| /* |
| * BPF Jit compiler for s390. |
| * |
| * Copyright IBM Corp. 2012 |
| * |
| * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com> |
| */ |
| #include <linux/moduleloader.h> |
| #include <linux/netdevice.h> |
| #include <linux/if_vlan.h> |
| #include <linux/filter.h> |
| #include <asm/cacheflush.h> |
| #include <asm/processor.h> |
| #include <asm/facility.h> |
| |
| /* |
| * Conventions: |
| * %r2 = skb pointer |
| * %r3 = offset parameter |
| * %r4 = scratch register / length parameter |
| * %r5 = BPF A accumulator |
| * %r8 = return address |
| * %r9 = save register for skb pointer |
| * %r10 = skb->data |
| * %r11 = skb->len - skb->data_len (headlen) |
| * %r12 = BPF X accumulator |
| * %r13 = literal pool pointer |
| * 0(%r15) - 63(%r15) scratch memory array with BPF_MEMWORDS |
| */ |
| int bpf_jit_enable __read_mostly; |
| |
| /* |
| * assembly code in arch/x86/net/bpf_jit.S |
| */ |
| extern u8 sk_load_word[], sk_load_half[], sk_load_byte[], sk_load_byte_msh[]; |
| extern u8 sk_load_word_ind[], sk_load_half_ind[], sk_load_byte_ind[]; |
| |
| struct bpf_jit { |
| unsigned int seen; |
| u8 *start; |
| u8 *prg; |
| u8 *mid; |
| u8 *lit; |
| u8 *end; |
| u8 *base_ip; |
| u8 *ret0_ip; |
| u8 *exit_ip; |
| unsigned int off_load_word; |
| unsigned int off_load_half; |
| unsigned int off_load_byte; |
| unsigned int off_load_bmsh; |
| unsigned int off_load_iword; |
| unsigned int off_load_ihalf; |
| unsigned int off_load_ibyte; |
| }; |
| |
| #define BPF_SIZE_MAX 4096 /* Max size for program */ |
| |
| #define SEEN_DATAREF 1 /* might call external helpers */ |
| #define SEEN_XREG 2 /* ebx is used */ |
| #define SEEN_MEM 4 /* use mem[] for temporary storage */ |
| #define SEEN_RET0 8 /* pc_ret0 points to a valid return 0 */ |
| #define SEEN_LITERAL 16 /* code uses literals */ |
| #define SEEN_LOAD_WORD 32 /* code uses sk_load_word */ |
| #define SEEN_LOAD_HALF 64 /* code uses sk_load_half */ |
| #define SEEN_LOAD_BYTE 128 /* code uses sk_load_byte */ |
| #define SEEN_LOAD_BMSH 256 /* code uses sk_load_byte_msh */ |
| #define SEEN_LOAD_IWORD 512 /* code uses sk_load_word_ind */ |
| #define SEEN_LOAD_IHALF 1024 /* code uses sk_load_half_ind */ |
| #define SEEN_LOAD_IBYTE 2048 /* code uses sk_load_byte_ind */ |
| |
| #define EMIT2(op) \ |
| ({ \ |
| if (jit->prg + 2 <= jit->mid) \ |
| *(u16 *) jit->prg = op; \ |
| jit->prg += 2; \ |
| }) |
| |
| #define EMIT4(op) \ |
| ({ \ |
| if (jit->prg + 4 <= jit->mid) \ |
| *(u32 *) jit->prg = op; \ |
| jit->prg += 4; \ |
| }) |
| |
| #define EMIT4_DISP(op, disp) \ |
| ({ \ |
| unsigned int __disp = (disp) & 0xfff; \ |
| EMIT4(op | __disp); \ |
| }) |
| |
| #define EMIT4_IMM(op, imm) \ |
| ({ \ |
| unsigned int __imm = (imm) & 0xffff; \ |
| EMIT4(op | __imm); \ |
| }) |
| |
| #define EMIT4_PCREL(op, pcrel) \ |
| ({ \ |
| long __pcrel = ((pcrel) >> 1) & 0xffff; \ |
| EMIT4(op | __pcrel); \ |
| }) |
| |
| #define EMIT6(op1, op2) \ |
| ({ \ |
| if (jit->prg + 6 <= jit->mid) { \ |
| *(u32 *) jit->prg = op1; \ |
| *(u16 *) (jit->prg + 4) = op2; \ |
| } \ |
| jit->prg += 6; \ |
| }) |
| |
| #define EMIT6_DISP(op1, op2, disp) \ |
| ({ \ |
| unsigned int __disp = (disp) & 0xfff; \ |
| EMIT6(op1 | __disp, op2); \ |
| }) |
| |
| #define EMIT6_IMM(op, imm) \ |
| ({ \ |
| unsigned int __imm = (imm); \ |
| EMIT6(op | (__imm >> 16), __imm & 0xffff); \ |
| }) |
| |
| #define EMIT_CONST(val) \ |
| ({ \ |
| unsigned int ret; \ |
| ret = (unsigned int) (jit->lit - jit->base_ip); \ |
| jit->seen |= SEEN_LITERAL; \ |
| if (jit->lit + 4 <= jit->end) \ |
| *(u32 *) jit->lit = val; \ |
| jit->lit += 4; \ |
| ret; \ |
| }) |
| |
| #define EMIT_FN_CONST(bit, fn) \ |
| ({ \ |
| unsigned int ret; \ |
| ret = (unsigned int) (jit->lit - jit->base_ip); \ |
| if (jit->seen & bit) { \ |
| jit->seen |= SEEN_LITERAL; \ |
| if (jit->lit + 8 <= jit->end) \ |
| *(void **) jit->lit = fn; \ |
| jit->lit += 8; \ |
| } \ |
| ret; \ |
| }) |
| |
| static void bpf_jit_prologue(struct bpf_jit *jit) |
| { |
| /* Save registers and create stack frame if necessary */ |
| if (jit->seen & SEEN_DATAREF) { |
| /* stmg %r8,%r15,88(%r15) */ |
| EMIT6(0xeb8ff058, 0x0024); |
| /* lgr %r14,%r15 */ |
| EMIT4(0xb90400ef); |
| /* ahi %r15,<offset> */ |
| EMIT4_IMM(0xa7fa0000, (jit->seen & SEEN_MEM) ? -112 : -80); |
| /* stg %r14,152(%r15) */ |
| EMIT6(0xe3e0f098, 0x0024); |
| } else if ((jit->seen & SEEN_XREG) && (jit->seen & SEEN_LITERAL)) |
| /* stmg %r12,%r13,120(%r15) */ |
| EMIT6(0xebcdf078, 0x0024); |
| else if (jit->seen & SEEN_XREG) |
| /* stg %r12,120(%r15) */ |
| EMIT6(0xe3c0f078, 0x0024); |
| else if (jit->seen & SEEN_LITERAL) |
| /* stg %r13,128(%r15) */ |
| EMIT6(0xe3d0f080, 0x0024); |
| |
| /* Setup literal pool */ |
| if (jit->seen & SEEN_LITERAL) { |
| /* basr %r13,0 */ |
| EMIT2(0x0dd0); |
| jit->base_ip = jit->prg; |
| } |
| jit->off_load_word = EMIT_FN_CONST(SEEN_LOAD_WORD, sk_load_word); |
| jit->off_load_half = EMIT_FN_CONST(SEEN_LOAD_HALF, sk_load_half); |
| jit->off_load_byte = EMIT_FN_CONST(SEEN_LOAD_BYTE, sk_load_byte); |
| jit->off_load_bmsh = EMIT_FN_CONST(SEEN_LOAD_BMSH, sk_load_byte_msh); |
| jit->off_load_iword = EMIT_FN_CONST(SEEN_LOAD_IWORD, sk_load_word_ind); |
| jit->off_load_ihalf = EMIT_FN_CONST(SEEN_LOAD_IHALF, sk_load_half_ind); |
| jit->off_load_ibyte = EMIT_FN_CONST(SEEN_LOAD_IBYTE, sk_load_byte_ind); |
| |
| /* Filter needs to access skb data */ |
| if (jit->seen & SEEN_DATAREF) { |
| /* l %r11,<len>(%r2) */ |
| EMIT4_DISP(0x58b02000, offsetof(struct sk_buff, len)); |
| /* s %r11,<data_len>(%r2) */ |
| EMIT4_DISP(0x5bb02000, offsetof(struct sk_buff, data_len)); |
| /* lg %r10,<data>(%r2) */ |
| EMIT6_DISP(0xe3a02000, 0x0004, |
| offsetof(struct sk_buff, data)); |
| } |
| } |
| |
| static void bpf_jit_epilogue(struct bpf_jit *jit) |
| { |
| /* Return 0 */ |
| if (jit->seen & SEEN_RET0) { |
| jit->ret0_ip = jit->prg; |
| /* lghi %r2,0 */ |
| EMIT4(0xa7290000); |
| } |
| jit->exit_ip = jit->prg; |
| /* Restore registers */ |
| if (jit->seen & SEEN_DATAREF) |
| /* lmg %r8,%r15,<offset>(%r15) */ |
| EMIT6_DISP(0xeb8ff000, 0x0004, |
| (jit->seen & SEEN_MEM) ? 200 : 168); |
| else if ((jit->seen & SEEN_XREG) && (jit->seen & SEEN_LITERAL)) |
| /* lmg %r12,%r13,120(%r15) */ |
| EMIT6(0xebcdf078, 0x0004); |
| else if (jit->seen & SEEN_XREG) |
| /* lg %r12,120(%r15) */ |
| EMIT6(0xe3c0f078, 0x0004); |
| else if (jit->seen & SEEN_LITERAL) |
| /* lg %r13,128(%r15) */ |
| EMIT6(0xe3d0f080, 0x0004); |
| /* br %r14 */ |
| EMIT2(0x07fe); |
| } |
| |
| /* |
| * make sure we dont leak kernel information to user |
| */ |
| static void bpf_jit_noleaks(struct bpf_jit *jit, struct sock_filter *filter) |
| { |
| /* Clear temporary memory if (seen & SEEN_MEM) */ |
| if (jit->seen & SEEN_MEM) |
| /* xc 0(64,%r15),0(%r15) */ |
| EMIT6(0xd73ff000, 0xf000); |
| /* Clear X if (seen & SEEN_XREG) */ |
| if (jit->seen & SEEN_XREG) |
| /* lhi %r12,0 */ |
| EMIT4(0xa7c80000); |
| /* Clear A if the first register does not set it. */ |
| switch (filter[0].code) { |
| case BPF_S_LD_W_ABS: |
| case BPF_S_LD_H_ABS: |
| case BPF_S_LD_B_ABS: |
| case BPF_S_LD_W_LEN: |
| case BPF_S_LD_W_IND: |
| case BPF_S_LD_H_IND: |
| case BPF_S_LD_B_IND: |
| case BPF_S_LD_IMM: |
| case BPF_S_LD_MEM: |
| case BPF_S_MISC_TXA: |
| case BPF_S_ANC_PROTOCOL: |
| case BPF_S_ANC_PKTTYPE: |
| case BPF_S_ANC_IFINDEX: |
| case BPF_S_ANC_MARK: |
| case BPF_S_ANC_QUEUE: |
| case BPF_S_ANC_HATYPE: |
| case BPF_S_ANC_RXHASH: |
| case BPF_S_ANC_CPU: |
| case BPF_S_ANC_VLAN_TAG: |
| case BPF_S_ANC_VLAN_TAG_PRESENT: |
| case BPF_S_RET_K: |
| /* first instruction sets A register */ |
| break; |
| default: /* A = 0 */ |
| /* lhi %r5,0 */ |
| EMIT4(0xa7580000); |
| } |
| } |
| |
| static int bpf_jit_insn(struct bpf_jit *jit, struct sock_filter *filter, |
| unsigned int *addrs, int i, int last) |
| { |
| unsigned int K; |
| int offset; |
| unsigned int mask; |
| |
| K = filter->k; |
| switch (filter->code) { |
| case BPF_S_ALU_ADD_X: /* A += X */ |
| jit->seen |= SEEN_XREG; |
| /* ar %r5,%r12 */ |
| EMIT2(0x1a5c); |
| break; |
| case BPF_S_ALU_ADD_K: /* A += K */ |
| if (!K) |
| break; |
| if (K <= 16383) |
| /* ahi %r5,<K> */ |
| EMIT4_IMM(0xa75a0000, K); |
| else if (test_facility(21)) |
| /* alfi %r5,<K> */ |
| EMIT6_IMM(0xc25b0000, K); |
| else |
| /* a %r5,<d(K)>(%r13) */ |
| EMIT4_DISP(0x5a50d000, EMIT_CONST(K)); |
| break; |
| case BPF_S_ALU_SUB_X: /* A -= X */ |
| jit->seen |= SEEN_XREG; |
| /* sr %r5,%r12 */ |
| EMIT2(0x1b5c); |
| break; |
| case BPF_S_ALU_SUB_K: /* A -= K */ |
| if (!K) |
| break; |
| if (K <= 16384) |
| /* ahi %r5,-K */ |
| EMIT4_IMM(0xa75a0000, -K); |
| else if (test_facility(21)) |
| /* alfi %r5,-K */ |
| EMIT6_IMM(0xc25b0000, -K); |
| else |
| /* s %r5,<d(K)>(%r13) */ |
| EMIT4_DISP(0x5b50d000, EMIT_CONST(K)); |
| break; |
| case BPF_S_ALU_MUL_X: /* A *= X */ |
| jit->seen |= SEEN_XREG; |
| /* msr %r5,%r12 */ |
| EMIT4(0xb252005c); |
| break; |
| case BPF_S_ALU_MUL_K: /* A *= K */ |
| if (K <= 16383) |
| /* mhi %r5,K */ |
| EMIT4_IMM(0xa75c0000, K); |
| else if (test_facility(34)) |
| /* msfi %r5,<K> */ |
| EMIT6_IMM(0xc2510000, K); |
| else |
| /* ms %r5,<d(K)>(%r13) */ |
| EMIT4_DISP(0x7150d000, EMIT_CONST(K)); |
| break; |
| case BPF_S_ALU_DIV_X: /* A /= X */ |
| jit->seen |= SEEN_XREG | SEEN_RET0; |
| /* ltr %r12,%r12 */ |
| EMIT2(0x12cc); |
| /* jz <ret0> */ |
| EMIT4_PCREL(0xa7840000, (jit->ret0_ip - jit->prg)); |
| /* lhi %r4,0 */ |
| EMIT4(0xa7480000); |
| /* dlr %r4,%r12 */ |
| EMIT4(0xb997004c); |
| break; |
| case BPF_S_ALU_DIV_K: /* A /= K */ |
| if (K == 1) |
| break; |
| /* lhi %r4,0 */ |
| EMIT4(0xa7480000); |
| /* dl %r4,<d(K)>(%r13) */ |
| EMIT6_DISP(0xe340d000, 0x0097, EMIT_CONST(K)); |
| break; |
| case BPF_S_ALU_MOD_X: /* A %= X */ |
| jit->seen |= SEEN_XREG | SEEN_RET0; |
| /* ltr %r12,%r12 */ |
| EMIT2(0x12cc); |
| /* jz <ret0> */ |
| EMIT4_PCREL(0xa7840000, (jit->ret0_ip - jit->prg)); |
| /* lhi %r4,0 */ |
| EMIT4(0xa7480000); |
| /* dlr %r4,%r12 */ |
| EMIT4(0xb997004c); |
| /* lr %r5,%r4 */ |
| EMIT2(0x1854); |
| break; |
| case BPF_S_ALU_MOD_K: /* A %= K */ |
| if (K == 1) { |
| /* lhi %r5,0 */ |
| EMIT4(0xa7580000); |
| break; |
| } |
| /* lhi %r4,0 */ |
| EMIT4(0xa7480000); |
| /* dl %r4,<d(K)>(%r13) */ |
| EMIT6_DISP(0xe340d000, 0x0097, EMIT_CONST(K)); |
| /* lr %r5,%r4 */ |
| EMIT2(0x1854); |
| break; |
| case BPF_S_ALU_AND_X: /* A &= X */ |
| jit->seen |= SEEN_XREG; |
| /* nr %r5,%r12 */ |
| EMIT2(0x145c); |
| break; |
| case BPF_S_ALU_AND_K: /* A &= K */ |
| if (test_facility(21)) |
| /* nilf %r5,<K> */ |
| EMIT6_IMM(0xc05b0000, K); |
| else |
| /* n %r5,<d(K)>(%r13) */ |
| EMIT4_DISP(0x5450d000, EMIT_CONST(K)); |
| break; |
| case BPF_S_ALU_OR_X: /* A |= X */ |
| jit->seen |= SEEN_XREG; |
| /* or %r5,%r12 */ |
| EMIT2(0x165c); |
| break; |
| case BPF_S_ALU_OR_K: /* A |= K */ |
| if (test_facility(21)) |
| /* oilf %r5,<K> */ |
| EMIT6_IMM(0xc05d0000, K); |
| else |
| /* o %r5,<d(K)>(%r13) */ |
| EMIT4_DISP(0x5650d000, EMIT_CONST(K)); |
| break; |
| case BPF_S_ANC_ALU_XOR_X: /* A ^= X; */ |
| case BPF_S_ALU_XOR_X: |
| jit->seen |= SEEN_XREG; |
| /* xr %r5,%r12 */ |
| EMIT2(0x175c); |
| break; |
| case BPF_S_ALU_XOR_K: /* A ^= K */ |
| if (!K) |
| break; |
| /* x %r5,<d(K)>(%r13) */ |
| EMIT4_DISP(0x5750d000, EMIT_CONST(K)); |
| break; |
| case BPF_S_ALU_LSH_X: /* A <<= X; */ |
| jit->seen |= SEEN_XREG; |
| /* sll %r5,0(%r12) */ |
| EMIT4(0x8950c000); |
| break; |
| case BPF_S_ALU_LSH_K: /* A <<= K */ |
| if (K == 0) |
| break; |
| /* sll %r5,K */ |
| EMIT4_DISP(0x89500000, K); |
| break; |
| case BPF_S_ALU_RSH_X: /* A >>= X; */ |
| jit->seen |= SEEN_XREG; |
| /* srl %r5,0(%r12) */ |
| EMIT4(0x8850c000); |
| break; |
| case BPF_S_ALU_RSH_K: /* A >>= K; */ |
| if (K == 0) |
| break; |
| /* srl %r5,K */ |
| EMIT4_DISP(0x88500000, K); |
| break; |
| case BPF_S_ALU_NEG: /* A = -A */ |
| /* lnr %r5,%r5 */ |
| EMIT2(0x1155); |
| break; |
| case BPF_S_JMP_JA: /* ip += K */ |
| offset = addrs[i + K] + jit->start - jit->prg; |
| EMIT4_PCREL(0xa7f40000, offset); |
| break; |
| case BPF_S_JMP_JGT_K: /* ip += (A > K) ? jt : jf */ |
| mask = 0x200000; /* jh */ |
| goto kbranch; |
| case BPF_S_JMP_JGE_K: /* ip += (A >= K) ? jt : jf */ |
| mask = 0xa00000; /* jhe */ |
| goto kbranch; |
| case BPF_S_JMP_JEQ_K: /* ip += (A == K) ? jt : jf */ |
| mask = 0x800000; /* je */ |
| kbranch: /* Emit compare if the branch targets are different */ |
| if (filter->jt != filter->jf) { |
| if (K <= 16383) |
| /* chi %r5,<K> */ |
| EMIT4_IMM(0xa75e0000, K); |
| else if (test_facility(21)) |
| /* clfi %r5,<K> */ |
| EMIT6_IMM(0xc25f0000, K); |
| else |
| /* c %r5,<d(K)>(%r13) */ |
| EMIT4_DISP(0x5950d000, EMIT_CONST(K)); |
| } |
| branch: if (filter->jt == filter->jf) { |
| if (filter->jt == 0) |
| break; |
| /* j <jt> */ |
| offset = addrs[i + filter->jt] + jit->start - jit->prg; |
| EMIT4_PCREL(0xa7f40000, offset); |
| break; |
| } |
| if (filter->jt != 0) { |
| /* brc <mask>,<jt> */ |
| offset = addrs[i + filter->jt] + jit->start - jit->prg; |
| EMIT4_PCREL(0xa7040000 | mask, offset); |
| } |
| if (filter->jf != 0) { |
| /* brc <mask^15>,<jf> */ |
| offset = addrs[i + filter->jf] + jit->start - jit->prg; |
| EMIT4_PCREL(0xa7040000 | (mask ^ 0xf00000), offset); |
| } |
| break; |
| case BPF_S_JMP_JSET_K: /* ip += (A & K) ? jt : jf */ |
| mask = 0x700000; /* jnz */ |
| /* Emit test if the branch targets are different */ |
| if (filter->jt != filter->jf) { |
| if (K > 65535) { |
| /* lr %r4,%r5 */ |
| EMIT2(0x1845); |
| /* n %r4,<d(K)>(%r13) */ |
| EMIT4_DISP(0x5440d000, EMIT_CONST(K)); |
| } else |
| /* tmll %r5,K */ |
| EMIT4_IMM(0xa7510000, K); |
| } |
| goto branch; |
| case BPF_S_JMP_JGT_X: /* ip += (A > X) ? jt : jf */ |
| mask = 0x200000; /* jh */ |
| goto xbranch; |
| case BPF_S_JMP_JGE_X: /* ip += (A >= X) ? jt : jf */ |
| mask = 0xa00000; /* jhe */ |
| goto xbranch; |
| case BPF_S_JMP_JEQ_X: /* ip += (A == X) ? jt : jf */ |
| mask = 0x800000; /* je */ |
| xbranch: /* Emit compare if the branch targets are different */ |
| if (filter->jt != filter->jf) { |
| jit->seen |= SEEN_XREG; |
| /* cr %r5,%r12 */ |
| EMIT2(0x195c); |
| } |
| goto branch; |
| case BPF_S_JMP_JSET_X: /* ip += (A & X) ? jt : jf */ |
| mask = 0x700000; /* jnz */ |
| /* Emit test if the branch targets are different */ |
| if (filter->jt != filter->jf) { |
| jit->seen |= SEEN_XREG; |
| /* lr %r4,%r5 */ |
| EMIT2(0x1845); |
| /* nr %r4,%r12 */ |
| EMIT2(0x144c); |
| } |
| goto branch; |
| case BPF_S_LD_W_ABS: /* A = *(u32 *) (skb->data+K) */ |
| jit->seen |= SEEN_DATAREF | SEEN_RET0 | SEEN_LOAD_WORD; |
| offset = jit->off_load_word; |
| goto load_abs; |
| case BPF_S_LD_H_ABS: /* A = *(u16 *) (skb->data+K) */ |
| jit->seen |= SEEN_DATAREF | SEEN_RET0 | SEEN_LOAD_HALF; |
| offset = jit->off_load_half; |
| goto load_abs; |
| case BPF_S_LD_B_ABS: /* A = *(u8 *) (skb->data+K) */ |
| jit->seen |= SEEN_DATAREF | SEEN_RET0 | SEEN_LOAD_BYTE; |
| offset = jit->off_load_byte; |
| load_abs: if ((int) K < 0) |
| goto out; |
| call_fn: /* lg %r1,<d(function)>(%r13) */ |
| EMIT6_DISP(0xe310d000, 0x0004, offset); |
| /* l %r3,<d(K)>(%r13) */ |
| EMIT4_DISP(0x5830d000, EMIT_CONST(K)); |
| /* basr %r8,%r1 */ |
| EMIT2(0x0d81); |
| /* jnz <ret0> */ |
| EMIT4_PCREL(0xa7740000, (jit->ret0_ip - jit->prg)); |
| break; |
| case BPF_S_LD_W_IND: /* A = *(u32 *) (skb->data+K+X) */ |
| jit->seen |= SEEN_DATAREF | SEEN_RET0 | SEEN_LOAD_IWORD; |
| offset = jit->off_load_iword; |
| goto call_fn; |
| case BPF_S_LD_H_IND: /* A = *(u16 *) (skb->data+K+X) */ |
| jit->seen |= SEEN_DATAREF | SEEN_RET0 | SEEN_LOAD_IHALF; |
| offset = jit->off_load_ihalf; |
| goto call_fn; |
| case BPF_S_LD_B_IND: /* A = *(u8 *) (skb->data+K+X) */ |
| jit->seen |= SEEN_DATAREF | SEEN_RET0 | SEEN_LOAD_IBYTE; |
| offset = jit->off_load_ibyte; |
| goto call_fn; |
| case BPF_S_LDX_B_MSH: |
| /* X = (*(u8 *)(skb->data+K) & 0xf) << 2 */ |
| jit->seen |= SEEN_RET0; |
| if ((int) K < 0) { |
| /* j <ret0> */ |
| EMIT4_PCREL(0xa7f40000, (jit->ret0_ip - jit->prg)); |
| break; |
| } |
| jit->seen |= SEEN_DATAREF | SEEN_LOAD_BMSH; |
| offset = jit->off_load_bmsh; |
| goto call_fn; |
| case BPF_S_LD_W_LEN: /* A = skb->len; */ |
| BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, len) != 4); |
| /* l %r5,<d(len)>(%r2) */ |
| EMIT4_DISP(0x58502000, offsetof(struct sk_buff, len)); |
| break; |
| case BPF_S_LDX_W_LEN: /* X = skb->len; */ |
| jit->seen |= SEEN_XREG; |
| /* l %r12,<d(len)>(%r2) */ |
| EMIT4_DISP(0x58c02000, offsetof(struct sk_buff, len)); |
| break; |
| case BPF_S_LD_IMM: /* A = K */ |
| if (K <= 16383) |
| /* lhi %r5,K */ |
| EMIT4_IMM(0xa7580000, K); |
| else if (test_facility(21)) |
| /* llilf %r5,<K> */ |
| EMIT6_IMM(0xc05f0000, K); |
| else |
| /* l %r5,<d(K)>(%r13) */ |
| EMIT4_DISP(0x5850d000, EMIT_CONST(K)); |
| break; |
| case BPF_S_LDX_IMM: /* X = K */ |
| jit->seen |= SEEN_XREG; |
| if (K <= 16383) |
| /* lhi %r12,<K> */ |
| EMIT4_IMM(0xa7c80000, K); |
| else if (test_facility(21)) |
| /* llilf %r12,<K> */ |
| EMIT6_IMM(0xc0cf0000, K); |
| else |
| /* l %r12,<d(K)>(%r13) */ |
| EMIT4_DISP(0x58c0d000, EMIT_CONST(K)); |
| break; |
| case BPF_S_LD_MEM: /* A = mem[K] */ |
| jit->seen |= SEEN_MEM; |
| /* l %r5,<K>(%r15) */ |
| EMIT4_DISP(0x5850f000, |
| (jit->seen & SEEN_DATAREF) ? 160 + K*4 : K*4); |
| break; |
| case BPF_S_LDX_MEM: /* X = mem[K] */ |
| jit->seen |= SEEN_XREG | SEEN_MEM; |
| /* l %r12,<K>(%r15) */ |
| EMIT4_DISP(0x58c0f000, |
| (jit->seen & SEEN_DATAREF) ? 160 + K*4 : K*4); |
| break; |
| case BPF_S_MISC_TAX: /* X = A */ |
| jit->seen |= SEEN_XREG; |
| /* lr %r12,%r5 */ |
| EMIT2(0x18c5); |
| break; |
| case BPF_S_MISC_TXA: /* A = X */ |
| jit->seen |= SEEN_XREG; |
| /* lr %r5,%r12 */ |
| EMIT2(0x185c); |
| break; |
| case BPF_S_RET_K: |
| if (K == 0) { |
| jit->seen |= SEEN_RET0; |
| if (last) |
| break; |
| /* j <ret0> */ |
| EMIT4_PCREL(0xa7f40000, jit->ret0_ip - jit->prg); |
| } else { |
| if (K <= 16383) |
| /* lghi %r2,K */ |
| EMIT4_IMM(0xa7290000, K); |
| else |
| /* llgf %r2,<K>(%r13) */ |
| EMIT6_DISP(0xe320d000, 0x0016, EMIT_CONST(K)); |
| /* j <exit> */ |
| if (last && !(jit->seen & SEEN_RET0)) |
| break; |
| EMIT4_PCREL(0xa7f40000, jit->exit_ip - jit->prg); |
| } |
| break; |
| case BPF_S_RET_A: |
| /* llgfr %r2,%r5 */ |
| EMIT4(0xb9160025); |
| /* j <exit> */ |
| EMIT4_PCREL(0xa7f40000, jit->exit_ip - jit->prg); |
| break; |
| case BPF_S_ST: /* mem[K] = A */ |
| jit->seen |= SEEN_MEM; |
| /* st %r5,<K>(%r15) */ |
| EMIT4_DISP(0x5050f000, |
| (jit->seen & SEEN_DATAREF) ? 160 + K*4 : K*4); |
| break; |
| case BPF_S_STX: /* mem[K] = X : mov %ebx,off8(%rbp) */ |
| jit->seen |= SEEN_XREG | SEEN_MEM; |
| /* st %r12,<K>(%r15) */ |
| EMIT4_DISP(0x50c0f000, |
| (jit->seen & SEEN_DATAREF) ? 160 + K*4 : K*4); |
| break; |
| case BPF_S_ANC_PROTOCOL: /* A = ntohs(skb->protocol); */ |
| BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, protocol) != 2); |
| /* lhi %r5,0 */ |
| EMIT4(0xa7580000); |
| /* icm %r5,3,<d(protocol)>(%r2) */ |
| EMIT4_DISP(0xbf532000, offsetof(struct sk_buff, protocol)); |
| break; |
| case BPF_S_ANC_IFINDEX: /* if (!skb->dev) return 0; |
| * A = skb->dev->ifindex */ |
| BUILD_BUG_ON(FIELD_SIZEOF(struct net_device, ifindex) != 4); |
| jit->seen |= SEEN_RET0; |
| /* lg %r1,<d(dev)>(%r2) */ |
| EMIT6_DISP(0xe3102000, 0x0004, offsetof(struct sk_buff, dev)); |
| /* ltgr %r1,%r1 */ |
| EMIT4(0xb9020011); |
| /* jz <ret0> */ |
| EMIT4_PCREL(0xa7840000, jit->ret0_ip - jit->prg); |
| /* l %r5,<d(ifindex)>(%r1) */ |
| EMIT4_DISP(0x58501000, offsetof(struct net_device, ifindex)); |
| break; |
| case BPF_S_ANC_MARK: /* A = skb->mark */ |
| BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, mark) != 4); |
| /* l %r5,<d(mark)>(%r2) */ |
| EMIT4_DISP(0x58502000, offsetof(struct sk_buff, mark)); |
| break; |
| case BPF_S_ANC_QUEUE: /* A = skb->queue_mapping */ |
| BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, queue_mapping) != 2); |
| /* lhi %r5,0 */ |
| EMIT4(0xa7580000); |
| /* icm %r5,3,<d(queue_mapping)>(%r2) */ |
| EMIT4_DISP(0xbf532000, offsetof(struct sk_buff, queue_mapping)); |
| break; |
| case BPF_S_ANC_HATYPE: /* if (!skb->dev) return 0; |
| * A = skb->dev->type */ |
| BUILD_BUG_ON(FIELD_SIZEOF(struct net_device, type) != 2); |
| jit->seen |= SEEN_RET0; |
| /* lg %r1,<d(dev)>(%r2) */ |
| EMIT6_DISP(0xe3102000, 0x0004, offsetof(struct sk_buff, dev)); |
| /* ltgr %r1,%r1 */ |
| EMIT4(0xb9020011); |
| /* jz <ret0> */ |
| EMIT4_PCREL(0xa7840000, jit->ret0_ip - jit->prg); |
| /* lhi %r5,0 */ |
| EMIT4(0xa7580000); |
| /* icm %r5,3,<d(type)>(%r1) */ |
| EMIT4_DISP(0xbf531000, offsetof(struct net_device, type)); |
| break; |
| case BPF_S_ANC_RXHASH: /* A = skb->rxhash */ |
| BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, rxhash) != 4); |
| /* l %r5,<d(rxhash)>(%r2) */ |
| EMIT4_DISP(0x58502000, offsetof(struct sk_buff, rxhash)); |
| break; |
| case BPF_S_ANC_VLAN_TAG: |
| case BPF_S_ANC_VLAN_TAG_PRESENT: |
| BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, vlan_tci) != 2); |
| BUILD_BUG_ON(VLAN_TAG_PRESENT != 0x1000); |
| /* lhi %r5,0 */ |
| EMIT4(0xa7580000); |
| /* icm %r5,3,<d(vlan_tci)>(%r2) */ |
| EMIT4_DISP(0xbf532000, offsetof(struct sk_buff, vlan_tci)); |
| if (filter->code == BPF_S_ANC_VLAN_TAG) { |
| /* nill %r5,0xefff */ |
| EMIT4_IMM(0xa5570000, ~VLAN_TAG_PRESENT); |
| } else { |
| /* nill %r5,0x1000 */ |
| EMIT4_IMM(0xa5570000, VLAN_TAG_PRESENT); |
| /* srl %r5,12 */ |
| EMIT4_DISP(0x88500000, 12); |
| } |
| break; |
| case BPF_S_ANC_CPU: /* A = smp_processor_id() */ |
| #ifdef CONFIG_SMP |
| /* l %r5,<d(cpu_nr)> */ |
| EMIT4_DISP(0x58500000, offsetof(struct _lowcore, cpu_nr)); |
| #else |
| /* lhi %r5,0 */ |
| EMIT4(0xa7580000); |
| #endif |
| break; |
| default: /* too complex, give up */ |
| goto out; |
| } |
| addrs[i] = jit->prg - jit->start; |
| return 0; |
| out: |
| return -1; |
| } |
| |
| void bpf_jit_compile(struct sk_filter *fp) |
| { |
| unsigned long size, prg_len, lit_len; |
| struct bpf_jit jit, cjit; |
| unsigned int *addrs; |
| int pass, i; |
| |
| if (!bpf_jit_enable) |
| return; |
| addrs = kcalloc(fp->len, sizeof(*addrs), GFP_KERNEL); |
| if (addrs == NULL) |
| return; |
| memset(&jit, 0, sizeof(cjit)); |
| memset(&cjit, 0, sizeof(cjit)); |
| |
| for (pass = 0; pass < 10; pass++) { |
| jit.prg = jit.start; |
| jit.lit = jit.mid; |
| |
| bpf_jit_prologue(&jit); |
| bpf_jit_noleaks(&jit, fp->insns); |
| for (i = 0; i < fp->len; i++) { |
| if (bpf_jit_insn(&jit, fp->insns + i, addrs, i, |
| i == fp->len - 1)) |
| goto out; |
| } |
| bpf_jit_epilogue(&jit); |
| if (jit.start) { |
| WARN_ON(jit.prg > cjit.prg || jit.lit > cjit.lit); |
| if (memcmp(&jit, &cjit, sizeof(jit)) == 0) |
| break; |
| } else if (jit.prg == cjit.prg && jit.lit == cjit.lit) { |
| prg_len = jit.prg - jit.start; |
| lit_len = jit.lit - jit.mid; |
| size = max_t(unsigned long, prg_len + lit_len, |
| sizeof(struct work_struct)); |
| if (size >= BPF_SIZE_MAX) |
| goto out; |
| jit.start = module_alloc(size); |
| if (!jit.start) |
| goto out; |
| jit.prg = jit.mid = jit.start + prg_len; |
| jit.lit = jit.end = jit.start + prg_len + lit_len; |
| jit.base_ip += (unsigned long) jit.start; |
| jit.exit_ip += (unsigned long) jit.start; |
| jit.ret0_ip += (unsigned long) jit.start; |
| } |
| cjit = jit; |
| } |
| if (bpf_jit_enable > 1) { |
| pr_err("flen=%d proglen=%lu pass=%d image=%p\n", |
| fp->len, jit.end - jit.start, pass, jit.start); |
| if (jit.start) { |
| printk(KERN_ERR "JIT code:\n"); |
| print_fn_code(jit.start, jit.mid - jit.start); |
| print_hex_dump(KERN_ERR, "JIT literals:\n", |
| DUMP_PREFIX_ADDRESS, 16, 1, |
| jit.mid, jit.end - jit.mid, false); |
| } |
| } |
| if (jit.start) |
| fp->bpf_func = (void *) jit.start; |
| out: |
| kfree(addrs); |
| } |
| |
| static void jit_free_defer(struct work_struct *arg) |
| { |
| module_free(NULL, arg); |
| } |
| |
| /* run from softirq, we must use a work_struct to call |
| * module_free() from process context |
| */ |
| void bpf_jit_free(struct sk_filter *fp) |
| { |
| struct work_struct *work; |
| |
| if (fp->bpf_func == sk_run_filter) |
| return; |
| work = (struct work_struct *)fp->bpf_func; |
| INIT_WORK(work, jit_free_defer); |
| schedule_work(work); |
| } |