1 //===-- RegisterContextFreeBSDKernel_arm64.cpp ----------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #include "RegisterContextFreeBSDKernel_arm64.h"
10 #include "Plugins/Process/Utility/lldb-arm64-register-enums.h"
11 
12 #include "lldb/Target/Process.h"
13 #include "lldb/Target/Thread.h"
14 #include "lldb/Utility/RegisterValue.h"
15 #include "llvm/Support/Endian.h"
16 
17 using namespace lldb;
18 using namespace lldb_private;
19 
20 RegisterContextFreeBSDKernel_arm64::RegisterContextFreeBSDKernel_arm64(
21     Thread &thread, std::unique_ptr<RegisterInfoPOSIX_arm64> register_info_up,
22     lldb::addr_t pcb_addr)
23     : RegisterContextPOSIX_arm64(thread, std::move(register_info_up)),
24       m_pcb_addr(pcb_addr) {}
25 
26 bool RegisterContextFreeBSDKernel_arm64::ReadGPR() { return true; }
27 
28 bool RegisterContextFreeBSDKernel_arm64::ReadFPR() { return true; }
29 
30 bool RegisterContextFreeBSDKernel_arm64::WriteGPR() {
31   assert(0);
32   return false;
33 }
34 
35 bool RegisterContextFreeBSDKernel_arm64::WriteFPR() {
36   assert(0);
37   return false;
38 }
39 
40 bool RegisterContextFreeBSDKernel_arm64::ReadRegister(
41     const RegisterInfo *reg_info, RegisterValue &value) {
42   if (m_pcb_addr == LLDB_INVALID_ADDRESS)
43     return false;
44 
45   struct {
46     llvm::support::ulittle64_t x[30];
47     llvm::support::ulittle64_t lr;
48     llvm::support::ulittle64_t _reserved;
49     llvm::support::ulittle64_t sp;
50   } pcb;
51 
52   Status error;
53   size_t rd =
54       m_thread.GetProcess()->ReadMemory(m_pcb_addr, &pcb, sizeof(pcb), error);
55   if (rd != sizeof(pcb))
56     return false;
57 
58   uint32_t reg = reg_info->kinds[lldb::eRegisterKindLLDB];
59   switch (reg) {
60   case gpr_x0_arm64:
61   case gpr_x1_arm64:
62   case gpr_x2_arm64:
63   case gpr_x3_arm64:
64   case gpr_x4_arm64:
65   case gpr_x5_arm64:
66   case gpr_x6_arm64:
67   case gpr_x7_arm64:
68   case gpr_x8_arm64:
69   case gpr_x9_arm64:
70   case gpr_x10_arm64:
71   case gpr_x11_arm64:
72   case gpr_x12_arm64:
73   case gpr_x13_arm64:
74   case gpr_x14_arm64:
75   case gpr_x15_arm64:
76   case gpr_x16_arm64:
77   case gpr_x17_arm64:
78   case gpr_x18_arm64:
79   case gpr_x19_arm64:
80   case gpr_x20_arm64:
81   case gpr_x21_arm64:
82   case gpr_x22_arm64:
83   case gpr_x23_arm64:
84   case gpr_x24_arm64:
85   case gpr_x25_arm64:
86   case gpr_x26_arm64:
87   case gpr_x27_arm64:
88   case gpr_x28_arm64:
89   case gpr_fp_arm64:
90     static_assert(gpr_fp_arm64 - gpr_x0_arm64 == 29,
91                   "nonconsecutive arm64 register numbers");
92     value = pcb.x[reg - gpr_x0_arm64];
93     break;
94   case gpr_sp_arm64:
95     value = pcb.sp;
96     break;
97   case gpr_pc_arm64:
98     // The pc of crashing thread is stored in lr.
99     value = pcb.lr;
100     break;
101   default:
102     return false;
103   }
104   return true;
105 }
106 
107 bool RegisterContextFreeBSDKernel_arm64::WriteRegister(
108     const RegisterInfo *reg_info, const RegisterValue &value) {
109   return false;
110 }
111