Include new syscall instruction in the (dis)assembler (#611)

solana-labs · Oct 11, 2024 · cd19a25 · cd19a25
1 parent c168a87
commit cd19a25
Show file tree

Hide file tree

Showing 9 changed files with 48 additions and 17 deletions.
diff --git a/src/assembler.rs b/src/assembler.rs
@@ -122,7 +122,15 @@ fn make_instruction_map(sbpf_version: SBPFVersion) -> HashMap<String, (Instructi
 
         // Miscellaneous.
         entry("ja", JumpUnconditional, ebpf::JA);
-        entry("syscall", Syscall, ebpf::CALL_IMM);
+        entry(
+            "syscall",
+            Syscall,
+            if sbpf_version == SBPFVersion::V1 {
+                ebpf::CALL_IMM
+            } else {
+                ebpf::SYSCALL
+            },
+        );
         entry("call", CallImm, ebpf::CALL_IMM);
         entry("callx", CallReg, ebpf::CALL_REG);
         entry("lddw", LoadDwImm, ebpf::LD_DW_IMM);
@@ -450,6 +458,7 @@ pub fn assemble<C: ContextObject>(
                                 0,
                                 ebpf::hash_symbol_name(label.as_bytes()) as i32 as i64,
                             ),
+                            (Syscall, [Integer(imm)]) => insn(opc, 0, 0, 0, *imm),
                             (CallImm, [Label(label)]) => {
                                 let label: &str = label;
                                 let target_pc = *labels

diff --git a/src/disassembler.rs b/src/disassembler.rs
@@ -265,14 +265,7 @@ pub fn disassemble_instruction<C: ContextObject>(
         ebpf::JSLE_IMM   => { name = "jsle"; desc = jmp_imm_str(name, insn, cfg_nodes); },
         ebpf::JSLE_REG   => { name = "jsle"; desc = jmp_reg_str(name, insn, cfg_nodes); },
         ebpf::CALL_IMM   => {
-            let mut function_name = None;
-            if sbpf_version.static_syscalls() {
-                if insn.src != 0 {
-                    function_name = Some(resolve_label(cfg_nodes, insn.imm as usize).to_string());
-                }
-            } else {
-                function_name = function_registry.lookup_by_key(insn.imm as u32).map(|(function_name, _)| String::from_utf8_lossy(function_name).to_string());
-            }
+            let function_name = function_registry.lookup_by_key(insn.imm as u32).map(|(function_name, _)| String::from_utf8_lossy(function_name).to_string());
             let function_name = if let Some(function_name) = function_name {
                 name = "call";
                 function_name
@@ -284,9 +277,9 @@ pub fn disassemble_instruction<C: ContextObject>(
         },
         ebpf::CALL_REG   => { name = "callx"; desc = format!("{} r{}", name, if sbpf_version.callx_uses_src_reg() { insn.src } else { insn.imm as u8 }); },
         ebpf::EXIT
-        | ebpf::RETURN   if !sbpf_version.static_syscalls() => { name = "exit"; desc = name.to_string(); },
-        ebpf::EXIT
-        | ebpf::RETURN   if sbpf_version.static_syscalls() =>  { name = "return"; desc = name.to_string(); },
+        | ebpf::RETURN if !sbpf_version.static_syscalls() => { name = "exit"; desc = name.to_string(); },
+        ebpf::RETURN   if sbpf_version.static_syscalls() =>  { name = "return"; desc = name.to_string(); },
+        ebpf::SYSCALL  if sbpf_version.static_syscalls() =>  { desc = format!("syscall {}", insn.imm); },
 
         _                => { name = "unknown"; desc = format!("{} opcode={:#x}", name, insn.opc); },
     };

diff --git a/src/ebpf.rs b/src/ebpf.rs
@@ -195,8 +195,10 @@ pub const BPF_JSGT: u8 = 0x60;
 pub const BPF_JSGE: u8 = 0x70;
 /// BPF JMP operation code: syscall function call.
 pub const BPF_CALL: u8 = 0x80;
-/// BPF JMP operation code: return from program.
+/// BPF JMP operation code: return from program (V1).
 pub const BPF_EXIT: u8 = 0x90;
+/// BPF JMP operation code: static syscall (V2).
+pub const BPF_SYSCALL: u8 = 0x90;
 /// BPF JMP operation code: jump if lower than.
 pub const BPF_JLT: u8 = 0xa0;
 /// BPF JMP operation code: jump if lower or equal.
@@ -484,6 +486,8 @@ pub const CALL_REG: u8 = BPF_JMP | BPF_X | BPF_CALL;
 pub const EXIT: u8 = BPF_JMP | BPF_EXIT;
 /// BPF opcode: `return` /// `return r0`. /// Valid only for SBPFv2
 pub const RETURN: u8 = BPF_JMP | BPF_X | BPF_EXIT;
+/// BPF opcode: `syscall` /// `syscall imm`. /// Valid only for SBPFv2
+pub const SYSCALL: u8 = BPF_JMP | BPF_SYSCALL;
 
 // Used in JIT
 /// Mask to extract the operation class from an operation code.

diff --git a/src/interpreter.rs b/src/interpreter.rs
@@ -526,7 +526,8 @@ impl<'a, 'b, C: ContextObject> Interpreter<'a, 'b, C> {
 
             // Do not delegate the check to the verifier, since self.registered functions can be
             // changed after the program has been verified.
-            ebpf::CALL_IMM   => {
+            ebpf::CALL_IMM
+            | ebpf::SYSCALL if insn.opc == ebpf::CALL_IMM || self.executable.get_sbpf_version().static_syscalls() => {
                 let mut resolved = false;
                 let (external, internal) = if self.executable.get_sbpf_version().static_syscalls() {
                     (insn.src == 0, insn.src != 0)

diff --git a/src/jit.rs b/src/jit.rs
@@ -705,7 +705,8 @@ impl<'a, C: ContextObject> JitCompiler<'a, C> {
                 ebpf::JSLT_REG   => self.emit_conditional_branch_reg(0x8c, false, src, dst, target_pc),
                 ebpf::JSLE_IMM   => self.emit_conditional_branch_imm(0x8e, false, insn.imm, dst, target_pc),
                 ebpf::JSLE_REG   => self.emit_conditional_branch_reg(0x8e, false, src, dst, target_pc),
-                ebpf::CALL_IMM   => {
+                ebpf::CALL_IMM | ebpf::SYSCALL
+                if insn.opc == ebpf::CALL_IMM || self.executable.get_sbpf_version().static_syscalls() => {
                     // For JIT, external functions MUST be registered at compile time.
 
                     let mut resolved = false;

diff --git a/src/verifier.rs b/src/verifier.rs
@@ -392,6 +392,7 @@ impl Verifier for RequisiteVerifier {
                 ebpf::CALL_REG   => { check_callx_register(&insn, insn_ptr, sbpf_version)?; },
                 ebpf::EXIT       if !sbpf_version.static_syscalls()   => {},
                 ebpf::RETURN     if sbpf_version.static_syscalls()    => {},
+                ebpf::SYSCALL    if sbpf_version.static_syscalls()    => {},
 
                 _                => {
                     return Err(VerifierError::UnknownOpCode(insn.opc, insn_ptr));

diff --git a/tests/assembler.rs b/tests/assembler.rs
@@ -71,6 +71,19 @@ fn test_exit() {
     );
 }
 
+#[test]
+fn test_static_syscall() {
+    let config = Config {
+        enabled_sbpf_versions: SBPFVersion::V2..=SBPFVersion::V2,
+        ..Config::default()
+    };
+
+    assert_eq!(
+        asm_with_config("syscall 3", config),
+        Ok(vec![insn(0, ebpf::SYSCALL, 0, 0, 0, 3)])
+    );
+}
+
 #[test]
 fn test_return() {
     let config = Config {

diff --git a/tests/disassembler.rs b/tests/disassembler.rs
@@ -60,6 +60,15 @@ fn test_return() {
     disasm!("entrypoint:\n    return\n", config);
 }
 
+#[test]
+fn test_static_syscall() {
+    let config = Config {
+        enabled_sbpf_versions: SBPFVersion::V2..=SBPFVersion::V2,
+        ..Config::default()
+    };
+    disasm!("entrypoint:\n    syscall 5\n", config);
+}
+
 // Example for InstructionType::AluBinary.
 #[test]
 fn test_add64() {

diff --git a/tests/verifier.rs b/tests/verifier.rs
@@ -431,7 +431,7 @@ fn return_instr() {
     for sbpf_version in [SBPFVersion::V1, SBPFVersion::V2] {
         let prog = &[
             0xbf, 0x00, 0x00, 0x00, 0x02, 0x00, 0x00, 0x00, // mov64 r0, 2
-            0x95, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // exit
+            0x95, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // exit (v1), syscall (v2)
             0x9d, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // return
         ];
 
@@ -444,7 +444,7 @@ fn return_instr() {
         .unwrap();
         let result = executable.verify::<RequisiteVerifier>();
         if sbpf_version == SBPFVersion::V2 {
-            assert_error!(result, "VerifierError(UnknownOpCode(149, 1))");
+            assert!(result.is_ok());
         } else {
             assert_error!(result, "VerifierError(UnknownOpCode(157, 2))");
         }