Handle thread_get_state errors

proctl/registers_darwin_amd64.go

@@ -2,6 +2,7 @@ package proctl
 
 // #include "threads_darwin.h"
 import "C"
+import "fmt"
 
 type Regs struct {
 	pc, sp uint64
@@ -21,7 +22,11 @@ func (r *Regs) SetPC(thread *ThreadContext, pc uint64) error {
 }
 
 func registers(thread *ThreadContext) (Registers, error) {
-	state := C.get_registers(C.mach_port_name_t(thread.os.thread_act))
+	var state C.x86_thread_state64_t
+	kret := C.get_registers(C.mach_port_name_t(thread.os.thread_act), &state)
+	if kret != C.KERN_SUCCESS {
+		return nil, fmt.Errorf("could not get registers")
+	}
 	regs := &Regs{pc: uint64(state.__rip), sp: uint64(state.__rsp)}
 	return regs, nil
 }

proctl/threads_darwin.c

@@ -37,18 +37,13 @@ read_memory(mach_port_name_t task, mach_vm_address_t addr, void *d, mach_msg_typ
 	return count;
 }
 
-x86_thread_state64_t
-get_registers(mach_port_name_t task) {
+kern_return_t
+get_registers(mach_port_name_t task, x86_thread_state64_t *state) {
 	kern_return_t kret;
-	x86_thread_state64_t state;
 	mach_msg_type_number_t stateCount = x86_THREAD_STATE64_COUNT;
 
 	// TODO(dp) - possible memory leak - vm_deallocate state
-	kret = thread_get_state(task, x86_THREAD_STATE64, (thread_state_t)&state, &stateCount);
-	if (kret != KERN_SUCCESS) printf("SOMETHING WENT WRONG-------------- %d\n", kret);
-	if (kret == KERN_INVALID_ARGUMENT) puts("INAVLID ARGUMENT");
-
-	return state;
+	return thread_get_state(task, x86_THREAD_STATE64, (thread_state_t)state, &stateCount);
 }
 
 // TODO(dp) this should return kret instead of void

proctl/threads_darwin.h

@@ -10,8 +10,8 @@ write_memory(mach_port_name_t, mach_vm_address_t, void *, mach_msg_type_number_t
 int
 read_memory(mach_port_name_t, mach_vm_address_t, void *, mach_msg_type_number_t);
 
-x86_thread_state64_t
-get_registers(mach_port_name_t);
+kern_return_t
+get_registers(mach_port_name_t, x86_thread_state64_t*);
 
 void
 set_pc(thread_act_t, uint64_t);