--- /dev/null
+/*
+ * Just-In-Time compiler for eBPF filters on MIPS
+ *
+ * Copyright (c) 2017 Cavium, Inc.
+ *
+ * Based on code from:
+ *
+ * Copyright (c) 2014 Imagination Technologies Ltd.
+ * Author: Markos Chandras <markos.chandras@imgtec.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.
+ */
+
+#include <linux/bitops.h>
+#include <linux/errno.h>
+#include <linux/filter.h>
+#include <linux/bpf.h>
+#include <linux/slab.h>
+#include <asm/bitops.h>
+#include <asm/byteorder.h>
+#include <asm/cacheflush.h>
+#include <asm/cpu-features.h>
+#include <asm/uasm.h>
+
+/* Registers used by JIT */
+#define MIPS_R_ZERO 0
+#define MIPS_R_AT 1
+#define MIPS_R_V0 2 /* BPF_R0 */
+#define MIPS_R_V1 3
+#define MIPS_R_A0 4 /* BPF_R1 */
+#define MIPS_R_A1 5 /* BPF_R2 */
+#define MIPS_R_A2 6 /* BPF_R3 */
+#define MIPS_R_A3 7 /* BPF_R4 */
+#define MIPS_R_A4 8 /* BPF_R5 */
+#define MIPS_R_T4 12 /* BPF_AX */
+#define MIPS_R_T5 13
+#define MIPS_R_T6 14
+#define MIPS_R_T7 15
+#define MIPS_R_S0 16 /* BPF_R6 */
+#define MIPS_R_S1 17 /* BPF_R7 */
+#define MIPS_R_S2 18 /* BPF_R8 */
+#define MIPS_R_S3 19 /* BPF_R9 */
+#define MIPS_R_S4 20 /* BPF_TCC */
+#define MIPS_R_S5 21
+#define MIPS_R_S6 22
+#define MIPS_R_S7 23
+#define MIPS_R_T8 24
+#define MIPS_R_T9 25
+#define MIPS_R_SP 29
+#define MIPS_R_RA 31
+
+/* eBPF flags */
+#define EBPF_SAVE_S0 BIT(0)
+#define EBPF_SAVE_S1 BIT(1)
+#define EBPF_SAVE_S2 BIT(2)
+#define EBPF_SAVE_S3 BIT(3)
+#define EBPF_SAVE_S4 BIT(4)
+#define EBPF_SAVE_RA BIT(5)
+#define EBPF_SEEN_FP BIT(6)
+#define EBPF_SEEN_TC BIT(7)
+#define EBPF_TCC_IN_V1 BIT(8)
+
+/*
+ * For the mips64 ISA, we need to track the value range or type for
+ * each JIT register. The BPF machine requires zero extended 32-bit
+ * values, but the mips64 ISA requires sign extended 32-bit values.
+ * At each point in the BPF program we track the state of every
+ * register so that we can zero extend or sign extend as the BPF
+ * semantics require.
+ */
+enum reg_val_type {
+ /* uninitialized */
+ REG_UNKNOWN,
+ /* not known to be 32-bit compatible. */
+ REG_64BIT,
+ /* 32-bit compatible, no truncation needed for 64-bit ops. */
+ REG_64BIT_32BIT,
+ /* 32-bit compatible, need truncation for 64-bit ops. */
+ REG_32BIT,
+ /* 32-bit zero extended. */
+ REG_32BIT_ZERO_EX,
+ /* 32-bit no sign/zero extension needed. */
+ REG_32BIT_POS
+};
+
+/*
+ * high bit of offsets indicates if long branch conversion done at
+ * this insn.
+ */
+#define OFFSETS_B_CONV BIT(31)
+
+/**
+ * struct jit_ctx - JIT context
+ * @skf: The sk_filter
+ * @stack_size: eBPF stack size
+ * @tmp_offset: eBPF $sp offset to 8-byte temporary memory
+ * @idx: Instruction index
+ * @flags: JIT flags
+ * @offsets: Instruction offsets
+ * @target: Memory location for the compiled filter
+ * @reg_val_types Packed enum reg_val_type for each register.
+ */
+struct jit_ctx {
+ const struct bpf_prog *skf;
+ int stack_size;
+ int tmp_offset;
+ u32 idx;
+ u32 flags;
+ u32 *offsets;
+ u32 *target;
+ u64 *reg_val_types;
+ unsigned int long_b_conversion:1;
+ unsigned int gen_b_offsets:1;
+};
+
+static void set_reg_val_type(u64 *rvt, int reg, enum reg_val_type type)
+{
+ *rvt &= ~(7ull << (reg * 3));
+ *rvt |= ((u64)type << (reg * 3));
+}
+
+static enum reg_val_type get_reg_val_type(const struct jit_ctx *ctx,
+ int index, int reg)
+{
+ return (ctx->reg_val_types[index] >> (reg * 3)) & 7;
+}
+
+/* Simply emit the instruction if the JIT memory space has been allocated */
+#define emit_instr(ctx, func, ...) \
+do { \
+ if ((ctx)->target != NULL) { \
+ u32 *p = &(ctx)->target[ctx->idx]; \
+ uasm_i_##func(&p, ##__VA_ARGS__); \
+ } \
+ (ctx)->idx++; \
+} while (0)
+
+static unsigned int j_target(struct jit_ctx *ctx, int target_idx)
+{
+ unsigned long target_va, base_va;
+ unsigned int r;
+
+ if (!ctx->target)
+ return 0;
+
+ base_va = (unsigned long)ctx->target;
+ target_va = base_va + (ctx->offsets[target_idx] & ~OFFSETS_B_CONV);
+
+ if ((base_va & ~0x0ffffffful) != (target_va & ~0x0ffffffful))
+ return (unsigned int)-1;
+ r = target_va & 0x0ffffffful;
+ return r;
+}
+
+/* Compute the immediate value for PC-relative branches. */
+static u32 b_imm(unsigned int tgt, struct jit_ctx *ctx)
+{
+ if (!ctx->gen_b_offsets)
+ return 0;
+
+ /*
+ * We want a pc-relative branch. tgt is the instruction offset
+ * we want to jump to.
+
+ * Branch on MIPS:
+ * I: target_offset <- sign_extend(offset)
+ * I+1: PC += target_offset (delay slot)
+ *
+ * ctx->idx currently points to the branch instruction
+ * but the offset is added to the delay slot so we need
+ * to subtract 4.
+ */
+ return (ctx->offsets[tgt] & ~OFFSETS_B_CONV) -
+ (ctx->idx * 4) - 4;
+}
+
+int bpf_jit_enable __read_mostly;
+
+enum which_ebpf_reg {
+ src_reg,
+ src_reg_no_fp,
+ dst_reg,
+ dst_reg_fp_ok
+};
+
+/*
+ * For eBPF, the register mapping naturally falls out of the
+ * requirements of eBPF and the MIPS n64 ABI. We don't maintain a
+ * separate frame pointer, so BPF_REG_10 relative accesses are
+ * adjusted to be $sp relative.
+ */
+int ebpf_to_mips_reg(struct jit_ctx *ctx, const struct bpf_insn *insn,
+ enum which_ebpf_reg w)
+{
+ int ebpf_reg = (w == src_reg || w == src_reg_no_fp) ?
+ insn->src_reg : insn->dst_reg;
+
+ switch (ebpf_reg) {
+ case BPF_REG_0:
+ return MIPS_R_V0;
+ case BPF_REG_1:
+ return MIPS_R_A0;
+ case BPF_REG_2:
+ return MIPS_R_A1;
+ case BPF_REG_3:
+ return MIPS_R_A2;
+ case BPF_REG_4:
+ return MIPS_R_A3;
+ case BPF_REG_5:
+ return MIPS_R_A4;
+ case BPF_REG_6:
+ ctx->flags |= EBPF_SAVE_S0;
+ return MIPS_R_S0;
+ case BPF_REG_7:
+ ctx->flags |= EBPF_SAVE_S1;
+ return MIPS_R_S1;
+ case BPF_REG_8:
+ ctx->flags |= EBPF_SAVE_S2;
+ return MIPS_R_S2;
+ case BPF_REG_9:
+ ctx->flags |= EBPF_SAVE_S3;
+ return MIPS_R_S3;
+ case BPF_REG_10:
+ if (w == dst_reg || w == src_reg_no_fp)
+ goto bad_reg;
+ ctx->flags |= EBPF_SEEN_FP;
+ /*
+ * Needs special handling, return something that
+ * cannot be clobbered just in case.
+ */
+ return MIPS_R_ZERO;
+ case BPF_REG_AX:
+ return MIPS_R_T4;
+ default:
+bad_reg:
+ WARN(1, "Illegal bpf reg: %d\n", ebpf_reg);
+ return -EINVAL;
+ }
+}
+/*
+ * eBPF stack frame will be something like:
+ *
+ * Entry $sp ------> +--------------------------------+
+ * | $ra (optional) |
+ * +--------------------------------+
+ * | $s0 (optional) |
+ * +--------------------------------+
+ * | $s1 (optional) |
+ * +--------------------------------+
+ * | $s2 (optional) |
+ * +--------------------------------+
+ * | $s3 (optional) |
+ * +--------------------------------+
+ * | $s4 (optional) |
+ * +--------------------------------+
+ * | tmp-storage (if $ra saved) |
+ * $sp + tmp_offset --> +--------------------------------+ <--BPF_REG_10
+ * | BPF_REG_10 relative storage |
+ * | MAX_BPF_STACK (optional) |
+ * | . |
+ * | . |
+ * | . |
+ * $sp --------> +--------------------------------+
+ *
+ * If BPF_REG_10 is never referenced, then the MAX_BPF_STACK sized
+ * area is not allocated.
+ */
+static int gen_int_prologue(struct jit_ctx *ctx)
+{
+ int stack_adjust = 0;
+ int store_offset;
+ int locals_size;
+
+ if (ctx->flags & EBPF_SAVE_RA)
+ /*
+ * If RA we are doing a function call and may need
+ * extra 8-byte tmp area.
+ */
+ stack_adjust += 16;
+ if (ctx->flags & EBPF_SAVE_S0)
+ stack_adjust += 8;
+ if (ctx->flags & EBPF_SAVE_S1)
+ stack_adjust += 8;
+ if (ctx->flags & EBPF_SAVE_S2)
+ stack_adjust += 8;
+ if (ctx->flags & EBPF_SAVE_S3)
+ stack_adjust += 8;
+ if (ctx->flags & EBPF_SAVE_S4)
+ stack_adjust += 8;
+
+ BUILD_BUG_ON(MAX_BPF_STACK & 7);
+ locals_size = (ctx->flags & EBPF_SEEN_FP) ? MAX_BPF_STACK : 0;
+
+ stack_adjust += locals_size;
+ ctx->tmp_offset = locals_size;
+
+ ctx->stack_size = stack_adjust;
+
+ /*
+ * First instruction initializes the tail call count (TCC).
+ * On tail call we skip this instruction, and the TCC is
+ * passed in $v1 from the caller.
+ */
+ emit_instr(ctx, daddiu, MIPS_R_V1, MIPS_R_ZERO, MAX_TAIL_CALL_CNT);
+ if (stack_adjust)
+ emit_instr(ctx, daddiu, MIPS_R_SP, MIPS_R_SP, -stack_adjust);
+ else
+ return 0;
+
+ store_offset = stack_adjust - 8;
+
+ if (ctx->flags & EBPF_SAVE_RA) {
+ emit_instr(ctx, sd, MIPS_R_RA, store_offset, MIPS_R_SP);
+ store_offset -= 8;
+ }
+ if (ctx->flags & EBPF_SAVE_S0) {
+ emit_instr(ctx, sd, MIPS_R_S0, store_offset, MIPS_R_SP);
+ store_offset -= 8;
+ }
+ if (ctx->flags & EBPF_SAVE_S1) {
+ emit_instr(ctx, sd, MIPS_R_S1, store_offset, MIPS_R_SP);
+ store_offset -= 8;
+ }
+ if (ctx->flags & EBPF_SAVE_S2) {
+ emit_instr(ctx, sd, MIPS_R_S2, store_offset, MIPS_R_SP);
+ store_offset -= 8;
+ }
+ if (ctx->flags & EBPF_SAVE_S3) {
+ emit_instr(ctx, sd, MIPS_R_S3, store_offset, MIPS_R_SP);
+ store_offset -= 8;
+ }
+ if (ctx->flags & EBPF_SAVE_S4) {
+ emit_instr(ctx, sd, MIPS_R_S4, store_offset, MIPS_R_SP);
+ store_offset -= 8;
+ }
+
+ if ((ctx->flags & EBPF_SEEN_TC) && !(ctx->flags & EBPF_TCC_IN_V1))
+ emit_instr(ctx, daddu, MIPS_R_S4, MIPS_R_V1, MIPS_R_ZERO);
+
+ return 0;
+}
+
+static int build_int_epilogue(struct jit_ctx *ctx, int dest_reg)
+{
+ const struct bpf_prog *prog = ctx->skf;
+ int stack_adjust = ctx->stack_size;
+ int store_offset = stack_adjust - 8;
+ int r0 = MIPS_R_V0;
+
+ if (dest_reg == MIPS_R_RA &&
+ get_reg_val_type(ctx, prog->len, BPF_REG_0) == REG_32BIT_ZERO_EX)
+ /* Don't let zero extended value escape. */
+ emit_instr(ctx, sll, r0, r0, 0);
+
+ if (ctx->flags & EBPF_SAVE_RA) {
+ emit_instr(ctx, ld, MIPS_R_RA, store_offset, MIPS_R_SP);
+ store_offset -= 8;
+ }
+ if (ctx->flags & EBPF_SAVE_S0) {
+ emit_instr(ctx, ld, MIPS_R_S0, store_offset, MIPS_R_SP);
+ store_offset -= 8;
+ }
+ if (ctx->flags & EBPF_SAVE_S1) {
+ emit_instr(ctx, ld, MIPS_R_S1, store_offset, MIPS_R_SP);
+ store_offset -= 8;
+ }
+ if (ctx->flags & EBPF_SAVE_S2) {
+ emit_instr(ctx, ld, MIPS_R_S2, store_offset, MIPS_R_SP);
+ store_offset -= 8;
+ }
+ if (ctx->flags & EBPF_SAVE_S3) {
+ emit_instr(ctx, ld, MIPS_R_S3, store_offset, MIPS_R_SP);
+ store_offset -= 8;
+ }
+ if (ctx->flags & EBPF_SAVE_S4) {
+ emit_instr(ctx, ld, MIPS_R_S4, store_offset, MIPS_R_SP);
+ store_offset -= 8;
+ }
+ emit_instr(ctx, jr, dest_reg);
+
+ if (stack_adjust)
+ emit_instr(ctx, daddiu, MIPS_R_SP, MIPS_R_SP, stack_adjust);
+ else
+ emit_instr(ctx, nop);
+
+ return 0;
+}
+
+static void gen_imm_to_reg(const struct bpf_insn *insn, int reg,
+ struct jit_ctx *ctx)
+{
+ if (insn->imm >= S16_MIN && insn->imm <= S16_MAX) {
+ emit_instr(ctx, addiu, reg, MIPS_R_ZERO, insn->imm);
+ } else {
+ int lower = (s16)(insn->imm & 0xffff);
+ int upper = insn->imm - lower;
+
+ emit_instr(ctx, lui, reg, upper >> 16);
+ emit_instr(ctx, addiu, reg, reg, lower);
+ }
+
+}
+
+static int gen_imm_insn(const struct bpf_insn *insn, struct jit_ctx *ctx,
+ int idx)
+{
+ int upper_bound, lower_bound;
+ int dst = ebpf_to_mips_reg(ctx, insn, dst_reg);
+
+ if (dst < 0)
+ return dst;
+
+ switch (BPF_OP(insn->code)) {
+ case BPF_MOV:
+ case BPF_ADD:
+ upper_bound = S16_MAX;
+ lower_bound = S16_MIN;
+ break;
+ case BPF_SUB:
+ upper_bound = -(int)S16_MIN;
+ lower_bound = -(int)S16_MAX;
+ break;
+ case BPF_AND:
+ case BPF_OR:
+ case BPF_XOR:
+ upper_bound = 0xffff;
+ lower_bound = 0;
+ break;
+ case BPF_RSH:
+ case BPF_LSH:
+ case BPF_ARSH:
+ /* Shift amounts are truncated, no need for bounds */
+ upper_bound = S32_MAX;
+ lower_bound = S32_MIN;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ /*
+ * Immediate move clobbers the register, so no sign/zero
+ * extension needed.
+ */
+ if (BPF_CLASS(insn->code) == BPF_ALU64 &&
+ BPF_OP(insn->code) != BPF_MOV &&
+ get_reg_val_type(ctx, idx, insn->dst_reg) == REG_32BIT)
+ emit_instr(ctx, dinsu, dst, MIPS_R_ZERO, 32, 32);
+ /* BPF_ALU | BPF_LSH doesn't need separate sign extension */
+ if (BPF_CLASS(insn->code) == BPF_ALU &&
+ BPF_OP(insn->code) != BPF_LSH &&
+ BPF_OP(insn->code) != BPF_MOV &&
+ get_reg_val_type(ctx, idx, insn->dst_reg) != REG_32BIT)
+ emit_instr(ctx, sll, dst, dst, 0);
+
+ if (insn->imm >= lower_bound && insn->imm <= upper_bound) {
+ /* single insn immediate case */
+ switch (BPF_OP(insn->code) | BPF_CLASS(insn->code)) {
+ case BPF_ALU64 | BPF_MOV:
+ emit_instr(ctx, daddiu, dst, MIPS_R_ZERO, insn->imm);
+ break;
+ case BPF_ALU64 | BPF_AND:
+ case BPF_ALU | BPF_AND:
+ emit_instr(ctx, andi, dst, dst, insn->imm);
+ break;
+ case BPF_ALU64 | BPF_OR:
+ case BPF_ALU | BPF_OR:
+ emit_instr(ctx, ori, dst, dst, insn->imm);
+ break;
+ case BPF_ALU64 | BPF_XOR:
+ case BPF_ALU | BPF_XOR:
+ emit_instr(ctx, xori, dst, dst, insn->imm);
+ break;
+ case BPF_ALU64 | BPF_ADD:
+ emit_instr(ctx, daddiu, dst, dst, insn->imm);
+ break;
+ case BPF_ALU64 | BPF_SUB:
+ emit_instr(ctx, daddiu, dst, dst, -insn->imm);
+ break;
+ case BPF_ALU64 | BPF_RSH:
+ emit_instr(ctx, dsrl_safe, dst, dst, insn->imm & 0x3f);
+ break;
+ case BPF_ALU | BPF_RSH:
+ emit_instr(ctx, srl, dst, dst, insn->imm & 0x1f);
+ break;
+ case BPF_ALU64 | BPF_LSH:
+ emit_instr(ctx, dsll_safe, dst, dst, insn->imm & 0x3f);
+ break;
+ case BPF_ALU | BPF_LSH:
+ emit_instr(ctx, sll, dst, dst, insn->imm & 0x1f);
+ break;
+ case BPF_ALU64 | BPF_ARSH:
+ emit_instr(ctx, dsra_safe, dst, dst, insn->imm & 0x3f);
+ break;
+ case BPF_ALU | BPF_ARSH:
+ emit_instr(ctx, sra, dst, dst, insn->imm & 0x1f);
+ break;
+ case BPF_ALU | BPF_MOV:
+ emit_instr(ctx, addiu, dst, MIPS_R_ZERO, insn->imm);
+ break;
+ case BPF_ALU | BPF_ADD:
+ emit_instr(ctx, addiu, dst, dst, insn->imm);
+ break;
+ case BPF_ALU | BPF_SUB:
+ emit_instr(ctx, addiu, dst, dst, -insn->imm);
+ break;
+ default:
+ return -EINVAL;
+ }
+ } else {
+ /* multi insn immediate case */
+ if (BPF_OP(insn->code) == BPF_MOV) {
+ gen_imm_to_reg(insn, dst, ctx);
+ } else {
+ gen_imm_to_reg(insn, MIPS_R_AT, ctx);
+ switch (BPF_OP(insn->code) | BPF_CLASS(insn->code)) {
+ case BPF_ALU64 | BPF_AND:
+ case BPF_ALU | BPF_AND:
+ emit_instr(ctx, and, dst, dst, MIPS_R_AT);
+ break;
+ case BPF_ALU64 | BPF_OR:
+ case BPF_ALU | BPF_OR:
+ emit_instr(ctx, or, dst, dst, MIPS_R_AT);
+ break;
+ case BPF_ALU64 | BPF_XOR:
+ case BPF_ALU | BPF_XOR:
+ emit_instr(ctx, xor, dst, dst, MIPS_R_AT);
+ break;
+ case BPF_ALU64 | BPF_ADD:
+ emit_instr(ctx, daddu, dst, dst, MIPS_R_AT);
+ break;
+ case BPF_ALU64 | BPF_SUB:
+ emit_instr(ctx, dsubu, dst, dst, MIPS_R_AT);
+ break;
+ case BPF_ALU | BPF_ADD:
+ emit_instr(ctx, addu, dst, dst, MIPS_R_AT);
+ break;
+ case BPF_ALU | BPF_SUB:
+ emit_instr(ctx, subu, dst, dst, MIPS_R_AT);
+ break;
+ default:
+ return -EINVAL;
+ }
+ }
+ }
+
+ return 0;
+}
+
+static void * __must_check
+ool_skb_header_pointer(const struct sk_buff *skb, int offset,
+ int len, void *buffer)
+{
+ return skb_header_pointer(skb, offset, len, buffer);
+}
+
+static int size_to_len(const struct bpf_insn *insn)
+{
+ switch (BPF_SIZE(insn->code)) {
+ case BPF_B:
+ return 1;
+ case BPF_H:
+ return 2;
+ case BPF_W:
+ return 4;
+ case BPF_DW:
+ return 8;
+ }
+ return 0;
+}
+
+static void emit_const_to_reg(struct jit_ctx *ctx, int dst, u64 value)
+{
+ if (value >= 0xffffffffffff8000ull || value < 0x8000ull) {
+ emit_instr(ctx, daddiu, dst, MIPS_R_ZERO, (int)value);
+ } else if (value >= 0xffffffff80000000ull ||
+ (value < 0x80000000 && value > 0xffff)) {
+ emit_instr(ctx, lui, dst, (s32)(s16)(value >> 16));
+ emit_instr(ctx, ori, dst, dst, (unsigned int)(value & 0xffff));
+ } else {
+ int i;
+ bool seen_part = false;
+ int needed_shift = 0;
+
+ for (i = 0; i < 4; i++) {
+ u64 part = (value >> (16 * (3 - i))) & 0xffff;
+
+ if (seen_part && needed_shift > 0 && (part || i == 3)) {
+ emit_instr(ctx, dsll_safe, dst, dst, needed_shift);
+ needed_shift = 0;
+ }
+ if (part) {
+ if (i == 0 || (!seen_part && i < 3 && part < 0x8000)) {
+ emit_instr(ctx, lui, dst, (s32)(s16)part);
+ needed_shift = -16;
+ } else {
+ emit_instr(ctx, ori, dst,
+ seen_part ? dst : MIPS_R_ZERO,
+ (unsigned int)part);
+ }
+ seen_part = true;
+ }
+ if (seen_part)
+ needed_shift += 16;
+ }
+ }
+}
+
+static int emit_bpf_tail_call(struct jit_ctx *ctx, int this_idx)
+{
+ int off, b_off;
+
+ ctx->flags |= EBPF_SEEN_TC;
+ /*
+ * if (index >= array->map.max_entries)
+ * goto out;
+ */
+ off = offsetof(struct bpf_array, map.max_entries);
+ emit_instr(ctx, lwu, MIPS_R_T5, off, MIPS_R_A1);
+ emit_instr(ctx, sltu, MIPS_R_AT, MIPS_R_T5, MIPS_R_A2);
+ b_off = b_imm(this_idx + 1, ctx);
+ emit_instr(ctx, bne, MIPS_R_AT, MIPS_R_ZERO, b_off);
+ /*
+ * if (--TCC < 0)
+ * goto out;
+ */
+ /* Delay slot */
+ emit_instr(ctx, daddiu, MIPS_R_T5,
+ (ctx->flags & EBPF_TCC_IN_V1) ? MIPS_R_V1 : MIPS_R_S4, -1);
+ b_off = b_imm(this_idx + 1, ctx);
+ emit_instr(ctx, bltz, MIPS_R_T5, b_off);
+ /*
+ * prog = array->ptrs[index];
+ * if (prog == NULL)
+ * goto out;
+ */
+ /* Delay slot */
+ emit_instr(ctx, dsll, MIPS_R_T8, MIPS_R_A2, 3);
+ emit_instr(ctx, daddu, MIPS_R_T8, MIPS_R_T8, MIPS_R_A1);
+ off = offsetof(struct bpf_array, ptrs);
+ emit_instr(ctx, ld, MIPS_R_AT, off, MIPS_R_T8);
+ b_off = b_imm(this_idx + 1, ctx);
+ emit_instr(ctx, beq, MIPS_R_AT, MIPS_R_ZERO, b_off);
+ /* Delay slot */
+ emit_instr(ctx, nop);
+
+ /* goto *(prog->bpf_func + 4); */
+ off = offsetof(struct bpf_prog, bpf_func);
+ emit_instr(ctx, ld, MIPS_R_T9, off, MIPS_R_AT);
+ /* All systems are go... propagate TCC */
+ emit_instr(ctx, daddu, MIPS_R_V1, MIPS_R_T5, MIPS_R_ZERO);
+ /* Skip first instruction (TCC initialization) */
+ emit_instr(ctx, daddiu, MIPS_R_T9, MIPS_R_T9, 4);
+ return build_int_epilogue(ctx, MIPS_R_T9);
+}
+
+static bool use_bbit_insns(void)
+{
+ switch (current_cpu_type()) {
+ case CPU_CAVIUM_OCTEON:
+ case CPU_CAVIUM_OCTEON_PLUS:
+ case CPU_CAVIUM_OCTEON2:
+ case CPU_CAVIUM_OCTEON3:
+ return true;
+ default:
+ return false;
+ }
+}
+
+static bool is_bad_offset(int b_off)
+{
+ return b_off > 0x1ffff || b_off < -0x20000;
+}
+
+/* Returns the number of insn slots consumed. */
+static int build_one_insn(const struct bpf_insn *insn, struct jit_ctx *ctx,
+ int this_idx, int exit_idx)
+{
+ int src, dst, r, td, ts, mem_off, b_off;
+ bool need_swap, did_move, cmp_eq;
+ unsigned int target;
+ u64 t64;
+ s64 t64s;
+
+ switch (insn->code) {
+ case BPF_ALU64 | BPF_ADD | BPF_K: /* ALU64_IMM */
+ case BPF_ALU64 | BPF_SUB | BPF_K: /* ALU64_IMM */
+ case BPF_ALU64 | BPF_OR | BPF_K: /* ALU64_IMM */
+ case BPF_ALU64 | BPF_AND | BPF_K: /* ALU64_IMM */
+ case BPF_ALU64 | BPF_LSH | BPF_K: /* ALU64_IMM */
+ case BPF_ALU64 | BPF_RSH | BPF_K: /* ALU64_IMM */
+ case BPF_ALU64 | BPF_XOR | BPF_K: /* ALU64_IMM */
+ case BPF_ALU64 | BPF_ARSH | BPF_K: /* ALU64_IMM */
+ case BPF_ALU64 | BPF_MOV | BPF_K: /* ALU64_IMM */
+ case BPF_ALU | BPF_MOV | BPF_K: /* ALU32_IMM */
+ case BPF_ALU | BPF_ADD | BPF_K: /* ALU32_IMM */
+ case BPF_ALU | BPF_SUB | BPF_K: /* ALU32_IMM */
+ case BPF_ALU | BPF_OR | BPF_K: /* ALU64_IMM */
+ case BPF_ALU | BPF_AND | BPF_K: /* ALU64_IMM */
+ case BPF_ALU | BPF_LSH | BPF_K: /* ALU64_IMM */
+ case BPF_ALU | BPF_RSH | BPF_K: /* ALU64_IMM */
+ case BPF_ALU | BPF_XOR | BPF_K: /* ALU64_IMM */
+ case BPF_ALU | BPF_ARSH | BPF_K: /* ALU64_IMM */
+ r = gen_imm_insn(insn, ctx, this_idx);
+ if (r < 0)
+ return r;
+ break;
+ case BPF_ALU64 | BPF_MUL | BPF_K: /* ALU64_IMM */
+ dst = ebpf_to_mips_reg(ctx, insn, dst_reg);
+ if (dst < 0)
+ return dst;
+ if (get_reg_val_type(ctx, this_idx, insn->dst_reg) == REG_32BIT)
+ emit_instr(ctx, dinsu, dst, MIPS_R_ZERO, 32, 32);
+ if (insn->imm == 1) /* Mult by 1 is a nop */
+ break;
+ gen_imm_to_reg(insn, MIPS_R_AT, ctx);
+ emit_instr(ctx, dmultu, MIPS_R_AT, dst);
+ emit_instr(ctx, mflo, dst);
+ break;
+ case BPF_ALU64 | BPF_NEG | BPF_K: /* ALU64_IMM */
+ dst = ebpf_to_mips_reg(ctx, insn, dst_reg);
+ if (dst < 0)
+ return dst;
+ if (get_reg_val_type(ctx, this_idx, insn->dst_reg) == REG_32BIT)
+ emit_instr(ctx, dinsu, dst, MIPS_R_ZERO, 32, 32);
+ emit_instr(ctx, dsubu, dst, MIPS_R_ZERO, dst);
+ break;
+ case BPF_ALU | BPF_MUL | BPF_K: /* ALU_IMM */
+ dst = ebpf_to_mips_reg(ctx, insn, dst_reg);
+ if (dst < 0)
+ return dst;
+ td = get_reg_val_type(ctx, this_idx, insn->dst_reg);
+ if (td == REG_64BIT || td == REG_32BIT_ZERO_EX) {
+ /* sign extend */
+ emit_instr(ctx, sll, dst, dst, 0);
+ }
+ if (insn->imm == 1) /* Mult by 1 is a nop */
+ break;
+ gen_imm_to_reg(insn, MIPS_R_AT, ctx);
+ emit_instr(ctx, multu, dst, MIPS_R_AT);
+ emit_instr(ctx, mflo, dst);
+ break;
+ case BPF_ALU | BPF_NEG | BPF_K: /* ALU_IMM */
+ dst = ebpf_to_mips_reg(ctx, insn, dst_reg);
+ if (dst < 0)
+ return dst;
+ td = get_reg_val_type(ctx, this_idx, insn->dst_reg);
+ if (td == REG_64BIT || td == REG_32BIT_ZERO_EX) {
+ /* sign extend */
+ emit_instr(ctx, sll, dst, dst, 0);
+ }
+ emit_instr(ctx, subu, dst, MIPS_R_ZERO, dst);
+ break;
+ case BPF_ALU | BPF_DIV | BPF_K: /* ALU_IMM */
+ case BPF_ALU | BPF_MOD | BPF_K: /* ALU_IMM */
+ dst = ebpf_to_mips_reg(ctx, insn, dst_reg);
+ if (dst < 0)
+ return dst;
+ if (insn->imm == 0) { /* Div by zero */
+ b_off = b_imm(exit_idx, ctx);
+ if (is_bad_offset(b_off))
+ return -E2BIG;
+ emit_instr(ctx, beq, MIPS_R_ZERO, MIPS_R_ZERO, b_off);
+ emit_instr(ctx, addu, MIPS_R_V0, MIPS_R_ZERO, MIPS_R_ZERO);
+ }
+ td = get_reg_val_type(ctx, this_idx, insn->dst_reg);
+ if (td == REG_64BIT || td == REG_32BIT_ZERO_EX)
+ /* sign extend */
+ emit_instr(ctx, sll, dst, dst, 0);
+ if (insn->imm == 1) {
+ /* div by 1 is a nop, mod by 1 is zero */
+ if (BPF_OP(insn->code) == BPF_MOD)
+ emit_instr(ctx, addu, dst, MIPS_R_ZERO, MIPS_R_ZERO);
+ break;
+ }
+ gen_imm_to_reg(insn, MIPS_R_AT, ctx);
+ emit_instr(ctx, divu, dst, MIPS_R_AT);
+ if (BPF_OP(insn->code) == BPF_DIV)
+ emit_instr(ctx, mflo, dst);
+ else
+ emit_instr(ctx, mfhi, dst);
+ break;
+ case BPF_ALU64 | BPF_DIV | BPF_K: /* ALU_IMM */
+ case BPF_ALU64 | BPF_MOD | BPF_K: /* ALU_IMM */
+ dst = ebpf_to_mips_reg(ctx, insn, dst_reg);
+ if (dst < 0)
+ return dst;
+ if (insn->imm == 0) { /* Div by zero */
+ b_off = b_imm(exit_idx, ctx);
+ if (is_bad_offset(b_off))
+ return -E2BIG;
+ emit_instr(ctx, beq, MIPS_R_ZERO, MIPS_R_ZERO, b_off);
+ emit_instr(ctx, addu, MIPS_R_V0, MIPS_R_ZERO, MIPS_R_ZERO);
+ }
+ if (get_reg_val_type(ctx, this_idx, insn->dst_reg) == REG_32BIT)
+ emit_instr(ctx, dinsu, dst, MIPS_R_ZERO, 32, 32);
+
+ if (insn->imm == 1) {
+ /* div by 1 is a nop, mod by 1 is zero */
+ if (BPF_OP(insn->code) == BPF_MOD)
+ emit_instr(ctx, addu, dst, MIPS_R_ZERO, MIPS_R_ZERO);
+ break;
+ }
+ gen_imm_to_reg(insn, MIPS_R_AT, ctx);
+ emit_instr(ctx, ddivu, dst, MIPS_R_AT);
+ if (BPF_OP(insn->code) == BPF_DIV)
+ emit_instr(ctx, mflo, dst);
+ else
+ emit_instr(ctx, mfhi, dst);
+ break;
+ case BPF_ALU64 | BPF_MOV | BPF_X: /* ALU64_REG */
+ case BPF_ALU64 | BPF_ADD | BPF_X: /* ALU64_REG */
+ case BPF_ALU64 | BPF_SUB | BPF_X: /* ALU64_REG */
+ case BPF_ALU64 | BPF_XOR | BPF_X: /* ALU64_REG */
+ case BPF_ALU64 | BPF_OR | BPF_X: /* ALU64_REG */
+ case BPF_ALU64 | BPF_AND | BPF_X: /* ALU64_REG */
+ case BPF_ALU64 | BPF_MUL | BPF_X: /* ALU64_REG */
+ case BPF_ALU64 | BPF_DIV | BPF_X: /* ALU64_REG */
+ case BPF_ALU64 | BPF_MOD | BPF_X: /* ALU64_REG */
+ case BPF_ALU64 | BPF_LSH | BPF_X: /* ALU64_REG */
+ case BPF_ALU64 | BPF_RSH | BPF_X: /* ALU64_REG */
+ case BPF_ALU64 | BPF_ARSH | BPF_X: /* ALU64_REG */
+ src = ebpf_to_mips_reg(ctx, insn, src_reg);
+ dst = ebpf_to_mips_reg(ctx, insn, dst_reg);
+ if (src < 0 || dst < 0)
+ return -EINVAL;
+ if (get_reg_val_type(ctx, this_idx, insn->dst_reg) == REG_32BIT)
+ emit_instr(ctx, dinsu, dst, MIPS_R_ZERO, 32, 32);
+ did_move = false;
+ if (insn->src_reg == BPF_REG_10) {
+ if (BPF_OP(insn->code) == BPF_MOV) {
+ emit_instr(ctx, daddiu, dst, MIPS_R_SP, MAX_BPF_STACK);
+ did_move = true;
+ } else {
+ emit_instr(ctx, daddiu, MIPS_R_AT, MIPS_R_SP, MAX_BPF_STACK);
+ src = MIPS_R_AT;
+ }
+ } else if (get_reg_val_type(ctx, this_idx, insn->src_reg) == REG_32BIT) {
+ int tmp_reg = MIPS_R_AT;
+
+ if (BPF_OP(insn->code) == BPF_MOV) {
+ tmp_reg = dst;
+ did_move = true;
+ }
+ emit_instr(ctx, daddu, tmp_reg, src, MIPS_R_ZERO);
+ emit_instr(ctx, dinsu, tmp_reg, MIPS_R_ZERO, 32, 32);
+ src = MIPS_R_AT;
+ }
+ switch (BPF_OP(insn->code)) {
+ case BPF_MOV:
+ if (!did_move)
+ emit_instr(ctx, daddu, dst, src, MIPS_R_ZERO);
+ break;
+ case BPF_ADD:
+ emit_instr(ctx, daddu, dst, dst, src);
+ break;
+ case BPF_SUB:
+ emit_instr(ctx, dsubu, dst, dst, src);
+ break;
+ case BPF_XOR:
+ emit_instr(ctx, xor, dst, dst, src);
+ break;
+ case BPF_OR:
+ emit_instr(ctx, or, dst, dst, src);
+ break;
+ case BPF_AND:
+ emit_instr(ctx, and, dst, dst, src);
+ break;
+ case BPF_MUL:
+ emit_instr(ctx, dmultu, dst, src);
+ emit_instr(ctx, mflo, dst);
+ break;
+ case BPF_DIV:
+ case BPF_MOD:
+ b_off = b_imm(exit_idx, ctx);
+ if (is_bad_offset(b_off))
+ return -E2BIG;
+ emit_instr(ctx, beq, src, MIPS_R_ZERO, b_off);
+ emit_instr(ctx, movz, MIPS_R_V0, MIPS_R_ZERO, src);
+ emit_instr(ctx, ddivu, dst, src);
+ if (BPF_OP(insn->code) == BPF_DIV)
+ emit_instr(ctx, mflo, dst);
+ else
+ emit_instr(ctx, mfhi, dst);
+ break;
+ case BPF_LSH:
+ emit_instr(ctx, dsllv, dst, dst, src);
+ break;
+ case BPF_RSH:
+ emit_instr(ctx, dsrlv, dst, dst, src);
+ break;
+ case BPF_ARSH:
+ emit_instr(ctx, dsrav, dst, dst, src);
+ break;
+ default:
+ pr_err("ALU64_REG NOT HANDLED\n");
+ return -EINVAL;
+ }
+ break;
+ case BPF_ALU | BPF_MOV | BPF_X: /* ALU_REG */
+ case BPF_ALU | BPF_ADD | BPF_X: /* ALU_REG */
+ case BPF_ALU | BPF_SUB | BPF_X: /* ALU_REG */
+ case BPF_ALU | BPF_XOR | BPF_X: /* ALU_REG */
+ case BPF_ALU | BPF_OR | BPF_X: /* ALU_REG */
+ case BPF_ALU | BPF_AND | BPF_X: /* ALU_REG */
+ case BPF_ALU | BPF_MUL | BPF_X: /* ALU_REG */
+ case BPF_ALU | BPF_DIV | BPF_X: /* ALU_REG */
+ case BPF_ALU | BPF_MOD | BPF_X: /* ALU_REG */
+ case BPF_ALU | BPF_LSH | BPF_X: /* ALU_REG */
+ case BPF_ALU | BPF_RSH | BPF_X: /* ALU_REG */
+ src = ebpf_to_mips_reg(ctx, insn, src_reg_no_fp);
+ dst = ebpf_to_mips_reg(ctx, insn, dst_reg);
+ if (src < 0 || dst < 0)
+ return -EINVAL;
+ td = get_reg_val_type(ctx, this_idx, insn->dst_reg);
+ if (td == REG_64BIT || td == REG_32BIT_ZERO_EX) {
+ /* sign extend */
+ emit_instr(ctx, sll, dst, dst, 0);
+ }
+ did_move = false;
+ ts = get_reg_val_type(ctx, this_idx, insn->src_reg);
+ if (ts == REG_64BIT || ts == REG_32BIT_ZERO_EX) {
+ int tmp_reg = MIPS_R_AT;
+
+ if (BPF_OP(insn->code) == BPF_MOV) {
+ tmp_reg = dst;
+ did_move = true;
+ }
+ /* sign extend */
+ emit_instr(ctx, sll, tmp_reg, src, 0);
+ src = MIPS_R_AT;
+ }
+ switch (BPF_OP(insn->code)) {
+ case BPF_MOV:
+ if (!did_move)
+ emit_instr(ctx, addu, dst, src, MIPS_R_ZERO);
+ break;
+ case BPF_ADD:
+ emit_instr(ctx, addu, dst, dst, src);
+ break;
+ case BPF_SUB:
+ emit_instr(ctx, subu, dst, dst, src);
+ break;
+ case BPF_XOR:
+ emit_instr(ctx, xor, dst, dst, src);
+ break;
+ case BPF_OR:
+ emit_instr(ctx, or, dst, dst, src);
+ break;
+ case BPF_AND:
+ emit_instr(ctx, and, dst, dst, src);
+ break;
+ case BPF_MUL:
+ emit_instr(ctx, mul, dst, dst, src);
+ break;
+ case BPF_DIV:
+ case BPF_MOD:
+ b_off = b_imm(exit_idx, ctx);
+ if (is_bad_offset(b_off))
+ return -E2BIG;
+ emit_instr(ctx, beq, src, MIPS_R_ZERO, b_off);
+ emit_instr(ctx, movz, MIPS_R_V0, MIPS_R_ZERO, src);
+ emit_instr(ctx, divu, dst, src);
+ if (BPF_OP(insn->code) == BPF_DIV)
+ emit_instr(ctx, mflo, dst);
+ else
+ emit_instr(ctx, mfhi, dst);
+ break;
+ case BPF_LSH:
+ emit_instr(ctx, sllv, dst, dst, src);
+ break;
+ case BPF_RSH:
+ emit_instr(ctx, srlv, dst, dst, src);
+ break;
+ default:
+ pr_err("ALU_REG NOT HANDLED\n");
+ return -EINVAL;
+ }
+ break;
+ case BPF_JMP | BPF_EXIT:
+ if (this_idx + 1 < exit_idx) {
+ b_off = b_imm(exit_idx, ctx);
+ if (is_bad_offset(b_off))
+ return -E2BIG;
+ emit_instr(ctx, beq, MIPS_R_ZERO, MIPS_R_ZERO, b_off);
+ emit_instr(ctx, nop);
+ }
+ break;
+ case BPF_JMP | BPF_JEQ | BPF_K: /* JMP_IMM */
+ case BPF_JMP | BPF_JNE | BPF_K: /* JMP_IMM */
+ cmp_eq = (BPF_OP(insn->code) == BPF_JEQ);
+ dst = ebpf_to_mips_reg(ctx, insn, dst_reg_fp_ok);
+ if (dst < 0)
+ return dst;
+ if (insn->imm == 0) {
+ src = MIPS_R_ZERO;
+ } else {
+ gen_imm_to_reg(insn, MIPS_R_AT, ctx);
+ src = MIPS_R_AT;
+ }
+ goto jeq_common;
+ case BPF_JMP | BPF_JEQ | BPF_X: /* JMP_REG */
+ case BPF_JMP | BPF_JNE | BPF_X:
+ case BPF_JMP | BPF_JSGT | BPF_X:
+ case BPF_JMP | BPF_JSGE | BPF_X:
+ case BPF_JMP | BPF_JGT | BPF_X:
+ case BPF_JMP | BPF_JGE | BPF_X:
+ case BPF_JMP | BPF_JSET | BPF_X:
+ src = ebpf_to_mips_reg(ctx, insn, src_reg_no_fp);
+ dst = ebpf_to_mips_reg(ctx, insn, dst_reg);
+ if (src < 0 || dst < 0)
+ return -EINVAL;
+ td = get_reg_val_type(ctx, this_idx, insn->dst_reg);
+ ts = get_reg_val_type(ctx, this_idx, insn->src_reg);
+ if (td == REG_32BIT && ts != REG_32BIT) {
+ emit_instr(ctx, sll, MIPS_R_AT, src, 0);
+ src = MIPS_R_AT;
+ } else if (ts == REG_32BIT && td != REG_32BIT) {
+ emit_instr(ctx, sll, MIPS_R_AT, dst, 0);
+ dst = MIPS_R_AT;
+ }
+ if (BPF_OP(insn->code) == BPF_JSET) {
+ emit_instr(ctx, and, MIPS_R_AT, dst, src);
+ cmp_eq = false;
+ dst = MIPS_R_AT;
+ src = MIPS_R_ZERO;
+ } else if (BPF_OP(insn->code) == BPF_JSGT) {
+ emit_instr(ctx, dsubu, MIPS_R_AT, dst, src);
+ if ((insn + 1)->code == (BPF_JMP | BPF_EXIT) && insn->off == 1) {
+ b_off = b_imm(exit_idx, ctx);
+ if (is_bad_offset(b_off))
+ return -E2BIG;
+ emit_instr(ctx, blez, MIPS_R_AT, b_off);
+ emit_instr(ctx, nop);
+ return 2; /* We consumed the exit. */
+ }
+ b_off = b_imm(this_idx + insn->off + 1, ctx);
+ if (is_bad_offset(b_off))
+ return -E2BIG;
+ emit_instr(ctx, bgtz, MIPS_R_AT, b_off);
+ emit_instr(ctx, nop);
+ break;
+ } else if (BPF_OP(insn->code) == BPF_JSGE) {
+ emit_instr(ctx, slt, MIPS_R_AT, dst, src);
+ cmp_eq = true;
+ dst = MIPS_R_AT;
+ src = MIPS_R_ZERO;
+ } else if (BPF_OP(insn->code) == BPF_JGT) {
+ /* dst or src could be AT */
+ emit_instr(ctx, dsubu, MIPS_R_T8, dst, src);
+ emit_instr(ctx, sltu, MIPS_R_AT, dst, src);
+ /* SP known to be non-zero, movz becomes boolean not */
+ emit_instr(ctx, movz, MIPS_R_T9, MIPS_R_SP, MIPS_R_T8);
+ emit_instr(ctx, movn, MIPS_R_T9, MIPS_R_ZERO, MIPS_R_T8);
+ emit_instr(ctx, or, MIPS_R_AT, MIPS_R_T9, MIPS_R_AT);
+ cmp_eq = true;
+ dst = MIPS_R_AT;
+ src = MIPS_R_ZERO;
+ } else if (BPF_OP(insn->code) == BPF_JGE) {
+ emit_instr(ctx, sltu, MIPS_R_AT, dst, src);
+ cmp_eq = true;
+ dst = MIPS_R_AT;
+ src = MIPS_R_ZERO;
+ } else { /* JNE/JEQ case */
+ cmp_eq = (BPF_OP(insn->code) == BPF_JEQ);
+ }
+jeq_common:
+ /*
+ * If the next insn is EXIT and we are jumping arround
+ * only it, invert the sense of the compare and
+ * conditionally jump to the exit. Poor man's branch
+ * chaining.
+ */
+ if ((insn + 1)->code == (BPF_JMP | BPF_EXIT) && insn->off == 1) {
+ b_off = b_imm(exit_idx, ctx);
+ if (is_bad_offset(b_off)) {
+ target = j_target(ctx, exit_idx);
+ if (target == (unsigned int)-1)
+ return -E2BIG;
+ cmp_eq = !cmp_eq;
+ b_off = 4 * 3;
+ if (!(ctx->offsets[this_idx] & OFFSETS_B_CONV)) {
+ ctx->offsets[this_idx] |= OFFSETS_B_CONV;
+ ctx->long_b_conversion = 1;
+ }
+ }
+
+ if (cmp_eq)
+ emit_instr(ctx, bne, dst, src, b_off);
+ else
+ emit_instr(ctx, beq, dst, src, b_off);
+ emit_instr(ctx, nop);
+ if (ctx->offsets[this_idx] & OFFSETS_B_CONV) {
+ emit_instr(ctx, j, target);
+ emit_instr(ctx, nop);
+ }
+ return 2; /* We consumed the exit. */
+ }
+ b_off = b_imm(this_idx + insn->off + 1, ctx);
+ if (is_bad_offset(b_off)) {
+ target = j_target(ctx, this_idx + insn->off + 1);
+ if (target == (unsigned int)-1)
+ return -E2BIG;
+ cmp_eq = !cmp_eq;
+ b_off = 4 * 3;
+ if (!(ctx->offsets[this_idx] & OFFSETS_B_CONV)) {
+ ctx->offsets[this_idx] |= OFFSETS_B_CONV;
+ ctx->long_b_conversion = 1;
+ }
+ }
+
+ if (cmp_eq)
+ emit_instr(ctx, beq, dst, src, b_off);
+ else
+ emit_instr(ctx, bne, dst, src, b_off);
+ emit_instr(ctx, nop);
+ if (ctx->offsets[this_idx] & OFFSETS_B_CONV) {
+ emit_instr(ctx, j, target);
+ emit_instr(ctx, nop);
+ }
+ break;
+ case BPF_JMP | BPF_JSGT | BPF_K: /* JMP_IMM */
+ case BPF_JMP | BPF_JSGE | BPF_K: /* JMP_IMM */
+ cmp_eq = (BPF_OP(insn->code) == BPF_JSGE);
+ dst = ebpf_to_mips_reg(ctx, insn, dst_reg_fp_ok);
+ if (dst < 0)
+ return dst;
+
+ if (insn->imm == 0) {
+ if ((insn + 1)->code == (BPF_JMP | BPF_EXIT) && insn->off == 1) {
+ b_off = b_imm(exit_idx, ctx);
+ if (is_bad_offset(b_off))
+ return -E2BIG;
+ if (cmp_eq)
+ emit_instr(ctx, bltz, dst, b_off);
+ else
+ emit_instr(ctx, blez, dst, b_off);
+ emit_instr(ctx, nop);
+ return 2; /* We consumed the exit. */
+ }
+ b_off = b_imm(this_idx + insn->off + 1, ctx);
+ if (is_bad_offset(b_off))
+ return -E2BIG;
+ if (cmp_eq)
+ emit_instr(ctx, bgez, dst, b_off);
+ else
+ emit_instr(ctx, bgtz, dst, b_off);
+ emit_instr(ctx, nop);
+ break;
+ }
+ /*
+ * only "LT" compare available, so we must use imm + 1
+ * to generate "GT"
+ */
+ t64s = insn->imm + (cmp_eq ? 0 : 1);
+ if (t64s >= S16_MIN && t64s <= S16_MAX) {
+ emit_instr(ctx, slti, MIPS_R_AT, dst, (int)t64s);
+ src = MIPS_R_AT;
+ dst = MIPS_R_ZERO;
+ cmp_eq = true;
+ goto jeq_common;
+ }
+ emit_const_to_reg(ctx, MIPS_R_AT, (u64)t64s);
+ emit_instr(ctx, slt, MIPS_R_AT, dst, MIPS_R_AT);
+ src = MIPS_R_AT;
+ dst = MIPS_R_ZERO;
+ cmp_eq = true;
+ goto jeq_common;
+
+ case BPF_JMP | BPF_JGT | BPF_K:
+ case BPF_JMP | BPF_JGE | BPF_K:
+ cmp_eq = (BPF_OP(insn->code) == BPF_JGE);
+ dst = ebpf_to_mips_reg(ctx, insn, dst_reg_fp_ok);
+ if (dst < 0)
+ return dst;
+ /*
+ * only "LT" compare available, so we must use imm + 1
+ * to generate "GT"
+ */
+ t64s = (u64)(u32)(insn->imm) + (cmp_eq ? 0 : 1);
+ if (t64s >= 0 && t64s <= S16_MAX) {
+ emit_instr(ctx, sltiu, MIPS_R_AT, dst, (int)t64s);
+ src = MIPS_R_AT;
+ dst = MIPS_R_ZERO;
+ cmp_eq = true;
+ goto jeq_common;
+ }
+ emit_const_to_reg(ctx, MIPS_R_AT, (u64)t64s);
+ emit_instr(ctx, sltu, MIPS_R_AT, dst, MIPS_R_AT);
+ src = MIPS_R_AT;
+ dst = MIPS_R_ZERO;
+ cmp_eq = true;
+ goto jeq_common;
+
+ case BPF_JMP | BPF_JSET | BPF_K: /* JMP_IMM */
+ dst = ebpf_to_mips_reg(ctx, insn, dst_reg_fp_ok);
+ if (dst < 0)
+ return dst;
+
+ if (use_bbit_insns() && hweight32((u32)insn->imm) == 1) {
+ if ((insn + 1)->code == (BPF_JMP | BPF_EXIT) && insn->off == 1) {
+ b_off = b_imm(exit_idx, ctx);
+ if (is_bad_offset(b_off))
+ return -E2BIG;
+ emit_instr(ctx, bbit0, dst, ffs((u32)insn->imm) - 1, b_off);
+ emit_instr(ctx, nop);
+ return 2; /* We consumed the exit. */
+ }
+ b_off = b_imm(this_idx + insn->off + 1, ctx);
+ if (is_bad_offset(b_off))
+ return -E2BIG;
+ emit_instr(ctx, bbit1, dst, ffs((u32)insn->imm) - 1, b_off);
+ emit_instr(ctx, nop);
+ break;
+ }
+ t64 = (u32)insn->imm;
+ emit_const_to_reg(ctx, MIPS_R_AT, t64);
+ emit_instr(ctx, and, MIPS_R_AT, dst, MIPS_R_AT);
+ src = MIPS_R_AT;
+ dst = MIPS_R_ZERO;
+ cmp_eq = false;
+ goto jeq_common;
+
+ case BPF_JMP | BPF_JA:
+ /*
+ * Prefer relative branch for easier debugging, but
+ * fall back if needed.
+ */
+ b_off = b_imm(this_idx + insn->off + 1, ctx);
+ if (is_bad_offset(b_off)) {
+ target = j_target(ctx, this_idx + insn->off + 1);
+ if (target == (unsigned int)-1)
+ return -E2BIG;
+ emit_instr(ctx, j, target);
+ } else {
+ emit_instr(ctx, b, b_off);
+ }
+ emit_instr(ctx, nop);
+ break;
+ case BPF_LD | BPF_DW | BPF_IMM:
+ if (insn->src_reg != 0)
+ return -EINVAL;
+ dst = ebpf_to_mips_reg(ctx, insn, dst_reg);
+ if (dst < 0)
+ return dst;
+ t64 = ((u64)(u32)insn->imm) | ((u64)(insn + 1)->imm << 32);
+ emit_const_to_reg(ctx, dst, t64);
+ return 2; /* Double slot insn */
+
+ case BPF_JMP | BPF_CALL:
+ ctx->flags |= EBPF_SAVE_RA;
+ t64s = (s64)insn->imm + (s64)__bpf_call_base;
+ emit_const_to_reg(ctx, MIPS_R_T9, (u64)t64s);
+ emit_instr(ctx, jalr, MIPS_R_RA, MIPS_R_T9);
+ /* delay slot */
+ emit_instr(ctx, nop);
+ break;
+
+ case BPF_JMP | BPF_TAIL_CALL:
+ if (emit_bpf_tail_call(ctx, this_idx))
+ return -EINVAL;
+ break;
+
+ case BPF_LD | BPF_B | BPF_ABS:
+ case BPF_LD | BPF_H | BPF_ABS:
+ case BPF_LD | BPF_W | BPF_ABS:
+ case BPF_LD | BPF_DW | BPF_ABS:
+ ctx->flags |= EBPF_SAVE_RA;
+
+ gen_imm_to_reg(insn, MIPS_R_A1, ctx);
+ emit_instr(ctx, addiu, MIPS_R_A2, MIPS_R_ZERO, size_to_len(insn));
+
+ if (insn->imm < 0) {
+ emit_const_to_reg(ctx, MIPS_R_T9, (u64)bpf_internal_load_pointer_neg_helper);
+ } else {
+ emit_const_to_reg(ctx, MIPS_R_T9, (u64)ool_skb_header_pointer);
+ emit_instr(ctx, daddiu, MIPS_R_A3, MIPS_R_SP, ctx->tmp_offset);
+ }
+ goto ld_skb_common;
+
+ case BPF_LD | BPF_B | BPF_IND:
+ case BPF_LD | BPF_H | BPF_IND:
+ case BPF_LD | BPF_W | BPF_IND:
+ case BPF_LD | BPF_DW | BPF_IND:
+ ctx->flags |= EBPF_SAVE_RA;
+ src = ebpf_to_mips_reg(ctx, insn, src_reg_no_fp);
+ if (src < 0)
+ return src;
+ ts = get_reg_val_type(ctx, this_idx, insn->src_reg);
+ if (ts == REG_32BIT_ZERO_EX) {
+ /* sign extend */
+ emit_instr(ctx, sll, MIPS_R_A1, src, 0);
+ src = MIPS_R_A1;
+ }
+ if (insn->imm >= S16_MIN && insn->imm <= S16_MAX) {
+ emit_instr(ctx, daddiu, MIPS_R_A1, src, insn->imm);
+ } else {
+ gen_imm_to_reg(insn, MIPS_R_AT, ctx);
+ emit_instr(ctx, daddu, MIPS_R_A1, MIPS_R_AT, src);
+ }
+ /* truncate to 32-bit int */
+ emit_instr(ctx, sll, MIPS_R_A1, MIPS_R_A1, 0);
+ emit_instr(ctx, daddiu, MIPS_R_A3, MIPS_R_SP, ctx->tmp_offset);
+ emit_instr(ctx, slt, MIPS_R_AT, MIPS_R_A1, MIPS_R_ZERO);
+
+ emit_const_to_reg(ctx, MIPS_R_T8, (u64)bpf_internal_load_pointer_neg_helper);
+ emit_const_to_reg(ctx, MIPS_R_T9, (u64)ool_skb_header_pointer);
+ emit_instr(ctx, addiu, MIPS_R_A2, MIPS_R_ZERO, size_to_len(insn));
+ emit_instr(ctx, movn, MIPS_R_T9, MIPS_R_T8, MIPS_R_AT);
+
+ld_skb_common:
+ emit_instr(ctx, jalr, MIPS_R_RA, MIPS_R_T9);
+ /* delay slot move */
+ emit_instr(ctx, daddu, MIPS_R_A0, MIPS_R_S0, MIPS_R_ZERO);
+
+ /* Check the error value */
+ b_off = b_imm(exit_idx, ctx);
+ if (is_bad_offset(b_off)) {
+ target = j_target(ctx, exit_idx);
+ if (target == (unsigned int)-1)
+ return -E2BIG;
+
+ if (!(ctx->offsets[this_idx] & OFFSETS_B_CONV)) {
+ ctx->offsets[this_idx] |= OFFSETS_B_CONV;
+ ctx->long_b_conversion = 1;
+ }
+ emit_instr(ctx, bne, MIPS_R_V0, MIPS_R_ZERO, 4 * 3);
+ emit_instr(ctx, nop);
+ emit_instr(ctx, j, target);
+ emit_instr(ctx, nop);
+ } else {
+ emit_instr(ctx, beq, MIPS_R_V0, MIPS_R_ZERO, b_off);
+ emit_instr(ctx, nop);
+ }
+
+#ifdef __BIG_ENDIAN
+ need_swap = false;
+#else
+ need_swap = true;
+#endif
+ dst = MIPS_R_V0;
+ switch (BPF_SIZE(insn->code)) {
+ case BPF_B:
+ emit_instr(ctx, lbu, dst, 0, MIPS_R_V0);
+ break;
+ case BPF_H:
+ emit_instr(ctx, lhu, dst, 0, MIPS_R_V0);
+ if (need_swap)
+ emit_instr(ctx, wsbh, dst, dst);
+ break;
+ case BPF_W:
+ emit_instr(ctx, lw, dst, 0, MIPS_R_V0);
+ if (need_swap) {
+ emit_instr(ctx, wsbh, dst, dst);
+ emit_instr(ctx, rotr, dst, dst, 16);
+ }
+ break;
+ case BPF_DW:
+ emit_instr(ctx, ld, dst, 0, MIPS_R_V0);
+ if (need_swap) {
+ emit_instr(ctx, dsbh, dst, dst);
+ emit_instr(ctx, dshd, dst, dst);
+ }
+ break;
+ }
+
+ break;
+ case BPF_ALU | BPF_END | BPF_FROM_BE:
+ case BPF_ALU | BPF_END | BPF_FROM_LE:
+ dst = ebpf_to_mips_reg(ctx, insn, dst_reg);
+ if (dst < 0)
+ return dst;
+ td = get_reg_val_type(ctx, this_idx, insn->dst_reg);
+ if (insn->imm == 64 && td == REG_32BIT)
+ emit_instr(ctx, dinsu, dst, MIPS_R_ZERO, 32, 32);
+
+ if (insn->imm != 64 &&
+ (td == REG_64BIT || td == REG_32BIT_ZERO_EX)) {
+ /* sign extend */
+ emit_instr(ctx, sll, dst, dst, 0);
+ }
+
+#ifdef __BIG_ENDIAN
+ need_swap = (BPF_SRC(insn->code) == BPF_FROM_LE);
+#else
+ need_swap = (BPF_SRC(insn->code) == BPF_FROM_BE);
+#endif
+ if (insn->imm == 16) {
+ if (need_swap)
+ emit_instr(ctx, wsbh, dst, dst);
+ emit_instr(ctx, andi, dst, dst, 0xffff);
+ } else if (insn->imm == 32) {
+ if (need_swap) {
+ emit_instr(ctx, wsbh, dst, dst);
+ emit_instr(ctx, rotr, dst, dst, 16);
+ }
+ } else { /* 64-bit*/
+ if (need_swap) {
+ emit_instr(ctx, dsbh, dst, dst);
+ emit_instr(ctx, dshd, dst, dst);
+ }
+ }
+ break;
+
+ case BPF_ST | BPF_B | BPF_MEM:
+ case BPF_ST | BPF_H | BPF_MEM:
+ case BPF_ST | BPF_W | BPF_MEM:
+ case BPF_ST | BPF_DW | BPF_MEM:
+ if (insn->dst_reg == BPF_REG_10) {
+ ctx->flags |= EBPF_SEEN_FP;
+ dst = MIPS_R_SP;
+ mem_off = insn->off + MAX_BPF_STACK;
+ } else {
+ dst = ebpf_to_mips_reg(ctx, insn, dst_reg);
+ if (dst < 0)
+ return dst;
+ mem_off = insn->off;
+ }
+ gen_imm_to_reg(insn, MIPS_R_AT, ctx);
+ switch (BPF_SIZE(insn->code)) {
+ case BPF_B:
+ emit_instr(ctx, sb, MIPS_R_AT, mem_off, dst);
+ break;
+ case BPF_H:
+ emit_instr(ctx, sh, MIPS_R_AT, mem_off, dst);
+ break;
+ case BPF_W:
+ emit_instr(ctx, sw, MIPS_R_AT, mem_off, dst);
+ break;
+ case BPF_DW:
+ emit_instr(ctx, sd, MIPS_R_AT, mem_off, dst);
+ break;
+ }
+ break;
+
+ case BPF_LDX | BPF_B | BPF_MEM:
+ case BPF_LDX | BPF_H | BPF_MEM:
+ case BPF_LDX | BPF_W | BPF_MEM:
+ case BPF_LDX | BPF_DW | BPF_MEM:
+ if (insn->src_reg == BPF_REG_10) {
+ ctx->flags |= EBPF_SEEN_FP;
+ src = MIPS_R_SP;
+ mem_off = insn->off + MAX_BPF_STACK;
+ } else {
+ src = ebpf_to_mips_reg(ctx, insn, src_reg_no_fp);
+ if (src < 0)
+ return src;
+ mem_off = insn->off;
+ }
+ dst = ebpf_to_mips_reg(ctx, insn, dst_reg);
+ if (dst < 0)
+ return dst;
+ switch (BPF_SIZE(insn->code)) {
+ case BPF_B:
+ emit_instr(ctx, lbu, dst, mem_off, src);
+ break;
+ case BPF_H:
+ emit_instr(ctx, lhu, dst, mem_off, src);
+ break;
+ case BPF_W:
+ emit_instr(ctx, lw, dst, mem_off, src);
+ break;
+ case BPF_DW:
+ emit_instr(ctx, ld, dst, mem_off, src);
+ break;
+ }
+ break;
+
+ case BPF_STX | BPF_B | BPF_MEM:
+ case BPF_STX | BPF_H | BPF_MEM:
+ case BPF_STX | BPF_W | BPF_MEM:
+ case BPF_STX | BPF_DW | BPF_MEM:
+ case BPF_STX | BPF_W | BPF_XADD:
+ case BPF_STX | BPF_DW | BPF_XADD:
+ if (insn->dst_reg == BPF_REG_10) {
+ ctx->flags |= EBPF_SEEN_FP;
+ dst = MIPS_R_SP;
+ mem_off = insn->off + MAX_BPF_STACK;
+ } else {
+ dst = ebpf_to_mips_reg(ctx, insn, dst_reg);
+ if (dst < 0)
+ return dst;
+ mem_off = insn->off;
+ }
+ src = ebpf_to_mips_reg(ctx, insn, src_reg_no_fp);
+ if (src < 0)
+ return dst;
+ if (BPF_MODE(insn->code) == BPF_XADD) {
+ switch (BPF_SIZE(insn->code)) {
+ case BPF_W:
+ if (get_reg_val_type(ctx, this_idx, insn->src_reg) == REG_32BIT) {
+ emit_instr(ctx, sll, MIPS_R_AT, src, 0);
+ src = MIPS_R_AT;
+ }
+ emit_instr(ctx, ll, MIPS_R_T8, mem_off, dst);
+ emit_instr(ctx, addu, MIPS_R_T8, MIPS_R_T8, src);
+ emit_instr(ctx, sc, MIPS_R_T8, mem_off, dst);
+ /*
+ * On failure back up to LL (-4
+ * instructions of 4 bytes each
+ */
+ emit_instr(ctx, beq, MIPS_R_T8, MIPS_R_ZERO, -4 * 4);
+ emit_instr(ctx, nop);
+ break;
+ case BPF_DW:
+ if (get_reg_val_type(ctx, this_idx, insn->src_reg) == REG_32BIT) {
+ emit_instr(ctx, daddu, MIPS_R_AT, src, MIPS_R_ZERO);
+ emit_instr(ctx, dinsu, MIPS_R_AT, MIPS_R_ZERO, 32, 32);
+ src = MIPS_R_AT;
+ }
+ emit_instr(ctx, lld, MIPS_R_T8, mem_off, dst);
+ emit_instr(ctx, daddu, MIPS_R_T8, MIPS_R_T8, src);
+ emit_instr(ctx, scd, MIPS_R_T8, mem_off, dst);
+ emit_instr(ctx, beq, MIPS_R_T8, MIPS_R_ZERO, -4 * 4);
+ emit_instr(ctx, nop);
+ break;
+ }
+ } else { /* BPF_MEM */
+ switch (BPF_SIZE(insn->code)) {
+ case BPF_B:
+ emit_instr(ctx, sb, src, mem_off, dst);
+ break;
+ case BPF_H:
+ emit_instr(ctx, sh, src, mem_off, dst);
+ break;
+ case BPF_W:
+ emit_instr(ctx, sw, src, mem_off, dst);
+ break;
+ case BPF_DW:
+ if (get_reg_val_type(ctx, this_idx, insn->src_reg) == REG_32BIT) {
+ emit_instr(ctx, daddu, MIPS_R_AT, src, MIPS_R_ZERO);
+ emit_instr(ctx, dinsu, MIPS_R_AT, MIPS_R_ZERO, 32, 32);
+ src = MIPS_R_AT;
+ }
+ emit_instr(ctx, sd, src, mem_off, dst);
+ break;
+ }
+ }
+ break;
+
+ default:
+ pr_err("NOT HANDLED %d - (%02x)\n",
+ this_idx, (unsigned int)insn->code);
+ return -EINVAL;
+ }
+ return 1;
+}
+
+#define RVT_VISITED_MASK 0xc000000000000000ull
+#define RVT_FALL_THROUGH 0x4000000000000000ull
+#define RVT_BRANCH_TAKEN 0x8000000000000000ull
+#define RVT_DONE (RVT_FALL_THROUGH | RVT_BRANCH_TAKEN)
+
+static int build_int_body(struct jit_ctx *ctx)
+{
+ const struct bpf_prog *prog = ctx->skf;
+ const struct bpf_insn *insn;
+ int i, r;
+
+ for (i = 0; i < prog->len; ) {
+ insn = prog->insnsi + i;
+ if ((ctx->reg_val_types[i] & RVT_VISITED_MASK) == 0) {
+ /* dead instruction, don't emit it. */
+ i++;
+ continue;
+ }
+
+ if (ctx->target == NULL)
+ ctx->offsets[i] = (ctx->offsets[i] & OFFSETS_B_CONV) | (ctx->idx * 4);
+
+ r = build_one_insn(insn, ctx, i, prog->len);
+ if (r < 0)
+ return r;
+ i += r;
+ }
+ /* epilogue offset */
+ if (ctx->target == NULL)
+ ctx->offsets[i] = ctx->idx * 4;
+
+ /*
+ * All exits have an offset of the epilogue, some offsets may
+ * not have been set due to banch-around threading, so set
+ * them now.
+ */
+ if (ctx->target == NULL)
+ for (i = 0; i < prog->len; i++) {
+ insn = prog->insnsi + i;
+ if (insn->code == (BPF_JMP | BPF_EXIT))
+ ctx->offsets[i] = ctx->idx * 4;
+ }
+ return 0;
+}
+
+/* return the last idx processed, or negative for error */
+static int reg_val_propagate_range(struct jit_ctx *ctx, u64 initial_rvt,
+ int start_idx, bool follow_taken)
+{
+ const struct bpf_prog *prog = ctx->skf;
+ const struct bpf_insn *insn;
+ u64 exit_rvt = initial_rvt;
+ u64 *rvt = ctx->reg_val_types;
+ int idx;
+ int reg;
+
+ for (idx = start_idx; idx < prog->len; idx++) {
+ rvt[idx] = (rvt[idx] & RVT_VISITED_MASK) | exit_rvt;
+ insn = prog->insnsi + idx;
+ switch (BPF_CLASS(insn->code)) {
+ case BPF_ALU:
+ switch (BPF_OP(insn->code)) {
+ case BPF_ADD:
+ case BPF_SUB:
+ case BPF_MUL:
+ case BPF_DIV:
+ case BPF_OR:
+ case BPF_AND:
+ case BPF_LSH:
+ case BPF_RSH:
+ case BPF_NEG:
+ case BPF_MOD:
+ case BPF_XOR:
+ set_reg_val_type(&exit_rvt, insn->dst_reg, REG_32BIT);
+ break;
+ case BPF_MOV:
+ if (BPF_SRC(insn->code)) {
+ set_reg_val_type(&exit_rvt, insn->dst_reg, REG_32BIT);
+ } else {
+ /* IMM to REG move*/
+ if (insn->imm >= 0)
+ set_reg_val_type(&exit_rvt, insn->dst_reg, REG_32BIT_POS);
+ else
+ set_reg_val_type(&exit_rvt, insn->dst_reg, REG_32BIT);
+ }
+ break;
+ case BPF_END:
+ if (insn->imm == 64)
+ set_reg_val_type(&exit_rvt, insn->dst_reg, REG_64BIT);
+ else if (insn->imm == 32)
+ set_reg_val_type(&exit_rvt, insn->dst_reg, REG_32BIT);
+ else /* insn->imm == 16 */
+ set_reg_val_type(&exit_rvt, insn->dst_reg, REG_32BIT_POS);
+ break;
+ }
+ rvt[idx] |= RVT_DONE;
+ break;
+ case BPF_ALU64:
+ switch (BPF_OP(insn->code)) {
+ case BPF_MOV:
+ if (BPF_SRC(insn->code)) {
+ /* REG to REG move*/
+ set_reg_val_type(&exit_rvt, insn->dst_reg, REG_64BIT);
+ } else {
+ /* IMM to REG move*/
+ if (insn->imm >= 0)
+ set_reg_val_type(&exit_rvt, insn->dst_reg, REG_32BIT_POS);
+ else
+ set_reg_val_type(&exit_rvt, insn->dst_reg, REG_64BIT_32BIT);
+ }
+ break;
+ default:
+ set_reg_val_type(&exit_rvt, insn->dst_reg, REG_64BIT);
+ }
+ rvt[idx] |= RVT_DONE;
+ break;
+ case BPF_LD:
+ switch (BPF_SIZE(insn->code)) {
+ case BPF_DW:
+ if (BPF_MODE(insn->code) == BPF_IMM) {
+ s64 val;
+
+ val = (s64)((u32)insn->imm | ((u64)(insn + 1)->imm << 32));
+ if (val > 0 && val <= S32_MAX)
+ set_reg_val_type(&exit_rvt, insn->dst_reg, REG_32BIT_POS);
+ else if (val >= S32_MIN && val <= S32_MAX)
+ set_reg_val_type(&exit_rvt, insn->dst_reg, REG_64BIT_32BIT);
+ else
+ set_reg_val_type(&exit_rvt, insn->dst_reg, REG_64BIT);
+ rvt[idx] |= RVT_DONE;
+ idx++;
+ } else {
+ set_reg_val_type(&exit_rvt, insn->dst_reg, REG_64BIT);
+ }
+ break;
+ case BPF_B:
+ case BPF_H:
+ set_reg_val_type(&exit_rvt, insn->dst_reg, REG_32BIT_POS);
+ break;
+ case BPF_W:
+ if (BPF_MODE(insn->code) == BPF_IMM)
+ set_reg_val_type(&exit_rvt, insn->dst_reg,
+ insn->imm >= 0 ? REG_32BIT_POS : REG_32BIT);
+ else
+ set_reg_val_type(&exit_rvt, insn->dst_reg, REG_32BIT);
+ break;
+ }
+ rvt[idx] |= RVT_DONE;
+ break;
+ case BPF_LDX:
+ switch (BPF_SIZE(insn->code)) {
+ case BPF_DW:
+ set_reg_val_type(&exit_rvt, insn->dst_reg, REG_64BIT);
+ break;
+ case BPF_B:
+ case BPF_H:
+ set_reg_val_type(&exit_rvt, insn->dst_reg, REG_32BIT_POS);
+ break;
+ case BPF_W:
+ set_reg_val_type(&exit_rvt, insn->dst_reg, REG_32BIT);
+ break;
+ }
+ rvt[idx] |= RVT_DONE;
+ break;
+ case BPF_JMP:
+ switch (BPF_OP(insn->code)) {
+ case BPF_EXIT:
+ rvt[idx] = RVT_DONE | exit_rvt;
+ rvt[prog->len] = exit_rvt;
+ return idx;
+ case BPF_JA:
+ rvt[idx] |= RVT_DONE;
+ idx += insn->off;
+ break;
+ case BPF_JEQ:
+ case BPF_JGT:
+ case BPF_JGE:
+ case BPF_JSET:
+ case BPF_JNE:
+ case BPF_JSGT:
+ case BPF_JSGE:
+ if (follow_taken) {
+ rvt[idx] |= RVT_BRANCH_TAKEN;
+ idx += insn->off;
+ follow_taken = false;
+ } else {
+ rvt[idx] |= RVT_FALL_THROUGH;
+ }
+ break;
+ case BPF_CALL:
+ set_reg_val_type(&exit_rvt, BPF_REG_0, REG_64BIT);
+ /* Upon call return, argument registers are clobbered. */
+ for (reg = BPF_REG_0; reg <= BPF_REG_5; reg++)
+ set_reg_val_type(&exit_rvt, reg, REG_64BIT);
+
+ rvt[idx] |= RVT_DONE;
+ break;
+ default:
+ WARN(1, "Unhandled BPF_JMP case.\n");
+ rvt[idx] |= RVT_DONE;
+ break;
+ }
+ break;
+ default:
+ rvt[idx] |= RVT_DONE;
+ break;
+ }
+ }
+ return idx;
+}
+
+/*
+ * Track the value range (i.e. 32-bit vs. 64-bit) of each register at
+ * each eBPF insn. This allows unneeded sign and zero extension
+ * operations to be omitted.
+ *
+ * Doesn't handle yet confluence of control paths with conflicting
+ * ranges, but it is good enough for most sane code.
+ */
+static int reg_val_propagate(struct jit_ctx *ctx)
+{
+ const struct bpf_prog *prog = ctx->skf;
+ u64 exit_rvt;
+ int reg;
+ int i;
+
+ /*
+ * 11 registers * 3 bits/reg leaves top bits free for other
+ * uses. Bit-62..63 used to see if we have visited an insn.
+ */
+ exit_rvt = 0;
+
+ /* Upon entry, argument registers are 64-bit. */
+ for (reg = BPF_REG_1; reg <= BPF_REG_5; reg++)
+ set_reg_val_type(&exit_rvt, reg, REG_64BIT);
+
+ /*
+ * First follow all conditional branches on the fall-through
+ * edge of control flow..
+ */
+ reg_val_propagate_range(ctx, exit_rvt, 0, false);
+restart_search:
+ /*
+ * Then repeatedly find the first conditional branch where
+ * both edges of control flow have not been taken, and follow
+ * the branch taken edge. We will end up restarting the
+ * search once per conditional branch insn.
+ */
+ for (i = 0; i < prog->len; i++) {
+ u64 rvt = ctx->reg_val_types[i];
+
+ if ((rvt & RVT_VISITED_MASK) == RVT_DONE ||
+ (rvt & RVT_VISITED_MASK) == 0)
+ continue;
+ if ((rvt & RVT_VISITED_MASK) == RVT_FALL_THROUGH) {
+ reg_val_propagate_range(ctx, rvt & ~RVT_VISITED_MASK, i, true);
+ } else { /* RVT_BRANCH_TAKEN */
+ WARN(1, "Unexpected RVT_BRANCH_TAKEN case.\n");
+ reg_val_propagate_range(ctx, rvt & ~RVT_VISITED_MASK, i, false);
+ }
+ goto restart_search;
+ }
+ /*
+ * Eventually all conditional branches have been followed on
+ * both branches and we are done. Any insn that has not been
+ * visited at this point is dead.
+ */
+
+ return 0;
+}
+
+static void jit_fill_hole(void *area, unsigned int size)
+{
+ u32 *p;
+
+ /* We are guaranteed to have aligned memory. */
+ for (p = area; size >= sizeof(u32); size -= sizeof(u32))
+ uasm_i_break(&p, BRK_BUG); /* Increments p */
+}
+
+struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
+{
+ struct bpf_prog *orig_prog = prog;
+ bool tmp_blinded = false;
+ struct bpf_prog *tmp;
+ struct bpf_binary_header *header = NULL;
+ struct jit_ctx ctx;
+ unsigned int image_size;
+ u8 *image_ptr;
+
+ if (!bpf_jit_enable || !cpu_has_mips64r2)
+ return prog;
+
+ tmp = bpf_jit_blind_constants(prog);
+ /* If blinding was requested and we failed during blinding,
+ * we must fall back to the interpreter.
+ */
+ if (IS_ERR(tmp))
+ return orig_prog;
+ if (tmp != prog) {
+ tmp_blinded = true;
+ prog = tmp;
+ }
+
+ memset(&ctx, 0, sizeof(ctx));
+
+ ctx.offsets = kcalloc(prog->len + 1, sizeof(*ctx.offsets), GFP_KERNEL);
+ if (ctx.offsets == NULL)
+ goto out_err;
+
+ ctx.reg_val_types = kcalloc(prog->len + 1, sizeof(*ctx.reg_val_types), GFP_KERNEL);
+ if (ctx.reg_val_types == NULL)
+ goto out_err;
+
+ ctx.skf = prog;
+
+ if (reg_val_propagate(&ctx))
+ goto out_err;
+
+ /*
+ * First pass discovers used resources and instruction offsets
+ * assuming short branches are used.
+ */
+ if (build_int_body(&ctx))
+ goto out_err;
+
+ /*
+ * If no calls are made (EBPF_SAVE_RA), then tail call count
+ * in $v1, else we must save in n$s4.
+ */
+ if (ctx.flags & EBPF_SEEN_TC) {
+ if (ctx.flags & EBPF_SAVE_RA)
+ ctx.flags |= EBPF_SAVE_S4;
+ else
+ ctx.flags |= EBPF_TCC_IN_V1;
+ }
+
+ /*
+ * Second pass generates offsets, if any branches are out of
+ * range a jump-around long sequence is generated, and we have
+ * to try again from the beginning to generate the new
+ * offsets. This is done until no additional conversions are
+ * necessary.
+ */
+ do {
+ ctx.idx = 0;
+ ctx.gen_b_offsets = 1;
+ ctx.long_b_conversion = 0;
+ if (gen_int_prologue(&ctx))
+ goto out_err;
+ if (build_int_body(&ctx))
+ goto out_err;
+ if (build_int_epilogue(&ctx, MIPS_R_RA))
+ goto out_err;
+ } while (ctx.long_b_conversion);
+
+ image_size = 4 * ctx.idx;
+
+ header = bpf_jit_binary_alloc(image_size, &image_ptr,
+ sizeof(u32), jit_fill_hole);
+ if (header == NULL)
+ goto out_err;
+
+ ctx.target = (u32 *)image_ptr;
+
+ /* Third pass generates the code */
+ ctx.idx = 0;
+ if (gen_int_prologue(&ctx))
+ goto out_err;
+ if (build_int_body(&ctx))
+ goto out_err;
+ if (build_int_epilogue(&ctx, MIPS_R_RA))
+ goto out_err;
+
+ /* Update the icache */
+ flush_icache_range((unsigned long)ctx.target,
+ (unsigned long)(ctx.target + ctx.idx * sizeof(u32)));
+
+ if (bpf_jit_enable > 1)
+ /* Dump JIT code */
+ bpf_jit_dump(prog->len, image_size, 2, ctx.target);
+
+ bpf_jit_binary_lock_ro(header);
+ prog->bpf_func = (void *)ctx.target;
+ prog->jited = 1;
+ prog->jited_len = image_size;
+out_normal:
+ if (tmp_blinded)
+ bpf_jit_prog_release_other(prog, prog == orig_prog ?
+ tmp : orig_prog);
+ kfree(ctx.offsets);
+ kfree(ctx.reg_val_types);
+
+ return prog;
+
+out_err:
+ prog = orig_prog;
+ if (header)
+ bpf_jit_binary_free(header);
+ goto out_normal;
+}
projects / mirror_ubuntu-eoan-kernel.git / commitdiff