Cleanup - Rename disable_lddw to enable_lddw for consistency (#570)

* Adds disable_lddw checks in interpreter and JIT. * Inverts disable_lddw to enable_lddw.
solana-labs · May 21, 2024 · 7ef666b · 7ef666b
1 parent 899cd91
commit 7ef666b
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Showing 4 changed files with 12 additions and 12 deletions.
diff --git a/src/interpreter.rs b/src/interpreter.rs
@@ -183,7 +183,7 @@ impl<'a, 'b, C: ContextObject> Interpreter<'a, 'b, C> {
                 self.vm.stack_pointer = self.vm.stack_pointer.overflowing_add(insn.imm as u64).0;
             }
 
-            ebpf::LD_DW_IMM  => {
+            ebpf::LD_DW_IMM if self.executable.get_sbpf_version().enable_lddw() => {
                 ebpf::augment_lddw_unchecked(self.program, &mut insn);
                 self.reg[dst] = insn.imm as u64;
                 self.reg[11] += 1;
@@ -337,7 +337,7 @@ impl<'a, 'b, C: ContextObject> Interpreter<'a, 'b, C> {
             ebpf::MOV64_REG  => self.reg[dst] =  self.reg[src],
             ebpf::ARSH64_IMM => self.reg[dst] = (self.reg[dst] as i64).wrapping_shr(insn.imm as u32)      as u64,
             ebpf::ARSH64_REG => self.reg[dst] = (self.reg[dst] as i64).wrapping_shr(self.reg[src] as u32) as u64,
-            ebpf::HOR64_IMM if self.executable.get_sbpf_version().disable_lddw() => {
+            ebpf::HOR64_IMM if !self.executable.get_sbpf_version().enable_lddw() => {
                 self.reg[dst] |= (insn.imm as u64).wrapping_shl(32);
             }
 

diff --git a/src/jit.rs b/src/jit.rs
@@ -329,16 +329,16 @@ impl<'a, C: ContextObject> JitCompiler<'a, C> {
 
         // Scan through program to find actual number of instructions
         let mut pc = 0;
-        if executable.get_sbpf_version().disable_lddw() {
-            pc = program.len() / ebpf::INSN_SIZE;
-        } else {
+        if executable.get_sbpf_version().enable_lddw() {
             while (pc + 1) * ebpf::INSN_SIZE <= program.len() {
                 let insn = ebpf::get_insn_unchecked(program, pc);
                 pc += match insn.opc {
                     ebpf::LD_DW_IMM => 2,
                     _ => 1,
                 };
             }
+        } else {
+            pc = program.len() / ebpf::INSN_SIZE;
         }
 
         let mut code_length_estimate = MAX_EMPTY_PROGRAM_MACHINE_CODE_LENGTH + MAX_START_PADDING_LENGTH + MAX_MACHINE_CODE_LENGTH_PER_INSTRUCTION * pc;
@@ -414,7 +414,7 @@ impl<'a, C: ContextObject> JitCompiler<'a, C> {
                     self.emit_ins(X86Instruction::alu(OperandSize::S64, 0x81, 0, REGISTER_PTR_TO_VM, insn.imm, Some(stack_ptr_access)));
                 }
 
-                ebpf::LD_DW_IMM  => {
+                ebpf::LD_DW_IMM if self.executable.get_sbpf_version().enable_lddw() => {
                     self.emit_validate_and_profile_instruction_count(true, Some(self.pc + 2));
                     self.pc += 1;
                     self.result.pc_section[self.pc] = self.anchors[ANCHOR_CALL_UNSUPPORTED_INSTRUCTION] as usize;
@@ -584,7 +584,7 @@ impl<'a, C: ContextObject> JitCompiler<'a, C> {
                 ebpf::MOV64_REG  => self.emit_ins(X86Instruction::mov(OperandSize::S64, src, dst)),
                 ebpf::ARSH64_IMM => self.emit_shift(OperandSize::S64, 7, REGISTER_SCRATCH, dst, Some(insn.imm)),
                 ebpf::ARSH64_REG => self.emit_shift(OperandSize::S64, 7, src, dst, None),
-                ebpf::HOR64_IMM => {
+                ebpf::HOR64_IMM if !self.executable.get_sbpf_version().enable_lddw() => {
                     self.emit_sanitized_alu(OperandSize::S64, 0x09, 1, dst, (insn.imm as u64).wrapping_shl(32) as i64);
                 }
 

diff --git a/src/program.rs b/src/program.rs
@@ -35,9 +35,9 @@ impl SBPFVersion {
         self != &SBPFVersion::V1
     }
 
-    /// Disable the only two slots long instruction: LD_DW_IMM
-    pub fn disable_lddw(&self) -> bool {
-        self != &SBPFVersion::V1
+    /// Enable the only two slots long instruction: LD_DW_IMM
+    pub fn enable_lddw(&self) -> bool {
+        self == &SBPFVersion::V1
     }
 
     /// Enable the BPF_PQR instruction class

diff --git a/src/verifier.rs b/src/verifier.rs
@@ -251,7 +251,7 @@ impl Verifier for RequisiteVerifier {
             }
 
             match insn.opc {
-                ebpf::LD_DW_IMM if !sbpf_version.disable_lddw() => {
+                ebpf::LD_DW_IMM if sbpf_version.enable_lddw() => {
                     check_load_dw(prog, insn_ptr)?;
                     insn_ptr += 1;
                 },
@@ -329,7 +329,7 @@ impl Verifier for RequisiteVerifier {
                 ebpf::MOV64_REG  => {},
                 ebpf::ARSH64_IMM => { check_imm_shift(&insn, insn_ptr, 64)?; },
                 ebpf::ARSH64_REG => {},
-                ebpf::HOR64_IMM  if sbpf_version.disable_lddw() => {},
+                ebpf::HOR64_IMM  if !sbpf_version.enable_lddw() => {},
 
                 // BPF_PQR class
                 ebpf::LMUL32_IMM if sbpf_version.enable_pqr() => {},