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9a038e7fd1
Copy config and patches from kernel 5.10 to kernel 5.15 Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
3079 lines
89 KiB
Diff
3079 lines
89 KiB
Diff
From: Johan Almbladh <johan.almbladh@anyfinetworks.com>
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Date: Tue, 5 Oct 2021 18:54:04 +0200
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Subject: [PATCH] mips: bpf: Add eBPF JIT for 32-bit MIPS
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This is an implementation of an eBPF JIT for 32-bit MIPS I-V and MIPS32.
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The implementation supports all 32-bit and 64-bit ALU and JMP operations,
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including the recently-added atomics. 64-bit div/mod and 64-bit atomics
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are implemented using function calls to math64 and atomic64 functions,
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respectively. All 32-bit operations are implemented natively by the JIT,
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except if the CPU lacks ll/sc instructions.
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Register mapping
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================
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All 64-bit eBPF registers are mapped to native 32-bit MIPS register pairs,
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and does not use any stack scratch space for register swapping. This means
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that all eBPF register data is kept in CPU registers all the time, and
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this simplifies the register management a lot. It also reduces the JIT's
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pressure on temporary registers since we do not have to move data around.
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Native register pairs are ordered according to CPU endiannes, following
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the O32 calling convention for passing 64-bit arguments and return values.
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The eBPF return value, arguments and callee-saved registers are mapped to
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their native MIPS equivalents.
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Since the 32 highest bits in the eBPF FP (frame pointer) register are
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always zero, only one general-purpose register is actually needed for the
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mapping. The MIPS fp register is used for this purpose. The high bits are
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mapped to MIPS register r0. This saves us one CPU register, which is much
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needed for temporaries, while still allowing us to treat the R10 (FP)
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register just like any other eBPF register in the JIT.
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The MIPS gp (global pointer) and at (assembler temporary) registers are
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used as internal temporary registers for constant blinding. CPU registers
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t6-t9 are used internally by the JIT when constructing more complex 64-bit
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operations. This is precisely what is needed - two registers to store an
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operand value, and two more as scratch registers when performing the
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operation.
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The register mapping is shown below.
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R0 - $v1, $v0 return value
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R1 - $a1, $a0 argument 1, passed in registers
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R2 - $a3, $a2 argument 2, passed in registers
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R3 - $t1, $t0 argument 3, passed on stack
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R4 - $t3, $t2 argument 4, passed on stack
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R5 - $t4, $t3 argument 5, passed on stack
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R6 - $s1, $s0 callee-saved
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R7 - $s3, $s2 callee-saved
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R8 - $s5, $s4 callee-saved
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R9 - $s7, $s6 callee-saved
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FP - $r0, $fp 32-bit frame pointer
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AX - $gp, $at constant-blinding
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$t6 - $t9 unallocated, JIT temporaries
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Jump offsets
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============
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The JIT tries to map all conditional JMP operations to MIPS conditional
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PC-relative branches. The MIPS branch offset field is 18 bits, in bytes,
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which is equivalent to the eBPF 16-bit instruction offset. However, since
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the JIT may emit more than one CPU instruction per eBPF instruction, the
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field width may overflow. If that happens, the JIT converts the long
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conditional jump to a short PC-relative branch with the condition
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inverted, jumping over a long unconditional absolute jmp (j).
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This conversion will change the instruction offset mapping used for jumps,
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and may in turn result in more branch offset overflows. The JIT therefore
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dry-runs the translation until no more branches are converted and the
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offsets do not change anymore. There is an upper bound on this of course,
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and if the JIT hits that limit, the last two iterations are run with all
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branches being converted.
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Tail call count
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===============
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The current tail call count is stored in the 16-byte area of the caller's
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stack frame that is reserved for the callee in the o32 ABI. The value is
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initialized in the prologue, and propagated to the tail-callee by skipping
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the initialization instructions when emitting the tail call.
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Signed-off-by: Johan Almbladh <johan.almbladh@anyfinetworks.com>
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---
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create mode 100644 arch/mips/net/bpf_jit_comp.c
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create mode 100644 arch/mips/net/bpf_jit_comp.h
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create mode 100644 arch/mips/net/bpf_jit_comp32.c
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--- a/arch/mips/net/Makefile
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+++ b/arch/mips/net/Makefile
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@@ -2,4 +2,9 @@
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# MIPS networking code
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obj-$(CONFIG_MIPS_CBPF_JIT) += bpf_jit.o bpf_jit_asm.o
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-obj-$(CONFIG_MIPS_EBPF_JIT) += ebpf_jit.o
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+
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+ifeq ($(CONFIG_32BIT),y)
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+ obj-$(CONFIG_MIPS_EBPF_JIT) += bpf_jit_comp.o bpf_jit_comp32.o
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+else
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+ obj-$(CONFIG_MIPS_EBPF_JIT) += ebpf_jit.o
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+endif
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--- /dev/null
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+++ b/arch/mips/net/bpf_jit_comp.c
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@@ -0,0 +1,1020 @@
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+// SPDX-License-Identifier: GPL-2.0-only
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+/*
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+ * Just-In-Time compiler for eBPF bytecode on MIPS.
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+ * Implementation of JIT functions common to 32-bit and 64-bit CPUs.
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+ *
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+ * Copyright (c) 2021 Anyfi Networks AB.
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+ * Author: Johan Almbladh <johan.almbladh@gmail.com>
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+ *
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+ * Based on code and ideas from
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+ * Copyright (c) 2017 Cavium, Inc.
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+ * Copyright (c) 2017 Shubham Bansal <illusionist.neo@gmail.com>
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+ * Copyright (c) 2011 Mircea Gherzan <mgherzan@gmail.com>
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+ */
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+
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+/*
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+ * Code overview
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+ * =============
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+ *
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+ * - bpf_jit_comp.h
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+ * Common definitions and utilities.
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+ *
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+ * - bpf_jit_comp.c
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+ * Implementation of JIT top-level logic and exported JIT API functions.
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+ * Implementation of internal operations shared by 32-bit and 64-bit code.
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+ * JMP and ALU JIT control code, register control code, shared ALU and
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+ * JMP/JMP32 JIT operations.
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+ *
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+ * - bpf_jit_comp32.c
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+ * Implementation of functions to JIT prologue, epilogue and a single eBPF
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+ * instruction for 32-bit MIPS CPUs. The functions use shared operations
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+ * where possible, and implement the rest for 32-bit MIPS such as ALU64
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+ * operations.
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+ *
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+ * - bpf_jit_comp64.c
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+ * Ditto, for 64-bit MIPS CPUs.
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+ *
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+ * Zero and sign extension
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+ * ========================
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+ * 32-bit MIPS instructions on 64-bit MIPS registers use sign extension,
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+ * but the eBPF instruction set mandates zero extension. We let the verifier
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+ * insert explicit zero-extensions after 32-bit ALU operations, both for
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+ * 32-bit and 64-bit MIPS JITs. Conditional JMP32 operations on 64-bit MIPs
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+ * are JITed with sign extensions inserted when so expected.
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+ *
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+ * ALU operations
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+ * ==============
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+ * ALU operations on 32/64-bit MIPS and ALU64 operations on 64-bit MIPS are
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+ * JITed in the following steps. ALU64 operations on 32-bit MIPS are more
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+ * complicated and therefore only processed by special implementations in
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+ * step (3).
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+ *
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+ * 1) valid_alu_i:
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+ * Determine if an immediate operation can be emitted as such, or if
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+ * we must fall back to the register version.
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+ *
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+ * 2) rewrite_alu_i:
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+ * Convert BPF operation and immediate value to a canonical form for
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+ * JITing. In some degenerate cases this form may be a no-op.
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+ *
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+ * 3) emit_alu_{i,i64,r,64}:
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+ * Emit instructions for an ALU or ALU64 immediate or register operation.
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+ *
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+ * JMP operations
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+ * ==============
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+ * JMP and JMP32 operations require an JIT instruction offset table for
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+ * translating the jump offset. This table is computed by dry-running the
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+ * JIT without actually emitting anything. However, the computed PC-relative
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+ * offset may overflow the 18-bit offset field width of the native MIPS
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+ * branch instruction. In such cases, the long jump is converted into the
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+ * following sequence.
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+ *
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+ * <branch> !<cond> +2 Inverted PC-relative branch
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+ * nop Delay slot
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+ * j <offset> Unconditional absolute long jump
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+ * nop Delay slot
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+ *
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+ * Since this converted sequence alters the offset table, all offsets must
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+ * be re-calculated. This may in turn trigger new branch conversions, so
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+ * the process is repeated until no further changes are made. Normally it
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+ * completes in 1-2 iterations. If JIT_MAX_ITERATIONS should reached, we
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+ * fall back to converting every remaining jump operation. The branch
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+ * conversion is independent of how the JMP or JMP32 condition is JITed.
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+ *
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+ * JMP32 and JMP operations are JITed as follows.
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+ *
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+ * 1) setup_jmp_{i,r}:
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+ * Convert jump conditional and offset into a form that can be JITed.
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+ * This form may be a no-op, a canonical form, or an inverted PC-relative
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+ * jump if branch conversion is necessary.
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+ *
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+ * 2) valid_jmp_i:
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+ * Determine if an immediate operations can be emitted as such, or if
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+ * we must fall back to the register version. Applies to JMP32 for 32-bit
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+ * MIPS, and both JMP and JMP32 for 64-bit MIPS.
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+ *
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+ * 3) emit_jmp_{i,i64,r,r64}:
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+ * Emit instructions for an JMP or JMP32 immediate or register operation.
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+ *
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+ * 4) finish_jmp_{i,r}:
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+ * Emit any instructions needed to finish the jump. This includes a nop
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+ * for the delay slot if a branch was emitted, and a long absolute jump
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+ * if the branch was converted.
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+ */
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+
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+#include <linux/limits.h>
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+#include <linux/bitops.h>
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+#include <linux/errno.h>
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+#include <linux/filter.h>
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+#include <linux/bpf.h>
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+#include <linux/slab.h>
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+#include <asm/bitops.h>
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+#include <asm/cacheflush.h>
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+#include <asm/cpu-features.h>
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+#include <asm/isa-rev.h>
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+#include <asm/uasm.h>
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+
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+#include "bpf_jit_comp.h"
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+
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+/* Convenience macros for descriptor access */
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+#define CONVERTED(desc) ((desc) & JIT_DESC_CONVERT)
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+#define INDEX(desc) ((desc) & ~JIT_DESC_CONVERT)
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+
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+/*
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+ * Push registers on the stack, starting at a given depth from the stack
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+ * pointer and increasing. The next depth to be written is returned.
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+ */
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+int push_regs(struct jit_context *ctx, u32 mask, u32 excl, int depth)
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+{
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+ int reg;
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+
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+ for (reg = 0; reg < BITS_PER_BYTE * sizeof(mask); reg++)
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+ if (mask & BIT(reg)) {
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+ if ((excl & BIT(reg)) == 0) {
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+ if (sizeof(long) == 4)
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+ emit(ctx, sw, reg, depth, MIPS_R_SP);
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+ else /* sizeof(long) == 8 */
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+ emit(ctx, sd, reg, depth, MIPS_R_SP);
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+ }
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+ depth += sizeof(long);
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+ }
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+
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+ ctx->stack_used = max((int)ctx->stack_used, depth);
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+ return depth;
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+}
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+
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+/*
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+ * Pop registers from the stack, starting at a given depth from the stack
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+ * pointer and increasing. The next depth to be read is returned.
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+ */
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+int pop_regs(struct jit_context *ctx, u32 mask, u32 excl, int depth)
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+{
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+ int reg;
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+
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+ for (reg = 0; reg < BITS_PER_BYTE * sizeof(mask); reg++)
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+ if (mask & BIT(reg)) {
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+ if ((excl & BIT(reg)) == 0) {
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+ if (sizeof(long) == 4)
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+ emit(ctx, lw, reg, depth, MIPS_R_SP);
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+ else /* sizeof(long) == 8 */
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+ emit(ctx, ld, reg, depth, MIPS_R_SP);
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+ }
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+ depth += sizeof(long);
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+ }
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+
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+ return depth;
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+}
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+
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+/* Compute the 28-bit jump target address from a BPF program location */
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+int get_target(struct jit_context *ctx, u32 loc)
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+{
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+ u32 index = INDEX(ctx->descriptors[loc]);
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+ unsigned long pc = (unsigned long)&ctx->target[ctx->jit_index];
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+ unsigned long addr = (unsigned long)&ctx->target[index];
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+
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+ if (!ctx->target)
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+ return 0;
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+
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+ if ((addr ^ pc) & ~MIPS_JMP_MASK)
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+ return -1;
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+
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+ return addr & MIPS_JMP_MASK;
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+}
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+
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+/* Compute the PC-relative offset to relative BPF program offset */
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+int get_offset(const struct jit_context *ctx, int off)
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+{
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+ return (INDEX(ctx->descriptors[ctx->bpf_index + off]) -
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+ ctx->jit_index - 1) * sizeof(u32);
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+}
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+
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+/* dst = imm (register width) */
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+void emit_mov_i(struct jit_context *ctx, u8 dst, s32 imm)
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+{
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+ if (imm >= -0x8000 && imm <= 0x7fff) {
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+ emit(ctx, addiu, dst, MIPS_R_ZERO, imm);
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+ } else {
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+ emit(ctx, lui, dst, (s16)((u32)imm >> 16));
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+ emit(ctx, ori, dst, dst, (u16)(imm & 0xffff));
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+ }
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+ clobber_reg(ctx, dst);
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+}
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+
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+/* dst = src (register width) */
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+void emit_mov_r(struct jit_context *ctx, u8 dst, u8 src)
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+{
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+ emit(ctx, ori, dst, src, 0);
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+ clobber_reg(ctx, dst);
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+}
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+
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+/* Validate ALU immediate range */
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+bool valid_alu_i(u8 op, s32 imm)
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+{
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+ switch (BPF_OP(op)) {
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+ case BPF_NEG:
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+ case BPF_LSH:
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+ case BPF_RSH:
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+ case BPF_ARSH:
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+ /* All legal eBPF values are valid */
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+ return true;
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+ case BPF_ADD:
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+ /* imm must be 16 bits */
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+ return imm >= -0x8000 && imm <= 0x7fff;
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+ case BPF_SUB:
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+ /* -imm must be 16 bits */
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+ return imm >= -0x7fff && imm <= 0x8000;
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+ case BPF_AND:
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+ case BPF_OR:
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+ case BPF_XOR:
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+ /* imm must be 16 bits unsigned */
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+ return imm >= 0 && imm <= 0xffff;
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+ case BPF_MUL:
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+ /* imm must be zero or a positive power of two */
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+ return imm == 0 || (imm > 0 && is_power_of_2(imm));
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+ case BPF_DIV:
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+ case BPF_MOD:
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+ /* imm must be an 17-bit power of two */
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+ return (u32)imm <= 0x10000 && is_power_of_2((u32)imm);
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+ }
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+ return false;
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+}
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+
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+/* Rewrite ALU immediate operation */
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+bool rewrite_alu_i(u8 op, s32 imm, u8 *alu, s32 *val)
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+{
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+ bool act = true;
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+
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+ switch (BPF_OP(op)) {
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+ case BPF_LSH:
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+ case BPF_RSH:
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+ case BPF_ARSH:
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+ case BPF_ADD:
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+ case BPF_SUB:
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+ case BPF_OR:
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+ case BPF_XOR:
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+ /* imm == 0 is a no-op */
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+ act = imm != 0;
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+ break;
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+ case BPF_MUL:
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+ if (imm == 1) {
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+ /* dst * 1 is a no-op */
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+ act = false;
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+ } else if (imm == 0) {
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+ /* dst * 0 is dst & 0 */
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+ op = BPF_AND;
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+ } else {
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+ /* dst * (1 << n) is dst << n */
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+ op = BPF_LSH;
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+ imm = ilog2(abs(imm));
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+ }
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+ break;
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+ case BPF_DIV:
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+ if (imm == 1) {
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+ /* dst / 1 is a no-op */
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+ act = false;
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+ } else {
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+ /* dst / (1 << n) is dst >> n */
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+ op = BPF_RSH;
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+ imm = ilog2(imm);
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+ }
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+ break;
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+ case BPF_MOD:
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+ /* dst % (1 << n) is dst & ((1 << n) - 1) */
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+ op = BPF_AND;
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+ imm--;
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+ break;
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+ }
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+
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+ *alu = op;
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+ *val = imm;
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+ return act;
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+}
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+
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+/* ALU immediate operation (32-bit) */
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+void emit_alu_i(struct jit_context *ctx, u8 dst, s32 imm, u8 op)
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+{
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+ switch (BPF_OP(op)) {
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+ /* dst = -dst */
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+ case BPF_NEG:
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+ emit(ctx, subu, dst, MIPS_R_ZERO, dst);
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+ break;
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+ /* dst = dst & imm */
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+ case BPF_AND:
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+ emit(ctx, andi, dst, dst, (u16)imm);
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+ break;
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+ /* dst = dst | imm */
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+ case BPF_OR:
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+ emit(ctx, ori, dst, dst, (u16)imm);
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+ break;
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+ /* dst = dst ^ imm */
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+ case BPF_XOR:
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+ emit(ctx, xori, dst, dst, (u16)imm);
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+ break;
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+ /* dst = dst << imm */
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+ case BPF_LSH:
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+ emit(ctx, sll, dst, dst, imm);
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+ break;
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+ /* dst = dst >> imm */
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+ case BPF_RSH:
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+ emit(ctx, srl, dst, dst, imm);
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+ break;
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+ /* dst = dst >> imm (arithmetic) */
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+ case BPF_ARSH:
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+ emit(ctx, sra, dst, dst, imm);
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+ break;
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+ /* dst = dst + imm */
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+ case BPF_ADD:
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+ emit(ctx, addiu, dst, dst, imm);
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+ break;
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+ /* dst = dst - imm */
|
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+ case BPF_SUB:
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+ emit(ctx, addiu, dst, dst, -imm);
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+ break;
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+ }
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+ clobber_reg(ctx, dst);
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+}
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+
|
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+/* ALU register operation (32-bit) */
|
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+void emit_alu_r(struct jit_context *ctx, u8 dst, u8 src, u8 op)
|
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+{
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+ switch (BPF_OP(op)) {
|
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+ /* dst = dst & src */
|
|
+ case BPF_AND:
|
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+ emit(ctx, and, dst, dst, src);
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+ break;
|
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+ /* dst = dst | src */
|
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+ case BPF_OR:
|
|
+ emit(ctx, or, dst, dst, src);
|
|
+ break;
|
|
+ /* dst = dst ^ src */
|
|
+ case BPF_XOR:
|
|
+ emit(ctx, xor, dst, dst, src);
|
|
+ break;
|
|
+ /* dst = dst << src */
|
|
+ case BPF_LSH:
|
|
+ emit(ctx, sllv, dst, dst, src);
|
|
+ break;
|
|
+ /* dst = dst >> src */
|
|
+ case BPF_RSH:
|
|
+ emit(ctx, srlv, dst, dst, src);
|
|
+ break;
|
|
+ /* dst = dst >> src (arithmetic) */
|
|
+ case BPF_ARSH:
|
|
+ emit(ctx, srav, dst, dst, src);
|
|
+ break;
|
|
+ /* dst = dst + src */
|
|
+ case BPF_ADD:
|
|
+ emit(ctx, addu, dst, dst, src);
|
|
+ break;
|
|
+ /* dst = dst - src */
|
|
+ case BPF_SUB:
|
|
+ emit(ctx, subu, dst, dst, src);
|
|
+ break;
|
|
+ /* dst = dst * src */
|
|
+ case BPF_MUL:
|
|
+ if (cpu_has_mips32r1 || cpu_has_mips32r6) {
|
|
+ emit(ctx, mul, dst, dst, src);
|
|
+ } else {
|
|
+ emit(ctx, multu, dst, src);
|
|
+ emit(ctx, mflo, dst);
|
|
+ }
|
|
+ break;
|
|
+ /* dst = dst / src */
|
|
+ case BPF_DIV:
|
|
+ if (cpu_has_mips32r6) {
|
|
+ emit(ctx, divu_r6, dst, dst, src);
|
|
+ } else {
|
|
+ emit(ctx, divu, dst, src);
|
|
+ emit(ctx, mflo, dst);
|
|
+ }
|
|
+ break;
|
|
+ /* dst = dst % src */
|
|
+ case BPF_MOD:
|
|
+ if (cpu_has_mips32r6) {
|
|
+ emit(ctx, modu, dst, dst, src);
|
|
+ } else {
|
|
+ emit(ctx, divu, dst, src);
|
|
+ emit(ctx, mfhi, dst);
|
|
+ }
|
|
+ break;
|
|
+ }
|
|
+ clobber_reg(ctx, dst);
|
|
+}
|
|
+
|
|
+/* Atomic read-modify-write (32-bit) */
|
|
+void emit_atomic_r(struct jit_context *ctx, u8 dst, u8 src, s16 off, u8 code)
|
|
+{
|
|
+ emit(ctx, ll, MIPS_R_T9, off, dst);
|
|
+ switch (code) {
|
|
+ case BPF_ADD:
|
|
+ emit(ctx, addu, MIPS_R_T8, MIPS_R_T9, src);
|
|
+ break;
|
|
+ case BPF_AND:
|
|
+ emit(ctx, and, MIPS_R_T8, MIPS_R_T9, src);
|
|
+ break;
|
|
+ case BPF_OR:
|
|
+ emit(ctx, or, MIPS_R_T8, MIPS_R_T9, src);
|
|
+ break;
|
|
+ case BPF_XOR:
|
|
+ emit(ctx, xor, MIPS_R_T8, MIPS_R_T9, src);
|
|
+ break;
|
|
+ }
|
|
+ emit(ctx, sc, MIPS_R_T8, off, dst);
|
|
+ emit(ctx, beqz, MIPS_R_T8, -16);
|
|
+ emit(ctx, nop); /* Delay slot */
|
|
+}
|
|
+
|
|
+/* Atomic compare-and-exchange (32-bit) */
|
|
+void emit_cmpxchg_r(struct jit_context *ctx, u8 dst, u8 src, u8 res, s16 off)
|
|
+{
|
|
+ emit(ctx, ll, MIPS_R_T9, off, dst);
|
|
+ emit(ctx, bne, MIPS_R_T9, res, 12);
|
|
+ emit(ctx, move, MIPS_R_T8, src); /* Delay slot */
|
|
+ emit(ctx, sc, MIPS_R_T8, off, dst);
|
|
+ emit(ctx, beqz, MIPS_R_T8, -20);
|
|
+ emit(ctx, move, res, MIPS_R_T9); /* Delay slot */
|
|
+ clobber_reg(ctx, res);
|
|
+}
|
|
+
|
|
+/* Swap bytes and truncate a register word or half word */
|
|
+void emit_bswap_r(struct jit_context *ctx, u8 dst, u32 width)
|
|
+{
|
|
+ u8 tmp = MIPS_R_T8;
|
|
+ u8 msk = MIPS_R_T9;
|
|
+
|
|
+ switch (width) {
|
|
+ /* Swap bytes in a word */
|
|
+ case 32:
|
|
+ if (cpu_has_mips32r2 || cpu_has_mips32r6) {
|
|
+ emit(ctx, wsbh, dst, dst);
|
|
+ emit(ctx, rotr, dst, dst, 16);
|
|
+ } else {
|
|
+ emit(ctx, sll, tmp, dst, 16); /* tmp = dst << 16 */
|
|
+ emit(ctx, srl, dst, dst, 16); /* dst = dst >> 16 */
|
|
+ emit(ctx, or, dst, dst, tmp); /* dst = dst | tmp */
|
|
+
|
|
+ emit(ctx, lui, msk, 0xff); /* msk = 0x00ff0000 */
|
|
+ emit(ctx, ori, msk, msk, 0xff); /* msk = msk | 0xff */
|
|
+
|
|
+ emit(ctx, and, tmp, dst, msk); /* tmp = dst & msk */
|
|
+ emit(ctx, sll, tmp, tmp, 8); /* tmp = tmp << 8 */
|
|
+ emit(ctx, srl, dst, dst, 8); /* dst = dst >> 8 */
|
|
+ emit(ctx, and, dst, dst, msk); /* dst = dst & msk */
|
|
+ emit(ctx, or, dst, dst, tmp); /* reg = dst | tmp */
|
|
+ }
|
|
+ break;
|
|
+ /* Swap bytes in a half word */
|
|
+ case 16:
|
|
+ if (cpu_has_mips32r2 || cpu_has_mips32r6) {
|
|
+ emit(ctx, wsbh, dst, dst);
|
|
+ emit(ctx, andi, dst, dst, 0xffff);
|
|
+ } else {
|
|
+ emit(ctx, andi, tmp, dst, 0xff00); /* t = d & 0xff00 */
|
|
+ emit(ctx, srl, tmp, tmp, 8); /* t = t >> 8 */
|
|
+ emit(ctx, andi, dst, dst, 0x00ff); /* d = d & 0x00ff */
|
|
+ emit(ctx, sll, dst, dst, 8); /* d = d << 8 */
|
|
+ emit(ctx, or, dst, dst, tmp); /* d = d | t */
|
|
+ }
|
|
+ break;
|
|
+ }
|
|
+ clobber_reg(ctx, dst);
|
|
+}
|
|
+
|
|
+/* Validate jump immediate range */
|
|
+bool valid_jmp_i(u8 op, s32 imm)
|
|
+{
|
|
+ switch (op) {
|
|
+ case JIT_JNOP:
|
|
+ /* Immediate value not used */
|
|
+ return true;
|
|
+ case BPF_JEQ:
|
|
+ case BPF_JNE:
|
|
+ /* No immediate operation */
|
|
+ return false;
|
|
+ case BPF_JSET:
|
|
+ case JIT_JNSET:
|
|
+ /* imm must be 16 bits unsigned */
|
|
+ return imm >= 0 && imm <= 0xffff;
|
|
+ case BPF_JGE:
|
|
+ case BPF_JLT:
|
|
+ case BPF_JSGE:
|
|
+ case BPF_JSLT:
|
|
+ /* imm must be 16 bits */
|
|
+ return imm >= -0x8000 && imm <= 0x7fff;
|
|
+ case BPF_JGT:
|
|
+ case BPF_JLE:
|
|
+ case BPF_JSGT:
|
|
+ case BPF_JSLE:
|
|
+ /* imm + 1 must be 16 bits */
|
|
+ return imm >= -0x8001 && imm <= 0x7ffe;
|
|
+ }
|
|
+ return false;
|
|
+}
|
|
+
|
|
+/* Invert a conditional jump operation */
|
|
+static u8 invert_jmp(u8 op)
|
|
+{
|
|
+ switch (op) {
|
|
+ case BPF_JA: return JIT_JNOP;
|
|
+ case BPF_JEQ: return BPF_JNE;
|
|
+ case BPF_JNE: return BPF_JEQ;
|
|
+ case BPF_JSET: return JIT_JNSET;
|
|
+ case BPF_JGT: return BPF_JLE;
|
|
+ case BPF_JGE: return BPF_JLT;
|
|
+ case BPF_JLT: return BPF_JGE;
|
|
+ case BPF_JLE: return BPF_JGT;
|
|
+ case BPF_JSGT: return BPF_JSLE;
|
|
+ case BPF_JSGE: return BPF_JSLT;
|
|
+ case BPF_JSLT: return BPF_JSGE;
|
|
+ case BPF_JSLE: return BPF_JSGT;
|
|
+ }
|
|
+ return 0;
|
|
+}
|
|
+
|
|
+/* Prepare a PC-relative jump operation */
|
|
+static void setup_jmp(struct jit_context *ctx, u8 bpf_op,
|
|
+ s16 bpf_off, u8 *jit_op, s32 *jit_off)
|
|
+{
|
|
+ u32 *descp = &ctx->descriptors[ctx->bpf_index];
|
|
+ int op = bpf_op;
|
|
+ int offset = 0;
|
|
+
|
|
+ /* Do not compute offsets on the first pass */
|
|
+ if (INDEX(*descp) == 0)
|
|
+ goto done;
|
|
+
|
|
+ /* Skip jumps never taken */
|
|
+ if (bpf_op == JIT_JNOP)
|
|
+ goto done;
|
|
+
|
|
+ /* Convert jumps always taken */
|
|
+ if (bpf_op == BPF_JA)
|
|
+ *descp |= JIT_DESC_CONVERT;
|
|
+
|
|
+ /*
|
|
+ * Current ctx->jit_index points to the start of the branch preamble.
|
|
+ * Since the preamble differs among different branch conditionals,
|
|
+ * the current index cannot be used to compute the branch offset.
|
|
+ * Instead, we use the offset table value for the next instruction,
|
|
+ * which gives the index immediately after the branch delay slot.
|
|
+ */
|
|
+ if (!CONVERTED(*descp)) {
|
|
+ int target = ctx->bpf_index + bpf_off + 1;
|
|
+ int origin = ctx->bpf_index + 1;
|
|
+
|
|
+ offset = (INDEX(ctx->descriptors[target]) -
|
|
+ INDEX(ctx->descriptors[origin]) + 1) * sizeof(u32);
|
|
+ }
|
|
+
|
|
+ /*
|
|
+ * The PC-relative branch offset field on MIPS is 18 bits signed,
|
|
+ * so if the computed offset is larger than this we generate a an
|
|
+ * absolute jump that we skip with an inverted conditional branch.
|
|
+ */
|
|
+ if (CONVERTED(*descp) || offset < -0x20000 || offset > 0x1ffff) {
|
|
+ offset = 3 * sizeof(u32);
|
|
+ op = invert_jmp(bpf_op);
|
|
+ ctx->changes += !CONVERTED(*descp);
|
|
+ *descp |= JIT_DESC_CONVERT;
|
|
+ }
|
|
+
|
|
+done:
|
|
+ *jit_off = offset;
|
|
+ *jit_op = op;
|
|
+}
|
|
+
|
|
+/* Prepare a PC-relative jump operation with immediate conditional */
|
|
+void setup_jmp_i(struct jit_context *ctx, s32 imm, u8 width,
|
|
+ u8 bpf_op, s16 bpf_off, u8 *jit_op, s32 *jit_off)
|
|
+{
|
|
+ bool always = false;
|
|
+ bool never = false;
|
|
+
|
|
+ switch (bpf_op) {
|
|
+ case BPF_JEQ:
|
|
+ case BPF_JNE:
|
|
+ break;
|
|
+ case BPF_JSET:
|
|
+ case BPF_JLT:
|
|
+ never = imm == 0;
|
|
+ break;
|
|
+ case BPF_JGE:
|
|
+ always = imm == 0;
|
|
+ break;
|
|
+ case BPF_JGT:
|
|
+ never = (u32)imm == U32_MAX;
|
|
+ break;
|
|
+ case BPF_JLE:
|
|
+ always = (u32)imm == U32_MAX;
|
|
+ break;
|
|
+ case BPF_JSGT:
|
|
+ never = imm == S32_MAX && width == 32;
|
|
+ break;
|
|
+ case BPF_JSGE:
|
|
+ always = imm == S32_MIN && width == 32;
|
|
+ break;
|
|
+ case BPF_JSLT:
|
|
+ never = imm == S32_MIN && width == 32;
|
|
+ break;
|
|
+ case BPF_JSLE:
|
|
+ always = imm == S32_MAX && width == 32;
|
|
+ break;
|
|
+ }
|
|
+
|
|
+ if (never)
|
|
+ bpf_op = JIT_JNOP;
|
|
+ if (always)
|
|
+ bpf_op = BPF_JA;
|
|
+ setup_jmp(ctx, bpf_op, bpf_off, jit_op, jit_off);
|
|
+}
|
|
+
|
|
+/* Prepare a PC-relative jump operation with register conditional */
|
|
+void setup_jmp_r(struct jit_context *ctx, bool same_reg,
|
|
+ u8 bpf_op, s16 bpf_off, u8 *jit_op, s32 *jit_off)
|
|
+{
|
|
+ switch (bpf_op) {
|
|
+ case BPF_JSET:
|
|
+ break;
|
|
+ case BPF_JEQ:
|
|
+ case BPF_JGE:
|
|
+ case BPF_JLE:
|
|
+ case BPF_JSGE:
|
|
+ case BPF_JSLE:
|
|
+ if (same_reg)
|
|
+ bpf_op = BPF_JA;
|
|
+ break;
|
|
+ case BPF_JNE:
|
|
+ case BPF_JLT:
|
|
+ case BPF_JGT:
|
|
+ case BPF_JSGT:
|
|
+ case BPF_JSLT:
|
|
+ if (same_reg)
|
|
+ bpf_op = JIT_JNOP;
|
|
+ break;
|
|
+ }
|
|
+ setup_jmp(ctx, bpf_op, bpf_off, jit_op, jit_off);
|
|
+}
|
|
+
|
|
+/* Finish a PC-relative jump operation */
|
|
+int finish_jmp(struct jit_context *ctx, u8 jit_op, s16 bpf_off)
|
|
+{
|
|
+ /* Emit conditional branch delay slot */
|
|
+ if (jit_op != JIT_JNOP)
|
|
+ emit(ctx, nop);
|
|
+ /*
|
|
+ * Emit an absolute long jump with delay slot,
|
|
+ * if the PC-relative branch was converted.
|
|
+ */
|
|
+ if (CONVERTED(ctx->descriptors[ctx->bpf_index])) {
|
|
+ int target = get_target(ctx, ctx->bpf_index + bpf_off + 1);
|
|
+
|
|
+ if (target < 0)
|
|
+ return -1;
|
|
+ emit(ctx, j, target);
|
|
+ emit(ctx, nop);
|
|
+ }
|
|
+ return 0;
|
|
+}
|
|
+
|
|
+/* Jump immediate (32-bit) */
|
|
+void emit_jmp_i(struct jit_context *ctx, u8 dst, s32 imm, s32 off, u8 op)
|
|
+{
|
|
+ switch (op) {
|
|
+ /* No-op, used internally for branch optimization */
|
|
+ case JIT_JNOP:
|
|
+ break;
|
|
+ /* PC += off if dst & imm */
|
|
+ case BPF_JSET:
|
|
+ emit(ctx, andi, MIPS_R_T9, dst, (u16)imm);
|
|
+ emit(ctx, bnez, MIPS_R_T9, off);
|
|
+ break;
|
|
+ /* PC += off if (dst & imm) == 0 (not in BPF, used for long jumps) */
|
|
+ case JIT_JNSET:
|
|
+ emit(ctx, andi, MIPS_R_T9, dst, (u16)imm);
|
|
+ emit(ctx, beqz, MIPS_R_T9, off);
|
|
+ break;
|
|
+ /* PC += off if dst > imm */
|
|
+ case BPF_JGT:
|
|
+ emit(ctx, sltiu, MIPS_R_T9, dst, imm + 1);
|
|
+ emit(ctx, beqz, MIPS_R_T9, off);
|
|
+ break;
|
|
+ /* PC += off if dst >= imm */
|
|
+ case BPF_JGE:
|
|
+ emit(ctx, sltiu, MIPS_R_T9, dst, imm);
|
|
+ emit(ctx, beqz, MIPS_R_T9, off);
|
|
+ break;
|
|
+ /* PC += off if dst < imm */
|
|
+ case BPF_JLT:
|
|
+ emit(ctx, sltiu, MIPS_R_T9, dst, imm);
|
|
+ emit(ctx, bnez, MIPS_R_T9, off);
|
|
+ break;
|
|
+ /* PC += off if dst <= imm */
|
|
+ case BPF_JLE:
|
|
+ emit(ctx, sltiu, MIPS_R_T9, dst, imm + 1);
|
|
+ emit(ctx, bnez, MIPS_R_T9, off);
|
|
+ break;
|
|
+ /* PC += off if dst > imm (signed) */
|
|
+ case BPF_JSGT:
|
|
+ emit(ctx, slti, MIPS_R_T9, dst, imm + 1);
|
|
+ emit(ctx, beqz, MIPS_R_T9, off);
|
|
+ break;
|
|
+ /* PC += off if dst >= imm (signed) */
|
|
+ case BPF_JSGE:
|
|
+ emit(ctx, slti, MIPS_R_T9, dst, imm);
|
|
+ emit(ctx, beqz, MIPS_R_T9, off);
|
|
+ break;
|
|
+ /* PC += off if dst < imm (signed) */
|
|
+ case BPF_JSLT:
|
|
+ emit(ctx, slti, MIPS_R_T9, dst, imm);
|
|
+ emit(ctx, bnez, MIPS_R_T9, off);
|
|
+ break;
|
|
+ /* PC += off if dst <= imm (signed) */
|
|
+ case BPF_JSLE:
|
|
+ emit(ctx, slti, MIPS_R_T9, dst, imm + 1);
|
|
+ emit(ctx, bnez, MIPS_R_T9, off);
|
|
+ break;
|
|
+ }
|
|
+}
|
|
+
|
|
+/* Jump register (32-bit) */
|
|
+void emit_jmp_r(struct jit_context *ctx, u8 dst, u8 src, s32 off, u8 op)
|
|
+{
|
|
+ switch (op) {
|
|
+ /* No-op, used internally for branch optimization */
|
|
+ case JIT_JNOP:
|
|
+ break;
|
|
+ /* PC += off if dst == src */
|
|
+ case BPF_JEQ:
|
|
+ emit(ctx, beq, dst, src, off);
|
|
+ break;
|
|
+ /* PC += off if dst != src */
|
|
+ case BPF_JNE:
|
|
+ emit(ctx, bne, dst, src, off);
|
|
+ break;
|
|
+ /* PC += off if dst & src */
|
|
+ case BPF_JSET:
|
|
+ emit(ctx, and, MIPS_R_T9, dst, src);
|
|
+ emit(ctx, bnez, MIPS_R_T9, off);
|
|
+ break;
|
|
+ /* PC += off if (dst & imm) == 0 (not in BPF, used for long jumps) */
|
|
+ case JIT_JNSET:
|
|
+ emit(ctx, and, MIPS_R_T9, dst, src);
|
|
+ emit(ctx, beqz, MIPS_R_T9, off);
|
|
+ break;
|
|
+ /* PC += off if dst > src */
|
|
+ case BPF_JGT:
|
|
+ emit(ctx, sltu, MIPS_R_T9, src, dst);
|
|
+ emit(ctx, bnez, MIPS_R_T9, off);
|
|
+ break;
|
|
+ /* PC += off if dst >= src */
|
|
+ case BPF_JGE:
|
|
+ emit(ctx, sltu, MIPS_R_T9, dst, src);
|
|
+ emit(ctx, beqz, MIPS_R_T9, off);
|
|
+ break;
|
|
+ /* PC += off if dst < src */
|
|
+ case BPF_JLT:
|
|
+ emit(ctx, sltu, MIPS_R_T9, dst, src);
|
|
+ emit(ctx, bnez, MIPS_R_T9, off);
|
|
+ break;
|
|
+ /* PC += off if dst <= src */
|
|
+ case BPF_JLE:
|
|
+ emit(ctx, sltu, MIPS_R_T9, src, dst);
|
|
+ emit(ctx, beqz, MIPS_R_T9, off);
|
|
+ break;
|
|
+ /* PC += off if dst > src (signed) */
|
|
+ case BPF_JSGT:
|
|
+ emit(ctx, slt, MIPS_R_T9, src, dst);
|
|
+ emit(ctx, bnez, MIPS_R_T9, off);
|
|
+ break;
|
|
+ /* PC += off if dst >= src (signed) */
|
|
+ case BPF_JSGE:
|
|
+ emit(ctx, slt, MIPS_R_T9, dst, src);
|
|
+ emit(ctx, beqz, MIPS_R_T9, off);
|
|
+ break;
|
|
+ /* PC += off if dst < src (signed) */
|
|
+ case BPF_JSLT:
|
|
+ emit(ctx, slt, MIPS_R_T9, dst, src);
|
|
+ emit(ctx, bnez, MIPS_R_T9, off);
|
|
+ break;
|
|
+ /* PC += off if dst <= src (signed) */
|
|
+ case BPF_JSLE:
|
|
+ emit(ctx, slt, MIPS_R_T9, src, dst);
|
|
+ emit(ctx, beqz, MIPS_R_T9, off);
|
|
+ break;
|
|
+ }
|
|
+}
|
|
+
|
|
+/* Jump always */
|
|
+int emit_ja(struct jit_context *ctx, s16 off)
|
|
+{
|
|
+ int target = get_target(ctx, ctx->bpf_index + off + 1);
|
|
+
|
|
+ if (target < 0)
|
|
+ return -1;
|
|
+ emit(ctx, j, target);
|
|
+ emit(ctx, nop);
|
|
+ return 0;
|
|
+}
|
|
+
|
|
+/* Jump to epilogue */
|
|
+int emit_exit(struct jit_context *ctx)
|
|
+{
|
|
+ int target = get_target(ctx, ctx->program->len);
|
|
+
|
|
+ if (target < 0)
|
|
+ return -1;
|
|
+ emit(ctx, j, target);
|
|
+ emit(ctx, nop);
|
|
+ return 0;
|
|
+}
|
|
+
|
|
+/* Build the program body from eBPF bytecode */
|
|
+static int build_body(struct jit_context *ctx)
|
|
+{
|
|
+ const struct bpf_prog *prog = ctx->program;
|
|
+ unsigned int i;
|
|
+
|
|
+ ctx->stack_used = 0;
|
|
+ for (i = 0; i < prog->len; i++) {
|
|
+ const struct bpf_insn *insn = &prog->insnsi[i];
|
|
+ u32 *descp = &ctx->descriptors[i];
|
|
+ int ret;
|
|
+
|
|
+ access_reg(ctx, insn->src_reg);
|
|
+ access_reg(ctx, insn->dst_reg);
|
|
+
|
|
+ ctx->bpf_index = i;
|
|
+ if (ctx->target == NULL) {
|
|
+ ctx->changes += INDEX(*descp) != ctx->jit_index;
|
|
+ *descp &= JIT_DESC_CONVERT;
|
|
+ *descp |= ctx->jit_index;
|
|
+ }
|
|
+
|
|
+ ret = build_insn(insn, ctx);
|
|
+ if (ret < 0)
|
|
+ return ret;
|
|
+
|
|
+ if (ret > 0) {
|
|
+ i++;
|
|
+ if (ctx->target == NULL)
|
|
+ descp[1] = ctx->jit_index;
|
|
+ }
|
|
+ }
|
|
+
|
|
+ /* Store the end offset, where the epilogue begins */
|
|
+ ctx->descriptors[prog->len] = ctx->jit_index;
|
|
+ return 0;
|
|
+}
|
|
+
|
|
+/* Set the branch conversion flag on all instructions */
|
|
+static void set_convert_flag(struct jit_context *ctx, bool enable)
|
|
+{
|
|
+ const struct bpf_prog *prog = ctx->program;
|
|
+ u32 flag = enable ? JIT_DESC_CONVERT : 0;
|
|
+ unsigned int i;
|
|
+
|
|
+ for (i = 0; i <= prog->len; i++)
|
|
+ ctx->descriptors[i] = INDEX(ctx->descriptors[i]) | flag;
|
|
+}
|
|
+
|
|
+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 */
|
|
+}
|
|
+
|
|
+bool bpf_jit_needs_zext(void)
|
|
+{
|
|
+ return true;
|
|
+}
|
|
+
|
|
+struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
|
|
+{
|
|
+ struct bpf_prog *tmp, *orig_prog = prog;
|
|
+ struct bpf_binary_header *header = NULL;
|
|
+ struct jit_context ctx;
|
|
+ bool tmp_blinded = false;
|
|
+ unsigned int tmp_idx;
|
|
+ unsigned int image_size;
|
|
+ u8 *image_ptr;
|
|
+ int tries;
|
|
+
|
|
+ /*
|
|
+ * If BPF JIT was not enabled then we must fall back to
|
|
+ * the interpreter.
|
|
+ */
|
|
+ if (!prog->jit_requested)
|
|
+ return orig_prog;
|
|
+ /*
|
|
+ * If constant blinding was enabled and we failed during blinding
|
|
+ * then we must fall back to the interpreter. Otherwise, we save
|
|
+ * the new JITed code.
|
|
+ */
|
|
+ tmp = bpf_jit_blind_constants(prog);
|
|
+ if (IS_ERR(tmp))
|
|
+ return orig_prog;
|
|
+ if (tmp != prog) {
|
|
+ tmp_blinded = true;
|
|
+ prog = tmp;
|
|
+ }
|
|
+
|
|
+ memset(&ctx, 0, sizeof(ctx));
|
|
+ ctx.program = prog;
|
|
+
|
|
+ /*
|
|
+ * Not able to allocate memory for descriptors[], then
|
|
+ * we must fall back to the interpreter
|
|
+ */
|
|
+ ctx.descriptors = kcalloc(prog->len + 1, sizeof(*ctx.descriptors),
|
|
+ GFP_KERNEL);
|
|
+ if (ctx.descriptors == NULL)
|
|
+ goto out_err;
|
|
+
|
|
+ /* First pass discovers used resources */
|
|
+ if (build_body(&ctx) < 0)
|
|
+ goto out_err;
|
|
+ /*
|
|
+ * Second pass computes instruction offsets.
|
|
+ * If any PC-relative branches are out of range, a sequence of
|
|
+ * a PC-relative branch + a jump 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.
|
|
+ * The last two iterations are done with all branches being
|
|
+ * converted, to guarantee offset table convergence within a
|
|
+ * fixed number of iterations.
|
|
+ */
|
|
+ ctx.jit_index = 0;
|
|
+ build_prologue(&ctx);
|
|
+ tmp_idx = ctx.jit_index;
|
|
+
|
|
+ tries = JIT_MAX_ITERATIONS;
|
|
+ do {
|
|
+ ctx.jit_index = tmp_idx;
|
|
+ ctx.changes = 0;
|
|
+ if (tries == 2)
|
|
+ set_convert_flag(&ctx, true);
|
|
+ if (build_body(&ctx) < 0)
|
|
+ goto out_err;
|
|
+ } while (ctx.changes > 0 && --tries > 0);
|
|
+
|
|
+ if (WARN_ONCE(ctx.changes > 0, "JIT offsets failed to converge"))
|
|
+ goto out_err;
|
|
+
|
|
+ build_epilogue(&ctx, MIPS_R_RA);
|
|
+
|
|
+ /* Now we know the size of the structure to make */
|
|
+ image_size = sizeof(u32) * ctx.jit_index;
|
|
+ header = bpf_jit_binary_alloc(image_size, &image_ptr,
|
|
+ sizeof(u32), jit_fill_hole);
|
|
+ /*
|
|
+ * Not able to allocate memory for the structure then
|
|
+ * we must fall back to the interpretation
|
|
+ */
|
|
+ if (header == NULL)
|
|
+ goto out_err;
|
|
+
|
|
+ /* Actual pass to generate final JIT code */
|
|
+ ctx.target = (u32 *)image_ptr;
|
|
+ ctx.jit_index = 0;
|
|
+
|
|
+ /*
|
|
+ * If building the JITed code fails somehow,
|
|
+ * we fall back to the interpretation.
|
|
+ */
|
|
+ build_prologue(&ctx);
|
|
+ if (build_body(&ctx) < 0)
|
|
+ goto out_err;
|
|
+ build_epilogue(&ctx, MIPS_R_RA);
|
|
+
|
|
+ /* Populate line info meta data */
|
|
+ set_convert_flag(&ctx, false);
|
|
+ bpf_prog_fill_jited_linfo(prog, &ctx.descriptors[1]);
|
|
+
|
|
+ /* Set as read-only exec and flush instruction cache */
|
|
+ bpf_jit_binary_lock_ro(header);
|
|
+ flush_icache_range((unsigned long)header,
|
|
+ (unsigned long)&ctx.target[ctx.jit_index]);
|
|
+
|
|
+ if (bpf_jit_enable > 1)
|
|
+ bpf_jit_dump(prog->len, image_size, 2, ctx.target);
|
|
+
|
|
+ prog->bpf_func = (void *)ctx.target;
|
|
+ prog->jited = 1;
|
|
+ prog->jited_len = image_size;
|
|
+
|
|
+out:
|
|
+ if (tmp_blinded)
|
|
+ bpf_jit_prog_release_other(prog, prog == orig_prog ?
|
|
+ tmp : orig_prog);
|
|
+ kfree(ctx.descriptors);
|
|
+ return prog;
|
|
+
|
|
+out_err:
|
|
+ prog = orig_prog;
|
|
+ if (header)
|
|
+ bpf_jit_binary_free(header);
|
|
+ goto out;
|
|
+}
|
|
--- /dev/null
|
|
+++ b/arch/mips/net/bpf_jit_comp.h
|
|
@@ -0,0 +1,211 @@
|
|
+/* SPDX-License-Identifier: GPL-2.0-only */
|
|
+/*
|
|
+ * Just-In-Time compiler for eBPF bytecode on 32-bit and 64-bit MIPS.
|
|
+ *
|
|
+ * Copyright (c) 2021 Anyfi Networks AB.
|
|
+ * Author: Johan Almbladh <johan.almbladh@gmail.com>
|
|
+ *
|
|
+ * Based on code and ideas from
|
|
+ * Copyright (c) 2017 Cavium, Inc.
|
|
+ * Copyright (c) 2017 Shubham Bansal <illusionist.neo@gmail.com>
|
|
+ * Copyright (c) 2011 Mircea Gherzan <mgherzan@gmail.com>
|
|
+ */
|
|
+
|
|
+#ifndef _BPF_JIT_COMP_H
|
|
+#define _BPF_JIT_COMP_H
|
|
+
|
|
+/* MIPS registers */
|
|
+#define MIPS_R_ZERO 0 /* Const zero */
|
|
+#define MIPS_R_AT 1 /* Asm temp */
|
|
+#define MIPS_R_V0 2 /* Result */
|
|
+#define MIPS_R_V1 3 /* Result */
|
|
+#define MIPS_R_A0 4 /* Argument */
|
|
+#define MIPS_R_A1 5 /* Argument */
|
|
+#define MIPS_R_A2 6 /* Argument */
|
|
+#define MIPS_R_A3 7 /* Argument */
|
|
+#define MIPS_R_A4 8 /* Arg (n64) */
|
|
+#define MIPS_R_A5 9 /* Arg (n64) */
|
|
+#define MIPS_R_A6 10 /* Arg (n64) */
|
|
+#define MIPS_R_A7 11 /* Arg (n64) */
|
|
+#define MIPS_R_T0 8 /* Temp (o32) */
|
|
+#define MIPS_R_T1 9 /* Temp (o32) */
|
|
+#define MIPS_R_T2 10 /* Temp (o32) */
|
|
+#define MIPS_R_T3 11 /* Temp (o32) */
|
|
+#define MIPS_R_T4 12 /* Temporary */
|
|
+#define MIPS_R_T5 13 /* Temporary */
|
|
+#define MIPS_R_T6 14 /* Temporary */
|
|
+#define MIPS_R_T7 15 /* Temporary */
|
|
+#define MIPS_R_S0 16 /* Saved */
|
|
+#define MIPS_R_S1 17 /* Saved */
|
|
+#define MIPS_R_S2 18 /* Saved */
|
|
+#define MIPS_R_S3 19 /* Saved */
|
|
+#define MIPS_R_S4 20 /* Saved */
|
|
+#define MIPS_R_S5 21 /* Saved */
|
|
+#define MIPS_R_S6 22 /* Saved */
|
|
+#define MIPS_R_S7 23 /* Saved */
|
|
+#define MIPS_R_T8 24 /* Temporary */
|
|
+#define MIPS_R_T9 25 /* Temporary */
|
|
+/* MIPS_R_K0 26 Reserved */
|
|
+/* MIPS_R_K1 27 Reserved */
|
|
+#define MIPS_R_GP 28 /* Global ptr */
|
|
+#define MIPS_R_SP 29 /* Stack ptr */
|
|
+#define MIPS_R_FP 30 /* Frame ptr */
|
|
+#define MIPS_R_RA 31 /* Return */
|
|
+
|
|
+/*
|
|
+ * Jump address mask for immediate jumps. The four most significant bits
|
|
+ * must be equal to PC.
|
|
+ */
|
|
+#define MIPS_JMP_MASK 0x0fffffffUL
|
|
+
|
|
+/* Maximum number of iterations in offset table computation */
|
|
+#define JIT_MAX_ITERATIONS 8
|
|
+
|
|
+/*
|
|
+ * Jump pseudo-instructions used internally
|
|
+ * for branch conversion and branch optimization.
|
|
+ */
|
|
+#define JIT_JNSET 0xe0
|
|
+#define JIT_JNOP 0xf0
|
|
+
|
|
+/* Descriptor flag for PC-relative branch conversion */
|
|
+#define JIT_DESC_CONVERT BIT(31)
|
|
+
|
|
+/* JIT context for an eBPF program */
|
|
+struct jit_context {
|
|
+ struct bpf_prog *program; /* The eBPF program being JITed */
|
|
+ u32 *descriptors; /* eBPF to JITed CPU insn descriptors */
|
|
+ u32 *target; /* JITed code buffer */
|
|
+ u32 bpf_index; /* Index of current BPF program insn */
|
|
+ u32 jit_index; /* Index of current JIT target insn */
|
|
+ u32 changes; /* Number of PC-relative branch conv */
|
|
+ u32 accessed; /* Bit mask of read eBPF registers */
|
|
+ u32 clobbered; /* Bit mask of modified CPU registers */
|
|
+ u32 stack_size; /* Total allocated stack size in bytes */
|
|
+ u32 saved_size; /* Size of callee-saved registers */
|
|
+ u32 stack_used; /* Stack size used for function calls */
|
|
+};
|
|
+
|
|
+/* Emit the instruction if the JIT memory space has been allocated */
|
|
+#define emit(ctx, func, ...) \
|
|
+do { \
|
|
+ if ((ctx)->target != NULL) { \
|
|
+ u32 *p = &(ctx)->target[ctx->jit_index]; \
|
|
+ uasm_i_##func(&p, ##__VA_ARGS__); \
|
|
+ } \
|
|
+ (ctx)->jit_index++; \
|
|
+} while (0)
|
|
+
|
|
+/*
|
|
+ * Mark a BPF register as accessed, it needs to be
|
|
+ * initialized by the program if expected, e.g. FP.
|
|
+ */
|
|
+static inline void access_reg(struct jit_context *ctx, u8 reg)
|
|
+{
|
|
+ ctx->accessed |= BIT(reg);
|
|
+}
|
|
+
|
|
+/*
|
|
+ * Mark a CPU register as clobbered, it needs to be
|
|
+ * saved/restored by the program if callee-saved.
|
|
+ */
|
|
+static inline void clobber_reg(struct jit_context *ctx, u8 reg)
|
|
+{
|
|
+ ctx->clobbered |= BIT(reg);
|
|
+}
|
|
+
|
|
+/*
|
|
+ * Push registers on the stack, starting at a given depth from the stack
|
|
+ * pointer and increasing. The next depth to be written is returned.
|
|
+ */
|
|
+int push_regs(struct jit_context *ctx, u32 mask, u32 excl, int depth);
|
|
+
|
|
+/*
|
|
+ * Pop registers from the stack, starting at a given depth from the stack
|
|
+ * pointer and increasing. The next depth to be read is returned.
|
|
+ */
|
|
+int pop_regs(struct jit_context *ctx, u32 mask, u32 excl, int depth);
|
|
+
|
|
+/* Compute the 28-bit jump target address from a BPF program location */
|
|
+int get_target(struct jit_context *ctx, u32 loc);
|
|
+
|
|
+/* Compute the PC-relative offset to relative BPF program offset */
|
|
+int get_offset(const struct jit_context *ctx, int off);
|
|
+
|
|
+/* dst = imm (32-bit) */
|
|
+void emit_mov_i(struct jit_context *ctx, u8 dst, s32 imm);
|
|
+
|
|
+/* dst = src (32-bit) */
|
|
+void emit_mov_r(struct jit_context *ctx, u8 dst, u8 src);
|
|
+
|
|
+/* Validate ALU/ALU64 immediate range */
|
|
+bool valid_alu_i(u8 op, s32 imm);
|
|
+
|
|
+/* Rewrite ALU/ALU64 immediate operation */
|
|
+bool rewrite_alu_i(u8 op, s32 imm, u8 *alu, s32 *val);
|
|
+
|
|
+/* ALU immediate operation (32-bit) */
|
|
+void emit_alu_i(struct jit_context *ctx, u8 dst, s32 imm, u8 op);
|
|
+
|
|
+/* ALU register operation (32-bit) */
|
|
+void emit_alu_r(struct jit_context *ctx, u8 dst, u8 src, u8 op);
|
|
+
|
|
+/* Atomic read-modify-write (32-bit) */
|
|
+void emit_atomic_r(struct jit_context *ctx, u8 dst, u8 src, s16 off, u8 code);
|
|
+
|
|
+/* Atomic compare-and-exchange (32-bit) */
|
|
+void emit_cmpxchg_r(struct jit_context *ctx, u8 dst, u8 src, u8 res, s16 off);
|
|
+
|
|
+/* Swap bytes and truncate a register word or half word */
|
|
+void emit_bswap_r(struct jit_context *ctx, u8 dst, u32 width);
|
|
+
|
|
+/* Validate JMP/JMP32 immediate range */
|
|
+bool valid_jmp_i(u8 op, s32 imm);
|
|
+
|
|
+/* Prepare a PC-relative jump operation with immediate conditional */
|
|
+void setup_jmp_i(struct jit_context *ctx, s32 imm, u8 width,
|
|
+ u8 bpf_op, s16 bpf_off, u8 *jit_op, s32 *jit_off);
|
|
+
|
|
+/* Prepare a PC-relative jump operation with register conditional */
|
|
+void setup_jmp_r(struct jit_context *ctx, bool same_reg,
|
|
+ u8 bpf_op, s16 bpf_off, u8 *jit_op, s32 *jit_off);
|
|
+
|
|
+/* Finish a PC-relative jump operation */
|
|
+int finish_jmp(struct jit_context *ctx, u8 jit_op, s16 bpf_off);
|
|
+
|
|
+/* Conditional JMP/JMP32 immediate */
|
|
+void emit_jmp_i(struct jit_context *ctx, u8 dst, s32 imm, s32 off, u8 op);
|
|
+
|
|
+/* Conditional JMP/JMP32 register */
|
|
+void emit_jmp_r(struct jit_context *ctx, u8 dst, u8 src, s32 off, u8 op);
|
|
+
|
|
+/* Jump always */
|
|
+int emit_ja(struct jit_context *ctx, s16 off);
|
|
+
|
|
+/* Jump to epilogue */
|
|
+int emit_exit(struct jit_context *ctx);
|
|
+
|
|
+/*
|
|
+ * Build program prologue to set up the stack and registers.
|
|
+ * This function is implemented separately for 32-bit and 64-bit JITs.
|
|
+ */
|
|
+void build_prologue(struct jit_context *ctx);
|
|
+
|
|
+/*
|
|
+ * Build the program epilogue to restore the stack and registers.
|
|
+ * This function is implemented separately for 32-bit and 64-bit JITs.
|
|
+ */
|
|
+void build_epilogue(struct jit_context *ctx, int dest_reg);
|
|
+
|
|
+/*
|
|
+ * Convert an eBPF instruction to native instruction, i.e
|
|
+ * JITs an eBPF instruction.
|
|
+ * Returns :
|
|
+ * 0 - Successfully JITed an 8-byte eBPF instruction
|
|
+ * >0 - Successfully JITed a 16-byte eBPF instruction
|
|
+ * <0 - Failed to JIT.
|
|
+ * This function is implemented separately for 32-bit and 64-bit JITs.
|
|
+ */
|
|
+int build_insn(const struct bpf_insn *insn, struct jit_context *ctx);
|
|
+
|
|
+#endif /* _BPF_JIT_COMP_H */
|
|
--- /dev/null
|
|
+++ b/arch/mips/net/bpf_jit_comp32.c
|
|
@@ -0,0 +1,1741 @@
|
|
+// SPDX-License-Identifier: GPL-2.0-only
|
|
+/*
|
|
+ * Just-In-Time compiler for eBPF bytecode on MIPS.
|
|
+ * Implementation of JIT functions for 32-bit CPUs.
|
|
+ *
|
|
+ * Copyright (c) 2021 Anyfi Networks AB.
|
|
+ * Author: Johan Almbladh <johan.almbladh@gmail.com>
|
|
+ *
|
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+ * Based on code and ideas from
|
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+ * Copyright (c) 2017 Cavium, Inc.
|
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+ * Copyright (c) 2017 Shubham Bansal <illusionist.neo@gmail.com>
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+ * Copyright (c) 2011 Mircea Gherzan <mgherzan@gmail.com>
|
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+ */
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+
|
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+#include <linux/math64.h>
|
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+#include <linux/errno.h>
|
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+#include <linux/filter.h>
|
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+#include <linux/bpf.h>
|
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+#include <asm/cpu-features.h>
|
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+#include <asm/isa-rev.h>
|
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+#include <asm/uasm.h>
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+
|
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+#include "bpf_jit_comp.h"
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+
|
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+/* MIPS a4-a7 are not available in the o32 ABI */
|
|
+#undef MIPS_R_A4
|
|
+#undef MIPS_R_A5
|
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+#undef MIPS_R_A6
|
|
+#undef MIPS_R_A7
|
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+
|
|
+/* Stack is 8-byte aligned in o32 ABI */
|
|
+#define MIPS_STACK_ALIGNMENT 8
|
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+
|
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+/*
|
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+ * The top 16 bytes of a stack frame is reserved for the callee in O32 ABI.
|
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+ * This corresponds to stack space for register arguments a0-a3.
|
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+ */
|
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+#define JIT_RESERVED_STACK 16
|
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+
|
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+/* Temporary 64-bit register used by JIT */
|
|
+#define JIT_REG_TMP MAX_BPF_JIT_REG
|
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+
|
|
+/*
|
|
+ * Number of prologue bytes to skip when doing a tail call.
|
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+ * Tail call count (TCC) initialization (8 bytes) always, plus
|
|
+ * R0-to-v0 assignment (4 bytes) if big endian.
|
|
+ */
|
|
+#ifdef __BIG_ENDIAN
|
|
+#define JIT_TCALL_SKIP 12
|
|
+#else
|
|
+#define JIT_TCALL_SKIP 8
|
|
+#endif
|
|
+
|
|
+/* CPU registers holding the callee return value */
|
|
+#define JIT_RETURN_REGS \
|
|
+ (BIT(MIPS_R_V0) | \
|
|
+ BIT(MIPS_R_V1))
|
|
+
|
|
+/* CPU registers arguments passed to callee directly */
|
|
+#define JIT_ARG_REGS \
|
|
+ (BIT(MIPS_R_A0) | \
|
|
+ BIT(MIPS_R_A1) | \
|
|
+ BIT(MIPS_R_A2) | \
|
|
+ BIT(MIPS_R_A3))
|
|
+
|
|
+/* CPU register arguments passed to callee on stack */
|
|
+#define JIT_STACK_REGS \
|
|
+ (BIT(MIPS_R_T0) | \
|
|
+ BIT(MIPS_R_T1) | \
|
|
+ BIT(MIPS_R_T2) | \
|
|
+ BIT(MIPS_R_T3) | \
|
|
+ BIT(MIPS_R_T4) | \
|
|
+ BIT(MIPS_R_T5))
|
|
+
|
|
+/* Caller-saved CPU registers */
|
|
+#define JIT_CALLER_REGS \
|
|
+ (JIT_RETURN_REGS | \
|
|
+ JIT_ARG_REGS | \
|
|
+ JIT_STACK_REGS)
|
|
+
|
|
+/* Callee-saved CPU registers */
|
|
+#define JIT_CALLEE_REGS \
|
|
+ (BIT(MIPS_R_S0) | \
|
|
+ BIT(MIPS_R_S1) | \
|
|
+ BIT(MIPS_R_S2) | \
|
|
+ BIT(MIPS_R_S3) | \
|
|
+ BIT(MIPS_R_S4) | \
|
|
+ BIT(MIPS_R_S5) | \
|
|
+ BIT(MIPS_R_S6) | \
|
|
+ BIT(MIPS_R_S7) | \
|
|
+ BIT(MIPS_R_GP) | \
|
|
+ BIT(MIPS_R_FP) | \
|
|
+ BIT(MIPS_R_RA))
|
|
+
|
|
+/*
|
|
+ * Mapping of 64-bit eBPF registers to 32-bit native MIPS registers.
|
|
+ *
|
|
+ * 1) Native register pairs are ordered according to CPU endiannes, following
|
|
+ * the MIPS convention for passing 64-bit arguments and return values.
|
|
+ * 2) The eBPF return value, arguments and callee-saved registers are mapped
|
|
+ * to their native MIPS equivalents.
|
|
+ * 3) Since the 32 highest bits in the eBPF FP register are always zero,
|
|
+ * only one general-purpose register is actually needed for the mapping.
|
|
+ * We use the fp register for this purpose, and map the highest bits to
|
|
+ * the MIPS register r0 (zero).
|
|
+ * 4) We use the MIPS gp and at registers as internal temporary registers
|
|
+ * for constant blinding. The gp register is callee-saved.
|
|
+ * 5) One 64-bit temporary register is mapped for use when sign-extending
|
|
+ * immediate operands. MIPS registers t6-t9 are available to the JIT
|
|
+ * for as temporaries when implementing complex 64-bit operations.
|
|
+ *
|
|
+ * With this scheme all eBPF registers are being mapped to native MIPS
|
|
+ * registers without having to use any stack scratch space. The direct
|
|
+ * register mapping (2) simplifies the handling of function calls.
|
|
+ */
|
|
+static const u8 bpf2mips32[][2] = {
|
|
+ /* Return value from in-kernel function, and exit value from eBPF */
|
|
+ [BPF_REG_0] = {MIPS_R_V1, MIPS_R_V0},
|
|
+ /* Arguments from eBPF program to in-kernel function */
|
|
+ [BPF_REG_1] = {MIPS_R_A1, MIPS_R_A0},
|
|
+ [BPF_REG_2] = {MIPS_R_A3, MIPS_R_A2},
|
|
+ /* Remaining arguments, to be passed on the stack per O32 ABI */
|
|
+ [BPF_REG_3] = {MIPS_R_T1, MIPS_R_T0},
|
|
+ [BPF_REG_4] = {MIPS_R_T3, MIPS_R_T2},
|
|
+ [BPF_REG_5] = {MIPS_R_T5, MIPS_R_T4},
|
|
+ /* Callee-saved registers that in-kernel function will preserve */
|
|
+ [BPF_REG_6] = {MIPS_R_S1, MIPS_R_S0},
|
|
+ [BPF_REG_7] = {MIPS_R_S3, MIPS_R_S2},
|
|
+ [BPF_REG_8] = {MIPS_R_S5, MIPS_R_S4},
|
|
+ [BPF_REG_9] = {MIPS_R_S7, MIPS_R_S6},
|
|
+ /* Read-only frame pointer to access the eBPF stack */
|
|
+#ifdef __BIG_ENDIAN
|
|
+ [BPF_REG_FP] = {MIPS_R_FP, MIPS_R_ZERO},
|
|
+#else
|
|
+ [BPF_REG_FP] = {MIPS_R_ZERO, MIPS_R_FP},
|
|
+#endif
|
|
+ /* Temporary register for blinding constants */
|
|
+ [BPF_REG_AX] = {MIPS_R_GP, MIPS_R_AT},
|
|
+ /* Temporary register for internal JIT use */
|
|
+ [JIT_REG_TMP] = {MIPS_R_T7, MIPS_R_T6},
|
|
+};
|
|
+
|
|
+/* Get low CPU register for a 64-bit eBPF register mapping */
|
|
+static inline u8 lo(const u8 reg[])
|
|
+{
|
|
+#ifdef __BIG_ENDIAN
|
|
+ return reg[0];
|
|
+#else
|
|
+ return reg[1];
|
|
+#endif
|
|
+}
|
|
+
|
|
+/* Get high CPU register for a 64-bit eBPF register mapping */
|
|
+static inline u8 hi(const u8 reg[])
|
|
+{
|
|
+#ifdef __BIG_ENDIAN
|
|
+ return reg[1];
|
|
+#else
|
|
+ return reg[0];
|
|
+#endif
|
|
+}
|
|
+
|
|
+/*
|
|
+ * Mark a 64-bit CPU register pair as clobbered, it needs to be
|
|
+ * saved/restored by the program if callee-saved.
|
|
+ */
|
|
+static void clobber_reg64(struct jit_context *ctx, const u8 reg[])
|
|
+{
|
|
+ clobber_reg(ctx, reg[0]);
|
|
+ clobber_reg(ctx, reg[1]);
|
|
+}
|
|
+
|
|
+/* dst = imm (sign-extended) */
|
|
+static void emit_mov_se_i64(struct jit_context *ctx, const u8 dst[], s32 imm)
|
|
+{
|
|
+ emit_mov_i(ctx, lo(dst), imm);
|
|
+ if (imm < 0)
|
|
+ emit(ctx, addiu, hi(dst), MIPS_R_ZERO, -1);
|
|
+ else
|
|
+ emit(ctx, move, hi(dst), MIPS_R_ZERO);
|
|
+ clobber_reg64(ctx, dst);
|
|
+}
|
|
+
|
|
+/* Zero extension, if verifier does not do it for us */
|
|
+static void emit_zext_ver(struct jit_context *ctx, const u8 dst[])
|
|
+{
|
|
+ if (!ctx->program->aux->verifier_zext) {
|
|
+ emit(ctx, move, hi(dst), MIPS_R_ZERO);
|
|
+ clobber_reg(ctx, hi(dst));
|
|
+ }
|
|
+}
|
|
+
|
|
+/* Load delay slot, if ISA mandates it */
|
|
+static void emit_load_delay(struct jit_context *ctx)
|
|
+{
|
|
+ if (!cpu_has_mips_2_3_4_5_r)
|
|
+ emit(ctx, nop);
|
|
+}
|
|
+
|
|
+/* ALU immediate operation (64-bit) */
|
|
+static void emit_alu_i64(struct jit_context *ctx,
|
|
+ const u8 dst[], s32 imm, u8 op)
|
|
+{
|
|
+ u8 src = MIPS_R_T6;
|
|
+
|
|
+ /*
|
|
+ * ADD/SUB with all but the max negative imm can be handled by
|
|
+ * inverting the operation and the imm value, saving one insn.
|
|
+ */
|
|
+ if (imm > S32_MIN && imm < 0)
|
|
+ switch (op) {
|
|
+ case BPF_ADD:
|
|
+ op = BPF_SUB;
|
|
+ imm = -imm;
|
|
+ break;
|
|
+ case BPF_SUB:
|
|
+ op = BPF_ADD;
|
|
+ imm = -imm;
|
|
+ break;
|
|
+ }
|
|
+
|
|
+ /* Move immediate to temporary register */
|
|
+ emit_mov_i(ctx, src, imm);
|
|
+
|
|
+ switch (op) {
|
|
+ /* dst = dst + imm */
|
|
+ case BPF_ADD:
|
|
+ emit(ctx, addu, lo(dst), lo(dst), src);
|
|
+ emit(ctx, sltu, MIPS_R_T9, lo(dst), src);
|
|
+ emit(ctx, addu, hi(dst), hi(dst), MIPS_R_T9);
|
|
+ if (imm < 0)
|
|
+ emit(ctx, addiu, hi(dst), hi(dst), -1);
|
|
+ break;
|
|
+ /* dst = dst - imm */
|
|
+ case BPF_SUB:
|
|
+ emit(ctx, sltu, MIPS_R_T9, lo(dst), src);
|
|
+ emit(ctx, subu, lo(dst), lo(dst), src);
|
|
+ emit(ctx, subu, hi(dst), hi(dst), MIPS_R_T9);
|
|
+ if (imm < 0)
|
|
+ emit(ctx, addiu, hi(dst), hi(dst), 1);
|
|
+ break;
|
|
+ /* dst = dst | imm */
|
|
+ case BPF_OR:
|
|
+ emit(ctx, or, lo(dst), lo(dst), src);
|
|
+ if (imm < 0)
|
|
+ emit(ctx, addiu, hi(dst), MIPS_R_ZERO, -1);
|
|
+ break;
|
|
+ /* dst = dst & imm */
|
|
+ case BPF_AND:
|
|
+ emit(ctx, and, lo(dst), lo(dst), src);
|
|
+ if (imm >= 0)
|
|
+ emit(ctx, move, hi(dst), MIPS_R_ZERO);
|
|
+ break;
|
|
+ /* dst = dst ^ imm */
|
|
+ case BPF_XOR:
|
|
+ emit(ctx, xor, lo(dst), lo(dst), src);
|
|
+ if (imm < 0) {
|
|
+ emit(ctx, subu, hi(dst), MIPS_R_ZERO, hi(dst));
|
|
+ emit(ctx, addiu, hi(dst), hi(dst), -1);
|
|
+ }
|
|
+ break;
|
|
+ }
|
|
+ clobber_reg64(ctx, dst);
|
|
+}
|
|
+
|
|
+/* ALU register operation (64-bit) */
|
|
+static void emit_alu_r64(struct jit_context *ctx,
|
|
+ const u8 dst[], const u8 src[], u8 op)
|
|
+{
|
|
+ switch (BPF_OP(op)) {
|
|
+ /* dst = dst + src */
|
|
+ case BPF_ADD:
|
|
+ if (src == dst) {
|
|
+ emit(ctx, srl, MIPS_R_T9, lo(dst), 31);
|
|
+ emit(ctx, addu, lo(dst), lo(dst), lo(dst));
|
|
+ } else {
|
|
+ emit(ctx, addu, lo(dst), lo(dst), lo(src));
|
|
+ emit(ctx, sltu, MIPS_R_T9, lo(dst), lo(src));
|
|
+ }
|
|
+ emit(ctx, addu, hi(dst), hi(dst), hi(src));
|
|
+ emit(ctx, addu, hi(dst), hi(dst), MIPS_R_T9);
|
|
+ break;
|
|
+ /* dst = dst - src */
|
|
+ case BPF_SUB:
|
|
+ emit(ctx, sltu, MIPS_R_T9, lo(dst), lo(src));
|
|
+ emit(ctx, subu, lo(dst), lo(dst), lo(src));
|
|
+ emit(ctx, subu, hi(dst), hi(dst), hi(src));
|
|
+ emit(ctx, subu, hi(dst), hi(dst), MIPS_R_T9);
|
|
+ break;
|
|
+ /* dst = dst | src */
|
|
+ case BPF_OR:
|
|
+ emit(ctx, or, lo(dst), lo(dst), lo(src));
|
|
+ emit(ctx, or, hi(dst), hi(dst), hi(src));
|
|
+ break;
|
|
+ /* dst = dst & src */
|
|
+ case BPF_AND:
|
|
+ emit(ctx, and, lo(dst), lo(dst), lo(src));
|
|
+ emit(ctx, and, hi(dst), hi(dst), hi(src));
|
|
+ break;
|
|
+ /* dst = dst ^ src */
|
|
+ case BPF_XOR:
|
|
+ emit(ctx, xor, lo(dst), lo(dst), lo(src));
|
|
+ emit(ctx, xor, hi(dst), hi(dst), hi(src));
|
|
+ break;
|
|
+ }
|
|
+ clobber_reg64(ctx, dst);
|
|
+}
|
|
+
|
|
+/* ALU invert (64-bit) */
|
|
+static void emit_neg_i64(struct jit_context *ctx, const u8 dst[])
|
|
+{
|
|
+ emit(ctx, sltu, MIPS_R_T9, MIPS_R_ZERO, lo(dst));
|
|
+ emit(ctx, subu, lo(dst), MIPS_R_ZERO, lo(dst));
|
|
+ emit(ctx, subu, hi(dst), MIPS_R_ZERO, hi(dst));
|
|
+ emit(ctx, subu, hi(dst), hi(dst), MIPS_R_T9);
|
|
+
|
|
+ clobber_reg64(ctx, dst);
|
|
+}
|
|
+
|
|
+/* ALU shift immediate (64-bit) */
|
|
+static void emit_shift_i64(struct jit_context *ctx,
|
|
+ const u8 dst[], u32 imm, u8 op)
|
|
+{
|
|
+ switch (BPF_OP(op)) {
|
|
+ /* dst = dst << imm */
|
|
+ case BPF_LSH:
|
|
+ if (imm < 32) {
|
|
+ emit(ctx, srl, MIPS_R_T9, lo(dst), 32 - imm);
|
|
+ emit(ctx, sll, lo(dst), lo(dst), imm);
|
|
+ emit(ctx, sll, hi(dst), hi(dst), imm);
|
|
+ emit(ctx, or, hi(dst), hi(dst), MIPS_R_T9);
|
|
+ } else {
|
|
+ emit(ctx, sll, hi(dst), lo(dst), imm - 32);
|
|
+ emit(ctx, move, lo(dst), MIPS_R_ZERO);
|
|
+ }
|
|
+ break;
|
|
+ /* dst = dst >> imm */
|
|
+ case BPF_RSH:
|
|
+ if (imm < 32) {
|
|
+ emit(ctx, sll, MIPS_R_T9, hi(dst), 32 - imm);
|
|
+ emit(ctx, srl, lo(dst), lo(dst), imm);
|
|
+ emit(ctx, srl, hi(dst), hi(dst), imm);
|
|
+ emit(ctx, or, lo(dst), lo(dst), MIPS_R_T9);
|
|
+ } else {
|
|
+ emit(ctx, srl, lo(dst), hi(dst), imm - 32);
|
|
+ emit(ctx, move, hi(dst), MIPS_R_ZERO);
|
|
+ }
|
|
+ break;
|
|
+ /* dst = dst >> imm (arithmetic) */
|
|
+ case BPF_ARSH:
|
|
+ if (imm < 32) {
|
|
+ emit(ctx, sll, MIPS_R_T9, hi(dst), 32 - imm);
|
|
+ emit(ctx, srl, lo(dst), lo(dst), imm);
|
|
+ emit(ctx, sra, hi(dst), hi(dst), imm);
|
|
+ emit(ctx, or, lo(dst), lo(dst), MIPS_R_T9);
|
|
+ } else {
|
|
+ emit(ctx, sra, lo(dst), hi(dst), imm - 32);
|
|
+ emit(ctx, sra, hi(dst), hi(dst), 31);
|
|
+ }
|
|
+ break;
|
|
+ }
|
|
+ clobber_reg64(ctx, dst);
|
|
+}
|
|
+
|
|
+/* ALU shift register (64-bit) */
|
|
+static void emit_shift_r64(struct jit_context *ctx,
|
|
+ const u8 dst[], u8 src, u8 op)
|
|
+{
|
|
+ u8 t1 = MIPS_R_T8;
|
|
+ u8 t2 = MIPS_R_T9;
|
|
+
|
|
+ emit(ctx, andi, t1, src, 32); /* t1 = src & 32 */
|
|
+ emit(ctx, beqz, t1, 16); /* PC += 16 if t1 == 0 */
|
|
+ emit(ctx, nor, t2, src, MIPS_R_ZERO); /* t2 = ~src (delay slot) */
|
|
+
|
|
+ switch (BPF_OP(op)) {
|
|
+ /* dst = dst << src */
|
|
+ case BPF_LSH:
|
|
+ /* Next: shift >= 32 */
|
|
+ emit(ctx, sllv, hi(dst), lo(dst), src); /* dh = dl << src */
|
|
+ emit(ctx, move, lo(dst), MIPS_R_ZERO); /* dl = 0 */
|
|
+ emit(ctx, b, 20); /* PC += 20 */
|
|
+ /* +16: shift < 32 */
|
|
+ emit(ctx, srl, t1, lo(dst), 1); /* t1 = dl >> 1 */
|
|
+ emit(ctx, srlv, t1, t1, t2); /* t1 = t1 >> t2 */
|
|
+ emit(ctx, sllv, lo(dst), lo(dst), src); /* dl = dl << src */
|
|
+ emit(ctx, sllv, hi(dst), hi(dst), src); /* dh = dh << src */
|
|
+ emit(ctx, or, hi(dst), hi(dst), t1); /* dh = dh | t1 */
|
|
+ break;
|
|
+ /* dst = dst >> src */
|
|
+ case BPF_RSH:
|
|
+ /* Next: shift >= 32 */
|
|
+ emit(ctx, srlv, lo(dst), hi(dst), src); /* dl = dh >> src */
|
|
+ emit(ctx, move, hi(dst), MIPS_R_ZERO); /* dh = 0 */
|
|
+ emit(ctx, b, 20); /* PC += 20 */
|
|
+ /* +16: shift < 32 */
|
|
+ emit(ctx, sll, t1, hi(dst), 1); /* t1 = dl << 1 */
|
|
+ emit(ctx, sllv, t1, t1, t2); /* t1 = t1 << t2 */
|
|
+ emit(ctx, srlv, lo(dst), lo(dst), src); /* dl = dl >> src */
|
|
+ emit(ctx, srlv, hi(dst), hi(dst), src); /* dh = dh >> src */
|
|
+ emit(ctx, or, lo(dst), lo(dst), t1); /* dl = dl | t1 */
|
|
+ break;
|
|
+ /* dst = dst >> src (arithmetic) */
|
|
+ case BPF_ARSH:
|
|
+ /* Next: shift >= 32 */
|
|
+ emit(ctx, srav, lo(dst), hi(dst), src); /* dl = dh >>a src */
|
|
+ emit(ctx, sra, hi(dst), hi(dst), 31); /* dh = dh >>a 31 */
|
|
+ emit(ctx, b, 20); /* PC += 20 */
|
|
+ /* +16: shift < 32 */
|
|
+ emit(ctx, sll, t1, hi(dst), 1); /* t1 = dl << 1 */
|
|
+ emit(ctx, sllv, t1, t1, t2); /* t1 = t1 << t2 */
|
|
+ emit(ctx, srlv, lo(dst), lo(dst), src); /* dl = dl >>a src */
|
|
+ emit(ctx, srav, hi(dst), hi(dst), src); /* dh = dh >> src */
|
|
+ emit(ctx, or, lo(dst), lo(dst), t1); /* dl = dl | t1 */
|
|
+ break;
|
|
+ }
|
|
+
|
|
+ /* +20: Done */
|
|
+ clobber_reg64(ctx, dst);
|
|
+}
|
|
+
|
|
+/* ALU mul immediate (64x32-bit) */
|
|
+static void emit_mul_i64(struct jit_context *ctx, const u8 dst[], s32 imm)
|
|
+{
|
|
+ u8 src = MIPS_R_T6;
|
|
+ u8 tmp = MIPS_R_T9;
|
|
+
|
|
+ switch (imm) {
|
|
+ /* dst = dst * 1 is a no-op */
|
|
+ case 1:
|
|
+ break;
|
|
+ /* dst = dst * -1 */
|
|
+ case -1:
|
|
+ emit_neg_i64(ctx, dst);
|
|
+ break;
|
|
+ case 0:
|
|
+ emit_mov_r(ctx, lo(dst), MIPS_R_ZERO);
|
|
+ emit_mov_r(ctx, hi(dst), MIPS_R_ZERO);
|
|
+ break;
|
|
+ /* Full 64x32 multiply */
|
|
+ default:
|
|
+ /* hi(dst) = hi(dst) * src(imm) */
|
|
+ emit_mov_i(ctx, src, imm);
|
|
+ if (cpu_has_mips32r1 || cpu_has_mips32r6) {
|
|
+ emit(ctx, mul, hi(dst), hi(dst), src);
|
|
+ } else {
|
|
+ emit(ctx, multu, hi(dst), src);
|
|
+ emit(ctx, mflo, hi(dst));
|
|
+ }
|
|
+
|
|
+ /* hi(dst) = hi(dst) - lo(dst) */
|
|
+ if (imm < 0)
|
|
+ emit(ctx, subu, hi(dst), hi(dst), lo(dst));
|
|
+
|
|
+ /* tmp = lo(dst) * src(imm) >> 32 */
|
|
+ /* lo(dst) = lo(dst) * src(imm) */
|
|
+ if (cpu_has_mips32r6) {
|
|
+ emit(ctx, muhu, tmp, lo(dst), src);
|
|
+ emit(ctx, mulu, lo(dst), lo(dst), src);
|
|
+ } else {
|
|
+ emit(ctx, multu, lo(dst), src);
|
|
+ emit(ctx, mflo, lo(dst));
|
|
+ emit(ctx, mfhi, tmp);
|
|
+ }
|
|
+
|
|
+ /* hi(dst) += tmp */
|
|
+ emit(ctx, addu, hi(dst), hi(dst), tmp);
|
|
+ clobber_reg64(ctx, dst);
|
|
+ break;
|
|
+ }
|
|
+}
|
|
+
|
|
+/* ALU mul register (64x64-bit) */
|
|
+static void emit_mul_r64(struct jit_context *ctx,
|
|
+ const u8 dst[], const u8 src[])
|
|
+{
|
|
+ u8 acc = MIPS_R_T8;
|
|
+ u8 tmp = MIPS_R_T9;
|
|
+
|
|
+ /* acc = hi(dst) * lo(src) */
|
|
+ if (cpu_has_mips32r1 || cpu_has_mips32r6) {
|
|
+ emit(ctx, mul, acc, hi(dst), lo(src));
|
|
+ } else {
|
|
+ emit(ctx, multu, hi(dst), lo(src));
|
|
+ emit(ctx, mflo, acc);
|
|
+ }
|
|
+
|
|
+ /* tmp = lo(dst) * hi(src) */
|
|
+ if (cpu_has_mips32r1 || cpu_has_mips32r6) {
|
|
+ emit(ctx, mul, tmp, lo(dst), hi(src));
|
|
+ } else {
|
|
+ emit(ctx, multu, lo(dst), hi(src));
|
|
+ emit(ctx, mflo, tmp);
|
|
+ }
|
|
+
|
|
+ /* acc += tmp */
|
|
+ emit(ctx, addu, acc, acc, tmp);
|
|
+
|
|
+ /* tmp = lo(dst) * lo(src) >> 32 */
|
|
+ /* lo(dst) = lo(dst) * lo(src) */
|
|
+ if (cpu_has_mips32r6) {
|
|
+ emit(ctx, muhu, tmp, lo(dst), lo(src));
|
|
+ emit(ctx, mulu, lo(dst), lo(dst), lo(src));
|
|
+ } else {
|
|
+ emit(ctx, multu, lo(dst), lo(src));
|
|
+ emit(ctx, mflo, lo(dst));
|
|
+ emit(ctx, mfhi, tmp);
|
|
+ }
|
|
+
|
|
+ /* hi(dst) = acc + tmp */
|
|
+ emit(ctx, addu, hi(dst), acc, tmp);
|
|
+ clobber_reg64(ctx, dst);
|
|
+}
|
|
+
|
|
+/* Helper function for 64-bit modulo */
|
|
+static u64 jit_mod64(u64 a, u64 b)
|
|
+{
|
|
+ u64 rem;
|
|
+
|
|
+ div64_u64_rem(a, b, &rem);
|
|
+ return rem;
|
|
+}
|
|
+
|
|
+/* ALU div/mod register (64-bit) */
|
|
+static void emit_divmod_r64(struct jit_context *ctx,
|
|
+ const u8 dst[], const u8 src[], u8 op)
|
|
+{
|
|
+ const u8 *r0 = bpf2mips32[BPF_REG_0]; /* Mapped to v0-v1 */
|
|
+ const u8 *r1 = bpf2mips32[BPF_REG_1]; /* Mapped to a0-a1 */
|
|
+ const u8 *r2 = bpf2mips32[BPF_REG_2]; /* Mapped to a2-a3 */
|
|
+ int exclude, k;
|
|
+ u32 addr = 0;
|
|
+
|
|
+ /* Push caller-saved registers on stack */
|
|
+ push_regs(ctx, ctx->clobbered & JIT_CALLER_REGS,
|
|
+ 0, JIT_RESERVED_STACK);
|
|
+
|
|
+ /* Put 64-bit arguments 1 and 2 in registers a0-a3 */
|
|
+ for (k = 0; k < 2; k++) {
|
|
+ emit(ctx, move, MIPS_R_T9, src[k]);
|
|
+ emit(ctx, move, r1[k], dst[k]);
|
|
+ emit(ctx, move, r2[k], MIPS_R_T9);
|
|
+ }
|
|
+
|
|
+ /* Emit function call */
|
|
+ switch (BPF_OP(op)) {
|
|
+ /* dst = dst / src */
|
|
+ case BPF_DIV:
|
|
+ addr = (u32)&div64_u64;
|
|
+ break;
|
|
+ /* dst = dst % src */
|
|
+ case BPF_MOD:
|
|
+ addr = (u32)&jit_mod64;
|
|
+ break;
|
|
+ }
|
|
+ emit_mov_i(ctx, MIPS_R_T9, addr);
|
|
+ emit(ctx, jalr, MIPS_R_RA, MIPS_R_T9);
|
|
+ emit(ctx, nop); /* Delay slot */
|
|
+
|
|
+ /* Store the 64-bit result in dst */
|
|
+ emit(ctx, move, dst[0], r0[0]);
|
|
+ emit(ctx, move, dst[1], r0[1]);
|
|
+
|
|
+ /* Restore caller-saved registers, excluding the computed result */
|
|
+ exclude = BIT(lo(dst)) | BIT(hi(dst));
|
|
+ pop_regs(ctx, ctx->clobbered & JIT_CALLER_REGS,
|
|
+ exclude, JIT_RESERVED_STACK);
|
|
+ emit_load_delay(ctx);
|
|
+
|
|
+ clobber_reg64(ctx, dst);
|
|
+ clobber_reg(ctx, MIPS_R_V0);
|
|
+ clobber_reg(ctx, MIPS_R_V1);
|
|
+ clobber_reg(ctx, MIPS_R_RA);
|
|
+}
|
|
+
|
|
+/* Swap bytes in a register word */
|
|
+static void emit_swap8_r(struct jit_context *ctx, u8 dst, u8 src, u8 mask)
|
|
+{
|
|
+ u8 tmp = MIPS_R_T9;
|
|
+
|
|
+ emit(ctx, and, tmp, src, mask); /* tmp = src & 0x00ff00ff */
|
|
+ emit(ctx, sll, tmp, tmp, 8); /* tmp = tmp << 8 */
|
|
+ emit(ctx, srl, dst, src, 8); /* dst = src >> 8 */
|
|
+ emit(ctx, and, dst, dst, mask); /* dst = dst & 0x00ff00ff */
|
|
+ emit(ctx, or, dst, dst, tmp); /* dst = dst | tmp */
|
|
+}
|
|
+
|
|
+/* Swap half words in a register word */
|
|
+static void emit_swap16_r(struct jit_context *ctx, u8 dst, u8 src)
|
|
+{
|
|
+ u8 tmp = MIPS_R_T9;
|
|
+
|
|
+ emit(ctx, sll, tmp, src, 16); /* tmp = src << 16 */
|
|
+ emit(ctx, srl, dst, src, 16); /* dst = src >> 16 */
|
|
+ emit(ctx, or, dst, dst, tmp); /* dst = dst | tmp */
|
|
+}
|
|
+
|
|
+/* Swap bytes and truncate a register double word, word or half word */
|
|
+static void emit_bswap_r64(struct jit_context *ctx, const u8 dst[], u32 width)
|
|
+{
|
|
+ u8 tmp = MIPS_R_T8;
|
|
+
|
|
+ switch (width) {
|
|
+ /* Swap bytes in a double word */
|
|
+ case 64:
|
|
+ if (cpu_has_mips32r2 || cpu_has_mips32r6) {
|
|
+ emit(ctx, rotr, tmp, hi(dst), 16);
|
|
+ emit(ctx, rotr, hi(dst), lo(dst), 16);
|
|
+ emit(ctx, wsbh, lo(dst), tmp);
|
|
+ emit(ctx, wsbh, hi(dst), hi(dst));
|
|
+ } else {
|
|
+ emit_swap16_r(ctx, tmp, lo(dst));
|
|
+ emit_swap16_r(ctx, lo(dst), hi(dst));
|
|
+ emit(ctx, move, hi(dst), tmp);
|
|
+
|
|
+ emit(ctx, lui, tmp, 0xff); /* tmp = 0x00ff0000 */
|
|
+ emit(ctx, ori, tmp, tmp, 0xff); /* tmp = 0x00ff00ff */
|
|
+ emit_swap8_r(ctx, lo(dst), lo(dst), tmp);
|
|
+ emit_swap8_r(ctx, hi(dst), hi(dst), tmp);
|
|
+ }
|
|
+ break;
|
|
+ /* Swap bytes in a word */
|
|
+ /* Swap bytes in a half word */
|
|
+ case 32:
|
|
+ case 16:
|
|
+ emit_bswap_r(ctx, lo(dst), width);
|
|
+ emit(ctx, move, hi(dst), MIPS_R_ZERO);
|
|
+ break;
|
|
+ }
|
|
+ clobber_reg64(ctx, dst);
|
|
+}
|
|
+
|
|
+/* Truncate a register double word, word or half word */
|
|
+static void emit_trunc_r64(struct jit_context *ctx, const u8 dst[], u32 width)
|
|
+{
|
|
+ switch (width) {
|
|
+ case 64:
|
|
+ break;
|
|
+ /* Zero-extend a word */
|
|
+ case 32:
|
|
+ emit(ctx, move, hi(dst), MIPS_R_ZERO);
|
|
+ clobber_reg(ctx, hi(dst));
|
|
+ break;
|
|
+ /* Zero-extend a half word */
|
|
+ case 16:
|
|
+ emit(ctx, move, hi(dst), MIPS_R_ZERO);
|
|
+ emit(ctx, andi, lo(dst), lo(dst), 0xffff);
|
|
+ clobber_reg64(ctx, dst);
|
|
+ break;
|
|
+ }
|
|
+}
|
|
+
|
|
+/* Load operation: dst = *(size*)(src + off) */
|
|
+static void emit_ldx(struct jit_context *ctx,
|
|
+ const u8 dst[], u8 src, s16 off, u8 size)
|
|
+{
|
|
+ switch (size) {
|
|
+ /* Load a byte */
|
|
+ case BPF_B:
|
|
+ emit(ctx, lbu, lo(dst), off, src);
|
|
+ emit(ctx, move, hi(dst), MIPS_R_ZERO);
|
|
+ break;
|
|
+ /* Load a half word */
|
|
+ case BPF_H:
|
|
+ emit(ctx, lhu, lo(dst), off, src);
|
|
+ emit(ctx, move, hi(dst), MIPS_R_ZERO);
|
|
+ break;
|
|
+ /* Load a word */
|
|
+ case BPF_W:
|
|
+ emit(ctx, lw, lo(dst), off, src);
|
|
+ emit(ctx, move, hi(dst), MIPS_R_ZERO);
|
|
+ break;
|
|
+ /* Load a double word */
|
|
+ case BPF_DW:
|
|
+ if (dst[1] == src) {
|
|
+ emit(ctx, lw, dst[0], off + 4, src);
|
|
+ emit(ctx, lw, dst[1], off, src);
|
|
+ } else {
|
|
+ emit(ctx, lw, dst[1], off, src);
|
|
+ emit(ctx, lw, dst[0], off + 4, src);
|
|
+ }
|
|
+ emit_load_delay(ctx);
|
|
+ break;
|
|
+ }
|
|
+ clobber_reg64(ctx, dst);
|
|
+}
|
|
+
|
|
+/* Store operation: *(size *)(dst + off) = src */
|
|
+static void emit_stx(struct jit_context *ctx,
|
|
+ const u8 dst, const u8 src[], s16 off, u8 size)
|
|
+{
|
|
+ switch (size) {
|
|
+ /* Store a byte */
|
|
+ case BPF_B:
|
|
+ emit(ctx, sb, lo(src), off, dst);
|
|
+ break;
|
|
+ /* Store a half word */
|
|
+ case BPF_H:
|
|
+ emit(ctx, sh, lo(src), off, dst);
|
|
+ break;
|
|
+ /* Store a word */
|
|
+ case BPF_W:
|
|
+ emit(ctx, sw, lo(src), off, dst);
|
|
+ break;
|
|
+ /* Store a double word */
|
|
+ case BPF_DW:
|
|
+ emit(ctx, sw, src[1], off, dst);
|
|
+ emit(ctx, sw, src[0], off + 4, dst);
|
|
+ break;
|
|
+ }
|
|
+}
|
|
+
|
|
+/* Atomic read-modify-write (32-bit, non-ll/sc fallback) */
|
|
+static void emit_atomic_r32(struct jit_context *ctx,
|
|
+ u8 dst, u8 src, s16 off, u8 code)
|
|
+{
|
|
+ u32 exclude = 0;
|
|
+ u32 addr = 0;
|
|
+
|
|
+ /* Push caller-saved registers on stack */
|
|
+ push_regs(ctx, ctx->clobbered & JIT_CALLER_REGS,
|
|
+ 0, JIT_RESERVED_STACK);
|
|
+ /*
|
|
+ * Argument 1: dst+off if xchg, otherwise src, passed in register a0
|
|
+ * Argument 2: src if xchg, othersize dst+off, passed in register a1
|
|
+ */
|
|
+ emit(ctx, move, MIPS_R_T9, dst);
|
|
+ emit(ctx, move, MIPS_R_A0, src);
|
|
+ emit(ctx, addiu, MIPS_R_A1, MIPS_R_T9, off);
|
|
+
|
|
+ /* Emit function call */
|
|
+ switch (code) {
|
|
+ case BPF_ADD:
|
|
+ addr = (u32)&atomic_add;
|
|
+ break;
|
|
+ case BPF_SUB:
|
|
+ addr = (u32)&atomic_sub;
|
|
+ break;
|
|
+ case BPF_OR:
|
|
+ addr = (u32)&atomic_or;
|
|
+ break;
|
|
+ case BPF_AND:
|
|
+ addr = (u32)&atomic_and;
|
|
+ break;
|
|
+ case BPF_XOR:
|
|
+ addr = (u32)&atomic_xor;
|
|
+ break;
|
|
+ }
|
|
+ emit_mov_i(ctx, MIPS_R_T9, addr);
|
|
+ emit(ctx, jalr, MIPS_R_RA, MIPS_R_T9);
|
|
+ emit(ctx, nop); /* Delay slot */
|
|
+
|
|
+ /* Restore caller-saved registers, except any fetched value */
|
|
+ pop_regs(ctx, ctx->clobbered & JIT_CALLER_REGS,
|
|
+ exclude, JIT_RESERVED_STACK);
|
|
+ emit_load_delay(ctx);
|
|
+ clobber_reg(ctx, MIPS_R_RA);
|
|
+}
|
|
+
|
|
+/* Atomic read-modify-write (64-bit) */
|
|
+static void emit_atomic_r64(struct jit_context *ctx,
|
|
+ u8 dst, const u8 src[], s16 off, u8 code)
|
|
+{
|
|
+ const u8 *r1 = bpf2mips32[BPF_REG_1]; /* Mapped to a0-a1 */
|
|
+ u32 exclude = 0;
|
|
+ u32 addr = 0;
|
|
+
|
|
+ /* Push caller-saved registers on stack */
|
|
+ push_regs(ctx, ctx->clobbered & JIT_CALLER_REGS,
|
|
+ 0, JIT_RESERVED_STACK);
|
|
+ /*
|
|
+ * Argument 1: 64-bit src, passed in registers a0-a1
|
|
+ * Argument 2: 32-bit dst+off, passed in register a2
|
|
+ */
|
|
+ emit(ctx, move, MIPS_R_T9, dst);
|
|
+ emit(ctx, move, r1[0], src[0]);
|
|
+ emit(ctx, move, r1[1], src[1]);
|
|
+ emit(ctx, addiu, MIPS_R_A2, MIPS_R_T9, off);
|
|
+
|
|
+ /* Emit function call */
|
|
+ switch (code) {
|
|
+ case BPF_ADD:
|
|
+ addr = (u32)&atomic64_add;
|
|
+ break;
|
|
+ case BPF_SUB:
|
|
+ addr = (u32)&atomic64_sub;
|
|
+ break;
|
|
+ case BPF_OR:
|
|
+ addr = (u32)&atomic64_or;
|
|
+ break;
|
|
+ case BPF_AND:
|
|
+ addr = (u32)&atomic64_and;
|
|
+ break;
|
|
+ case BPF_XOR:
|
|
+ addr = (u32)&atomic64_xor;
|
|
+ break;
|
|
+ }
|
|
+ emit_mov_i(ctx, MIPS_R_T9, addr);
|
|
+ emit(ctx, jalr, MIPS_R_RA, MIPS_R_T9);
|
|
+ emit(ctx, nop); /* Delay slot */
|
|
+
|
|
+ /* Restore caller-saved registers, except any fetched value */
|
|
+ pop_regs(ctx, ctx->clobbered & JIT_CALLER_REGS,
|
|
+ exclude, JIT_RESERVED_STACK);
|
|
+ emit_load_delay(ctx);
|
|
+ clobber_reg(ctx, MIPS_R_RA);
|
|
+}
|
|
+
|
|
+/*
|
|
+ * Conditional movz or an emulated equivalent.
|
|
+ * Note that the rs register may be modified.
|
|
+ */
|
|
+static void emit_movz_r(struct jit_context *ctx, u8 rd, u8 rs, u8 rt)
|
|
+{
|
|
+ if (cpu_has_mips_2) {
|
|
+ emit(ctx, movz, rd, rs, rt); /* rd = rt ? rd : rs */
|
|
+ } else if (cpu_has_mips32r6) {
|
|
+ if (rs != MIPS_R_ZERO)
|
|
+ emit(ctx, seleqz, rs, rs, rt); /* rs = 0 if rt == 0 */
|
|
+ emit(ctx, selnez, rd, rd, rt); /* rd = 0 if rt != 0 */
|
|
+ if (rs != MIPS_R_ZERO)
|
|
+ emit(ctx, or, rd, rd, rs); /* rd = rd | rs */
|
|
+ } else {
|
|
+ emit(ctx, bnez, rt, 8); /* PC += 8 if rd != 0 */
|
|
+ emit(ctx, nop); /* +0: delay slot */
|
|
+ emit(ctx, or, rd, rs, MIPS_R_ZERO); /* +4: rd = rs */
|
|
+ }
|
|
+ clobber_reg(ctx, rd);
|
|
+ clobber_reg(ctx, rs);
|
|
+}
|
|
+
|
|
+/*
|
|
+ * Conditional movn or an emulated equivalent.
|
|
+ * Note that the rs register may be modified.
|
|
+ */
|
|
+static void emit_movn_r(struct jit_context *ctx, u8 rd, u8 rs, u8 rt)
|
|
+{
|
|
+ if (cpu_has_mips_2) {
|
|
+ emit(ctx, movn, rd, rs, rt); /* rd = rt ? rs : rd */
|
|
+ } else if (cpu_has_mips32r6) {
|
|
+ if (rs != MIPS_R_ZERO)
|
|
+ emit(ctx, selnez, rs, rs, rt); /* rs = 0 if rt == 0 */
|
|
+ emit(ctx, seleqz, rd, rd, rt); /* rd = 0 if rt != 0 */
|
|
+ if (rs != MIPS_R_ZERO)
|
|
+ emit(ctx, or, rd, rd, rs); /* rd = rd | rs */
|
|
+ } else {
|
|
+ emit(ctx, beqz, rt, 8); /* PC += 8 if rd == 0 */
|
|
+ emit(ctx, nop); /* +0: delay slot */
|
|
+ emit(ctx, or, rd, rs, MIPS_R_ZERO); /* +4: rd = rs */
|
|
+ }
|
|
+ clobber_reg(ctx, rd);
|
|
+ clobber_reg(ctx, rs);
|
|
+}
|
|
+
|
|
+/* Emulation of 64-bit sltiu rd, rs, imm, where imm may be S32_MAX + 1 */
|
|
+static void emit_sltiu_r64(struct jit_context *ctx, u8 rd,
|
|
+ const u8 rs[], s64 imm)
|
|
+{
|
|
+ u8 tmp = MIPS_R_T9;
|
|
+
|
|
+ if (imm < 0) {
|
|
+ emit_mov_i(ctx, rd, imm); /* rd = imm */
|
|
+ emit(ctx, sltu, rd, lo(rs), rd); /* rd = rsl < rd */
|
|
+ emit(ctx, sltiu, tmp, hi(rs), -1); /* tmp = rsh < ~0U */
|
|
+ emit(ctx, or, rd, rd, tmp); /* rd = rd | tmp */
|
|
+ } else { /* imm >= 0 */
|
|
+ if (imm > 0x7fff) {
|
|
+ emit_mov_i(ctx, rd, (s32)imm); /* rd = imm */
|
|
+ emit(ctx, sltu, rd, lo(rs), rd); /* rd = rsl < rd */
|
|
+ } else {
|
|
+ emit(ctx, sltiu, rd, lo(rs), imm); /* rd = rsl < imm */
|
|
+ }
|
|
+ emit_movn_r(ctx, rd, MIPS_R_ZERO, hi(rs)); /* rd = 0 if rsh */
|
|
+ }
|
|
+}
|
|
+
|
|
+/* Emulation of 64-bit sltu rd, rs, rt */
|
|
+static void emit_sltu_r64(struct jit_context *ctx, u8 rd,
|
|
+ const u8 rs[], const u8 rt[])
|
|
+{
|
|
+ u8 tmp = MIPS_R_T9;
|
|
+
|
|
+ emit(ctx, sltu, rd, lo(rs), lo(rt)); /* rd = rsl < rtl */
|
|
+ emit(ctx, subu, tmp, hi(rs), hi(rt)); /* tmp = rsh - rth */
|
|
+ emit_movn_r(ctx, rd, MIPS_R_ZERO, tmp); /* rd = 0 if tmp != 0 */
|
|
+ emit(ctx, sltu, tmp, hi(rs), hi(rt)); /* tmp = rsh < rth */
|
|
+ emit(ctx, or, rd, rd, tmp); /* rd = rd | tmp */
|
|
+}
|
|
+
|
|
+/* Emulation of 64-bit slti rd, rs, imm, where imm may be S32_MAX + 1 */
|
|
+static void emit_slti_r64(struct jit_context *ctx, u8 rd,
|
|
+ const u8 rs[], s64 imm)
|
|
+{
|
|
+ u8 t1 = MIPS_R_T8;
|
|
+ u8 t2 = MIPS_R_T9;
|
|
+ u8 cmp;
|
|
+
|
|
+ /*
|
|
+ * if ((rs < 0) ^ (imm < 0)) t1 = imm >u rsl
|
|
+ * else t1 = rsl <u imm
|
|
+ */
|
|
+ emit_mov_i(ctx, rd, (s32)imm);
|
|
+ emit(ctx, sltu, t1, lo(rs), rd); /* t1 = rsl <u imm */
|
|
+ emit(ctx, sltu, t2, rd, lo(rs)); /* t2 = imm <u rsl */
|
|
+ emit(ctx, srl, rd, hi(rs), 31); /* rd = rsh >> 31 */
|
|
+ if (imm < 0)
|
|
+ emit_movz_r(ctx, t1, t2, rd); /* t1 = rd ? t1 : t2 */
|
|
+ else
|
|
+ emit_movn_r(ctx, t1, t2, rd); /* t1 = rd ? t2 : t1 */
|
|
+ /*
|
|
+ * if ((imm < 0 && rsh != 0xffffffff) ||
|
|
+ * (imm >= 0 && rsh != 0))
|
|
+ * t1 = 0
|
|
+ */
|
|
+ if (imm < 0) {
|
|
+ emit(ctx, addiu, rd, hi(rs), 1); /* rd = rsh + 1 */
|
|
+ cmp = rd;
|
|
+ } else { /* imm >= 0 */
|
|
+ cmp = hi(rs);
|
|
+ }
|
|
+ emit_movn_r(ctx, t1, MIPS_R_ZERO, cmp); /* t1 = 0 if cmp != 0 */
|
|
+
|
|
+ /*
|
|
+ * if (imm < 0) rd = rsh < -1
|
|
+ * else rd = rsh != 0
|
|
+ * rd = rd | t1
|
|
+ */
|
|
+ emit(ctx, slti, rd, hi(rs), imm < 0 ? -1 : 0); /* rd = rsh < hi(imm) */
|
|
+ emit(ctx, or, rd, rd, t1); /* rd = rd | t1 */
|
|
+}
|
|
+
|
|
+/* Emulation of 64-bit(slt rd, rs, rt) */
|
|
+static void emit_slt_r64(struct jit_context *ctx, u8 rd,
|
|
+ const u8 rs[], const u8 rt[])
|
|
+{
|
|
+ u8 t1 = MIPS_R_T7;
|
|
+ u8 t2 = MIPS_R_T8;
|
|
+ u8 t3 = MIPS_R_T9;
|
|
+
|
|
+ /*
|
|
+ * if ((rs < 0) ^ (rt < 0)) t1 = rtl <u rsl
|
|
+ * else t1 = rsl <u rtl
|
|
+ * if (rsh == rth) t1 = 0
|
|
+ */
|
|
+ emit(ctx, sltu, t1, lo(rs), lo(rt)); /* t1 = rsl <u rtl */
|
|
+ emit(ctx, sltu, t2, lo(rt), lo(rs)); /* t2 = rtl <u rsl */
|
|
+ emit(ctx, xor, t3, hi(rs), hi(rt)); /* t3 = rlh ^ rth */
|
|
+ emit(ctx, srl, rd, t3, 31); /* rd = t3 >> 31 */
|
|
+ emit_movn_r(ctx, t1, t2, rd); /* t1 = rd ? t2 : t1 */
|
|
+ emit_movn_r(ctx, t1, MIPS_R_ZERO, t3); /* t1 = 0 if t3 != 0 */
|
|
+
|
|
+ /* rd = (rsh < rth) | t1 */
|
|
+ emit(ctx, slt, rd, hi(rs), hi(rt)); /* rd = rsh <s rth */
|
|
+ emit(ctx, or, rd, rd, t1); /* rd = rd | t1 */
|
|
+}
|
|
+
|
|
+/* Jump immediate (64-bit) */
|
|
+static void emit_jmp_i64(struct jit_context *ctx,
|
|
+ const u8 dst[], s32 imm, s32 off, u8 op)
|
|
+{
|
|
+ u8 tmp = MIPS_R_T6;
|
|
+
|
|
+ switch (op) {
|
|
+ /* No-op, used internally for branch optimization */
|
|
+ case JIT_JNOP:
|
|
+ break;
|
|
+ /* PC += off if dst == imm */
|
|
+ /* PC += off if dst != imm */
|
|
+ case BPF_JEQ:
|
|
+ case BPF_JNE:
|
|
+ if (imm >= -0x7fff && imm <= 0x8000) {
|
|
+ emit(ctx, addiu, tmp, lo(dst), -imm);
|
|
+ } else if ((u32)imm <= 0xffff) {
|
|
+ emit(ctx, xori, tmp, lo(dst), imm);
|
|
+ } else { /* Register fallback */
|
|
+ emit_mov_i(ctx, tmp, imm);
|
|
+ emit(ctx, xor, tmp, lo(dst), tmp);
|
|
+ }
|
|
+ if (imm < 0) { /* Compare sign extension */
|
|
+ emit(ctx, addu, MIPS_R_T9, hi(dst), 1);
|
|
+ emit(ctx, or, tmp, tmp, MIPS_R_T9);
|
|
+ } else { /* Compare zero extension */
|
|
+ emit(ctx, or, tmp, tmp, hi(dst));
|
|
+ }
|
|
+ if (op == BPF_JEQ)
|
|
+ emit(ctx, beqz, tmp, off);
|
|
+ else /* BPF_JNE */
|
|
+ emit(ctx, bnez, tmp, off);
|
|
+ break;
|
|
+ /* PC += off if dst & imm */
|
|
+ /* PC += off if (dst & imm) == 0 (not in BPF, used for long jumps) */
|
|
+ case BPF_JSET:
|
|
+ case JIT_JNSET:
|
|
+ if ((u32)imm <= 0xffff) {
|
|
+ emit(ctx, andi, tmp, lo(dst), imm);
|
|
+ } else { /* Register fallback */
|
|
+ emit_mov_i(ctx, tmp, imm);
|
|
+ emit(ctx, and, tmp, lo(dst), tmp);
|
|
+ }
|
|
+ if (imm < 0) /* Sign-extension pulls in high word */
|
|
+ emit(ctx, or, tmp, tmp, hi(dst));
|
|
+ if (op == BPF_JSET)
|
|
+ emit(ctx, bnez, tmp, off);
|
|
+ else /* JIT_JNSET */
|
|
+ emit(ctx, beqz, tmp, off);
|
|
+ break;
|
|
+ /* PC += off if dst > imm */
|
|
+ case BPF_JGT:
|
|
+ emit_sltiu_r64(ctx, tmp, dst, (s64)imm + 1);
|
|
+ emit(ctx, beqz, tmp, off);
|
|
+ break;
|
|
+ /* PC += off if dst >= imm */
|
|
+ case BPF_JGE:
|
|
+ emit_sltiu_r64(ctx, tmp, dst, imm);
|
|
+ emit(ctx, beqz, tmp, off);
|
|
+ break;
|
|
+ /* PC += off if dst < imm */
|
|
+ case BPF_JLT:
|
|
+ emit_sltiu_r64(ctx, tmp, dst, imm);
|
|
+ emit(ctx, bnez, tmp, off);
|
|
+ break;
|
|
+ /* PC += off if dst <= imm */
|
|
+ case BPF_JLE:
|
|
+ emit_sltiu_r64(ctx, tmp, dst, (s64)imm + 1);
|
|
+ emit(ctx, bnez, tmp, off);
|
|
+ break;
|
|
+ /* PC += off if dst > imm (signed) */
|
|
+ case BPF_JSGT:
|
|
+ emit_slti_r64(ctx, tmp, dst, (s64)imm + 1);
|
|
+ emit(ctx, beqz, tmp, off);
|
|
+ break;
|
|
+ /* PC += off if dst >= imm (signed) */
|
|
+ case BPF_JSGE:
|
|
+ emit_slti_r64(ctx, tmp, dst, imm);
|
|
+ emit(ctx, beqz, tmp, off);
|
|
+ break;
|
|
+ /* PC += off if dst < imm (signed) */
|
|
+ case BPF_JSLT:
|
|
+ emit_slti_r64(ctx, tmp, dst, imm);
|
|
+ emit(ctx, bnez, tmp, off);
|
|
+ break;
|
|
+ /* PC += off if dst <= imm (signed) */
|
|
+ case BPF_JSLE:
|
|
+ emit_slti_r64(ctx, tmp, dst, (s64)imm + 1);
|
|
+ emit(ctx, bnez, tmp, off);
|
|
+ break;
|
|
+ }
|
|
+}
|
|
+
|
|
+/* Jump register (64-bit) */
|
|
+static void emit_jmp_r64(struct jit_context *ctx,
|
|
+ const u8 dst[], const u8 src[], s32 off, u8 op)
|
|
+{
|
|
+ u8 t1 = MIPS_R_T6;
|
|
+ u8 t2 = MIPS_R_T7;
|
|
+
|
|
+ switch (op) {
|
|
+ /* No-op, used internally for branch optimization */
|
|
+ case JIT_JNOP:
|
|
+ break;
|
|
+ /* PC += off if dst == src */
|
|
+ /* PC += off if dst != src */
|
|
+ case BPF_JEQ:
|
|
+ case BPF_JNE:
|
|
+ emit(ctx, subu, t1, lo(dst), lo(src));
|
|
+ emit(ctx, subu, t2, hi(dst), hi(src));
|
|
+ emit(ctx, or, t1, t1, t2);
|
|
+ if (op == BPF_JEQ)
|
|
+ emit(ctx, beqz, t1, off);
|
|
+ else /* BPF_JNE */
|
|
+ emit(ctx, bnez, t1, off);
|
|
+ break;
|
|
+ /* PC += off if dst & src */
|
|
+ /* PC += off if (dst & imm) == 0 (not in BPF, used for long jumps) */
|
|
+ case BPF_JSET:
|
|
+ case JIT_JNSET:
|
|
+ emit(ctx, and, t1, lo(dst), lo(src));
|
|
+ emit(ctx, and, t2, hi(dst), hi(src));
|
|
+ emit(ctx, or, t1, t1, t2);
|
|
+ if (op == BPF_JSET)
|
|
+ emit(ctx, bnez, t1, off);
|
|
+ else /* JIT_JNSET */
|
|
+ emit(ctx, beqz, t1, off);
|
|
+ break;
|
|
+ /* PC += off if dst > src */
|
|
+ case BPF_JGT:
|
|
+ emit_sltu_r64(ctx, t1, src, dst);
|
|
+ emit(ctx, bnez, t1, off);
|
|
+ break;
|
|
+ /* PC += off if dst >= src */
|
|
+ case BPF_JGE:
|
|
+ emit_sltu_r64(ctx, t1, dst, src);
|
|
+ emit(ctx, beqz, t1, off);
|
|
+ break;
|
|
+ /* PC += off if dst < src */
|
|
+ case BPF_JLT:
|
|
+ emit_sltu_r64(ctx, t1, dst, src);
|
|
+ emit(ctx, bnez, t1, off);
|
|
+ break;
|
|
+ /* PC += off if dst <= src */
|
|
+ case BPF_JLE:
|
|
+ emit_sltu_r64(ctx, t1, src, dst);
|
|
+ emit(ctx, beqz, t1, off);
|
|
+ break;
|
|
+ /* PC += off if dst > src (signed) */
|
|
+ case BPF_JSGT:
|
|
+ emit_slt_r64(ctx, t1, src, dst);
|
|
+ emit(ctx, bnez, t1, off);
|
|
+ break;
|
|
+ /* PC += off if dst >= src (signed) */
|
|
+ case BPF_JSGE:
|
|
+ emit_slt_r64(ctx, t1, dst, src);
|
|
+ emit(ctx, beqz, t1, off);
|
|
+ break;
|
|
+ /* PC += off if dst < src (signed) */
|
|
+ case BPF_JSLT:
|
|
+ emit_slt_r64(ctx, t1, dst, src);
|
|
+ emit(ctx, bnez, t1, off);
|
|
+ break;
|
|
+ /* PC += off if dst <= src (signed) */
|
|
+ case BPF_JSLE:
|
|
+ emit_slt_r64(ctx, t1, src, dst);
|
|
+ emit(ctx, beqz, t1, off);
|
|
+ break;
|
|
+ }
|
|
+}
|
|
+
|
|
+/* Function call */
|
|
+static int emit_call(struct jit_context *ctx, const struct bpf_insn *insn)
|
|
+{
|
|
+ bool fixed;
|
|
+ u64 addr;
|
|
+
|
|
+ /* Decode the call address */
|
|
+ if (bpf_jit_get_func_addr(ctx->program, insn, false,
|
|
+ &addr, &fixed) < 0)
|
|
+ return -1;
|
|
+ if (!fixed)
|
|
+ return -1;
|
|
+
|
|
+ /* Push stack arguments */
|
|
+ push_regs(ctx, JIT_STACK_REGS, 0, JIT_RESERVED_STACK);
|
|
+
|
|
+ /* Emit function call */
|
|
+ emit_mov_i(ctx, MIPS_R_T9, addr);
|
|
+ emit(ctx, jalr, MIPS_R_RA, MIPS_R_T9);
|
|
+ emit(ctx, nop); /* Delay slot */
|
|
+
|
|
+ clobber_reg(ctx, MIPS_R_RA);
|
|
+ clobber_reg(ctx, MIPS_R_V0);
|
|
+ clobber_reg(ctx, MIPS_R_V1);
|
|
+ return 0;
|
|
+}
|
|
+
|
|
+/* Function tail call */
|
|
+static int emit_tail_call(struct jit_context *ctx)
|
|
+{
|
|
+ u8 ary = lo(bpf2mips32[BPF_REG_2]);
|
|
+ u8 ind = lo(bpf2mips32[BPF_REG_3]);
|
|
+ u8 t1 = MIPS_R_T8;
|
|
+ u8 t2 = MIPS_R_T9;
|
|
+ int off;
|
|
+
|
|
+ /*
|
|
+ * Tail call:
|
|
+ * eBPF R1 - function argument (context ptr), passed in a0-a1
|
|
+ * eBPF R2 - ptr to object with array of function entry points
|
|
+ * eBPF R3 - array index of function to be called
|
|
+ * stack[sz] - remaining tail call count, initialized in prologue
|
|
+ */
|
|
+
|
|
+ /* if (ind >= ary->map.max_entries) goto out */
|
|
+ off = offsetof(struct bpf_array, map.max_entries);
|
|
+ if (off > 0x7fff)
|
|
+ return -1;
|
|
+ emit(ctx, lw, t1, off, ary); /* t1 = ary->map.max_entries*/
|
|
+ emit_load_delay(ctx); /* Load delay slot */
|
|
+ emit(ctx, sltu, t1, ind, t1); /* t1 = ind < t1 */
|
|
+ emit(ctx, beqz, t1, get_offset(ctx, 1)); /* PC += off(1) if t1 == 0 */
|
|
+ /* (next insn delay slot) */
|
|
+ /* if (TCC-- <= 0) goto out */
|
|
+ emit(ctx, lw, t2, ctx->stack_size, MIPS_R_SP); /* t2 = *(SP + size) */
|
|
+ emit_load_delay(ctx); /* Load delay slot */
|
|
+ emit(ctx, blez, t2, get_offset(ctx, 1)); /* PC += off(1) if t2 < 0 */
|
|
+ emit(ctx, addiu, t2, t2, -1); /* t2-- (delay slot) */
|
|
+ emit(ctx, sw, t2, ctx->stack_size, MIPS_R_SP); /* *(SP + size) = t2 */
|
|
+
|
|
+ /* prog = ary->ptrs[ind] */
|
|
+ off = offsetof(struct bpf_array, ptrs);
|
|
+ if (off > 0x7fff)
|
|
+ return -1;
|
|
+ emit(ctx, sll, t1, ind, 2); /* t1 = ind << 2 */
|
|
+ emit(ctx, addu, t1, t1, ary); /* t1 += ary */
|
|
+ emit(ctx, lw, t2, off, t1); /* t2 = *(t1 + off) */
|
|
+ emit_load_delay(ctx); /* Load delay slot */
|
|
+
|
|
+ /* if (prog == 0) goto out */
|
|
+ emit(ctx, beqz, t2, get_offset(ctx, 1)); /* PC += off(1) if t2 == 0 */
|
|
+ emit(ctx, nop); /* Delay slot */
|
|
+
|
|
+ /* func = prog->bpf_func + 8 (prologue skip offset) */
|
|
+ off = offsetof(struct bpf_prog, bpf_func);
|
|
+ if (off > 0x7fff)
|
|
+ return -1;
|
|
+ emit(ctx, lw, t1, off, t2); /* t1 = *(t2 + off) */
|
|
+ emit_load_delay(ctx); /* Load delay slot */
|
|
+ emit(ctx, addiu, t1, t1, JIT_TCALL_SKIP); /* t1 += skip (8 or 12) */
|
|
+
|
|
+ /* goto func */
|
|
+ build_epilogue(ctx, t1);
|
|
+ return 0;
|
|
+}
|
|
+
|
|
+/*
|
|
+ * Stack frame layout for a JITed program (stack grows down).
|
|
+ *
|
|
+ * Higher address : Caller's stack frame :
|
|
+ * :----------------------------:
|
|
+ * : 64-bit eBPF args r3-r5 :
|
|
+ * :----------------------------:
|
|
+ * : Reserved / tail call count :
|
|
+ * +============================+ <--- MIPS sp before call
|
|
+ * | Callee-saved registers, |
|
|
+ * | including RA and FP |
|
|
+ * +----------------------------+ <--- eBPF FP (MIPS zero,fp)
|
|
+ * | Local eBPF variables |
|
|
+ * | allocated by program |
|
|
+ * +----------------------------+
|
|
+ * | Reserved for caller-saved |
|
|
+ * | registers |
|
|
+ * +----------------------------+
|
|
+ * | Reserved for 64-bit eBPF |
|
|
+ * | args r3-r5 & args passed |
|
|
+ * | on stack in kernel calls |
|
|
+ * Lower address +============================+ <--- MIPS sp
|
|
+ */
|
|
+
|
|
+/* Build program prologue to set up the stack and registers */
|
|
+void build_prologue(struct jit_context *ctx)
|
|
+{
|
|
+ const u8 *r1 = bpf2mips32[BPF_REG_1];
|
|
+ const u8 *fp = bpf2mips32[BPF_REG_FP];
|
|
+ int stack, saved, locals, reserved;
|
|
+
|
|
+ /*
|
|
+ * The first two instructions initialize TCC in the reserved (for us)
|
|
+ * 16-byte area in the parent's stack frame. On a tail call, the
|
|
+ * calling function jumps into the prologue after these instructions.
|
|
+ */
|
|
+ emit(ctx, ori, MIPS_R_T9, MIPS_R_ZERO,
|
|
+ min(MAX_TAIL_CALL_CNT + 1, 0xffff));
|
|
+ emit(ctx, sw, MIPS_R_T9, 0, MIPS_R_SP);
|
|
+
|
|
+ /*
|
|
+ * Register eBPF R1 contains the 32-bit context pointer argument.
|
|
+ * A 32-bit argument is always passed in MIPS register a0, regardless
|
|
+ * of CPU endianness. Initialize R1 accordingly and zero-extend.
|
|
+ */
|
|
+#ifdef __BIG_ENDIAN
|
|
+ emit(ctx, move, lo(r1), MIPS_R_A0);
|
|
+#endif
|
|
+
|
|
+ /* === Entry-point for tail calls === */
|
|
+
|
|
+ /* Zero-extend the 32-bit argument */
|
|
+ emit(ctx, move, hi(r1), MIPS_R_ZERO);
|
|
+
|
|
+ /* If the eBPF frame pointer was accessed it must be saved */
|
|
+ if (ctx->accessed & BIT(BPF_REG_FP))
|
|
+ clobber_reg64(ctx, fp);
|
|
+
|
|
+ /* Compute the stack space needed for callee-saved registers */
|
|
+ saved = hweight32(ctx->clobbered & JIT_CALLEE_REGS) * sizeof(u32);
|
|
+ saved = ALIGN(saved, MIPS_STACK_ALIGNMENT);
|
|
+
|
|
+ /* Stack space used by eBPF program local data */
|
|
+ locals = ALIGN(ctx->program->aux->stack_depth, MIPS_STACK_ALIGNMENT);
|
|
+
|
|
+ /*
|
|
+ * If we are emitting function calls, reserve extra stack space for
|
|
+ * caller-saved registers and function arguments passed on the stack.
|
|
+ * The required space is computed automatically during resource
|
|
+ * usage discovery (pass 1).
|
|
+ */
|
|
+ reserved = ctx->stack_used;
|
|
+
|
|
+ /* Allocate the stack frame */
|
|
+ stack = ALIGN(saved + locals + reserved, MIPS_STACK_ALIGNMENT);
|
|
+ emit(ctx, addiu, MIPS_R_SP, MIPS_R_SP, -stack);
|
|
+
|
|
+ /* Store callee-saved registers on stack */
|
|
+ push_regs(ctx, ctx->clobbered & JIT_CALLEE_REGS, 0, stack - saved);
|
|
+
|
|
+ /* Initialize the eBPF frame pointer if accessed */
|
|
+ if (ctx->accessed & BIT(BPF_REG_FP))
|
|
+ emit(ctx, addiu, lo(fp), MIPS_R_SP, stack - saved);
|
|
+
|
|
+ ctx->saved_size = saved;
|
|
+ ctx->stack_size = stack;
|
|
+}
|
|
+
|
|
+/* Build the program epilogue to restore the stack and registers */
|
|
+void build_epilogue(struct jit_context *ctx, int dest_reg)
|
|
+{
|
|
+ /* Restore callee-saved registers from stack */
|
|
+ pop_regs(ctx, ctx->clobbered & JIT_CALLEE_REGS, 0,
|
|
+ ctx->stack_size - ctx->saved_size);
|
|
+ /*
|
|
+ * A 32-bit return value is always passed in MIPS register v0,
|
|
+ * but on big-endian targets the low part of R0 is mapped to v1.
|
|
+ */
|
|
+#ifdef __BIG_ENDIAN
|
|
+ emit(ctx, move, MIPS_R_V0, MIPS_R_V1);
|
|
+#endif
|
|
+
|
|
+ /* Jump to the return address and adjust the stack pointer */
|
|
+ emit(ctx, jr, dest_reg);
|
|
+ emit(ctx, addiu, MIPS_R_SP, MIPS_R_SP, ctx->stack_size);
|
|
+}
|
|
+
|
|
+/* Build one eBPF instruction */
|
|
+int build_insn(const struct bpf_insn *insn, struct jit_context *ctx)
|
|
+{
|
|
+ const u8 *dst = bpf2mips32[insn->dst_reg];
|
|
+ const u8 *src = bpf2mips32[insn->src_reg];
|
|
+ const u8 *tmp = bpf2mips32[JIT_REG_TMP];
|
|
+ u8 code = insn->code;
|
|
+ s16 off = insn->off;
|
|
+ s32 imm = insn->imm;
|
|
+ s32 val, rel;
|
|
+ u8 alu, jmp;
|
|
+
|
|
+ switch (code) {
|
|
+ /* ALU operations */
|
|
+ /* dst = imm */
|
|
+ case BPF_ALU | BPF_MOV | BPF_K:
|
|
+ emit_mov_i(ctx, lo(dst), imm);
|
|
+ emit_zext_ver(ctx, dst);
|
|
+ break;
|
|
+ /* dst = src */
|
|
+ case BPF_ALU | BPF_MOV | BPF_X:
|
|
+ if (imm == 1) {
|
|
+ /* Special mov32 for zext */
|
|
+ emit_mov_i(ctx, hi(dst), 0);
|
|
+ } else {
|
|
+ emit_mov_r(ctx, lo(dst), lo(src));
|
|
+ emit_zext_ver(ctx, dst);
|
|
+ }
|
|
+ break;
|
|
+ /* dst = -dst */
|
|
+ case BPF_ALU | BPF_NEG:
|
|
+ emit_alu_i(ctx, lo(dst), 0, BPF_NEG);
|
|
+ emit_zext_ver(ctx, dst);
|
|
+ break;
|
|
+ /* dst = dst & imm */
|
|
+ /* dst = dst | imm */
|
|
+ /* dst = dst ^ imm */
|
|
+ /* dst = dst << imm */
|
|
+ /* dst = dst >> imm */
|
|
+ /* dst = dst >> imm (arithmetic) */
|
|
+ /* dst = dst + imm */
|
|
+ /* dst = dst - imm */
|
|
+ /* dst = dst * imm */
|
|
+ /* dst = dst / imm */
|
|
+ /* dst = dst % imm */
|
|
+ case BPF_ALU | BPF_OR | BPF_K:
|
|
+ case BPF_ALU | BPF_AND | BPF_K:
|
|
+ case BPF_ALU | BPF_XOR | BPF_K:
|
|
+ case BPF_ALU | BPF_LSH | BPF_K:
|
|
+ case BPF_ALU | BPF_RSH | BPF_K:
|
|
+ case BPF_ALU | BPF_ARSH | BPF_K:
|
|
+ case BPF_ALU | BPF_ADD | BPF_K:
|
|
+ case BPF_ALU | BPF_SUB | BPF_K:
|
|
+ case BPF_ALU | BPF_MUL | BPF_K:
|
|
+ case BPF_ALU | BPF_DIV | BPF_K:
|
|
+ case BPF_ALU | BPF_MOD | BPF_K:
|
|
+ if (!valid_alu_i(BPF_OP(code), imm)) {
|
|
+ emit_mov_i(ctx, MIPS_R_T6, imm);
|
|
+ emit_alu_r(ctx, lo(dst), MIPS_R_T6, BPF_OP(code));
|
|
+ } else if (rewrite_alu_i(BPF_OP(code), imm, &alu, &val)) {
|
|
+ emit_alu_i(ctx, lo(dst), val, alu);
|
|
+ }
|
|
+ emit_zext_ver(ctx, dst);
|
|
+ break;
|
|
+ /* dst = dst & src */
|
|
+ /* dst = dst | src */
|
|
+ /* dst = dst ^ src */
|
|
+ /* dst = dst << src */
|
|
+ /* dst = dst >> src */
|
|
+ /* dst = dst >> src (arithmetic) */
|
|
+ /* dst = dst + src */
|
|
+ /* dst = dst - src */
|
|
+ /* dst = dst * src */
|
|
+ /* dst = dst / src */
|
|
+ /* dst = dst % src */
|
|
+ case BPF_ALU | BPF_AND | BPF_X:
|
|
+ case BPF_ALU | BPF_OR | BPF_X:
|
|
+ case BPF_ALU | BPF_XOR | BPF_X:
|
|
+ case BPF_ALU | BPF_LSH | BPF_X:
|
|
+ case BPF_ALU | BPF_RSH | BPF_X:
|
|
+ case BPF_ALU | BPF_ARSH | BPF_X:
|
|
+ case BPF_ALU | BPF_ADD | BPF_X:
|
|
+ case BPF_ALU | BPF_SUB | BPF_X:
|
|
+ case BPF_ALU | BPF_MUL | BPF_X:
|
|
+ case BPF_ALU | BPF_DIV | BPF_X:
|
|
+ case BPF_ALU | BPF_MOD | BPF_X:
|
|
+ emit_alu_r(ctx, lo(dst), lo(src), BPF_OP(code));
|
|
+ emit_zext_ver(ctx, dst);
|
|
+ break;
|
|
+ /* dst = imm (64-bit) */
|
|
+ case BPF_ALU64 | BPF_MOV | BPF_K:
|
|
+ emit_mov_se_i64(ctx, dst, imm);
|
|
+ break;
|
|
+ /* dst = src (64-bit) */
|
|
+ case BPF_ALU64 | BPF_MOV | BPF_X:
|
|
+ emit_mov_r(ctx, lo(dst), lo(src));
|
|
+ emit_mov_r(ctx, hi(dst), hi(src));
|
|
+ break;
|
|
+ /* dst = -dst (64-bit) */
|
|
+ case BPF_ALU64 | BPF_NEG:
|
|
+ emit_neg_i64(ctx, dst);
|
|
+ break;
|
|
+ /* dst = dst & imm (64-bit) */
|
|
+ case BPF_ALU64 | BPF_AND | BPF_K:
|
|
+ emit_alu_i64(ctx, dst, imm, BPF_OP(code));
|
|
+ break;
|
|
+ /* dst = dst | imm (64-bit) */
|
|
+ /* dst = dst ^ imm (64-bit) */
|
|
+ /* dst = dst + imm (64-bit) */
|
|
+ /* dst = dst - imm (64-bit) */
|
|
+ case BPF_ALU64 | BPF_OR | BPF_K:
|
|
+ case BPF_ALU64 | BPF_XOR | BPF_K:
|
|
+ case BPF_ALU64 | BPF_ADD | BPF_K:
|
|
+ case BPF_ALU64 | BPF_SUB | BPF_K:
|
|
+ if (imm)
|
|
+ emit_alu_i64(ctx, dst, imm, BPF_OP(code));
|
|
+ break;
|
|
+ /* dst = dst << imm (64-bit) */
|
|
+ /* dst = dst >> imm (64-bit) */
|
|
+ /* dst = dst >> imm (64-bit, arithmetic) */
|
|
+ case BPF_ALU64 | BPF_LSH | BPF_K:
|
|
+ case BPF_ALU64 | BPF_RSH | BPF_K:
|
|
+ case BPF_ALU64 | BPF_ARSH | BPF_K:
|
|
+ if (imm)
|
|
+ emit_shift_i64(ctx, dst, imm, BPF_OP(code));
|
|
+ break;
|
|
+ /* dst = dst * imm (64-bit) */
|
|
+ case BPF_ALU64 | BPF_MUL | BPF_K:
|
|
+ emit_mul_i64(ctx, dst, imm);
|
|
+ break;
|
|
+ /* dst = dst / imm (64-bit) */
|
|
+ /* dst = dst % imm (64-bit) */
|
|
+ case BPF_ALU64 | BPF_DIV | BPF_K:
|
|
+ case BPF_ALU64 | BPF_MOD | BPF_K:
|
|
+ /*
|
|
+ * Sign-extend the immediate value into a temporary register,
|
|
+ * and then do the operation on this register.
|
|
+ */
|
|
+ emit_mov_se_i64(ctx, tmp, imm);
|
|
+ emit_divmod_r64(ctx, dst, tmp, BPF_OP(code));
|
|
+ break;
|
|
+ /* dst = dst & src (64-bit) */
|
|
+ /* dst = dst | src (64-bit) */
|
|
+ /* dst = dst ^ src (64-bit) */
|
|
+ /* dst = dst + src (64-bit) */
|
|
+ /* dst = dst - src (64-bit) */
|
|
+ case BPF_ALU64 | BPF_AND | BPF_X:
|
|
+ case BPF_ALU64 | BPF_OR | BPF_X:
|
|
+ case BPF_ALU64 | BPF_XOR | BPF_X:
|
|
+ case BPF_ALU64 | BPF_ADD | BPF_X:
|
|
+ case BPF_ALU64 | BPF_SUB | BPF_X:
|
|
+ emit_alu_r64(ctx, dst, src, BPF_OP(code));
|
|
+ break;
|
|
+ /* dst = dst << src (64-bit) */
|
|
+ /* dst = dst >> src (64-bit) */
|
|
+ /* dst = dst >> src (64-bit, arithmetic) */
|
|
+ case BPF_ALU64 | BPF_LSH | BPF_X:
|
|
+ case BPF_ALU64 | BPF_RSH | BPF_X:
|
|
+ case BPF_ALU64 | BPF_ARSH | BPF_X:
|
|
+ emit_shift_r64(ctx, dst, lo(src), BPF_OP(code));
|
|
+ break;
|
|
+ /* dst = dst * src (64-bit) */
|
|
+ case BPF_ALU64 | BPF_MUL | BPF_X:
|
|
+ emit_mul_r64(ctx, dst, src);
|
|
+ break;
|
|
+ /* dst = dst / src (64-bit) */
|
|
+ /* dst = dst % src (64-bit) */
|
|
+ case BPF_ALU64 | BPF_DIV | BPF_X:
|
|
+ case BPF_ALU64 | BPF_MOD | BPF_X:
|
|
+ emit_divmod_r64(ctx, dst, src, BPF_OP(code));
|
|
+ break;
|
|
+ /* dst = htole(dst) */
|
|
+ /* dst = htobe(dst) */
|
|
+ case BPF_ALU | BPF_END | BPF_FROM_LE:
|
|
+ case BPF_ALU | BPF_END | BPF_FROM_BE:
|
|
+ if (BPF_SRC(code) ==
|
|
+#ifdef __BIG_ENDIAN
|
|
+ BPF_FROM_LE
|
|
+#else
|
|
+ BPF_FROM_BE
|
|
+#endif
|
|
+ )
|
|
+ emit_bswap_r64(ctx, dst, imm);
|
|
+ else
|
|
+ emit_trunc_r64(ctx, dst, imm);
|
|
+ break;
|
|
+ /* dst = imm64 */
|
|
+ case BPF_LD | BPF_IMM | BPF_DW:
|
|
+ emit_mov_i(ctx, lo(dst), imm);
|
|
+ emit_mov_i(ctx, hi(dst), insn[1].imm);
|
|
+ return 1;
|
|
+ /* LDX: dst = *(size *)(src + off) */
|
|
+ case BPF_LDX | BPF_MEM | BPF_W:
|
|
+ case BPF_LDX | BPF_MEM | BPF_H:
|
|
+ case BPF_LDX | BPF_MEM | BPF_B:
|
|
+ case BPF_LDX | BPF_MEM | BPF_DW:
|
|
+ emit_ldx(ctx, dst, lo(src), off, BPF_SIZE(code));
|
|
+ break;
|
|
+ /* ST: *(size *)(dst + off) = imm */
|
|
+ case BPF_ST | BPF_MEM | BPF_W:
|
|
+ case BPF_ST | BPF_MEM | BPF_H:
|
|
+ case BPF_ST | BPF_MEM | BPF_B:
|
|
+ case BPF_ST | BPF_MEM | BPF_DW:
|
|
+ switch (BPF_SIZE(code)) {
|
|
+ case BPF_DW:
|
|
+ /* Sign-extend immediate value into temporary reg */
|
|
+ emit_mov_se_i64(ctx, tmp, imm);
|
|
+ break;
|
|
+ case BPF_W:
|
|
+ case BPF_H:
|
|
+ case BPF_B:
|
|
+ emit_mov_i(ctx, lo(tmp), imm);
|
|
+ break;
|
|
+ }
|
|
+ emit_stx(ctx, lo(dst), tmp, off, BPF_SIZE(code));
|
|
+ break;
|
|
+ /* STX: *(size *)(dst + off) = src */
|
|
+ case BPF_STX | BPF_MEM | BPF_W:
|
|
+ case BPF_STX | BPF_MEM | BPF_H:
|
|
+ case BPF_STX | BPF_MEM | BPF_B:
|
|
+ case BPF_STX | BPF_MEM | BPF_DW:
|
|
+ emit_stx(ctx, lo(dst), src, off, BPF_SIZE(code));
|
|
+ break;
|
|
+ /* Speculation barrier */
|
|
+ case BPF_ST | BPF_NOSPEC:
|
|
+ break;
|
|
+ /* Atomics */
|
|
+ case BPF_STX | BPF_XADD | BPF_W:
|
|
+ switch (imm) {
|
|
+ case BPF_ADD:
|
|
+ case BPF_AND:
|
|
+ case BPF_OR:
|
|
+ case BPF_XOR:
|
|
+ if (cpu_has_llsc)
|
|
+ emit_atomic_r(ctx, lo(dst), lo(src), off, imm);
|
|
+ else /* Non-ll/sc fallback */
|
|
+ emit_atomic_r32(ctx, lo(dst), lo(src),
|
|
+ off, imm);
|
|
+ break;
|
|
+ default:
|
|
+ goto notyet;
|
|
+ }
|
|
+ break;
|
|
+ /* Atomics (64-bit) */
|
|
+ case BPF_STX | BPF_XADD | BPF_DW:
|
|
+ switch (imm) {
|
|
+ case BPF_ADD:
|
|
+ case BPF_AND:
|
|
+ case BPF_OR:
|
|
+ case BPF_XOR:
|
|
+ emit_atomic_r64(ctx, lo(dst), src, off, imm);
|
|
+ break;
|
|
+ default:
|
|
+ goto notyet;
|
|
+ }
|
|
+ break;
|
|
+ /* PC += off if dst == src */
|
|
+ /* PC += off if dst != src */
|
|
+ /* PC += off if dst & src */
|
|
+ /* PC += off if dst > src */
|
|
+ /* PC += off if dst >= src */
|
|
+ /* PC += off if dst < src */
|
|
+ /* PC += off if dst <= src */
|
|
+ /* PC += off if dst > src (signed) */
|
|
+ /* PC += off if dst >= src (signed) */
|
|
+ /* PC += off if dst < src (signed) */
|
|
+ /* PC += off if dst <= src (signed) */
|
|
+ case BPF_JMP32 | BPF_JEQ | BPF_X:
|
|
+ case BPF_JMP32 | BPF_JNE | BPF_X:
|
|
+ case BPF_JMP32 | BPF_JSET | BPF_X:
|
|
+ case BPF_JMP32 | BPF_JGT | BPF_X:
|
|
+ case BPF_JMP32 | BPF_JGE | BPF_X:
|
|
+ case BPF_JMP32 | BPF_JLT | BPF_X:
|
|
+ case BPF_JMP32 | BPF_JLE | BPF_X:
|
|
+ case BPF_JMP32 | BPF_JSGT | BPF_X:
|
|
+ case BPF_JMP32 | BPF_JSGE | BPF_X:
|
|
+ case BPF_JMP32 | BPF_JSLT | BPF_X:
|
|
+ case BPF_JMP32 | BPF_JSLE | BPF_X:
|
|
+ if (off == 0)
|
|
+ break;
|
|
+ setup_jmp_r(ctx, dst == src, BPF_OP(code), off, &jmp, &rel);
|
|
+ emit_jmp_r(ctx, lo(dst), lo(src), rel, jmp);
|
|
+ if (finish_jmp(ctx, jmp, off) < 0)
|
|
+ goto toofar;
|
|
+ break;
|
|
+ /* PC += off if dst == imm */
|
|
+ /* PC += off if dst != imm */
|
|
+ /* PC += off if dst & imm */
|
|
+ /* PC += off if dst > imm */
|
|
+ /* PC += off if dst >= imm */
|
|
+ /* PC += off if dst < imm */
|
|
+ /* PC += off if dst <= imm */
|
|
+ /* PC += off if dst > imm (signed) */
|
|
+ /* PC += off if dst >= imm (signed) */
|
|
+ /* PC += off if dst < imm (signed) */
|
|
+ /* PC += off if dst <= imm (signed) */
|
|
+ case BPF_JMP32 | BPF_JEQ | BPF_K:
|
|
+ case BPF_JMP32 | BPF_JNE | BPF_K:
|
|
+ case BPF_JMP32 | BPF_JSET | BPF_K:
|
|
+ case BPF_JMP32 | BPF_JGT | BPF_K:
|
|
+ case BPF_JMP32 | BPF_JGE | BPF_K:
|
|
+ case BPF_JMP32 | BPF_JLT | BPF_K:
|
|
+ case BPF_JMP32 | BPF_JLE | BPF_K:
|
|
+ case BPF_JMP32 | BPF_JSGT | BPF_K:
|
|
+ case BPF_JMP32 | BPF_JSGE | BPF_K:
|
|
+ case BPF_JMP32 | BPF_JSLT | BPF_K:
|
|
+ case BPF_JMP32 | BPF_JSLE | BPF_K:
|
|
+ if (off == 0)
|
|
+ break;
|
|
+ setup_jmp_i(ctx, imm, 32, BPF_OP(code), off, &jmp, &rel);
|
|
+ if (valid_jmp_i(jmp, imm)) {
|
|
+ emit_jmp_i(ctx, lo(dst), imm, rel, jmp);
|
|
+ } else {
|
|
+ /* Move large immediate to register */
|
|
+ emit_mov_i(ctx, MIPS_R_T6, imm);
|
|
+ emit_jmp_r(ctx, lo(dst), MIPS_R_T6, rel, jmp);
|
|
+ }
|
|
+ if (finish_jmp(ctx, jmp, off) < 0)
|
|
+ goto toofar;
|
|
+ break;
|
|
+ /* PC += off if dst == src */
|
|
+ /* PC += off if dst != src */
|
|
+ /* PC += off if dst & src */
|
|
+ /* PC += off if dst > src */
|
|
+ /* PC += off if dst >= src */
|
|
+ /* PC += off if dst < src */
|
|
+ /* PC += off if dst <= src */
|
|
+ /* PC += off if dst > src (signed) */
|
|
+ /* PC += off if dst >= src (signed) */
|
|
+ /* PC += off if dst < src (signed) */
|
|
+ /* PC += off if dst <= src (signed) */
|
|
+ case BPF_JMP | BPF_JEQ | BPF_X:
|
|
+ case BPF_JMP | BPF_JNE | BPF_X:
|
|
+ case BPF_JMP | BPF_JSET | BPF_X:
|
|
+ case BPF_JMP | BPF_JGT | BPF_X:
|
|
+ case BPF_JMP | BPF_JGE | BPF_X:
|
|
+ case BPF_JMP | BPF_JLT | BPF_X:
|
|
+ case BPF_JMP | BPF_JLE | BPF_X:
|
|
+ case BPF_JMP | BPF_JSGT | BPF_X:
|
|
+ case BPF_JMP | BPF_JSGE | BPF_X:
|
|
+ case BPF_JMP | BPF_JSLT | BPF_X:
|
|
+ case BPF_JMP | BPF_JSLE | BPF_X:
|
|
+ if (off == 0)
|
|
+ break;
|
|
+ setup_jmp_r(ctx, dst == src, BPF_OP(code), off, &jmp, &rel);
|
|
+ emit_jmp_r64(ctx, dst, src, rel, jmp);
|
|
+ if (finish_jmp(ctx, jmp, off) < 0)
|
|
+ goto toofar;
|
|
+ break;
|
|
+ /* PC += off if dst == imm */
|
|
+ /* PC += off if dst != imm */
|
|
+ /* PC += off if dst & imm */
|
|
+ /* PC += off if dst > imm */
|
|
+ /* PC += off if dst >= imm */
|
|
+ /* PC += off if dst < imm */
|
|
+ /* PC += off if dst <= imm */
|
|
+ /* PC += off if dst > imm (signed) */
|
|
+ /* PC += off if dst >= imm (signed) */
|
|
+ /* PC += off if dst < imm (signed) */
|
|
+ /* PC += off if dst <= imm (signed) */
|
|
+ case BPF_JMP | BPF_JEQ | BPF_K:
|
|
+ case BPF_JMP | BPF_JNE | BPF_K:
|
|
+ case BPF_JMP | BPF_JSET | BPF_K:
|
|
+ case BPF_JMP | BPF_JGT | BPF_K:
|
|
+ case BPF_JMP | BPF_JGE | BPF_K:
|
|
+ case BPF_JMP | BPF_JLT | BPF_K:
|
|
+ case BPF_JMP | BPF_JLE | BPF_K:
|
|
+ case BPF_JMP | BPF_JSGT | BPF_K:
|
|
+ case BPF_JMP | BPF_JSGE | BPF_K:
|
|
+ case BPF_JMP | BPF_JSLT | BPF_K:
|
|
+ case BPF_JMP | BPF_JSLE | BPF_K:
|
|
+ if (off == 0)
|
|
+ break;
|
|
+ setup_jmp_i(ctx, imm, 64, BPF_OP(code), off, &jmp, &rel);
|
|
+ emit_jmp_i64(ctx, dst, imm, rel, jmp);
|
|
+ if (finish_jmp(ctx, jmp, off) < 0)
|
|
+ goto toofar;
|
|
+ break;
|
|
+ /* PC += off */
|
|
+ case BPF_JMP | BPF_JA:
|
|
+ if (off == 0)
|
|
+ break;
|
|
+ if (emit_ja(ctx, off) < 0)
|
|
+ goto toofar;
|
|
+ break;
|
|
+ /* Tail call */
|
|
+ case BPF_JMP | BPF_TAIL_CALL:
|
|
+ if (emit_tail_call(ctx) < 0)
|
|
+ goto invalid;
|
|
+ break;
|
|
+ /* Function call */
|
|
+ case BPF_JMP | BPF_CALL:
|
|
+ if (emit_call(ctx, insn) < 0)
|
|
+ goto invalid;
|
|
+ break;
|
|
+ /* Function return */
|
|
+ case BPF_JMP | BPF_EXIT:
|
|
+ /*
|
|
+ * Optimization: when last instruction is EXIT
|
|
+ * simply continue to epilogue.
|
|
+ */
|
|
+ if (ctx->bpf_index == ctx->program->len - 1)
|
|
+ break;
|
|
+ if (emit_exit(ctx) < 0)
|
|
+ goto toofar;
|
|
+ break;
|
|
+
|
|
+ default:
|
|
+invalid:
|
|
+ pr_err_once("unknown opcode %02x\n", code);
|
|
+ return -EINVAL;
|
|
+notyet:
|
|
+ pr_info_once("*** NOT YET: opcode %02x ***\n", code);
|
|
+ return -EFAULT;
|
|
+toofar:
|
|
+ pr_info_once("*** TOO FAR: jump at %u opcode %02x ***\n",
|
|
+ ctx->bpf_index, code);
|
|
+ return -E2BIG;
|
|
+ }
|
|
+ return 0;
|
|
+}
|