Add cpu builtin

README.md

@@ -98,6 +98,7 @@ Variables:
 - `uid` - User ID
 - `gid` - Group ID
 - `nsecs` - Nanosecond timestamp
+- `cpu` - Processor ID
 - `comm` - Process name
 - `stack` - Kernel stack trace
 - `ustack` - User stack trace

src/codegen_llvm.cpp

@@ -60,6 +60,10 @@ void CodegenLLVM::visit(Builtin &builtin)
       expr_ = b_.CreateLShr(uidgid, 32);
     }
   }
+  else if (builtin.ident == "cpu")
+  {
+    expr_ = b_.CreateGetCpuId();
+  }
   else if (builtin.ident == "comm")
   {
     AllocaInst *buf = b_.CreateAllocaBPF(builtin.type, "comm");

src/irbuilderbpf.cpp

@@ -258,6 +258,19 @@ CallInst *IRBuilderBPF::CreateGetUidGid()
   return CreateCall(getuidgid_func, {}, "get_uid_gid");
 }
 
+CallInst *IRBuilderBPF::CreateGetCpuId()
+{
+  // u32 bpf_raw_smp_processor_id(void)
+  // Return: SMP processor ID
+  FunctionType *getcpuid_func_type = FunctionType::get(getInt64Ty(), false);
+  PointerType *getcpuid_func_ptr_type = PointerType::get(getcpuid_func_type, 0);
+  Constant *getcpuid_func = ConstantExpr::getCast(
+      Instruction::IntToPtr,
+      getInt64(BPF_FUNC_get_smp_processor_id),
+      getcpuid_func_ptr_type);
+  return CreateCall(getcpuid_func, {}, "get_cpu_id");
+}
+
 CallInst *IRBuilderBPF::CreateGetStackId(Value *ctx, bool ustack)
 {
   Value *map_ptr = CreateBpfPseudoCall(bpftrace_.stackid_map_->mapfd_);

src/irbuilderbpf.h

@@ -32,6 +32,7 @@ public:
   CallInst   *CreateGetNs();
   CallInst   *CreateGetPidTgid();
   CallInst   *CreateGetUidGid();
+  CallInst   *CreateGetCpuId();
   CallInst   *CreateGetStackId(Value *ctx, bool ustack);
   void        CreateGetCurrentComm(AllocaInst *buf, size_t size);
 

src/semantic_analyser.cpp

@@ -28,6 +28,7 @@ void SemanticAnalyser::visit(Builtin &builtin)
       builtin.ident == "tid" ||
       builtin.ident == "uid" ||
       builtin.ident == "gid" ||
+      builtin.ident == "cpu" ||
       builtin.ident == "retval") {
     builtin.type = SizedType(Type::integer, 8);
   }