
805 | ||
806 | maybe_emit_mod(&prog, dst_reg, src_reg, bpf_size == BPF_DW); | |
807 | ||
808 | /* emit opcode */ | |
809 | switch (atomic_op) { | |
810 | case BPF_ADD: | |
811 | /* lock *(u32/u64*)(dst_reg + off) <op>= src_reg */ | |
812 | EMIT1(simple_alu_opcodes[atomic_op]); | |
813 | break; | |
814 | default: | |
815 | pr_err("bpf_jit: unknown atomic opcode %02x\n", atomic_op); | |
816 | return -EFAULT; | |
817 | } | |
818 | ||
819 | emit_insn_suffix(&prog, dst_reg, src_reg, off); | |
820 | ||
821 | *pprog = prog; | |
822 | return 0; | |
823 | } | |
824 | ||
3dec541b AS |
825 | static bool ex_handler_bpf(const struct exception_table_entry *x, |
826 | struct pt_regs *regs, int trapnr, | |
827 | unsigned long error_code, unsigned long fault_addr) | |
828 | { | |
829 | u32 reg = x->fixup >> 8; | |
830 | ||
831 | /* jump over faulting load and clear dest register */ | |
832 | *(unsigned long *)((void *)regs + reg) = 0; | |
833 | regs->ip += x->fixup & 0xff; | |
834 | return true; | |
835 | } | |
836 | ||
ebf7d1f5 MF |
837 | static void detect_reg_usage(struct bpf_insn *insn, int insn_cnt, |
838 | bool *regs_used, bool *tail_call_seen) | |
839 | { | |
840 | int i; | |
841 | ||
842 | for (i = 1; i <= insn_cnt; i++, insn++) { | |
843 | if (insn->code == (BPF_JMP | BPF_TAIL_CALL)) | |
844 | *tail_call_seen = true; | |
845 | if (insn->dst_reg == BPF_REG_6 || insn->src_reg == BPF_REG_6) | |
846 | regs_used[0] = true; | |
847 | if (insn->dst_reg == BPF_REG_7 || insn->src_reg == BPF_REG_7) | |
848 | regs_used[1] = true; | |
849 | if (insn->dst_reg == BPF_REG_8 || insn->src_reg == BPF_REG_8) | |
850 | regs_used[2] = true; | |
851 | if (insn->dst_reg == BPF_REG_9 || insn->src_reg == BPF_REG_9) | |
852 | regs_used[3] = true; | |
853 | } | |
854 | } | |
855 | ||
b52f00e6 AS |
856 | static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image, |
857 | int oldproglen, struct jit_context *ctx) | |
858 | { | |
ebf7d1f5 | 859 | bool tail_call_reachable = bpf_prog->aux->tail_call_reachable; |
b52f00e6 | 860 | struct bpf_insn *insn = bpf_prog->insnsi; |
ebf7d1f5 | 861 | bool callee_regs_used[4] = {}; |
b52f00e6 | 862 | int insn_cnt = bpf_prog->len; |
ebf7d1f5 | 863 | bool tail_call_seen = false; |
b52f00e6 AS |
864 | bool seen_exit = false; |
865 | u8 temp[BPF_MAX_INSN_SIZE + BPF_INSN_SAFETY]; | |
3dec541b | 866 | int i, cnt = 0, excnt = 0; |
b52f00e6 AS |
867 | int proglen = 0; |
868 | u8 *prog = temp; | |
91c960b0 | 869 | int err; |
b52f00e6 | 870 | |
ebf7d1f5 MF |
871 | detect_reg_usage(insn, insn_cnt, callee_regs_used, |
872 | &tail_call_seen); | |
873 | ||
874 | /* tail call's presence in current prog implies it is reachable */ | |
875 | tail_call_reachable |= tail_call_seen; | |
876 | ||
08691752 | 877 | emit_prologue(&prog, bpf_prog->aux->stack_depth, |
ebf7d1f5 MF |
878 | bpf_prog_was_classic(bpf_prog), tail_call_reachable, |
879 | bpf_prog->aux->func_idx != 0); | |
880 | push_callee_regs(&prog, callee_regs_used); | |
7c2e988f | 881 | addrs[0] = prog - temp; |
b52f00e6 | 882 | |
7c2e988f | 883 | for (i = 1; i <= insn_cnt; i++, insn++) { |
e430f34e AS |
884 | const s32 imm32 = insn->imm; |
885 | u32 dst_reg = insn->dst_reg; | |
886 | u32 src_reg = insn->src_reg; | |
6fe8b9c1 | 887 | u8 b2 = 0, b3 = 0; |
62258278 AS |
888 | s64 jmp_offset; |
889 | u8 jmp_cond; | |
890 | int ilen; | |
891 | u8 *func; | |
892 | ||
893 | switch (insn->code) { | |
894 | /* ALU */ | |
895 | case BPF_ALU | BPF_ADD | BPF_X: | |
896 | case BPF_ALU | BPF_SUB | BPF_X: | |
897 | case BPF_ALU | BPF_AND | BPF_X: | |
898 | case BPF_ALU | BPF_OR | BPF_X: | |
899 | case BPF_ALU | BPF_XOR | BPF_X: | |
900 | case BPF_ALU64 | BPF_ADD | BPF_X: | |
901 | case BPF_ALU64 | BPF_SUB | BPF_X: | |
902 | case BPF_ALU64 | BPF_AND | BPF_X: | |
903 | case BPF_ALU64 | BPF_OR | BPF_X: | |
904 | case BPF_ALU64 | BPF_XOR | BPF_X: | |
74007cfc BJ |
905 | maybe_emit_mod(&prog, dst_reg, src_reg, |
906 | BPF_CLASS(insn->code) == BPF_ALU64); | |
e5f02cac | 907 | b2 = simple_alu_opcodes[BPF_OP(insn->code)]; |
e430f34e | 908 | EMIT2(b2, add_2reg(0xC0, dst_reg, src_reg)); |
62258278 | 909 | break; |
0a14842f | 910 | |
62258278 | 911 | case BPF_ALU64 | BPF_MOV | BPF_X: |
62258278 | 912 | case BPF_ALU | BPF_MOV | BPF_X: |
4c38e2f3 DB |
913 | emit_mov_reg(&prog, |
914 | BPF_CLASS(insn->code) == BPF_ALU64, | |
915 | dst_reg, src_reg); | |
62258278 | 916 | break; |
0a14842f | 917 | |
e430f34e | 918 | /* neg dst */ |
62258278 AS |
919 | case BPF_ALU | BPF_NEG: |
920 | case BPF_ALU64 | BPF_NEG: | |
921 | if (BPF_CLASS(insn->code) == BPF_ALU64) | |
e430f34e AS |
922 | EMIT1(add_1mod(0x48, dst_reg)); |
923 | else if (is_ereg(dst_reg)) | |
924 | EMIT1(add_1mod(0x40, dst_reg)); | |
925 | EMIT2(0xF7, add_1reg(0xD8, dst_reg)); | |
62258278 AS |
926 | break; |
927 | ||
928 | case BPF_ALU | BPF_ADD | BPF_K: | |
929 | case BPF_ALU | BPF_SUB | BPF_K: | |
930 | case BPF_ALU | BPF_AND | BPF_K: | |
931 | case BPF_ALU | BPF_OR | BPF_K: | |
932 | case BPF_ALU | BPF_XOR | BPF_K: | |
933 | case BPF_ALU64 | BPF_ADD | BPF_K: | |
934 | case BPF_ALU64 | BPF_SUB | BPF_K: | |
935 | case BPF_ALU64 | BPF_AND | BPF_K: | |
936 | case BPF_ALU64 | BPF_OR | BPF_K: | |
937 | case BPF_ALU64 | BPF_XOR | BPF_K: | |
938 | if (BPF_CLASS(insn->code) == BPF_ALU64) | |
e430f34e AS |
939 | EMIT1(add_1mod(0x48, dst_reg)); |
940 | else if (is_ereg(dst_reg)) | |
941 | EMIT1(add_1mod(0x40, dst_reg)); | |
62258278 | 942 | |
a2c7a983 IM |
943 | /* |
944 | * b3 holds 'normal' opcode, b2 short form only valid | |
de0a444d DB |
945 | * in case dst is eax/rax. |
946 | */ | |
62258278 | 947 | switch (BPF_OP(insn->code)) { |
de0a444d DB |
948 | case BPF_ADD: |
949 | b3 = 0xC0; | |
950 | b2 = 0x05; | |
951 | break; | |
952 | case BPF_SUB: | |
953 | b3 = 0xE8; | |
954 | b2 = 0x2D; | |
955 | break; | |
956 | case BPF_AND: | |
957 | b3 = 0xE0; | |
958 | b2 = 0x25; | |
959 | break; | |
960 | case BPF_OR: | |
961 | b3 = 0xC8; | |
962 | b2 = 0x0D; | |
963 | break; | |
964 | case BPF_XOR: | |
965 | b3 = 0xF0; | |
966 | b2 = 0x35; | |
967 | break; | |
62258278 AS |
968 | } |
969 | ||
e430f34e AS |
970 | if (is_imm8(imm32)) |
971 | EMIT3(0x83, add_1reg(b3, dst_reg), imm32); | |
de0a444d DB |
972 | else if (is_axreg(dst_reg)) |
973 | EMIT1_off32(b2, imm32); | |
62258278 | 974 | else |
e430f34e | 975 | EMIT2_off32(0x81, add_1reg(b3, dst_reg), imm32); |
62258278 AS |
976 | break; |
977 | ||
978 | case BPF_ALU64 | BPF_MOV | BPF_K: | |
62258278 | 979 | case BPF_ALU | BPF_MOV | BPF_K: |
6fe8b9c1 DB |
980 | emit_mov_imm32(&prog, BPF_CLASS(insn->code) == BPF_ALU64, |
981 | dst_reg, imm32); | |
62258278 AS |
982 | break; |
983 | ||
02ab695b | 984 | case BPF_LD | BPF_IMM | BPF_DW: |
6fe8b9c1 | 985 | emit_mov_imm64(&prog, dst_reg, insn[1].imm, insn[0].imm); |
02ab695b AS |
986 | insn++; |
987 | i++; | |
988 | break; | |
989 | ||
e430f34e | 990 | /* dst %= src, dst /= src, dst %= imm32, dst /= imm32 */ |
62258278 AS |
991 | case BPF_ALU | BPF_MOD | BPF_X: |
992 | case BPF_ALU | BPF_DIV | BPF_X: | |
993 | case BPF_ALU | BPF_MOD | BPF_K: | |
994 | case BPF_ALU | BPF_DIV | BPF_K: | |
995 | case BPF_ALU64 | BPF_MOD | BPF_X: | |
996 | case BPF_ALU64 | BPF_DIV | BPF_X: | |
997 | case BPF_ALU64 | BPF_MOD | BPF_K: | |
998 | case BPF_ALU64 | BPF_DIV | BPF_K: | |
999 | EMIT1(0x50); /* push rax */ | |
1000 | EMIT1(0x52); /* push rdx */ | |
1001 | ||
1002 | if (BPF_SRC(insn->code) == BPF_X) | |
e430f34e AS |
1003 | /* mov r11, src_reg */ |
1004 | EMIT_mov(AUX_REG, src_reg); | |
62258278 | 1005 | else |
e430f34e AS |
1006 | /* mov r11, imm32 */ |
1007 | EMIT3_off32(0x49, 0xC7, 0xC3, imm32); | |
62258278 | 1008 | |
e430f34e AS |
1009 | /* mov rax, dst_reg */ |
1010 | EMIT_mov(BPF_REG_0, dst_reg); | |
62258278 | 1011 | |
a2c7a983 IM |
1012 | /* |
1013 | * xor edx, edx | |
62258278 AS |
1014 | * equivalent to 'xor rdx, rdx', but one byte less |
1015 | */ | |
1016 | EMIT2(0x31, 0xd2); | |
1017 | ||
62258278 AS |
1018 | if (BPF_CLASS(insn->code) == BPF_ALU64) |
1019 | /* div r11 */ | |
1020 | EMIT3(0x49, 0xF7, 0xF3); | |
1021 | else | |
1022 | /* div r11d */ | |
1023 | EMIT3(0x41, 0xF7, 0xF3); | |
1024 | ||
1025 | if (BPF_OP(insn->code) == BPF_MOD) | |
1026 | /* mov r11, rdx */ | |
1027 | EMIT3(0x49, 0x89, 0xD3); | |
1028 | else | |
1029 | /* mov r11, rax */ | |
1030 | EMIT3(0x49, 0x89, 0xC3); | |
1031 | ||
1032 | EMIT1(0x5A); /* pop rdx */ | |
1033 | EMIT1(0x58); /* pop rax */ | |
1034 | ||
e430f34e AS |
1035 | /* mov dst_reg, r11 */ |
1036 | EMIT_mov(dst_reg, AUX_REG); | |
62258278 AS |
1037 | break; |
1038 | ||
1039 | case BPF_ALU | BPF_MUL | BPF_K: | |
1040 | case BPF_ALU | BPF_MUL | BPF_X: | |
1041 | case BPF_ALU64 | BPF_MUL | BPF_K: | |
1042 | case BPF_ALU64 | BPF_MUL | BPF_X: | |
4c38e2f3 DB |
1043 | { |
1044 | bool is64 = BPF_CLASS(insn->code) == BPF_ALU64; | |
1045 | ||
d806a0cf DB |
1046 | if (dst_reg != BPF_REG_0) |
1047 | EMIT1(0x50); /* push rax */ | |
1048 | if (dst_reg != BPF_REG_3) | |
1049 | EMIT1(0x52); /* push rdx */ | |
62258278 | 1050 | |
e430f34e AS |
1051 | /* mov r11, dst_reg */ |
1052 | EMIT_mov(AUX_REG, dst_reg); | |
62258278 AS |
1053 | |
1054 | if (BPF_SRC(insn->code) == BPF_X) | |
4c38e2f3 | 1055 | emit_mov_reg(&prog, is64, BPF_REG_0, src_reg); |
62258278 | 1056 | else |
4c38e2f3 | 1057 | emit_mov_imm32(&prog, is64, BPF_REG_0, imm32); |
62258278 | 1058 | |
4c38e2f3 | 1059 | if (is64) |
62258278 AS |
1060 | EMIT1(add_1mod(0x48, AUX_REG)); |
1061 | else if (is_ereg(AUX_REG)) | |
1062 | EMIT1(add_1mod(0x40, AUX_REG)); | |
1063 | /* mul(q) r11 */ | |
1064 | EMIT2(0xF7, add_1reg(0xE0, AUX_REG)); | |
1065 | ||
d806a0cf DB |
1066 | if (dst_reg != BPF_REG_3) |
1067 | EMIT1(0x5A); /* pop rdx */ | |
1068 | if (dst_reg != BPF_REG_0) { | |
1069 | /* mov dst_reg, rax */ | |
1070 | EMIT_mov(dst_reg, BPF_REG_0); | |
1071 | EMIT1(0x58); /* pop rax */ | |
1072 | } | |
62258278 | 1073 | break; |
4c38e2f3 | 1074 | } |
a2c7a983 | 1075 | /* Shifts */ |
62258278 AS |
1076 | case BPF_ALU | BPF_LSH | BPF_K: |
1077 | case BPF_ALU | BPF_RSH | BPF_K: | |
1078 | case BPF_ALU | BPF_ARSH | BPF_K: | |
1079 | case BPF_ALU64 | BPF_LSH | BPF_K: | |
1080 | case BPF_ALU64 | BPF_RSH | BPF_K: | |
1081 | case BPF_ALU64 | BPF_ARSH | BPF_K: | |
1082 | if (BPF_CLASS(insn->code) == BPF_ALU64) | |
e430f34e AS |
1083 | EMIT1(add_1mod(0x48, dst_reg)); |
1084 | else if (is_ereg(dst_reg)) | |
1085 | EMIT1(add_1mod(0x40, dst_reg)); | |
62258278 | 1086 | |
e5f02cac | 1087 | b3 = simple_alu_opcodes[BPF_OP(insn->code)]; |
88e69a1f DB |
1088 | if (imm32 == 1) |
1089 | EMIT2(0xD1, add_1reg(b3, dst_reg)); | |
1090 | else | |
1091 | EMIT3(0xC1, add_1reg(b3, dst_reg), imm32); | |
62258278 AS |
1092 | break; |
1093 | ||
72b603ee AS |
1094 | case BPF_ALU | BPF_LSH | BPF_X: |
1095 | case BPF_ALU | BPF_RSH | BPF_X: | |
1096 | case BPF_ALU | BPF_ARSH | BPF_X: | |
1097 | case BPF_ALU64 | BPF_LSH | BPF_X: | |
1098 | case BPF_ALU64 | BPF_RSH | BPF_X: | |
1099 | case BPF_ALU64 | BPF_ARSH | BPF_X: | |
1100 | ||
a2c7a983 | 1101 | /* Check for bad case when dst_reg == rcx */ |
72b603ee AS |
1102 | if (dst_reg == BPF_REG_4) { |
1103 | /* mov r11, dst_reg */ | |
1104 | EMIT_mov(AUX_REG, dst_reg); | |
1105 | dst_reg = AUX_REG; | |
1106 | } | |
1107 | ||
1108 | if (src_reg != BPF_REG_4) { /* common case */ | |
1109 | EMIT1(0x51); /* push rcx */ | |
1110 | ||
1111 | /* mov rcx, src_reg */ | |
1112 | EMIT_mov(BPF_REG_4, src_reg); | |
1113 | } | |
1114 | ||
1115 | /* shl %rax, %cl | shr %rax, %cl | sar %rax, %cl */ | |
1116 | if (BPF_CLASS(insn->code) == BPF_ALU64) | |
1117 | EMIT1(add_1mod(0x48, dst_reg)); | |
1118 | else if (is_ereg(dst_reg)) | |
1119 | EMIT1(add_1mod(0x40, dst_reg)); | |
1120 | ||
e5f02cac | 1121 | b3 = simple_alu_opcodes[BPF_OP(insn->code)]; |
72b603ee AS |
1122 | EMIT2(0xD3, add_1reg(b3, dst_reg)); |
1123 | ||
1124 | if (src_reg != BPF_REG_4) | |
1125 | EMIT1(0x59); /* pop rcx */ | |
1126 | ||
1127 | if (insn->dst_reg == BPF_REG_4) | |
1128 | /* mov dst_reg, r11 */ | |
1129 | EMIT_mov(insn->dst_reg, AUX_REG); | |
1130 | break; | |
1131 | ||
62258278 | 1132 | case BPF_ALU | BPF_END | BPF_FROM_BE: |
e430f34e | 1133 | switch (imm32) { |
62258278 | 1134 | case 16: |
a2c7a983 | 1135 | /* Emit 'ror %ax, 8' to swap lower 2 bytes */ |
62258278 | 1136 | EMIT1(0x66); |
e430f34e | 1137 | if (is_ereg(dst_reg)) |
62258278 | 1138 | EMIT1(0x41); |
e430f34e | 1139 | EMIT3(0xC1, add_1reg(0xC8, dst_reg), 8); |
343f845b | 1140 | |
a2c7a983 | 1141 | /* Emit 'movzwl eax, ax' */ |
343f845b AS |
1142 | if (is_ereg(dst_reg)) |
1143 | EMIT3(0x45, 0x0F, 0xB7); | |
1144 | else | |
1145 | EMIT2(0x0F, 0xB7); | |
1146 | EMIT1(add_2reg(0xC0, dst_reg, dst_reg)); | |
62258278 AS |
1147 | break; |
1148 | case 32: | |
a2c7a983 | 1149 | /* Emit 'bswap eax' to swap lower 4 bytes */ |
e430f34e | 1150 | if (is_ereg(dst_reg)) |
62258278 | 1151 | EMIT2(0x41, 0x0F); |
0a14842f | 1152 | else |
62258278 | 1153 | EMIT1(0x0F); |
e430f34e | 1154 | EMIT1(add_1reg(0xC8, dst_reg)); |
0a14842f | 1155 | break; |
62258278 | 1156 | case 64: |
a2c7a983 | 1157 | /* Emit 'bswap rax' to swap 8 bytes */ |
e430f34e AS |
1158 | EMIT3(add_1mod(0x48, dst_reg), 0x0F, |
1159 | add_1reg(0xC8, dst_reg)); | |
3b58908a ED |
1160 | break; |
1161 | } | |
62258278 AS |
1162 | break; |
1163 | ||
1164 | case BPF_ALU | BPF_END | BPF_FROM_LE: | |
343f845b AS |
1165 | switch (imm32) { |
1166 | case 16: | |
a2c7a983 IM |
1167 | /* |
1168 | * Emit 'movzwl eax, ax' to zero extend 16-bit | |
343f845b AS |
1169 | * into 64 bit |
1170 | */ | |
1171 | if (is_ereg(dst_reg)) | |
1172 | EMIT3(0x45, 0x0F, 0xB7); | |
1173 | else | |
1174 | EMIT2(0x0F, 0xB7); | |
1175 | EMIT1(add_2reg(0xC0, dst_reg, dst_reg)); | |
1176 | break; | |
1177 | case 32: | |
a2c7a983 | 1178 | /* Emit 'mov eax, eax' to clear upper 32-bits */ |
343f845b AS |
1179 | if (is_ereg(dst_reg)) |
1180 | EMIT1(0x45); | |
1181 | EMIT2(0x89, add_2reg(0xC0, dst_reg, dst_reg)); | |
1182 | break; | |
1183 | case 64: | |
1184 | /* nop */ | |
1185 | break; | |
1186 | } | |
62258278 AS |
1187 | break; |
1188 | ||
e430f34e | 1189 | /* ST: *(u8*)(dst_reg + off) = imm */ |
62258278 | 1190 | case BPF_ST | BPF_MEM | BPF_B: |
e430f34e | 1191 | if (is_ereg(dst_reg)) |
62258278 AS |
1192 | EMIT2(0x41, 0xC6); |
1193 | else | |
1194 | EMIT1(0xC6); | |
1195 | goto st; | |
1196 | case BPF_ST | BPF_MEM | BPF_H: | |
e430f34e | 1197 | if (is_ereg(dst_reg)) |
62258278 AS |
1198 | EMIT3(0x66, 0x41, 0xC7); |
1199 | else | |
1200 | EMIT2(0x66, 0xC7); | |
1201 | goto st; | |
1202 | case BPF_ST | BPF_MEM | BPF_W: | |
e430f34e | 1203 | if (is_ereg(dst_reg)) |
62258278 AS |
1204 | EMIT2(0x41, 0xC7); |
1205 | else | |
1206 | EMIT1(0xC7); | |
1207 | goto st; | |
1208 | case BPF_ST | BPF_MEM | BPF_DW: | |
e430f34e | 1209 | EMIT2(add_1mod(0x48, dst_reg), 0xC7); |
62258278 AS |
1210 | |
1211 | st: if (is_imm8(insn->off)) | |
e430f34e | 1212 | EMIT2(add_1reg(0x40, dst_reg), insn->off); |
62258278 | 1213 | else |
e430f34e | 1214 | EMIT1_off32(add_1reg(0x80, dst_reg), insn->off); |
62258278 | 1215 | |
e430f34e | 1216 | EMIT(imm32, bpf_size_to_x86_bytes(BPF_SIZE(insn->code))); |
62258278 AS |
1217 | break; |
1218 | ||
e430f34e | 1219 | /* STX: *(u8*)(dst_reg + off) = src_reg */ |
62258278 | 1220 | case BPF_STX | BPF_MEM | BPF_B: |
62258278 | 1221 | case BPF_STX | BPF_MEM | BPF_H: |
62258278 | 1222 | case BPF_STX | BPF_MEM | BPF_W: |
62258278 | 1223 | case BPF_STX | BPF_MEM | BPF_DW: |
3b2744e6 | 1224 | emit_stx(&prog, BPF_SIZE(insn->code), dst_reg, src_reg, insn->off); |
62258278 AS |
1225 | break; |
1226 | ||
e430f34e | 1227 | /* LDX: dst_reg = *(u8*)(src_reg + off) */ |
62258278 | 1228 | case BPF_LDX | BPF_MEM | BPF_B: |
3dec541b | 1229 | case BPF_LDX | BPF_PROBE_MEM | BPF_B: |
62258278 | 1230 | case BPF_LDX | BPF_MEM | BPF_H: |
3dec541b | 1231 | case BPF_LDX | BPF_PROBE_MEM | BPF_H: |
62258278 | 1232 | case BPF_LDX | BPF_MEM | BPF_W: |
3dec541b | 1233 | case BPF_LDX | BPF_PROBE_MEM | BPF_W: |
62258278 | 1234 | case BPF_LDX | BPF_MEM | BPF_DW: |
3dec541b | 1235 | case BPF_LDX | BPF_PROBE_MEM | BPF_DW: |
3b2744e6 | 1236 | emit_ldx(&prog, BPF_SIZE(insn->code), dst_reg, src_reg, insn->off); |
3dec541b AS |
1237 | if (BPF_MODE(insn->code) == BPF_PROBE_MEM) { |
1238 | struct exception_table_entry *ex; | |
1239 | u8 *_insn = image + proglen; | |
1240 | s64 delta; | |
1241 | ||
1242 | if (!bpf_prog->aux->extable) | |
1243 | break; | |
1244 | ||
1245 | if (excnt >= bpf_prog->aux->num_exentries) { | |
1246 | pr_err("ex gen bug\n"); | |
1247 | return -EFAULT; | |
1248 | } | |
1249 | ex = &bpf_prog->aux->extable[excnt++]; | |
1250 | ||
1251 | delta = _insn - (u8 *)&ex->insn; | |
1252 | if (!is_simm32(delta)) { | |
1253 | pr_err("extable->insn doesn't fit into 32-bit\n"); | |
1254 | return -EFAULT; | |
1255 | } | |
1256 | ex->insn = delta; | |
1257 | ||
1258 | delta = (u8 *)ex_handler_bpf - (u8 *)&ex->handler; | |
1259 | if (!is_simm32(delta)) { | |
1260 | pr_err("extable->handler doesn't fit into 32-bit\n"); | |
1261 | return -EFAULT; | |
1262 | } | |
1263 | ex->handler = delta; | |
1264 | ||
1265 | if (dst_reg > BPF_REG_9) { | |
1266 | pr_err("verifier error\n"); | |
1267 | return -EFAULT; | |
1268 | } | |
1269 | /* | |
1270 | * Compute size of x86 insn and its target dest x86 register. | |
1271 | * ex_handler_bpf() will use lower 8 bits to adjust | |
1272 | * pt_regs->ip to jump over this x86 instruction | |
1273 | * and upper bits to figure out which pt_regs to zero out. | |
1274 | * End result: x86 insn "mov rbx, qword ptr [rax+0x14]" | |
1275 | * of 4 bytes will be ignored and rbx will be zero inited. | |
1276 | */ | |
1277 | ex->fixup = (prog - temp) | (reg2pt_regs[dst_reg] << 8); | |
1278 | } | |
62258278 AS |
1279 | break; |
1280 | ||
91c960b0 BJ |
1281 | case BPF_STX | BPF_ATOMIC | BPF_W: |
1282 | case BPF_STX | BPF_ATOMIC | BPF_DW: | |
1283 | err = emit_atomic(&prog, insn->imm, dst_reg, src_reg, | |
1284 | insn->off, BPF_SIZE(insn->code)); | |
1285 | if (err) | |
1286 | return err; | |
62258278 AS |
1287 | break; |
1288 | ||
1289 | /* call */ | |
1290 | case BPF_JMP | BPF_CALL: | |
e430f34e | 1291 | func = (u8 *) __bpf_call_base + imm32; |
ebf7d1f5 MF |
1292 | if (tail_call_reachable) { |
1293 | EMIT3_off32(0x48, 0x8B, 0x85, | |
1294 | -(bpf_prog->aux->stack_depth + 8)); | |
1295 | if (!imm32 || emit_call(&prog, func, image + addrs[i - 1] + 7)) | |
1296 | return -EINVAL; | |
1297 | } else { | |
1298 | if (!imm32 || emit_call(&prog, func, image + addrs[i - 1])) | |
1299 | return -EINVAL; | |
1300 | } | |
62258278 AS |
1301 | break; |
1302 | ||
71189fa9 | 1303 | case BPF_JMP | BPF_TAIL_CALL: |
428d5df1 DB |
1304 | if (imm32) |
1305 | emit_bpf_tail_call_direct(&bpf_prog->aux->poke_tab[imm32 - 1], | |
ebf7d1f5 MF |
1306 | &prog, addrs[i], image, |
1307 | callee_regs_used, | |
1308 | bpf_prog->aux->stack_depth); | |
428d5df1 | 1309 | else |
ebf7d1f5 MF |
1310 | emit_bpf_tail_call_indirect(&prog, |
1311 | callee_regs_used, | |
1312 | bpf_prog->aux->stack_depth); | |
b52f00e6 AS |
1313 | break; |
1314 | ||
62258278 AS |
1315 | /* cond jump */ |
1316 | case BPF_JMP | BPF_JEQ | BPF_X: | |
1317 | case BPF_JMP | BPF_JNE | BPF_X: | |
1318 | case BPF_JMP | BPF_JGT | BPF_X: | |
52afc51e | 1319 | case BPF_JMP | BPF_JLT | BPF_X: |
62258278 | 1320 | case BPF_JMP | BPF_JGE | BPF_X: |
52afc51e | 1321 | case BPF_JMP | BPF_JLE | BPF_X: |
62258278 | 1322 | case BPF_JMP | BPF_JSGT | BPF_X: |
52afc51e | 1323 | case BPF_JMP | BPF_JSLT | BPF_X: |
62258278 | 1324 | case BPF_JMP | BPF_JSGE | BPF_X: |
52afc51e | 1325 | case BPF_JMP | BPF_JSLE | BPF_X: |
3f5d6525 JW |
1326 | case BPF_JMP32 | BPF_JEQ | BPF_X: |
1327 | case BPF_JMP32 | BPF_JNE | BPF_X: | |
1328 | case BPF_JMP32 | BPF_JGT | BPF_X: | |
1329 | case BPF_JMP32 | BPF_JLT | BPF_X: | |
1330 | case BPF_JMP32 | BPF_JGE | BPF_X: | |
1331 | case BPF_JMP32 | BPF_JLE | BPF_X: | |
1332 | case BPF_JMP32 | BPF_JSGT | BPF_X: | |
1333 | case BPF_JMP32 | BPF_JSLT | BPF_X: | |
1334 | case BPF_JMP32 | BPF_JSGE | BPF_X: | |
1335 | case BPF_JMP32 | BPF_JSLE | BPF_X: | |
e430f34e | 1336 | /* cmp dst_reg, src_reg */ |
74007cfc BJ |
1337 | maybe_emit_mod(&prog, dst_reg, src_reg, |
1338 | BPF_CLASS(insn->code) == BPF_JMP); | |
3f5d6525 | 1339 | EMIT2(0x39, add_2reg(0xC0, dst_reg, src_reg)); |
62258278 AS |
1340 | goto emit_cond_jmp; |
1341 | ||
1342 | case BPF_JMP | BPF_JSET | BPF_X: | |
3f5d6525 | 1343 | case BPF_JMP32 | BPF_JSET | BPF_X: |
e430f34e | 1344 | /* test dst_reg, src_reg */ |
74007cfc BJ |
1345 | maybe_emit_mod(&prog, dst_reg, src_reg, |
1346 | BPF_CLASS(insn->code) == BPF_JMP); | |
3f5d6525 | 1347 | EMIT2(0x85, add_2reg(0xC0, dst_reg, src_reg)); |
62258278 AS |
1348 | goto emit_cond_jmp; |
1349 | ||
1350 | case BPF_JMP | BPF_JSET | BPF_K: | |
3f5d6525 | 1351 | case BPF_JMP32 | BPF_JSET | BPF_K: |
e430f34e | 1352 | /* test dst_reg, imm32 */ |
3f5d6525 JW |
1353 | if (BPF_CLASS(insn->code) == BPF_JMP) |
1354 | EMIT1(add_1mod(0x48, dst_reg)); | |
1355 | else if (is_ereg(dst_reg)) | |
1356 | EMIT1(add_1mod(0x40, dst_reg)); | |
e430f34e | 1357 | EMIT2_off32(0xF7, add_1reg(0xC0, dst_reg), imm32); |
62258278 AS |
1358 | goto emit_cond_jmp; |
1359 | ||
1360 | case BPF_JMP | BPF_JEQ | BPF_K: | |
1361 | case BPF_JMP | BPF_JNE | BPF_K: | |
1362 | case BPF_JMP | BPF_JGT | BPF_K: | |
52afc51e | 1363 | case BPF_JMP | BPF_JLT | BPF_K: |
62258278 | 1364 | case BPF_JMP | BPF_JGE | BPF_K: |
52afc51e | 1365 | case BPF_JMP | BPF_JLE | BPF_K: |
62258278 | 1366 | case BPF_JMP | BPF_JSGT | BPF_K: |
52afc51e | 1367 | case BPF_JMP | BPF_JSLT | BPF_K: |
62258278 | 1368 | case BPF_JMP | BPF_JSGE | BPF_K: |
52afc51e | 1369 | case BPF_JMP | BPF_JSLE | BPF_K: |
3f5d6525 JW |
1370 | case BPF_JMP32 | BPF_JEQ | BPF_K: |
1371 | case BPF_JMP32 | BPF_JNE | BPF_K: | |
1372 | case BPF_JMP32 | BPF_JGT | BPF_K: | |
1373 | case BPF_JMP32 | BPF_JLT | BPF_K: | |
1374 | case BPF_JMP32 | BPF_JGE | BPF_K: | |
1375 | case BPF_JMP32 | BPF_JLE | BPF_K: | |
1376 | case BPF_JMP32 | BPF_JSGT | BPF_K: | |
1377 | case BPF_JMP32 | BPF_JSLT | BPF_K: | |
1378 | case BPF_JMP32 | BPF_JSGE | BPF_K: | |
1379 | case BPF_JMP32 | BPF_JSLE | BPF_K: | |
38f51c07 DB |
1380 | /* test dst_reg, dst_reg to save one extra byte */ |
1381 | if (imm32 == 0) { | |
74007cfc BJ |
1382 | maybe_emit_mod(&prog, dst_reg, dst_reg, |
1383 | BPF_CLASS(insn->code) == BPF_JMP); | |
38f51c07 DB |
1384 | EMIT2(0x85, add_2reg(0xC0, dst_reg, dst_reg)); |
1385 | goto emit_cond_jmp; | |
1386 | } | |
1387 | ||
e430f34e | 1388 | /* cmp dst_reg, imm8/32 */ |
3f5d6525 JW |
1389 | if (BPF_CLASS(insn->code) == BPF_JMP) |
1390 | EMIT1(add_1mod(0x48, dst_reg)); | |
1391 | else if (is_ereg(dst_reg)) | |
1392 | EMIT1(add_1mod(0x40, dst_reg)); | |
62258278 | 1393 | |
e430f34e AS |
1394 | if (is_imm8(imm32)) |
1395 | EMIT3(0x83, add_1reg(0xF8, dst_reg), imm32); | |
62258278 | 1396 | else |
e430f34e | 1397 | EMIT2_off32(0x81, add_1reg(0xF8, dst_reg), imm32); |
62258278 | 1398 | |
a2c7a983 | 1399 | emit_cond_jmp: /* Convert BPF opcode to x86 */ |
62258278 AS |
1400 | switch (BPF_OP(insn->code)) { |
1401 | case BPF_JEQ: | |
1402 | jmp_cond = X86_JE; | |
1403 | break; | |
1404 | case BPF_JSET: | |
1405 | case BPF_JNE: | |
1406 | jmp_cond = X86_JNE; | |
1407 | break; | |
1408 | case BPF_JGT: | |
1409 | /* GT is unsigned '>', JA in x86 */ | |
1410 | jmp_cond = X86_JA; | |
1411 | break; | |
52afc51e DB |
1412 | case BPF_JLT: |
1413 | /* LT is unsigned '<', JB in x86 */ | |
1414 | jmp_cond = X86_JB; | |
1415 | break; | |
62258278 AS |
1416 | case BPF_JGE: |
1417 | /* GE is unsigned '>=', JAE in x86 */ | |
1418 | jmp_cond = X86_JAE; | |
1419 | break; | |
52afc51e DB |
1420 | case BPF_JLE: |
1421 | /* LE is unsigned '<=', JBE in x86 */ | |
1422 | jmp_cond = X86_JBE; | |
1423 | break; | |
62258278 | 1424 | case BPF_JSGT: |
a2c7a983 | 1425 | /* Signed '>', GT in x86 */ |
62258278 AS |
1426 | jmp_cond = X86_JG; |
1427 | break; | |
52afc51e | 1428 | case BPF_JSLT: |
a2c7a983 | 1429 | /* Signed '<', LT in x86 */ |
52afc51e DB |
1430 | jmp_cond = X86_JL; |
1431 | break; | |
62258278 | 1432 | case BPF_JSGE: |
a2c7a983 | 1433 | /* Signed '>=', GE in x86 */ |
62258278 AS |
1434 | jmp_cond = X86_JGE; |
1435 | break; | |
52afc51e | 1436 | case BPF_JSLE: |
a2c7a983 | 1437 | /* Signed '<=', LE in x86 */ |
52afc51e DB |
1438 | jmp_cond = X86_JLE; |
1439 | break; | |
a2c7a983 | 1440 | default: /* to silence GCC warning */ |
62258278 AS |
1441 | return -EFAULT; |
1442 | } | |
1443 | jmp_offset = addrs[i + insn->off] - addrs[i]; | |
1444 | if (is_imm8(jmp_offset)) { | |
1445 | EMIT2(jmp_cond, jmp_offset); | |
1446 | } else if (is_simm32(jmp_offset)) { | |
1447 | EMIT2_off32(0x0F, jmp_cond + 0x10, jmp_offset); | |
1448 | } else { | |
1449 | pr_err("cond_jmp gen bug %llx\n", jmp_offset); | |
1450 | return -EFAULT; | |
1451 | } | |
1452 | ||
1453 | break; | |
0a14842f | 1454 | |
62258278 | 1455 | case BPF_JMP | BPF_JA: |
1612a981 GB |
1456 | if (insn->off == -1) |
1457 | /* -1 jmp instructions will always jump | |
1458 | * backwards two bytes. Explicitly handling | |
1459 | * this case avoids wasting too many passes | |
1460 | * when there are long sequences of replaced | |
1461 | * dead code. | |
1462 | */ | |
1463 | jmp_offset = -2; | |
1464 | else | |
1465 | jmp_offset = addrs[i + insn->off] - addrs[i]; | |
1466 | ||
62258278 | 1467 | if (!jmp_offset) |
a2c7a983 | 1468 | /* Optimize out nop jumps */ |
62258278 AS |
1469 | break; |
1470 | emit_jmp: | |
1471 | if (is_imm8(jmp_offset)) { | |
1472 | EMIT2(0xEB, jmp_offset); | |
1473 | } else if (is_simm32(jmp_offset)) { | |
1474 | EMIT1_off32(0xE9, jmp_offset); | |
1475 | } else { | |
1476 | pr_err("jmp gen bug %llx\n", jmp_offset); | |
1477 | return -EFAULT; | |
1478 | } | |
1479 | break; | |
1480 | ||
62258278 | 1481 | case BPF_JMP | BPF_EXIT: |
769e0de6 | 1482 | if (seen_exit) { |
62258278 AS |
1483 | jmp_offset = ctx->cleanup_addr - addrs[i]; |
1484 | goto emit_jmp; | |
1485 | } | |
769e0de6 | 1486 | seen_exit = true; |
a2c7a983 | 1487 | /* Update cleanup_addr */ |
62258278 | 1488 | ctx->cleanup_addr = proglen; |
ebf7d1f5 | 1489 | pop_callee_regs(&prog, callee_regs_used); |
fe8d9571 AS |
1490 | EMIT1(0xC9); /* leave */ |
1491 | EMIT1(0xC3); /* ret */ | |
62258278 AS |
1492 | break; |
1493 | ||
f3c2af7b | 1494 | default: |
a2c7a983 IM |
1495 | /* |
1496 | * By design x86-64 JIT should support all BPF instructions. | |
62258278 | 1497 | * This error will be seen if new instruction was added |
a2c7a983 IM |
1498 | * to the interpreter, but not to the JIT, or if there is |
1499 | * junk in bpf_prog. | |
62258278 AS |
1500 | */ |
1501 | pr_err("bpf_jit: unknown opcode %02x\n", insn->code); | |
f3c2af7b AS |
1502 | return -EINVAL; |
1503 | } | |
62258278 | 1504 | |
f3c2af7b | 1505 | ilen = prog - temp; |
e0ee9c12 | 1506 | if (ilen > BPF_MAX_INSN_SIZE) { |
9383191d | 1507 | pr_err("bpf_jit: fatal insn size error\n"); |
e0ee9c12 AS |
1508 | return -EFAULT; |
1509 | } | |
1510 | ||
f3c2af7b AS |
1511 | if (image) { |
1512 | if (unlikely(proglen + ilen > oldproglen)) { | |
9383191d | 1513 | pr_err("bpf_jit: fatal error\n"); |
f3c2af7b | 1514 | return -EFAULT; |
0a14842f | 1515 | } |
f3c2af7b | 1516 | memcpy(image + proglen, temp, ilen); |
0a14842f | 1517 | } |
f3c2af7b AS |
1518 | proglen += ilen; |
1519 | addrs[i] = proglen; | |
1520 | prog = temp; | |
1521 | } | |
3dec541b AS |
1522 | |
1523 | if (image && excnt != bpf_prog->aux->num_exentries) { | |
1524 | pr_err("extable is not populated\n"); | |
1525 | return -EFAULT; | |
1526 | } | |
f3c2af7b AS |
1527 | return proglen; |
1528 | } | |
1529 | ||
85d33df3 | 1530 | static void save_regs(const struct btf_func_model *m, u8 **prog, int nr_args, |
fec56f58 AS |
1531 | int stack_size) |
1532 | { | |
1533 | int i; | |
1534 | /* Store function arguments to stack. | |
1535 | * For a function that accepts two pointers the sequence will be: | |
1536 | * mov QWORD PTR [rbp-0x10],rdi | |
1537 | * mov QWORD PTR [rbp-0x8],rsi | |
1538 | */ | |
1539 | for (i = 0; i < min(nr_args, 6); i++) | |
1540 | emit_stx(prog, bytes_to_bpf_size(m->arg_size[i]), | |
1541 | BPF_REG_FP, | |
1542 | i == 5 ? X86_REG_R9 : BPF_REG_1 + i, | |
1543 | -(stack_size - i * 8)); | |
1544 | } | |
1545 | ||
85d33df3 | 1546 | static void restore_regs(const struct btf_func_model *m, u8 **prog, int nr_args, |
fec56f58 AS |
1547 | int stack_size) |
1548 | { | |
1549 | int i; | |
1550 | ||
1551 | /* Restore function arguments from stack. | |
1552 | * For a function that accepts two pointers the sequence will be: | |
1553 | * EMIT4(0x48, 0x8B, 0x7D, 0xF0); mov rdi,QWORD PTR [rbp-0x10] | |
1554 | * EMIT4(0x48, 0x8B, 0x75, 0xF8); mov rsi,QWORD PTR [rbp-0x8] | |
1555 | */ | |
1556 | for (i = 0; i < min(nr_args, 6); i++) | |
1557 | emit_ldx(prog, bytes_to_bpf_size(m->arg_size[i]), | |
1558 | i == 5 ? X86_REG_R9 : BPF_REG_1 + i, | |
1559 | BPF_REG_FP, | |
1560 | -(stack_size - i * 8)); | |
1561 | } | |
1562 | ||
7e639208 | 1563 | static int invoke_bpf_prog(const struct btf_func_model *m, u8 **pprog, |
ae240823 | 1564 | struct bpf_prog *p, int stack_size, bool mod_ret) |
7e639208 KS |
1565 | { |
1566 | u8 *prog = *pprog; | |
1567 | int cnt = 0; | |
1568 | ||
1e6c62a8 AS |
1569 | if (p->aux->sleepable) { |
1570 | if (emit_call(&prog, __bpf_prog_enter_sleepable, prog)) | |
1571 | return -EINVAL; | |
1572 | } else { | |
1573 | if (emit_call(&prog, __bpf_prog_enter, prog)) | |
1574 | return -EINVAL; | |
1575 | /* remember prog start time returned by __bpf_prog_enter */ | |
1576 | emit_mov_reg(&prog, true, BPF_REG_6, BPF_REG_0); | |
1577 | } | |
7e639208 KS |
1578 | |
1579 | /* arg1: lea rdi, [rbp - stack_size] */ | |
1580 | EMIT4(0x48, 0x8D, 0x7D, -stack_size); | |
1581 | /* arg2: progs[i]->insnsi for interpreter */ | |
1582 | if (!p->jited) | |
1583 | emit_mov_imm64(&prog, BPF_REG_2, | |
1584 | (long) p->insnsi >> 32, | |
1585 | (u32) (long) p->insnsi); | |
1586 | /* call JITed bpf program or interpreter */ | |
1587 | if (emit_call(&prog, p->bpf_func, prog)) | |
1588 | return -EINVAL; | |
1589 | ||
ae240823 KS |
1590 | /* BPF_TRAMP_MODIFY_RETURN trampolines can modify the return |
1591 | * of the previous call which is then passed on the stack to | |
1592 | * the next BPF program. | |
1593 | */ | |
1594 | if (mod_ret) | |
1595 | emit_stx(&prog, BPF_DW, BPF_REG_FP, BPF_REG_0, -8); | |
1596 | ||
1e6c62a8 AS |
1597 | if (p->aux->sleepable) { |
1598 | if (emit_call(&prog, __bpf_prog_exit_sleepable, prog)) | |
1599 | return -EINVAL; | |
1600 | } else { | |
1601 | /* arg1: mov rdi, progs[i] */ | |
1602 | emit_mov_imm64(&prog, BPF_REG_1, (long) p >> 32, | |
1603 | (u32) (long) p); | |
1604 | /* arg2: mov rsi, rbx <- start time in nsec */ | |
1605 | emit_mov_reg(&prog, true, BPF_REG_2, BPF_REG_6); | |
1606 | if (emit_call(&prog, __bpf_prog_exit, prog)) | |
1607 | return -EINVAL; | |
1608 | } | |
7e639208 KS |
1609 | |
1610 | *pprog = prog; | |
1611 | return 0; | |
1612 | } | |
1613 | ||
1614 | static void emit_nops(u8 **pprog, unsigned int len) | |
1615 | { | |
1616 | unsigned int i, noplen; | |
1617 | u8 *prog = *pprog; | |
1618 | int cnt = 0; | |
1619 | ||
1620 | while (len > 0) { | |
1621 | noplen = len; | |
1622 | ||
1623 | if (noplen > ASM_NOP_MAX) | |
1624 | noplen = ASM_NOP_MAX; | |
1625 | ||
1626 | for (i = 0; i < noplen; i++) | |
1627 | EMIT1(ideal_nops[noplen][i]); | |
1628 | len -= noplen; | |
1629 | } | |
1630 | ||
1631 | *pprog = prog; | |
1632 | } | |
1633 | ||
1634 | static void emit_align(u8 **pprog, u32 align) | |
1635 | { | |
1636 | u8 *target, *prog = *pprog; | |
1637 | ||
1638 | target = PTR_ALIGN(prog, align); | |
1639 | if (target != prog) | |
1640 | emit_nops(&prog, target - prog); | |
1641 | ||
1642 | *pprog = prog; | |
1643 | } | |
1644 | ||
1645 | static int emit_cond_near_jump(u8 **pprog, void *func, void *ip, u8 jmp_cond) | |
1646 | { | |
1647 | u8 *prog = *pprog; | |
1648 | int cnt = 0; | |
1649 | s64 offset; | |
1650 | ||
1651 | offset = func - (ip + 2 + 4); | |
1652 | if (!is_simm32(offset)) { | |
1653 | pr_err("Target %p is out of range\n", func); | |
1654 | return -EINVAL; | |
1655 | } | |
1656 | EMIT2_off32(0x0F, jmp_cond + 0x10, offset); | |
1657 | *pprog = prog; | |
1658 | return 0; | |
1659 | } | |
1660 | ||
85d33df3 | 1661 | static int invoke_bpf(const struct btf_func_model *m, u8 **pprog, |
88fd9e53 | 1662 | struct bpf_tramp_progs *tp, int stack_size) |
fec56f58 | 1663 | { |
7e639208 | 1664 | int i; |
fec56f58 | 1665 | u8 *prog = *pprog; |
fec56f58 | 1666 | |
88fd9e53 | 1667 | for (i = 0; i < tp->nr_progs; i++) { |
ae240823 KS |
1668 | if (invoke_bpf_prog(m, &prog, tp->progs[i], stack_size, false)) |
1669 | return -EINVAL; | |
1670 | } | |
1671 | *pprog = prog; | |
1672 | return 0; | |
1673 | } | |
1674 | ||
1675 | static int invoke_bpf_mod_ret(const struct btf_func_model *m, u8 **pprog, | |
1676 | struct bpf_tramp_progs *tp, int stack_size, | |
1677 | u8 **branches) | |
1678 | { | |
1679 | u8 *prog = *pprog; | |
13fac1d8 | 1680 | int i, cnt = 0; |
ae240823 KS |
1681 | |
1682 | /* The first fmod_ret program will receive a garbage return value. | |
1683 | * Set this to 0 to avoid confusing the program. | |
1684 | */ | |
1685 | emit_mov_imm32(&prog, false, BPF_REG_0, 0); | |
1686 | emit_stx(&prog, BPF_DW, BPF_REG_FP, BPF_REG_0, -8); | |
1687 | for (i = 0; i < tp->nr_progs; i++) { | |
1688 | if (invoke_bpf_prog(m, &prog, tp->progs[i], stack_size, true)) | |
fec56f58 | 1689 | return -EINVAL; |
ae240823 | 1690 | |
13fac1d8 AS |
1691 | /* mod_ret prog stored return value into [rbp - 8]. Emit: |
1692 | * if (*(u64 *)(rbp - 8) != 0) | |
ae240823 | 1693 | * goto do_fexit; |
ae240823 | 1694 | */ |
13fac1d8 AS |
1695 | /* cmp QWORD PTR [rbp - 0x8], 0x0 */ |
1696 | EMIT4(0x48, 0x83, 0x7d, 0xf8); EMIT1(0x00); | |
ae240823 KS |
1697 | |
1698 | /* Save the location of the branch and Generate 6 nops | |
1699 | * (4 bytes for an offset and 2 bytes for the jump) These nops | |
1700 | * are replaced with a conditional jump once do_fexit (i.e. the | |
1701 | * start of the fexit invocation) is finalized. | |
1702 | */ | |
1703 | branches[i] = prog; | |
1704 | emit_nops(&prog, 4 + 2); | |
fec56f58 | 1705 | } |
ae240823 | 1706 | |
fec56f58 AS |
1707 | *pprog = prog; |
1708 | return 0; | |
1709 | } | |
1710 | ||
1711 | /* Example: | |
1712 | * __be16 eth_type_trans(struct sk_buff *skb, struct net_device *dev); | |
1713 | * its 'struct btf_func_model' will be nr_args=2 | |
1714 | * The assembly code when eth_type_trans is executing after trampoline: | |
1715 | * | |
1716 | * push rbp | |
1717 | * mov rbp, rsp | |
1718 | * sub rsp, 16 // space for skb and dev | |
1719 | * push rbx // temp regs to pass start time | |
1720 | * mov qword ptr [rbp - 16], rdi // save skb pointer to stack | |
1721 | * mov qword ptr [rbp - 8], rsi // save dev pointer to stack | |
1722 | * call __bpf_prog_enter // rcu_read_lock and preempt_disable | |
1723 | * mov rbx, rax // remember start time in bpf stats are enabled | |
1724 | * lea rdi, [rbp - 16] // R1==ctx of bpf prog | |
1725 | * call addr_of_jited_FENTRY_prog | |
1726 | * movabsq rdi, 64bit_addr_of_struct_bpf_prog // unused if bpf stats are off | |
1727 | * mov rsi, rbx // prog start time | |
1728 | * call __bpf_prog_exit // rcu_read_unlock, preempt_enable and stats math | |
1729 | * mov rdi, qword ptr [rbp - 16] // restore skb pointer from stack | |
1730 | * mov rsi, qword ptr [rbp - 8] // restore dev pointer from stack | |
1731 | * pop rbx | |
1732 | * leave | |
1733 | * ret | |
1734 | * | |
1735 | * eth_type_trans has 5 byte nop at the beginning. These 5 bytes will be | |
1736 | * replaced with 'call generated_bpf_trampoline'. When it returns | |
1737 | * eth_type_trans will continue executing with original skb and dev pointers. | |
1738 | * | |
1739 | * The assembly code when eth_type_trans is called from trampoline: | |
1740 | * | |
1741 | * push rbp | |
1742 | * mov rbp, rsp | |
1743 | * sub rsp, 24 // space for skb, dev, return value | |
1744 | * push rbx // temp regs to pass start time | |
1745 | * mov qword ptr [rbp - 24], rdi // save skb pointer to stack | |
1746 | * mov qword ptr [rbp - 16], rsi // save dev pointer to stack | |
1747 | * call __bpf_prog_enter // rcu_read_lock and preempt_disable | |
1748 | * mov rbx, rax // remember start time if bpf stats are enabled | |
1749 | * lea rdi, [rbp - 24] // R1==ctx of bpf prog | |
1750 | * call addr_of_jited_FENTRY_prog // bpf prog can access skb and dev | |
1751 | * movabsq rdi, 64bit_addr_of_struct_bpf_prog // unused if bpf stats are off | |
1752 | * mov rsi, rbx // prog start time | |
1753 | * call __bpf_prog_exit // rcu_read_unlock, preempt_enable and stats math | |
1754 | * mov rdi, qword ptr [rbp - 24] // restore skb pointer from stack | |
1755 | * mov rsi, qword ptr [rbp - 16] // restore dev pointer from stack | |
1756 | * call eth_type_trans+5 // execute body of eth_type_trans | |
1757 | * mov qword ptr [rbp - 8], rax // save return value | |
1758 | * call __bpf_prog_enter // rcu_read_lock and preempt_disable | |
1759 | * mov rbx, rax // remember start time in bpf stats are enabled | |
1760 | * lea rdi, [rbp - 24] // R1==ctx of bpf prog | |
1761 | * call addr_of_jited_FEXIT_prog // bpf prog can access skb, dev, return value | |
1762 | * movabsq rdi, 64bit_addr_of_struct_bpf_prog // unused if bpf stats are off | |
1763 | * mov rsi, rbx // prog start time | |
1764 | * call __bpf_prog_exit // rcu_read_unlock, preempt_enable and stats math | |
1765 | * mov rax, qword ptr [rbp - 8] // restore eth_type_trans's return value | |
1766 | * pop rbx | |
1767 | * leave | |
1768 | * add rsp, 8 // skip eth_type_trans's frame | |
1769 | * ret // return to its caller | |
1770 | */ | |
85d33df3 MKL |
1771 | int arch_prepare_bpf_trampoline(void *image, void *image_end, |
1772 | const struct btf_func_model *m, u32 flags, | |
88fd9e53 | 1773 | struct bpf_tramp_progs *tprogs, |
fec56f58 AS |
1774 | void *orig_call) |
1775 | { | |
ae240823 | 1776 | int ret, i, cnt = 0, nr_args = m->nr_args; |
fec56f58 | 1777 | int stack_size = nr_args * 8; |
88fd9e53 KS |
1778 | struct bpf_tramp_progs *fentry = &tprogs[BPF_TRAMP_FENTRY]; |
1779 | struct bpf_tramp_progs *fexit = &tprogs[BPF_TRAMP_FEXIT]; | |
ae240823 KS |
1780 | struct bpf_tramp_progs *fmod_ret = &tprogs[BPF_TRAMP_MODIFY_RETURN]; |
1781 | u8 **branches = NULL; | |
fec56f58 AS |
1782 | u8 *prog; |
1783 | ||
1784 | /* x86-64 supports up to 6 arguments. 7+ can be added in the future */ | |
1785 | if (nr_args > 6) | |
1786 | return -ENOTSUPP; | |
1787 | ||
1788 | if ((flags & BPF_TRAMP_F_RESTORE_REGS) && | |
1789 | (flags & BPF_TRAMP_F_SKIP_FRAME)) | |
1790 | return -EINVAL; | |
1791 | ||
1792 | if (flags & BPF_TRAMP_F_CALL_ORIG) | |
1793 | stack_size += 8; /* room for return value of orig_call */ | |
1794 | ||
1795 | if (flags & BPF_TRAMP_F_SKIP_FRAME) | |
1796 | /* skip patched call instruction and point orig_call to actual | |
1797 | * body of the kernel function. | |
1798 | */ | |
4b3da77b | 1799 | orig_call += X86_PATCH_SIZE; |
fec56f58 AS |
1800 | |
1801 | prog = image; | |
1802 | ||
1803 | EMIT1(0x55); /* push rbp */ | |
1804 | EMIT3(0x48, 0x89, 0xE5); /* mov rbp, rsp */ | |
1805 | EMIT4(0x48, 0x83, 0xEC, stack_size); /* sub rsp, stack_size */ | |
1806 | EMIT1(0x53); /* push rbx */ | |
1807 | ||
1808 | save_regs(m, &prog, nr_args, stack_size); | |
1809 | ||
88fd9e53 KS |
1810 | if (fentry->nr_progs) |
1811 | if (invoke_bpf(m, &prog, fentry, stack_size)) | |
fec56f58 AS |
1812 | return -EINVAL; |
1813 | ||
ae240823 KS |
1814 | if (fmod_ret->nr_progs) { |
1815 | branches = kcalloc(fmod_ret->nr_progs, sizeof(u8 *), | |
1816 | GFP_KERNEL); | |
1817 | if (!branches) | |
1818 | return -ENOMEM; | |
1819 | ||
1820 | if (invoke_bpf_mod_ret(m, &prog, fmod_ret, stack_size, | |
1821 | branches)) { | |
1822 | ret = -EINVAL; | |
1823 | goto cleanup; | |
1824 | } | |
1825 | } | |
1826 | ||
fec56f58 | 1827 | if (flags & BPF_TRAMP_F_CALL_ORIG) { |
ae240823 | 1828 | if (fentry->nr_progs || fmod_ret->nr_progs) |
fec56f58 AS |
1829 | restore_regs(m, &prog, nr_args, stack_size); |
1830 | ||
1831 | /* call original function */ | |
ae240823 KS |
1832 | if (emit_call(&prog, orig_call, prog)) { |
1833 | ret = -EINVAL; | |
1834 | goto cleanup; | |
1835 | } | |
fec56f58 AS |
1836 | /* remember return value in a stack for bpf prog to access */ |
1837 | emit_stx(&prog, BPF_DW, BPF_REG_FP, BPF_REG_0, -8); | |
1838 | } | |
1839 | ||
ae240823 KS |
1840 | if (fmod_ret->nr_progs) { |
1841 | /* From Intel 64 and IA-32 Architectures Optimization | |
1842 | * Reference Manual, 3.4.1.4 Code Alignment, Assembly/Compiler | |
1843 | * Coding Rule 11: All branch targets should be 16-byte | |
1844 | * aligned. | |
1845 | */ | |
1846 | emit_align(&prog, 16); | |
1847 | /* Update the branches saved in invoke_bpf_mod_ret with the | |
1848 | * aligned address of do_fexit. | |
1849 | */ | |
1850 | for (i = 0; i < fmod_ret->nr_progs; i++) | |
1851 | emit_cond_near_jump(&branches[i], prog, branches[i], | |
1852 | X86_JNE); | |
1853 | } | |
1854 | ||
88fd9e53 | 1855 | if (fexit->nr_progs) |
ae240823 KS |
1856 | if (invoke_bpf(m, &prog, fexit, stack_size)) { |
1857 | ret = -EINVAL; | |
1858 | goto cleanup; | |
1859 | } | |
fec56f58 AS |
1860 | |
1861 | if (flags & BPF_TRAMP_F_RESTORE_REGS) | |
1862 | restore_regs(m, &prog, nr_args, stack_size); | |
1863 | ||
ae240823 KS |
1864 | /* This needs to be done regardless. If there were fmod_ret programs, |
1865 | * the return value is only updated on the stack and still needs to be | |
1866 | * restored to R0. | |
1867 | */ | |
fec56f58 AS |
1868 | if (flags & BPF_TRAMP_F_CALL_ORIG) |
1869 | /* restore original return value back into RAX */ | |
1870 | emit_ldx(&prog, BPF_DW, BPF_REG_0, BPF_REG_FP, -8); | |
1871 | ||
1872 | EMIT1(0x5B); /* pop rbx */ | |
1873 | EMIT1(0xC9); /* leave */ | |
1874 | if (flags & BPF_TRAMP_F_SKIP_FRAME) | |
1875 | /* skip our return address and return to parent */ | |
1876 | EMIT4(0x48, 0x83, 0xC4, 8); /* add rsp, 8 */ | |
1877 | EMIT1(0xC3); /* ret */ | |
85d33df3 | 1878 | /* Make sure the trampoline generation logic doesn't overflow */ |
ae240823 KS |
1879 | if (WARN_ON_ONCE(prog > (u8 *)image_end - BPF_INSN_SAFETY)) { |
1880 | ret = -EFAULT; | |
1881 | goto cleanup; | |
1882 | } | |
1883 | ret = prog - (u8 *)image; | |
1884 | ||
1885 | cleanup: | |
1886 | kfree(branches); | |
1887 | return ret; | |
fec56f58 AS |
1888 | } |
1889 | ||
75ccbef6 BT |
1890 | static int emit_fallback_jump(u8 **pprog) |
1891 | { | |
1892 | u8 *prog = *pprog; | |
1893 | int err = 0; | |
1894 | ||
1895 | #ifdef CONFIG_RETPOLINE | |
1896 | /* Note that this assumes the the compiler uses external | |
1897 | * thunks for indirect calls. Both clang and GCC use the same | |
1898 | * naming convention for external thunks. | |
1899 | */ | |
1900 | err = emit_jump(&prog, __x86_indirect_thunk_rdx, prog); | |
1901 | #else | |
1902 | int cnt = 0; | |
1903 | ||
1904 | EMIT2(0xFF, 0xE2); /* jmp rdx */ | |
1905 | #endif | |
1906 | *pprog = prog; | |
1907 | return err; | |
1908 | } | |
1909 | ||
1910 | static int emit_bpf_dispatcher(u8 **pprog, int a, int b, s64 *progs) | |
1911 | { | |
7e639208 | 1912 | u8 *jg_reloc, *prog = *pprog; |
75ccbef6 | 1913 | int pivot, err, jg_bytes = 1, cnt = 0; |
75ccbef6 BT |
1914 | s64 jg_offset; |
1915 | ||
1916 | if (a == b) { | |
1917 | /* Leaf node of recursion, i.e. not a range of indices | |
1918 | * anymore. | |
1919 | */ | |
1920 | EMIT1(add_1mod(0x48, BPF_REG_3)); /* cmp rdx,func */ | |
1921 | if (!is_simm32(progs[a])) | |
1922 | return -1; | |
1923 | EMIT2_off32(0x81, add_1reg(0xF8, BPF_REG_3), | |
1924 | progs[a]); | |
1925 | err = emit_cond_near_jump(&prog, /* je func */ | |
1926 | (void *)progs[a], prog, | |
1927 | X86_JE); | |
1928 | if (err) | |
1929 | return err; | |
1930 | ||
1931 | err = emit_fallback_jump(&prog); /* jmp thunk/indirect */ | |
1932 | if (err) | |
1933 | return err; | |
1934 | ||
1935 | *pprog = prog; | |
1936 | return 0; | |
1937 | } | |
1938 | ||
1939 | /* Not a leaf node, so we pivot, and recursively descend into | |
1940 | * the lower and upper ranges. | |
1941 | */ | |
1942 | pivot = (b - a) / 2; | |
1943 | EMIT1(add_1mod(0x48, BPF_REG_3)); /* cmp rdx,func */ | |
1944 | if (!is_simm32(progs[a + pivot])) | |
1945 | return -1; | |
1946 | EMIT2_off32(0x81, add_1reg(0xF8, BPF_REG_3), progs[a + pivot]); | |
1947 | ||
1948 | if (pivot > 2) { /* jg upper_part */ | |
1949 | /* Require near jump. */ | |
1950 | jg_bytes = 4; | |
1951 | EMIT2_off32(0x0F, X86_JG + 0x10, 0); | |
1952 | } else { | |
1953 | EMIT2(X86_JG, 0); | |
1954 | } | |
1955 | jg_reloc = prog; | |
1956 | ||
1957 | err = emit_bpf_dispatcher(&prog, a, a + pivot, /* emit lower_part */ | |
1958 | progs); | |
1959 | if (err) | |
1960 | return err; | |
1961 | ||
116eb788 BT |
1962 | /* From Intel 64 and IA-32 Architectures Optimization |
1963 | * Reference Manual, 3.4.1.4 Code Alignment, Assembly/Compiler | |
1964 | * Coding Rule 11: All branch targets should be 16-byte | |
1965 | * aligned. | |
1966 | */ | |
7e639208 | 1967 | emit_align(&prog, 16); |
75ccbef6 BT |
1968 | jg_offset = prog - jg_reloc; |
1969 | emit_code(jg_reloc - jg_bytes, jg_offset, jg_bytes); | |
1970 | ||
1971 | err = emit_bpf_dispatcher(&prog, a + pivot + 1, /* emit upper_part */ | |
1972 | b, progs); | |
1973 | if (err) | |
1974 | return err; | |
1975 | ||
1976 | *pprog = prog; | |
1977 | return 0; | |
1978 | } | |
1979 | ||
1980 | static int cmp_ips(const void *a, const void *b) | |
1981 | { | |
1982 | const s64 *ipa = a; | |
1983 | const s64 *ipb = b; | |
1984 | ||
1985 | if (*ipa > *ipb) | |
1986 | return 1; | |
1987 | if (*ipa < *ipb) | |
1988 | return -1; | |
1989 | return 0; | |
1990 | } | |
1991 | ||
1992 | int arch_prepare_bpf_dispatcher(void *image, s64 *funcs, int num_funcs) | |
1993 | { | |
1994 | u8 *prog = image; | |
1995 | ||
1996 | sort(funcs, num_funcs, sizeof(funcs[0]), cmp_ips, NULL); | |
1997 | return emit_bpf_dispatcher(&prog, 0, num_funcs - 1, funcs); | |
1998 | } | |
1999 | ||
1c2a088a AS |
2000 | struct x64_jit_data { |
2001 | struct bpf_binary_header *header; | |
2002 | int *addrs; | |
2003 | u8 *image; | |
2004 | int proglen; | |
2005 | struct jit_context ctx; | |
2006 | }; | |
2007 | ||
d1c55ab5 | 2008 | struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog) |
f3c2af7b AS |
2009 | { |
2010 | struct bpf_binary_header *header = NULL; | |
959a7579 | 2011 | struct bpf_prog *tmp, *orig_prog = prog; |
1c2a088a | 2012 | struct x64_jit_data *jit_data; |
f3c2af7b AS |
2013 | int proglen, oldproglen = 0; |
2014 | struct jit_context ctx = {}; | |
959a7579 | 2015 | bool tmp_blinded = false; |
1c2a088a | 2016 | bool extra_pass = false; |
f3c2af7b AS |
2017 | u8 *image = NULL; |
2018 | int *addrs; | |
2019 | int pass; | |
2020 | int i; | |
2021 | ||
60b58afc | 2022 | if (!prog->jit_requested) |
959a7579 DB |
2023 | return orig_prog; |
2024 | ||
2025 | tmp = bpf_jit_blind_constants(prog); | |
a2c7a983 IM |
2026 | /* |
2027 | * If blinding was requested and we failed during blinding, | |
959a7579 DB |
2028 | * we must fall back to the interpreter. |
2029 | */ | |
2030 | if (IS_ERR(tmp)) | |
2031 | return orig_prog; | |
2032 | if (tmp != prog) { | |
2033 | tmp_blinded = true; | |
2034 | prog = tmp; | |
2035 | } | |
0a14842f | 2036 | |
1c2a088a AS |
2037 | jit_data = prog->aux->jit_data; |
2038 | if (!jit_data) { | |
2039 | jit_data = kzalloc(sizeof(*jit_data), GFP_KERNEL); | |
2040 | if (!jit_data) { | |
2041 | prog = orig_prog; | |
2042 | goto out; | |
2043 | } | |
2044 | prog->aux->jit_data = jit_data; | |
2045 | } | |
2046 | addrs = jit_data->addrs; | |
2047 | if (addrs) { | |
2048 | ctx = jit_data->ctx; | |
2049 | oldproglen = jit_data->proglen; | |
2050 | image = jit_data->image; | |
2051 | header = jit_data->header; | |
2052 | extra_pass = true; | |
2053 | goto skip_init_addrs; | |
2054 | } | |
7c2e988f | 2055 | addrs = kmalloc_array(prog->len + 1, sizeof(*addrs), GFP_KERNEL); |
959a7579 DB |
2056 | if (!addrs) { |
2057 | prog = orig_prog; | |
1c2a088a | 2058 | goto out_addrs; |
959a7579 | 2059 | } |
f3c2af7b | 2060 | |
a2c7a983 IM |
2061 | /* |
2062 | * Before first pass, make a rough estimation of addrs[] | |
2063 | * each BPF instruction is translated to less than 64 bytes | |
f3c2af7b | 2064 | */ |
7c2e988f | 2065 | for (proglen = 0, i = 0; i <= prog->len; i++) { |
f3c2af7b AS |
2066 | proglen += 64; |
2067 | addrs[i] = proglen; | |
2068 | } | |
2069 | ctx.cleanup_addr = proglen; | |
1c2a088a | 2070 | skip_init_addrs: |
f3c2af7b | 2071 | |
a2c7a983 IM |
2072 | /* |
2073 | * JITed image shrinks with every pass and the loop iterates | |
2074 | * until the image stops shrinking. Very large BPF programs | |
3f7352bf | 2075 | * may converge on the last pass. In such case do one more |
a2c7a983 | 2076 | * pass to emit the final image. |
3f7352bf | 2077 | */ |
6007b080 | 2078 | for (pass = 0; pass < 20 || image; pass++) { |
f3c2af7b AS |
2079 | proglen = do_jit(prog, addrs, image, oldproglen, &ctx); |
2080 | if (proglen <= 0) { | |
3aab8884 | 2081 | out_image: |
f3c2af7b AS |
2082 | image = NULL; |
2083 | if (header) | |
738cbe72 | 2084 | bpf_jit_binary_free(header); |
959a7579 DB |
2085 | prog = orig_prog; |
2086 | goto out_addrs; | |
f3c2af7b | 2087 | } |
0a14842f | 2088 | if (image) { |
e0ee9c12 | 2089 | if (proglen != oldproglen) { |
f3c2af7b AS |
2090 | pr_err("bpf_jit: proglen=%d != oldproglen=%d\n", |
2091 | proglen, oldproglen); | |
3aab8884 | 2092 | goto out_image; |
e0ee9c12 | 2093 | } |
0a14842f ED |
2094 | break; |
2095 | } | |
2096 | if (proglen == oldproglen) { | |
3dec541b AS |
2097 | /* |
2098 | * The number of entries in extable is the number of BPF_LDX | |
2099 | * insns that access kernel memory via "pointer to BTF type". | |
2100 | * The verifier changed their opcode from LDX|MEM|size | |
2101 | * to LDX|PROBE_MEM|size to make JITing easier. | |
2102 | */ | |
2103 | u32 align = __alignof__(struct exception_table_entry); | |
2104 | u32 extable_size = prog->aux->num_exentries * | |
2105 | sizeof(struct exception_table_entry); | |
2106 | ||
2107 | /* allocate module memory for x86 insns and extable */ | |
2108 | header = bpf_jit_binary_alloc(roundup(proglen, align) + extable_size, | |
2109 | &image, align, jit_fill_hole); | |
959a7579 DB |
2110 | if (!header) { |
2111 | prog = orig_prog; | |
2112 | goto out_addrs; | |
2113 | } | |
3dec541b | 2114 | prog->aux->extable = (void *) image + roundup(proglen, align); |
0a14842f ED |
2115 | } |
2116 | oldproglen = proglen; | |
6007b080 | 2117 | cond_resched(); |
0a14842f | 2118 | } |
79617801 | 2119 | |
0a14842f | 2120 | if (bpf_jit_enable > 1) |
485d6511 | 2121 | bpf_jit_dump(prog->len, proglen, pass + 1, image); |
0a14842f ED |
2122 | |
2123 | if (image) { | |
1c2a088a | 2124 | if (!prog->is_func || extra_pass) { |
428d5df1 | 2125 | bpf_tail_call_direct_fixup(prog); |
1c2a088a AS |
2126 | bpf_jit_binary_lock_ro(header); |
2127 | } else { | |
2128 | jit_data->addrs = addrs; | |
2129 | jit_data->ctx = ctx; | |
2130 | jit_data->proglen = proglen; | |
2131 | jit_data->image = image; | |
2132 | jit_data->header = header; | |
2133 | } | |
f3c2af7b | 2134 | prog->bpf_func = (void *)image; |
a91263d5 | 2135 | prog->jited = 1; |
783d28dd | 2136 | prog->jited_len = proglen; |
9d5ecb09 DB |
2137 | } else { |
2138 | prog = orig_prog; | |
0a14842f | 2139 | } |
959a7579 | 2140 | |
39f56ca9 | 2141 | if (!image || !prog->is_func || extra_pass) { |
c454a46b | 2142 | if (image) |
7c2e988f | 2143 | bpf_prog_fill_jited_linfo(prog, addrs + 1); |
959a7579 | 2144 | out_addrs: |
1c2a088a AS |
2145 | kfree(addrs); |
2146 | kfree(jit_data); | |
2147 | prog->aux->jit_data = NULL; | |
2148 | } | |
959a7579 DB |
2149 | out: |
2150 | if (tmp_blinded) | |
2151 | bpf_jit_prog_release_other(prog, prog == orig_prog ? | |
2152 | tmp : orig_prog); | |
d1c55ab5 | 2153 | return prog; |
0a14842f | 2154 | } |