Fix - callx (#583)

* adds test

* fix callx

src/interpreter.rs

@@ -449,10 +449,7 @@ impl<'a, 'b, C: ContextObject> Interpreter<'a, 'b, C> {
                 if !self.push_frame(config) {
                     return false;
                 }
-                if target_pc < self.program_vm_addr {
-                    throw_error!(self, EbpfError::CallOutsideTextSegment);
-                }
-                check_pc!(self, next_pc, (target_pc - self.program_vm_addr) / ebpf::INSN_SIZE as u64);
+                check_pc!(self, next_pc, target_pc.wrapping_sub(self.program_vm_addr) / ebpf::INSN_SIZE as u64);
                 if self.executable.get_sbpf_version().static_syscalls() && self.executable.get_function_registry().lookup_by_key(next_pc as u32).is_none() {
                     self.vm.due_insn_count += 1;
                     self.reg[11] = next_pc;

src/jit.rs

@@ -1463,21 +1463,16 @@ impl<'a, C: ContextObject> JitCompiler<'a, C> {
 
         // Routine for emit_internal_call(Value::Register())
         self.set_anchor(ANCHOR_ANCHOR_INTERNAL_FUNCTION_CALL_REG);
+        // Calculate offset relative to instruction_addresses
+        self.emit_ins(X86Instruction::load_immediate(OperandSize::S64, REGISTER_MAP[FRAME_PTR_REG], self.program_vm_addr as i64));
+        self.emit_ins(X86Instruction::alu(OperandSize::S64, 0x29, REGISTER_MAP[FRAME_PTR_REG], REGISTER_MAP[0], 0, None)); // RAX -= self.program_vm_addr;
         // Force alignment of RAX
         self.emit_ins(X86Instruction::alu(OperandSize::S64, 0x81, 4, REGISTER_MAP[0], !(INSN_SIZE as i64 - 1), None)); // RAX &= !(INSN_SIZE - 1);
-        // Upper bound check
-        // if(RAX >= self.program_vm_addr + number_of_instructions * INSN_SIZE) throw CALL_OUTSIDE_TEXT_SEGMENT;
+        // Bound check
+        // if(RAX >= number_of_instructions * INSN_SIZE) throw CALL_OUTSIDE_TEXT_SEGMENT;
         let number_of_instructions = self.result.pc_section.len();
-        self.emit_ins(X86Instruction::load_immediate(OperandSize::S64, REGISTER_MAP[FRAME_PTR_REG], self.program_vm_addr as i64 + (number_of_instructions * INSN_SIZE) as i64));
-        self.emit_ins(X86Instruction::cmp(OperandSize::S64, REGISTER_MAP[FRAME_PTR_REG], REGISTER_MAP[0], None));
+        self.emit_ins(X86Instruction::cmp_immediate(OperandSize::S64, REGISTER_MAP[0], (number_of_instructions * INSN_SIZE) as i64, None));
         self.emit_ins(X86Instruction::conditional_jump_immediate(0x83, self.relative_to_anchor(ANCHOR_CALL_OUTSIDE_TEXT_SEGMENT, 6)));
-        // Lower bound check
-        // if(RAX < self.program_vm_addr) throw CALL_OUTSIDE_TEXT_SEGMENT;
-        self.emit_ins(X86Instruction::load_immediate(OperandSize::S64, REGISTER_MAP[FRAME_PTR_REG], self.program_vm_addr as i64));
-        self.emit_ins(X86Instruction::cmp(OperandSize::S64, REGISTER_MAP[FRAME_PTR_REG], REGISTER_MAP[0], None));
-        self.emit_ins(X86Instruction::conditional_jump_immediate(0x82, self.relative_to_anchor(ANCHOR_CALL_OUTSIDE_TEXT_SEGMENT, 6)));
-        // Calculate offset relative to instruction_addresses
-        self.emit_ins(X86Instruction::alu(OperandSize::S64, 0x29, REGISTER_MAP[FRAME_PTR_REG], REGISTER_MAP[0], 0, None)); // RAX -= self.program_vm_addr;
         // Calculate the target_pc (dst / INSN_SIZE) to update REGISTER_INSTRUCTION_METER
         // and as target pc for potential ANCHOR_CALL_UNSUPPORTED_INSTRUCTION
         let shift_amount = INSN_SIZE.trailing_zeros();

tests/elfs/callx_unaligned.rs

@@ -0,0 +1,12 @@
+#![feature(asm_experimental_arch)]
+
+#[no_mangle]
+pub fn entrypoint() {
+    unsafe {
+        std::arch::asm!("
+rsh64 r1, 2
+or64 r1, 0x129
+callx r1
+        ");
+    }
+}

tests/elfs/elfs.sh

@@ -3,7 +3,7 @@
 # Requires Latest release of Solana's custom LLVM
 # https://github.com/solana-labs/platform-tools/releases
 
-TOOLCHAIN=../../../solana/sdk/sbf/dependencies/sbf-tools
+TOOLCHAIN=../../../agave/sdk/sbf/dependencies/platform-tools
 RC_COMMON="$TOOLCHAIN/rust/bin/rustc --target sbf-solana-solana --crate-type lib -C panic=abort -C opt-level=2"
 RC="$RC_COMMON -C target_cpu=sbfv2"
 RC_V1="$RC_COMMON -C target_cpu=generic"
@@ -56,4 +56,7 @@ $LD_V1 -o reloc_64_relative_sbpfv1.so reloc_64_relative.o
 # $RC_V1 -o reloc_64_relative_data.o reloc_64_relative_data.rs
 # $LD_V1 -o reloc_64_relative_data_sbpfv1.so reloc_64_relative_data.o
 
+# $RC_V1 -o callx_unaligned.o callx_unaligned.rs
+# $LD_V1 -o callx_unaligned.so callx_unaligned.o
+
 rm *.o

tests/execution.rs

@@ -2320,6 +2320,17 @@ fn test_err_callx_oob_high() {
     );
 }
 
+#[test]
+fn test_callx_unaligned_text_section() {
+    test_interpreter_and_jit_elf!(
+        "tests/elfs/callx_unaligned.so",
+        [],
+        (),
+        TestContextObject::new(129),
+        ProgramResult::Err(EbpfError::CallDepthExceeded),
+    );
+}
+
 #[test]
 fn test_bpf_to_bpf_depth() {
     for max_call_depth in [20usize, Config::default().max_call_depth] {