| // 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); |
| /* skip zero extension move, but set address map. */ |
| if (insn_is_zext(&insn[i + 1])) |
| addrs[++i] = ctx->idx * 4; |
| 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); |
| if (insn_is_zext(&insn[i + 1])) |
| addrs[++i] = ctx->idx * 4; |
| 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); |
| if (insn_is_zext(&insn[i + 1])) |
| addrs[++i] = ctx->idx * 4; |
| 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); |
| if (insn_is_zext(&insn[i + 1])) |
| addrs[++i] = ctx->idx * 4; |
| 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 */ |
| if (imm == 1) { |
| /* special mov32 for zext */ |
| PPC_RLWINM(dst_reg, dst_reg, 0, 0, 31); |
| break; |
| } |
| 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; |
| else if (insn_is_zext(&insn[i + 1])) |
| addrs[++i] = ctx->idx * 4; |
| break; |
| |
| bpf_alu32_trunc: |
| /* Truncate to 32-bits */ |
| if (BPF_CLASS(code) == BPF_ALU && !fp->aux->verifier_zext) |
| 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); |
| if (insn_is_zext(&insn[i + 1])) |
| addrs[++i] = ctx->idx * 4; |
| break; |
| case 32: |
| if (!fp->aux->verifier_zext) |
| /* 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); |
| if (insn_is_zext(&insn[i + 1])) |
| addrs[++i] = ctx->idx * 4; |
| break; |
| /* dst = *(u16 *)(ul) (src + off) */ |
| case BPF_LDX | BPF_MEM | BPF_H: |
| PPC_LHZ(dst_reg, src_reg, off); |
| if (insn_is_zext(&insn[i + 1])) |
| addrs[++i] = ctx->idx * 4; |
| break; |
| /* dst = *(u32 *)(ul) (src + off) */ |
| case BPF_LDX | BPF_MEM | BPF_W: |
| PPC_LWZ(dst_reg, src_reg, off); |
| if (insn_is_zext(&insn[i + 1])) |
| addrs[++i] = ctx->idx * 4; |
| 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; |
| }; |
| |
| bool bpf_jit_needs_zext(void) |
| { |
| return true; |
| } |
| |
| 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); |
| |
| 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); |
| } |