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156d0e29 NR |
1 | /* |
2 | * bpf_jit_comp64.c: eBPF JIT compiler | |
3 | * | |
4 | * Copyright 2016 Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> | |
5 | * IBM Corporation | |
6 | * | |
7 | * Based on the powerpc classic BPF JIT compiler by Matt Evans | |
8 | * | |
9 | * This program is free software; you can redistribute it and/or | |
10 | * modify it under the terms of the GNU General Public License | |
11 | * as published by the Free Software Foundation; version 2 | |
12 | * of the License. | |
13 | */ | |
14 | #include <linux/moduleloader.h> | |
15 | #include <asm/cacheflush.h> | |
16 | #include <linux/netdevice.h> | |
17 | #include <linux/filter.h> | |
18 | #include <linux/if_vlan.h> | |
19 | #include <asm/kprobes.h> | |
ce076141 | 20 | #include <linux/bpf.h> |
156d0e29 NR |
21 | |
22 | #include "bpf_jit64.h" | |
23 | ||
24 | int bpf_jit_enable __read_mostly; | |
25 | ||
26 | static void bpf_jit_fill_ill_insns(void *area, unsigned int size) | |
27 | { | |
28 | int *p = area; | |
29 | ||
30 | /* Fill whole space with trap instructions */ | |
31 | while (p < (int *)((char *)area + size)) | |
32 | *p++ = BREAKPOINT_INSTRUCTION; | |
33 | } | |
34 | ||
35 | static inline void bpf_flush_icache(void *start, void *end) | |
36 | { | |
37 | smp_wmb(); | |
38 | flush_icache_range((unsigned long)start, (unsigned long)end); | |
39 | } | |
40 | ||
41 | static inline bool bpf_is_seen_register(struct codegen_context *ctx, int i) | |
42 | { | |
43 | return (ctx->seen & (1 << (31 - b2p[i]))); | |
44 | } | |
45 | ||
46 | static inline void bpf_set_seen_register(struct codegen_context *ctx, int i) | |
47 | { | |
48 | ctx->seen |= (1 << (31 - b2p[i])); | |
49 | } | |
50 | ||
51 | static inline bool bpf_has_stack_frame(struct codegen_context *ctx) | |
52 | { | |
53 | /* | |
54 | * We only need a stack frame if: | |
55 | * - we call other functions (kernel helpers), or | |
56 | * - the bpf program uses its stack area | |
57 | * The latter condition is deduced from the usage of BPF_REG_FP | |
58 | */ | |
59 | return ctx->seen & SEEN_FUNC || bpf_is_seen_register(ctx, BPF_REG_FP); | |
60 | } | |
61 | ||
7b847f52 NR |
62 | /* |
63 | * When not setting up our own stackframe, the redzone usage is: | |
64 | * | |
65 | * [ prev sp ] <------------- | |
66 | * [ ... ] | | |
67 | * sp (r1) ---> [ stack pointer ] -------------- | |
68 | * [ nv gpr save area ] 8*8 | |
69 | * [ tail_call_cnt ] 8 | |
70 | * [ local_tmp_var ] 8 | |
71 | * [ unused red zone ] 208 bytes protected | |
72 | */ | |
73 | static int bpf_jit_stack_local(struct codegen_context *ctx) | |
74 | { | |
75 | if (bpf_has_stack_frame(ctx)) | |
76 | return STACK_FRAME_MIN_SIZE + MAX_BPF_STACK; | |
77 | else | |
78 | return -(BPF_PPC_STACK_SAVE + 16); | |
79 | } | |
80 | ||
ce076141 NR |
81 | static int bpf_jit_stack_tailcallcnt(struct codegen_context *ctx) |
82 | { | |
83 | return bpf_jit_stack_local(ctx) + 8; | |
84 | } | |
85 | ||
7b847f52 NR |
86 | static int bpf_jit_stack_offsetof(struct codegen_context *ctx, int reg) |
87 | { | |
88 | if (reg >= BPF_PPC_NVR_MIN && reg < 32) | |
89 | return (bpf_has_stack_frame(ctx) ? BPF_PPC_STACKFRAME : 0) | |
90 | - (8 * (32 - reg)); | |
91 | ||
92 | pr_err("BPF JIT is asking about unknown registers"); | |
93 | BUG(); | |
94 | } | |
95 | ||
156d0e29 NR |
96 | static void bpf_jit_emit_skb_loads(u32 *image, struct codegen_context *ctx) |
97 | { | |
98 | /* | |
99 | * Load skb->len and skb->data_len | |
100 | * r3 points to skb | |
101 | */ | |
102 | PPC_LWZ(b2p[SKB_HLEN_REG], 3, offsetof(struct sk_buff, len)); | |
103 | PPC_LWZ(b2p[TMP_REG_1], 3, offsetof(struct sk_buff, data_len)); | |
104 | /* header_len = len - data_len */ | |
105 | PPC_SUB(b2p[SKB_HLEN_REG], b2p[SKB_HLEN_REG], b2p[TMP_REG_1]); | |
106 | ||
107 | /* skb->data pointer */ | |
108 | PPC_BPF_LL(b2p[SKB_DATA_REG], 3, offsetof(struct sk_buff, data)); | |
109 | } | |
110 | ||
ce076141 | 111 | static void bpf_jit_build_prologue(u32 *image, struct codegen_context *ctx) |
156d0e29 | 112 | { |
ce076141 NR |
113 | int i; |
114 | ||
156d0e29 | 115 | /* |
ce076141 NR |
116 | * Initialize tail_call_cnt if we do tail calls. |
117 | * Otherwise, put in NOPs so that it can be skipped when we are | |
118 | * invoked through a tail call. | |
156d0e29 | 119 | */ |
ce076141 NR |
120 | if (ctx->seen & SEEN_TAILCALL) { |
121 | PPC_LI(b2p[TMP_REG_1], 0); | |
122 | /* this goes in the redzone */ | |
123 | PPC_BPF_STL(b2p[TMP_REG_1], 1, -(BPF_PPC_STACK_SAVE + 8)); | |
124 | } else { | |
125 | PPC_NOP(); | |
126 | PPC_NOP(); | |
127 | } | |
156d0e29 | 128 | |
ce076141 | 129 | #define BPF_TAILCALL_PROLOGUE_SIZE 8 |
156d0e29 | 130 | |
7b847f52 | 131 | if (bpf_has_stack_frame(ctx)) { |
156d0e29 NR |
132 | /* |
133 | * We need a stack frame, but we don't necessarily need to | |
134 | * save/restore LR unless we call other functions | |
135 | */ | |
136 | if (ctx->seen & SEEN_FUNC) { | |
137 | EMIT(PPC_INST_MFLR | __PPC_RT(R0)); | |
138 | PPC_BPF_STL(0, 1, PPC_LR_STKOFF); | |
139 | } | |
140 | ||
141 | PPC_BPF_STLU(1, 1, -BPF_PPC_STACKFRAME); | |
142 | } | |
143 | ||
144 | /* | |
145 | * Back up non-volatile regs -- BPF registers 6-10 | |
146 | * If we haven't created our own stack frame, we save these | |
147 | * in the protected zone below the previous stack frame | |
148 | */ | |
149 | for (i = BPF_REG_6; i <= BPF_REG_10; i++) | |
150 | if (bpf_is_seen_register(ctx, i)) | |
7b847f52 | 151 | PPC_BPF_STL(b2p[i], 1, bpf_jit_stack_offsetof(ctx, b2p[i])); |
156d0e29 NR |
152 | |
153 | /* | |
154 | * Save additional non-volatile regs if we cache skb | |
155 | * Also, setup skb data | |
156 | */ | |
157 | if (ctx->seen & SEEN_SKB) { | |
158 | PPC_BPF_STL(b2p[SKB_HLEN_REG], 1, | |
7b847f52 | 159 | bpf_jit_stack_offsetof(ctx, b2p[SKB_HLEN_REG])); |
156d0e29 | 160 | PPC_BPF_STL(b2p[SKB_DATA_REG], 1, |
7b847f52 | 161 | bpf_jit_stack_offsetof(ctx, b2p[SKB_DATA_REG])); |
156d0e29 NR |
162 | bpf_jit_emit_skb_loads(image, ctx); |
163 | } | |
164 | ||
165 | /* Setup frame pointer to point to the bpf stack area */ | |
166 | if (bpf_is_seen_register(ctx, BPF_REG_FP)) | |
167 | PPC_ADDI(b2p[BPF_REG_FP], 1, | |
7b847f52 | 168 | STACK_FRAME_MIN_SIZE + MAX_BPF_STACK); |
156d0e29 NR |
169 | } |
170 | ||
ce076141 | 171 | static void bpf_jit_emit_common_epilogue(u32 *image, struct codegen_context *ctx) |
156d0e29 NR |
172 | { |
173 | int i; | |
156d0e29 | 174 | |
156d0e29 NR |
175 | /* Restore NVRs */ |
176 | for (i = BPF_REG_6; i <= BPF_REG_10; i++) | |
177 | if (bpf_is_seen_register(ctx, i)) | |
7b847f52 | 178 | PPC_BPF_LL(b2p[i], 1, bpf_jit_stack_offsetof(ctx, b2p[i])); |
156d0e29 NR |
179 | |
180 | /* Restore non-volatile registers used for skb cache */ | |
181 | if (ctx->seen & SEEN_SKB) { | |
182 | PPC_BPF_LL(b2p[SKB_HLEN_REG], 1, | |
7b847f52 | 183 | bpf_jit_stack_offsetof(ctx, b2p[SKB_HLEN_REG])); |
156d0e29 | 184 | PPC_BPF_LL(b2p[SKB_DATA_REG], 1, |
7b847f52 | 185 | bpf_jit_stack_offsetof(ctx, b2p[SKB_DATA_REG])); |
156d0e29 NR |
186 | } |
187 | ||
188 | /* Tear down our stack frame */ | |
7b847f52 | 189 | if (bpf_has_stack_frame(ctx)) { |
156d0e29 NR |
190 | PPC_ADDI(1, 1, BPF_PPC_STACKFRAME); |
191 | if (ctx->seen & SEEN_FUNC) { | |
192 | PPC_BPF_LL(0, 1, PPC_LR_STKOFF); | |
193 | PPC_MTLR(0); | |
194 | } | |
195 | } | |
ce076141 NR |
196 | } |
197 | ||
198 | static void bpf_jit_build_epilogue(u32 *image, struct codegen_context *ctx) | |
199 | { | |
200 | bpf_jit_emit_common_epilogue(image, ctx); | |
201 | ||
202 | /* Move result to r3 */ | |
203 | PPC_MR(3, b2p[BPF_REG_0]); | |
156d0e29 NR |
204 | |
205 | PPC_BLR(); | |
206 | } | |
207 | ||
ce076141 NR |
208 | static void bpf_jit_emit_func_call(u32 *image, struct codegen_context *ctx, u64 func) |
209 | { | |
210 | #ifdef PPC64_ELF_ABI_v1 | |
211 | /* func points to the function descriptor */ | |
212 | PPC_LI64(b2p[TMP_REG_2], func); | |
213 | /* Load actual entry point from function descriptor */ | |
214 | PPC_BPF_LL(b2p[TMP_REG_1], b2p[TMP_REG_2], 0); | |
215 | /* ... and move it to LR */ | |
216 | PPC_MTLR(b2p[TMP_REG_1]); | |
217 | /* | |
218 | * Load TOC from function descriptor at offset 8. | |
219 | * We can clobber r2 since we get called through a | |
220 | * function pointer (so caller will save/restore r2) | |
221 | * and since we don't use a TOC ourself. | |
222 | */ | |
223 | PPC_BPF_LL(2, b2p[TMP_REG_2], 8); | |
224 | #else | |
225 | /* We can clobber r12 */ | |
226 | PPC_FUNC_ADDR(12, func); | |
227 | PPC_MTLR(12); | |
228 | #endif | |
229 | PPC_BLRL(); | |
230 | } | |
231 | ||
232 | static void bpf_jit_emit_tail_call(u32 *image, struct codegen_context *ctx, u32 out) | |
233 | { | |
234 | /* | |
235 | * By now, the eBPF program has already setup parameters in r3, r4 and r5 | |
236 | * r3/BPF_REG_1 - pointer to ctx -- passed as is to the next bpf program | |
237 | * r4/BPF_REG_2 - pointer to bpf_array | |
238 | * r5/BPF_REG_3 - index in bpf_array | |
239 | */ | |
240 | int b2p_bpf_array = b2p[BPF_REG_2]; | |
241 | int b2p_index = b2p[BPF_REG_3]; | |
242 | ||
243 | /* | |
244 | * if (index >= array->map.max_entries) | |
245 | * goto out; | |
246 | */ | |
247 | PPC_LWZ(b2p[TMP_REG_1], b2p_bpf_array, offsetof(struct bpf_array, map.max_entries)); | |
248 | PPC_CMPLW(b2p_index, b2p[TMP_REG_1]); | |
249 | PPC_BCC(COND_GE, out); | |
250 | ||
251 | /* | |
252 | * if (tail_call_cnt > MAX_TAIL_CALL_CNT) | |
253 | * goto out; | |
254 | */ | |
255 | PPC_LD(b2p[TMP_REG_1], 1, bpf_jit_stack_tailcallcnt(ctx)); | |
256 | PPC_CMPLWI(b2p[TMP_REG_1], MAX_TAIL_CALL_CNT); | |
257 | PPC_BCC(COND_GT, out); | |
258 | ||
259 | /* | |
260 | * tail_call_cnt++; | |
261 | */ | |
262 | PPC_ADDI(b2p[TMP_REG_1], b2p[TMP_REG_1], 1); | |
263 | PPC_BPF_STL(b2p[TMP_REG_1], 1, bpf_jit_stack_tailcallcnt(ctx)); | |
264 | ||
265 | /* prog = array->ptrs[index]; */ | |
266 | PPC_MULI(b2p[TMP_REG_1], b2p_index, 8); | |
267 | PPC_ADD(b2p[TMP_REG_1], b2p[TMP_REG_1], b2p_bpf_array); | |
268 | PPC_LD(b2p[TMP_REG_1], b2p[TMP_REG_1], offsetof(struct bpf_array, ptrs)); | |
269 | ||
270 | /* | |
271 | * if (prog == NULL) | |
272 | * goto out; | |
273 | */ | |
274 | PPC_CMPLDI(b2p[TMP_REG_1], 0); | |
275 | PPC_BCC(COND_EQ, out); | |
276 | ||
277 | /* goto *(prog->bpf_func + prologue_size); */ | |
278 | PPC_LD(b2p[TMP_REG_1], b2p[TMP_REG_1], offsetof(struct bpf_prog, bpf_func)); | |
279 | #ifdef PPC64_ELF_ABI_v1 | |
280 | /* skip past the function descriptor */ | |
281 | PPC_ADDI(b2p[TMP_REG_1], b2p[TMP_REG_1], | |
282 | FUNCTION_DESCR_SIZE + BPF_TAILCALL_PROLOGUE_SIZE); | |
283 | #else | |
284 | PPC_ADDI(b2p[TMP_REG_1], b2p[TMP_REG_1], BPF_TAILCALL_PROLOGUE_SIZE); | |
285 | #endif | |
286 | PPC_MTCTR(b2p[TMP_REG_1]); | |
287 | ||
288 | /* tear down stack, restore NVRs, ... */ | |
289 | bpf_jit_emit_common_epilogue(image, ctx); | |
290 | ||
291 | PPC_BCTR(); | |
292 | /* out: */ | |
293 | } | |
294 | ||
156d0e29 NR |
295 | /* Assemble the body code between the prologue & epilogue */ |
296 | static int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, | |
297 | struct codegen_context *ctx, | |
298 | u32 *addrs) | |
299 | { | |
300 | const struct bpf_insn *insn = fp->insnsi; | |
301 | int flen = fp->len; | |
302 | int i; | |
303 | ||
304 | /* Start of epilogue code - will only be valid 2nd pass onwards */ | |
305 | u32 exit_addr = addrs[flen]; | |
306 | ||
307 | for (i = 0; i < flen; i++) { | |
308 | u32 code = insn[i].code; | |
309 | u32 dst_reg = b2p[insn[i].dst_reg]; | |
310 | u32 src_reg = b2p[insn[i].src_reg]; | |
311 | s16 off = insn[i].off; | |
312 | s32 imm = insn[i].imm; | |
313 | u64 imm64; | |
314 | u8 *func; | |
315 | u32 true_cond; | |
156d0e29 NR |
316 | |
317 | /* | |
318 | * addrs[] maps a BPF bytecode address into a real offset from | |
319 | * the start of the body code. | |
320 | */ | |
321 | addrs[i] = ctx->idx * 4; | |
322 | ||
323 | /* | |
324 | * As an optimization, we note down which non-volatile registers | |
325 | * are used so that we can only save/restore those in our | |
326 | * prologue and epilogue. We do this here regardless of whether | |
327 | * the actual BPF instruction uses src/dst registers or not | |
328 | * (for instance, BPF_CALL does not use them). The expectation | |
329 | * is that those instructions will have src_reg/dst_reg set to | |
330 | * 0. Even otherwise, we just lose some prologue/epilogue | |
331 | * optimization but everything else should work without | |
332 | * any issues. | |
333 | */ | |
7b847f52 | 334 | if (dst_reg >= BPF_PPC_NVR_MIN && dst_reg < 32) |
156d0e29 | 335 | bpf_set_seen_register(ctx, insn[i].dst_reg); |
7b847f52 | 336 | if (src_reg >= BPF_PPC_NVR_MIN && src_reg < 32) |
156d0e29 NR |
337 | bpf_set_seen_register(ctx, insn[i].src_reg); |
338 | ||
339 | switch (code) { | |
340 | /* | |
341 | * Arithmetic operations: ADD/SUB/MUL/DIV/MOD/NEG | |
342 | */ | |
343 | case BPF_ALU | BPF_ADD | BPF_X: /* (u32) dst += (u32) src */ | |
344 | case BPF_ALU64 | BPF_ADD | BPF_X: /* dst += src */ | |
345 | PPC_ADD(dst_reg, dst_reg, src_reg); | |
346 | goto bpf_alu32_trunc; | |
347 | case BPF_ALU | BPF_SUB | BPF_X: /* (u32) dst -= (u32) src */ | |
348 | case BPF_ALU64 | BPF_SUB | BPF_X: /* dst -= src */ | |
349 | PPC_SUB(dst_reg, dst_reg, src_reg); | |
350 | goto bpf_alu32_trunc; | |
351 | case BPF_ALU | BPF_ADD | BPF_K: /* (u32) dst += (u32) imm */ | |
352 | case BPF_ALU | BPF_SUB | BPF_K: /* (u32) dst -= (u32) imm */ | |
353 | case BPF_ALU64 | BPF_ADD | BPF_K: /* dst += imm */ | |
354 | case BPF_ALU64 | BPF_SUB | BPF_K: /* dst -= imm */ | |
355 | if (BPF_OP(code) == BPF_SUB) | |
356 | imm = -imm; | |
357 | if (imm) { | |
358 | if (imm >= -32768 && imm < 32768) | |
359 | PPC_ADDI(dst_reg, dst_reg, IMM_L(imm)); | |
360 | else { | |
361 | PPC_LI32(b2p[TMP_REG_1], imm); | |
362 | PPC_ADD(dst_reg, dst_reg, b2p[TMP_REG_1]); | |
363 | } | |
364 | } | |
365 | goto bpf_alu32_trunc; | |
366 | case BPF_ALU | BPF_MUL | BPF_X: /* (u32) dst *= (u32) src */ | |
367 | case BPF_ALU64 | BPF_MUL | BPF_X: /* dst *= src */ | |
368 | if (BPF_CLASS(code) == BPF_ALU) | |
369 | PPC_MULW(dst_reg, dst_reg, src_reg); | |
370 | else | |
371 | PPC_MULD(dst_reg, dst_reg, src_reg); | |
372 | goto bpf_alu32_trunc; | |
373 | case BPF_ALU | BPF_MUL | BPF_K: /* (u32) dst *= (u32) imm */ | |
374 | case BPF_ALU64 | BPF_MUL | BPF_K: /* dst *= imm */ | |
375 | if (imm >= -32768 && imm < 32768) | |
376 | PPC_MULI(dst_reg, dst_reg, IMM_L(imm)); | |
377 | else { | |
378 | PPC_LI32(b2p[TMP_REG_1], imm); | |
379 | if (BPF_CLASS(code) == BPF_ALU) | |
380 | PPC_MULW(dst_reg, dst_reg, | |
381 | b2p[TMP_REG_1]); | |
382 | else | |
383 | PPC_MULD(dst_reg, dst_reg, | |
384 | b2p[TMP_REG_1]); | |
385 | } | |
386 | goto bpf_alu32_trunc; | |
387 | case BPF_ALU | BPF_DIV | BPF_X: /* (u32) dst /= (u32) src */ | |
388 | case BPF_ALU | BPF_MOD | BPF_X: /* (u32) dst %= (u32) src */ | |
389 | PPC_CMPWI(src_reg, 0); | |
390 | PPC_BCC_SHORT(COND_NE, (ctx->idx * 4) + 12); | |
391 | PPC_LI(b2p[BPF_REG_0], 0); | |
392 | PPC_JMP(exit_addr); | |
393 | if (BPF_OP(code) == BPF_MOD) { | |
394 | PPC_DIVWU(b2p[TMP_REG_1], dst_reg, src_reg); | |
395 | PPC_MULW(b2p[TMP_REG_1], src_reg, | |
396 | b2p[TMP_REG_1]); | |
397 | PPC_SUB(dst_reg, dst_reg, b2p[TMP_REG_1]); | |
398 | } else | |
399 | PPC_DIVWU(dst_reg, dst_reg, src_reg); | |
400 | goto bpf_alu32_trunc; | |
401 | case BPF_ALU64 | BPF_DIV | BPF_X: /* dst /= src */ | |
402 | case BPF_ALU64 | BPF_MOD | BPF_X: /* dst %= src */ | |
403 | PPC_CMPDI(src_reg, 0); | |
404 | PPC_BCC_SHORT(COND_NE, (ctx->idx * 4) + 12); | |
405 | PPC_LI(b2p[BPF_REG_0], 0); | |
406 | PPC_JMP(exit_addr); | |
407 | if (BPF_OP(code) == BPF_MOD) { | |
408 | PPC_DIVD(b2p[TMP_REG_1], dst_reg, src_reg); | |
409 | PPC_MULD(b2p[TMP_REG_1], src_reg, | |
410 | b2p[TMP_REG_1]); | |
411 | PPC_SUB(dst_reg, dst_reg, b2p[TMP_REG_1]); | |
412 | } else | |
413 | PPC_DIVD(dst_reg, dst_reg, src_reg); | |
414 | break; | |
415 | case BPF_ALU | BPF_MOD | BPF_K: /* (u32) dst %= (u32) imm */ | |
416 | case BPF_ALU | BPF_DIV | BPF_K: /* (u32) dst /= (u32) imm */ | |
417 | case BPF_ALU64 | BPF_MOD | BPF_K: /* dst %= imm */ | |
418 | case BPF_ALU64 | BPF_DIV | BPF_K: /* dst /= imm */ | |
419 | if (imm == 0) | |
420 | return -EINVAL; | |
421 | else if (imm == 1) | |
422 | goto bpf_alu32_trunc; | |
423 | ||
424 | PPC_LI32(b2p[TMP_REG_1], imm); | |
425 | switch (BPF_CLASS(code)) { | |
426 | case BPF_ALU: | |
427 | if (BPF_OP(code) == BPF_MOD) { | |
428 | PPC_DIVWU(b2p[TMP_REG_2], dst_reg, | |
429 | b2p[TMP_REG_1]); | |
430 | PPC_MULW(b2p[TMP_REG_1], | |
431 | b2p[TMP_REG_1], | |
432 | b2p[TMP_REG_2]); | |
433 | PPC_SUB(dst_reg, dst_reg, | |
434 | b2p[TMP_REG_1]); | |
435 | } else | |
436 | PPC_DIVWU(dst_reg, dst_reg, | |
437 | b2p[TMP_REG_1]); | |
438 | break; | |
439 | case BPF_ALU64: | |
440 | if (BPF_OP(code) == BPF_MOD) { | |
441 | PPC_DIVD(b2p[TMP_REG_2], dst_reg, | |
442 | b2p[TMP_REG_1]); | |
443 | PPC_MULD(b2p[TMP_REG_1], | |
444 | b2p[TMP_REG_1], | |
445 | b2p[TMP_REG_2]); | |
446 | PPC_SUB(dst_reg, dst_reg, | |
447 | b2p[TMP_REG_1]); | |
448 | } else | |
449 | PPC_DIVD(dst_reg, dst_reg, | |
450 | b2p[TMP_REG_1]); | |
451 | break; | |
452 | } | |
453 | goto bpf_alu32_trunc; | |
454 | case BPF_ALU | BPF_NEG: /* (u32) dst = -dst */ | |
455 | case BPF_ALU64 | BPF_NEG: /* dst = -dst */ | |
456 | PPC_NEG(dst_reg, dst_reg); | |
457 | goto bpf_alu32_trunc; | |
458 | ||
459 | /* | |
460 | * Logical operations: AND/OR/XOR/[A]LSH/[A]RSH | |
461 | */ | |
462 | case BPF_ALU | BPF_AND | BPF_X: /* (u32) dst = dst & src */ | |
463 | case BPF_ALU64 | BPF_AND | BPF_X: /* dst = dst & src */ | |
464 | PPC_AND(dst_reg, dst_reg, src_reg); | |
465 | goto bpf_alu32_trunc; | |
466 | case BPF_ALU | BPF_AND | BPF_K: /* (u32) dst = dst & imm */ | |
467 | case BPF_ALU64 | BPF_AND | BPF_K: /* dst = dst & imm */ | |
468 | if (!IMM_H(imm)) | |
469 | PPC_ANDI(dst_reg, dst_reg, IMM_L(imm)); | |
470 | else { | |
471 | /* Sign-extended */ | |
472 | PPC_LI32(b2p[TMP_REG_1], imm); | |
473 | PPC_AND(dst_reg, dst_reg, b2p[TMP_REG_1]); | |
474 | } | |
475 | goto bpf_alu32_trunc; | |
476 | case BPF_ALU | BPF_OR | BPF_X: /* dst = (u32) dst | (u32) src */ | |
477 | case BPF_ALU64 | BPF_OR | BPF_X: /* dst = dst | src */ | |
478 | PPC_OR(dst_reg, dst_reg, src_reg); | |
479 | goto bpf_alu32_trunc; | |
480 | case BPF_ALU | BPF_OR | BPF_K:/* dst = (u32) dst | (u32) imm */ | |
481 | case BPF_ALU64 | BPF_OR | BPF_K:/* dst = dst | imm */ | |
482 | if (imm < 0 && BPF_CLASS(code) == BPF_ALU64) { | |
483 | /* Sign-extended */ | |
484 | PPC_LI32(b2p[TMP_REG_1], imm); | |
485 | PPC_OR(dst_reg, dst_reg, b2p[TMP_REG_1]); | |
486 | } else { | |
487 | if (IMM_L(imm)) | |
488 | PPC_ORI(dst_reg, dst_reg, IMM_L(imm)); | |
489 | if (IMM_H(imm)) | |
490 | PPC_ORIS(dst_reg, dst_reg, IMM_H(imm)); | |
491 | } | |
492 | goto bpf_alu32_trunc; | |
493 | case BPF_ALU | BPF_XOR | BPF_X: /* (u32) dst ^= src */ | |
494 | case BPF_ALU64 | BPF_XOR | BPF_X: /* dst ^= src */ | |
495 | PPC_XOR(dst_reg, dst_reg, src_reg); | |
496 | goto bpf_alu32_trunc; | |
497 | case BPF_ALU | BPF_XOR | BPF_K: /* (u32) dst ^= (u32) imm */ | |
498 | case BPF_ALU64 | BPF_XOR | BPF_K: /* dst ^= imm */ | |
499 | if (imm < 0 && BPF_CLASS(code) == BPF_ALU64) { | |
500 | /* Sign-extended */ | |
501 | PPC_LI32(b2p[TMP_REG_1], imm); | |
502 | PPC_XOR(dst_reg, dst_reg, b2p[TMP_REG_1]); | |
503 | } else { | |
504 | if (IMM_L(imm)) | |
505 | PPC_XORI(dst_reg, dst_reg, IMM_L(imm)); | |
506 | if (IMM_H(imm)) | |
507 | PPC_XORIS(dst_reg, dst_reg, IMM_H(imm)); | |
508 | } | |
509 | goto bpf_alu32_trunc; | |
510 | case BPF_ALU | BPF_LSH | BPF_X: /* (u32) dst <<= (u32) src */ | |
511 | /* slw clears top 32 bits */ | |
512 | PPC_SLW(dst_reg, dst_reg, src_reg); | |
513 | break; | |
514 | case BPF_ALU64 | BPF_LSH | BPF_X: /* dst <<= src; */ | |
515 | PPC_SLD(dst_reg, dst_reg, src_reg); | |
516 | break; | |
517 | case BPF_ALU | BPF_LSH | BPF_K: /* (u32) dst <<== (u32) imm */ | |
518 | /* with imm 0, we still need to clear top 32 bits */ | |
519 | PPC_SLWI(dst_reg, dst_reg, imm); | |
520 | break; | |
521 | case BPF_ALU64 | BPF_LSH | BPF_K: /* dst <<== imm */ | |
522 | if (imm != 0) | |
523 | PPC_SLDI(dst_reg, dst_reg, imm); | |
524 | break; | |
525 | case BPF_ALU | BPF_RSH | BPF_X: /* (u32) dst >>= (u32) src */ | |
526 | PPC_SRW(dst_reg, dst_reg, src_reg); | |
527 | break; | |
528 | case BPF_ALU64 | BPF_RSH | BPF_X: /* dst >>= src */ | |
529 | PPC_SRD(dst_reg, dst_reg, src_reg); | |
530 | break; | |
531 | case BPF_ALU | BPF_RSH | BPF_K: /* (u32) dst >>= (u32) imm */ | |
532 | PPC_SRWI(dst_reg, dst_reg, imm); | |
533 | break; | |
534 | case BPF_ALU64 | BPF_RSH | BPF_K: /* dst >>= imm */ | |
535 | if (imm != 0) | |
536 | PPC_SRDI(dst_reg, dst_reg, imm); | |
537 | break; | |
538 | case BPF_ALU64 | BPF_ARSH | BPF_X: /* (s64) dst >>= src */ | |
539 | PPC_SRAD(dst_reg, dst_reg, src_reg); | |
540 | break; | |
541 | case BPF_ALU64 | BPF_ARSH | BPF_K: /* (s64) dst >>= imm */ | |
542 | if (imm != 0) | |
543 | PPC_SRADI(dst_reg, dst_reg, imm); | |
544 | break; | |
545 | ||
546 | /* | |
547 | * MOV | |
548 | */ | |
549 | case BPF_ALU | BPF_MOV | BPF_X: /* (u32) dst = src */ | |
550 | case BPF_ALU64 | BPF_MOV | BPF_X: /* dst = src */ | |
551 | PPC_MR(dst_reg, src_reg); | |
552 | goto bpf_alu32_trunc; | |
553 | case BPF_ALU | BPF_MOV | BPF_K: /* (u32) dst = imm */ | |
554 | case BPF_ALU64 | BPF_MOV | BPF_K: /* dst = (s64) imm */ | |
555 | PPC_LI32(dst_reg, imm); | |
556 | if (imm < 0) | |
557 | goto bpf_alu32_trunc; | |
558 | break; | |
559 | ||
560 | bpf_alu32_trunc: | |
561 | /* Truncate to 32-bits */ | |
562 | if (BPF_CLASS(code) == BPF_ALU) | |
563 | PPC_RLWINM(dst_reg, dst_reg, 0, 0, 31); | |
564 | break; | |
565 | ||
566 | /* | |
567 | * BPF_FROM_BE/LE | |
568 | */ | |
569 | case BPF_ALU | BPF_END | BPF_FROM_LE: | |
570 | case BPF_ALU | BPF_END | BPF_FROM_BE: | |
571 | #ifdef __BIG_ENDIAN__ | |
572 | if (BPF_SRC(code) == BPF_FROM_BE) | |
573 | goto emit_clear; | |
574 | #else /* !__BIG_ENDIAN__ */ | |
575 | if (BPF_SRC(code) == BPF_FROM_LE) | |
576 | goto emit_clear; | |
577 | #endif | |
578 | switch (imm) { | |
579 | case 16: | |
580 | /* Rotate 8 bits left & mask with 0x0000ff00 */ | |
581 | PPC_RLWINM(b2p[TMP_REG_1], dst_reg, 8, 16, 23); | |
582 | /* Rotate 8 bits right & insert LSB to reg */ | |
583 | PPC_RLWIMI(b2p[TMP_REG_1], dst_reg, 24, 24, 31); | |
584 | /* Move result back to dst_reg */ | |
585 | PPC_MR(dst_reg, b2p[TMP_REG_1]); | |
586 | break; | |
587 | case 32: | |
588 | /* | |
589 | * Rotate word left by 8 bits: | |
590 | * 2 bytes are already in their final position | |
591 | * -- byte 2 and 4 (of bytes 1, 2, 3 and 4) | |
592 | */ | |
593 | PPC_RLWINM(b2p[TMP_REG_1], dst_reg, 8, 0, 31); | |
594 | /* Rotate 24 bits and insert byte 1 */ | |
595 | PPC_RLWIMI(b2p[TMP_REG_1], dst_reg, 24, 0, 7); | |
596 | /* Rotate 24 bits and insert byte 3 */ | |
597 | PPC_RLWIMI(b2p[TMP_REG_1], dst_reg, 24, 16, 23); | |
598 | PPC_MR(dst_reg, b2p[TMP_REG_1]); | |
599 | break; | |
600 | case 64: | |
601 | /* | |
602 | * Way easier and faster(?) to store the value | |
603 | * into stack and then use ldbrx | |
604 | * | |
156d0e29 NR |
605 | * ctx->seen will be reliable in pass2, but |
606 | * the instructions generated will remain the | |
607 | * same across all passes | |
608 | */ | |
7b847f52 NR |
609 | PPC_STD(dst_reg, 1, bpf_jit_stack_local(ctx)); |
610 | PPC_ADDI(b2p[TMP_REG_1], 1, bpf_jit_stack_local(ctx)); | |
156d0e29 NR |
611 | PPC_LDBRX(dst_reg, 0, b2p[TMP_REG_1]); |
612 | break; | |
613 | } | |
614 | break; | |
615 | ||
616 | emit_clear: | |
617 | switch (imm) { | |
618 | case 16: | |
619 | /* zero-extend 16 bits into 64 bits */ | |
620 | PPC_RLDICL(dst_reg, dst_reg, 0, 48); | |
621 | break; | |
622 | case 32: | |
623 | /* zero-extend 32 bits into 64 bits */ | |
624 | PPC_RLDICL(dst_reg, dst_reg, 0, 32); | |
625 | break; | |
626 | case 64: | |
627 | /* nop */ | |
628 | break; | |
629 | } | |
630 | break; | |
631 | ||
632 | /* | |
633 | * BPF_ST(X) | |
634 | */ | |
635 | case BPF_STX | BPF_MEM | BPF_B: /* *(u8 *)(dst + off) = src */ | |
636 | case BPF_ST | BPF_MEM | BPF_B: /* *(u8 *)(dst + off) = imm */ | |
637 | if (BPF_CLASS(code) == BPF_ST) { | |
638 | PPC_LI(b2p[TMP_REG_1], imm); | |
639 | src_reg = b2p[TMP_REG_1]; | |
640 | } | |
641 | PPC_STB(src_reg, dst_reg, off); | |
642 | break; | |
643 | case BPF_STX | BPF_MEM | BPF_H: /* (u16 *)(dst + off) = src */ | |
644 | case BPF_ST | BPF_MEM | BPF_H: /* (u16 *)(dst + off) = imm */ | |
645 | if (BPF_CLASS(code) == BPF_ST) { | |
646 | PPC_LI(b2p[TMP_REG_1], imm); | |
647 | src_reg = b2p[TMP_REG_1]; | |
648 | } | |
649 | PPC_STH(src_reg, dst_reg, off); | |
650 | break; | |
651 | case BPF_STX | BPF_MEM | BPF_W: /* *(u32 *)(dst + off) = src */ | |
652 | case BPF_ST | BPF_MEM | BPF_W: /* *(u32 *)(dst + off) = imm */ | |
653 | if (BPF_CLASS(code) == BPF_ST) { | |
654 | PPC_LI32(b2p[TMP_REG_1], imm); | |
655 | src_reg = b2p[TMP_REG_1]; | |
656 | } | |
657 | PPC_STW(src_reg, dst_reg, off); | |
658 | break; | |
659 | case BPF_STX | BPF_MEM | BPF_DW: /* (u64 *)(dst + off) = src */ | |
660 | case BPF_ST | BPF_MEM | BPF_DW: /* *(u64 *)(dst + off) = imm */ | |
661 | if (BPF_CLASS(code) == BPF_ST) { | |
662 | PPC_LI32(b2p[TMP_REG_1], imm); | |
663 | src_reg = b2p[TMP_REG_1]; | |
664 | } | |
665 | PPC_STD(src_reg, dst_reg, off); | |
666 | break; | |
667 | ||
668 | /* | |
669 | * BPF_STX XADD (atomic_add) | |
670 | */ | |
671 | /* *(u32 *)(dst + off) += src */ | |
672 | case BPF_STX | BPF_XADD | BPF_W: | |
673 | /* Get EA into TMP_REG_1 */ | |
674 | PPC_ADDI(b2p[TMP_REG_1], dst_reg, off); | |
675 | /* error if EA is not word-aligned */ | |
676 | PPC_ANDI(b2p[TMP_REG_2], b2p[TMP_REG_1], 0x03); | |
677 | PPC_BCC_SHORT(COND_EQ, (ctx->idx * 4) + 12); | |
678 | PPC_LI(b2p[BPF_REG_0], 0); | |
679 | PPC_JMP(exit_addr); | |
680 | /* load value from memory into TMP_REG_2 */ | |
681 | PPC_BPF_LWARX(b2p[TMP_REG_2], 0, b2p[TMP_REG_1], 0); | |
682 | /* add value from src_reg into this */ | |
683 | PPC_ADD(b2p[TMP_REG_2], b2p[TMP_REG_2], src_reg); | |
684 | /* store result back */ | |
685 | PPC_BPF_STWCX(b2p[TMP_REG_2], 0, b2p[TMP_REG_1]); | |
686 | /* we're done if this succeeded */ | |
687 | PPC_BCC_SHORT(COND_EQ, (ctx->idx * 4) + (7*4)); | |
688 | /* otherwise, let's try once more */ | |
689 | PPC_BPF_LWARX(b2p[TMP_REG_2], 0, b2p[TMP_REG_1], 0); | |
690 | PPC_ADD(b2p[TMP_REG_2], b2p[TMP_REG_2], src_reg); | |
691 | PPC_BPF_STWCX(b2p[TMP_REG_2], 0, b2p[TMP_REG_1]); | |
692 | /* exit if the store was not successful */ | |
693 | PPC_LI(b2p[BPF_REG_0], 0); | |
694 | PPC_BCC(COND_NE, exit_addr); | |
695 | break; | |
696 | /* *(u64 *)(dst + off) += src */ | |
697 | case BPF_STX | BPF_XADD | BPF_DW: | |
698 | PPC_ADDI(b2p[TMP_REG_1], dst_reg, off); | |
699 | /* error if EA is not doubleword-aligned */ | |
700 | PPC_ANDI(b2p[TMP_REG_2], b2p[TMP_REG_1], 0x07); | |
701 | PPC_BCC_SHORT(COND_EQ, (ctx->idx * 4) + (3*4)); | |
702 | PPC_LI(b2p[BPF_REG_0], 0); | |
703 | PPC_JMP(exit_addr); | |
704 | PPC_BPF_LDARX(b2p[TMP_REG_2], 0, b2p[TMP_REG_1], 0); | |
705 | PPC_ADD(b2p[TMP_REG_2], b2p[TMP_REG_2], src_reg); | |
706 | PPC_BPF_STDCX(b2p[TMP_REG_2], 0, b2p[TMP_REG_1]); | |
707 | PPC_BCC_SHORT(COND_EQ, (ctx->idx * 4) + (7*4)); | |
708 | PPC_BPF_LDARX(b2p[TMP_REG_2], 0, b2p[TMP_REG_1], 0); | |
709 | PPC_ADD(b2p[TMP_REG_2], b2p[TMP_REG_2], src_reg); | |
710 | PPC_BPF_STDCX(b2p[TMP_REG_2], 0, b2p[TMP_REG_1]); | |
711 | PPC_LI(b2p[BPF_REG_0], 0); | |
712 | PPC_BCC(COND_NE, exit_addr); | |
713 | break; | |
714 | ||
715 | /* | |
716 | * BPF_LDX | |
717 | */ | |
718 | /* dst = *(u8 *)(ul) (src + off) */ | |
719 | case BPF_LDX | BPF_MEM | BPF_B: | |
720 | PPC_LBZ(dst_reg, src_reg, off); | |
721 | break; | |
722 | /* dst = *(u16 *)(ul) (src + off) */ | |
723 | case BPF_LDX | BPF_MEM | BPF_H: | |
724 | PPC_LHZ(dst_reg, src_reg, off); | |
725 | break; | |
726 | /* dst = *(u32 *)(ul) (src + off) */ | |
727 | case BPF_LDX | BPF_MEM | BPF_W: | |
728 | PPC_LWZ(dst_reg, src_reg, off); | |
729 | break; | |
730 | /* dst = *(u64 *)(ul) (src + off) */ | |
731 | case BPF_LDX | BPF_MEM | BPF_DW: | |
732 | PPC_LD(dst_reg, src_reg, off); | |
733 | break; | |
734 | ||
735 | /* | |
736 | * Doubleword load | |
737 | * 16 byte instruction that uses two 'struct bpf_insn' | |
738 | */ | |
739 | case BPF_LD | BPF_IMM | BPF_DW: /* dst = (u64) imm */ | |
740 | imm64 = ((u64)(u32) insn[i].imm) | | |
741 | (((u64)(u32) insn[i+1].imm) << 32); | |
742 | /* Adjust for two bpf instructions */ | |
743 | addrs[++i] = ctx->idx * 4; | |
744 | PPC_LI64(dst_reg, imm64); | |
745 | break; | |
746 | ||
747 | /* | |
748 | * Return/Exit | |
749 | */ | |
750 | case BPF_JMP | BPF_EXIT: | |
751 | /* | |
752 | * If this isn't the very last instruction, branch to | |
753 | * the epilogue. If we _are_ the last instruction, | |
754 | * we'll just fall through to the epilogue. | |
755 | */ | |
756 | if (i != flen - 1) | |
757 | PPC_JMP(exit_addr); | |
758 | /* else fall through to the epilogue */ | |
759 | break; | |
760 | ||
761 | /* | |
762 | * Call kernel helper | |
763 | */ | |
764 | case BPF_JMP | BPF_CALL: | |
765 | ctx->seen |= SEEN_FUNC; | |
766 | func = (u8 *) __bpf_call_base + imm; | |
767 | ||
768 | /* Save skb pointer if we need to re-cache skb data */ | |
17bedab2 | 769 | if (bpf_helper_changes_pkt_data(func)) |
7b847f52 | 770 | PPC_BPF_STL(3, 1, bpf_jit_stack_local(ctx)); |
156d0e29 NR |
771 | |
772 | bpf_jit_emit_func_call(image, ctx, (u64)func); | |
773 | ||
774 | /* move return value from r3 to BPF_REG_0 */ | |
775 | PPC_MR(b2p[BPF_REG_0], 3); | |
776 | ||
777 | /* refresh skb cache */ | |
17bedab2 | 778 | if (bpf_helper_changes_pkt_data(func)) { |
156d0e29 | 779 | /* reload skb pointer to r3 */ |
7b847f52 | 780 | PPC_BPF_LL(3, 1, bpf_jit_stack_local(ctx)); |
156d0e29 NR |
781 | bpf_jit_emit_skb_loads(image, ctx); |
782 | } | |
783 | break; | |
784 | ||
785 | /* | |
786 | * Jumps and branches | |
787 | */ | |
788 | case BPF_JMP | BPF_JA: | |
789 | PPC_JMP(addrs[i + 1 + off]); | |
790 | break; | |
791 | ||
792 | case BPF_JMP | BPF_JGT | BPF_K: | |
793 | case BPF_JMP | BPF_JGT | BPF_X: | |
794 | case BPF_JMP | BPF_JSGT | BPF_K: | |
795 | case BPF_JMP | BPF_JSGT | BPF_X: | |
796 | true_cond = COND_GT; | |
797 | goto cond_branch; | |
798 | case BPF_JMP | BPF_JGE | BPF_K: | |
799 | case BPF_JMP | BPF_JGE | BPF_X: | |
800 | case BPF_JMP | BPF_JSGE | BPF_K: | |
801 | case BPF_JMP | BPF_JSGE | BPF_X: | |
802 | true_cond = COND_GE; | |
803 | goto cond_branch; | |
804 | case BPF_JMP | BPF_JEQ | BPF_K: | |
805 | case BPF_JMP | BPF_JEQ | BPF_X: | |
806 | true_cond = COND_EQ; | |
807 | goto cond_branch; | |
808 | case BPF_JMP | BPF_JNE | BPF_K: | |
809 | case BPF_JMP | BPF_JNE | BPF_X: | |
810 | true_cond = COND_NE; | |
811 | goto cond_branch; | |
812 | case BPF_JMP | BPF_JSET | BPF_K: | |
813 | case BPF_JMP | BPF_JSET | BPF_X: | |
814 | true_cond = COND_NE; | |
815 | /* Fall through */ | |
816 | ||
817 | cond_branch: | |
818 | switch (code) { | |
819 | case BPF_JMP | BPF_JGT | BPF_X: | |
820 | case BPF_JMP | BPF_JGE | BPF_X: | |
821 | case BPF_JMP | BPF_JEQ | BPF_X: | |
822 | case BPF_JMP | BPF_JNE | BPF_X: | |
823 | /* unsigned comparison */ | |
824 | PPC_CMPLD(dst_reg, src_reg); | |
825 | break; | |
826 | case BPF_JMP | BPF_JSGT | BPF_X: | |
827 | case BPF_JMP | BPF_JSGE | BPF_X: | |
828 | /* signed comparison */ | |
829 | PPC_CMPD(dst_reg, src_reg); | |
830 | break; | |
831 | case BPF_JMP | BPF_JSET | BPF_X: | |
832 | PPC_AND_DOT(b2p[TMP_REG_1], dst_reg, src_reg); | |
833 | break; | |
834 | case BPF_JMP | BPF_JNE | BPF_K: | |
835 | case BPF_JMP | BPF_JEQ | BPF_K: | |
836 | case BPF_JMP | BPF_JGT | BPF_K: | |
837 | case BPF_JMP | BPF_JGE | BPF_K: | |
838 | /* | |
839 | * Need sign-extended load, so only positive | |
840 | * values can be used as imm in cmpldi | |
841 | */ | |
842 | if (imm >= 0 && imm < 32768) | |
843 | PPC_CMPLDI(dst_reg, imm); | |
844 | else { | |
845 | /* sign-extending load */ | |
846 | PPC_LI32(b2p[TMP_REG_1], imm); | |
847 | /* ... but unsigned comparison */ | |
848 | PPC_CMPLD(dst_reg, b2p[TMP_REG_1]); | |
849 | } | |
850 | break; | |
851 | case BPF_JMP | BPF_JSGT | BPF_K: | |
852 | case BPF_JMP | BPF_JSGE | BPF_K: | |
853 | /* | |
854 | * signed comparison, so any 16-bit value | |
855 | * can be used in cmpdi | |
856 | */ | |
857 | if (imm >= -32768 && imm < 32768) | |
858 | PPC_CMPDI(dst_reg, imm); | |
859 | else { | |
860 | PPC_LI32(b2p[TMP_REG_1], imm); | |
861 | PPC_CMPD(dst_reg, b2p[TMP_REG_1]); | |
862 | } | |
863 | break; | |
864 | case BPF_JMP | BPF_JSET | BPF_K: | |
865 | /* andi does not sign-extend the immediate */ | |
866 | if (imm >= 0 && imm < 32768) | |
867 | /* PPC_ANDI is _only/always_ dot-form */ | |
868 | PPC_ANDI(b2p[TMP_REG_1], dst_reg, imm); | |
869 | else { | |
870 | PPC_LI32(b2p[TMP_REG_1], imm); | |
871 | PPC_AND_DOT(b2p[TMP_REG_1], dst_reg, | |
872 | b2p[TMP_REG_1]); | |
873 | } | |
874 | break; | |
875 | } | |
876 | PPC_BCC(true_cond, addrs[i + 1 + off]); | |
877 | break; | |
878 | ||
879 | /* | |
880 | * Loads from packet header/data | |
881 | * Assume 32-bit input value in imm and X (src_reg) | |
882 | */ | |
883 | ||
884 | /* Absolute loads */ | |
885 | case BPF_LD | BPF_W | BPF_ABS: | |
886 | func = (u8 *)CHOOSE_LOAD_FUNC(imm, sk_load_word); | |
887 | goto common_load_abs; | |
888 | case BPF_LD | BPF_H | BPF_ABS: | |
889 | func = (u8 *)CHOOSE_LOAD_FUNC(imm, sk_load_half); | |
890 | goto common_load_abs; | |
891 | case BPF_LD | BPF_B | BPF_ABS: | |
892 | func = (u8 *)CHOOSE_LOAD_FUNC(imm, sk_load_byte); | |
893 | common_load_abs: | |
894 | /* | |
895 | * Load from [imm] | |
896 | * Load into r4, which can just be passed onto | |
897 | * skb load helpers as the second parameter | |
898 | */ | |
899 | PPC_LI32(4, imm); | |
900 | goto common_load; | |
901 | ||
902 | /* Indirect loads */ | |
903 | case BPF_LD | BPF_W | BPF_IND: | |
904 | func = (u8 *)sk_load_word; | |
905 | goto common_load_ind; | |
906 | case BPF_LD | BPF_H | BPF_IND: | |
907 | func = (u8 *)sk_load_half; | |
908 | goto common_load_ind; | |
909 | case BPF_LD | BPF_B | BPF_IND: | |
910 | func = (u8 *)sk_load_byte; | |
911 | common_load_ind: | |
912 | /* | |
913 | * Load from [src_reg + imm] | |
914 | * Treat src_reg as a 32-bit value | |
915 | */ | |
916 | PPC_EXTSW(4, src_reg); | |
917 | if (imm) { | |
918 | if (imm >= -32768 && imm < 32768) | |
919 | PPC_ADDI(4, 4, IMM_L(imm)); | |
920 | else { | |
921 | PPC_LI32(b2p[TMP_REG_1], imm); | |
922 | PPC_ADD(4, 4, b2p[TMP_REG_1]); | |
923 | } | |
924 | } | |
925 | ||
926 | common_load: | |
927 | ctx->seen |= SEEN_SKB; | |
928 | ctx->seen |= SEEN_FUNC; | |
929 | bpf_jit_emit_func_call(image, ctx, (u64)func); | |
930 | ||
931 | /* | |
932 | * Helper returns 'lt' condition on error, and an | |
933 | * appropriate return value in BPF_REG_0 | |
934 | */ | |
935 | PPC_BCC(COND_LT, exit_addr); | |
936 | break; | |
937 | ||
938 | /* | |
ce076141 | 939 | * Tail call |
156d0e29 NR |
940 | */ |
941 | case BPF_JMP | BPF_CALL | BPF_X: | |
ce076141 NR |
942 | ctx->seen |= SEEN_TAILCALL; |
943 | bpf_jit_emit_tail_call(image, ctx, addrs[i + 1]); | |
944 | break; | |
156d0e29 NR |
945 | |
946 | default: | |
947 | /* | |
948 | * The filter contains something cruel & unusual. | |
949 | * We don't handle it, but also there shouldn't be | |
950 | * anything missing from our list. | |
951 | */ | |
952 | pr_err_ratelimited("eBPF filter opcode %04x (@%d) unsupported\n", | |
953 | code, i); | |
954 | return -ENOTSUPP; | |
955 | } | |
956 | } | |
957 | ||
958 | /* Set end-of-body-code address for exit. */ | |
959 | addrs[i] = ctx->idx * 4; | |
960 | ||
961 | return 0; | |
962 | } | |
963 | ||
964 | void bpf_jit_compile(struct bpf_prog *fp) { } | |
965 | ||
966 | struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp) | |
967 | { | |
968 | u32 proglen; | |
969 | u32 alloclen; | |
970 | u8 *image = NULL; | |
971 | u32 *code_base; | |
972 | u32 *addrs; | |
973 | struct codegen_context cgctx; | |
974 | int pass; | |
975 | int flen; | |
976 | struct bpf_binary_header *bpf_hdr; | |
b7b7013c NR |
977 | struct bpf_prog *org_fp = fp; |
978 | struct bpf_prog *tmp_fp; | |
979 | bool bpf_blinded = false; | |
156d0e29 NR |
980 | |
981 | if (!bpf_jit_enable) | |
b7b7013c NR |
982 | return org_fp; |
983 | ||
984 | tmp_fp = bpf_jit_blind_constants(org_fp); | |
985 | if (IS_ERR(tmp_fp)) | |
986 | return org_fp; | |
987 | ||
988 | if (tmp_fp != org_fp) { | |
989 | bpf_blinded = true; | |
990 | fp = tmp_fp; | |
991 | } | |
156d0e29 NR |
992 | |
993 | flen = fp->len; | |
994 | addrs = kzalloc((flen+1) * sizeof(*addrs), GFP_KERNEL); | |
b7b7013c NR |
995 | if (addrs == NULL) { |
996 | fp = org_fp; | |
997 | goto out; | |
998 | } | |
999 | ||
1000 | memset(&cgctx, 0, sizeof(struct codegen_context)); | |
156d0e29 | 1001 | |
156d0e29 | 1002 | /* Scouting faux-generate pass 0 */ |
b7b7013c | 1003 | if (bpf_jit_build_body(fp, 0, &cgctx, addrs)) { |
156d0e29 | 1004 | /* We hit something illegal or unsupported. */ |
b7b7013c | 1005 | fp = org_fp; |
156d0e29 | 1006 | goto out; |
b7b7013c | 1007 | } |
156d0e29 NR |
1008 | |
1009 | /* | |
1010 | * Pretend to build prologue, given the features we've seen. This will | |
1011 | * update ctgtx.idx as it pretends to output instructions, then we can | |
1012 | * calculate total size from idx. | |
1013 | */ | |
1014 | bpf_jit_build_prologue(0, &cgctx); | |
1015 | bpf_jit_build_epilogue(0, &cgctx); | |
1016 | ||
1017 | proglen = cgctx.idx * 4; | |
1018 | alloclen = proglen + FUNCTION_DESCR_SIZE; | |
1019 | ||
1020 | bpf_hdr = bpf_jit_binary_alloc(alloclen, &image, 4, | |
1021 | bpf_jit_fill_ill_insns); | |
b7b7013c NR |
1022 | if (!bpf_hdr) { |
1023 | fp = org_fp; | |
156d0e29 | 1024 | goto out; |
b7b7013c | 1025 | } |
156d0e29 NR |
1026 | |
1027 | code_base = (u32 *)(image + FUNCTION_DESCR_SIZE); | |
1028 | ||
1029 | /* Code generation passes 1-2 */ | |
1030 | for (pass = 1; pass < 3; pass++) { | |
1031 | /* Now build the prologue, body code & epilogue for real. */ | |
1032 | cgctx.idx = 0; | |
1033 | bpf_jit_build_prologue(code_base, &cgctx); | |
1034 | bpf_jit_build_body(fp, code_base, &cgctx, addrs); | |
1035 | bpf_jit_build_epilogue(code_base, &cgctx); | |
1036 | ||
1037 | if (bpf_jit_enable > 1) | |
1038 | pr_info("Pass %d: shrink = %d, seen = 0x%x\n", pass, | |
1039 | proglen - (cgctx.idx * 4), cgctx.seen); | |
1040 | } | |
1041 | ||
1042 | if (bpf_jit_enable > 1) | |
1043 | /* | |
1044 | * Note that we output the base address of the code_base | |
1045 | * rather than image, since opcodes are in code_base. | |
1046 | */ | |
1047 | bpf_jit_dump(flen, proglen, pass, code_base); | |
1048 | ||
1049 | if (image) { | |
1050 | bpf_flush_icache(bpf_hdr, image + alloclen); | |
1051 | #ifdef PPC64_ELF_ABI_v1 | |
1052 | /* Function descriptor nastiness: Address + TOC */ | |
1053 | ((u64 *)image)[0] = (u64)code_base; | |
1054 | ((u64 *)image)[1] = local_paca->kernel_toc; | |
1055 | #endif | |
1056 | fp->bpf_func = (void *)image; | |
1057 | fp->jited = 1; | |
1058 | } | |
1059 | ||
1060 | out: | |
1061 | kfree(addrs); | |
b7b7013c NR |
1062 | |
1063 | if (bpf_blinded) | |
1064 | bpf_jit_prog_release_other(fp, fp == org_fp ? tmp_fp : org_fp); | |
1065 | ||
156d0e29 NR |
1066 | return fp; |
1067 | } | |
1068 | ||
1069 | void bpf_jit_free(struct bpf_prog *fp) | |
1070 | { | |
1071 | unsigned long addr = (unsigned long)fp->bpf_func & PAGE_MASK; | |
1072 | struct bpf_binary_header *bpf_hdr = (void *)addr; | |
1073 | ||
1074 | if (fp->jited) | |
1075 | bpf_jit_binary_free(bpf_hdr); | |
1076 | ||
1077 | bpf_prog_unlock_free(fp); | |
1078 | } |