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Refactor - Move memory instruction classes (#603)
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* Removes unused items of InstructionType in assembler.

* Adds missing differentiation for PQR instructions in disassembler.

* Adds the new opcodes.

* Adds a feature flag for moving them.

* Disables the old opcodes conditionally.

* Enables the new opcodes conditionally in the verifier.

* Enables the new opcodes conditionally in the dis-/assembler.

* Enables the new opcodes conditionally in the interpreter and JIT.

* Renames BPF_ALU => BPF_ALU32_LOAD.
Renames BPF_ALU64 => BPF_ALU64_STORE.

* Adds test coverage for both before and after.
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Lichtso authored Oct 8, 2024
1 parent 67df8e1 commit c6c1929
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Showing 13 changed files with 579 additions and 505 deletions.
90 changes: 45 additions & 45 deletions src/assembler.rs
Original file line number Diff line number Diff line change
Expand Up @@ -8,8 +8,8 @@
//! This module translates eBPF assembly language to binary.

use self::InstructionType::{
AluBinary, AluUnary, CallImm, CallReg, Endian, JumpConditional, JumpUnconditional, LoadAbs,
LoadDwImm, LoadInd, LoadReg, NoOperand, StoreImm, StoreReg, Syscall,
AluBinary, AluUnary, CallImm, CallReg, Endian, JumpConditional, JumpUnconditional, LoadDwImm,
LoadReg, NoOperand, StoreImm, StoreReg, Syscall,
};
use crate::{
asm_parser::{
Expand All @@ -19,7 +19,7 @@ use crate::{
},
ebpf::{self, Insn},
elf::Executable,
program::{BuiltinProgram, FunctionRegistry},
program::{BuiltinProgram, FunctionRegistry, SBPFVersion},
vm::ContextObject,
};
use std::collections::HashMap;
Expand All @@ -35,8 +35,6 @@ enum InstructionType {
AluBinary,
AluUnary,
LoadDwImm,
LoadAbs,
LoadInd,
LoadReg,
StoreImm,
StoreReg,
Expand All @@ -49,7 +47,7 @@ enum InstructionType {
NoOperand,
}

fn make_instruction_map() -> HashMap<String, (InstructionType, u8)> {
fn make_instruction_map(sbpf_version: &SBPFVersion) -> HashMap<String, (InstructionType, u8)> {
let mut result = HashMap::new();

let alu_binary_ops = [
Expand All @@ -68,11 +66,31 @@ fn make_instruction_map() -> HashMap<String, (InstructionType, u8)> {
("hor", ebpf::BPF_HOR),
];

let mem_classes = [
(
"ldx",
LoadReg,
ebpf::BPF_MEM | ebpf::BPF_LDX,
ebpf::BPF_ALU32_LOAD | ebpf::BPF_X,
),
(
"st",
StoreImm,
ebpf::BPF_MEM | ebpf::BPF_ST,
ebpf::BPF_ALU64_STORE | ebpf::BPF_K,
),
(
"stx",
StoreReg,
ebpf::BPF_MEM | ebpf::BPF_STX,
ebpf::BPF_ALU64_STORE | ebpf::BPF_X,
),
];
let mem_sizes = [
("w", ebpf::BPF_W),
("h", ebpf::BPF_H),
("b", ebpf::BPF_B),
("dw", ebpf::BPF_DW),
("b", ebpf::BPF_B, ebpf::BPF_1B),
("h", ebpf::BPF_H, ebpf::BPF_2B),
("w", ebpf::BPF_W, ebpf::BPF_4B),
("dw", ebpf::BPF_DW, ebpf::BPF_8B),
];

let jump_conditions = [
Expand Down Expand Up @@ -109,9 +127,9 @@ fn make_instruction_map() -> HashMap<String, (InstructionType, u8)> {

// AluBinary.
for &(name, opc) in &alu_binary_ops {
entry(name, AluBinary, ebpf::BPF_ALU64 | opc);
entry(&format!("{name}32"), AluBinary, ebpf::BPF_ALU | opc);
entry(&format!("{name}64"), AluBinary, ebpf::BPF_ALU64 | opc);
entry(name, AluBinary, ebpf::BPF_ALU64_STORE | opc);
entry(&format!("{name}32"), AluBinary, ebpf::BPF_ALU32_LOAD | opc);
entry(&format!("{name}64"), AluBinary, ebpf::BPF_ALU64_STORE | opc);
}

// Product Quotient Remainder.
Expand All @@ -136,7 +154,6 @@ fn make_instruction_map() -> HashMap<String, (InstructionType, u8)> {
AluBinary,
ebpf::BPF_PQR | ebpf::BPF_B | ebpf::BPF_UHMUL,
);
entry("uhmul32", AluBinary, ebpf::BPF_PQR | ebpf::BPF_UHMUL);
entry(
"shmul",
AluBinary,
Expand All @@ -147,7 +164,6 @@ fn make_instruction_map() -> HashMap<String, (InstructionType, u8)> {
AluBinary,
ebpf::BPF_PQR | ebpf::BPF_B | ebpf::BPF_SHMUL,
);
entry("shmul32", AluBinary, ebpf::BPF_PQR | ebpf::BPF_SHMUL);
entry(
"udiv",
AluBinary,
Expand Down Expand Up @@ -193,33 +209,19 @@ fn make_instruction_map() -> HashMap<String, (InstructionType, u8)> {
);
entry("srem32", AluBinary, ebpf::BPF_PQR | ebpf::BPF_SREM);

// LoadAbs, LoadInd, LoadReg, StoreImm, and StoreReg.
for &(suffix, size) in &mem_sizes {
entry(
&format!("ldabs{suffix}"),
LoadAbs,
ebpf::BPF_ABS | ebpf::BPF_LD | size,
);
entry(
&format!("ldind{suffix}"),
LoadInd,
ebpf::BPF_IND | ebpf::BPF_LD | size,
);
entry(
&format!("ldx{suffix}"),
LoadReg,
ebpf::BPF_MEM | ebpf::BPF_LDX | size,
);
entry(
&format!("st{suffix}"),
StoreImm,
ebpf::BPF_MEM | ebpf::BPF_ST | size,
);
entry(
&format!("stx{suffix}"),
StoreReg,
ebpf::BPF_MEM | ebpf::BPF_STX | size,
);
// Memory
if sbpf_version.move_memory_instruction_classes() {
for &(prefix, class, _, opcode) in &mem_classes {
for &(suffix, _, size) in &mem_sizes {
entry(&format!("{prefix}{suffix}"), class, opcode | size);
}
}
} else {
for &(prefix, class, opcode, _) in &mem_classes {
for &(suffix, size, _) in &mem_sizes {
entry(&format!("{prefix}{suffix}"), class, opcode | size);
}
}
}

// JumpConditional.
Expand Down Expand Up @@ -314,7 +316,7 @@ pub fn assemble<C: ContextObject>(
let sbpf_version = loader.get_config().enabled_sbpf_versions.end().clone();

let statements = parse(src)?;
let instruction_map = make_instruction_map();
let instruction_map = make_instruction_map(&sbpf_version);
let mut insn_ptr = 0;
let mut function_registry = FunctionRegistry::default();
let mut labels = HashMap::new();
Expand Down Expand Up @@ -381,8 +383,6 @@ pub fn assemble<C: ContextObject>(
insn(opc | ebpf::BPF_K, *dst, 0, 0, *imm)
}
(AluUnary, [Register(dst)]) => insn(opc, *dst, 0, 0, 0),
(LoadAbs, [Integer(imm)]) => insn(opc, 0, 0, 0, *imm),
(LoadInd, [Register(src), Integer(imm)]) => insn(opc, 0, *src, 0, *imm),
(LoadReg, [Register(dst), Memory(src, off)])
| (StoreReg, [Memory(dst, off), Register(src)]) => {
insn(opc, *dst, *src, *off, 0)
Expand Down
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