diff options
Diffstat (limited to 'arch/arm64/net/bpf_jit_comp.c')
| -rw-r--r-- | arch/arm64/net/bpf_jit_comp.c | 679 |
1 files changed, 679 insertions, 0 deletions
diff --git a/arch/arm64/net/bpf_jit_comp.c b/arch/arm64/net/bpf_jit_comp.c new file mode 100644 index 000000000000..7ae33545535b --- /dev/null +++ b/arch/arm64/net/bpf_jit_comp.c @@ -0,0 +1,679 @@ +/* + * BPF JIT compiler for ARM64 + * + * Copyright (C) 2014 Zi Shen Lim <zlim.lnx@gmail.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ + +#define pr_fmt(fmt) "bpf_jit: " fmt + +#include <linux/filter.h> +#include <linux/moduleloader.h> +#include <linux/printk.h> +#include <linux/skbuff.h> +#include <linux/slab.h> +#include <asm/byteorder.h> +#include <asm/cacheflush.h> + +#include "bpf_jit.h" + +int bpf_jit_enable __read_mostly; + +#define TMP_REG_1 (MAX_BPF_REG + 0) +#define TMP_REG_2 (MAX_BPF_REG + 1) + +/* Map BPF registers to A64 registers */ +static const int bpf2a64[] = { + /* return value from in-kernel function, and exit value from eBPF */ + [BPF_REG_0] = A64_R(7), + /* arguments from eBPF program to in-kernel function */ + [BPF_REG_1] = A64_R(0), + [BPF_REG_2] = A64_R(1), + [BPF_REG_3] = A64_R(2), + [BPF_REG_4] = A64_R(3), + [BPF_REG_5] = A64_R(4), + /* callee saved registers that in-kernel function will preserve */ + [BPF_REG_6] = A64_R(19), + [BPF_REG_7] = A64_R(20), + [BPF_REG_8] = A64_R(21), + [BPF_REG_9] = A64_R(22), + /* read-only frame pointer to access stack */ + [BPF_REG_FP] = A64_FP, + /* temporary register for internal BPF JIT */ + [TMP_REG_1] = A64_R(23), + [TMP_REG_2] = A64_R(24), +}; + +struct jit_ctx { + const struct bpf_prog *prog; + int idx; + int tmp_used; + int body_offset; + int *offset; + u32 *image; +}; + +static inline void emit(const u32 insn, struct jit_ctx *ctx) +{ + if (ctx->image != NULL) + ctx->image[ctx->idx] = cpu_to_le32(insn); + + ctx->idx++; +} + +static inline void emit_a64_mov_i64(const int reg, const u64 val, + struct jit_ctx *ctx) +{ + u64 tmp = val; + int shift = 0; + + emit(A64_MOVZ(1, reg, tmp & 0xffff, shift), ctx); + tmp >>= 16; + shift += 16; + while (tmp) { + if (tmp & 0xffff) + emit(A64_MOVK(1, reg, tmp & 0xffff, shift), ctx); + tmp >>= 16; + shift += 16; + } +} + +static inline void emit_a64_mov_i(const int is64, const int reg, + const s32 val, struct jit_ctx *ctx) +{ + u16 hi = val >> 16; + u16 lo = val & 0xffff; + + if (hi & 0x8000) { + if (hi == 0xffff) { + emit(A64_MOVN(is64, reg, (u16)~lo, 0), ctx); + } else { + emit(A64_MOVN(is64, reg, (u16)~hi, 16), ctx); + emit(A64_MOVK(is64, reg, lo, 0), ctx); + } + } else { + emit(A64_MOVZ(is64, reg, lo, 0), ctx); + if (hi) + emit(A64_MOVK(is64, reg, hi, 16), ctx); + } +} + +static inline int bpf2a64_offset(int bpf_to, int bpf_from, + const struct jit_ctx *ctx) +{ + int to = ctx->offset[bpf_to + 1]; + /* -1 to account for the Branch instruction */ + int from = ctx->offset[bpf_from + 1] - 1; + + return to - from; +} + +static inline int epilogue_offset(const struct jit_ctx *ctx) +{ + int to = ctx->offset[ctx->prog->len - 1]; + int from = ctx->idx - ctx->body_offset; + + return to - from; +} + +/* Stack must be multiples of 16B */ +#define STACK_ALIGN(sz) (((sz) + 15) & ~15) + +static void build_prologue(struct jit_ctx *ctx) +{ + const u8 r6 = bpf2a64[BPF_REG_6]; + const u8 r7 = bpf2a64[BPF_REG_7]; + const u8 r8 = bpf2a64[BPF_REG_8]; + const u8 r9 = bpf2a64[BPF_REG_9]; + const u8 fp = bpf2a64[BPF_REG_FP]; + const u8 ra = bpf2a64[BPF_REG_A]; + const u8 rx = bpf2a64[BPF_REG_X]; + const u8 tmp1 = bpf2a64[TMP_REG_1]; + const u8 tmp2 = bpf2a64[TMP_REG_2]; + int stack_size = MAX_BPF_STACK; + + stack_size += 4; /* extra for skb_copy_bits buffer */ + stack_size = STACK_ALIGN(stack_size); + + /* Save callee-saved register */ + emit(A64_PUSH(r6, r7, A64_SP), ctx); + emit(A64_PUSH(r8, r9, A64_SP), ctx); + if (ctx->tmp_used) + emit(A64_PUSH(tmp1, tmp2, A64_SP), ctx); + + /* Set up BPF stack */ + emit(A64_SUB_I(1, A64_SP, A64_SP, stack_size), ctx); + + /* Set up frame pointer */ + emit(A64_MOV(1, fp, A64_SP), ctx); + + /* Clear registers A and X */ + emit_a64_mov_i64(ra, 0, ctx); + emit_a64_mov_i64(rx, 0, ctx); +} + +static void build_epilogue(struct jit_ctx *ctx) +{ + const u8 r0 = bpf2a64[BPF_REG_0]; + const u8 r6 = bpf2a64[BPF_REG_6]; + const u8 r7 = bpf2a64[BPF_REG_7]; + const u8 r8 = bpf2a64[BPF_REG_8]; + const u8 r9 = bpf2a64[BPF_REG_9]; + const u8 fp = bpf2a64[BPF_REG_FP]; + const u8 tmp1 = bpf2a64[TMP_REG_1]; + const u8 tmp2 = bpf2a64[TMP_REG_2]; + int stack_size = MAX_BPF_STACK; + + stack_size += 4; /* extra for skb_copy_bits buffer */ + stack_size = STACK_ALIGN(stack_size); + + /* We're done with BPF stack */ + emit(A64_ADD_I(1, A64_SP, A64_SP, stack_size), ctx); + + /* Restore callee-saved register */ + if (ctx->tmp_used) + emit(A64_POP(tmp1, tmp2, A64_SP), ctx); + emit(A64_POP(r8, r9, A64_SP), ctx); + emit(A64_POP(r6, r7, A64_SP), ctx); + + /* Restore frame pointer */ + emit(A64_MOV(1, fp, A64_SP), ctx); + + /* Set return value */ + emit(A64_MOV(1, A64_R(0), r0), ctx); + + emit(A64_RET(A64_LR), ctx); +} + +static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx) +{ + const u8 code = insn->code; + const u8 dst = bpf2a64[insn->dst_reg]; + const u8 src = bpf2a64[insn->src_reg]; + const u8 tmp = bpf2a64[TMP_REG_1]; + const u8 tmp2 = bpf2a64[TMP_REG_2]; + const s16 off = insn->off; + const s32 imm = insn->imm; + const int i = insn - ctx->prog->insnsi; + const bool is64 = BPF_CLASS(code) == BPF_ALU64; + u8 jmp_cond; + s32 jmp_offset; + + switch (code) { + /* dst = src */ + case BPF_ALU | BPF_MOV | BPF_X: + case BPF_ALU64 | BPF_MOV | BPF_X: + emit(A64_MOV(is64, dst, src), ctx); + break; + /* dst = dst OP src */ + case BPF_ALU | BPF_ADD | BPF_X: + case BPF_ALU64 | BPF_ADD | BPF_X: + emit(A64_ADD(is64, dst, dst, src), ctx); + break; + case BPF_ALU | BPF_SUB | BPF_X: + case BPF_ALU64 | BPF_SUB | BPF_X: + emit(A64_SUB(is64, dst, dst, src), ctx); + break; + case BPF_ALU | BPF_AND | BPF_X: + case BPF_ALU64 | BPF_AND | BPF_X: + emit(A64_AND(is64, dst, dst, src), ctx); + break; + case BPF_ALU | BPF_OR | BPF_X: + case BPF_ALU64 | BPF_OR | BPF_X: + emit(A64_ORR(is64, dst, dst, src), ctx); + break; + case BPF_ALU | BPF_XOR | BPF_X: + case BPF_ALU64 | BPF_XOR | BPF_X: + emit(A64_EOR(is64, dst, dst, src), ctx); + break; + case BPF_ALU | BPF_MUL | BPF_X: + case BPF_ALU64 | BPF_MUL | BPF_X: + emit(A64_MUL(is64, dst, dst, src), ctx); + break; + case BPF_ALU | BPF_DIV | BPF_X: + case BPF_ALU64 | BPF_DIV | BPF_X: + emit(A64_UDIV(is64, dst, dst, src), ctx); + break; + case BPF_ALU | BPF_MOD | BPF_X: + case BPF_ALU64 | BPF_MOD | BPF_X: + ctx->tmp_used = 1; + emit(A64_UDIV(is64, tmp, dst, src), ctx); + emit(A64_MUL(is64, tmp, tmp, src), ctx); + emit(A64_SUB(is64, dst, dst, tmp), ctx); + break; + /* dst = -dst */ + case BPF_ALU | BPF_NEG: + case BPF_ALU64 | BPF_NEG: + emit(A64_NEG(is64, dst, dst), ctx); + break; + /* dst = BSWAP##imm(dst) */ + case BPF_ALU | BPF_END | BPF_FROM_LE: + case BPF_ALU | BPF_END | BPF_FROM_BE: +#ifdef CONFIG_CPU_BIG_ENDIAN + if (BPF_SRC(code) == BPF_FROM_BE) + break; +#else /* !CONFIG_CPU_BIG_ENDIAN */ + if (BPF_SRC(code) == BPF_FROM_LE) + break; +#endif + switch (imm) { + case 16: + emit(A64_REV16(is64, dst, dst), ctx); + break; + case 32: + emit(A64_REV32(is64, dst, dst), ctx); + break; + case 64: + emit(A64_REV64(dst, dst), ctx); + break; + } + break; + /* dst = imm */ + case BPF_ALU | BPF_MOV | BPF_K: + case BPF_ALU64 | BPF_MOV | BPF_K: + emit_a64_mov_i(is64, dst, imm, ctx); + break; + /* dst = dst OP imm */ + case BPF_ALU | BPF_ADD | BPF_K: + case BPF_ALU64 | BPF_ADD | BPF_K: + ctx->tmp_used = 1; + emit_a64_mov_i(is64, tmp, imm, ctx); + emit(A64_ADD(is64, dst, dst, tmp), ctx); + break; + case BPF_ALU | BPF_SUB | BPF_K: + case BPF_ALU64 | BPF_SUB | BPF_K: + ctx->tmp_used = 1; + emit_a64_mov_i(is64, tmp, imm, ctx); + emit(A64_SUB(is64, dst, dst, tmp), ctx); + break; + case BPF_ALU | BPF_AND | BPF_K: + case BPF_ALU64 | BPF_AND | BPF_K: + ctx->tmp_used = 1; + emit_a64_mov_i(is64, tmp, imm, ctx); + emit(A64_AND(is64, dst, dst, tmp), ctx); + break; + case BPF_ALU | BPF_OR | BPF_K: + case BPF_ALU64 | BPF_OR | BPF_K: + ctx->tmp_used = 1; + emit_a64_mov_i(is64, tmp, imm, ctx); + emit(A64_ORR(is64, dst, dst, tmp), ctx); + break; + case BPF_ALU | BPF_XOR | BPF_K: + case BPF_ALU64 | BPF_XOR | BPF_K: + ctx->tmp_used = 1; + emit_a64_mov_i(is64, tmp, imm, ctx); + emit(A64_EOR(is64, dst, dst, tmp), ctx); + break; + case BPF_ALU | BPF_MUL | BPF_K: + case BPF_ALU64 | BPF_MUL | BPF_K: + ctx->tmp_used = 1; + emit_a64_mov_i(is64, tmp, imm, ctx); + emit(A64_MUL(is64, dst, dst, tmp), ctx); + break; + case BPF_ALU | BPF_DIV | BPF_K: + case BPF_ALU64 | BPF_DIV | BPF_K: + ctx->tmp_used = 1; + emit_a64_mov_i(is64, tmp, imm, ctx); + emit(A64_UDIV(is64, dst, dst, tmp), ctx); + break; + case BPF_ALU | BPF_MOD | BPF_K: + case BPF_ALU64 | BPF_MOD | BPF_K: + ctx->tmp_used = 1; + emit_a64_mov_i(is64, tmp2, imm, ctx); + emit(A64_UDIV(is64, tmp, dst, tmp2), ctx); + emit(A64_MUL(is64, tmp, tmp, tmp2), ctx); + emit(A64_SUB(is64, dst, dst, tmp), ctx); + break; + case BPF_ALU | BPF_LSH | BPF_K: + case BPF_ALU64 | BPF_LSH | BPF_K: + emit(A64_LSL(is64, dst, dst, imm), ctx); + break; + case BPF_ALU | BPF_RSH | BPF_K: + case BPF_ALU64 | BPF_RSH | BPF_K: + emit(A64_LSR(is64, dst, dst, imm), ctx); + break; + case BPF_ALU | BPF_ARSH | BPF_K: + case BPF_ALU64 | BPF_ARSH | BPF_K: + emit(A64_ASR(is64, dst, dst, imm), ctx); + break; + +#define check_imm(bits, imm) do { \ + if ((((imm) > 0) && ((imm) >> (bits))) || \ + (((imm) < 0) && (~(imm) >> (bits)))) { \ + pr_info("[%2d] imm=%d(0x%x) out of range\n", \ + i, imm, imm); \ + return -EINVAL; \ + } \ +} while (0) +#define check_imm19(imm) check_imm(19, imm) +#define check_imm26(imm) check_imm(26, imm) + + /* JUMP off */ + case BPF_JMP | BPF_JA: + jmp_offset = bpf2a64_offset(i + off, i, ctx); + check_imm26(jmp_offset); + emit(A64_B(jmp_offset), ctx); + break; + /* IF (dst COND src) JUMP off */ + case BPF_JMP | BPF_JEQ | BPF_X: + case BPF_JMP | BPF_JGT | BPF_X: + case BPF_JMP | BPF_JGE | BPF_X: + case BPF_JMP | BPF_JNE | BPF_X: + case BPF_JMP | BPF_JSGT | BPF_X: + case BPF_JMP | BPF_JSGE | BPF_X: + emit(A64_CMP(1, dst, src), ctx); +emit_cond_jmp: + jmp_offset = bpf2a64_offset(i + off, i, ctx); + check_imm19(jmp_offset); + switch (BPF_OP(code)) { + case BPF_JEQ: + jmp_cond = A64_COND_EQ; + break; + case BPF_JGT: + jmp_cond = A64_COND_HI; + break; + case BPF_JGE: + jmp_cond = A64_COND_CS; + break; + case BPF_JNE: + jmp_cond = A64_COND_NE; + break; + case BPF_JSGT: + jmp_cond = A64_COND_GT; + break; + case BPF_JSGE: + jmp_cond = A64_COND_GE; + break; + default: + return -EFAULT; + } + emit(A64_B_(jmp_cond, jmp_offset), ctx); + break; + case BPF_JMP | BPF_JSET | BPF_X: + emit(A64_TST(1, dst, src), ctx); + goto emit_cond_jmp; + /* IF (dst COND imm) JUMP off */ + case BPF_JMP | BPF_JEQ | BPF_K: + case BPF_JMP | BPF_JGT | BPF_K: + case BPF_JMP | BPF_JGE | BPF_K: + case BPF_JMP | BPF_JNE | BPF_K: + case BPF_JMP | BPF_JSGT | BPF_K: + case BPF_JMP | BPF_JSGE | BPF_K: + ctx->tmp_used = 1; + emit_a64_mov_i(1, tmp, imm, ctx); + emit(A64_CMP(1, dst, tmp), ctx); + goto emit_cond_jmp; + case BPF_JMP | BPF_JSET | BPF_K: + ctx->tmp_used = 1; + emit_a64_mov_i(1, tmp, imm, ctx); + emit(A64_TST(1, dst, tmp), ctx); + goto emit_cond_jmp; + /* function call */ + case BPF_JMP | BPF_CALL: + { + const u8 r0 = bpf2a64[BPF_REG_0]; + const u64 func = (u64)__bpf_call_base + imm; + + ctx->tmp_used = 1; + emit_a64_mov_i64(tmp, func, ctx); + emit(A64_PUSH(A64_FP, A64_LR, A64_SP), ctx); + emit(A64_MOV(1, A64_FP, A64_SP), ctx); + emit(A64_BLR(tmp), ctx); + emit(A64_MOV(1, r0, A64_R(0)), ctx); + emit(A64_POP(A64_FP, A64_LR, A64_SP), ctx); + break; + } + /* function return */ + case BPF_JMP | BPF_EXIT: + if (i == ctx->prog->len - 1) + break; + jmp_offset = epilogue_offset(ctx); + check_imm26(jmp_offset); + emit(A64_B(jmp_offset), ctx); + break; + + /* LDX: dst = *(size *)(src + off) */ + case BPF_LDX | BPF_MEM | BPF_W: + case BPF_LDX | BPF_MEM | BPF_H: + case BPF_LDX | BPF_MEM | BPF_B: + case BPF_LDX | BPF_MEM | BPF_DW: + ctx->tmp_used = 1; + emit_a64_mov_i(1, tmp, off, ctx); + switch (BPF_SIZE(code)) { + case BPF_W: + emit(A64_LDR32(dst, src, tmp), ctx); + break; + case BPF_H: + emit(A64_LDRH(dst, src, tmp), ctx); + break; + case BPF_B: + emit(A64_LDRB(dst, src, tmp), ctx); + break; + case BPF_DW: + emit(A64_LDR64(dst, src, tmp), ctx); + break; + } + break; + + /* ST: *(size *)(dst + off) = imm */ + case BPF_ST | BPF_MEM | BPF_W: + case BPF_ST | BPF_MEM | BPF_H: + case BPF_ST | BPF_MEM | BPF_B: + case BPF_ST | BPF_MEM | BPF_DW: + goto notyet; + + /* STX: *(size *)(dst + off) = src */ + case BPF_STX | BPF_MEM | BPF_W: + case BPF_STX | BPF_MEM | BPF_H: + case BPF_STX | BPF_MEM | BPF_B: + case BPF_STX | BPF_MEM | BPF_DW: + ctx->tmp_used = 1; + emit_a64_mov_i(1, tmp, off, ctx); + switch (BPF_SIZE(code)) { + case BPF_W: + emit(A64_STR32(src, dst, tmp), ctx); + break; + case BPF_H: + emit(A64_STRH(src, dst, tmp), ctx); + break; + case BPF_B: + emit(A64_STRB(src, dst, tmp), ctx); + break; + case BPF_DW: + emit(A64_STR64(src, dst, tmp), ctx); + break; + } + break; + /* STX XADD: lock *(u32 *)(dst + off) += src */ + case BPF_STX | BPF_XADD | BPF_W: + /* STX XADD: lock *(u64 *)(dst + off) += src */ + case BPF_STX | BPF_XADD | BPF_DW: + goto notyet; + + /* R0 = ntohx(*(size *)(((struct sk_buff *)R6)->data + imm)) */ + case BPF_LD | BPF_ABS | BPF_W: + case BPF_LD | BPF_ABS | BPF_H: + case BPF_LD | BPF_ABS | BPF_B: + /* R0 = ntohx(*(size *)(((struct sk_buff *)R6)->data + src + imm)) */ + case BPF_LD | BPF_IND | BPF_W: + case BPF_LD | BPF_IND | BPF_H: + case BPF_LD | BPF_IND | BPF_B: + { + const u8 r0 = bpf2a64[BPF_REG_0]; /* r0 = return value */ + const u8 r6 = bpf2a64[BPF_REG_6]; /* r6 = pointer to sk_buff */ + const u8 fp = bpf2a64[BPF_REG_FP]; + const u8 r1 = bpf2a64[BPF_REG_1]; /* r1: struct sk_buff *skb */ + const u8 r2 = bpf2a64[BPF_REG_2]; /* r2: int k */ + const u8 r3 = bpf2a64[BPF_REG_3]; /* r3: unsigned int size */ + const u8 r4 = bpf2a64[BPF_REG_4]; /* r4: void *buffer */ + const u8 r5 = bpf2a64[BPF_REG_5]; /* r5: void *(*func)(...) */ + int size; + + emit(A64_MOV(1, r1, r6), ctx); + emit_a64_mov_i(0, r2, imm, ctx); + if (BPF_MODE(code) == BPF_IND) + emit(A64_ADD(0, r2, r2, src), ctx); + switch (BPF_SIZE(code)) { + case BPF_W: + size = 4; + break; + case BPF_H: + size = 2; + break; + case BPF_B: + size = 1; + break; + default: + return -EINVAL; + } + emit_a64_mov_i64(r3, size, ctx); + emit(A64_ADD_I(1, r4, fp, MAX_BPF_STACK), ctx); + emit_a64_mov_i64(r5, (unsigned long)bpf_load_pointer, ctx); + emit(A64_PUSH(A64_FP, A64_LR, A64_SP), ctx); + emit(A64_MOV(1, A64_FP, A64_SP), ctx); + emit(A64_BLR(r5), ctx); + emit(A64_MOV(1, r0, A64_R(0)), ctx); + emit(A64_POP(A64_FP, A64_LR, A64_SP), ctx); + + jmp_offset = epilogue_offset(ctx); + check_imm19(jmp_offset); + emit(A64_CBZ(1, r0, jmp_offset), ctx); + emit(A64_MOV(1, r5, r0), ctx); + switch (BPF_SIZE(code)) { + case BPF_W: + emit(A64_LDR32(r0, r5, A64_ZR), ctx); +#ifndef CONFIG_CPU_BIG_ENDIAN + emit(A64_REV32(0, r0, r0), ctx); +#endif + break; + case BPF_H: + emit(A64_LDRH(r0, r5, A64_ZR), ctx); +#ifndef CONFIG_CPU_BIG_ENDIAN + emit(A64_REV16(0, r0, r0), ctx); +#endif + break; + case BPF_B: + emit(A64_LDRB(r0, r5, A64_ZR), ctx); + break; + } + break; + } +notyet: + pr_info_once("*** NOT YET: opcode %02x ***\n", code); + return -EFAULT; + + default: + pr_err_once("unknown opcode %02x\n", code); + return -EINVAL; + } + + return 0; +} + +static int build_body(struct jit_ctx *ctx) +{ + const struct bpf_prog *prog = ctx->prog; + int i; + + for (i = 0; i < prog->len; i++) { + const struct bpf_insn *insn = &prog->insnsi[i]; + int ret; + + if (ctx->image == NULL) + ctx->offset[i] = ctx->idx; + + ret = build_insn(insn, ctx); + if (ret) + return ret; + } + + return 0; +} + +static inline void bpf_flush_icache(void *start, void *end) +{ + flush_icache_range((unsigned long)start, (unsigned long)end); +} + +void bpf_jit_compile(struct bpf_prog *prog) +{ + /* Nothing to do here. We support Internal BPF. */ +} + +void bpf_int_jit_compile(struct bpf_prog *prog) +{ + struct jit_ctx ctx; + int image_size; + + if (!bpf_jit_enable) + return; + + if (!prog || !prog->len) + return; + + memset(&ctx, 0, sizeof(ctx)); + ctx.prog = prog; + + ctx.offset = kcalloc(prog->len, sizeof(int), GFP_KERNEL); + if (ctx.offset == NULL) + return; + + /* 1. Initial fake pass to compute ctx->idx. */ + + /* Fake pass to fill in ctx->offset. */ + if (build_body(&ctx)) + goto out; + + build_prologue(&ctx); + + build_epilogue(&ctx); + + /* Now we know the actual image size. */ + image_size = sizeof(u32) * ctx.idx; + ctx.image = module_alloc(image_size); + if (unlikely(ctx.image == NULL)) + goto out; + + /* 2. Now, the actual pass. */ + + ctx.idx = 0; + build_prologue(&ctx); + + ctx.body_offset = ctx.idx; + if (build_body(&ctx)) { + module_free(NULL, ctx.image); + goto out; + } + + build_epilogue(&ctx); + + /* And we're done. */ + if (bpf_jit_enable > 1) + bpf_jit_dump(prog->len, image_size, 2, ctx.image); + + bpf_flush_icache(ctx.image, ctx.image + ctx.idx); + prog->bpf_func = (void *)ctx.image; + prog->jited = 1; + +out: + kfree(ctx.offset); +} + +void bpf_jit_free(struct bpf_prog *prog) +{ + if (prog->jited) + module_free(NULL, prog->bpf_func); + + kfree(prog); +} |