void bpf_jit_compile(struct bpf_prog *fp) { unsigned int cleanup_addr, proglen, oldproglen = 0; u32 temp[8], *prog, *func, seen = 0, pass; const struct sock_filter *filter = fp->insns; int i, flen = fp->len, pc_ret0 = -1; unsigned int *addrs; void *image; if (!bpf_jit_enable) return; addrs = kmalloc_array(flen, sizeof(*addrs), GFP_KERNEL); if (addrs == NULL) return; /* Before first pass, make a rough estimation of addrs[] * each bpf instruction is translated to less than 64 bytes */ for (proglen = 0, i = 0; i < flen; i++) { proglen += 64; addrs[i] = proglen; } cleanup_addr = proglen; /* epilogue address */ image = NULL; for (pass = 0; pass < 10; pass++) { u8 seen_or_pass0 = (pass == 0) ? (SEEN_XREG | SEEN_DATAREF | SEEN_MEM) : seen; /* no prologue/epilogue for trivial filters (RET something) */ proglen = 0; prog = temp; /* Prologue */ if (seen_or_pass0) { if (seen_or_pass0 & SEEN_MEM) { unsigned int sz = BASE_STACKFRAME; sz += BPF_MEMWORDS * sizeof(u32); emit_alloc_stack(sz); } /* Make sure we dont leek kernel memory. */ if (seen_or_pass0 & SEEN_XREG) emit_clear(r_X); /* If this filter needs to access skb data, * load %o4 and %o5 with: * %o4 = skb->len - skb->data_len * %o5 = skb->data * And also back up %o7 into r_saved_O7 so we can * invoke the stubs using 'call'. */ if (seen_or_pass0 & SEEN_DATAREF) { emit_load32(r_SKB, struct sk_buff, len, r_HEADLEN); emit_load32(r_SKB, struct sk_buff, data_len, r_TMP); emit_sub(r_HEADLEN, r_TMP, r_HEADLEN); emit_loadptr(r_SKB, struct sk_buff, data, r_SKB_DATA); } } emit_reg_move(O7, r_saved_O7); /* Make sure we dont leak kernel information to the user. */ if (bpf_needs_clear_a(&filter[0])) emit_clear(r_A); /* A = 0 */ for (i = 0; i < flen; i++) { unsigned int K = filter[i].k; unsigned int t_offset; unsigned int f_offset; u32 t_op, f_op; u16 code = bpf_anc_helper(&filter[i]); int ilen; switch (code) { case BPF_ALU | BPF_ADD | BPF_X: /* A += X; */ emit_alu_X(ADD); break; case BPF_ALU | BPF_ADD | BPF_K: /* A += K; */ emit_alu_K(ADD, K); break; case BPF_ALU | BPF_SUB | BPF_X: /* A -= X; */ emit_alu_X(SUB); break; case BPF_ALU | BPF_SUB | BPF_K: /* A -= K */ emit_alu_K(SUB, K); break; case BPF_ALU | BPF_AND | BPF_X: /* A &= X */ emit_alu_X(AND); break; case BPF_ALU | BPF_AND | BPF_K: /* A &= K */ emit_alu_K(AND, K); break; case BPF_ALU | BPF_OR | BPF_X: /* A |= X */ emit_alu_X(OR); break; case BPF_ALU | BPF_OR | BPF_K: /* A |= K */ emit_alu_K(OR, K); break; case BPF_ANC | SKF_AD_ALU_XOR_X: /* A ^= X; */ case BPF_ALU | BPF_XOR | BPF_X: emit_alu_X(XOR); break; case BPF_ALU | BPF_XOR | BPF_K: /* A ^= K */ emit_alu_K(XOR, K); break; case BPF_ALU | BPF_LSH | BPF_X: /* A <<= X */ emit_alu_X(SLL); break; case BPF_ALU | BPF_LSH | BPF_K: /* A <<= K */ emit_alu_K(SLL, K); break; case BPF_ALU | BPF_RSH | BPF_X: /* A >>= X */ emit_alu_X(SRL); break; case BPF_ALU | BPF_RSH | BPF_K: /* A >>= K */ emit_alu_K(SRL, K); break; case BPF_ALU | BPF_MUL | BPF_X: /* A *= X; */ emit_alu_X(MUL); break; case BPF_ALU | BPF_MUL | BPF_K: /* A *= K */ emit_alu_K(MUL, K); break; case BPF_ALU | BPF_DIV | BPF_K: /* A /= K with K != 0*/ if (K == 1) break; emit_write_y(G0); /* The Sparc v8 architecture requires * three instructions between a %y * register write and the first use. */ emit_nop(); emit_nop(); emit_nop(); emit_alu_K(DIV, K); break; case BPF_ALU | BPF_DIV | BPF_X: /* A /= X; */ emit_cmpi(r_X, 0); if (pc_ret0 > 0) { t_offset = addrs[pc_ret0 - 1]; emit_branch(BE, t_offset + 20); emit_nop(); /* delay slot */ } else { emit_branch_off(BNE, 16); emit_nop(); emit_jump(cleanup_addr + 20); emit_clear(r_A); } emit_write_y(G0); /* The Sparc v8 architecture requires * three instructions between a %y * register write and the first use. */ emit_nop(); emit_nop(); emit_nop(); emit_alu_X(DIV); break; case BPF_ALU | BPF_NEG: emit_neg(); break; case BPF_RET | BPF_K: if (!K) { if (pc_ret0 == -1) pc_ret0 = i; emit_clear(r_A); } else { emit_loadimm(K, r_A); } /* Fallthrough */ case BPF_RET | BPF_A: if (seen_or_pass0) { if (i != flen - 1) { emit_jump(cleanup_addr); emit_nop(); break; } if (seen_or_pass0 & SEEN_MEM) { unsigned int sz = BASE_STACKFRAME; sz += BPF_MEMWORDS * sizeof(u32); emit_release_stack(sz); } } /* jmpl %r_saved_O7 + 8, %g0 */ emit_jmpl(r_saved_O7, 8, G0); emit_reg_move(r_A, O0); /* delay slot */ break; case BPF_MISC | BPF_TAX: seen |= SEEN_XREG; emit_reg_move(r_A, r_X); break; case BPF_MISC | BPF_TXA: seen |= SEEN_XREG; emit_reg_move(r_X, r_A); break; case BPF_ANC | SKF_AD_CPU: emit_load_cpu(r_A); break; case BPF_ANC | SKF_AD_PROTOCOL: emit_skb_load16(protocol, r_A); break; case BPF_ANC | SKF_AD_PKTTYPE: __emit_skb_load8(__pkt_type_offset, r_A); emit_andi(r_A, PKT_TYPE_MAX, r_A); emit_alu_K(SRL, 5); break; case BPF_ANC | SKF_AD_IFINDEX: emit_skb_loadptr(dev, r_A); emit_cmpi(r_A, 0); emit_branch(BE_PTR, cleanup_addr + 4); emit_nop(); emit_load32(r_A, struct net_device, ifindex, r_A); break; case BPF_ANC | SKF_AD_MARK: emit_skb_load32(mark, r_A); break; case BPF_ANC | SKF_AD_QUEUE: emit_skb_load16(queue_mapping, r_A); break; case BPF_ANC | SKF_AD_HATYPE: emit_skb_loadptr(dev, r_A); emit_cmpi(r_A, 0); emit_branch(BE_PTR, cleanup_addr + 4); emit_nop(); emit_load16(r_A, struct net_device, type, r_A); break; case BPF_ANC | SKF_AD_RXHASH: emit_skb_load32(hash, r_A); break; case BPF_ANC | SKF_AD_VLAN_TAG: emit_skb_load16(vlan_tci, r_A); break; case BPF_ANC | SKF_AD_VLAN_TAG_PRESENT: __emit_skb_load8(__pkt_vlan_present_offset, r_A); if (PKT_VLAN_PRESENT_BIT) emit_alu_K(SRL, PKT_VLAN_PRESENT_BIT); if (PKT_VLAN_PRESENT_BIT < 7) emit_andi(r_A, 1, r_A); break; case BPF_LD | BPF_W | BPF_LEN: emit_skb_load32(len, r_A); break; case BPF_LDX | BPF_W | BPF_LEN: emit_skb_load32(len, r_X); break; case BPF_LD | BPF_IMM: emit_loadimm(K, r_A); break; case BPF_LDX | BPF_IMM: emit_loadimm(K, r_X); break; case BPF_LD | BPF_MEM: seen |= SEEN_MEM; emit_ldmem(K * 4, r_A); break; case BPF_LDX | BPF_MEM: seen |= SEEN_MEM | SEEN_XREG; emit_ldmem(K * 4, r_X); break; case BPF_ST: seen |= SEEN_MEM; emit_stmem(K * 4, r_A); break; case BPF_STX: seen |= SEEN_MEM | SEEN_XREG; emit_stmem(K * 4, r_X); break; #define CHOOSE_LOAD_FUNC(K, func) \ ((int)K < 0 ? ((int)K >= SKF_LL_OFF ? func##_negative_offset : func) : func##_positive_offset) case BPF_LD | BPF_W | BPF_ABS: func = CHOOSE_LOAD_FUNC(K, bpf_jit_load_word); common_load: seen |= SEEN_DATAREF; emit_loadimm(K, r_OFF); emit_call(func); break; case BPF_LD | BPF_H | BPF_ABS: func = CHOOSE_LOAD_FUNC(K, bpf_jit_load_half); goto common_load; case BPF_LD | BPF_B | BPF_ABS: func = CHOOSE_LOAD_FUNC(K, bpf_jit_load_byte); goto common_load; case BPF_LDX | BPF_B | BPF_MSH: func = CHOOSE_LOAD_FUNC(K, bpf_jit_load_byte_msh); goto common_load; case BPF_LD | BPF_W | BPF_IND: func = bpf_jit_load_word; common_load_ind: seen |= SEEN_DATAREF | SEEN_XREG; if (K) { if (is_simm13(K)) { emit_addi(r_X, K, r_OFF); } else { emit_loadimm(K, r_TMP); emit_add(r_X, r_TMP, r_OFF); } } else { emit_reg_move(r_X, r_OFF); } emit_call(func); break; case BPF_LD | BPF_H | BPF_IND: func = bpf_jit_load_half; goto common_load_ind; case BPF_LD | BPF_B | BPF_IND: func = bpf_jit_load_byte; goto common_load_ind; case BPF_JMP | BPF_JA: emit_jump(addrs[i + K]); emit_nop(); break; #define COND_SEL(CODE, TOP, FOP) \ case CODE: \ t_op = TOP; \ f_op = FOP; \ goto cond_branch COND_SEL(BPF_JMP | BPF_JGT | BPF_K, BGU, BLEU); COND_SEL(BPF_JMP | BPF_JGE | BPF_K, BGEU, BLU); COND_SEL(BPF_JMP | BPF_JEQ | BPF_K, BE, BNE); COND_SEL(BPF_JMP | BPF_JSET | BPF_K, BNE, BE); COND_SEL(BPF_JMP | BPF_JGT | BPF_X, BGU, BLEU); COND_SEL(BPF_JMP | BPF_JGE | BPF_X, BGEU, BLU); COND_SEL(BPF_JMP | BPF_JEQ | BPF_X, BE, BNE); COND_SEL(BPF_JMP | BPF_JSET | BPF_X, BNE, BE); cond_branch: f_offset = addrs[i + filter[i].jf]; t_offset = addrs[i + filter[i].jt]; /* same targets, can avoid doing the test :) */ if (filter[i].jt == filter[i].jf) { emit_jump(t_offset); emit_nop(); break; } switch (code) { case BPF_JMP | BPF_JGT | BPF_X: case BPF_JMP | BPF_JGE | BPF_X: case BPF_JMP | BPF_JEQ | BPF_X: seen |= SEEN_XREG; emit_cmp(r_A, r_X); break; case BPF_JMP | BPF_JSET | BPF_X: seen |= SEEN_XREG; emit_btst(r_A, r_X); break; case BPF_JMP | BPF_JEQ | BPF_K: case BPF_JMP | BPF_JGT | BPF_K: case BPF_JMP | BPF_JGE | BPF_K: if (is_simm13(K)) { emit_cmpi(r_A, K); } else { emit_loadimm(K, r_TMP); emit_cmp(r_A, r_TMP); } break; case BPF_JMP | BPF_JSET | BPF_K: if (is_simm13(K)) { emit_btsti(r_A, K); } else { emit_loadimm(K, r_TMP); emit_btst(r_A, r_TMP); } break; } if (filter[i].jt != 0) { if (filter[i].jf) t_offset += 8; emit_branch(t_op, t_offset); emit_nop(); /* delay slot */ if (filter[i].jf) { emit_jump(f_offset); emit_nop(); } break; } emit_branch(f_op, f_offset); emit_nop(); /* delay slot */ break; default: /* hmm, too complex filter, give up with jit compiler */ goto out; } ilen = (void *) prog - (void *) temp; if (image) { if (unlikely(proglen + ilen > oldproglen)) { pr_err("bpb_jit_compile fatal error\n"); kfree(addrs); module_memfree(image); return; } memcpy(image + proglen, temp, ilen); } proglen += ilen; addrs[i] = proglen; prog = temp; } /* last bpf instruction is always a RET : * use it to give the cleanup instruction(s) addr */ cleanup_addr = proglen - 8; /* jmpl; mov r_A,%o0; */ if (seen_or_pass0 & SEEN_MEM) cleanup_addr -= 4; /* add %sp, X, %sp; */ if (image) { if (proglen != oldproglen) pr_err("bpb_jit_compile proglen=%u != oldproglen=%u\n", proglen, oldproglen); break; } if (proglen == oldproglen) { image = module_alloc(proglen); if (!image) goto out; } oldproglen = proglen; } if (bpf_jit_enable > 1) bpf_jit_dump(flen, proglen, pass + 1, image); if (image) { fp->bpf_func = (void *)image; fp->jited = 1; } out: kfree(addrs); return; }
/* Assemble the body code between the prologue & epilogue. */ static int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, struct codegen_context *ctx, unsigned int *addrs) { const struct sock_filter *filter = fp->insns; int flen = fp->len; u8 *func; unsigned int true_cond; int i; /* Start of epilogue code */ unsigned int exit_addr = addrs[flen]; for (i = 0; i < flen; i++) { unsigned int K = filter[i].k; u16 code = bpf_anc_helper(&filter[i]); /* * addrs[] maps a BPF bytecode address into a real offset from * the start of the body code. */ addrs[i] = ctx->idx * 4; switch (code) { /*** ALU ops ***/ case BPF_ALU | BPF_ADD | BPF_X: /* A += X; */ ctx->seen |= SEEN_XREG; PPC_ADD(r_A, r_A, r_X); break; case BPF_ALU | BPF_ADD | BPF_K: /* A += K; */ if (!K) break; PPC_ADDI(r_A, r_A, IMM_L(K)); if (K >= 32768) PPC_ADDIS(r_A, r_A, IMM_HA(K)); break; case BPF_ALU | BPF_SUB | BPF_X: /* A -= X; */ ctx->seen |= SEEN_XREG; PPC_SUB(r_A, r_A, r_X); break; case BPF_ALU | BPF_SUB | BPF_K: /* A -= K */ if (!K) break; PPC_ADDI(r_A, r_A, IMM_L(-K)); if (K >= 32768) PPC_ADDIS(r_A, r_A, IMM_HA(-K)); break; case BPF_ALU | BPF_MUL | BPF_X: /* A *= X; */ ctx->seen |= SEEN_XREG; PPC_MUL(r_A, r_A, r_X); break; case BPF_ALU | BPF_MUL | BPF_K: /* A *= K */ if (K < 32768) PPC_MULI(r_A, r_A, K); else { PPC_LI32(r_scratch1, K); PPC_MUL(r_A, r_A, r_scratch1); } break; case BPF_ALU | BPF_MOD | BPF_X: /* A %= X; */ ctx->seen |= SEEN_XREG; PPC_CMPWI(r_X, 0); if (ctx->pc_ret0 != -1) { PPC_BCC(COND_EQ, addrs[ctx->pc_ret0]); } else { PPC_BCC_SHORT(COND_NE, (ctx->idx*4)+12); PPC_LI(r_ret, 0); PPC_JMP(exit_addr); } PPC_DIVWU(r_scratch1, r_A, r_X); PPC_MUL(r_scratch1, r_X, r_scratch1); PPC_SUB(r_A, r_A, r_scratch1); break; case BPF_ALU | BPF_MOD | BPF_K: /* A %= K; */ PPC_LI32(r_scratch2, K); PPC_DIVWU(r_scratch1, r_A, r_scratch2); PPC_MUL(r_scratch1, r_scratch2, r_scratch1); PPC_SUB(r_A, r_A, r_scratch1); break; case BPF_ALU | BPF_DIV | BPF_X: /* A /= X; */ ctx->seen |= SEEN_XREG; PPC_CMPWI(r_X, 0); if (ctx->pc_ret0 != -1) { PPC_BCC(COND_EQ, addrs[ctx->pc_ret0]); } else { /* * Exit, returning 0; first pass hits here * (longer worst-case code size). */ PPC_BCC_SHORT(COND_NE, (ctx->idx*4)+12); PPC_LI(r_ret, 0); PPC_JMP(exit_addr); } PPC_DIVWU(r_A, r_A, r_X); break; case BPF_ALU | BPF_DIV | BPF_K: /* A /= K */ if (K == 1) break; PPC_LI32(r_scratch1, K); PPC_DIVWU(r_A, r_A, r_scratch1); break; case BPF_ALU | BPF_AND | BPF_X: ctx->seen |= SEEN_XREG; PPC_AND(r_A, r_A, r_X); break; case BPF_ALU | BPF_AND | BPF_K: if (!IMM_H(K)) PPC_ANDI(r_A, r_A, K); else { PPC_LI32(r_scratch1, K); PPC_AND(r_A, r_A, r_scratch1); } break; case BPF_ALU | BPF_OR | BPF_X: ctx->seen |= SEEN_XREG; PPC_OR(r_A, r_A, r_X); break; case BPF_ALU | BPF_OR | BPF_K: if (IMM_L(K)) PPC_ORI(r_A, r_A, IMM_L(K)); if (K >= 65536) PPC_ORIS(r_A, r_A, IMM_H(K)); break; case BPF_ANC | SKF_AD_ALU_XOR_X: case BPF_ALU | BPF_XOR | BPF_X: /* A ^= X */ ctx->seen |= SEEN_XREG; PPC_XOR(r_A, r_A, r_X); break; case BPF_ALU | BPF_XOR | BPF_K: /* A ^= K */ if (IMM_L(K)) PPC_XORI(r_A, r_A, IMM_L(K)); if (K >= 65536) PPC_XORIS(r_A, r_A, IMM_H(K)); break; case BPF_ALU | BPF_LSH | BPF_X: /* A <<= X; */ ctx->seen |= SEEN_XREG; PPC_SLW(r_A, r_A, r_X); break; case BPF_ALU | BPF_LSH | BPF_K: if (K == 0) break; else PPC_SLWI(r_A, r_A, K); break; case BPF_ALU | BPF_RSH | BPF_X: /* A >>= X; */ ctx->seen |= SEEN_XREG; PPC_SRW(r_A, r_A, r_X); break; case BPF_ALU | BPF_RSH | BPF_K: /* A >>= K; */ if (K == 0) break; else PPC_SRWI(r_A, r_A, K); break; case BPF_ALU | BPF_NEG: PPC_NEG(r_A, r_A); break; case BPF_RET | BPF_K: PPC_LI32(r_ret, K); if (!K) { if (ctx->pc_ret0 == -1) ctx->pc_ret0 = i; } /* * If this isn't the very last instruction, branch to * the epilogue if we've stuff to clean up. Otherwise, * if there's nothing to tidy, just return. If we /are/ * the last instruction, we're about to fall through to * the epilogue to return. */ if (i != flen - 1) { /* * Note: 'seen' is properly valid only on pass * #2. Both parts of this conditional are the * same instruction size though, meaning the * first pass will still correctly determine the * code size/addresses. */ if (ctx->seen) PPC_JMP(exit_addr); else PPC_BLR(); } break; case BPF_RET | BPF_A: PPC_MR(r_ret, r_A); if (i != flen - 1) { if (ctx->seen) PPC_JMP(exit_addr); else PPC_BLR(); } break; case BPF_MISC | BPF_TAX: /* X = A */ PPC_MR(r_X, r_A); break; case BPF_MISC | BPF_TXA: /* A = X */ ctx->seen |= SEEN_XREG; PPC_MR(r_A, r_X); break; /*** Constant loads/M[] access ***/ case BPF_LD | BPF_IMM: /* A = K */ PPC_LI32(r_A, K); break; case BPF_LDX | BPF_IMM: /* X = K */ PPC_LI32(r_X, K); break; case BPF_LD | BPF_MEM: /* A = mem[K] */ PPC_MR(r_A, r_M + (K & 0xf)); ctx->seen |= SEEN_MEM | (1<<(K & 0xf)); break; case BPF_LDX | BPF_MEM: /* X = mem[K] */ PPC_MR(r_X, r_M + (K & 0xf)); ctx->seen |= SEEN_MEM | (1<<(K & 0xf)); break; case BPF_ST: /* mem[K] = A */ PPC_MR(r_M + (K & 0xf), r_A); ctx->seen |= SEEN_MEM | (1<<(K & 0xf)); break; case BPF_STX: /* mem[K] = X */ PPC_MR(r_M + (K & 0xf), r_X); ctx->seen |= SEEN_XREG | SEEN_MEM | (1<<(K & 0xf)); break; case BPF_LD | BPF_W | BPF_LEN: /* A = skb->len; */ BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, len) != 4); PPC_LWZ_OFFS(r_A, r_skb, offsetof(struct sk_buff, len)); break; case BPF_LDX | BPF_W | BPF_LEN: /* X = skb->len; */ PPC_LWZ_OFFS(r_X, r_skb, offsetof(struct sk_buff, len)); break; /*** Ancillary info loads ***/ case BPF_ANC | SKF_AD_PROTOCOL: /* A = ntohs(skb->protocol); */ BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, protocol) != 2); PPC_NTOHS_OFFS(r_A, r_skb, offsetof(struct sk_buff, protocol)); break; case BPF_ANC | SKF_AD_IFINDEX: PPC_LD_OFFS(r_scratch1, r_skb, offsetof(struct sk_buff, dev)); PPC_CMPDI(r_scratch1, 0); if (ctx->pc_ret0 != -1) { PPC_BCC(COND_EQ, addrs[ctx->pc_ret0]); } else { /* Exit, returning 0; first pass hits here. */ PPC_BCC_SHORT(COND_NE, (ctx->idx*4)+12); PPC_LI(r_ret, 0); PPC_JMP(exit_addr); } BUILD_BUG_ON(FIELD_SIZEOF(struct net_device, ifindex) != 4); PPC_LWZ_OFFS(r_A, r_scratch1, offsetof(struct net_device, ifindex)); break; case BPF_ANC | SKF_AD_MARK: BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, mark) != 4); PPC_LWZ_OFFS(r_A, r_skb, offsetof(struct sk_buff, mark)); break; case BPF_ANC | SKF_AD_RXHASH: BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, hash) != 4); PPC_LWZ_OFFS(r_A, r_skb, offsetof(struct sk_buff, hash)); break; case BPF_ANC | SKF_AD_VLAN_TAG: case BPF_ANC | SKF_AD_VLAN_TAG_PRESENT: BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, vlan_tci) != 2); BUILD_BUG_ON(VLAN_TAG_PRESENT != 0x1000); PPC_LHZ_OFFS(r_A, r_skb, offsetof(struct sk_buff, vlan_tci)); if (code == (BPF_ANC | SKF_AD_VLAN_TAG)) { PPC_ANDI(r_A, r_A, ~VLAN_TAG_PRESENT); } else { PPC_ANDI(r_A, r_A, VLAN_TAG_PRESENT); PPC_SRWI(r_A, r_A, 12); } break; case BPF_ANC | SKF_AD_QUEUE: BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, queue_mapping) != 2); PPC_LHZ_OFFS(r_A, r_skb, offsetof(struct sk_buff, queue_mapping)); break; case BPF_ANC | SKF_AD_CPU: #ifdef CONFIG_SMP /* * PACA ptr is r13: * raw_smp_processor_id() = local_paca->paca_index */ BUILD_BUG_ON(FIELD_SIZEOF(struct paca_struct, paca_index) != 2); PPC_LHZ_OFFS(r_A, 13, offsetof(struct paca_struct, paca_index)); #else PPC_LI(r_A, 0); #endif break; /*** Absolute loads from packet header/data ***/ case BPF_LD | BPF_W | BPF_ABS: func = CHOOSE_LOAD_FUNC(K, sk_load_word); goto common_load; case BPF_LD | BPF_H | BPF_ABS: func = CHOOSE_LOAD_FUNC(K, sk_load_half); goto common_load; case BPF_LD | BPF_B | BPF_ABS: func = CHOOSE_LOAD_FUNC(K, sk_load_byte); common_load: /* Load from [K]. */ ctx->seen |= SEEN_DATAREF; PPC_LI64(r_scratch1, func); PPC_MTLR(r_scratch1); PPC_LI32(r_addr, K); PPC_BLRL(); /* * Helper returns 'lt' condition on error, and an * appropriate return value in r3 */ PPC_BCC(COND_LT, exit_addr); break; /*** Indirect loads from packet header/data ***/ case BPF_LD | BPF_W | BPF_IND: func = sk_load_word; goto common_load_ind; case BPF_LD | BPF_H | BPF_IND: func = sk_load_half; goto common_load_ind; case BPF_LD | BPF_B | BPF_IND: func = sk_load_byte; common_load_ind: /* * Load from [X + K]. Negative offsets are tested for * in the helper functions. */ ctx->seen |= SEEN_DATAREF | SEEN_XREG; PPC_LI64(r_scratch1, func); PPC_MTLR(r_scratch1); PPC_ADDI(r_addr, r_X, IMM_L(K)); if (K >= 32768) PPC_ADDIS(r_addr, r_addr, IMM_HA(K)); PPC_BLRL(); /* If error, cr0.LT set */ PPC_BCC(COND_LT, exit_addr); break; case BPF_LDX | BPF_B | BPF_MSH: func = CHOOSE_LOAD_FUNC(K, sk_load_byte_msh); goto common_load; break; /*** Jump and branches ***/ case BPF_JMP | BPF_JA: if (K != 0) PPC_JMP(addrs[i + 1 + K]); break; case BPF_JMP | BPF_JGT | BPF_K: case BPF_JMP | BPF_JGT | BPF_X: true_cond = COND_GT; goto cond_branch; case BPF_JMP | BPF_JGE | BPF_K: case BPF_JMP | BPF_JGE | BPF_X: true_cond = COND_GE; goto cond_branch; case BPF_JMP | BPF_JEQ | BPF_K: case BPF_JMP | BPF_JEQ | BPF_X: true_cond = COND_EQ; goto cond_branch; case BPF_JMP | BPF_JSET | BPF_K: case BPF_JMP | BPF_JSET | BPF_X: true_cond = COND_NE; /* Fall through */ cond_branch: /* same targets, can avoid doing the test :) */ if (filter[i].jt == filter[i].jf) { if (filter[i].jt > 0) PPC_JMP(addrs[i + 1 + filter[i].jt]); break; } switch (code) { case BPF_JMP | BPF_JGT | BPF_X: case BPF_JMP | BPF_JGE | BPF_X: case BPF_JMP | BPF_JEQ | BPF_X: ctx->seen |= SEEN_XREG; PPC_CMPLW(r_A, r_X); break; case BPF_JMP | BPF_JSET | BPF_X: ctx->seen |= SEEN_XREG; PPC_AND_DOT(r_scratch1, r_A, r_X); break; case BPF_JMP | BPF_JEQ | BPF_K: case BPF_JMP | BPF_JGT | BPF_K: case BPF_JMP | BPF_JGE | BPF_K: if (K < 32768) PPC_CMPLWI(r_A, K); else { PPC_LI32(r_scratch1, K); PPC_CMPLW(r_A, r_scratch1); } break; case BPF_JMP | BPF_JSET | BPF_K: if (K < 32768) /* PPC_ANDI is /only/ dot-form */ PPC_ANDI(r_scratch1, r_A, K); else { PPC_LI32(r_scratch1, K); PPC_AND_DOT(r_scratch1, r_A, r_scratch1); } break; } /* Sometimes branches are constructed "backward", with * the false path being the branch and true path being * a fallthrough to the next instruction. */ if (filter[i].jt == 0) /* Swap the sense of the branch */ PPC_BCC(true_cond ^ COND_CMP_TRUE, addrs[i + 1 + filter[i].jf]); else { PPC_BCC(true_cond, addrs[i + 1 + filter[i].jt]); if (filter[i].jf != 0) PPC_JMP(addrs[i + 1 + filter[i].jf]); } break; default: /* The filter contains something cruel & unusual. * We don't handle it, but also there shouldn't be * anything missing from our list. */ if (printk_ratelimit()) pr_err("BPF filter opcode %04x (@%d) unsupported\n", filter[i].code, i); return -ENOTSUPP; } } /* Set end-of-body-code address for exit. */ addrs[i] = ctx->idx * 4; return 0; }