2 * bpf_jit_comp64.c: eBPF JIT compiler
4 * Copyright 2016 Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
7 * Based on the powerpc classic BPF JIT compiler by Matt Evans
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
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>
20 #include <linux/bpf.h>
22 #include "bpf_jit64.h"
24 int bpf_jit_enable __read_mostly;
26 static void bpf_jit_fill_ill_insns(void *area, unsigned int size)
28 memset32(area, BREAKPOINT_INSTRUCTION, size/4);
31 static inline void bpf_flush_icache(void *start, void *end)
34 flush_icache_range((unsigned long)start, (unsigned long)end);
37 static inline bool bpf_is_seen_register(struct codegen_context *ctx, int i)
39 return (ctx->seen & (1 << (31 - b2p[i])));
42 static inline void bpf_set_seen_register(struct codegen_context *ctx, int i)
44 ctx->seen |= (1 << (31 - b2p[i]));
47 static inline bool bpf_has_stack_frame(struct codegen_context *ctx)
50 * We only need a stack frame if:
51 * - we call other functions (kernel helpers), or
52 * - the bpf program uses its stack area
53 * The latter condition is deduced from the usage of BPF_REG_FP
55 return ctx->seen & SEEN_FUNC || bpf_is_seen_register(ctx, BPF_REG_FP);
59 * When not setting up our own stackframe, the redzone usage is:
61 * [ prev sp ] <-------------
63 * sp (r1) ---> [ stack pointer ] --------------
64 * [ nv gpr save area ] 8*8
67 * [ unused red zone ] 208 bytes protected
69 static int bpf_jit_stack_local(struct codegen_context *ctx)
71 if (bpf_has_stack_frame(ctx))
72 return STACK_FRAME_MIN_SIZE + ctx->stack_size;
74 return -(BPF_PPC_STACK_SAVE + 16);
77 static int bpf_jit_stack_tailcallcnt(struct codegen_context *ctx)
79 return bpf_jit_stack_local(ctx) + 8;
82 static int bpf_jit_stack_offsetof(struct codegen_context *ctx, int reg)
84 if (reg >= BPF_PPC_NVR_MIN && reg < 32)
85 return (bpf_has_stack_frame(ctx) ?
86 (BPF_PPC_STACKFRAME + ctx->stack_size) : 0)
89 pr_err("BPF JIT is asking about unknown registers");
93 static void bpf_jit_emit_skb_loads(u32 *image, struct codegen_context *ctx)
96 * Load skb->len and skb->data_len
99 PPC_LWZ(b2p[SKB_HLEN_REG], 3, offsetof(struct sk_buff, len));
100 PPC_LWZ(b2p[TMP_REG_1], 3, offsetof(struct sk_buff, data_len));
101 /* header_len = len - data_len */
102 PPC_SUB(b2p[SKB_HLEN_REG], b2p[SKB_HLEN_REG], b2p[TMP_REG_1]);
104 /* skb->data pointer */
105 PPC_BPF_LL(b2p[SKB_DATA_REG], 3, offsetof(struct sk_buff, data));
108 static void bpf_jit_build_prologue(u32 *image, struct codegen_context *ctx)
113 * Initialize tail_call_cnt if we do tail calls.
114 * Otherwise, put in NOPs so that it can be skipped when we are
115 * invoked through a tail call.
117 if (ctx->seen & SEEN_TAILCALL) {
118 PPC_LI(b2p[TMP_REG_1], 0);
119 /* this goes in the redzone */
120 PPC_BPF_STL(b2p[TMP_REG_1], 1, -(BPF_PPC_STACK_SAVE + 8));
126 #define BPF_TAILCALL_PROLOGUE_SIZE 8
128 if (bpf_has_stack_frame(ctx)) {
130 * We need a stack frame, but we don't necessarily need to
131 * save/restore LR unless we call other functions
133 if (ctx->seen & SEEN_FUNC) {
134 EMIT(PPC_INST_MFLR | __PPC_RT(R0));
135 PPC_BPF_STL(0, 1, PPC_LR_STKOFF);
138 PPC_BPF_STLU(1, 1, -(BPF_PPC_STACKFRAME + ctx->stack_size));
142 * Back up non-volatile regs -- BPF registers 6-10
143 * If we haven't created our own stack frame, we save these
144 * in the protected zone below the previous stack frame
146 for (i = BPF_REG_6; i <= BPF_REG_10; i++)
147 if (bpf_is_seen_register(ctx, i))
148 PPC_BPF_STL(b2p[i], 1, bpf_jit_stack_offsetof(ctx, b2p[i]));
151 * Save additional non-volatile regs if we cache skb
152 * Also, setup skb data
154 if (ctx->seen & SEEN_SKB) {
155 PPC_BPF_STL(b2p[SKB_HLEN_REG], 1,
156 bpf_jit_stack_offsetof(ctx, b2p[SKB_HLEN_REG]));
157 PPC_BPF_STL(b2p[SKB_DATA_REG], 1,
158 bpf_jit_stack_offsetof(ctx, b2p[SKB_DATA_REG]));
159 bpf_jit_emit_skb_loads(image, ctx);
162 /* Setup frame pointer to point to the bpf stack area */
163 if (bpf_is_seen_register(ctx, BPF_REG_FP))
164 PPC_ADDI(b2p[BPF_REG_FP], 1,
165 STACK_FRAME_MIN_SIZE + ctx->stack_size);
168 static void bpf_jit_emit_common_epilogue(u32 *image, struct codegen_context *ctx)
173 for (i = BPF_REG_6; i <= BPF_REG_10; i++)
174 if (bpf_is_seen_register(ctx, i))
175 PPC_BPF_LL(b2p[i], 1, bpf_jit_stack_offsetof(ctx, b2p[i]));
177 /* Restore non-volatile registers used for skb cache */
178 if (ctx->seen & SEEN_SKB) {
179 PPC_BPF_LL(b2p[SKB_HLEN_REG], 1,
180 bpf_jit_stack_offsetof(ctx, b2p[SKB_HLEN_REG]));
181 PPC_BPF_LL(b2p[SKB_DATA_REG], 1,
182 bpf_jit_stack_offsetof(ctx, b2p[SKB_DATA_REG]));
185 /* Tear down our stack frame */
186 if (bpf_has_stack_frame(ctx)) {
187 PPC_ADDI(1, 1, BPF_PPC_STACKFRAME + ctx->stack_size);
188 if (ctx->seen & SEEN_FUNC) {
189 PPC_BPF_LL(0, 1, PPC_LR_STKOFF);
195 static void bpf_jit_build_epilogue(u32 *image, struct codegen_context *ctx)
197 bpf_jit_emit_common_epilogue(image, ctx);
199 /* Move result to r3 */
200 PPC_MR(3, b2p[BPF_REG_0]);
205 static void bpf_jit_emit_func_call(u32 *image, struct codegen_context *ctx, u64 func)
207 #ifdef PPC64_ELF_ABI_v1
208 /* func points to the function descriptor */
209 PPC_LI64(b2p[TMP_REG_2], func);
210 /* Load actual entry point from function descriptor */
211 PPC_BPF_LL(b2p[TMP_REG_1], b2p[TMP_REG_2], 0);
212 /* ... and move it to LR */
213 PPC_MTLR(b2p[TMP_REG_1]);
215 * Load TOC from function descriptor at offset 8.
216 * We can clobber r2 since we get called through a
217 * function pointer (so caller will save/restore r2)
218 * and since we don't use a TOC ourself.
220 PPC_BPF_LL(2, b2p[TMP_REG_2], 8);
222 /* We can clobber r12 */
223 PPC_FUNC_ADDR(12, func);
229 static void bpf_jit_emit_tail_call(u32 *image, struct codegen_context *ctx, u32 out)
232 * By now, the eBPF program has already setup parameters in r3, r4 and r5
233 * r3/BPF_REG_1 - pointer to ctx -- passed as is to the next bpf program
234 * r4/BPF_REG_2 - pointer to bpf_array
235 * r5/BPF_REG_3 - index in bpf_array
237 int b2p_bpf_array = b2p[BPF_REG_2];
238 int b2p_index = b2p[BPF_REG_3];
241 * if (index >= array->map.max_entries)
244 PPC_LWZ(b2p[TMP_REG_1], b2p_bpf_array, offsetof(struct bpf_array, map.max_entries));
245 PPC_CMPLW(b2p_index, b2p[TMP_REG_1]);
246 PPC_BCC(COND_GE, out);
249 * if (tail_call_cnt > MAX_TAIL_CALL_CNT)
252 PPC_LD(b2p[TMP_REG_1], 1, bpf_jit_stack_tailcallcnt(ctx));
253 PPC_CMPLWI(b2p[TMP_REG_1], MAX_TAIL_CALL_CNT);
254 PPC_BCC(COND_GT, out);
259 PPC_ADDI(b2p[TMP_REG_1], b2p[TMP_REG_1], 1);
260 PPC_BPF_STL(b2p[TMP_REG_1], 1, bpf_jit_stack_tailcallcnt(ctx));
262 /* prog = array->ptrs[index]; */
263 PPC_MULI(b2p[TMP_REG_1], b2p_index, 8);
264 PPC_ADD(b2p[TMP_REG_1], b2p[TMP_REG_1], b2p_bpf_array);
265 PPC_LD(b2p[TMP_REG_1], b2p[TMP_REG_1], offsetof(struct bpf_array, ptrs));
271 PPC_CMPLDI(b2p[TMP_REG_1], 0);
272 PPC_BCC(COND_EQ, out);
274 /* goto *(prog->bpf_func + prologue_size); */
275 PPC_LD(b2p[TMP_REG_1], b2p[TMP_REG_1], offsetof(struct bpf_prog, bpf_func));
276 #ifdef PPC64_ELF_ABI_v1
277 /* skip past the function descriptor */
278 PPC_ADDI(b2p[TMP_REG_1], b2p[TMP_REG_1],
279 FUNCTION_DESCR_SIZE + BPF_TAILCALL_PROLOGUE_SIZE);
281 PPC_ADDI(b2p[TMP_REG_1], b2p[TMP_REG_1], BPF_TAILCALL_PROLOGUE_SIZE);
283 PPC_MTCTR(b2p[TMP_REG_1]);
285 /* tear down stack, restore NVRs, ... */
286 bpf_jit_emit_common_epilogue(image, ctx);
292 /* Assemble the body code between the prologue & epilogue */
293 static int bpf_jit_build_body(struct bpf_prog *fp, u32 *image,
294 struct codegen_context *ctx,
297 const struct bpf_insn *insn = fp->insnsi;
301 /* Start of epilogue code - will only be valid 2nd pass onwards */
302 u32 exit_addr = addrs[flen];
304 for (i = 0; i < flen; i++) {
305 u32 code = insn[i].code;
306 u32 dst_reg = b2p[insn[i].dst_reg];
307 u32 src_reg = b2p[insn[i].src_reg];
308 s16 off = insn[i].off;
309 s32 imm = insn[i].imm;
315 * addrs[] maps a BPF bytecode address into a real offset from
316 * the start of the body code.
318 addrs[i] = ctx->idx * 4;
321 * As an optimization, we note down which non-volatile registers
322 * are used so that we can only save/restore those in our
323 * prologue and epilogue. We do this here regardless of whether
324 * the actual BPF instruction uses src/dst registers or not
325 * (for instance, BPF_CALL does not use them). The expectation
326 * is that those instructions will have src_reg/dst_reg set to
327 * 0. Even otherwise, we just lose some prologue/epilogue
328 * optimization but everything else should work without
331 if (dst_reg >= BPF_PPC_NVR_MIN && dst_reg < 32)
332 bpf_set_seen_register(ctx, insn[i].dst_reg);
333 if (src_reg >= BPF_PPC_NVR_MIN && src_reg < 32)
334 bpf_set_seen_register(ctx, insn[i].src_reg);
338 * Arithmetic operations: ADD/SUB/MUL/DIV/MOD/NEG
340 case BPF_ALU | BPF_ADD | BPF_X: /* (u32) dst += (u32) src */
341 case BPF_ALU64 | BPF_ADD | BPF_X: /* dst += src */
342 PPC_ADD(dst_reg, dst_reg, src_reg);
343 goto bpf_alu32_trunc;
344 case BPF_ALU | BPF_SUB | BPF_X: /* (u32) dst -= (u32) src */
345 case BPF_ALU64 | BPF_SUB | BPF_X: /* dst -= src */
346 PPC_SUB(dst_reg, dst_reg, src_reg);
347 goto bpf_alu32_trunc;
348 case BPF_ALU | BPF_ADD | BPF_K: /* (u32) dst += (u32) imm */
349 case BPF_ALU | BPF_SUB | BPF_K: /* (u32) dst -= (u32) imm */
350 case BPF_ALU64 | BPF_ADD | BPF_K: /* dst += imm */
351 case BPF_ALU64 | BPF_SUB | BPF_K: /* dst -= imm */
352 if (BPF_OP(code) == BPF_SUB)
355 if (imm >= -32768 && imm < 32768)
356 PPC_ADDI(dst_reg, dst_reg, IMM_L(imm));
358 PPC_LI32(b2p[TMP_REG_1], imm);
359 PPC_ADD(dst_reg, dst_reg, b2p[TMP_REG_1]);
362 goto bpf_alu32_trunc;
363 case BPF_ALU | BPF_MUL | BPF_X: /* (u32) dst *= (u32) src */
364 case BPF_ALU64 | BPF_MUL | BPF_X: /* dst *= src */
365 if (BPF_CLASS(code) == BPF_ALU)
366 PPC_MULW(dst_reg, dst_reg, src_reg);
368 PPC_MULD(dst_reg, dst_reg, src_reg);
369 goto bpf_alu32_trunc;
370 case BPF_ALU | BPF_MUL | BPF_K: /* (u32) dst *= (u32) imm */
371 case BPF_ALU64 | BPF_MUL | BPF_K: /* dst *= imm */
372 if (imm >= -32768 && imm < 32768)
373 PPC_MULI(dst_reg, dst_reg, IMM_L(imm));
375 PPC_LI32(b2p[TMP_REG_1], imm);
376 if (BPF_CLASS(code) == BPF_ALU)
377 PPC_MULW(dst_reg, dst_reg,
380 PPC_MULD(dst_reg, dst_reg,
383 goto bpf_alu32_trunc;
384 case BPF_ALU | BPF_DIV | BPF_X: /* (u32) dst /= (u32) src */
385 case BPF_ALU | BPF_MOD | BPF_X: /* (u32) dst %= (u32) src */
386 PPC_CMPWI(src_reg, 0);
387 PPC_BCC_SHORT(COND_NE, (ctx->idx * 4) + 12);
388 PPC_LI(b2p[BPF_REG_0], 0);
390 if (BPF_OP(code) == BPF_MOD) {
391 PPC_DIVWU(b2p[TMP_REG_1], dst_reg, src_reg);
392 PPC_MULW(b2p[TMP_REG_1], src_reg,
394 PPC_SUB(dst_reg, dst_reg, b2p[TMP_REG_1]);
396 PPC_DIVWU(dst_reg, dst_reg, src_reg);
397 goto bpf_alu32_trunc;
398 case BPF_ALU64 | BPF_DIV | BPF_X: /* dst /= src */
399 case BPF_ALU64 | BPF_MOD | BPF_X: /* dst %= src */
400 PPC_CMPDI(src_reg, 0);
401 PPC_BCC_SHORT(COND_NE, (ctx->idx * 4) + 12);
402 PPC_LI(b2p[BPF_REG_0], 0);
404 if (BPF_OP(code) == BPF_MOD) {
405 PPC_DIVD(b2p[TMP_REG_1], dst_reg, src_reg);
406 PPC_MULD(b2p[TMP_REG_1], src_reg,
408 PPC_SUB(dst_reg, dst_reg, b2p[TMP_REG_1]);
410 PPC_DIVD(dst_reg, dst_reg, src_reg);
412 case BPF_ALU | BPF_MOD | BPF_K: /* (u32) dst %= (u32) imm */
413 case BPF_ALU | BPF_DIV | BPF_K: /* (u32) dst /= (u32) imm */
414 case BPF_ALU64 | BPF_MOD | BPF_K: /* dst %= imm */
415 case BPF_ALU64 | BPF_DIV | BPF_K: /* dst /= imm */
419 goto bpf_alu32_trunc;
421 PPC_LI32(b2p[TMP_REG_1], imm);
422 switch (BPF_CLASS(code)) {
424 if (BPF_OP(code) == BPF_MOD) {
425 PPC_DIVWU(b2p[TMP_REG_2], dst_reg,
427 PPC_MULW(b2p[TMP_REG_1],
430 PPC_SUB(dst_reg, dst_reg,
433 PPC_DIVWU(dst_reg, dst_reg,
437 if (BPF_OP(code) == BPF_MOD) {
438 PPC_DIVD(b2p[TMP_REG_2], dst_reg,
440 PPC_MULD(b2p[TMP_REG_1],
443 PPC_SUB(dst_reg, dst_reg,
446 PPC_DIVD(dst_reg, dst_reg,
450 goto bpf_alu32_trunc;
451 case BPF_ALU | BPF_NEG: /* (u32) dst = -dst */
452 case BPF_ALU64 | BPF_NEG: /* dst = -dst */
453 PPC_NEG(dst_reg, dst_reg);
454 goto bpf_alu32_trunc;
457 * Logical operations: AND/OR/XOR/[A]LSH/[A]RSH
459 case BPF_ALU | BPF_AND | BPF_X: /* (u32) dst = dst & src */
460 case BPF_ALU64 | BPF_AND | BPF_X: /* dst = dst & src */
461 PPC_AND(dst_reg, dst_reg, src_reg);
462 goto bpf_alu32_trunc;
463 case BPF_ALU | BPF_AND | BPF_K: /* (u32) dst = dst & imm */
464 case BPF_ALU64 | BPF_AND | BPF_K: /* dst = dst & imm */
466 PPC_ANDI(dst_reg, dst_reg, IMM_L(imm));
469 PPC_LI32(b2p[TMP_REG_1], imm);
470 PPC_AND(dst_reg, dst_reg, b2p[TMP_REG_1]);
472 goto bpf_alu32_trunc;
473 case BPF_ALU | BPF_OR | BPF_X: /* dst = (u32) dst | (u32) src */
474 case BPF_ALU64 | BPF_OR | BPF_X: /* dst = dst | src */
475 PPC_OR(dst_reg, dst_reg, src_reg);
476 goto bpf_alu32_trunc;
477 case BPF_ALU | BPF_OR | BPF_K:/* dst = (u32) dst | (u32) imm */
478 case BPF_ALU64 | BPF_OR | BPF_K:/* dst = dst | imm */
479 if (imm < 0 && BPF_CLASS(code) == BPF_ALU64) {
481 PPC_LI32(b2p[TMP_REG_1], imm);
482 PPC_OR(dst_reg, dst_reg, b2p[TMP_REG_1]);
485 PPC_ORI(dst_reg, dst_reg, IMM_L(imm));
487 PPC_ORIS(dst_reg, dst_reg, IMM_H(imm));
489 goto bpf_alu32_trunc;
490 case BPF_ALU | BPF_XOR | BPF_X: /* (u32) dst ^= src */
491 case BPF_ALU64 | BPF_XOR | BPF_X: /* dst ^= src */
492 PPC_XOR(dst_reg, dst_reg, src_reg);
493 goto bpf_alu32_trunc;
494 case BPF_ALU | BPF_XOR | BPF_K: /* (u32) dst ^= (u32) imm */
495 case BPF_ALU64 | BPF_XOR | BPF_K: /* dst ^= imm */
496 if (imm < 0 && BPF_CLASS(code) == BPF_ALU64) {
498 PPC_LI32(b2p[TMP_REG_1], imm);
499 PPC_XOR(dst_reg, dst_reg, b2p[TMP_REG_1]);
502 PPC_XORI(dst_reg, dst_reg, IMM_L(imm));
504 PPC_XORIS(dst_reg, dst_reg, IMM_H(imm));
506 goto bpf_alu32_trunc;
507 case BPF_ALU | BPF_LSH | BPF_X: /* (u32) dst <<= (u32) src */
508 /* slw clears top 32 bits */
509 PPC_SLW(dst_reg, dst_reg, src_reg);
511 case BPF_ALU64 | BPF_LSH | BPF_X: /* dst <<= src; */
512 PPC_SLD(dst_reg, dst_reg, src_reg);
514 case BPF_ALU | BPF_LSH | BPF_K: /* (u32) dst <<== (u32) imm */
515 /* with imm 0, we still need to clear top 32 bits */
516 PPC_SLWI(dst_reg, dst_reg, imm);
518 case BPF_ALU64 | BPF_LSH | BPF_K: /* dst <<== imm */
520 PPC_SLDI(dst_reg, dst_reg, imm);
522 case BPF_ALU | BPF_RSH | BPF_X: /* (u32) dst >>= (u32) src */
523 PPC_SRW(dst_reg, dst_reg, src_reg);
525 case BPF_ALU64 | BPF_RSH | BPF_X: /* dst >>= src */
526 PPC_SRD(dst_reg, dst_reg, src_reg);
528 case BPF_ALU | BPF_RSH | BPF_K: /* (u32) dst >>= (u32) imm */
529 PPC_SRWI(dst_reg, dst_reg, imm);
531 case BPF_ALU64 | BPF_RSH | BPF_K: /* dst >>= imm */
533 PPC_SRDI(dst_reg, dst_reg, imm);
535 case BPF_ALU64 | BPF_ARSH | BPF_X: /* (s64) dst >>= src */
536 PPC_SRAD(dst_reg, dst_reg, src_reg);
538 case BPF_ALU64 | BPF_ARSH | BPF_K: /* (s64) dst >>= imm */
540 PPC_SRADI(dst_reg, dst_reg, imm);
546 case BPF_ALU | BPF_MOV | BPF_X: /* (u32) dst = src */
547 case BPF_ALU64 | BPF_MOV | BPF_X: /* dst = src */
548 PPC_MR(dst_reg, src_reg);
549 goto bpf_alu32_trunc;
550 case BPF_ALU | BPF_MOV | BPF_K: /* (u32) dst = imm */
551 case BPF_ALU64 | BPF_MOV | BPF_K: /* dst = (s64) imm */
552 PPC_LI32(dst_reg, imm);
554 goto bpf_alu32_trunc;
558 /* Truncate to 32-bits */
559 if (BPF_CLASS(code) == BPF_ALU)
560 PPC_RLWINM(dst_reg, dst_reg, 0, 0, 31);
566 case BPF_ALU | BPF_END | BPF_FROM_LE:
567 case BPF_ALU | BPF_END | BPF_FROM_BE:
568 #ifdef __BIG_ENDIAN__
569 if (BPF_SRC(code) == BPF_FROM_BE)
571 #else /* !__BIG_ENDIAN__ */
572 if (BPF_SRC(code) == BPF_FROM_LE)
577 /* Rotate 8 bits left & mask with 0x0000ff00 */
578 PPC_RLWINM(b2p[TMP_REG_1], dst_reg, 8, 16, 23);
579 /* Rotate 8 bits right & insert LSB to reg */
580 PPC_RLWIMI(b2p[TMP_REG_1], dst_reg, 24, 24, 31);
581 /* Move result back to dst_reg */
582 PPC_MR(dst_reg, b2p[TMP_REG_1]);
586 * Rotate word left by 8 bits:
587 * 2 bytes are already in their final position
588 * -- byte 2 and 4 (of bytes 1, 2, 3 and 4)
590 PPC_RLWINM(b2p[TMP_REG_1], dst_reg, 8, 0, 31);
591 /* Rotate 24 bits and insert byte 1 */
592 PPC_RLWIMI(b2p[TMP_REG_1], dst_reg, 24, 0, 7);
593 /* Rotate 24 bits and insert byte 3 */
594 PPC_RLWIMI(b2p[TMP_REG_1], dst_reg, 24, 16, 23);
595 PPC_MR(dst_reg, b2p[TMP_REG_1]);
599 * Way easier and faster(?) to store the value
600 * into stack and then use ldbrx
602 * ctx->seen will be reliable in pass2, but
603 * the instructions generated will remain the
604 * same across all passes
606 PPC_STD(dst_reg, 1, bpf_jit_stack_local(ctx));
607 PPC_ADDI(b2p[TMP_REG_1], 1, bpf_jit_stack_local(ctx));
608 PPC_LDBRX(dst_reg, 0, b2p[TMP_REG_1]);
616 /* zero-extend 16 bits into 64 bits */
617 PPC_RLDICL(dst_reg, dst_reg, 0, 48);
620 /* zero-extend 32 bits into 64 bits */
621 PPC_RLDICL(dst_reg, dst_reg, 0, 32);
632 case BPF_STX | BPF_MEM | BPF_B: /* *(u8 *)(dst + off) = src */
633 case BPF_ST | BPF_MEM | BPF_B: /* *(u8 *)(dst + off) = imm */
634 if (BPF_CLASS(code) == BPF_ST) {
635 PPC_LI(b2p[TMP_REG_1], imm);
636 src_reg = b2p[TMP_REG_1];
638 PPC_STB(src_reg, dst_reg, off);
640 case BPF_STX | BPF_MEM | BPF_H: /* (u16 *)(dst + off) = src */
641 case BPF_ST | BPF_MEM | BPF_H: /* (u16 *)(dst + off) = imm */
642 if (BPF_CLASS(code) == BPF_ST) {
643 PPC_LI(b2p[TMP_REG_1], imm);
644 src_reg = b2p[TMP_REG_1];
646 PPC_STH(src_reg, dst_reg, off);
648 case BPF_STX | BPF_MEM | BPF_W: /* *(u32 *)(dst + off) = src */
649 case BPF_ST | BPF_MEM | BPF_W: /* *(u32 *)(dst + off) = imm */
650 if (BPF_CLASS(code) == BPF_ST) {
651 PPC_LI32(b2p[TMP_REG_1], imm);
652 src_reg = b2p[TMP_REG_1];
654 PPC_STW(src_reg, dst_reg, off);
656 case BPF_STX | BPF_MEM | BPF_DW: /* (u64 *)(dst + off) = src */
657 case BPF_ST | BPF_MEM | BPF_DW: /* *(u64 *)(dst + off) = imm */
658 if (BPF_CLASS(code) == BPF_ST) {
659 PPC_LI32(b2p[TMP_REG_1], imm);
660 src_reg = b2p[TMP_REG_1];
662 PPC_STD(src_reg, dst_reg, off);
666 * BPF_STX XADD (atomic_add)
668 /* *(u32 *)(dst + off) += src */
669 case BPF_STX | BPF_XADD | BPF_W:
670 /* Get EA into TMP_REG_1 */
671 PPC_ADDI(b2p[TMP_REG_1], dst_reg, off);
672 /* error if EA is not word-aligned */
673 PPC_ANDI(b2p[TMP_REG_2], b2p[TMP_REG_1], 0x03);
674 PPC_BCC_SHORT(COND_EQ, (ctx->idx * 4) + 12);
675 PPC_LI(b2p[BPF_REG_0], 0);
677 /* load value from memory into TMP_REG_2 */
678 PPC_BPF_LWARX(b2p[TMP_REG_2], 0, b2p[TMP_REG_1], 0);
679 /* add value from src_reg into this */
680 PPC_ADD(b2p[TMP_REG_2], b2p[TMP_REG_2], src_reg);
681 /* store result back */
682 PPC_BPF_STWCX(b2p[TMP_REG_2], 0, b2p[TMP_REG_1]);
683 /* we're done if this succeeded */
684 PPC_BCC_SHORT(COND_EQ, (ctx->idx * 4) + (7*4));
685 /* otherwise, let's try once more */
686 PPC_BPF_LWARX(b2p[TMP_REG_2], 0, b2p[TMP_REG_1], 0);
687 PPC_ADD(b2p[TMP_REG_2], b2p[TMP_REG_2], src_reg);
688 PPC_BPF_STWCX(b2p[TMP_REG_2], 0, b2p[TMP_REG_1]);
689 /* exit if the store was not successful */
690 PPC_LI(b2p[BPF_REG_0], 0);
691 PPC_BCC(COND_NE, exit_addr);
693 /* *(u64 *)(dst + off) += src */
694 case BPF_STX | BPF_XADD | BPF_DW:
695 PPC_ADDI(b2p[TMP_REG_1], dst_reg, off);
696 /* error if EA is not doubleword-aligned */
697 PPC_ANDI(b2p[TMP_REG_2], b2p[TMP_REG_1], 0x07);
698 PPC_BCC_SHORT(COND_EQ, (ctx->idx * 4) + (3*4));
699 PPC_LI(b2p[BPF_REG_0], 0);
701 PPC_BPF_LDARX(b2p[TMP_REG_2], 0, b2p[TMP_REG_1], 0);
702 PPC_ADD(b2p[TMP_REG_2], b2p[TMP_REG_2], src_reg);
703 PPC_BPF_STDCX(b2p[TMP_REG_2], 0, b2p[TMP_REG_1]);
704 PPC_BCC_SHORT(COND_EQ, (ctx->idx * 4) + (7*4));
705 PPC_BPF_LDARX(b2p[TMP_REG_2], 0, b2p[TMP_REG_1], 0);
706 PPC_ADD(b2p[TMP_REG_2], b2p[TMP_REG_2], src_reg);
707 PPC_BPF_STDCX(b2p[TMP_REG_2], 0, b2p[TMP_REG_1]);
708 PPC_LI(b2p[BPF_REG_0], 0);
709 PPC_BCC(COND_NE, exit_addr);
715 /* dst = *(u8 *)(ul) (src + off) */
716 case BPF_LDX | BPF_MEM | BPF_B:
717 PPC_LBZ(dst_reg, src_reg, off);
719 /* dst = *(u16 *)(ul) (src + off) */
720 case BPF_LDX | BPF_MEM | BPF_H:
721 PPC_LHZ(dst_reg, src_reg, off);
723 /* dst = *(u32 *)(ul) (src + off) */
724 case BPF_LDX | BPF_MEM | BPF_W:
725 PPC_LWZ(dst_reg, src_reg, off);
727 /* dst = *(u64 *)(ul) (src + off) */
728 case BPF_LDX | BPF_MEM | BPF_DW:
729 PPC_LD(dst_reg, src_reg, off);
734 * 16 byte instruction that uses two 'struct bpf_insn'
736 case BPF_LD | BPF_IMM | BPF_DW: /* dst = (u64) imm */
737 imm64 = ((u64)(u32) insn[i].imm) |
738 (((u64)(u32) insn[i+1].imm) << 32);
739 /* Adjust for two bpf instructions */
740 addrs[++i] = ctx->idx * 4;
741 PPC_LI64(dst_reg, imm64);
747 case BPF_JMP | BPF_EXIT:
749 * If this isn't the very last instruction, branch to
750 * the epilogue. If we _are_ the last instruction,
751 * we'll just fall through to the epilogue.
755 /* else fall through to the epilogue */
761 case BPF_JMP | BPF_CALL:
762 ctx->seen |= SEEN_FUNC;
763 func = (u8 *) __bpf_call_base + imm;
765 /* Save skb pointer if we need to re-cache skb data */
766 if ((ctx->seen & SEEN_SKB) &&
767 bpf_helper_changes_pkt_data(func))
768 PPC_BPF_STL(3, 1, bpf_jit_stack_local(ctx));
770 bpf_jit_emit_func_call(image, ctx, (u64)func);
772 /* move return value from r3 to BPF_REG_0 */
773 PPC_MR(b2p[BPF_REG_0], 3);
775 /* refresh skb cache */
776 if ((ctx->seen & SEEN_SKB) &&
777 bpf_helper_changes_pkt_data(func)) {
778 /* reload skb pointer to r3 */
779 PPC_BPF_LL(3, 1, bpf_jit_stack_local(ctx));
780 bpf_jit_emit_skb_loads(image, ctx);
787 case BPF_JMP | BPF_JA:
788 PPC_JMP(addrs[i + 1 + off]);
791 case BPF_JMP | BPF_JGT | BPF_K:
792 case BPF_JMP | BPF_JGT | BPF_X:
793 case BPF_JMP | BPF_JSGT | BPF_K:
794 case BPF_JMP | BPF_JSGT | BPF_X:
797 case BPF_JMP | BPF_JLT | BPF_K:
798 case BPF_JMP | BPF_JLT | BPF_X:
799 case BPF_JMP | BPF_JSLT | BPF_K:
800 case BPF_JMP | BPF_JSLT | BPF_X:
803 case BPF_JMP | BPF_JGE | BPF_K:
804 case BPF_JMP | BPF_JGE | BPF_X:
805 case BPF_JMP | BPF_JSGE | BPF_K:
806 case BPF_JMP | BPF_JSGE | BPF_X:
809 case BPF_JMP | BPF_JLE | BPF_K:
810 case BPF_JMP | BPF_JLE | BPF_X:
811 case BPF_JMP | BPF_JSLE | BPF_K:
812 case BPF_JMP | BPF_JSLE | BPF_X:
815 case BPF_JMP | BPF_JEQ | BPF_K:
816 case BPF_JMP | BPF_JEQ | BPF_X:
819 case BPF_JMP | BPF_JNE | BPF_K:
820 case BPF_JMP | BPF_JNE | BPF_X:
823 case BPF_JMP | BPF_JSET | BPF_K:
824 case BPF_JMP | BPF_JSET | BPF_X:
830 case BPF_JMP | BPF_JGT | BPF_X:
831 case BPF_JMP | BPF_JLT | BPF_X:
832 case BPF_JMP | BPF_JGE | BPF_X:
833 case BPF_JMP | BPF_JLE | BPF_X:
834 case BPF_JMP | BPF_JEQ | BPF_X:
835 case BPF_JMP | BPF_JNE | BPF_X:
836 /* unsigned comparison */
837 PPC_CMPLD(dst_reg, src_reg);
839 case BPF_JMP | BPF_JSGT | BPF_X:
840 case BPF_JMP | BPF_JSLT | BPF_X:
841 case BPF_JMP | BPF_JSGE | BPF_X:
842 case BPF_JMP | BPF_JSLE | BPF_X:
843 /* signed comparison */
844 PPC_CMPD(dst_reg, src_reg);
846 case BPF_JMP | BPF_JSET | BPF_X:
847 PPC_AND_DOT(b2p[TMP_REG_1], dst_reg, src_reg);
849 case BPF_JMP | BPF_JNE | BPF_K:
850 case BPF_JMP | BPF_JEQ | BPF_K:
851 case BPF_JMP | BPF_JGT | BPF_K:
852 case BPF_JMP | BPF_JLT | BPF_K:
853 case BPF_JMP | BPF_JGE | BPF_K:
854 case BPF_JMP | BPF_JLE | BPF_K:
856 * Need sign-extended load, so only positive
857 * values can be used as imm in cmpldi
859 if (imm >= 0 && imm < 32768)
860 PPC_CMPLDI(dst_reg, imm);
862 /* sign-extending load */
863 PPC_LI32(b2p[TMP_REG_1], imm);
864 /* ... but unsigned comparison */
865 PPC_CMPLD(dst_reg, b2p[TMP_REG_1]);
868 case BPF_JMP | BPF_JSGT | BPF_K:
869 case BPF_JMP | BPF_JSLT | BPF_K:
870 case BPF_JMP | BPF_JSGE | BPF_K:
871 case BPF_JMP | BPF_JSLE | BPF_K:
873 * signed comparison, so any 16-bit value
874 * can be used in cmpdi
876 if (imm >= -32768 && imm < 32768)
877 PPC_CMPDI(dst_reg, imm);
879 PPC_LI32(b2p[TMP_REG_1], imm);
880 PPC_CMPD(dst_reg, b2p[TMP_REG_1]);
883 case BPF_JMP | BPF_JSET | BPF_K:
884 /* andi does not sign-extend the immediate */
885 if (imm >= 0 && imm < 32768)
886 /* PPC_ANDI is _only/always_ dot-form */
887 PPC_ANDI(b2p[TMP_REG_1], dst_reg, imm);
889 PPC_LI32(b2p[TMP_REG_1], imm);
890 PPC_AND_DOT(b2p[TMP_REG_1], dst_reg,
895 PPC_BCC(true_cond, addrs[i + 1 + off]);
899 * Loads from packet header/data
900 * Assume 32-bit input value in imm and X (src_reg)
904 case BPF_LD | BPF_W | BPF_ABS:
905 func = (u8 *)CHOOSE_LOAD_FUNC(imm, sk_load_word);
906 goto common_load_abs;
907 case BPF_LD | BPF_H | BPF_ABS:
908 func = (u8 *)CHOOSE_LOAD_FUNC(imm, sk_load_half);
909 goto common_load_abs;
910 case BPF_LD | BPF_B | BPF_ABS:
911 func = (u8 *)CHOOSE_LOAD_FUNC(imm, sk_load_byte);
915 * Load into r4, which can just be passed onto
916 * skb load helpers as the second parameter
922 case BPF_LD | BPF_W | BPF_IND:
923 func = (u8 *)sk_load_word;
924 goto common_load_ind;
925 case BPF_LD | BPF_H | BPF_IND:
926 func = (u8 *)sk_load_half;
927 goto common_load_ind;
928 case BPF_LD | BPF_B | BPF_IND:
929 func = (u8 *)sk_load_byte;
932 * Load from [src_reg + imm]
933 * Treat src_reg as a 32-bit value
935 PPC_EXTSW(4, src_reg);
937 if (imm >= -32768 && imm < 32768)
938 PPC_ADDI(4, 4, IMM_L(imm));
940 PPC_LI32(b2p[TMP_REG_1], imm);
941 PPC_ADD(4, 4, b2p[TMP_REG_1]);
946 ctx->seen |= SEEN_SKB;
947 ctx->seen |= SEEN_FUNC;
948 bpf_jit_emit_func_call(image, ctx, (u64)func);
951 * Helper returns 'lt' condition on error, and an
952 * appropriate return value in BPF_REG_0
954 PPC_BCC(COND_LT, exit_addr);
960 case BPF_JMP | BPF_TAIL_CALL:
961 ctx->seen |= SEEN_TAILCALL;
962 bpf_jit_emit_tail_call(image, ctx, addrs[i + 1]);
967 * The filter contains something cruel & unusual.
968 * We don't handle it, but also there shouldn't be
969 * anything missing from our list.
971 pr_err_ratelimited("eBPF filter opcode %04x (@%d) unsupported\n",
977 /* Set end-of-body-code address for exit. */
978 addrs[i] = ctx->idx * 4;
983 struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp)
990 struct codegen_context cgctx;
993 struct bpf_binary_header *bpf_hdr;
994 struct bpf_prog *org_fp = fp;
995 struct bpf_prog *tmp_fp;
996 bool bpf_blinded = false;
1001 tmp_fp = bpf_jit_blind_constants(org_fp);
1005 if (tmp_fp != org_fp) {
1011 addrs = kzalloc((flen+1) * sizeof(*addrs), GFP_KERNEL);
1012 if (addrs == NULL) {
1017 memset(&cgctx, 0, sizeof(struct codegen_context));
1019 /* Make sure that the stack is quadword aligned. */
1020 cgctx.stack_size = round_up(fp->aux->stack_depth, 16);
1022 /* Scouting faux-generate pass 0 */
1023 if (bpf_jit_build_body(fp, 0, &cgctx, addrs)) {
1024 /* We hit something illegal or unsupported. */
1030 * Pretend to build prologue, given the features we've seen. This will
1031 * update ctgtx.idx as it pretends to output instructions, then we can
1032 * calculate total size from idx.
1034 bpf_jit_build_prologue(0, &cgctx);
1035 bpf_jit_build_epilogue(0, &cgctx);
1037 proglen = cgctx.idx * 4;
1038 alloclen = proglen + FUNCTION_DESCR_SIZE;
1040 bpf_hdr = bpf_jit_binary_alloc(alloclen, &image, 4,
1041 bpf_jit_fill_ill_insns);
1047 code_base = (u32 *)(image + FUNCTION_DESCR_SIZE);
1049 /* Code generation passes 1-2 */
1050 for (pass = 1; pass < 3; pass++) {
1051 /* Now build the prologue, body code & epilogue for real. */
1053 bpf_jit_build_prologue(code_base, &cgctx);
1054 bpf_jit_build_body(fp, code_base, &cgctx, addrs);
1055 bpf_jit_build_epilogue(code_base, &cgctx);
1057 if (bpf_jit_enable > 1)
1058 pr_info("Pass %d: shrink = %d, seen = 0x%x\n", pass,
1059 proglen - (cgctx.idx * 4), cgctx.seen);
1062 if (bpf_jit_enable > 1)
1064 * Note that we output the base address of the code_base
1065 * rather than image, since opcodes are in code_base.
1067 bpf_jit_dump(flen, proglen, pass, code_base);
1069 #ifdef PPC64_ELF_ABI_v1
1070 /* Function descriptor nastiness: Address + TOC */
1071 ((u64 *)image)[0] = (u64)code_base;
1072 ((u64 *)image)[1] = local_paca->kernel_toc;
1075 fp->bpf_func = (void *)image;
1077 fp->jited_len = alloclen;
1079 bpf_flush_icache(bpf_hdr, (u8 *)bpf_hdr + (bpf_hdr->pages * PAGE_SIZE));
1085 bpf_jit_prog_release_other(fp, fp == org_fp ? tmp_fp : org_fp);
1090 /* Overriding bpf_jit_free() as we don't set images read-only. */
1091 void bpf_jit_free(struct bpf_prog *fp)
1093 unsigned long addr = (unsigned long)fp->bpf_func & PAGE_MASK;
1094 struct bpf_binary_header *bpf_hdr = (void *)addr;
1097 bpf_jit_binary_free(bpf_hdr);
1099 bpf_prog_unlock_free(fp);