1 //===-- DNBArchImpl.cpp -----------------------------------------*- C++ -*-===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 //  Created by Greg Clayton on 6/25/07.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #if defined(__arm__) || defined(__arm64__) || defined(__aarch64__)
15 
16 #include "MacOSX/arm/DNBArchImpl.h"
17 #include "ARM_DWARF_Registers.h"
18 #include "ARM_ehframe_Registers.h"
19 #include "DNB.h"
20 #include "DNBBreakpoint.h"
21 #include "DNBLog.h"
22 #include "DNBRegisterInfo.h"
23 #include "MacOSX/MachProcess.h"
24 #include "MacOSX/MachThread.h"
25 
26 #include <inttypes.h>
27 #include <sys/sysctl.h>
28 
29 // BCR address match type
30 #define BCR_M_IMVA_MATCH ((uint32_t)(0u << 21))
31 #define BCR_M_CONTEXT_ID_MATCH ((uint32_t)(1u << 21))
32 #define BCR_M_IMVA_MISMATCH ((uint32_t)(2u << 21))
33 #define BCR_M_RESERVED ((uint32_t)(3u << 21))
34 
35 // Link a BVR/BCR or WVR/WCR pair to another
36 #define E_ENABLE_LINKING ((uint32_t)(1u << 20))
37 
38 // Byte Address Select
39 #define BAS_IMVA_PLUS_0 ((uint32_t)(1u << 5))
40 #define BAS_IMVA_PLUS_1 ((uint32_t)(1u << 6))
41 #define BAS_IMVA_PLUS_2 ((uint32_t)(1u << 7))
42 #define BAS_IMVA_PLUS_3 ((uint32_t)(1u << 8))
43 #define BAS_IMVA_0_1 ((uint32_t)(3u << 5))
44 #define BAS_IMVA_2_3 ((uint32_t)(3u << 7))
45 #define BAS_IMVA_ALL ((uint32_t)(0xfu << 5))
46 
47 // Break only in privileged or user mode
48 #define S_RSVD ((uint32_t)(0u << 1))
49 #define S_PRIV ((uint32_t)(1u << 1))
50 #define S_USER ((uint32_t)(2u << 1))
51 #define S_PRIV_USER ((S_PRIV) | (S_USER))
52 
53 #define BCR_ENABLE ((uint32_t)(1u))
54 #define WCR_ENABLE ((uint32_t)(1u))
55 
56 // Watchpoint load/store
57 #define WCR_LOAD ((uint32_t)(1u << 3))
58 #define WCR_STORE ((uint32_t)(1u << 4))
59 
60 // Definitions for the Debug Status and Control Register fields:
61 // [5:2] => Method of debug entry
62 //#define WATCHPOINT_OCCURRED     ((uint32_t)(2u))
63 // I'm seeing this, instead.
64 #define WATCHPOINT_OCCURRED ((uint32_t)(10u))
65 
66 // 0xE120BE70
67 static const uint8_t g_arm_breakpoint_opcode[] = {0x70, 0xBE, 0x20, 0xE1};
68 static const uint8_t g_thumb_breakpoint_opcode[] = {0x70, 0xBE};
69 
70 // A watchpoint may need to be implemented using two watchpoint registers.
71 // e.g. watching an 8-byte region when the device can only watch 4-bytes.
72 //
73 // This stores the lo->hi mappings.  It's safe to initialize to all 0's
74 // since hi > lo and therefore LoHi[i] cannot be 0.
75 static uint32_t LoHi[16] = {0};
76 
77 // ARM constants used during decoding
78 #define REG_RD 0
79 #define LDM_REGLIST 1
80 #define PC_REG 15
81 #define PC_REGLIST_BIT 0x8000
82 
83 // ARM conditions
84 #define COND_EQ 0x0
85 #define COND_NE 0x1
86 #define COND_CS 0x2
87 #define COND_HS 0x2
88 #define COND_CC 0x3
89 #define COND_LO 0x3
90 #define COND_MI 0x4
91 #define COND_PL 0x5
92 #define COND_VS 0x6
93 #define COND_VC 0x7
94 #define COND_HI 0x8
95 #define COND_LS 0x9
96 #define COND_GE 0xA
97 #define COND_LT 0xB
98 #define COND_GT 0xC
99 #define COND_LE 0xD
100 #define COND_AL 0xE
101 #define COND_UNCOND 0xF
102 
103 #define MASK_CPSR_T (1u << 5)
104 #define MASK_CPSR_J (1u << 24)
105 
106 #define MNEMONIC_STRING_SIZE 32
107 #define OPERAND_STRING_SIZE 128
108 
109 // Returns true if the first 16 bit opcode of a thumb instruction indicates
110 // the instruction will be a 32 bit thumb opcode
111 static bool IsThumb32Opcode(uint16_t opcode) {
112   if (((opcode & 0xE000) == 0xE000) && (opcode & 0x1800))
113     return true;
114   return false;
115 }
116 
117 void DNBArchMachARM::Initialize() {
118   DNBArchPluginInfo arch_plugin_info = {
119       CPU_TYPE_ARM, DNBArchMachARM::Create, DNBArchMachARM::GetRegisterSetInfo,
120       DNBArchMachARM::SoftwareBreakpointOpcode};
121 
122   // Register this arch plug-in with the main protocol class
123   DNBArchProtocol::RegisterArchPlugin(arch_plugin_info);
124 }
125 
126 DNBArchProtocol *DNBArchMachARM::Create(MachThread *thread) {
127   DNBArchMachARM *obj = new DNBArchMachARM(thread);
128   return obj;
129 }
130 
131 const uint8_t *DNBArchMachARM::SoftwareBreakpointOpcode(nub_size_t byte_size) {
132   switch (byte_size) {
133   case 2:
134     return g_thumb_breakpoint_opcode;
135   case 4:
136     return g_arm_breakpoint_opcode;
137   }
138   return NULL;
139 }
140 
141 uint32_t DNBArchMachARM::GetCPUType() { return CPU_TYPE_ARM; }
142 
143 uint64_t DNBArchMachARM::GetPC(uint64_t failValue) {
144   // Get program counter
145   if (GetGPRState(false) == KERN_SUCCESS)
146     return m_state.context.gpr.__pc;
147   return failValue;
148 }
149 
150 kern_return_t DNBArchMachARM::SetPC(uint64_t value) {
151   // Get program counter
152   kern_return_t err = GetGPRState(false);
153   if (err == KERN_SUCCESS) {
154     m_state.context.gpr.__pc = (uint32_t)value;
155     err = SetGPRState();
156   }
157   return err == KERN_SUCCESS;
158 }
159 
160 uint64_t DNBArchMachARM::GetSP(uint64_t failValue) {
161   // Get stack pointer
162   if (GetGPRState(false) == KERN_SUCCESS)
163     return m_state.context.gpr.__sp;
164   return failValue;
165 }
166 
167 kern_return_t DNBArchMachARM::GetGPRState(bool force) {
168   int set = e_regSetGPR;
169   // Check if we have valid cached registers
170   if (!force && m_state.GetError(set, Read) == KERN_SUCCESS)
171     return KERN_SUCCESS;
172 
173   // Read the registers from our thread
174   mach_msg_type_number_t count = ARM_THREAD_STATE_COUNT;
175   kern_return_t kret =
176       ::thread_get_state(m_thread->MachPortNumber(), ARM_THREAD_STATE,
177                          (thread_state_t)&m_state.context.gpr, &count);
178   uint32_t *r = &m_state.context.gpr.__r[0];
179   DNBLogThreadedIf(
180       LOG_THREAD, "thread_get_state(0x%4.4x, %u, &gpr, %u) => 0x%8.8x (count = "
181                   "%u) regs r0=%8.8x r1=%8.8x r2=%8.8x r3=%8.8x r4=%8.8x "
182                   "r5=%8.8x r6=%8.8x r7=%8.8x r8=%8.8x r9=%8.8x r10=%8.8x "
183                   "r11=%8.8x s12=%8.8x sp=%8.8x lr=%8.8x pc=%8.8x cpsr=%8.8x",
184       m_thread->MachPortNumber(), ARM_THREAD_STATE, ARM_THREAD_STATE_COUNT,
185       kret, count, r[0], r[1], r[2], r[3], r[4], r[5], r[6], r[7], r[8], r[9],
186       r[10], r[11], r[12], r[13], r[14], r[15], r[16]);
187   m_state.SetError(set, Read, kret);
188   return kret;
189 }
190 
191 kern_return_t DNBArchMachARM::GetVFPState(bool force) {
192   int set = e_regSetVFP;
193   // Check if we have valid cached registers
194   if (!force && m_state.GetError(set, Read) == KERN_SUCCESS)
195     return KERN_SUCCESS;
196 
197   kern_return_t kret;
198 
199 #if defined(__arm64__) || defined(__aarch64__)
200   // Read the registers from our thread
201   mach_msg_type_number_t count = ARM_NEON_STATE_COUNT;
202   kret = ::thread_get_state(m_thread->MachPortNumber(), ARM_NEON_STATE,
203                             (thread_state_t)&m_state.context.vfp, &count);
204   if (DNBLogEnabledForAny(LOG_THREAD)) {
205     DNBLogThreaded(
206         "thread_get_state(0x%4.4x, %u, &vfp, %u) => 0x%8.8x (count = %u) regs"
207         "\n   q0  = 0x%16.16llx%16.16llx"
208         "\n   q1  = 0x%16.16llx%16.16llx"
209         "\n   q2  = 0x%16.16llx%16.16llx"
210         "\n   q3  = 0x%16.16llx%16.16llx"
211         "\n   q4  = 0x%16.16llx%16.16llx"
212         "\n   q5  = 0x%16.16llx%16.16llx"
213         "\n   q6  = 0x%16.16llx%16.16llx"
214         "\n   q7  = 0x%16.16llx%16.16llx"
215         "\n   q8  = 0x%16.16llx%16.16llx"
216         "\n   q9  = 0x%16.16llx%16.16llx"
217         "\n   q10 = 0x%16.16llx%16.16llx"
218         "\n   q11 = 0x%16.16llx%16.16llx"
219         "\n   q12 = 0x%16.16llx%16.16llx"
220         "\n   q13 = 0x%16.16llx%16.16llx"
221         "\n   q14 = 0x%16.16llx%16.16llx"
222         "\n   q15 = 0x%16.16llx%16.16llx"
223         "\n  fpsr = 0x%8.8x"
224         "\n  fpcr = 0x%8.8x\n\n",
225         m_thread->MachPortNumber(), ARM_NEON_STATE, ARM_NEON_STATE_COUNT, kret,
226         count, ((uint64_t *)&m_state.context.vfp.__v[0])[0],
227         ((uint64_t *)&m_state.context.vfp.__v[0])[1],
228         ((uint64_t *)&m_state.context.vfp.__v[1])[0],
229         ((uint64_t *)&m_state.context.vfp.__v[1])[1],
230         ((uint64_t *)&m_state.context.vfp.__v[2])[0],
231         ((uint64_t *)&m_state.context.vfp.__v[2])[1],
232         ((uint64_t *)&m_state.context.vfp.__v[3])[0],
233         ((uint64_t *)&m_state.context.vfp.__v[3])[1],
234         ((uint64_t *)&m_state.context.vfp.__v[4])[0],
235         ((uint64_t *)&m_state.context.vfp.__v[4])[1],
236         ((uint64_t *)&m_state.context.vfp.__v[5])[0],
237         ((uint64_t *)&m_state.context.vfp.__v[5])[1],
238         ((uint64_t *)&m_state.context.vfp.__v[6])[0],
239         ((uint64_t *)&m_state.context.vfp.__v[6])[1],
240         ((uint64_t *)&m_state.context.vfp.__v[7])[0],
241         ((uint64_t *)&m_state.context.vfp.__v[7])[1],
242         ((uint64_t *)&m_state.context.vfp.__v[8])[0],
243         ((uint64_t *)&m_state.context.vfp.__v[8])[1],
244         ((uint64_t *)&m_state.context.vfp.__v[9])[0],
245         ((uint64_t *)&m_state.context.vfp.__v[9])[1],
246         ((uint64_t *)&m_state.context.vfp.__v[10])[0],
247         ((uint64_t *)&m_state.context.vfp.__v[10])[1],
248         ((uint64_t *)&m_state.context.vfp.__v[11])[0],
249         ((uint64_t *)&m_state.context.vfp.__v[11])[1],
250         ((uint64_t *)&m_state.context.vfp.__v[12])[0],
251         ((uint64_t *)&m_state.context.vfp.__v[12])[1],
252         ((uint64_t *)&m_state.context.vfp.__v[13])[0],
253         ((uint64_t *)&m_state.context.vfp.__v[13])[1],
254         ((uint64_t *)&m_state.context.vfp.__v[14])[0],
255         ((uint64_t *)&m_state.context.vfp.__v[14])[1],
256         ((uint64_t *)&m_state.context.vfp.__v[15])[0],
257         ((uint64_t *)&m_state.context.vfp.__v[15])[1],
258         m_state.context.vfp.__fpsr, m_state.context.vfp.__fpcr);
259   }
260 #else
261   // Read the registers from our thread
262   mach_msg_type_number_t count = ARM_VFP_STATE_COUNT;
263   kret = ::thread_get_state(m_thread->MachPortNumber(), ARM_VFP_STATE,
264                             (thread_state_t)&m_state.context.vfp, &count);
265 
266   if (DNBLogEnabledForAny(LOG_THREAD)) {
267     uint32_t *r = &m_state.context.vfp.__r[0];
268     DNBLogThreaded(
269         "thread_get_state(0x%4.4x, %u, &gpr, %u) => 0x%8.8x (count => %u)",
270         m_thread->MachPortNumber(), ARM_THREAD_STATE, ARM_THREAD_STATE_COUNT,
271         kret, count);
272     DNBLogThreaded("   s0=%8.8x  s1=%8.8x  s2=%8.8x  s3=%8.8x  s4=%8.8x  "
273                    "s5=%8.8x  s6=%8.8x  s7=%8.8x",
274                    r[0], r[1], r[2], r[3], r[4], r[5], r[6], r[7]);
275     DNBLogThreaded("   s8=%8.8x  s9=%8.8x s10=%8.8x s11=%8.8x s12=%8.8x "
276                    "s13=%8.8x s14=%8.8x s15=%8.8x",
277                    r[8], r[9], r[10], r[11], r[12], r[13], r[14], r[15]);
278     DNBLogThreaded("  s16=%8.8x s17=%8.8x s18=%8.8x s19=%8.8x s20=%8.8x "
279                    "s21=%8.8x s22=%8.8x s23=%8.8x",
280                    r[16], r[17], r[18], r[19], r[20], r[21], r[22], r[23]);
281     DNBLogThreaded("  s24=%8.8x s25=%8.8x s26=%8.8x s27=%8.8x s28=%8.8x "
282                    "s29=%8.8x s30=%8.8x s31=%8.8x",
283                    r[24], r[25], r[26], r[27], r[28], r[29], r[30], r[31]);
284     DNBLogThreaded("  s32=%8.8x s33=%8.8x s34=%8.8x s35=%8.8x s36=%8.8x "
285                    "s37=%8.8x s38=%8.8x s39=%8.8x",
286                    r[32], r[33], r[34], r[35], r[36], r[37], r[38], r[39]);
287     DNBLogThreaded("  s40=%8.8x s41=%8.8x s42=%8.8x s43=%8.8x s44=%8.8x "
288                    "s45=%8.8x s46=%8.8x s47=%8.8x",
289                    r[40], r[41], r[42], r[43], r[44], r[45], r[46], r[47]);
290     DNBLogThreaded("  s48=%8.8x s49=%8.8x s50=%8.8x s51=%8.8x s52=%8.8x "
291                    "s53=%8.8x s54=%8.8x s55=%8.8x",
292                    r[48], r[49], r[50], r[51], r[52], r[53], r[54], r[55]);
293     DNBLogThreaded("  s56=%8.8x s57=%8.8x s58=%8.8x s59=%8.8x s60=%8.8x "
294                    "s61=%8.8x s62=%8.8x s63=%8.8x fpscr=%8.8x",
295                    r[56], r[57], r[58], r[59], r[60], r[61], r[62], r[63],
296                    r[64]);
297   }
298 
299 #endif
300   m_state.SetError(set, Read, kret);
301   return kret;
302 }
303 
304 kern_return_t DNBArchMachARM::GetEXCState(bool force) {
305   int set = e_regSetEXC;
306   // Check if we have valid cached registers
307   if (!force && m_state.GetError(set, Read) == KERN_SUCCESS)
308     return KERN_SUCCESS;
309 
310   // Read the registers from our thread
311   mach_msg_type_number_t count = ARM_EXCEPTION_STATE_COUNT;
312   kern_return_t kret =
313       ::thread_get_state(m_thread->MachPortNumber(), ARM_EXCEPTION_STATE,
314                          (thread_state_t)&m_state.context.exc, &count);
315   m_state.SetError(set, Read, kret);
316   return kret;
317 }
318 
319 static void DumpDBGState(const DNBArchMachARM::DBG &dbg) {
320   uint32_t i = 0;
321   for (i = 0; i < 16; i++) {
322     DNBLogThreadedIf(LOG_STEP, "BVR%-2u/BCR%-2u = { 0x%8.8x, 0x%8.8x } "
323                                "WVR%-2u/WCR%-2u = { 0x%8.8x, 0x%8.8x }",
324                      i, i, dbg.__bvr[i], dbg.__bcr[i], i, i, dbg.__wvr[i],
325                      dbg.__wcr[i]);
326   }
327 }
328 
329 kern_return_t DNBArchMachARM::GetDBGState(bool force) {
330   int set = e_regSetDBG;
331 
332   // Check if we have valid cached registers
333   if (!force && m_state.GetError(set, Read) == KERN_SUCCESS)
334     return KERN_SUCCESS;
335 
336 // Read the registers from our thread
337 #if defined(ARM_DEBUG_STATE32) && (defined(__arm64__) || defined(__aarch64__))
338   mach_msg_type_number_t count = ARM_DEBUG_STATE32_COUNT;
339   kern_return_t kret =
340       ::thread_get_state(m_thread->MachPortNumber(), ARM_DEBUG_STATE32,
341                          (thread_state_t)&m_state.dbg, &count);
342 #else
343   mach_msg_type_number_t count = ARM_DEBUG_STATE_COUNT;
344   kern_return_t kret =
345       ::thread_get_state(m_thread->MachPortNumber(), ARM_DEBUG_STATE,
346                          (thread_state_t)&m_state.dbg, &count);
347 #endif
348   m_state.SetError(set, Read, kret);
349 
350   return kret;
351 }
352 
353 kern_return_t DNBArchMachARM::SetGPRState() {
354   int set = e_regSetGPR;
355   kern_return_t kret = ::thread_set_state(
356       m_thread->MachPortNumber(), ARM_THREAD_STATE,
357       (thread_state_t)&m_state.context.gpr, ARM_THREAD_STATE_COUNT);
358   m_state.SetError(set, Write,
359                    kret); // Set the current write error for this register set
360   m_state.InvalidateRegisterSetState(set); // Invalidate the current register
361                                            // state in case registers are read
362                                            // back differently
363   return kret;                             // Return the error code
364 }
365 
366 kern_return_t DNBArchMachARM::SetVFPState() {
367   int set = e_regSetVFP;
368   kern_return_t kret;
369   mach_msg_type_number_t count;
370 
371 #if defined(__arm64__) || defined(__aarch64__)
372   count = ARM_NEON_STATE_COUNT;
373   kret = ::thread_set_state(m_thread->MachPortNumber(), ARM_NEON_STATE,
374                             (thread_state_t)&m_state.context.vfp, count);
375 #else
376   count = ARM_VFP_STATE_COUNT;
377   kret = ::thread_set_state(m_thread->MachPortNumber(), ARM_VFP_STATE,
378                             (thread_state_t)&m_state.context.vfp, count);
379 #endif
380 
381 #if defined(__arm64__) || defined(__aarch64__)
382   if (DNBLogEnabledForAny(LOG_THREAD)) {
383     DNBLogThreaded(
384         "thread_set_state(0x%4.4x, %u, &vfp, %u) => 0x%8.8x (count = %u) regs"
385         "\n   q0  = 0x%16.16llx%16.16llx"
386         "\n   q1  = 0x%16.16llx%16.16llx"
387         "\n   q2  = 0x%16.16llx%16.16llx"
388         "\n   q3  = 0x%16.16llx%16.16llx"
389         "\n   q4  = 0x%16.16llx%16.16llx"
390         "\n   q5  = 0x%16.16llx%16.16llx"
391         "\n   q6  = 0x%16.16llx%16.16llx"
392         "\n   q7  = 0x%16.16llx%16.16llx"
393         "\n   q8  = 0x%16.16llx%16.16llx"
394         "\n   q9  = 0x%16.16llx%16.16llx"
395         "\n   q10 = 0x%16.16llx%16.16llx"
396         "\n   q11 = 0x%16.16llx%16.16llx"
397         "\n   q12 = 0x%16.16llx%16.16llx"
398         "\n   q13 = 0x%16.16llx%16.16llx"
399         "\n   q14 = 0x%16.16llx%16.16llx"
400         "\n   q15 = 0x%16.16llx%16.16llx"
401         "\n  fpsr = 0x%8.8x"
402         "\n  fpcr = 0x%8.8x\n\n",
403         m_thread->MachPortNumber(), ARM_NEON_STATE, ARM_NEON_STATE_COUNT, kret,
404         count, ((uint64_t *)&m_state.context.vfp.__v[0])[0],
405         ((uint64_t *)&m_state.context.vfp.__v[0])[1],
406         ((uint64_t *)&m_state.context.vfp.__v[1])[0],
407         ((uint64_t *)&m_state.context.vfp.__v[1])[1],
408         ((uint64_t *)&m_state.context.vfp.__v[2])[0],
409         ((uint64_t *)&m_state.context.vfp.__v[2])[1],
410         ((uint64_t *)&m_state.context.vfp.__v[3])[0],
411         ((uint64_t *)&m_state.context.vfp.__v[3])[1],
412         ((uint64_t *)&m_state.context.vfp.__v[4])[0],
413         ((uint64_t *)&m_state.context.vfp.__v[4])[1],
414         ((uint64_t *)&m_state.context.vfp.__v[5])[0],
415         ((uint64_t *)&m_state.context.vfp.__v[5])[1],
416         ((uint64_t *)&m_state.context.vfp.__v[6])[0],
417         ((uint64_t *)&m_state.context.vfp.__v[6])[1],
418         ((uint64_t *)&m_state.context.vfp.__v[7])[0],
419         ((uint64_t *)&m_state.context.vfp.__v[7])[1],
420         ((uint64_t *)&m_state.context.vfp.__v[8])[0],
421         ((uint64_t *)&m_state.context.vfp.__v[8])[1],
422         ((uint64_t *)&m_state.context.vfp.__v[9])[0],
423         ((uint64_t *)&m_state.context.vfp.__v[9])[1],
424         ((uint64_t *)&m_state.context.vfp.__v[10])[0],
425         ((uint64_t *)&m_state.context.vfp.__v[10])[1],
426         ((uint64_t *)&m_state.context.vfp.__v[11])[0],
427         ((uint64_t *)&m_state.context.vfp.__v[11])[1],
428         ((uint64_t *)&m_state.context.vfp.__v[12])[0],
429         ((uint64_t *)&m_state.context.vfp.__v[12])[1],
430         ((uint64_t *)&m_state.context.vfp.__v[13])[0],
431         ((uint64_t *)&m_state.context.vfp.__v[13])[1],
432         ((uint64_t *)&m_state.context.vfp.__v[14])[0],
433         ((uint64_t *)&m_state.context.vfp.__v[14])[1],
434         ((uint64_t *)&m_state.context.vfp.__v[15])[0],
435         ((uint64_t *)&m_state.context.vfp.__v[15])[1],
436         m_state.context.vfp.__fpsr, m_state.context.vfp.__fpcr);
437   }
438 #else
439   if (DNBLogEnabledForAny(LOG_THREAD)) {
440     uint32_t *r = &m_state.context.vfp.__r[0];
441     DNBLogThreaded(
442         "thread_get_state(0x%4.4x, %u, &gpr, %u) => 0x%8.8x (count => %u)",
443         m_thread->MachPortNumber(), ARM_THREAD_STATE, ARM_THREAD_STATE_COUNT,
444         kret, count);
445     DNBLogThreaded("   s0=%8.8x  s1=%8.8x  s2=%8.8x  s3=%8.8x  s4=%8.8x  "
446                    "s5=%8.8x  s6=%8.8x  s7=%8.8x",
447                    r[0], r[1], r[2], r[3], r[4], r[5], r[6], r[7]);
448     DNBLogThreaded("   s8=%8.8x  s9=%8.8x s10=%8.8x s11=%8.8x s12=%8.8x "
449                    "s13=%8.8x s14=%8.8x s15=%8.8x",
450                    r[8], r[9], r[10], r[11], r[12], r[13], r[14], r[15]);
451     DNBLogThreaded("  s16=%8.8x s17=%8.8x s18=%8.8x s19=%8.8x s20=%8.8x "
452                    "s21=%8.8x s22=%8.8x s23=%8.8x",
453                    r[16], r[17], r[18], r[19], r[20], r[21], r[22], r[23]);
454     DNBLogThreaded("  s24=%8.8x s25=%8.8x s26=%8.8x s27=%8.8x s28=%8.8x "
455                    "s29=%8.8x s30=%8.8x s31=%8.8x",
456                    r[24], r[25], r[26], r[27], r[28], r[29], r[30], r[31]);
457     DNBLogThreaded("  s32=%8.8x s33=%8.8x s34=%8.8x s35=%8.8x s36=%8.8x "
458                    "s37=%8.8x s38=%8.8x s39=%8.8x",
459                    r[32], r[33], r[34], r[35], r[36], r[37], r[38], r[39]);
460     DNBLogThreaded("  s40=%8.8x s41=%8.8x s42=%8.8x s43=%8.8x s44=%8.8x "
461                    "s45=%8.8x s46=%8.8x s47=%8.8x",
462                    r[40], r[41], r[42], r[43], r[44], r[45], r[46], r[47]);
463     DNBLogThreaded("  s48=%8.8x s49=%8.8x s50=%8.8x s51=%8.8x s52=%8.8x "
464                    "s53=%8.8x s54=%8.8x s55=%8.8x",
465                    r[48], r[49], r[50], r[51], r[52], r[53], r[54], r[55]);
466     DNBLogThreaded("  s56=%8.8x s57=%8.8x s58=%8.8x s59=%8.8x s60=%8.8x "
467                    "s61=%8.8x s62=%8.8x s63=%8.8x fpscr=%8.8x",
468                    r[56], r[57], r[58], r[59], r[60], r[61], r[62], r[63],
469                    r[64]);
470   }
471 #endif
472 
473   m_state.SetError(set, Write,
474                    kret); // Set the current write error for this register set
475   m_state.InvalidateRegisterSetState(set); // Invalidate the current register
476                                            // state in case registers are read
477                                            // back differently
478   return kret;                             // Return the error code
479 }
480 
481 kern_return_t DNBArchMachARM::SetEXCState() {
482   int set = e_regSetEXC;
483   kern_return_t kret = ::thread_set_state(
484       m_thread->MachPortNumber(), ARM_EXCEPTION_STATE,
485       (thread_state_t)&m_state.context.exc, ARM_EXCEPTION_STATE_COUNT);
486   m_state.SetError(set, Write,
487                    kret); // Set the current write error for this register set
488   m_state.InvalidateRegisterSetState(set); // Invalidate the current register
489                                            // state in case registers are read
490                                            // back differently
491   return kret;                             // Return the error code
492 }
493 
494 kern_return_t DNBArchMachARM::SetDBGState(bool also_set_on_task) {
495   int set = e_regSetDBG;
496 #if defined(ARM_DEBUG_STATE32) && (defined(__arm64__) || defined(__aarch64__))
497   kern_return_t kret =
498       ::thread_set_state(m_thread->MachPortNumber(), ARM_DEBUG_STATE32,
499                          (thread_state_t)&m_state.dbg, ARM_DEBUG_STATE32_COUNT);
500   if (also_set_on_task) {
501     kern_return_t task_kret = ::task_set_state(
502         m_thread->Process()->Task().TaskPort(), ARM_DEBUG_STATE32,
503         (thread_state_t)&m_state.dbg, ARM_DEBUG_STATE32_COUNT);
504     if (task_kret != KERN_SUCCESS)
505       DNBLogThreadedIf(LOG_WATCHPOINTS, "DNBArchMachARM::SetDBGState failed to "
506                                         "set debug control register state: "
507                                         "0x%8.8x.",
508                        kret);
509   }
510 #else
511   kern_return_t kret =
512       ::thread_set_state(m_thread->MachPortNumber(), ARM_DEBUG_STATE,
513                          (thread_state_t)&m_state.dbg, ARM_DEBUG_STATE_COUNT);
514   if (also_set_on_task) {
515     kern_return_t task_kret = ::task_set_state(
516         m_thread->Process()->Task().TaskPort(), ARM_DEBUG_STATE,
517         (thread_state_t)&m_state.dbg, ARM_DEBUG_STATE_COUNT);
518     if (task_kret != KERN_SUCCESS)
519       DNBLogThreadedIf(LOG_WATCHPOINTS, "DNBArchMachARM::SetDBGState failed to "
520                                         "set debug control register state: "
521                                         "0x%8.8x.",
522                        kret);
523   }
524 #endif
525 
526   m_state.SetError(set, Write,
527                    kret); // Set the current write error for this register set
528   m_state.InvalidateRegisterSetState(set); // Invalidate the current register
529                                            // state in case registers are read
530                                            // back differently
531   return kret;                             // Return the error code
532 }
533 
534 void DNBArchMachARM::ThreadWillResume() {
535   // Do we need to step this thread? If so, let the mach thread tell us so.
536   if (m_thread->IsStepping()) {
537     // This is the primary thread, let the arch do anything it needs
538     if (NumSupportedHardwareBreakpoints() > 0) {
539       if (EnableHardwareSingleStep(true) != KERN_SUCCESS) {
540         DNBLogThreaded("DNBArchMachARM::ThreadWillResume() failed to enable "
541                        "hardware single step");
542       }
543     }
544   }
545 
546   // Disable the triggered watchpoint temporarily before we resume.
547   // Plus, we try to enable hardware single step to execute past the instruction
548   // which triggered our watchpoint.
549   if (m_watchpoint_did_occur) {
550     if (m_watchpoint_hw_index >= 0) {
551       kern_return_t kret = GetDBGState(false);
552       if (kret == KERN_SUCCESS &&
553           !IsWatchpointEnabled(m_state.dbg, m_watchpoint_hw_index)) {
554         // The watchpoint might have been disabled by the user.  We don't need
555         // to do anything at all
556         // to enable hardware single stepping.
557         m_watchpoint_did_occur = false;
558         m_watchpoint_hw_index = -1;
559         return;
560       }
561 
562       DisableHardwareWatchpoint(m_watchpoint_hw_index, false);
563       DNBLogThreadedIf(LOG_WATCHPOINTS, "DNBArchMachARM::ThreadWillResume() "
564                                         "DisableHardwareWatchpoint(%d) called",
565                        m_watchpoint_hw_index);
566 
567       // Enable hardware single step to move past the watchpoint-triggering
568       // instruction.
569       m_watchpoint_resume_single_step_enabled =
570           (EnableHardwareSingleStep(true) == KERN_SUCCESS);
571 
572       // If we are not able to enable single step to move past the
573       // watchpoint-triggering instruction,
574       // at least we should reset the two watchpoint member variables so that
575       // the next time around
576       // this callback function is invoked, the enclosing logical branch is
577       // skipped.
578       if (!m_watchpoint_resume_single_step_enabled) {
579         // Reset the two watchpoint member variables.
580         m_watchpoint_did_occur = false;
581         m_watchpoint_hw_index = -1;
582         DNBLogThreadedIf(
583             LOG_WATCHPOINTS,
584             "DNBArchMachARM::ThreadWillResume() failed to enable single step");
585       } else
586         DNBLogThreadedIf(LOG_WATCHPOINTS, "DNBArchMachARM::ThreadWillResume() "
587                                           "succeeded to enable single step");
588     }
589   }
590 }
591 
592 bool DNBArchMachARM::ThreadDidStop() {
593   bool success = true;
594 
595   m_state.InvalidateRegisterSetState(e_regSetALL);
596 
597   if (m_watchpoint_resume_single_step_enabled) {
598     // Great!  We now disable the hardware single step as well as re-enable the
599     // hardware watchpoint.
600     // See also ThreadWillResume().
601     if (EnableHardwareSingleStep(false) == KERN_SUCCESS) {
602       if (m_watchpoint_did_occur && m_watchpoint_hw_index >= 0) {
603         ReenableHardwareWatchpoint(m_watchpoint_hw_index);
604         m_watchpoint_resume_single_step_enabled = false;
605         m_watchpoint_did_occur = false;
606         m_watchpoint_hw_index = -1;
607       } else {
608         DNBLogError("internal error detected: m_watchpoint_resume_step_enabled "
609                     "is true but (m_watchpoint_did_occur && "
610                     "m_watchpoint_hw_index >= 0) does not hold!");
611       }
612     } else {
613       DNBLogError("internal error detected: m_watchpoint_resume_step_enabled "
614                   "is true but unable to disable single step!");
615     }
616   }
617 
618   // Are we stepping a single instruction?
619   if (GetGPRState(true) == KERN_SUCCESS) {
620     // We are single stepping, was this the primary thread?
621     if (m_thread->IsStepping()) {
622       success = EnableHardwareSingleStep(false) == KERN_SUCCESS;
623     } else {
624       // The MachThread will automatically restore the suspend count
625       // in ThreadDidStop(), so we don't need to do anything here if
626       // we weren't the primary thread the last time
627     }
628   }
629   return success;
630 }
631 
632 bool DNBArchMachARM::NotifyException(MachException::Data &exc) {
633   switch (exc.exc_type) {
634   default:
635     break;
636   case EXC_BREAKPOINT:
637     if (exc.exc_data.size() == 2 && exc.exc_data[0] == EXC_ARM_DA_DEBUG) {
638       // The data break address is passed as exc_data[1].
639       nub_addr_t addr = exc.exc_data[1];
640       // Find the hardware index with the side effect of possibly massaging the
641       // addr to return the starting address as seen from the debugger side.
642       uint32_t hw_index = GetHardwareWatchpointHit(addr);
643       DNBLogThreadedIf(LOG_WATCHPOINTS, "DNBArchMachARM::NotifyException "
644                                         "watchpoint %d was hit on address "
645                                         "0x%llx",
646                        hw_index, (uint64_t)addr);
647       const int num_watchpoints = NumSupportedHardwareWatchpoints();
648       for (int i = 0; i < num_watchpoints; i++) {
649         if (LoHi[i] != 0 && LoHi[i] == hw_index && LoHi[i] != i &&
650             GetWatchpointAddressByIndex(i) != INVALID_NUB_ADDRESS) {
651           addr = GetWatchpointAddressByIndex(i);
652           DNBLogThreadedIf(LOG_WATCHPOINTS, "DNBArchMachARM::NotifyException "
653                                             "It is a linked watchpoint; "
654                                             "rewritten to index %d addr 0x%llx",
655                            LoHi[i], (uint64_t)addr);
656         }
657       }
658       if (hw_index != INVALID_NUB_HW_INDEX) {
659         m_watchpoint_did_occur = true;
660         m_watchpoint_hw_index = hw_index;
661         exc.exc_data[1] = addr;
662         // Piggyback the hw_index in the exc.data.
663         exc.exc_data.push_back(hw_index);
664       }
665 
666       return true;
667     }
668     break;
669   }
670   return false;
671 }
672 
673 bool DNBArchMachARM::StepNotComplete() {
674   if (m_hw_single_chained_step_addr != INVALID_NUB_ADDRESS) {
675     kern_return_t kret = KERN_INVALID_ARGUMENT;
676     kret = GetGPRState(false);
677     if (kret == KERN_SUCCESS) {
678       if (m_state.context.gpr.__pc == m_hw_single_chained_step_addr) {
679         DNBLogThreadedIf(LOG_STEP, "Need to step some more at 0x%8.8llx",
680                          (uint64_t)m_hw_single_chained_step_addr);
681         return true;
682       }
683     }
684   }
685 
686   m_hw_single_chained_step_addr = INVALID_NUB_ADDRESS;
687   return false;
688 }
689 
690 // Set the single step bit in the processor status register.
691 kern_return_t DNBArchMachARM::EnableHardwareSingleStep(bool enable) {
692   DNBError err;
693   DNBLogThreadedIf(LOG_STEP, "%s( enable = %d )", __FUNCTION__, enable);
694 
695   err = GetGPRState(false);
696 
697   if (err.Fail()) {
698     err.LogThreaded("%s: failed to read the GPR registers", __FUNCTION__);
699     return err.Error();
700   }
701 
702   err = GetDBGState(false);
703 
704   if (err.Fail()) {
705     err.LogThreaded("%s: failed to read the DBG registers", __FUNCTION__);
706     return err.Error();
707   }
708 
709 // The use of __arm64__ here is not ideal.  If debugserver is running on
710 // an armv8 device, regardless of whether it was built for arch arm or arch
711 // arm64,
712 // it needs to use the MDSCR_EL1 SS bit to single instruction step.
713 
714 #if defined(__arm64__) || defined(__aarch64__)
715   if (enable) {
716     DNBLogThreadedIf(LOG_STEP,
717                      "%s: Setting MDSCR_EL1 Single Step bit at pc 0x%llx",
718                      __FUNCTION__, (uint64_t)m_state.context.gpr.__pc);
719     m_state.dbg.__mdscr_el1 |=
720         1; // Set bit 0 (single step, SS) in the MDSCR_EL1.
721   } else {
722     DNBLogThreadedIf(LOG_STEP,
723                      "%s: Clearing MDSCR_EL1 Single Step bit at pc 0x%llx",
724                      __FUNCTION__, (uint64_t)m_state.context.gpr.__pc);
725     m_state.dbg.__mdscr_el1 &=
726         ~(1ULL); // Clear bit 0 (single step, SS) in the MDSCR_EL1.
727   }
728 #else
729   const uint32_t i = 0;
730   if (enable) {
731     m_hw_single_chained_step_addr = INVALID_NUB_ADDRESS;
732 
733     // Save our previous state
734     m_dbg_save = m_state.dbg;
735     // Set a breakpoint that will stop when the PC doesn't match the current
736     // one!
737     m_state.dbg.__bvr[i] =
738         m_state.context.gpr.__pc &
739         0xFFFFFFFCu; // Set the current PC as the breakpoint address
740     m_state.dbg.__bcr[i] = BCR_M_IMVA_MISMATCH | // Stop on address mismatch
741                            S_USER |              // Stop only in user mode
742                            BCR_ENABLE;           // Enable this breakpoint
743     if (m_state.context.gpr.__cpsr & 0x20) {
744       // Thumb breakpoint
745       if (m_state.context.gpr.__pc & 2)
746         m_state.dbg.__bcr[i] |= BAS_IMVA_2_3;
747       else
748         m_state.dbg.__bcr[i] |= BAS_IMVA_0_1;
749 
750       uint16_t opcode;
751       if (sizeof(opcode) ==
752           m_thread->Process()->Task().ReadMemory(m_state.context.gpr.__pc,
753                                                  sizeof(opcode), &opcode)) {
754         if (IsThumb32Opcode(opcode)) {
755           // 32 bit thumb opcode...
756           if (m_state.context.gpr.__pc & 2) {
757             // We can't take care of a 32 bit thumb instruction single step
758             // with just IVA mismatching. We will need to chain an extra
759             // hardware single step in order to complete this single step...
760             m_hw_single_chained_step_addr = m_state.context.gpr.__pc + 2;
761           } else {
762             // Extend the number of bits to ignore for the mismatch
763             m_state.dbg.__bcr[i] |= BAS_IMVA_ALL;
764           }
765         }
766       }
767     } else {
768       // ARM breakpoint
769       m_state.dbg.__bcr[i] |= BAS_IMVA_ALL; // Stop when any address bits change
770     }
771 
772     DNBLogThreadedIf(LOG_STEP, "%s: BVR%u=0x%8.8x  BCR%u=0x%8.8x", __FUNCTION__,
773                      i, m_state.dbg.__bvr[i], i, m_state.dbg.__bcr[i]);
774 
775     for (uint32_t j = i + 1; j < 16; ++j) {
776       // Disable all others
777       m_state.dbg.__bvr[j] = 0;
778       m_state.dbg.__bcr[j] = 0;
779     }
780   } else {
781     // Just restore the state we had before we did single stepping
782     m_state.dbg = m_dbg_save;
783   }
784 #endif
785 
786   return SetDBGState(false);
787 }
788 
789 // return 1 if bit "BIT" is set in "value"
790 static inline uint32_t bit(uint32_t value, uint32_t bit) {
791   return (value >> bit) & 1u;
792 }
793 
794 // return the bitfield "value[msbit:lsbit]".
795 static inline uint32_t bits(uint32_t value, uint32_t msbit, uint32_t lsbit) {
796   assert(msbit >= lsbit);
797   uint32_t shift_left = sizeof(value) * 8 - 1 - msbit;
798   value <<=
799       shift_left; // shift anything above the msbit off of the unsigned edge
800   value >>= (shift_left + lsbit); // shift it back again down to the lsbit
801                                   // (including undoing any shift from above)
802   return value;                   // return our result
803 }
804 
805 bool DNBArchMachARM::ConditionPassed(uint8_t condition, uint32_t cpsr) {
806   uint32_t cpsr_n = bit(cpsr, 31); // Negative condition code flag
807   uint32_t cpsr_z = bit(cpsr, 30); // Zero condition code flag
808   uint32_t cpsr_c = bit(cpsr, 29); // Carry condition code flag
809   uint32_t cpsr_v = bit(cpsr, 28); // Overflow condition code flag
810 
811   switch (condition) {
812   case COND_EQ: // (0x0)
813     if (cpsr_z == 1)
814       return true;
815     break;
816   case COND_NE: // (0x1)
817     if (cpsr_z == 0)
818       return true;
819     break;
820   case COND_CS: // (0x2)
821     if (cpsr_c == 1)
822       return true;
823     break;
824   case COND_CC: // (0x3)
825     if (cpsr_c == 0)
826       return true;
827     break;
828   case COND_MI: // (0x4)
829     if (cpsr_n == 1)
830       return true;
831     break;
832   case COND_PL: // (0x5)
833     if (cpsr_n == 0)
834       return true;
835     break;
836   case COND_VS: // (0x6)
837     if (cpsr_v == 1)
838       return true;
839     break;
840   case COND_VC: // (0x7)
841     if (cpsr_v == 0)
842       return true;
843     break;
844   case COND_HI: // (0x8)
845     if ((cpsr_c == 1) && (cpsr_z == 0))
846       return true;
847     break;
848   case COND_LS: // (0x9)
849     if ((cpsr_c == 0) || (cpsr_z == 1))
850       return true;
851     break;
852   case COND_GE: // (0xA)
853     if (cpsr_n == cpsr_v)
854       return true;
855     break;
856   case COND_LT: // (0xB)
857     if (cpsr_n != cpsr_v)
858       return true;
859     break;
860   case COND_GT: // (0xC)
861     if ((cpsr_z == 0) && (cpsr_n == cpsr_v))
862       return true;
863     break;
864   case COND_LE: // (0xD)
865     if ((cpsr_z == 1) || (cpsr_n != cpsr_v))
866       return true;
867     break;
868   default:
869     return true;
870     break;
871   }
872 
873   return false;
874 }
875 
876 uint32_t DNBArchMachARM::NumSupportedHardwareBreakpoints() {
877   // Set the init value to something that will let us know that we need to
878   // autodetect how many breakpoints are supported dynamically...
879   static uint32_t g_num_supported_hw_breakpoints = UINT_MAX;
880   if (g_num_supported_hw_breakpoints == UINT_MAX) {
881     // Set this to zero in case we can't tell if there are any HW breakpoints
882     g_num_supported_hw_breakpoints = 0;
883 
884     size_t len;
885     uint32_t n = 0;
886     len = sizeof(n);
887     if (::sysctlbyname("hw.optional.breakpoint", &n, &len, NULL, 0) == 0) {
888       g_num_supported_hw_breakpoints = n;
889       DNBLogThreadedIf(LOG_THREAD, "hw.optional.breakpoint=%u", n);
890     } else {
891 #if !defined(__arm64__) && !defined(__aarch64__)
892       // Read the DBGDIDR to get the number of available hardware breakpoints
893       // However, in some of our current armv7 processors, hardware
894       // breakpoints/watchpoints were not properly connected. So detect those
895       // cases using a field in a sysctl. For now we are using "hw.cpusubtype"
896       // field to distinguish CPU architectures. This is a hack until we can
897       // get <rdar://problem/6372672> fixed, at which point we will switch to
898       // using a different sysctl string that will tell us how many BRPs
899       // are available to us directly without having to read DBGDIDR.
900       uint32_t register_DBGDIDR;
901 
902       asm("mrc p14, 0, %0, c0, c0, 0" : "=r"(register_DBGDIDR));
903       uint32_t numBRPs = bits(register_DBGDIDR, 27, 24);
904       // Zero is reserved for the BRP count, so don't increment it if it is zero
905       if (numBRPs > 0)
906         numBRPs++;
907       DNBLogThreadedIf(LOG_THREAD, "DBGDIDR=0x%8.8x (number BRP pairs = %u)",
908                        register_DBGDIDR, numBRPs);
909 
910       if (numBRPs > 0) {
911         uint32_t cpusubtype;
912         len = sizeof(cpusubtype);
913         // TODO: remove this hack and change to using hw.optional.xx when
914         // implmented
915         if (::sysctlbyname("hw.cpusubtype", &cpusubtype, &len, NULL, 0) == 0) {
916           DNBLogThreadedIf(LOG_THREAD, "hw.cpusubtype=%d", cpusubtype);
917           if (cpusubtype == CPU_SUBTYPE_ARM_V7)
918             DNBLogThreadedIf(LOG_THREAD, "Hardware breakpoints disabled for "
919                                          "armv7 (rdar://problem/6372672)");
920           else
921             g_num_supported_hw_breakpoints = numBRPs;
922         }
923       }
924 #endif
925     }
926   }
927   return g_num_supported_hw_breakpoints;
928 }
929 
930 uint32_t DNBArchMachARM::NumSupportedHardwareWatchpoints() {
931   // Set the init value to something that will let us know that we need to
932   // autodetect how many watchpoints are supported dynamically...
933   static uint32_t g_num_supported_hw_watchpoints = UINT_MAX;
934   if (g_num_supported_hw_watchpoints == UINT_MAX) {
935     // Set this to zero in case we can't tell if there are any HW breakpoints
936     g_num_supported_hw_watchpoints = 0;
937 
938     size_t len;
939     uint32_t n = 0;
940     len = sizeof(n);
941     if (::sysctlbyname("hw.optional.watchpoint", &n, &len, NULL, 0) == 0) {
942       g_num_supported_hw_watchpoints = n;
943       DNBLogThreadedIf(LOG_THREAD, "hw.optional.watchpoint=%u", n);
944     } else {
945 #if !defined(__arm64__) && !defined(__aarch64__)
946       // Read the DBGDIDR to get the number of available hardware breakpoints
947       // However, in some of our current armv7 processors, hardware
948       // breakpoints/watchpoints were not properly connected. So detect those
949       // cases using a field in a sysctl. For now we are using "hw.cpusubtype"
950       // field to distinguish CPU architectures. This is a hack until we can
951       // get <rdar://problem/6372672> fixed, at which point we will switch to
952       // using a different sysctl string that will tell us how many WRPs
953       // are available to us directly without having to read DBGDIDR.
954 
955       uint32_t register_DBGDIDR;
956       asm("mrc p14, 0, %0, c0, c0, 0" : "=r"(register_DBGDIDR));
957       uint32_t numWRPs = bits(register_DBGDIDR, 31, 28) + 1;
958       DNBLogThreadedIf(LOG_THREAD, "DBGDIDR=0x%8.8x (number WRP pairs = %u)",
959                        register_DBGDIDR, numWRPs);
960 
961       if (numWRPs > 0) {
962         uint32_t cpusubtype;
963         size_t len;
964         len = sizeof(cpusubtype);
965         // TODO: remove this hack and change to using hw.optional.xx when
966         // implmented
967         if (::sysctlbyname("hw.cpusubtype", &cpusubtype, &len, NULL, 0) == 0) {
968           DNBLogThreadedIf(LOG_THREAD, "hw.cpusubtype=0x%d", cpusubtype);
969 
970           if (cpusubtype == CPU_SUBTYPE_ARM_V7)
971             DNBLogThreadedIf(LOG_THREAD, "Hardware watchpoints disabled for "
972                                          "armv7 (rdar://problem/6372672)");
973           else
974             g_num_supported_hw_watchpoints = numWRPs;
975         }
976       }
977 #endif
978     }
979   }
980   return g_num_supported_hw_watchpoints;
981 }
982 
983 uint32_t DNBArchMachARM::EnableHardwareBreakpoint(nub_addr_t addr,
984                                                   nub_size_t size) {
985   // Make sure our address isn't bogus
986   if (addr & 1)
987     return INVALID_NUB_HW_INDEX;
988 
989   kern_return_t kret = GetDBGState(false);
990 
991   if (kret == KERN_SUCCESS) {
992     const uint32_t num_hw_breakpoints = NumSupportedHardwareBreakpoints();
993     uint32_t i;
994     for (i = 0; i < num_hw_breakpoints; ++i) {
995       if ((m_state.dbg.__bcr[i] & BCR_ENABLE) == 0)
996         break; // We found an available hw breakpoint slot (in i)
997     }
998 
999     // See if we found an available hw breakpoint slot above
1000     if (i < num_hw_breakpoints) {
1001       // Make sure bits 1:0 are clear in our address
1002       m_state.dbg.__bvr[i] = addr & ~((nub_addr_t)3);
1003 
1004       if (size == 2 || addr & 2) {
1005         uint32_t byte_addr_select = (addr & 2) ? BAS_IMVA_2_3 : BAS_IMVA_0_1;
1006 
1007         // We have a thumb breakpoint
1008         // We have an ARM breakpoint
1009         m_state.dbg.__bcr[i] =
1010             BCR_M_IMVA_MATCH | // Stop on address mismatch
1011             byte_addr_select | // Set the correct byte address select so we only
1012                                // trigger on the correct opcode
1013             S_USER |           // Which modes should this breakpoint stop in?
1014             BCR_ENABLE;        // Enable this hardware breakpoint
1015         DNBLogThreadedIf(LOG_BREAKPOINTS,
1016                          "DNBArchMachARM::EnableHardwareBreakpoint( addr = "
1017                          "0x%8.8llx, size = %llu ) - BVR%u/BCR%u = 0x%8.8x / "
1018                          "0x%8.8x (Thumb)",
1019                          (uint64_t)addr, (uint64_t)size, i, i,
1020                          m_state.dbg.__bvr[i], m_state.dbg.__bcr[i]);
1021       } else if (size == 4) {
1022         // We have an ARM breakpoint
1023         m_state.dbg.__bcr[i] =
1024             BCR_M_IMVA_MATCH | // Stop on address mismatch
1025             BAS_IMVA_ALL | // Stop on any of the four bytes following the IMVA
1026             S_USER |       // Which modes should this breakpoint stop in?
1027             BCR_ENABLE;    // Enable this hardware breakpoint
1028         DNBLogThreadedIf(LOG_BREAKPOINTS,
1029                          "DNBArchMachARM::EnableHardwareBreakpoint( addr = "
1030                          "0x%8.8llx, size = %llu ) - BVR%u/BCR%u = 0x%8.8x / "
1031                          "0x%8.8x (ARM)",
1032                          (uint64_t)addr, (uint64_t)size, i, i,
1033                          m_state.dbg.__bvr[i], m_state.dbg.__bcr[i]);
1034       }
1035 
1036       kret = SetDBGState(false);
1037       DNBLogThreadedIf(LOG_BREAKPOINTS, "DNBArchMachARM::"
1038                                         "EnableHardwareBreakpoint() "
1039                                         "SetDBGState() => 0x%8.8x.",
1040                        kret);
1041 
1042       if (kret == KERN_SUCCESS)
1043         return i;
1044     } else {
1045       DNBLogThreadedIf(LOG_BREAKPOINTS,
1046                        "DNBArchMachARM::EnableHardwareBreakpoint(addr = "
1047                        "0x%8.8llx, size = %llu) => all hardware breakpoint "
1048                        "resources are being used.",
1049                        (uint64_t)addr, (uint64_t)size);
1050     }
1051   }
1052 
1053   return INVALID_NUB_HW_INDEX;
1054 }
1055 
1056 bool DNBArchMachARM::DisableHardwareBreakpoint(uint32_t hw_index) {
1057   kern_return_t kret = GetDBGState(false);
1058 
1059   const uint32_t num_hw_points = NumSupportedHardwareBreakpoints();
1060   if (kret == KERN_SUCCESS) {
1061     if (hw_index < num_hw_points) {
1062       m_state.dbg.__bcr[hw_index] = 0;
1063       DNBLogThreadedIf(LOG_BREAKPOINTS, "DNBArchMachARM::SetHardwareBreakpoint("
1064                                         " %u ) - BVR%u = 0x%8.8x  BCR%u = "
1065                                         "0x%8.8x",
1066                        hw_index, hw_index, m_state.dbg.__bvr[hw_index],
1067                        hw_index, m_state.dbg.__bcr[hw_index]);
1068 
1069       kret = SetDBGState(false);
1070 
1071       if (kret == KERN_SUCCESS)
1072         return true;
1073     }
1074   }
1075   return false;
1076 }
1077 
1078 // ARM v7 watchpoints may be either word-size or double-word-size.
1079 // It's implementation defined which they can handle.  It looks like on an
1080 // armv8 device, armv7 processes can watch dwords.  But on a genuine armv7
1081 // device I tried, only word watchpoints are supported.
1082 
1083 #if defined(__arm64__) || defined(__aarch64__)
1084 #define WATCHPOINTS_ARE_DWORD 1
1085 #else
1086 #undef WATCHPOINTS_ARE_DWORD
1087 #endif
1088 
1089 uint32_t DNBArchMachARM::EnableHardwareWatchpoint(nub_addr_t addr,
1090                                                   nub_size_t size, bool read,
1091                                                   bool write,
1092                                                   bool also_set_on_task) {
1093 
1094   DNBLogThreadedIf(LOG_WATCHPOINTS, "DNBArchMachARM::EnableHardwareWatchpoint("
1095                                     "addr = 0x%8.8llx, size = %zu, read = %u, "
1096                                     "write = %u)",
1097                    (uint64_t)addr, size, read, write);
1098 
1099   const uint32_t num_hw_watchpoints = NumSupportedHardwareWatchpoints();
1100 
1101   // Can't watch zero bytes
1102   if (size == 0)
1103     return INVALID_NUB_HW_INDEX;
1104 
1105   // We must watch for either read or write
1106   if (read == false && write == false)
1107     return INVALID_NUB_HW_INDEX;
1108 
1109   // Otherwise, can't watch more than 8 bytes per WVR/WCR pair
1110   if (size > 8)
1111     return INVALID_NUB_HW_INDEX;
1112 
1113 // Treat arm watchpoints as having an 8-byte alignment requirement.  You can put
1114 // a watchpoint on a 4-byte
1115 // offset address but you can only watch 4 bytes with that watchpoint.
1116 
1117 // arm watchpoints on an 8-byte (double word) aligned addr can watch any bytes
1118 // in that
1119 // 8-byte long region of memory.  They can watch the 1st byte, the 2nd byte, 3rd
1120 // byte, etc, or any
1121 // combination therein by setting the bits in the BAS [12:5] (Byte Address
1122 // Select) field of
1123 // the DBGWCRn_EL1 reg for the watchpoint.
1124 
1125 // If the MASK [28:24] bits in the DBGWCRn_EL1 allow a single watchpoint to
1126 // monitor a larger region
1127 // of memory (16 bytes, 32 bytes, or 2GB) but the Byte Address Select bitfield
1128 // then selects a larger
1129 // range of bytes, instead of individual bytes.  See the ARMv8 Debug
1130 // Architecture manual for details.
1131 // This implementation does not currently use the MASK bits; the largest single
1132 // region watched by a single
1133 // watchpoint right now is 8-bytes.
1134 
1135 #if defined(WATCHPOINTS_ARE_DWORD)
1136   nub_addr_t aligned_wp_address = addr & ~0x7;
1137   uint32_t addr_dword_offset = addr & 0x7;
1138   const int max_watchpoint_size = 8;
1139 #else
1140   nub_addr_t aligned_wp_address = addr & ~0x3;
1141   uint32_t addr_dword_offset = addr & 0x3;
1142   const int max_watchpoint_size = 4;
1143 #endif
1144 
1145   DNBLogThreadedIf(LOG_WATCHPOINTS, "DNBArchMachARM::EnableHardwareWatchpoint "
1146                                     "aligned_wp_address is 0x%llx and "
1147                                     "addr_dword_offset is 0x%x",
1148                    (uint64_t)aligned_wp_address, addr_dword_offset);
1149 
1150   // Do we need to split up this logical watchpoint into two hardware watchpoint
1151   // registers?
1152   // e.g. a watchpoint of length 4 on address 6.  We need do this with
1153   //   one watchpoint on address 0 with bytes 6 & 7 being monitored
1154   //   one watchpoint on address 8 with bytes 0, 1, 2, 3 being monitored
1155 
1156   if (addr_dword_offset + size > max_watchpoint_size) {
1157     DNBLogThreadedIf(LOG_WATCHPOINTS, "DNBArchMachARM::"
1158                                       "EnableHardwareWatchpoint(addr = "
1159                                       "0x%8.8llx, size = %zu) needs two "
1160                                       "hardware watchpoints slots to monitor",
1161                      (uint64_t)addr, size);
1162     int low_watchpoint_size = max_watchpoint_size - addr_dword_offset;
1163     int high_watchpoint_size = addr_dword_offset + size - max_watchpoint_size;
1164 
1165     uint32_t lo = EnableHardwareWatchpoint(addr, low_watchpoint_size, read,
1166                                            write, also_set_on_task);
1167     if (lo == INVALID_NUB_HW_INDEX)
1168       return INVALID_NUB_HW_INDEX;
1169     uint32_t hi = EnableHardwareWatchpoint(
1170         aligned_wp_address + max_watchpoint_size, high_watchpoint_size, read,
1171         write, also_set_on_task);
1172     if (hi == INVALID_NUB_HW_INDEX) {
1173       DisableHardwareWatchpoint(lo, also_set_on_task);
1174       return INVALID_NUB_HW_INDEX;
1175     }
1176     // Tag this lo->hi mapping in our database.
1177     LoHi[lo] = hi;
1178     return lo;
1179   }
1180 
1181   // At this point
1182   //  1 aligned_wp_address is the requested address rounded down to 8-byte
1183   //  alignment
1184   //  2 addr_dword_offset is the offset into that double word (8-byte) region
1185   //  that we are watching
1186   //  3 size is the number of bytes within that 8-byte region that we are
1187   //  watching
1188 
1189   // Set the Byte Address Selects bits DBGWCRn_EL1 bits [12:5] based on the
1190   // above.
1191   // The bit shift and negation operation will give us 0b11 for 2, 0b1111 for 4,
1192   // etc, up to 0b11111111 for 8.
1193   // then we shift those bits left by the offset into this dword that we are
1194   // interested in.
1195   // e.g. if we are watching bytes 4,5,6,7 in a dword we want a BAS of
1196   // 0b11110000.
1197   uint32_t byte_address_select = ((1 << size) - 1) << addr_dword_offset;
1198 
1199   // Read the debug state
1200   kern_return_t kret = GetDBGState(true);
1201 
1202   if (kret == KERN_SUCCESS) {
1203     // Check to make sure we have the needed hardware support
1204     uint32_t i = 0;
1205 
1206     for (i = 0; i < num_hw_watchpoints; ++i) {
1207       if ((m_state.dbg.__wcr[i] & WCR_ENABLE) == 0)
1208         break; // We found an available hw watchpoint slot (in i)
1209     }
1210 
1211     // See if we found an available hw watchpoint slot above
1212     if (i < num_hw_watchpoints) {
1213       // DumpDBGState(m_state.dbg);
1214 
1215       // Clear any previous LoHi joined-watchpoint that may have been in use
1216       LoHi[i] = 0;
1217 
1218       // shift our Byte Address Select bits up to the correct bit range for the
1219       // DBGWCRn_EL1
1220       byte_address_select = byte_address_select << 5;
1221 
1222       // Make sure bits 1:0 are clear in our address
1223       m_state.dbg.__wvr[i] = aligned_wp_address;   // DVA (Data Virtual Address)
1224       m_state.dbg.__wcr[i] = byte_address_select | // Which bytes that follow
1225                                                    // the DVA that we will watch
1226                              S_USER |              // Stop only in user mode
1227                              (read ? WCR_LOAD : 0) |   // Stop on read access?
1228                              (write ? WCR_STORE : 0) | // Stop on write access?
1229                              WCR_ENABLE; // Enable this watchpoint;
1230 
1231       DNBLogThreadedIf(
1232           LOG_WATCHPOINTS, "DNBArchMachARM::EnableHardwareWatchpoint() adding "
1233                            "watchpoint on address 0x%llx with control register "
1234                            "value 0x%x",
1235           (uint64_t)m_state.dbg.__wvr[i], (uint32_t)m_state.dbg.__wcr[i]);
1236 
1237       // The kernel will set the MDE_ENABLE bit in the MDSCR_EL1 for us
1238       // automatically, don't need to do it here.
1239 
1240       kret = SetDBGState(also_set_on_task);
1241       // DumpDBGState(m_state.dbg);
1242 
1243       DNBLogThreadedIf(LOG_WATCHPOINTS, "DNBArchMachARM::"
1244                                         "EnableHardwareWatchpoint() "
1245                                         "SetDBGState() => 0x%8.8x.",
1246                        kret);
1247 
1248       if (kret == KERN_SUCCESS)
1249         return i;
1250     } else {
1251       DNBLogThreadedIf(LOG_WATCHPOINTS, "DNBArchMachARM::"
1252                                         "EnableHardwareWatchpoint(): All "
1253                                         "hardware resources (%u) are in use.",
1254                        num_hw_watchpoints);
1255     }
1256   }
1257   return INVALID_NUB_HW_INDEX;
1258 }
1259 
1260 bool DNBArchMachARM::ReenableHardwareWatchpoint(uint32_t hw_index) {
1261   // If this logical watchpoint # is actually implemented using
1262   // two hardware watchpoint registers, re-enable both of them.
1263 
1264   if (hw_index < NumSupportedHardwareWatchpoints() && LoHi[hw_index]) {
1265     return ReenableHardwareWatchpoint_helper(hw_index) &&
1266            ReenableHardwareWatchpoint_helper(LoHi[hw_index]);
1267   } else {
1268     return ReenableHardwareWatchpoint_helper(hw_index);
1269   }
1270 }
1271 
1272 bool DNBArchMachARM::ReenableHardwareWatchpoint_helper(uint32_t hw_index) {
1273   kern_return_t kret = GetDBGState(false);
1274   if (kret != KERN_SUCCESS)
1275     return false;
1276   const uint32_t num_hw_points = NumSupportedHardwareWatchpoints();
1277   if (hw_index >= num_hw_points)
1278     return false;
1279 
1280   m_state.dbg.__wvr[hw_index] = m_disabled_watchpoints[hw_index].addr;
1281   m_state.dbg.__wcr[hw_index] = m_disabled_watchpoints[hw_index].control;
1282 
1283   DNBLogThreadedIf(LOG_WATCHPOINTS, "DNBArchMachARM::EnableHardwareWatchpoint( "
1284                                     "%u ) - WVR%u = 0x%8.8llx  WCR%u = "
1285                                     "0x%8.8llx",
1286                    hw_index, hw_index, (uint64_t)m_state.dbg.__wvr[hw_index],
1287                    hw_index, (uint64_t)m_state.dbg.__wcr[hw_index]);
1288 
1289   // The kernel will set the MDE_ENABLE bit in the MDSCR_EL1 for us
1290   // automatically, don't need to do it here.
1291 
1292   kret = SetDBGState(false);
1293 
1294   return (kret == KERN_SUCCESS);
1295 }
1296 
1297 bool DNBArchMachARM::DisableHardwareWatchpoint(uint32_t hw_index,
1298                                                bool also_set_on_task) {
1299   if (hw_index < NumSupportedHardwareWatchpoints() && LoHi[hw_index]) {
1300     return DisableHardwareWatchpoint_helper(hw_index, also_set_on_task) &&
1301            DisableHardwareWatchpoint_helper(LoHi[hw_index], also_set_on_task);
1302   } else {
1303     return DisableHardwareWatchpoint_helper(hw_index, also_set_on_task);
1304   }
1305 }
1306 
1307 bool DNBArchMachARM::DisableHardwareWatchpoint_helper(uint32_t hw_index,
1308                                                       bool also_set_on_task) {
1309   kern_return_t kret = GetDBGState(false);
1310   if (kret != KERN_SUCCESS)
1311     return false;
1312 
1313   const uint32_t num_hw_points = NumSupportedHardwareWatchpoints();
1314   if (hw_index >= num_hw_points)
1315     return false;
1316 
1317   m_disabled_watchpoints[hw_index].addr = m_state.dbg.__wvr[hw_index];
1318   m_disabled_watchpoints[hw_index].control = m_state.dbg.__wcr[hw_index];
1319 
1320   m_state.dbg.__wvr[hw_index] = 0;
1321   m_state.dbg.__wcr[hw_index] = 0;
1322   DNBLogThreadedIf(LOG_WATCHPOINTS, "DNBArchMachARM::DisableHardwareWatchpoint("
1323                                     " %u ) - WVR%u = 0x%8.8llx  WCR%u = "
1324                                     "0x%8.8llx",
1325                    hw_index, hw_index, (uint64_t)m_state.dbg.__wvr[hw_index],
1326                    hw_index, (uint64_t)m_state.dbg.__wcr[hw_index]);
1327 
1328   kret = SetDBGState(also_set_on_task);
1329 
1330   return (kret == KERN_SUCCESS);
1331 }
1332 
1333 // Returns -1 if the trailing bit patterns are not one of:
1334 // { 0b???1, 0b??10, 0b?100, 0b1000 }.
1335 static inline int32_t LowestBitSet(uint32_t val) {
1336   for (unsigned i = 0; i < 4; ++i) {
1337     if (bit(val, i))
1338       return i;
1339   }
1340   return -1;
1341 }
1342 
1343 // Iterate through the debug registers; return the index of the first watchpoint
1344 // whose address matches.
1345 // As a side effect, the starting address as understood by the debugger is
1346 // returned which could be
1347 // different from 'addr' passed as an in/out argument.
1348 uint32_t DNBArchMachARM::GetHardwareWatchpointHit(nub_addr_t &addr) {
1349   // Read the debug state
1350   kern_return_t kret = GetDBGState(true);
1351   // DumpDBGState(m_state.dbg);
1352   DNBLogThreadedIf(
1353       LOG_WATCHPOINTS,
1354       "DNBArchMachARM::GetHardwareWatchpointHit() GetDBGState() => 0x%8.8x.",
1355       kret);
1356   DNBLogThreadedIf(LOG_WATCHPOINTS,
1357                    "DNBArchMachARM::GetHardwareWatchpointHit() addr = 0x%llx",
1358                    (uint64_t)addr);
1359 
1360 // This is the watchpoint value to match against, i.e., word address.
1361 #if defined(WATCHPOINTS_ARE_DWORD)
1362   nub_addr_t wp_val = addr & ~((nub_addr_t)7);
1363 #else
1364   nub_addr_t wp_val = addr & ~((nub_addr_t)3);
1365 #endif
1366   if (kret == KERN_SUCCESS) {
1367     DBG &debug_state = m_state.dbg;
1368     uint32_t i, num = NumSupportedHardwareWatchpoints();
1369     for (i = 0; i < num; ++i) {
1370       nub_addr_t wp_addr = GetWatchAddress(debug_state, i);
1371       DNBLogThreadedIf(LOG_WATCHPOINTS, "DNBArchMachARM::"
1372                                         "GetHardwareWatchpointHit() slot: %u "
1373                                         "(addr = 0x%llx).",
1374                        i, (uint64_t)wp_addr);
1375       if (wp_val == wp_addr) {
1376 #if defined(WATCHPOINTS_ARE_DWORD)
1377         uint32_t byte_mask = bits(debug_state.__wcr[i], 12, 5);
1378 #else
1379         uint32_t byte_mask = bits(debug_state.__wcr[i], 8, 5);
1380 #endif
1381 
1382         // Sanity check the byte_mask, first.
1383         if (LowestBitSet(byte_mask) < 0)
1384           continue;
1385 
1386         // Compute the starting address (from the point of view of the
1387         // debugger).
1388         addr = wp_addr + LowestBitSet(byte_mask);
1389         return i;
1390       }
1391     }
1392   }
1393   return INVALID_NUB_HW_INDEX;
1394 }
1395 
1396 nub_addr_t DNBArchMachARM::GetWatchpointAddressByIndex(uint32_t hw_index) {
1397   kern_return_t kret = GetDBGState(true);
1398   if (kret != KERN_SUCCESS)
1399     return INVALID_NUB_ADDRESS;
1400   const uint32_t num = NumSupportedHardwareWatchpoints();
1401   if (hw_index >= num)
1402     return INVALID_NUB_ADDRESS;
1403   if (IsWatchpointEnabled(m_state.dbg, hw_index))
1404     return GetWatchAddress(m_state.dbg, hw_index);
1405   return INVALID_NUB_ADDRESS;
1406 }
1407 
1408 bool DNBArchMachARM::IsWatchpointEnabled(const DBG &debug_state,
1409                                          uint32_t hw_index) {
1410   // Watchpoint Control Registers, bitfield definitions
1411   // ...
1412   // Bits    Value    Description
1413   // [0]     0        Watchpoint disabled
1414   //         1        Watchpoint enabled.
1415   return (debug_state.__wcr[hw_index] & 1u);
1416 }
1417 
1418 nub_addr_t DNBArchMachARM::GetWatchAddress(const DBG &debug_state,
1419                                            uint32_t hw_index) {
1420   // Watchpoint Value Registers, bitfield definitions
1421   // Bits        Description
1422   // [31:2]      Watchpoint value (word address, i.e., 4-byte aligned)
1423   // [1:0]       RAZ/SBZP
1424   return bits(debug_state.__wvr[hw_index], 31, 0);
1425 }
1426 
1427 //----------------------------------------------------------------------
1428 // Register information definitions for 32 bit ARMV7.
1429 //----------------------------------------------------------------------
1430 enum gpr_regnums {
1431   gpr_r0 = 0,
1432   gpr_r1,
1433   gpr_r2,
1434   gpr_r3,
1435   gpr_r4,
1436   gpr_r5,
1437   gpr_r6,
1438   gpr_r7,
1439   gpr_r8,
1440   gpr_r9,
1441   gpr_r10,
1442   gpr_r11,
1443   gpr_r12,
1444   gpr_sp,
1445   gpr_lr,
1446   gpr_pc,
1447   gpr_cpsr
1448 };
1449 
1450 enum {
1451   vfp_s0 = 0,
1452   vfp_s1,
1453   vfp_s2,
1454   vfp_s3,
1455   vfp_s4,
1456   vfp_s5,
1457   vfp_s6,
1458   vfp_s7,
1459   vfp_s8,
1460   vfp_s9,
1461   vfp_s10,
1462   vfp_s11,
1463   vfp_s12,
1464   vfp_s13,
1465   vfp_s14,
1466   vfp_s15,
1467   vfp_s16,
1468   vfp_s17,
1469   vfp_s18,
1470   vfp_s19,
1471   vfp_s20,
1472   vfp_s21,
1473   vfp_s22,
1474   vfp_s23,
1475   vfp_s24,
1476   vfp_s25,
1477   vfp_s26,
1478   vfp_s27,
1479   vfp_s28,
1480   vfp_s29,
1481   vfp_s30,
1482   vfp_s31,
1483   vfp_d0,
1484   vfp_d1,
1485   vfp_d2,
1486   vfp_d3,
1487   vfp_d4,
1488   vfp_d5,
1489   vfp_d6,
1490   vfp_d7,
1491   vfp_d8,
1492   vfp_d9,
1493   vfp_d10,
1494   vfp_d11,
1495   vfp_d12,
1496   vfp_d13,
1497   vfp_d14,
1498   vfp_d15,
1499   vfp_d16,
1500   vfp_d17,
1501   vfp_d18,
1502   vfp_d19,
1503   vfp_d20,
1504   vfp_d21,
1505   vfp_d22,
1506   vfp_d23,
1507   vfp_d24,
1508   vfp_d25,
1509   vfp_d26,
1510   vfp_d27,
1511   vfp_d28,
1512   vfp_d29,
1513   vfp_d30,
1514   vfp_d31,
1515   vfp_q0,
1516   vfp_q1,
1517   vfp_q2,
1518   vfp_q3,
1519   vfp_q4,
1520   vfp_q5,
1521   vfp_q6,
1522   vfp_q7,
1523   vfp_q8,
1524   vfp_q9,
1525   vfp_q10,
1526   vfp_q11,
1527   vfp_q12,
1528   vfp_q13,
1529   vfp_q14,
1530   vfp_q15,
1531 #if defined(__arm64__) || defined(__aarch64__)
1532   vfp_fpsr,
1533   vfp_fpcr,
1534 #else
1535   vfp_fpscr
1536 #endif
1537 };
1538 
1539 enum {
1540   exc_exception,
1541   exc_fsr,
1542   exc_far,
1543 };
1544 
1545 #define GPR_OFFSET_IDX(idx) (offsetof(DNBArchMachARM::GPR, __r[idx]))
1546 #define GPR_OFFSET_NAME(reg) (offsetof(DNBArchMachARM::GPR, __##reg))
1547 
1548 #define EXC_OFFSET(reg)                                                        \
1549   (offsetof(DNBArchMachARM::EXC, __##reg) +                                    \
1550    offsetof(DNBArchMachARM::Context, exc))
1551 
1552 // These macros will auto define the register name, alt name, register size,
1553 // register offset, encoding, format and native register. This ensures that
1554 // the register state structures are defined correctly and have the correct
1555 // sizes and offsets.
1556 #define DEFINE_GPR_IDX(idx, reg, alt, gen)                                     \
1557   {                                                                            \
1558     e_regSetGPR, gpr_##reg, #reg, alt, Uint, Hex, 4, GPR_OFFSET_IDX(idx),      \
1559         ehframe_##reg, dwarf_##reg, gen, INVALID_NUB_REGNUM, NULL, NULL        \
1560   }
1561 #define DEFINE_GPR_NAME(reg, alt, gen, inval)                                  \
1562   {                                                                            \
1563     e_regSetGPR, gpr_##reg, #reg, alt, Uint, Hex, 4, GPR_OFFSET_NAME(reg),     \
1564         ehframe_##reg, dwarf_##reg, gen, INVALID_NUB_REGNUM, NULL, inval       \
1565   }
1566 
1567 // In case we are debugging to a debug target that the ability to
1568 // change into the protected modes with folded registers (ABT, IRQ,
1569 // FIQ, SYS, USR, etc..), we should invalidate r8-r14 if the CPSR
1570 // gets modified.
1571 
1572 const char *g_invalidate_cpsr[] = {"r8",  "r9", "r10", "r11",
1573                                    "r12", "sp", "lr",  NULL};
1574 
1575 // General purpose registers
1576 const DNBRegisterInfo DNBArchMachARM::g_gpr_registers[] = {
1577     DEFINE_GPR_IDX(0, r0, "arg1", GENERIC_REGNUM_ARG1),
1578     DEFINE_GPR_IDX(1, r1, "arg2", GENERIC_REGNUM_ARG2),
1579     DEFINE_GPR_IDX(2, r2, "arg3", GENERIC_REGNUM_ARG3),
1580     DEFINE_GPR_IDX(3, r3, "arg4", GENERIC_REGNUM_ARG4),
1581     DEFINE_GPR_IDX(4, r4, NULL, INVALID_NUB_REGNUM),
1582     DEFINE_GPR_IDX(5, r5, NULL, INVALID_NUB_REGNUM),
1583     DEFINE_GPR_IDX(6, r6, NULL, INVALID_NUB_REGNUM),
1584     DEFINE_GPR_IDX(7, r7, "fp", GENERIC_REGNUM_FP),
1585     DEFINE_GPR_IDX(8, r8, NULL, INVALID_NUB_REGNUM),
1586     DEFINE_GPR_IDX(9, r9, NULL, INVALID_NUB_REGNUM),
1587     DEFINE_GPR_IDX(10, r10, NULL, INVALID_NUB_REGNUM),
1588     DEFINE_GPR_IDX(11, r11, NULL, INVALID_NUB_REGNUM),
1589     DEFINE_GPR_IDX(12, r12, NULL, INVALID_NUB_REGNUM),
1590     DEFINE_GPR_NAME(sp, "r13", GENERIC_REGNUM_SP, NULL),
1591     DEFINE_GPR_NAME(lr, "r14", GENERIC_REGNUM_RA, NULL),
1592     DEFINE_GPR_NAME(pc, "r15", GENERIC_REGNUM_PC, NULL),
1593     DEFINE_GPR_NAME(cpsr, "flags", GENERIC_REGNUM_FLAGS, g_invalidate_cpsr)};
1594 
1595 const char *g_contained_q0[]{"q0", NULL};
1596 const char *g_contained_q1[]{"q1", NULL};
1597 const char *g_contained_q2[]{"q2", NULL};
1598 const char *g_contained_q3[]{"q3", NULL};
1599 const char *g_contained_q4[]{"q4", NULL};
1600 const char *g_contained_q5[]{"q5", NULL};
1601 const char *g_contained_q6[]{"q6", NULL};
1602 const char *g_contained_q7[]{"q7", NULL};
1603 const char *g_contained_q8[]{"q8", NULL};
1604 const char *g_contained_q9[]{"q9", NULL};
1605 const char *g_contained_q10[]{"q10", NULL};
1606 const char *g_contained_q11[]{"q11", NULL};
1607 const char *g_contained_q12[]{"q12", NULL};
1608 const char *g_contained_q13[]{"q13", NULL};
1609 const char *g_contained_q14[]{"q14", NULL};
1610 const char *g_contained_q15[]{"q15", NULL};
1611 
1612 const char *g_invalidate_q0[]{"q0", "d0", "d1", "s0", "s1", "s2", "s3", NULL};
1613 const char *g_invalidate_q1[]{"q1", "d2", "d3", "s4", "s5", "s6", "s7", NULL};
1614 const char *g_invalidate_q2[]{"q2", "d4", "d5", "s8", "s9", "s10", "s11", NULL};
1615 const char *g_invalidate_q3[]{"q3",  "d6",  "d7",  "s12",
1616                               "s13", "s14", "s15", NULL};
1617 const char *g_invalidate_q4[]{"q4",  "d8",  "d9",  "s16",
1618                               "s17", "s18", "s19", NULL};
1619 const char *g_invalidate_q5[]{"q5",  "d10", "d11", "s20",
1620                               "s21", "s22", "s23", NULL};
1621 const char *g_invalidate_q6[]{"q6",  "d12", "d13", "s24",
1622                               "s25", "s26", "s27", NULL};
1623 const char *g_invalidate_q7[]{"q7",  "d14", "d15", "s28",
1624                               "s29", "s30", "s31", NULL};
1625 const char *g_invalidate_q8[]{"q8", "d16", "d17", NULL};
1626 const char *g_invalidate_q9[]{"q9", "d18", "d19", NULL};
1627 const char *g_invalidate_q10[]{"q10", "d20", "d21", NULL};
1628 const char *g_invalidate_q11[]{"q11", "d22", "d23", NULL};
1629 const char *g_invalidate_q12[]{"q12", "d24", "d25", NULL};
1630 const char *g_invalidate_q13[]{"q13", "d26", "d27", NULL};
1631 const char *g_invalidate_q14[]{"q14", "d28", "d29", NULL};
1632 const char *g_invalidate_q15[]{"q15", "d30", "d31", NULL};
1633 
1634 #define VFP_S_OFFSET_IDX(idx)                                                  \
1635   (((idx) % 4) * 4) // offset into q reg: 0, 4, 8, 12
1636 #define VFP_D_OFFSET_IDX(idx) (((idx) % 2) * 8) // offset into q reg: 0, 8
1637 #define VFP_Q_OFFSET_IDX(idx) (VFP_S_OFFSET_IDX((idx)*4))
1638 
1639 #define VFP_OFFSET_NAME(reg)                                                   \
1640   (offsetof(DNBArchMachARM::FPU, __##reg) +                                    \
1641    offsetof(DNBArchMachARM::Context, vfp))
1642 
1643 #define FLOAT_FORMAT Float
1644 
1645 #define DEFINE_VFP_S_IDX(idx)                                                  \
1646   e_regSetVFP, vfp_s##idx, "s" #idx, NULL, IEEE754, FLOAT_FORMAT, 4,           \
1647       VFP_S_OFFSET_IDX(idx), INVALID_NUB_REGNUM, dwarf_s##idx,                 \
1648       INVALID_NUB_REGNUM, INVALID_NUB_REGNUM
1649 #define DEFINE_VFP_D_IDX(idx)                                                  \
1650   e_regSetVFP, vfp_d##idx, "d" #idx, NULL, IEEE754, FLOAT_FORMAT, 8,           \
1651       VFP_D_OFFSET_IDX(idx), INVALID_NUB_REGNUM, dwarf_d##idx,                 \
1652       INVALID_NUB_REGNUM, INVALID_NUB_REGNUM
1653 #define DEFINE_VFP_Q_IDX(idx)                                                  \
1654   e_regSetVFP, vfp_q##idx, "q" #idx, NULL, Vector, VectorOfUInt8, 16,          \
1655       VFP_Q_OFFSET_IDX(idx), INVALID_NUB_REGNUM, dwarf_q##idx,                 \
1656       INVALID_NUB_REGNUM, INVALID_NUB_REGNUM
1657 
1658 // Floating point registers
1659 const DNBRegisterInfo DNBArchMachARM::g_vfp_registers[] = {
1660     {DEFINE_VFP_S_IDX(0), g_contained_q0, g_invalidate_q0},
1661     {DEFINE_VFP_S_IDX(1), g_contained_q0, g_invalidate_q0},
1662     {DEFINE_VFP_S_IDX(2), g_contained_q0, g_invalidate_q0},
1663     {DEFINE_VFP_S_IDX(3), g_contained_q0, g_invalidate_q0},
1664     {DEFINE_VFP_S_IDX(4), g_contained_q1, g_invalidate_q1},
1665     {DEFINE_VFP_S_IDX(5), g_contained_q1, g_invalidate_q1},
1666     {DEFINE_VFP_S_IDX(6), g_contained_q1, g_invalidate_q1},
1667     {DEFINE_VFP_S_IDX(7), g_contained_q1, g_invalidate_q1},
1668     {DEFINE_VFP_S_IDX(8), g_contained_q2, g_invalidate_q2},
1669     {DEFINE_VFP_S_IDX(9), g_contained_q2, g_invalidate_q2},
1670     {DEFINE_VFP_S_IDX(10), g_contained_q2, g_invalidate_q2},
1671     {DEFINE_VFP_S_IDX(11), g_contained_q2, g_invalidate_q2},
1672     {DEFINE_VFP_S_IDX(12), g_contained_q3, g_invalidate_q3},
1673     {DEFINE_VFP_S_IDX(13), g_contained_q3, g_invalidate_q3},
1674     {DEFINE_VFP_S_IDX(14), g_contained_q3, g_invalidate_q3},
1675     {DEFINE_VFP_S_IDX(15), g_contained_q3, g_invalidate_q3},
1676     {DEFINE_VFP_S_IDX(16), g_contained_q4, g_invalidate_q4},
1677     {DEFINE_VFP_S_IDX(17), g_contained_q4, g_invalidate_q4},
1678     {DEFINE_VFP_S_IDX(18), g_contained_q4, g_invalidate_q4},
1679     {DEFINE_VFP_S_IDX(19), g_contained_q4, g_invalidate_q4},
1680     {DEFINE_VFP_S_IDX(20), g_contained_q5, g_invalidate_q5},
1681     {DEFINE_VFP_S_IDX(21), g_contained_q5, g_invalidate_q5},
1682     {DEFINE_VFP_S_IDX(22), g_contained_q5, g_invalidate_q5},
1683     {DEFINE_VFP_S_IDX(23), g_contained_q5, g_invalidate_q5},
1684     {DEFINE_VFP_S_IDX(24), g_contained_q6, g_invalidate_q6},
1685     {DEFINE_VFP_S_IDX(25), g_contained_q6, g_invalidate_q6},
1686     {DEFINE_VFP_S_IDX(26), g_contained_q6, g_invalidate_q6},
1687     {DEFINE_VFP_S_IDX(27), g_contained_q6, g_invalidate_q6},
1688     {DEFINE_VFP_S_IDX(28), g_contained_q7, g_invalidate_q7},
1689     {DEFINE_VFP_S_IDX(29), g_contained_q7, g_invalidate_q7},
1690     {DEFINE_VFP_S_IDX(30), g_contained_q7, g_invalidate_q7},
1691     {DEFINE_VFP_S_IDX(31), g_contained_q7, g_invalidate_q7},
1692 
1693     {DEFINE_VFP_D_IDX(0), g_contained_q0, g_invalidate_q0},
1694     {DEFINE_VFP_D_IDX(1), g_contained_q0, g_invalidate_q0},
1695     {DEFINE_VFP_D_IDX(2), g_contained_q1, g_invalidate_q1},
1696     {DEFINE_VFP_D_IDX(3), g_contained_q1, g_invalidate_q1},
1697     {DEFINE_VFP_D_IDX(4), g_contained_q2, g_invalidate_q2},
1698     {DEFINE_VFP_D_IDX(5), g_contained_q2, g_invalidate_q2},
1699     {DEFINE_VFP_D_IDX(6), g_contained_q3, g_invalidate_q3},
1700     {DEFINE_VFP_D_IDX(7), g_contained_q3, g_invalidate_q3},
1701     {DEFINE_VFP_D_IDX(8), g_contained_q4, g_invalidate_q4},
1702     {DEFINE_VFP_D_IDX(9), g_contained_q4, g_invalidate_q4},
1703     {DEFINE_VFP_D_IDX(10), g_contained_q5, g_invalidate_q5},
1704     {DEFINE_VFP_D_IDX(11), g_contained_q5, g_invalidate_q5},
1705     {DEFINE_VFP_D_IDX(12), g_contained_q6, g_invalidate_q6},
1706     {DEFINE_VFP_D_IDX(13), g_contained_q6, g_invalidate_q6},
1707     {DEFINE_VFP_D_IDX(14), g_contained_q7, g_invalidate_q7},
1708     {DEFINE_VFP_D_IDX(15), g_contained_q7, g_invalidate_q7},
1709     {DEFINE_VFP_D_IDX(16), g_contained_q8, g_invalidate_q8},
1710     {DEFINE_VFP_D_IDX(17), g_contained_q8, g_invalidate_q8},
1711     {DEFINE_VFP_D_IDX(18), g_contained_q9, g_invalidate_q9},
1712     {DEFINE_VFP_D_IDX(19), g_contained_q9, g_invalidate_q9},
1713     {DEFINE_VFP_D_IDX(20), g_contained_q10, g_invalidate_q10},
1714     {DEFINE_VFP_D_IDX(21), g_contained_q10, g_invalidate_q10},
1715     {DEFINE_VFP_D_IDX(22), g_contained_q11, g_invalidate_q11},
1716     {DEFINE_VFP_D_IDX(23), g_contained_q11, g_invalidate_q11},
1717     {DEFINE_VFP_D_IDX(24), g_contained_q12, g_invalidate_q12},
1718     {DEFINE_VFP_D_IDX(25), g_contained_q12, g_invalidate_q12},
1719     {DEFINE_VFP_D_IDX(26), g_contained_q13, g_invalidate_q13},
1720     {DEFINE_VFP_D_IDX(27), g_contained_q13, g_invalidate_q13},
1721     {DEFINE_VFP_D_IDX(28), g_contained_q14, g_invalidate_q14},
1722     {DEFINE_VFP_D_IDX(29), g_contained_q14, g_invalidate_q14},
1723     {DEFINE_VFP_D_IDX(30), g_contained_q15, g_invalidate_q15},
1724     {DEFINE_VFP_D_IDX(31), g_contained_q15, g_invalidate_q15},
1725 
1726     {DEFINE_VFP_Q_IDX(0), NULL, g_invalidate_q0},
1727     {DEFINE_VFP_Q_IDX(1), NULL, g_invalidate_q1},
1728     {DEFINE_VFP_Q_IDX(2), NULL, g_invalidate_q2},
1729     {DEFINE_VFP_Q_IDX(3), NULL, g_invalidate_q3},
1730     {DEFINE_VFP_Q_IDX(4), NULL, g_invalidate_q4},
1731     {DEFINE_VFP_Q_IDX(5), NULL, g_invalidate_q5},
1732     {DEFINE_VFP_Q_IDX(6), NULL, g_invalidate_q6},
1733     {DEFINE_VFP_Q_IDX(7), NULL, g_invalidate_q7},
1734     {DEFINE_VFP_Q_IDX(8), NULL, g_invalidate_q8},
1735     {DEFINE_VFP_Q_IDX(9), NULL, g_invalidate_q9},
1736     {DEFINE_VFP_Q_IDX(10), NULL, g_invalidate_q10},
1737     {DEFINE_VFP_Q_IDX(11), NULL, g_invalidate_q11},
1738     {DEFINE_VFP_Q_IDX(12), NULL, g_invalidate_q12},
1739     {DEFINE_VFP_Q_IDX(13), NULL, g_invalidate_q13},
1740     {DEFINE_VFP_Q_IDX(14), NULL, g_invalidate_q14},
1741     {DEFINE_VFP_Q_IDX(15), NULL, g_invalidate_q15},
1742 
1743 #if defined(__arm64__) || defined(__aarch64__)
1744     {e_regSetVFP, vfp_fpsr, "fpsr", NULL, Uint, Hex, 4, VFP_OFFSET_NAME(fpsr),
1745      INVALID_NUB_REGNUM, INVALID_NUB_REGNUM, INVALID_NUB_REGNUM,
1746      INVALID_NUB_REGNUM, NULL, NULL},
1747     {e_regSetVFP, vfp_fpcr, "fpcr", NULL, Uint, Hex, 4, VFP_OFFSET_NAME(fpcr),
1748      INVALID_NUB_REGNUM, INVALID_NUB_REGNUM, INVALID_NUB_REGNUM,
1749      INVALID_NUB_REGNUM, NULL, NULL}
1750 #else
1751     {e_regSetVFP, vfp_fpscr, "fpscr", NULL, Uint, Hex, 4,
1752      VFP_OFFSET_NAME(fpscr), INVALID_NUB_REGNUM, INVALID_NUB_REGNUM,
1753      INVALID_NUB_REGNUM, INVALID_NUB_REGNUM, NULL, NULL}
1754 #endif
1755 };
1756 
1757 // Exception registers
1758 
1759 const DNBRegisterInfo DNBArchMachARM::g_exc_registers[] = {
1760     {e_regSetVFP, exc_exception, "exception", NULL, Uint, Hex, 4,
1761      EXC_OFFSET(exception), INVALID_NUB_REGNUM, INVALID_NUB_REGNUM,
1762      INVALID_NUB_REGNUM, INVALID_NUB_REGNUM},
1763     {e_regSetVFP, exc_fsr, "fsr", NULL, Uint, Hex, 4, EXC_OFFSET(fsr),
1764      INVALID_NUB_REGNUM, INVALID_NUB_REGNUM, INVALID_NUB_REGNUM,
1765      INVALID_NUB_REGNUM},
1766     {e_regSetVFP, exc_far, "far", NULL, Uint, Hex, 4, EXC_OFFSET(far),
1767      INVALID_NUB_REGNUM, INVALID_NUB_REGNUM, INVALID_NUB_REGNUM,
1768      INVALID_NUB_REGNUM}};
1769 
1770 // Number of registers in each register set
1771 const size_t DNBArchMachARM::k_num_gpr_registers =
1772     sizeof(g_gpr_registers) / sizeof(DNBRegisterInfo);
1773 const size_t DNBArchMachARM::k_num_vfp_registers =
1774     sizeof(g_vfp_registers) / sizeof(DNBRegisterInfo);
1775 const size_t DNBArchMachARM::k_num_exc_registers =
1776     sizeof(g_exc_registers) / sizeof(DNBRegisterInfo);
1777 const size_t DNBArchMachARM::k_num_all_registers =
1778     k_num_gpr_registers + k_num_vfp_registers + k_num_exc_registers;
1779 
1780 //----------------------------------------------------------------------
1781 // Register set definitions. The first definitions at register set index
1782 // of zero is for all registers, followed by other registers sets. The
1783 // register information for the all register set need not be filled in.
1784 //----------------------------------------------------------------------
1785 const DNBRegisterSetInfo DNBArchMachARM::g_reg_sets[] = {
1786     {"ARM Registers", NULL, k_num_all_registers},
1787     {"General Purpose Registers", g_gpr_registers, k_num_gpr_registers},
1788     {"Floating Point Registers", g_vfp_registers, k_num_vfp_registers},
1789     {"Exception State Registers", g_exc_registers, k_num_exc_registers}};
1790 // Total number of register sets for this architecture
1791 const size_t DNBArchMachARM::k_num_register_sets =
1792     sizeof(g_reg_sets) / sizeof(DNBRegisterSetInfo);
1793 
1794 const DNBRegisterSetInfo *
1795 DNBArchMachARM::GetRegisterSetInfo(nub_size_t *num_reg_sets) {
1796   *num_reg_sets = k_num_register_sets;
1797   return g_reg_sets;
1798 }
1799 
1800 bool DNBArchMachARM::GetRegisterValue(uint32_t set, uint32_t reg,
1801                                       DNBRegisterValue *value) {
1802   if (set == REGISTER_SET_GENERIC) {
1803     switch (reg) {
1804     case GENERIC_REGNUM_PC: // Program Counter
1805       set = e_regSetGPR;
1806       reg = gpr_pc;
1807       break;
1808 
1809     case GENERIC_REGNUM_SP: // Stack Pointer
1810       set = e_regSetGPR;
1811       reg = gpr_sp;
1812       break;
1813 
1814     case GENERIC_REGNUM_FP: // Frame Pointer
1815       set = e_regSetGPR;
1816       reg = gpr_r7; // is this the right reg?
1817       break;
1818 
1819     case GENERIC_REGNUM_RA: // Return Address
1820       set = e_regSetGPR;
1821       reg = gpr_lr;
1822       break;
1823 
1824     case GENERIC_REGNUM_FLAGS: // Processor flags register
1825       set = e_regSetGPR;
1826       reg = gpr_cpsr;
1827       break;
1828 
1829     default:
1830       return false;
1831     }
1832   }
1833 
1834   if (GetRegisterState(set, false) != KERN_SUCCESS)
1835     return false;
1836 
1837   const DNBRegisterInfo *regInfo = m_thread->GetRegisterInfo(set, reg);
1838   if (regInfo) {
1839     value->info = *regInfo;
1840     switch (set) {
1841     case e_regSetGPR:
1842       if (reg < k_num_gpr_registers) {
1843         value->value.uint32 = m_state.context.gpr.__r[reg];
1844         return true;
1845       }
1846       break;
1847 
1848     case e_regSetVFP:
1849       // "reg" is an index into the floating point register set at this point.
1850       // We need to translate it up so entry 0 in the fp reg set is the same as
1851       // vfp_s0
1852       // in the enumerated values for case statement below.
1853       if (reg >= vfp_s0 && reg <= vfp_s31) {
1854 #if defined(__arm64__) || defined(__aarch64__)
1855         uint32_t *s_reg =
1856             ((uint32_t *)&m_state.context.vfp.__v[0]) + (reg - vfp_s0);
1857         memcpy(&value->value.v_uint8, s_reg, 4);
1858 #else
1859         value->value.uint32 = m_state.context.vfp.__r[reg];
1860 #endif
1861         return true;
1862       } else if (reg >= vfp_d0 && reg <= vfp_d31) {
1863 #if defined(__arm64__) || defined(__aarch64__)
1864         uint64_t *d_reg =
1865             ((uint64_t *)&m_state.context.vfp.__v[0]) + (reg - vfp_d0);
1866         memcpy(&value->value.v_uint8, d_reg, 8);
1867 #else
1868         uint32_t d_reg_idx = reg - vfp_d0;
1869         uint32_t s_reg_idx = d_reg_idx * 2;
1870         value->value.v_sint32[0] = m_state.context.vfp.__r[s_reg_idx + 0];
1871         value->value.v_sint32[1] = m_state.context.vfp.__r[s_reg_idx + 1];
1872 #endif
1873         return true;
1874       } else if (reg >= vfp_q0 && reg <= vfp_q15) {
1875 #if defined(__arm64__) || defined(__aarch64__)
1876         memcpy(&value->value.v_uint8,
1877                (uint8_t *)&m_state.context.vfp.__v[reg - vfp_q0], 16);
1878 #else
1879         uint32_t s_reg_idx = (reg - vfp_q0) * 4;
1880         memcpy(&value->value.v_uint8,
1881                (uint8_t *)&m_state.context.vfp.__r[s_reg_idx], 16);
1882 #endif
1883         return true;
1884       }
1885 #if defined(__arm64__) || defined(__aarch64__)
1886       else if (reg == vfp_fpsr) {
1887         value->value.uint32 = m_state.context.vfp.__fpsr;
1888         return true;
1889       } else if (reg == vfp_fpcr) {
1890         value->value.uint32 = m_state.context.vfp.__fpcr;
1891         return true;
1892       }
1893 #else
1894       else if (reg == vfp_fpscr) {
1895         value->value.uint32 = m_state.context.vfp.__fpscr;
1896         return true;
1897       }
1898 #endif
1899       break;
1900 
1901     case e_regSetEXC:
1902       if (reg < k_num_exc_registers) {
1903         value->value.uint32 = (&m_state.context.exc.__exception)[reg];
1904         return true;
1905       }
1906       break;
1907     }
1908   }
1909   return false;
1910 }
1911 
1912 bool DNBArchMachARM::SetRegisterValue(uint32_t set, uint32_t reg,
1913                                       const DNBRegisterValue *value) {
1914   if (set == REGISTER_SET_GENERIC) {
1915     switch (reg) {
1916     case GENERIC_REGNUM_PC: // Program Counter
1917       set = e_regSetGPR;
1918       reg = gpr_pc;
1919       break;
1920 
1921     case GENERIC_REGNUM_SP: // Stack Pointer
1922       set = e_regSetGPR;
1923       reg = gpr_sp;
1924       break;
1925 
1926     case GENERIC_REGNUM_FP: // Frame Pointer
1927       set = e_regSetGPR;
1928       reg = gpr_r7;
1929       break;
1930 
1931     case GENERIC_REGNUM_RA: // Return Address
1932       set = e_regSetGPR;
1933       reg = gpr_lr;
1934       break;
1935 
1936     case GENERIC_REGNUM_FLAGS: // Processor flags register
1937       set = e_regSetGPR;
1938       reg = gpr_cpsr;
1939       break;
1940 
1941     default:
1942       return false;
1943     }
1944   }
1945 
1946   if (GetRegisterState(set, false) != KERN_SUCCESS)
1947     return false;
1948 
1949   bool success = false;
1950   const DNBRegisterInfo *regInfo = m_thread->GetRegisterInfo(set, reg);
1951   if (regInfo) {
1952     switch (set) {
1953     case e_regSetGPR:
1954       if (reg < k_num_gpr_registers) {
1955         m_state.context.gpr.__r[reg] = value->value.uint32;
1956         success = true;
1957       }
1958       break;
1959 
1960     case e_regSetVFP:
1961       // "reg" is an index into the floating point register set at this point.
1962       // We need to translate it up so entry 0 in the fp reg set is the same as
1963       // vfp_s0
1964       // in the enumerated values for case statement below.
1965       if (reg >= vfp_s0 && reg <= vfp_s31) {
1966 #if defined(__arm64__) || defined(__aarch64__)
1967         uint32_t *s_reg =
1968             ((uint32_t *)&m_state.context.vfp.__v[0]) + (reg - vfp_s0);
1969         memcpy(s_reg, &value->value.v_uint8, 4);
1970 #else
1971         m_state.context.vfp.__r[reg] = value->value.uint32;
1972 #endif
1973         success = true;
1974       } else if (reg >= vfp_d0 && reg <= vfp_d31) {
1975 #if defined(__arm64__) || defined(__aarch64__)
1976         uint64_t *d_reg =
1977             ((uint64_t *)&m_state.context.vfp.__v[0]) + (reg - vfp_d0);
1978         memcpy(d_reg, &value->value.v_uint8, 8);
1979 #else
1980         uint32_t d_reg_idx = reg - vfp_d0;
1981         uint32_t s_reg_idx = d_reg_idx * 2;
1982         m_state.context.vfp.__r[s_reg_idx + 0] = value->value.v_sint32[0];
1983         m_state.context.vfp.__r[s_reg_idx + 1] = value->value.v_sint32[1];
1984 #endif
1985         success = true;
1986       } else if (reg >= vfp_q0 && reg <= vfp_q15) {
1987 #if defined(__arm64__) || defined(__aarch64__)
1988         memcpy((uint8_t *)&m_state.context.vfp.__v[reg - vfp_q0],
1989                &value->value.v_uint8, 16);
1990 #else
1991         uint32_t s_reg_idx = (reg - vfp_q0) * 4;
1992         memcpy((uint8_t *)&m_state.context.vfp.__r[s_reg_idx],
1993                &value->value.v_uint8, 16);
1994 #endif
1995         success = true;
1996       }
1997 #if defined(__arm64__) || defined(__aarch64__)
1998       else if (reg == vfp_fpsr) {
1999         m_state.context.vfp.__fpsr = value->value.uint32;
2000         success = true;
2001       } else if (reg == vfp_fpcr) {
2002         m_state.context.vfp.__fpcr = value->value.uint32;
2003         success = true;
2004       }
2005 #else
2006       else if (reg == vfp_fpscr) {
2007         m_state.context.vfp.__fpscr = value->value.uint32;
2008         success = true;
2009       }
2010 #endif
2011       break;
2012 
2013     case e_regSetEXC:
2014       if (reg < k_num_exc_registers) {
2015         (&m_state.context.exc.__exception)[reg] = value->value.uint32;
2016         success = true;
2017       }
2018       break;
2019     }
2020   }
2021   if (success)
2022     return SetRegisterState(set) == KERN_SUCCESS;
2023   return false;
2024 }
2025 
2026 kern_return_t DNBArchMachARM::GetRegisterState(int set, bool force) {
2027   switch (set) {
2028   case e_regSetALL:
2029     return GetGPRState(force) | GetVFPState(force) | GetEXCState(force) |
2030            GetDBGState(force);
2031   case e_regSetGPR:
2032     return GetGPRState(force);
2033   case e_regSetVFP:
2034     return GetVFPState(force);
2035   case e_regSetEXC:
2036     return GetEXCState(force);
2037   case e_regSetDBG:
2038     return GetDBGState(force);
2039   default:
2040     break;
2041   }
2042   return KERN_INVALID_ARGUMENT;
2043 }
2044 
2045 kern_return_t DNBArchMachARM::SetRegisterState(int set) {
2046   // Make sure we have a valid context to set.
2047   kern_return_t err = GetRegisterState(set, false);
2048   if (err != KERN_SUCCESS)
2049     return err;
2050 
2051   switch (set) {
2052   case e_regSetALL:
2053     return SetGPRState() | SetVFPState() | SetEXCState() | SetDBGState(false);
2054   case e_regSetGPR:
2055     return SetGPRState();
2056   case e_regSetVFP:
2057     return SetVFPState();
2058   case e_regSetEXC:
2059     return SetEXCState();
2060   case e_regSetDBG:
2061     return SetDBGState(false);
2062   default:
2063     break;
2064   }
2065   return KERN_INVALID_ARGUMENT;
2066 }
2067 
2068 bool DNBArchMachARM::RegisterSetStateIsValid(int set) const {
2069   return m_state.RegsAreValid(set);
2070 }
2071 
2072 nub_size_t DNBArchMachARM::GetRegisterContext(void *buf, nub_size_t buf_len) {
2073   nub_size_t size = sizeof(m_state.context.gpr) + sizeof(m_state.context.vfp) +
2074                     sizeof(m_state.context.exc);
2075 
2076   if (buf && buf_len) {
2077     if (size > buf_len)
2078       size = buf_len;
2079 
2080     bool force = false;
2081     if (GetGPRState(force) | GetVFPState(force) | GetEXCState(force))
2082       return 0;
2083 
2084     // Copy each struct individually to avoid any padding that might be between
2085     // the structs in m_state.context
2086     uint8_t *p = (uint8_t *)buf;
2087     ::memcpy(p, &m_state.context.gpr, sizeof(m_state.context.gpr));
2088     p += sizeof(m_state.context.gpr);
2089     ::memcpy(p, &m_state.context.vfp, sizeof(m_state.context.vfp));
2090     p += sizeof(m_state.context.vfp);
2091     ::memcpy(p, &m_state.context.exc, sizeof(m_state.context.exc));
2092     p += sizeof(m_state.context.exc);
2093 
2094     size_t bytes_written = p - (uint8_t *)buf;
2095     UNUSED_IF_ASSERT_DISABLED(bytes_written);
2096     assert(bytes_written == size);
2097   }
2098   DNBLogThreadedIf(
2099       LOG_THREAD,
2100       "DNBArchMachARM::GetRegisterContext (buf = %p, len = %llu) => %llu", buf,
2101       (uint64_t)buf_len, (uint64_t)size);
2102   // Return the size of the register context even if NULL was passed in
2103   return size;
2104 }
2105 
2106 nub_size_t DNBArchMachARM::SetRegisterContext(const void *buf,
2107                                               nub_size_t buf_len) {
2108   nub_size_t size = sizeof(m_state.context.gpr) + sizeof(m_state.context.vfp) +
2109                     sizeof(m_state.context.exc);
2110 
2111   if (buf == NULL || buf_len == 0)
2112     size = 0;
2113 
2114   if (size) {
2115     if (size > buf_len)
2116       size = buf_len;
2117 
2118     // Copy each struct individually to avoid any padding that might be between
2119     // the structs in m_state.context
2120     uint8_t *p = (uint8_t *)buf;
2121     ::memcpy(&m_state.context.gpr, p, sizeof(m_state.context.gpr));
2122     p += sizeof(m_state.context.gpr);
2123     ::memcpy(&m_state.context.vfp, p, sizeof(m_state.context.vfp));
2124     p += sizeof(m_state.context.vfp);
2125     ::memcpy(&m_state.context.exc, p, sizeof(m_state.context.exc));
2126     p += sizeof(m_state.context.exc);
2127 
2128     size_t bytes_written = p - (uint8_t *)buf;
2129     UNUSED_IF_ASSERT_DISABLED(bytes_written);
2130     assert(bytes_written == size);
2131 
2132     if (SetGPRState() | SetVFPState() | SetEXCState())
2133       return 0;
2134   }
2135   DNBLogThreadedIf(
2136       LOG_THREAD,
2137       "DNBArchMachARM::SetRegisterContext (buf = %p, len = %llu) => %llu", buf,
2138       (uint64_t)buf_len, (uint64_t)size);
2139   return size;
2140 }
2141 
2142 uint32_t DNBArchMachARM::SaveRegisterState() {
2143   kern_return_t kret = ::thread_abort_safely(m_thread->MachPortNumber());
2144   DNBLogThreadedIf(
2145       LOG_THREAD, "thread = 0x%4.4x calling thread_abort_safely (tid) => %u "
2146                   "(SetGPRState() for stop_count = %u)",
2147       m_thread->MachPortNumber(), kret, m_thread->Process()->StopCount());
2148 
2149   // Always re-read the registers because above we call thread_abort_safely();
2150   bool force = true;
2151 
2152   if ((kret = GetGPRState(force)) != KERN_SUCCESS) {
2153     DNBLogThreadedIf(LOG_THREAD, "DNBArchMachARM::SaveRegisterState () error: "
2154                                  "GPR regs failed to read: %u ",
2155                      kret);
2156   } else if ((kret = GetVFPState(force)) != KERN_SUCCESS) {
2157     DNBLogThreadedIf(LOG_THREAD, "DNBArchMachARM::SaveRegisterState () error: "
2158                                  "%s regs failed to read: %u",
2159                      "VFP", kret);
2160   } else {
2161     const uint32_t save_id = GetNextRegisterStateSaveID();
2162     m_saved_register_states[save_id] = m_state.context;
2163     return save_id;
2164   }
2165   return UINT32_MAX;
2166 }
2167 
2168 bool DNBArchMachARM::RestoreRegisterState(uint32_t save_id) {
2169   SaveRegisterStates::iterator pos = m_saved_register_states.find(save_id);
2170   if (pos != m_saved_register_states.end()) {
2171     m_state.context.gpr = pos->second.gpr;
2172     m_state.context.vfp = pos->second.vfp;
2173     kern_return_t kret;
2174     bool success = true;
2175     if ((kret = SetGPRState()) != KERN_SUCCESS) {
2176       DNBLogThreadedIf(LOG_THREAD, "DNBArchMachARM::RestoreRegisterState "
2177                                    "(save_id = %u) error: GPR regs failed to "
2178                                    "write: %u",
2179                        save_id, kret);
2180       success = false;
2181     } else if ((kret = SetVFPState()) != KERN_SUCCESS) {
2182       DNBLogThreadedIf(LOG_THREAD, "DNBArchMachARM::RestoreRegisterState "
2183                                    "(save_id = %u) error: %s regs failed to "
2184                                    "write: %u",
2185                        save_id, "VFP", kret);
2186       success = false;
2187     }
2188     m_saved_register_states.erase(pos);
2189     return success;
2190   }
2191   return false;
2192 }
2193 
2194 #endif // #if defined (__arm__)
2195