Author | Tokens | Token Proportion | Commits | Commit Proportion |
---|---|---|---|---|
Naveen N. Rao | 4272 | 76.07% | 8 | 29.63% |
Jiong Wang | 553 | 9.85% | 2 | 7.41% |
Sandipan Das | 492 | 8.76% | 5 | 18.52% |
Daniel Borkmann | 282 | 5.02% | 6 | 22.22% |
Martin KaFai Lau | 6 | 0.11% | 1 | 3.70% |
Alexei Starovoitov | 4 | 0.07% | 2 | 7.41% |
Christophe Leroy | 3 | 0.05% | 1 | 3.70% |
Thomas Gleixner | 2 | 0.04% | 1 | 3.70% |
Kees Cook | 2 | 0.04% | 1 | 3.70% |
Total | 5616 | 27 |
// SPDX-License-Identifier: GPL-2.0-only /* * 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 */ #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 "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 ] 6*8 * [ tail_call_cnt ] 8 * [ local_tmp_var ] 8 * [ 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 + 16); } static int bpf_jit_stack_tailcallcnt(struct codegen_context *ctx) { return bpf_jit_stack_local(ctx) + 8; } 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_hlp(u32 *image, struct codegen_context *ctx, u64 func) { #ifdef PPC64_ELF_ABI_v1 /* func points to the function descriptor */ PPC_LI64(b2p[TMP_REG_2], func); /* Load actual entry point from function descriptor */ PPC_BPF_LL(b2p[TMP_REG_1], b2p[TMP_REG_2], 0); /* ... and move it to LR */ PPC_MTLR(b2p[TMP_REG_1]); /* * 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, b2p[TMP_REG_2], 8); #else /* We can clobber r12 */ PPC_FUNC_ADDR(12, func); PPC_MTLR(12); #endif PPC_BLRL(); } static void bpf_jit_emit_func_call_rel(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 void 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: */ } /* 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) { 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; bool func_addr_fixed; u64 func_addr; u64 imm64; 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_ALU | BPF_SUB | BPF_K: /* (u32) dst -= (u32) imm */ case BPF_ALU64 | BPF_ADD | BPF_K: /* dst += imm */ case BPF_ALU64 | BPF_SUB | BPF_K: /* dst -= imm */ if (BPF_OP(code) == BPF_SUB) imm = -imm; if (imm) { 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_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; else if (imm == 1) goto bpf_alu32_trunc; 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_ALU | BPF_ARSH | BPF_X: /* (s32) dst >>= src */ PPC_SRAW(dst_reg, dst_reg, src_reg); goto bpf_alu32_trunc; case BPF_ALU64 | BPF_ARSH | BPF_X: /* (s64) dst >>= src */ PPC_SRAD(dst_reg, dst_reg, src_reg); break; case BPF_ALU | BPF_ARSH | BPF_K: /* (s32) dst >>= imm */ PPC_SRAWI(dst_reg, dst_reg, imm); goto bpf_alu32_trunc; 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(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; ret = bpf_jit_get_func_addr(fp, &insn[i], extra_pass, &func_addr, &func_addr_fixed); if (ret < 0) return ret; if (func_addr_fixed) bpf_jit_emit_func_call_hlp(image, ctx, func_addr); else bpf_jit_emit_func_call_rel(image, ctx, func_addr); /* 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: case BPF_JMP32 | BPF_JGT | BPF_K: case BPF_JMP32 | BPF_JGT | BPF_X: case BPF_JMP32 | BPF_JSGT | BPF_K: case BPF_JMP32 | 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: case BPF_JMP32 | BPF_JLT | BPF_K: case BPF_JMP32 | BPF_JLT | BPF_X: case BPF_JMP32 | BPF_JSLT | BPF_K: case BPF_JMP32 | 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: case BPF_JMP32 | BPF_JGE | BPF_K: case BPF_JMP32 | BPF_JGE | BPF_X: case BPF_JMP32 | BPF_JSGE | BPF_K: case BPF_JMP32 | 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: case BPF_JMP32 | BPF_JLE | BPF_K: case BPF_JMP32 | BPF_JLE | BPF_X: case BPF_JMP32 | BPF_JSLE | BPF_K: case BPF_JMP32 | 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: case BPF_JMP32 | BPF_JEQ | BPF_K: case BPF_JMP32 | 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: case BPF_JMP32 | BPF_JNE | BPF_K: case BPF_JMP32 | 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: case BPF_JMP32 | BPF_JSET | BPF_K: case BPF_JMP32 | 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: case BPF_JMP32 | BPF_JGT | BPF_X: case BPF_JMP32 | BPF_JLT | BPF_X: case BPF_JMP32 | BPF_JGE | BPF_X: case BPF_JMP32 | BPF_JLE | BPF_X: case BPF_JMP32 | BPF_JEQ | BPF_X: case BPF_JMP32 | BPF_JNE | BPF_X: /* unsigned comparison */ if (BPF_CLASS(code) == BPF_JMP32) PPC_CMPLW(dst_reg, src_reg); else 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: case BPF_JMP32 | BPF_JSGT | BPF_X: case BPF_JMP32 | BPF_JSLT | BPF_X: case BPF_JMP32 | BPF_JSGE | BPF_X: case BPF_JMP32 | BPF_JSLE | BPF_X: /* signed comparison */ if (BPF_CLASS(code) == BPF_JMP32) PPC_CMPW(dst_reg, src_reg); else PPC_CMPD(dst_reg, src_reg); break; case BPF_JMP | BPF_JSET | BPF_X: case BPF_JMP32 | BPF_JSET | BPF_X: if (BPF_CLASS(code) == BPF_JMP) { PPC_AND_DOT(b2p[TMP_REG_1], dst_reg, src_reg); } else { int tmp_reg = b2p[TMP_REG_1]; PPC_AND(tmp_reg, dst_reg, src_reg); PPC_RLWINM_DOT(tmp_reg, tmp_reg, 0, 0, 31); } 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: case BPF_JMP32 | BPF_JNE | BPF_K: case BPF_JMP32 | BPF_JEQ | BPF_K: case BPF_JMP32 | BPF_JGT | BPF_K: case BPF_JMP32 | BPF_JLT | BPF_K: case BPF_JMP32 | BPF_JGE | BPF_K: case BPF_JMP32 | BPF_JLE | BPF_K: { bool is_jmp32 = BPF_CLASS(code) == BPF_JMP32; /* * Need sign-extended load, so only positive * values can be used as imm in cmpldi */ if (imm >= 0 && imm < 32768) { if (is_jmp32) PPC_CMPLWI(dst_reg, imm); else PPC_CMPLDI(dst_reg, imm); } else { /* sign-extending load */ PPC_LI32(b2p[TMP_REG_1], imm); /* ... but unsigned comparison */ if (is_jmp32) PPC_CMPLW(dst_reg, b2p[TMP_REG_1]); else 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: case BPF_JMP32 | BPF_JSGT | BPF_K: case BPF_JMP32 | BPF_JSLT | BPF_K: case BPF_JMP32 | BPF_JSGE | BPF_K: case BPF_JMP32 | BPF_JSLE | BPF_K: { bool is_jmp32 = BPF_CLASS(code) == BPF_JMP32; /* * signed comparison, so any 16-bit value * can be used in cmpdi */ if (imm >= -32768 && imm < 32768) { if (is_jmp32) PPC_CMPWI(dst_reg, imm); else PPC_CMPDI(dst_reg, imm); } else { PPC_LI32(b2p[TMP_REG_1], imm); if (is_jmp32) PPC_CMPW(dst_reg, b2p[TMP_REG_1]); else PPC_CMPD(dst_reg, b2p[TMP_REG_1]); } break; } case BPF_JMP | BPF_JSET | BPF_K: case BPF_JMP32 | 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 { int tmp_reg = b2p[TMP_REG_1]; PPC_LI32(tmp_reg, imm); if (BPF_CLASS(code) == BPF_JMP) { PPC_AND_DOT(tmp_reg, dst_reg, tmp_reg); } else { PPC_AND(tmp_reg, dst_reg, tmp_reg); PPC_RLWINM_DOT(tmp_reg, tmp_reg, 0, 0, 31); } } break; } PPC_BCC(true_cond, addrs[i + 1 + off]); break; /* * Tail call */ case BPF_JMP | BPF_TAIL_CALL: ctx->seen |= SEEN_TAILCALL; bpf_jit_emit_tail_call(image, ctx, addrs[i + 1]); 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; } /* Fix the branch target addresses for subprog calls */ static int bpf_jit_fixup_subprog_calls(struct bpf_prog *fp, u32 *image, struct codegen_context *ctx, u32 *addrs) { const struct bpf_insn *insn = fp->insnsi; bool func_addr_fixed; u64 func_addr; u32 tmp_idx; int i, ret; for (i = 0; i < fp->len; i++) { /* * During the extra pass, only the branch target addresses for * the subprog calls need to be fixed. All other instructions * can left untouched. * * The JITed image length does not change because we already * ensure that the JITed instruction sequence for these calls * are of fixed length by padding them with NOPs. */ if (insn[i].code == (BPF_JMP | BPF_CALL) && insn[i].src_reg == BPF_PSEUDO_CALL) { ret = bpf_jit_get_func_addr(fp, &insn[i], true, &func_addr, &func_addr_fixed); if (ret < 0) return ret; /* * Save ctx->idx as this would currently point to the * end of the JITed image and set it to the offset of * the instruction sequence corresponding to the * subprog call temporarily. */ tmp_idx = ctx->idx; ctx->idx = addrs[i] / 4; bpf_jit_emit_func_call_rel(image, ctx, func_addr); /* * Restore ctx->idx here. This is safe as the length * of the JITed sequence remains unchanged. */ ctx->idx = tmp_idx; } } 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; } /* * 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); if (extra_pass) { /* * Do not touch the prologue and epilogue as they will remain * unchanged. Only fix the branch target address for subprog * calls in the body. * * This does not change the offsets and lengths of the subprog * call instruction sequences and hence, the size of the JITed * image as well. */ bpf_jit_fixup_subprog_calls(fp, code_base, &cgctx, addrs); /* There is no need to perform the usual passes. */ goto skip_codegen_passes; } /* 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); } skip_codegen_passes: 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) { bpf_prog_fill_jited_linfo(fp, addrs); 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); }
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