diff options
Diffstat (limited to 'arch/powerpc/net')
| -rw-r--r-- | arch/powerpc/net/Makefile | 9 | ||||
| -rw-r--r-- | arch/powerpc/net/bpf_jit.h | 272 | ||||
| -rw-r--r-- | arch/powerpc/net/bpf_jit32.h | 144 | ||||
| -rw-r--r-- | arch/powerpc/net/bpf_jit64.h | 112 | ||||
| -rw-r--r-- | arch/powerpc/net/bpf_jit_asm.S | 230 | ||||
| -rw-r--r-- | arch/powerpc/net/bpf_jit_comp.c | 689 | ||||
| -rw-r--r-- | arch/powerpc/net/bpf_jit_comp64.c | 1118 |
7 files changed, 2574 insertions, 0 deletions
diff --git a/arch/powerpc/net/Makefile b/arch/powerpc/net/Makefile new file mode 100644 index 000000000..c2dec3a68 --- /dev/null +++ b/arch/powerpc/net/Makefile @@ -0,0 +1,9 @@ +# SPDX-License-Identifier: GPL-2.0 +# +# Arch-specific network modules +# +ifdef CONFIG_PPC64 +obj-$(CONFIG_BPF_JIT) += bpf_jit_comp64.o +else +obj-$(CONFIG_BPF_JIT) += bpf_jit_asm.o bpf_jit_comp.o +endif diff --git a/arch/powerpc/net/bpf_jit.h b/arch/powerpc/net/bpf_jit.h new file mode 100644 index 000000000..5a0af7d8d --- /dev/null +++ b/arch/powerpc/net/bpf_jit.h @@ -0,0 +1,272 @@ +/* + * bpf_jit.h: BPF JIT compiler for PPC + * + * Copyright 2011 Matt Evans <matt@ozlabs.org>, IBM Corporation + * 2016 Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; version 2 + * of the License. + */ +#ifndef _BPF_JIT_H +#define _BPF_JIT_H + +#ifndef __ASSEMBLY__ + +#include <asm/types.h> +#include <asm/code-patching.h> + +#ifdef PPC64_ELF_ABI_v1 +#define FUNCTION_DESCR_SIZE 24 +#else +#define FUNCTION_DESCR_SIZE 0 +#endif + +/* + * 16-bit immediate helper macros: HA() is for use with sign-extending instrs + * (e.g. LD, ADDI). If the bottom 16 bits is "-ve", add another bit into the + * top half to negate the effect (i.e. 0xffff + 1 = 0x(1)0000). + */ +#define IMM_H(i) ((uintptr_t)(i)>>16) +#define IMM_HA(i) (((uintptr_t)(i)>>16) + \ + (((uintptr_t)(i) & 0x8000) >> 15)) +#define IMM_L(i) ((uintptr_t)(i) & 0xffff) + +#define PLANT_INSTR(d, idx, instr) \ + do { if (d) { (d)[idx] = instr; } idx++; } while (0) +#define EMIT(instr) PLANT_INSTR(image, ctx->idx, instr) + +#define PPC_NOP() EMIT(PPC_INST_NOP) +#define PPC_BLR() EMIT(PPC_INST_BLR) +#define PPC_BLRL() EMIT(PPC_INST_BLRL) +#define PPC_MTLR(r) EMIT(PPC_INST_MTLR | ___PPC_RT(r)) +#define PPC_BCTR() EMIT(PPC_INST_BCTR) +#define PPC_MTCTR(r) EMIT(PPC_INST_MTCTR | ___PPC_RT(r)) +#define PPC_ADDI(d, a, i) EMIT(PPC_INST_ADDI | ___PPC_RT(d) | \ + ___PPC_RA(a) | IMM_L(i)) +#define PPC_MR(d, a) PPC_OR(d, a, a) +#define PPC_LI(r, i) PPC_ADDI(r, 0, i) +#define PPC_ADDIS(d, a, i) EMIT(PPC_INST_ADDIS | \ + ___PPC_RT(d) | ___PPC_RA(a) | IMM_L(i)) +#define PPC_LIS(r, i) PPC_ADDIS(r, 0, i) +#define PPC_STD(r, base, i) EMIT(PPC_INST_STD | ___PPC_RS(r) | \ + ___PPC_RA(base) | ((i) & 0xfffc)) +#define PPC_STDX(r, base, b) EMIT(PPC_INST_STDX | ___PPC_RS(r) | \ + ___PPC_RA(base) | ___PPC_RB(b)) +#define PPC_STDU(r, base, i) EMIT(PPC_INST_STDU | ___PPC_RS(r) | \ + ___PPC_RA(base) | ((i) & 0xfffc)) +#define PPC_STW(r, base, i) EMIT(PPC_INST_STW | ___PPC_RS(r) | \ + ___PPC_RA(base) | IMM_L(i)) +#define PPC_STWU(r, base, i) EMIT(PPC_INST_STWU | ___PPC_RS(r) | \ + ___PPC_RA(base) | IMM_L(i)) +#define PPC_STH(r, base, i) EMIT(PPC_INST_STH | ___PPC_RS(r) | \ + ___PPC_RA(base) | IMM_L(i)) +#define PPC_STB(r, base, i) EMIT(PPC_INST_STB | ___PPC_RS(r) | \ + ___PPC_RA(base) | IMM_L(i)) + +#define PPC_LBZ(r, base, i) EMIT(PPC_INST_LBZ | ___PPC_RT(r) | \ + ___PPC_RA(base) | IMM_L(i)) +#define PPC_LD(r, base, i) EMIT(PPC_INST_LD | ___PPC_RT(r) | \ + ___PPC_RA(base) | ((i) & 0xfffc)) +#define PPC_LDX(r, base, b) EMIT(PPC_INST_LDX | ___PPC_RT(r) | \ + ___PPC_RA(base) | ___PPC_RB(b)) +#define PPC_LWZ(r, base, i) EMIT(PPC_INST_LWZ | ___PPC_RT(r) | \ + ___PPC_RA(base) | IMM_L(i)) +#define PPC_LHZ(r, base, i) EMIT(PPC_INST_LHZ | ___PPC_RT(r) | \ + ___PPC_RA(base) | IMM_L(i)) +#define PPC_LHBRX(r, base, b) EMIT(PPC_INST_LHBRX | ___PPC_RT(r) | \ + ___PPC_RA(base) | ___PPC_RB(b)) +#define PPC_LDBRX(r, base, b) EMIT(PPC_INST_LDBRX | ___PPC_RT(r) | \ + ___PPC_RA(base) | ___PPC_RB(b)) + +#define PPC_BPF_LDARX(t, a, b, eh) EMIT(PPC_INST_LDARX | ___PPC_RT(t) | \ + ___PPC_RA(a) | ___PPC_RB(b) | \ + __PPC_EH(eh)) +#define PPC_BPF_LWARX(t, a, b, eh) EMIT(PPC_INST_LWARX | ___PPC_RT(t) | \ + ___PPC_RA(a) | ___PPC_RB(b) | \ + __PPC_EH(eh)) +#define PPC_BPF_STWCX(s, a, b) EMIT(PPC_INST_STWCX | ___PPC_RS(s) | \ + ___PPC_RA(a) | ___PPC_RB(b)) +#define PPC_BPF_STDCX(s, a, b) EMIT(PPC_INST_STDCX | ___PPC_RS(s) | \ + ___PPC_RA(a) | ___PPC_RB(b)) +#define PPC_CMPWI(a, i) EMIT(PPC_INST_CMPWI | ___PPC_RA(a) | IMM_L(i)) +#define PPC_CMPDI(a, i) EMIT(PPC_INST_CMPDI | ___PPC_RA(a) | IMM_L(i)) +#define PPC_CMPW(a, b) EMIT(PPC_INST_CMPW | ___PPC_RA(a) | \ + ___PPC_RB(b)) +#define PPC_CMPD(a, b) EMIT(PPC_INST_CMPD | ___PPC_RA(a) | \ + ___PPC_RB(b)) +#define PPC_CMPLWI(a, i) EMIT(PPC_INST_CMPLWI | ___PPC_RA(a) | IMM_L(i)) +#define PPC_CMPLDI(a, i) EMIT(PPC_INST_CMPLDI | ___PPC_RA(a) | IMM_L(i)) +#define PPC_CMPLW(a, b) EMIT(PPC_INST_CMPLW | ___PPC_RA(a) | \ + ___PPC_RB(b)) +#define PPC_CMPLD(a, b) EMIT(PPC_INST_CMPLD | ___PPC_RA(a) | \ + ___PPC_RB(b)) + +#define PPC_SUB(d, a, b) EMIT(PPC_INST_SUB | ___PPC_RT(d) | \ + ___PPC_RB(a) | ___PPC_RA(b)) +#define PPC_ADD(d, a, b) EMIT(PPC_INST_ADD | ___PPC_RT(d) | \ + ___PPC_RA(a) | ___PPC_RB(b)) +#define PPC_MULD(d, a, b) EMIT(PPC_INST_MULLD | ___PPC_RT(d) | \ + ___PPC_RA(a) | ___PPC_RB(b)) +#define PPC_MULW(d, a, b) EMIT(PPC_INST_MULLW | ___PPC_RT(d) | \ + ___PPC_RA(a) | ___PPC_RB(b)) +#define PPC_MULHWU(d, a, b) EMIT(PPC_INST_MULHWU | ___PPC_RT(d) | \ + ___PPC_RA(a) | ___PPC_RB(b)) +#define PPC_MULI(d, a, i) EMIT(PPC_INST_MULLI | ___PPC_RT(d) | \ + ___PPC_RA(a) | IMM_L(i)) +#define PPC_DIVWU(d, a, b) EMIT(PPC_INST_DIVWU | ___PPC_RT(d) | \ + ___PPC_RA(a) | ___PPC_RB(b)) +#define PPC_DIVDU(d, a, b) EMIT(PPC_INST_DIVDU | ___PPC_RT(d) | \ + ___PPC_RA(a) | ___PPC_RB(b)) +#define PPC_AND(d, a, b) EMIT(PPC_INST_AND | ___PPC_RA(d) | \ + ___PPC_RS(a) | ___PPC_RB(b)) +#define PPC_ANDI(d, a, i) EMIT(PPC_INST_ANDI | ___PPC_RA(d) | \ + ___PPC_RS(a) | IMM_L(i)) +#define PPC_AND_DOT(d, a, b) EMIT(PPC_INST_ANDDOT | ___PPC_RA(d) | \ + ___PPC_RS(a) | ___PPC_RB(b)) +#define PPC_OR(d, a, b) EMIT(PPC_INST_OR | ___PPC_RA(d) | \ + ___PPC_RS(a) | ___PPC_RB(b)) +#define PPC_MR(d, a) PPC_OR(d, a, a) +#define PPC_ORI(d, a, i) EMIT(PPC_INST_ORI | ___PPC_RA(d) | \ + ___PPC_RS(a) | IMM_L(i)) +#define PPC_ORIS(d, a, i) EMIT(PPC_INST_ORIS | ___PPC_RA(d) | \ + ___PPC_RS(a) | IMM_L(i)) +#define PPC_XOR(d, a, b) EMIT(PPC_INST_XOR | ___PPC_RA(d) | \ + ___PPC_RS(a) | ___PPC_RB(b)) +#define PPC_XORI(d, a, i) EMIT(PPC_INST_XORI | ___PPC_RA(d) | \ + ___PPC_RS(a) | IMM_L(i)) +#define PPC_XORIS(d, a, i) EMIT(PPC_INST_XORIS | ___PPC_RA(d) | \ + ___PPC_RS(a) | IMM_L(i)) +#define PPC_EXTSW(d, a) EMIT(PPC_INST_EXTSW | ___PPC_RA(d) | \ + ___PPC_RS(a)) +#define PPC_SLW(d, a, s) EMIT(PPC_INST_SLW | ___PPC_RA(d) | \ + ___PPC_RS(a) | ___PPC_RB(s)) +#define PPC_SLD(d, a, s) EMIT(PPC_INST_SLD | ___PPC_RA(d) | \ + ___PPC_RS(a) | ___PPC_RB(s)) +#define PPC_SRW(d, a, s) EMIT(PPC_INST_SRW | ___PPC_RA(d) | \ + ___PPC_RS(a) | ___PPC_RB(s)) +#define PPC_SRD(d, a, s) EMIT(PPC_INST_SRD | ___PPC_RA(d) | \ + ___PPC_RS(a) | ___PPC_RB(s)) +#define PPC_SRAD(d, a, s) EMIT(PPC_INST_SRAD | ___PPC_RA(d) | \ + ___PPC_RS(a) | ___PPC_RB(s)) +#define PPC_SRADI(d, a, i) EMIT(PPC_INST_SRADI | ___PPC_RA(d) | \ + ___PPC_RS(a) | __PPC_SH64(i)) +#define PPC_RLWINM(d, a, i, mb, me) EMIT(PPC_INST_RLWINM | ___PPC_RA(d) | \ + ___PPC_RS(a) | __PPC_SH(i) | \ + __PPC_MB(mb) | __PPC_ME(me)) +#define PPC_RLWIMI(d, a, i, mb, me) EMIT(PPC_INST_RLWIMI | ___PPC_RA(d) | \ + ___PPC_RS(a) | __PPC_SH(i) | \ + __PPC_MB(mb) | __PPC_ME(me)) +#define PPC_RLDICL(d, a, i, mb) EMIT(PPC_INST_RLDICL | ___PPC_RA(d) | \ + ___PPC_RS(a) | __PPC_SH64(i) | \ + __PPC_MB64(mb)) +#define PPC_RLDICR(d, a, i, me) EMIT(PPC_INST_RLDICR | ___PPC_RA(d) | \ + ___PPC_RS(a) | __PPC_SH64(i) | \ + __PPC_ME64(me)) + +/* slwi = rlwinm Rx, Ry, n, 0, 31-n */ +#define PPC_SLWI(d, a, i) PPC_RLWINM(d, a, i, 0, 31-(i)) +/* srwi = rlwinm Rx, Ry, 32-n, n, 31 */ +#define PPC_SRWI(d, a, i) PPC_RLWINM(d, a, 32-(i), i, 31) +/* sldi = rldicr Rx, Ry, n, 63-n */ +#define PPC_SLDI(d, a, i) PPC_RLDICR(d, a, i, 63-(i)) +/* sldi = rldicl Rx, Ry, 64-n, n */ +#define PPC_SRDI(d, a, i) PPC_RLDICL(d, a, 64-(i), i) + +#define PPC_NEG(d, a) EMIT(PPC_INST_NEG | ___PPC_RT(d) | ___PPC_RA(a)) + +/* Long jump; (unconditional 'branch') */ +#define PPC_JMP(dest) \ + do { \ + long offset = (long)(dest) - (ctx->idx * 4); \ + if (!is_offset_in_branch_range(offset)) { \ + pr_err_ratelimited("Branch offset 0x%lx (@%u) out of range\n", offset, ctx->idx); \ + return -ERANGE; \ + } \ + EMIT(PPC_INST_BRANCH | (offset & 0x03fffffc)); \ + } while (0) +/* "cond" here covers BO:BI fields. */ +#define PPC_BCC_SHORT(cond, dest) \ + do { \ + long offset = (long)(dest) - (ctx->idx * 4); \ + if (!is_offset_in_cond_branch_range(offset)) { \ + pr_err_ratelimited("Conditional branch offset 0x%lx (@%u) out of range\n", offset, ctx->idx); \ + return -ERANGE; \ + } \ + EMIT(PPC_INST_BRANCH_COND | (((cond) & 0x3ff) << 16) | (offset & 0xfffc)); \ + } while (0) + +/* Sign-extended 32-bit immediate load */ +#define PPC_LI32(d, i) do { \ + if ((int)(uintptr_t)(i) >= -32768 && \ + (int)(uintptr_t)(i) < 32768) \ + PPC_LI(d, i); \ + else { \ + PPC_LIS(d, IMM_H(i)); \ + if (IMM_L(i)) \ + PPC_ORI(d, d, IMM_L(i)); \ + } } while(0) + +#define PPC_LI64(d, i) do { \ + if ((long)(i) >= -2147483648 && \ + (long)(i) < 2147483648) \ + PPC_LI32(d, i); \ + else { \ + if (!((uintptr_t)(i) & 0xffff800000000000ULL)) \ + PPC_LI(d, ((uintptr_t)(i) >> 32) & 0xffff); \ + else { \ + PPC_LIS(d, ((uintptr_t)(i) >> 48)); \ + if ((uintptr_t)(i) & 0x0000ffff00000000ULL) \ + PPC_ORI(d, d, \ + ((uintptr_t)(i) >> 32) & 0xffff); \ + } \ + PPC_SLDI(d, d, 32); \ + if ((uintptr_t)(i) & 0x00000000ffff0000ULL) \ + PPC_ORIS(d, d, \ + ((uintptr_t)(i) >> 16) & 0xffff); \ + if ((uintptr_t)(i) & 0x000000000000ffffULL) \ + PPC_ORI(d, d, (uintptr_t)(i) & 0xffff); \ + } } while (0) + +#ifdef CONFIG_PPC64 +#define PPC_FUNC_ADDR(d,i) do { PPC_LI64(d, i); } while(0) +#else +#define PPC_FUNC_ADDR(d,i) do { PPC_LI32(d, i); } while(0) +#endif + +/* + * The fly in the ointment of code size changing from pass to pass is + * avoided by padding the short branch case with a NOP. If code size differs + * with different branch reaches we will have the issue of code moving from + * one pass to the next and will need a few passes to converge on a stable + * state. + */ +#define PPC_BCC(cond, dest) do { \ + if (is_offset_in_cond_branch_range((long)(dest) - (ctx->idx * 4))) { \ + PPC_BCC_SHORT(cond, dest); \ + PPC_NOP(); \ + } else { \ + /* Flip the 'T or F' bit to invert comparison */ \ + PPC_BCC_SHORT(cond ^ COND_CMP_TRUE, (ctx->idx+2)*4); \ + PPC_JMP(dest); \ + } } while(0) + +/* To create a branch condition, select a bit of cr0... */ +#define CR0_LT 0 +#define CR0_GT 1 +#define CR0_EQ 2 +/* ...and modify BO[3] */ +#define COND_CMP_TRUE 0x100 +#define COND_CMP_FALSE 0x000 +/* Together, they make all required comparisons: */ +#define COND_GT (CR0_GT | COND_CMP_TRUE) +#define COND_GE (CR0_LT | COND_CMP_FALSE) +#define COND_EQ (CR0_EQ | COND_CMP_TRUE) +#define COND_NE (CR0_EQ | COND_CMP_FALSE) +#define COND_LT (CR0_LT | COND_CMP_TRUE) +#define COND_LE (CR0_GT | COND_CMP_FALSE) + +#endif + +#endif diff --git a/arch/powerpc/net/bpf_jit32.h b/arch/powerpc/net/bpf_jit32.h new file mode 100644 index 000000000..ade045477 --- /dev/null +++ b/arch/powerpc/net/bpf_jit32.h @@ -0,0 +1,144 @@ +/* + * bpf_jit32.h: BPF JIT compiler for PPC + * + * Copyright 2011 Matt Evans <matt@ozlabs.org>, IBM Corporation + * + * Split from bpf_jit.h + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; version 2 + * of the License. + */ +#ifndef _BPF_JIT32_H +#define _BPF_JIT32_H + +#include <asm/asm-compat.h> +#include "bpf_jit.h" + +#ifdef CONFIG_PPC64 +#define BPF_PPC_STACK_R3_OFF 48 +#define BPF_PPC_STACK_LOCALS 32 +#define BPF_PPC_STACK_BASIC (48+64) +#define BPF_PPC_STACK_SAVE (18*8) +#define BPF_PPC_STACKFRAME (BPF_PPC_STACK_BASIC+BPF_PPC_STACK_LOCALS+ \ + BPF_PPC_STACK_SAVE) +#define BPF_PPC_SLOWPATH_FRAME (48+64) +#else +#define BPF_PPC_STACK_R3_OFF 24 +#define BPF_PPC_STACK_LOCALS 16 +#define BPF_PPC_STACK_BASIC (24+32) +#define BPF_PPC_STACK_SAVE (18*4) +#define BPF_PPC_STACKFRAME (BPF_PPC_STACK_BASIC+BPF_PPC_STACK_LOCALS+ \ + BPF_PPC_STACK_SAVE) +#define BPF_PPC_SLOWPATH_FRAME (24+32) +#endif + +#define REG_SZ (BITS_PER_LONG/8) + +/* + * Generated code register usage: + * + * As normal PPC C ABI (e.g. r1=sp, r2=TOC), with: + * + * skb r3 (Entry parameter) + * A register r4 + * X register r5 + * addr param r6 + * r7-r10 scratch + * skb->data r14 + * skb headlen r15 (skb->len - skb->data_len) + * m[0] r16 + * m[...] ... + * m[15] r31 + */ +#define r_skb 3 +#define r_ret 3 +#define r_A 4 +#define r_X 5 +#define r_addr 6 +#define r_scratch1 7 +#define r_scratch2 8 +#define r_D 14 +#define r_HL 15 +#define r_M 16 + +#ifndef __ASSEMBLY__ + +/* + * Assembly helpers from arch/powerpc/net/bpf_jit.S: + */ +#define DECLARE_LOAD_FUNC(func) \ + extern u8 func[], func##_negative_offset[], func##_positive_offset[] + +DECLARE_LOAD_FUNC(sk_load_word); +DECLARE_LOAD_FUNC(sk_load_half); +DECLARE_LOAD_FUNC(sk_load_byte); +DECLARE_LOAD_FUNC(sk_load_byte_msh); + +#define PPC_LBZ_OFFS(r, base, i) do { if ((i) < 32768) PPC_LBZ(r, base, i); \ + else { PPC_ADDIS(r, base, IMM_HA(i)); \ + PPC_LBZ(r, r, IMM_L(i)); } } while(0) + +#define PPC_LD_OFFS(r, base, i) do { if ((i) < 32768) PPC_LD(r, base, i); \ + else { PPC_ADDIS(r, base, IMM_HA(i)); \ + PPC_LD(r, r, IMM_L(i)); } } while(0) + +#define PPC_LWZ_OFFS(r, base, i) do { if ((i) < 32768) PPC_LWZ(r, base, i); \ + else { PPC_ADDIS(r, base, IMM_HA(i)); \ + PPC_LWZ(r, r, IMM_L(i)); } } while(0) + +#define PPC_LHZ_OFFS(r, base, i) do { if ((i) < 32768) PPC_LHZ(r, base, i); \ + else { PPC_ADDIS(r, base, IMM_HA(i)); \ + PPC_LHZ(r, r, IMM_L(i)); } } while(0) + +#ifdef CONFIG_PPC64 +#define PPC_LL_OFFS(r, base, i) do { PPC_LD_OFFS(r, base, i); } while(0) +#else +#define PPC_LL_OFFS(r, base, i) do { PPC_LWZ_OFFS(r, base, i); } while(0) +#endif + +#ifdef CONFIG_SMP +#ifdef CONFIG_PPC64 +#define PPC_BPF_LOAD_CPU(r) \ + do { BUILD_BUG_ON(FIELD_SIZEOF(struct paca_struct, paca_index) != 2); \ + PPC_LHZ_OFFS(r, 13, offsetof(struct paca_struct, paca_index)); \ + } while (0) +#else +#define PPC_BPF_LOAD_CPU(r) \ + do { BUILD_BUG_ON(FIELD_SIZEOF(struct thread_info, cpu) != 4); \ + PPC_LHZ_OFFS(r, (1 & ~(THREAD_SIZE - 1)), \ + offsetof(struct thread_info, cpu)); \ + } while(0) +#endif +#else +#define PPC_BPF_LOAD_CPU(r) do { PPC_LI(r, 0); } while(0) +#endif + +#define PPC_LHBRX_OFFS(r, base, i) \ + do { PPC_LI32(r, i); PPC_LHBRX(r, r, base); } while(0) +#ifdef __LITTLE_ENDIAN__ +#define PPC_NTOHS_OFFS(r, base, i) PPC_LHBRX_OFFS(r, base, i) +#else +#define PPC_NTOHS_OFFS(r, base, i) PPC_LHZ_OFFS(r, base, i) +#endif + +#define PPC_BPF_LL(r, base, i) do { PPC_LWZ(r, base, i); } while(0) +#define PPC_BPF_STL(r, base, i) do { PPC_STW(r, base, i); } while(0) +#define PPC_BPF_STLU(r, base, i) do { PPC_STWU(r, base, i); } while(0) + +#define SEEN_DATAREF 0x10000 /* might call external helpers */ +#define SEEN_XREG 0x20000 /* X reg is used */ +#define SEEN_MEM 0x40000 /* SEEN_MEM+(1<<n) = use mem[n] for temporary + * storage */ +#define SEEN_MEM_MSK 0x0ffff + +struct codegen_context { + unsigned int seen; + unsigned int idx; + int pc_ret0; /* bpf index of first RET #0 instruction (if any) */ +}; + +#endif + +#endif diff --git a/arch/powerpc/net/bpf_jit64.h b/arch/powerpc/net/bpf_jit64.h new file mode 100644 index 000000000..61ed9a4b2 --- /dev/null +++ b/arch/powerpc/net/bpf_jit64.h @@ -0,0 +1,112 @@ +/* + * bpf_jit64.h: BPF JIT compiler for PPC64 + * + * Copyright 2016 Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> + * IBM Corporation + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; version 2 + * of the License. + */ +#ifndef _BPF_JIT64_H +#define _BPF_JIT64_H + +#include "bpf_jit.h" + +/* + * Stack layout: + * Ensure the top half (upto local_tmp_var) stays consistent + * with our redzone usage. + * + * [ prev sp ] <------------- + * [ nv gpr save area ] 5*8 | + * [ tail_call_cnt ] 8 | + * [ local_tmp_var ] 16 | + * fp (r31) --> [ ebpf stack space ] upto 512 | + * [ frame header ] 32/112 | + * sp (r1) ---> [ stack pointer ] -------------- + */ + +/* for gpr non volatile registers BPG_REG_6 to 10 */ +#define BPF_PPC_STACK_SAVE (5*8) +/* for bpf JIT code internal usage */ +#define BPF_PPC_STACK_LOCALS 24 +/* stack frame excluding BPF stack, ensure this is quadword aligned */ +#define BPF_PPC_STACKFRAME (STACK_FRAME_MIN_SIZE + \ + BPF_PPC_STACK_LOCALS + BPF_PPC_STACK_SAVE) + +#ifndef __ASSEMBLY__ + +/* BPF register usage */ +#define TMP_REG_1 (MAX_BPF_JIT_REG + 0) +#define TMP_REG_2 (MAX_BPF_JIT_REG + 1) + +/* BPF to ppc register mappings */ +static const int b2p[] = { + /* function return value */ + [BPF_REG_0] = 8, + /* function arguments */ + [BPF_REG_1] = 3, + [BPF_REG_2] = 4, + [BPF_REG_3] = 5, + [BPF_REG_4] = 6, + [BPF_REG_5] = 7, + /* non volatile registers */ + [BPF_REG_6] = 27, + [BPF_REG_7] = 28, + [BPF_REG_8] = 29, + [BPF_REG_9] = 30, + /* frame pointer aka BPF_REG_10 */ + [BPF_REG_FP] = 31, + /* eBPF jit internal registers */ + [BPF_REG_AX] = 2, + [TMP_REG_1] = 9, + [TMP_REG_2] = 10 +}; + +/* PPC NVR range -- update this if we ever use NVRs below r27 */ +#define BPF_PPC_NVR_MIN 27 + +/* + * WARNING: These can use TMP_REG_2 if the offset is not at word boundary, + * so ensure that it isn't in use already. + */ +#define PPC_BPF_LL(r, base, i) do { \ + if ((i) % 4) { \ + PPC_LI(b2p[TMP_REG_2], (i)); \ + PPC_LDX(r, base, b2p[TMP_REG_2]); \ + } else \ + PPC_LD(r, base, i); \ + } while(0) +#define PPC_BPF_STL(r, base, i) do { \ + if ((i) % 4) { \ + PPC_LI(b2p[TMP_REG_2], (i)); \ + PPC_STDX(r, base, b2p[TMP_REG_2]); \ + } else \ + PPC_STD(r, base, i); \ + } while(0) +#define PPC_BPF_STLU(r, base, i) do { PPC_STDU(r, base, i); } while(0) + +#define SEEN_FUNC 0x1000 /* might call external helpers */ +#define SEEN_STACK 0x2000 /* uses BPF stack */ +#define SEEN_TAILCALL 0x4000 /* uses tail calls */ + +struct codegen_context { + /* + * This is used to track register usage as well + * as calls to external helpers. + * - register usage is tracked with corresponding + * bits (r3-r10 and r27-r31) + * - rest of the bits can be used to track other + * things -- for now, we use bits 16 to 23 + * encoded in SEEN_* macros above + */ + unsigned int seen; + unsigned int idx; + unsigned int stack_size; +}; + +#endif /* !__ASSEMBLY__ */ + +#endif diff --git a/arch/powerpc/net/bpf_jit_asm.S b/arch/powerpc/net/bpf_jit_asm.S new file mode 100644 index 000000000..c80280dc2 --- /dev/null +++ b/arch/powerpc/net/bpf_jit_asm.S @@ -0,0 +1,230 @@ +/* bpf_jit.S: Packet/header access helper functions + * for PPC64 BPF compiler. + * + * Copyright 2011 Matt Evans <matt@ozlabs.org>, IBM Corporation + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; version 2 + * of the License. + */ + +#include <asm/ppc_asm.h> +#include <asm/asm-compat.h> +#include "bpf_jit32.h" + +/* + * All of these routines are called directly from generated code, + * whose register usage is: + * + * r3 skb + * r4,r5 A,X + * r6 *** address parameter to helper *** + * r7-r10 scratch + * r14 skb->data + * r15 skb headlen + * r16-31 M[] + */ + +/* + * To consider: These helpers are so small it could be better to just + * generate them inline. Inline code can do the simple headlen check + * then branch directly to slow_path_XXX if required. (In fact, could + * load a spare GPR with the address of slow_path_generic and pass size + * as an argument, making the call site a mtlr, li and bllr.) + */ + .globl sk_load_word +sk_load_word: + PPC_LCMPI r_addr, 0 + blt bpf_slow_path_word_neg + .globl sk_load_word_positive_offset +sk_load_word_positive_offset: + /* Are we accessing past headlen? */ + subi r_scratch1, r_HL, 4 + PPC_LCMP r_scratch1, r_addr + blt bpf_slow_path_word + /* Nope, just hitting the header. cr0 here is eq or gt! */ +#ifdef __LITTLE_ENDIAN__ + lwbrx r_A, r_D, r_addr +#else + lwzx r_A, r_D, r_addr +#endif + blr /* Return success, cr0 != LT */ + + .globl sk_load_half +sk_load_half: + PPC_LCMPI r_addr, 0 + blt bpf_slow_path_half_neg + .globl sk_load_half_positive_offset +sk_load_half_positive_offset: + subi r_scratch1, r_HL, 2 + PPC_LCMP r_scratch1, r_addr + blt bpf_slow_path_half +#ifdef __LITTLE_ENDIAN__ + lhbrx r_A, r_D, r_addr +#else + lhzx r_A, r_D, r_addr +#endif + blr + + .globl sk_load_byte +sk_load_byte: + PPC_LCMPI r_addr, 0 + blt bpf_slow_path_byte_neg + .globl sk_load_byte_positive_offset +sk_load_byte_positive_offset: + PPC_LCMP r_HL, r_addr + ble bpf_slow_path_byte + lbzx r_A, r_D, r_addr + blr + +/* + * BPF_LDX | BPF_B | BPF_MSH: ldxb 4*([offset]&0xf) + * r_addr is the offset value + */ + .globl sk_load_byte_msh +sk_load_byte_msh: + PPC_LCMPI r_addr, 0 + blt bpf_slow_path_byte_msh_neg + .globl sk_load_byte_msh_positive_offset +sk_load_byte_msh_positive_offset: + PPC_LCMP r_HL, r_addr + ble bpf_slow_path_byte_msh + lbzx r_X, r_D, r_addr + rlwinm r_X, r_X, 2, 32-4-2, 31-2 + blr + +/* Call out to skb_copy_bits: + * We'll need to back up our volatile regs first; we have + * local variable space at r1+(BPF_PPC_STACK_BASIC). + * Allocate a new stack frame here to remain ABI-compliant in + * stashing LR. + */ +#define bpf_slow_path_common(SIZE) \ + mflr r0; \ + PPC_STL r0, PPC_LR_STKOFF(r1); \ + /* R3 goes in parameter space of caller's frame */ \ + PPC_STL r_skb, (BPF_PPC_STACKFRAME+BPF_PPC_STACK_R3_OFF)(r1); \ + PPC_STL r_A, (BPF_PPC_STACK_BASIC+(0*REG_SZ))(r1); \ + PPC_STL r_X, (BPF_PPC_STACK_BASIC+(1*REG_SZ))(r1); \ + addi r5, r1, BPF_PPC_STACK_BASIC+(2*REG_SZ); \ + PPC_STLU r1, -BPF_PPC_SLOWPATH_FRAME(r1); \ + /* R3 = r_skb, as passed */ \ + mr r4, r_addr; \ + li r6, SIZE; \ + bl skb_copy_bits; \ + nop; \ + /* R3 = 0 on success */ \ + addi r1, r1, BPF_PPC_SLOWPATH_FRAME; \ + PPC_LL r0, PPC_LR_STKOFF(r1); \ + PPC_LL r_A, (BPF_PPC_STACK_BASIC+(0*REG_SZ))(r1); \ + PPC_LL r_X, (BPF_PPC_STACK_BASIC+(1*REG_SZ))(r1); \ + mtlr r0; \ + PPC_LCMPI r3, 0; \ + blt bpf_error; /* cr0 = LT */ \ + PPC_LL r_skb, (BPF_PPC_STACKFRAME+BPF_PPC_STACK_R3_OFF)(r1); \ + /* Great success! */ + +bpf_slow_path_word: + bpf_slow_path_common(4) + /* Data value is on stack, and cr0 != LT */ + lwz r_A, BPF_PPC_STACK_BASIC+(2*REG_SZ)(r1) + blr + +bpf_slow_path_half: + bpf_slow_path_common(2) + lhz r_A, BPF_PPC_STACK_BASIC+(2*8)(r1) + blr + +bpf_slow_path_byte: + bpf_slow_path_common(1) + lbz r_A, BPF_PPC_STACK_BASIC+(2*8)(r1) + blr + +bpf_slow_path_byte_msh: + bpf_slow_path_common(1) + lbz r_X, BPF_PPC_STACK_BASIC+(2*8)(r1) + rlwinm r_X, r_X, 2, 32-4-2, 31-2 + blr + +/* Call out to bpf_internal_load_pointer_neg_helper: + * We'll need to back up our volatile regs first; we have + * local variable space at r1+(BPF_PPC_STACK_BASIC). + * Allocate a new stack frame here to remain ABI-compliant in + * stashing LR. + */ +#define sk_negative_common(SIZE) \ + mflr r0; \ + PPC_STL r0, PPC_LR_STKOFF(r1); \ + /* R3 goes in parameter space of caller's frame */ \ + PPC_STL r_skb, (BPF_PPC_STACKFRAME+BPF_PPC_STACK_R3_OFF)(r1); \ + PPC_STL r_A, (BPF_PPC_STACK_BASIC+(0*REG_SZ))(r1); \ + PPC_STL r_X, (BPF_PPC_STACK_BASIC+(1*REG_SZ))(r1); \ + PPC_STLU r1, -BPF_PPC_SLOWPATH_FRAME(r1); \ + /* R3 = r_skb, as passed */ \ + mr r4, r_addr; \ + li r5, SIZE; \ + bl bpf_internal_load_pointer_neg_helper; \ + nop; \ + /* R3 != 0 on success */ \ + addi r1, r1, BPF_PPC_SLOWPATH_FRAME; \ + PPC_LL r0, PPC_LR_STKOFF(r1); \ + PPC_LL r_A, (BPF_PPC_STACK_BASIC+(0*REG_SZ))(r1); \ + PPC_LL r_X, (BPF_PPC_STACK_BASIC+(1*REG_SZ))(r1); \ + mtlr r0; \ + PPC_LCMPLI r3, 0; \ + beq bpf_error_slow; /* cr0 = EQ */ \ + mr r_addr, r3; \ + PPC_LL r_skb, (BPF_PPC_STACKFRAME+BPF_PPC_STACK_R3_OFF)(r1); \ + /* Great success! */ + +bpf_slow_path_word_neg: + lis r_scratch1,-32 /* SKF_LL_OFF */ + PPC_LCMP r_addr, r_scratch1 /* addr < SKF_* */ + blt bpf_error /* cr0 = LT */ + .globl sk_load_word_negative_offset +sk_load_word_negative_offset: + sk_negative_common(4) + lwz r_A, 0(r_addr) + blr + +bpf_slow_path_half_neg: + lis r_scratch1,-32 /* SKF_LL_OFF */ + PPC_LCMP r_addr, r_scratch1 /* addr < SKF_* */ + blt bpf_error /* cr0 = LT */ + .globl sk_load_half_negative_offset +sk_load_half_negative_offset: + sk_negative_common(2) + lhz r_A, 0(r_addr) + blr + +bpf_slow_path_byte_neg: + lis r_scratch1,-32 /* SKF_LL_OFF */ + PPC_LCMP r_addr, r_scratch1 /* addr < SKF_* */ + blt bpf_error /* cr0 = LT */ + .globl sk_load_byte_negative_offset +sk_load_byte_negative_offset: + sk_negative_common(1) + lbz r_A, 0(r_addr) + blr + +bpf_slow_path_byte_msh_neg: + lis r_scratch1,-32 /* SKF_LL_OFF */ + PPC_LCMP r_addr, r_scratch1 /* addr < SKF_* */ + blt bpf_error /* cr0 = LT */ + .globl sk_load_byte_msh_negative_offset +sk_load_byte_msh_negative_offset: + sk_negative_common(1) + lbz r_X, 0(r_addr) + rlwinm r_X, r_X, 2, 32-4-2, 31-2 + blr + +bpf_error_slow: + /* fabricate a cr0 = lt */ + li r_scratch1, -1 + PPC_LCMPI r_scratch1, 0 +bpf_error: + /* Entered with cr0 = lt */ + li r3, 0 + /* Generated code will 'blt epilogue', returning 0. */ + blr diff --git a/arch/powerpc/net/bpf_jit_comp.c b/arch/powerpc/net/bpf_jit_comp.c new file mode 100644 index 000000000..d5bfe24bb --- /dev/null +++ b/arch/powerpc/net/bpf_jit_comp.c @@ -0,0 +1,689 @@ +/* bpf_jit_comp.c: BPF JIT compiler + * + * Copyright 2011 Matt Evans <matt@ozlabs.org>, IBM Corporation + * + * Based on the x86 BPF compiler, by Eric Dumazet (eric.dumazet@gmail.com) + * Ported to ppc32 by Denis Kirjanov <kda@linux-powerpc.org> + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; version 2 + * of the License. + */ +#include <linux/moduleloader.h> +#include <asm/cacheflush.h> +#include <asm/asm-compat.h> +#include <linux/netdevice.h> +#include <linux/filter.h> +#include <linux/if_vlan.h> + +#include "bpf_jit32.h" + +static inline void bpf_flush_icache(void *start, void *end) +{ + smp_wmb(); + flush_icache_range((unsigned long)start, (unsigned long)end); +} + +static void bpf_jit_build_prologue(struct bpf_prog *fp, u32 *image, + struct codegen_context *ctx) +{ + int i; + const struct sock_filter *filter = fp->insns; + + if (ctx->seen & (SEEN_MEM | SEEN_DATAREF)) { + /* Make stackframe */ + if (ctx->seen & SEEN_DATAREF) { + /* If we call any helpers (for loads), save LR */ + EMIT(PPC_INST_MFLR | __PPC_RT(R0)); + PPC_BPF_STL(0, 1, PPC_LR_STKOFF); + + /* Back up non-volatile regs. */ + PPC_BPF_STL(r_D, 1, -(REG_SZ*(32-r_D))); + PPC_BPF_STL(r_HL, 1, -(REG_SZ*(32-r_HL))); + } + if (ctx->seen & SEEN_MEM) { + /* + * Conditionally save regs r15-r31 as some will be used + * for M[] data. + */ + for (i = r_M; i < (r_M+16); i++) { + if (ctx->seen & (1 << (i-r_M))) + PPC_BPF_STL(i, 1, -(REG_SZ*(32-i))); + } + } + PPC_BPF_STLU(1, 1, -BPF_PPC_STACKFRAME); + } + + if (ctx->seen & SEEN_DATAREF) { + /* + * If this filter needs to access skb data, + * prepare r_D and r_HL: + * r_HL = skb->len - skb->data_len + * r_D = skb->data + */ + PPC_LWZ_OFFS(r_scratch1, r_skb, offsetof(struct sk_buff, + data_len)); + PPC_LWZ_OFFS(r_HL, r_skb, offsetof(struct sk_buff, len)); + PPC_SUB(r_HL, r_HL, r_scratch1); + PPC_LL_OFFS(r_D, r_skb, offsetof(struct sk_buff, data)); + } + + if (ctx->seen & SEEN_XREG) { + /* + * TODO: Could also detect whether first instr. sets X and + * avoid this (as below, with A). + */ + PPC_LI(r_X, 0); + } + + /* make sure we dont leak kernel information to user */ + if (bpf_needs_clear_a(&filter[0])) + PPC_LI(r_A, 0); +} + +static void bpf_jit_build_epilogue(u32 *image, struct codegen_context *ctx) +{ + int i; + + if (ctx->seen & (SEEN_MEM | SEEN_DATAREF)) { + PPC_ADDI(1, 1, BPF_PPC_STACKFRAME); + if (ctx->seen & SEEN_DATAREF) { + PPC_BPF_LL(0, 1, PPC_LR_STKOFF); + PPC_MTLR(0); + PPC_BPF_LL(r_D, 1, -(REG_SZ*(32-r_D))); + PPC_BPF_LL(r_HL, 1, -(REG_SZ*(32-r_HL))); + } + if (ctx->seen & SEEN_MEM) { + /* Restore any saved non-vol registers */ + for (i = r_M; i < (r_M+16); i++) { + if (ctx->seen & (1 << (i-r_M))) + PPC_BPF_LL(i, 1, -(REG_SZ*(32-i))); + } + } + } + /* The RETs have left a return value in R3. */ + + PPC_BLR(); +} + +#define CHOOSE_LOAD_FUNC(K, func) \ + ((int)K < 0 ? ((int)K >= SKF_LL_OFF ? func##_negative_offset : func) : func##_positive_offset) + +/* 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_MULW(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_MULW(r_A, r_A, r_scratch1); + } + break; + case BPF_ALU | BPF_MOD | BPF_X: /* A %= X; */ + 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 { + PPC_BCC_SHORT(COND_NE, (ctx->idx*4)+12); + PPC_LI(r_ret, 0); + PPC_JMP(exit_addr); + } + if (code == (BPF_ALU | BPF_MOD | BPF_X)) { + PPC_DIVWU(r_scratch1, r_A, r_X); + PPC_MULW(r_scratch1, r_X, r_scratch1); + PPC_SUB(r_A, r_A, r_scratch1); + } else { + PPC_DIVWU(r_A, r_A, r_X); + } + break; + case BPF_ALU | BPF_MOD | BPF_K: /* A %= K; */ + PPC_LI32(r_scratch2, K); + PPC_DIVWU(r_scratch1, r_A, r_scratch2); + PPC_MULW(r_scratch1, r_scratch2, r_scratch1); + PPC_SUB(r_A, r_A, r_scratch1); + 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_ABS: /* A = *((u32 *)(seccomp_data + K)); */ + PPC_LWZ_OFFS(r_A, r_skb, K); + 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: + case BPF_ANC | SKF_AD_HATYPE: + BUILD_BUG_ON(FIELD_SIZEOF(struct net_device, + ifindex) != 4); + BUILD_BUG_ON(FIELD_SIZEOF(struct net_device, + type) != 2); + PPC_LL_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); + } + if (code == (BPF_ANC | SKF_AD_IFINDEX)) { + PPC_LWZ_OFFS(r_A, r_scratch1, + offsetof(struct net_device, ifindex)); + } else { + PPC_LHZ_OFFS(r_A, r_scratch1, + offsetof(struct net_device, type)); + } + + 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_PKTTYPE: + PPC_LBZ_OFFS(r_A, r_skb, PKT_TYPE_OFFSET()); + PPC_ANDI(r_A, r_A, PKT_TYPE_MAX); + PPC_SRWI(r_A, r_A, 5); + break; + case BPF_ANC | SKF_AD_CPU: + PPC_BPF_LOAD_CPU(r_A); + 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_FUNC_ADDR(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_FUNC_ADDR(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; +} + +void bpf_jit_compile(struct bpf_prog *fp) +{ + unsigned int proglen; + unsigned int alloclen; + u32 *image = NULL; + u32 *code_base; + unsigned int *addrs; + struct codegen_context cgctx; + int pass; + int flen = fp->len; + + if (!bpf_jit_enable) + return; + + addrs = kcalloc(flen + 1, sizeof(*addrs), GFP_KERNEL); + if (addrs == NULL) + return; + + /* + * There are multiple assembly passes as the generated code will change + * size as it settles down, figuring out the max branch offsets/exit + * paths required. + * + * The range of standard conditional branches is +/- 32Kbytes. Since + * BPF_MAXINSNS = 4096, we can only jump from (worst case) start to + * finish with 8 bytes/instruction. Not feasible, so long jumps are + * used, distinct from short branches. + * + * Current: + * + * For now, both branch types assemble to 2 words (short branches padded + * with a NOP); this is less efficient, but assembly will always complete + * after exactly 3 passes: + * + * First pass: No code buffer; Program is "faux-generated" -- no code + * emitted but maximum size of output determined (and addrs[] filled + * in). Also, we note whether we use M[], whether we use skb data, etc. + * All generation choices assumed to be 'worst-case', e.g. branches all + * far (2 instructions), return path code reduction not available, etc. + * + * Second pass: Code buffer allocated with size determined previously. + * Prologue generated to support features we have seen used. Exit paths + * determined and addrs[] is filled in again, as code may be slightly + * smaller as a result. + * + * Third pass: Code generated 'for real', and branch destinations + * determined from now-accurate addrs[] map. + * + * Ideal: + * + * If we optimise this, near branches will be shorter. On the + * first assembly pass, we should err on the side of caution and + * generate the biggest code. On subsequent passes, branches will be + * generated short or long and code size will reduce. With smaller + * code, more branches may fall into the short category, and code will + * reduce more. + * + * Finally, if we see one pass generate code the same size as the + * previous pass we have converged and should now generate code for + * real. Allocating at the end will also save the memory that would + * otherwise be wasted by the (small) current code shrinkage. + * Preferably, we should do a small number of passes (e.g. 5) and if we + * haven't converged by then, get impatient and force code to generate + * as-is, even if the odd branch would be left long. The chances of a + * long jump are tiny with all but the most enormous of BPF filter + * inputs, so we should usually converge on the third pass. + */ + + cgctx.idx = 0; + cgctx.seen = 0; + cgctx.pc_ret0 = -1; + /* Scouting faux-generate pass 0 */ + if (bpf_jit_build_body(fp, 0, &cgctx, addrs)) + /* We hit something illegal or unsupported. */ + goto out; + + /* + * Pretend to build prologue, given the features we've seen. This will + * update ctgtx.idx as it pretends to output instructions, then we can + * calculate total size from idx. + */ + bpf_jit_build_prologue(fp, 0, &cgctx); + bpf_jit_build_epilogue(0, &cgctx); + + proglen = cgctx.idx * 4; + alloclen = proglen + FUNCTION_DESCR_SIZE; + image = module_alloc(alloclen); + if (!image) + goto out; + + code_base = image + (FUNCTION_DESCR_SIZE/4); + + /* Code generation passes 1-2 */ + for (pass = 1; pass < 3; pass++) { + /* Now build the prologue, body code & epilogue for real. */ + cgctx.idx = 0; + bpf_jit_build_prologue(fp, code_base, &cgctx); + bpf_jit_build_body(fp, code_base, &cgctx, addrs); + bpf_jit_build_epilogue(code_base, &cgctx); + + if (bpf_jit_enable > 1) + pr_info("Pass %d: shrink = %d, seen = 0x%x\n", pass, + proglen - (cgctx.idx * 4), cgctx.seen); + } + + if (bpf_jit_enable > 1) + /* Note that we output the base address of the code_base + * rather than image, since opcodes are in code_base. + */ + bpf_jit_dump(flen, proglen, pass, code_base); + + bpf_flush_icache(code_base, code_base + (proglen/4)); + +#ifdef CONFIG_PPC64 + /* Function descriptor nastiness: Address + TOC */ + ((u64 *)image)[0] = (u64)code_base; + ((u64 *)image)[1] = local_paca->kernel_toc; +#endif + + fp->bpf_func = (void *)image; + fp->jited = 1; + +out: + kfree(addrs); + return; +} + +void bpf_jit_free(struct bpf_prog *fp) +{ + if (fp->jited) + module_memfree(fp->bpf_func); + + bpf_prog_unlock_free(fp); +} diff --git a/arch/powerpc/net/bpf_jit_comp64.c b/arch/powerpc/net/bpf_jit_comp64.c new file mode 100644 index 000000000..7b1fdcd4d --- /dev/null +++ b/arch/powerpc/net/bpf_jit_comp64.c @@ -0,0 +1,1118 @@ +/* + * bpf_jit_comp64.c: eBPF JIT compiler + * + * Copyright 2016 Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> + * IBM Corporation + * + * Based on the powerpc classic BPF JIT compiler by Matt Evans + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; version 2 + * of the License. + */ +#include <linux/moduleloader.h> +#include <asm/cacheflush.h> +#include <asm/asm-compat.h> +#include <linux/netdevice.h> +#include <linux/filter.h> +#include <linux/if_vlan.h> +#include <asm/kprobes.h> +#include <linux/bpf.h> +#include <asm/security_features.h> + +#include "bpf_jit64.h" + +static void bpf_jit_fill_ill_insns(void *area, unsigned int size) +{ + memset32(area, BREAKPOINT_INSTRUCTION, size/4); +} + +static inline void bpf_flush_icache(void *start, void *end) +{ + smp_wmb(); + flush_icache_range((unsigned long)start, (unsigned long)end); +} + +static inline bool bpf_is_seen_register(struct codegen_context *ctx, int i) +{ + return (ctx->seen & (1 << (31 - b2p[i]))); +} + +static inline void bpf_set_seen_register(struct codegen_context *ctx, int i) +{ + ctx->seen |= (1 << (31 - b2p[i])); +} + +static inline bool bpf_has_stack_frame(struct codegen_context *ctx) +{ + /* + * We only need a stack frame if: + * - we call other functions (kernel helpers), or + * - the bpf program uses its stack area + * The latter condition is deduced from the usage of BPF_REG_FP + */ + return ctx->seen & SEEN_FUNC || bpf_is_seen_register(ctx, BPF_REG_FP); +} + +/* + * When not setting up our own stackframe, the redzone usage is: + * + * [ prev sp ] <------------- + * [ ... ] | + * sp (r1) ---> [ stack pointer ] -------------- + * [ nv gpr save area ] 5*8 + * [ tail_call_cnt ] 8 + * [ local_tmp_var ] 16 + * [ unused red zone ] 208 bytes protected + */ +static int bpf_jit_stack_local(struct codegen_context *ctx) +{ + if (bpf_has_stack_frame(ctx)) + return STACK_FRAME_MIN_SIZE + ctx->stack_size; + else + return -(BPF_PPC_STACK_SAVE + 24); +} + +static int bpf_jit_stack_tailcallcnt(struct codegen_context *ctx) +{ + return bpf_jit_stack_local(ctx) + 16; +} + +static int bpf_jit_stack_offsetof(struct codegen_context *ctx, int reg) +{ + if (reg >= BPF_PPC_NVR_MIN && reg < 32) + return (bpf_has_stack_frame(ctx) ? + (BPF_PPC_STACKFRAME + ctx->stack_size) : 0) + - (8 * (32 - reg)); + + pr_err("BPF JIT is asking about unknown registers"); + BUG(); +} + +static void bpf_jit_build_prologue(u32 *image, struct codegen_context *ctx) +{ + int i; + + /* + * Initialize tail_call_cnt if we do tail calls. + * Otherwise, put in NOPs so that it can be skipped when we are + * invoked through a tail call. + */ + if (ctx->seen & SEEN_TAILCALL) { + PPC_LI(b2p[TMP_REG_1], 0); + /* this goes in the redzone */ + PPC_BPF_STL(b2p[TMP_REG_1], 1, -(BPF_PPC_STACK_SAVE + 8)); + } else { + PPC_NOP(); + PPC_NOP(); + } + +#define BPF_TAILCALL_PROLOGUE_SIZE 8 + + if (bpf_has_stack_frame(ctx)) { + /* + * We need a stack frame, but we don't necessarily need to + * save/restore LR unless we call other functions + */ + if (ctx->seen & SEEN_FUNC) { + EMIT(PPC_INST_MFLR | __PPC_RT(R0)); + PPC_BPF_STL(0, 1, PPC_LR_STKOFF); + } + + PPC_BPF_STLU(1, 1, -(BPF_PPC_STACKFRAME + ctx->stack_size)); + } + + /* + * Back up non-volatile regs -- BPF registers 6-10 + * If we haven't created our own stack frame, we save these + * in the protected zone below the previous stack frame + */ + for (i = BPF_REG_6; i <= BPF_REG_10; i++) + if (bpf_is_seen_register(ctx, i)) + PPC_BPF_STL(b2p[i], 1, bpf_jit_stack_offsetof(ctx, b2p[i])); + + /* Setup frame pointer to point to the bpf stack area */ + if (bpf_is_seen_register(ctx, BPF_REG_FP)) + PPC_ADDI(b2p[BPF_REG_FP], 1, + STACK_FRAME_MIN_SIZE + ctx->stack_size); +} + +static void bpf_jit_emit_common_epilogue(u32 *image, struct codegen_context *ctx) +{ + int i; + + /* Restore NVRs */ + for (i = BPF_REG_6; i <= BPF_REG_10; i++) + if (bpf_is_seen_register(ctx, i)) + PPC_BPF_LL(b2p[i], 1, bpf_jit_stack_offsetof(ctx, b2p[i])); + + /* Tear down our stack frame */ + if (bpf_has_stack_frame(ctx)) { + PPC_ADDI(1, 1, BPF_PPC_STACKFRAME + ctx->stack_size); + if (ctx->seen & SEEN_FUNC) { + PPC_BPF_LL(0, 1, PPC_LR_STKOFF); + PPC_MTLR(0); + } + } +} + +static void bpf_jit_build_epilogue(u32 *image, struct codegen_context *ctx) +{ + bpf_jit_emit_common_epilogue(image, ctx); + + /* Move result to r3 */ + PPC_MR(3, b2p[BPF_REG_0]); + + PPC_BLR(); +} + +static void bpf_jit_emit_func_call(u32 *image, struct codegen_context *ctx, u64 func) +{ + unsigned int i, ctx_idx = ctx->idx; + + /* Load function address into r12 */ + PPC_LI64(12, func); + + /* For bpf-to-bpf function calls, the callee's address is unknown + * until the last extra pass. As seen above, we use PPC_LI64() to + * load the callee's address, but this may optimize the number of + * instructions required based on the nature of the address. + * + * Since we don't want the number of instructions emitted to change, + * we pad the optimized PPC_LI64() call with NOPs to guarantee that + * we always have a five-instruction sequence, which is the maximum + * that PPC_LI64() can emit. + */ + for (i = ctx->idx - ctx_idx; i < 5; i++) + PPC_NOP(); + +#ifdef PPC64_ELF_ABI_v1 + /* + * Load TOC from function descriptor at offset 8. + * We can clobber r2 since we get called through a + * function pointer (so caller will save/restore r2) + * and since we don't use a TOC ourself. + */ + PPC_BPF_LL(2, 12, 8); + /* Load actual entry point from function descriptor */ + PPC_BPF_LL(12, 12, 0); +#endif + + PPC_MTLR(12); + PPC_BLRL(); +} + +static int bpf_jit_emit_tail_call(u32 *image, struct codegen_context *ctx, u32 out) +{ + /* + * By now, the eBPF program has already setup parameters in r3, r4 and r5 + * r3/BPF_REG_1 - pointer to ctx -- passed as is to the next bpf program + * r4/BPF_REG_2 - pointer to bpf_array + * r5/BPF_REG_3 - index in bpf_array + */ + int b2p_bpf_array = b2p[BPF_REG_2]; + int b2p_index = b2p[BPF_REG_3]; + + /* + * if (index >= array->map.max_entries) + * goto out; + */ + PPC_LWZ(b2p[TMP_REG_1], b2p_bpf_array, offsetof(struct bpf_array, map.max_entries)); + PPC_RLWINM(b2p_index, b2p_index, 0, 0, 31); + PPC_CMPLW(b2p_index, b2p[TMP_REG_1]); + PPC_BCC(COND_GE, out); + + /* + * if (tail_call_cnt > MAX_TAIL_CALL_CNT) + * goto out; + */ + PPC_BPF_LL(b2p[TMP_REG_1], 1, bpf_jit_stack_tailcallcnt(ctx)); + PPC_CMPLWI(b2p[TMP_REG_1], MAX_TAIL_CALL_CNT); + PPC_BCC(COND_GT, out); + + /* + * tail_call_cnt++; + */ + PPC_ADDI(b2p[TMP_REG_1], b2p[TMP_REG_1], 1); + PPC_BPF_STL(b2p[TMP_REG_1], 1, bpf_jit_stack_tailcallcnt(ctx)); + + /* prog = array->ptrs[index]; */ + PPC_MULI(b2p[TMP_REG_1], b2p_index, 8); + PPC_ADD(b2p[TMP_REG_1], b2p[TMP_REG_1], b2p_bpf_array); + PPC_BPF_LL(b2p[TMP_REG_1], b2p[TMP_REG_1], offsetof(struct bpf_array, ptrs)); + + /* + * if (prog == NULL) + * goto out; + */ + PPC_CMPLDI(b2p[TMP_REG_1], 0); + PPC_BCC(COND_EQ, out); + + /* goto *(prog->bpf_func + prologue_size); */ + PPC_BPF_LL(b2p[TMP_REG_1], b2p[TMP_REG_1], offsetof(struct bpf_prog, bpf_func)); +#ifdef PPC64_ELF_ABI_v1 + /* skip past the function descriptor */ + PPC_ADDI(b2p[TMP_REG_1], b2p[TMP_REG_1], + FUNCTION_DESCR_SIZE + BPF_TAILCALL_PROLOGUE_SIZE); +#else + PPC_ADDI(b2p[TMP_REG_1], b2p[TMP_REG_1], BPF_TAILCALL_PROLOGUE_SIZE); +#endif + PPC_MTCTR(b2p[TMP_REG_1]); + + /* tear down stack, restore NVRs, ... */ + bpf_jit_emit_common_epilogue(image, ctx); + + PPC_BCTR(); + + /* out: */ + return 0; +} + +/* + * We spill into the redzone always, even if the bpf program has its own stackframe. + * Offsets hardcoded based on BPF_PPC_STACK_SAVE -- see bpf_jit_stack_local() + */ +void bpf_stf_barrier(void); + +asm ( +" .global bpf_stf_barrier ;" +" bpf_stf_barrier: ;" +" std 21,-64(1) ;" +" std 22,-56(1) ;" +" sync ;" +" ld 21,-64(1) ;" +" ld 22,-56(1) ;" +" ori 31,31,0 ;" +" .rept 14 ;" +" b 1f ;" +" 1: ;" +" .endr ;" +" blr ;" +); + +/* Assemble the body code between the prologue & epilogue */ +static int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, + struct codegen_context *ctx, + u32 *addrs, bool extra_pass) +{ + enum stf_barrier_type stf_barrier = stf_barrier_type_get(); + const struct bpf_insn *insn = fp->insnsi; + int flen = fp->len; + int i, ret; + + /* Start of epilogue code - will only be valid 2nd pass onwards */ + u32 exit_addr = addrs[flen]; + + for (i = 0; i < flen; i++) { + u32 code = insn[i].code; + u32 dst_reg = b2p[insn[i].dst_reg]; + u32 src_reg = b2p[insn[i].src_reg]; + s16 off = insn[i].off; + s32 imm = insn[i].imm; + u64 imm64; + u8 *func; + u32 true_cond; + u32 tmp_idx; + + /* + * addrs[] maps a BPF bytecode address into a real offset from + * the start of the body code. + */ + addrs[i] = ctx->idx * 4; + + /* + * As an optimization, we note down which non-volatile registers + * are used so that we can only save/restore those in our + * prologue and epilogue. We do this here regardless of whether + * the actual BPF instruction uses src/dst registers or not + * (for instance, BPF_CALL does not use them). The expectation + * is that those instructions will have src_reg/dst_reg set to + * 0. Even otherwise, we just lose some prologue/epilogue + * optimization but everything else should work without + * any issues. + */ + if (dst_reg >= BPF_PPC_NVR_MIN && dst_reg < 32) + bpf_set_seen_register(ctx, insn[i].dst_reg); + if (src_reg >= BPF_PPC_NVR_MIN && src_reg < 32) + bpf_set_seen_register(ctx, insn[i].src_reg); + + switch (code) { + /* + * Arithmetic operations: ADD/SUB/MUL/DIV/MOD/NEG + */ + case BPF_ALU | BPF_ADD | BPF_X: /* (u32) dst += (u32) src */ + case BPF_ALU64 | BPF_ADD | BPF_X: /* dst += src */ + PPC_ADD(dst_reg, dst_reg, src_reg); + goto bpf_alu32_trunc; + case BPF_ALU | BPF_SUB | BPF_X: /* (u32) dst -= (u32) src */ + case BPF_ALU64 | BPF_SUB | BPF_X: /* dst -= src */ + PPC_SUB(dst_reg, dst_reg, src_reg); + goto bpf_alu32_trunc; + case BPF_ALU | BPF_ADD | BPF_K: /* (u32) dst += (u32) imm */ + case BPF_ALU64 | BPF_ADD | BPF_K: /* dst += imm */ + if (!imm) { + goto bpf_alu32_trunc; + } else if (imm >= -32768 && imm < 32768) { + PPC_ADDI(dst_reg, dst_reg, IMM_L(imm)); + } else { + PPC_LI32(b2p[TMP_REG_1], imm); + PPC_ADD(dst_reg, dst_reg, b2p[TMP_REG_1]); + } + goto bpf_alu32_trunc; + case BPF_ALU | BPF_SUB | BPF_K: /* (u32) dst -= (u32) imm */ + case BPF_ALU64 | BPF_SUB | BPF_K: /* dst -= imm */ + if (!imm) { + goto bpf_alu32_trunc; + } else if (imm > -32768 && imm <= 32768) { + PPC_ADDI(dst_reg, dst_reg, IMM_L(-imm)); + } else { + PPC_LI32(b2p[TMP_REG_1], imm); + PPC_SUB(dst_reg, dst_reg, b2p[TMP_REG_1]); + } + goto bpf_alu32_trunc; + case BPF_ALU | BPF_MUL | BPF_X: /* (u32) dst *= (u32) src */ + case BPF_ALU64 | BPF_MUL | BPF_X: /* dst *= src */ + if (BPF_CLASS(code) == BPF_ALU) + PPC_MULW(dst_reg, dst_reg, src_reg); + else + PPC_MULD(dst_reg, dst_reg, src_reg); + goto bpf_alu32_trunc; + case BPF_ALU | BPF_MUL | BPF_K: /* (u32) dst *= (u32) imm */ + case BPF_ALU64 | BPF_MUL | BPF_K: /* dst *= imm */ + if (imm >= -32768 && imm < 32768) + PPC_MULI(dst_reg, dst_reg, IMM_L(imm)); + else { + PPC_LI32(b2p[TMP_REG_1], imm); + if (BPF_CLASS(code) == BPF_ALU) + PPC_MULW(dst_reg, dst_reg, + b2p[TMP_REG_1]); + else + PPC_MULD(dst_reg, dst_reg, + b2p[TMP_REG_1]); + } + goto bpf_alu32_trunc; + case BPF_ALU | BPF_DIV | BPF_X: /* (u32) dst /= (u32) src */ + case BPF_ALU | BPF_MOD | BPF_X: /* (u32) dst %= (u32) src */ + if (BPF_OP(code) == BPF_MOD) { + PPC_DIVWU(b2p[TMP_REG_1], dst_reg, src_reg); + PPC_MULW(b2p[TMP_REG_1], src_reg, + b2p[TMP_REG_1]); + PPC_SUB(dst_reg, dst_reg, b2p[TMP_REG_1]); + } else + PPC_DIVWU(dst_reg, dst_reg, src_reg); + goto bpf_alu32_trunc; + case BPF_ALU64 | BPF_DIV | BPF_X: /* dst /= src */ + case BPF_ALU64 | BPF_MOD | BPF_X: /* dst %= src */ + if (BPF_OP(code) == BPF_MOD) { + PPC_DIVDU(b2p[TMP_REG_1], dst_reg, src_reg); + PPC_MULD(b2p[TMP_REG_1], src_reg, + b2p[TMP_REG_1]); + PPC_SUB(dst_reg, dst_reg, b2p[TMP_REG_1]); + } else + PPC_DIVDU(dst_reg, dst_reg, src_reg); + break; + case BPF_ALU | BPF_MOD | BPF_K: /* (u32) dst %= (u32) imm */ + case BPF_ALU | BPF_DIV | BPF_K: /* (u32) dst /= (u32) imm */ + case BPF_ALU64 | BPF_MOD | BPF_K: /* dst %= imm */ + case BPF_ALU64 | BPF_DIV | BPF_K: /* dst /= imm */ + if (imm == 0) + return -EINVAL; + if (imm == 1) { + if (BPF_OP(code) == BPF_DIV) { + goto bpf_alu32_trunc; + } else { + PPC_LI(dst_reg, 0); + break; + } + } + + PPC_LI32(b2p[TMP_REG_1], imm); + switch (BPF_CLASS(code)) { + case BPF_ALU: + if (BPF_OP(code) == BPF_MOD) { + PPC_DIVWU(b2p[TMP_REG_2], dst_reg, + b2p[TMP_REG_1]); + PPC_MULW(b2p[TMP_REG_1], + b2p[TMP_REG_1], + b2p[TMP_REG_2]); + PPC_SUB(dst_reg, dst_reg, + b2p[TMP_REG_1]); + } else + PPC_DIVWU(dst_reg, dst_reg, + b2p[TMP_REG_1]); + break; + case BPF_ALU64: + if (BPF_OP(code) == BPF_MOD) { + PPC_DIVDU(b2p[TMP_REG_2], dst_reg, + b2p[TMP_REG_1]); + PPC_MULD(b2p[TMP_REG_1], + b2p[TMP_REG_1], + b2p[TMP_REG_2]); + PPC_SUB(dst_reg, dst_reg, + b2p[TMP_REG_1]); + } else + PPC_DIVDU(dst_reg, dst_reg, + b2p[TMP_REG_1]); + break; + } + goto bpf_alu32_trunc; + case BPF_ALU | BPF_NEG: /* (u32) dst = -dst */ + case BPF_ALU64 | BPF_NEG: /* dst = -dst */ + PPC_NEG(dst_reg, dst_reg); + goto bpf_alu32_trunc; + + /* + * Logical operations: AND/OR/XOR/[A]LSH/[A]RSH + */ + case BPF_ALU | BPF_AND | BPF_X: /* (u32) dst = dst & src */ + case BPF_ALU64 | BPF_AND | BPF_X: /* dst = dst & src */ + PPC_AND(dst_reg, dst_reg, src_reg); + goto bpf_alu32_trunc; + case BPF_ALU | BPF_AND | BPF_K: /* (u32) dst = dst & imm */ + case BPF_ALU64 | BPF_AND | BPF_K: /* dst = dst & imm */ + if (!IMM_H(imm)) + PPC_ANDI(dst_reg, dst_reg, IMM_L(imm)); + else { + /* Sign-extended */ + PPC_LI32(b2p[TMP_REG_1], imm); + PPC_AND(dst_reg, dst_reg, b2p[TMP_REG_1]); + } + goto bpf_alu32_trunc; + case BPF_ALU | BPF_OR | BPF_X: /* dst = (u32) dst | (u32) src */ + case BPF_ALU64 | BPF_OR | BPF_X: /* dst = dst | src */ + PPC_OR(dst_reg, dst_reg, src_reg); + goto bpf_alu32_trunc; + case BPF_ALU | BPF_OR | BPF_K:/* dst = (u32) dst | (u32) imm */ + case BPF_ALU64 | BPF_OR | BPF_K:/* dst = dst | imm */ + if (imm < 0 && BPF_CLASS(code) == BPF_ALU64) { + /* Sign-extended */ + PPC_LI32(b2p[TMP_REG_1], imm); + PPC_OR(dst_reg, dst_reg, b2p[TMP_REG_1]); + } else { + if (IMM_L(imm)) + PPC_ORI(dst_reg, dst_reg, IMM_L(imm)); + if (IMM_H(imm)) + PPC_ORIS(dst_reg, dst_reg, IMM_H(imm)); + } + goto bpf_alu32_trunc; + case BPF_ALU | BPF_XOR | BPF_X: /* (u32) dst ^= src */ + case BPF_ALU64 | BPF_XOR | BPF_X: /* dst ^= src */ + PPC_XOR(dst_reg, dst_reg, src_reg); + goto bpf_alu32_trunc; + case BPF_ALU | BPF_XOR | BPF_K: /* (u32) dst ^= (u32) imm */ + case BPF_ALU64 | BPF_XOR | BPF_K: /* dst ^= imm */ + if (imm < 0 && BPF_CLASS(code) == BPF_ALU64) { + /* Sign-extended */ + PPC_LI32(b2p[TMP_REG_1], imm); + PPC_XOR(dst_reg, dst_reg, b2p[TMP_REG_1]); + } else { + if (IMM_L(imm)) + PPC_XORI(dst_reg, dst_reg, IMM_L(imm)); + if (IMM_H(imm)) + PPC_XORIS(dst_reg, dst_reg, IMM_H(imm)); + } + goto bpf_alu32_trunc; + case BPF_ALU | BPF_LSH | BPF_X: /* (u32) dst <<= (u32) src */ + /* slw clears top 32 bits */ + PPC_SLW(dst_reg, dst_reg, src_reg); + break; + case BPF_ALU64 | BPF_LSH | BPF_X: /* dst <<= src; */ + PPC_SLD(dst_reg, dst_reg, src_reg); + break; + case BPF_ALU | BPF_LSH | BPF_K: /* (u32) dst <<== (u32) imm */ + /* with imm 0, we still need to clear top 32 bits */ + PPC_SLWI(dst_reg, dst_reg, imm); + break; + case BPF_ALU64 | BPF_LSH | BPF_K: /* dst <<== imm */ + if (imm != 0) + PPC_SLDI(dst_reg, dst_reg, imm); + break; + case BPF_ALU | BPF_RSH | BPF_X: /* (u32) dst >>= (u32) src */ + PPC_SRW(dst_reg, dst_reg, src_reg); + break; + case BPF_ALU64 | BPF_RSH | BPF_X: /* dst >>= src */ + PPC_SRD(dst_reg, dst_reg, src_reg); + break; + case BPF_ALU | BPF_RSH | BPF_K: /* (u32) dst >>= (u32) imm */ + PPC_SRWI(dst_reg, dst_reg, imm); + break; + case BPF_ALU64 | BPF_RSH | BPF_K: /* dst >>= imm */ + if (imm != 0) + PPC_SRDI(dst_reg, dst_reg, imm); + break; + case BPF_ALU64 | BPF_ARSH | BPF_X: /* (s64) dst >>= src */ + PPC_SRAD(dst_reg, dst_reg, src_reg); + break; + case BPF_ALU64 | BPF_ARSH | BPF_K: /* (s64) dst >>= imm */ + if (imm != 0) + PPC_SRADI(dst_reg, dst_reg, imm); + break; + + /* + * MOV + */ + case BPF_ALU | BPF_MOV | BPF_X: /* (u32) dst = src */ + case BPF_ALU64 | BPF_MOV | BPF_X: /* dst = src */ + PPC_MR(dst_reg, src_reg); + goto bpf_alu32_trunc; + case BPF_ALU | BPF_MOV | BPF_K: /* (u32) dst = imm */ + case BPF_ALU64 | BPF_MOV | BPF_K: /* dst = (s64) imm */ + PPC_LI32(dst_reg, imm); + if (imm < 0) + goto bpf_alu32_trunc; + break; + +bpf_alu32_trunc: + /* Truncate to 32-bits */ + if (BPF_CLASS(code) == BPF_ALU) + PPC_RLWINM(dst_reg, dst_reg, 0, 0, 31); + break; + + /* + * BPF_FROM_BE/LE + */ + case BPF_ALU | BPF_END | BPF_FROM_LE: + case BPF_ALU | BPF_END | BPF_FROM_BE: +#ifdef __BIG_ENDIAN__ + if (BPF_SRC(code) == BPF_FROM_BE) + goto emit_clear; +#else /* !__BIG_ENDIAN__ */ + if (BPF_SRC(code) == BPF_FROM_LE) + goto emit_clear; +#endif + switch (imm) { + case 16: + /* Rotate 8 bits left & mask with 0x0000ff00 */ + PPC_RLWINM(b2p[TMP_REG_1], dst_reg, 8, 16, 23); + /* Rotate 8 bits right & insert LSB to reg */ + PPC_RLWIMI(b2p[TMP_REG_1], dst_reg, 24, 24, 31); + /* Move result back to dst_reg */ + PPC_MR(dst_reg, b2p[TMP_REG_1]); + break; + case 32: + /* + * Rotate word left by 8 bits: + * 2 bytes are already in their final position + * -- byte 2 and 4 (of bytes 1, 2, 3 and 4) + */ + PPC_RLWINM(b2p[TMP_REG_1], dst_reg, 8, 0, 31); + /* Rotate 24 bits and insert byte 1 */ + PPC_RLWIMI(b2p[TMP_REG_1], dst_reg, 24, 0, 7); + /* Rotate 24 bits and insert byte 3 */ + PPC_RLWIMI(b2p[TMP_REG_1], dst_reg, 24, 16, 23); + PPC_MR(dst_reg, b2p[TMP_REG_1]); + break; + case 64: + /* + * Way easier and faster(?) to store the value + * into stack and then use ldbrx + * + * ctx->seen will be reliable in pass2, but + * the instructions generated will remain the + * same across all passes + */ + PPC_BPF_STL(dst_reg, 1, bpf_jit_stack_local(ctx)); + PPC_ADDI(b2p[TMP_REG_1], 1, bpf_jit_stack_local(ctx)); + PPC_LDBRX(dst_reg, 0, b2p[TMP_REG_1]); + break; + } + break; + +emit_clear: + switch (imm) { + case 16: + /* zero-extend 16 bits into 64 bits */ + PPC_RLDICL(dst_reg, dst_reg, 0, 48); + break; + case 32: + /* zero-extend 32 bits into 64 bits */ + PPC_RLDICL(dst_reg, dst_reg, 0, 32); + break; + case 64: + /* nop */ + break; + } + break; + + /* + * BPF_ST NOSPEC (speculation barrier) + */ + case BPF_ST | BPF_NOSPEC: + if (!security_ftr_enabled(SEC_FTR_FAVOUR_SECURITY) || + (!security_ftr_enabled(SEC_FTR_L1D_FLUSH_PR) && + (!security_ftr_enabled(SEC_FTR_L1D_FLUSH_HV) || !cpu_has_feature(CPU_FTR_HVMODE)))) + break; + + switch (stf_barrier) { + case STF_BARRIER_EIEIO: + EMIT(0x7c0006ac | 0x02000000); + break; + case STF_BARRIER_SYNC_ORI: + EMIT(PPC_INST_SYNC); + PPC_LD(b2p[TMP_REG_1], 13, 0); + PPC_ORI(31, 31, 0); + break; + case STF_BARRIER_FALLBACK: + EMIT(PPC_INST_MFLR | ___PPC_RT(b2p[TMP_REG_1])); + PPC_LI64(12, dereference_kernel_function_descriptor(bpf_stf_barrier)); + PPC_MTCTR(12); + EMIT(PPC_INST_BCTR | 0x1); + PPC_MTLR(b2p[TMP_REG_1]); + break; + case STF_BARRIER_NONE: + break; + } + break; + + /* + * BPF_ST(X) + */ + case BPF_STX | BPF_MEM | BPF_B: /* *(u8 *)(dst + off) = src */ + case BPF_ST | BPF_MEM | BPF_B: /* *(u8 *)(dst + off) = imm */ + if (BPF_CLASS(code) == BPF_ST) { + PPC_LI(b2p[TMP_REG_1], imm); + src_reg = b2p[TMP_REG_1]; + } + PPC_STB(src_reg, dst_reg, off); + break; + case BPF_STX | BPF_MEM | BPF_H: /* (u16 *)(dst + off) = src */ + case BPF_ST | BPF_MEM | BPF_H: /* (u16 *)(dst + off) = imm */ + if (BPF_CLASS(code) == BPF_ST) { + PPC_LI(b2p[TMP_REG_1], imm); + src_reg = b2p[TMP_REG_1]; + } + PPC_STH(src_reg, dst_reg, off); + break; + case BPF_STX | BPF_MEM | BPF_W: /* *(u32 *)(dst + off) = src */ + case BPF_ST | BPF_MEM | BPF_W: /* *(u32 *)(dst + off) = imm */ + if (BPF_CLASS(code) == BPF_ST) { + PPC_LI32(b2p[TMP_REG_1], imm); + src_reg = b2p[TMP_REG_1]; + } + PPC_STW(src_reg, dst_reg, off); + break; + case BPF_STX | BPF_MEM | BPF_DW: /* (u64 *)(dst + off) = src */ + case BPF_ST | BPF_MEM | BPF_DW: /* *(u64 *)(dst + off) = imm */ + if (BPF_CLASS(code) == BPF_ST) { + PPC_LI32(b2p[TMP_REG_1], imm); + src_reg = b2p[TMP_REG_1]; + } + PPC_BPF_STL(src_reg, dst_reg, off); + break; + + /* + * BPF_STX XADD (atomic_add) + */ + /* *(u32 *)(dst + off) += src */ + case BPF_STX | BPF_XADD | BPF_W: + /* Get EA into TMP_REG_1 */ + PPC_ADDI(b2p[TMP_REG_1], dst_reg, off); + tmp_idx = ctx->idx * 4; + /* load value from memory into TMP_REG_2 */ + PPC_BPF_LWARX(b2p[TMP_REG_2], 0, b2p[TMP_REG_1], 0); + /* add value from src_reg into this */ + PPC_ADD(b2p[TMP_REG_2], b2p[TMP_REG_2], src_reg); + /* store result back */ + PPC_BPF_STWCX(b2p[TMP_REG_2], 0, b2p[TMP_REG_1]); + /* we're done if this succeeded */ + PPC_BCC_SHORT(COND_NE, tmp_idx); + break; + /* *(u64 *)(dst + off) += src */ + case BPF_STX | BPF_XADD | BPF_DW: + PPC_ADDI(b2p[TMP_REG_1], dst_reg, off); + tmp_idx = ctx->idx * 4; + PPC_BPF_LDARX(b2p[TMP_REG_2], 0, b2p[TMP_REG_1], 0); + PPC_ADD(b2p[TMP_REG_2], b2p[TMP_REG_2], src_reg); + PPC_BPF_STDCX(b2p[TMP_REG_2], 0, b2p[TMP_REG_1]); + PPC_BCC_SHORT(COND_NE, tmp_idx); + break; + + /* + * BPF_LDX + */ + /* dst = *(u8 *)(ul) (src + off) */ + case BPF_LDX | BPF_MEM | BPF_B: + PPC_LBZ(dst_reg, src_reg, off); + break; + /* dst = *(u16 *)(ul) (src + off) */ + case BPF_LDX | BPF_MEM | BPF_H: + PPC_LHZ(dst_reg, src_reg, off); + break; + /* dst = *(u32 *)(ul) (src + off) */ + case BPF_LDX | BPF_MEM | BPF_W: + PPC_LWZ(dst_reg, src_reg, off); + break; + /* dst = *(u64 *)(ul) (src + off) */ + case BPF_LDX | BPF_MEM | BPF_DW: + PPC_BPF_LL(dst_reg, src_reg, off); + break; + + /* + * Doubleword load + * 16 byte instruction that uses two 'struct bpf_insn' + */ + case BPF_LD | BPF_IMM | BPF_DW: /* dst = (u64) imm */ + imm64 = ((u64)(u32) insn[i].imm) | + (((u64)(u32) insn[i+1].imm) << 32); + /* Adjust for two bpf instructions */ + addrs[++i] = ctx->idx * 4; + PPC_LI64(dst_reg, imm64); + break; + + /* + * Return/Exit + */ + case BPF_JMP | BPF_EXIT: + /* + * If this isn't the very last instruction, branch to + * the epilogue. If we _are_ the last instruction, + * we'll just fall through to the epilogue. + */ + if (i != flen - 1) + PPC_JMP(exit_addr); + /* else fall through to the epilogue */ + break; + + /* + * Call kernel helper or bpf function + */ + case BPF_JMP | BPF_CALL: + ctx->seen |= SEEN_FUNC; + + /* bpf function call */ + if (insn[i].src_reg == BPF_PSEUDO_CALL) + if (!extra_pass) + func = NULL; + else if (fp->aux->func && off < fp->aux->func_cnt) + /* use the subprog id from the off + * field to lookup the callee address + */ + func = (u8 *) fp->aux->func[off]->bpf_func; + else + return -EINVAL; + /* kernel helper call */ + else + func = (u8 *) __bpf_call_base + imm; + + bpf_jit_emit_func_call(image, ctx, (u64)func); + + /* move return value from r3 to BPF_REG_0 */ + PPC_MR(b2p[BPF_REG_0], 3); + break; + + /* + * Jumps and branches + */ + case BPF_JMP | BPF_JA: + PPC_JMP(addrs[i + 1 + off]); + break; + + case BPF_JMP | BPF_JGT | BPF_K: + case BPF_JMP | BPF_JGT | BPF_X: + case BPF_JMP | BPF_JSGT | BPF_K: + case BPF_JMP | BPF_JSGT | BPF_X: + true_cond = COND_GT; + goto cond_branch; + case BPF_JMP | BPF_JLT | BPF_K: + case BPF_JMP | BPF_JLT | BPF_X: + case BPF_JMP | BPF_JSLT | BPF_K: + case BPF_JMP | BPF_JSLT | BPF_X: + true_cond = COND_LT; + goto cond_branch; + case BPF_JMP | BPF_JGE | BPF_K: + case BPF_JMP | BPF_JGE | BPF_X: + case BPF_JMP | BPF_JSGE | BPF_K: + case BPF_JMP | BPF_JSGE | BPF_X: + true_cond = COND_GE; + goto cond_branch; + case BPF_JMP | BPF_JLE | BPF_K: + case BPF_JMP | BPF_JLE | BPF_X: + case BPF_JMP | BPF_JSLE | BPF_K: + case BPF_JMP | BPF_JSLE | BPF_X: + true_cond = COND_LE; + 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_JNE | BPF_K: + case BPF_JMP | BPF_JNE | BPF_X: + true_cond = COND_NE; + 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: + switch (code) { + case BPF_JMP | BPF_JGT | BPF_X: + case BPF_JMP | BPF_JLT | BPF_X: + case BPF_JMP | BPF_JGE | BPF_X: + case BPF_JMP | BPF_JLE | BPF_X: + case BPF_JMP | BPF_JEQ | BPF_X: + case BPF_JMP | BPF_JNE | BPF_X: + /* unsigned comparison */ + PPC_CMPLD(dst_reg, src_reg); + break; + case BPF_JMP | BPF_JSGT | BPF_X: + case BPF_JMP | BPF_JSLT | BPF_X: + case BPF_JMP | BPF_JSGE | BPF_X: + case BPF_JMP | BPF_JSLE | BPF_X: + /* signed comparison */ + PPC_CMPD(dst_reg, src_reg); + break; + case BPF_JMP | BPF_JSET | BPF_X: + PPC_AND_DOT(b2p[TMP_REG_1], dst_reg, src_reg); + break; + case BPF_JMP | BPF_JNE | BPF_K: + case BPF_JMP | BPF_JEQ | BPF_K: + case BPF_JMP | BPF_JGT | BPF_K: + case BPF_JMP | BPF_JLT | BPF_K: + case BPF_JMP | BPF_JGE | BPF_K: + case BPF_JMP | BPF_JLE | BPF_K: + /* + * Need sign-extended load, so only positive + * values can be used as imm in cmpldi + */ + if (imm >= 0 && imm < 32768) + PPC_CMPLDI(dst_reg, imm); + else { + /* sign-extending load */ + PPC_LI32(b2p[TMP_REG_1], imm); + /* ... but unsigned comparison */ + PPC_CMPLD(dst_reg, b2p[TMP_REG_1]); + } + break; + case BPF_JMP | BPF_JSGT | BPF_K: + case BPF_JMP | BPF_JSLT | BPF_K: + case BPF_JMP | BPF_JSGE | BPF_K: + case BPF_JMP | BPF_JSLE | BPF_K: + /* + * signed comparison, so any 16-bit value + * can be used in cmpdi + */ + if (imm >= -32768 && imm < 32768) + PPC_CMPDI(dst_reg, imm); + else { + PPC_LI32(b2p[TMP_REG_1], imm); + PPC_CMPD(dst_reg, b2p[TMP_REG_1]); + } + break; + case BPF_JMP | BPF_JSET | BPF_K: + /* andi does not sign-extend the immediate */ + if (imm >= 0 && imm < 32768) + /* PPC_ANDI is _only/always_ dot-form */ + PPC_ANDI(b2p[TMP_REG_1], dst_reg, imm); + else { + PPC_LI32(b2p[TMP_REG_1], imm); + PPC_AND_DOT(b2p[TMP_REG_1], dst_reg, + b2p[TMP_REG_1]); + } + break; + } + PPC_BCC(true_cond, addrs[i + 1 + off]); + break; + + /* + * Tail call + */ + case BPF_JMP | BPF_TAIL_CALL: + ctx->seen |= SEEN_TAILCALL; + ret = bpf_jit_emit_tail_call(image, ctx, addrs[i + 1]); + if (ret < 0) + return ret; + break; + + default: + /* + * The filter contains something cruel & unusual. + * We don't handle it, but also there shouldn't be + * anything missing from our list. + */ + pr_err_ratelimited("eBPF filter opcode %04x (@%d) unsupported\n", + code, i); + return -ENOTSUPP; + } + } + + /* Set end-of-body-code address for exit. */ + addrs[i] = ctx->idx * 4; + + return 0; +} + +struct powerpc64_jit_data { + struct bpf_binary_header *header; + u32 *addrs; + u8 *image; + u32 proglen; + struct codegen_context ctx; +}; + +struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp) +{ + u32 proglen; + u32 alloclen; + u8 *image = NULL; + u32 *code_base; + u32 *addrs; + struct powerpc64_jit_data *jit_data; + struct codegen_context cgctx; + int pass; + int flen; + struct bpf_binary_header *bpf_hdr; + struct bpf_prog *org_fp = fp; + struct bpf_prog *tmp_fp; + bool bpf_blinded = false; + bool extra_pass = false; + + if (!fp->jit_requested) + return org_fp; + + tmp_fp = bpf_jit_blind_constants(org_fp); + if (IS_ERR(tmp_fp)) + return org_fp; + + if (tmp_fp != org_fp) { + bpf_blinded = true; + fp = tmp_fp; + } + + jit_data = fp->aux->jit_data; + if (!jit_data) { + jit_data = kzalloc(sizeof(*jit_data), GFP_KERNEL); + if (!jit_data) { + fp = org_fp; + goto out; + } + fp->aux->jit_data = jit_data; + } + + flen = fp->len; + addrs = jit_data->addrs; + if (addrs) { + cgctx = jit_data->ctx; + image = jit_data->image; + bpf_hdr = jit_data->header; + proglen = jit_data->proglen; + alloclen = proglen + FUNCTION_DESCR_SIZE; + extra_pass = true; + goto skip_init_ctx; + } + + addrs = kcalloc(flen + 1, sizeof(*addrs), GFP_KERNEL); + if (addrs == NULL) { + fp = org_fp; + goto out_addrs; + } + + memset(&cgctx, 0, sizeof(struct codegen_context)); + + /* Make sure that the stack is quadword aligned. */ + cgctx.stack_size = round_up(fp->aux->stack_depth, 16); + + /* Scouting faux-generate pass 0 */ + if (bpf_jit_build_body(fp, 0, &cgctx, addrs, false)) { + /* We hit something illegal or unsupported. */ + fp = org_fp; + goto out_addrs; + } + + /* + * If we have seen a tail call, we need a second pass. + * This is because bpf_jit_emit_common_epilogue() is called + * from bpf_jit_emit_tail_call() with a not yet stable ctx->seen. + */ + if (cgctx.seen & SEEN_TAILCALL) { + cgctx.idx = 0; + if (bpf_jit_build_body(fp, 0, &cgctx, addrs, false)) { + fp = org_fp; + goto out_addrs; + } + } + + /* + * Pretend to build prologue, given the features we've seen. This will + * update ctgtx.idx as it pretends to output instructions, then we can + * calculate total size from idx. + */ + bpf_jit_build_prologue(0, &cgctx); + bpf_jit_build_epilogue(0, &cgctx); + + proglen = cgctx.idx * 4; + alloclen = proglen + FUNCTION_DESCR_SIZE; + + bpf_hdr = bpf_jit_binary_alloc(alloclen, &image, 4, + bpf_jit_fill_ill_insns); + if (!bpf_hdr) { + fp = org_fp; + goto out_addrs; + } + +skip_init_ctx: + code_base = (u32 *)(image + FUNCTION_DESCR_SIZE); + + /* Code generation passes 1-2 */ + for (pass = 1; pass < 3; pass++) { + /* Now build the prologue, body code & epilogue for real. */ + cgctx.idx = 0; + bpf_jit_build_prologue(code_base, &cgctx); + bpf_jit_build_body(fp, code_base, &cgctx, addrs, extra_pass); + bpf_jit_build_epilogue(code_base, &cgctx); + + if (bpf_jit_enable > 1) + pr_info("Pass %d: shrink = %d, seen = 0x%x\n", pass, + proglen - (cgctx.idx * 4), cgctx.seen); + } + + if (bpf_jit_enable > 1) + /* + * Note that we output the base address of the code_base + * rather than image, since opcodes are in code_base. + */ + bpf_jit_dump(flen, proglen, pass, code_base); + +#ifdef PPC64_ELF_ABI_v1 + /* Function descriptor nastiness: Address + TOC */ + ((u64 *)image)[0] = (u64)code_base; + ((u64 *)image)[1] = local_paca->kernel_toc; +#endif + + fp->bpf_func = (void *)image; + fp->jited = 1; + fp->jited_len = alloclen; + + bpf_flush_icache(bpf_hdr, (u8 *)bpf_hdr + (bpf_hdr->pages * PAGE_SIZE)); + if (!fp->is_func || extra_pass) { +out_addrs: + kfree(addrs); + kfree(jit_data); + fp->aux->jit_data = NULL; + } else { + jit_data->addrs = addrs; + jit_data->ctx = cgctx; + jit_data->proglen = proglen; + jit_data->image = image; + jit_data->header = bpf_hdr; + } + +out: + if (bpf_blinded) + bpf_jit_prog_release_other(fp, fp == org_fp ? tmp_fp : org_fp); + + return fp; +} + +/* Overriding bpf_jit_free() as we don't set images read-only. */ +void bpf_jit_free(struct bpf_prog *fp) +{ + unsigned long addr = (unsigned long)fp->bpf_func & PAGE_MASK; + struct bpf_binary_header *bpf_hdr = (void *)addr; + + if (fp->jited) + bpf_jit_binary_free(bpf_hdr); + + bpf_prog_unlock_free(fp); +} |