1 //===-- NativeRegisterContextLinux_arm.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 #include "NativeRegisterContextLinux_arm.h"
11 
12 #include "lldb/lldb-private-forward.h"
13 #include "lldb/Core/DataBufferHeap.h"
14 #include "lldb/Core/Error.h"
15 #include "lldb/Core/RegisterValue.h"
16 #include "lldb/Host/common/NativeProcessProtocol.h"
17 #include "lldb/Host/common/NativeThreadProtocol.h"
18 #include "Plugins/Process/Linux/NativeProcessLinux.h"
19 
20 #define REG_CONTEXT_SIZE (GetGPRSize() + sizeof (m_fpr))
21 
22 using namespace lldb;
23 using namespace lldb_private;
24 using namespace lldb_private::process_linux;
25 
26 // arm general purpose registers.
27 static const uint32_t g_gpr_regnums_arm[] =
28 {
29     gpr_r0_arm,
30     gpr_r1_arm,
31     gpr_r2_arm,
32     gpr_r3_arm,
33     gpr_r4_arm,
34     gpr_r5_arm,
35     gpr_r6_arm,
36     gpr_r7_arm,
37     gpr_r8_arm,
38     gpr_r9_arm,
39     gpr_r10_arm,
40     gpr_r11_arm,
41     gpr_r12_arm,
42     gpr_sp_arm,
43     gpr_lr_arm,
44     gpr_pc_arm,
45     gpr_cpsr_arm,
46     LLDB_INVALID_REGNUM // register sets need to end with this flag
47 };
48 static_assert(((sizeof g_gpr_regnums_arm / sizeof g_gpr_regnums_arm[0]) - 1) == k_num_gpr_registers_arm, \
49               "g_gpr_regnums_arm has wrong number of register infos");
50 
51 // arm floating point registers.
52 static const uint32_t g_fpu_regnums_arm[] =
53 {
54     fpu_s0_arm,
55     fpu_s1_arm,
56     fpu_s2_arm,
57     fpu_s3_arm,
58     fpu_s4_arm,
59     fpu_s5_arm,
60     fpu_s6_arm,
61     fpu_s7_arm,
62     fpu_s8_arm,
63     fpu_s9_arm,
64     fpu_s10_arm,
65     fpu_s11_arm,
66     fpu_s12_arm,
67     fpu_s13_arm,
68     fpu_s14_arm,
69     fpu_s15_arm,
70     fpu_s16_arm,
71     fpu_s17_arm,
72     fpu_s18_arm,
73     fpu_s19_arm,
74     fpu_s20_arm,
75     fpu_s21_arm,
76     fpu_s22_arm,
77     fpu_s23_arm,
78     fpu_s24_arm,
79     fpu_s25_arm,
80     fpu_s26_arm,
81     fpu_s27_arm,
82     fpu_s28_arm,
83     fpu_s29_arm,
84     fpu_s30_arm,
85     fpu_s31_arm,
86     fpu_fpscr_arm,
87     LLDB_INVALID_REGNUM // register sets need to end with this flag
88 };
89 static_assert(((sizeof g_fpu_regnums_arm / sizeof g_fpu_regnums_arm[0]) - 1) == k_num_fpr_registers_arm, \
90               "g_fpu_regnums_arm has wrong number of register infos");
91 
92 namespace {
93     // Number of register sets provided by this context.
94     enum
95     {
96         k_num_register_sets = 2
97     };
98 }
99 
100 // Register sets for arm.
101 static const RegisterSet
102 g_reg_sets_arm[k_num_register_sets] =
103 {
104     { "General Purpose Registers",  "gpr", k_num_gpr_registers_arm, g_gpr_regnums_arm },
105     { "Floating Point Registers",   "fpu", k_num_fpr_registers_arm, g_fpu_regnums_arm }
106 };
107 
108 NativeRegisterContextLinux_arm::NativeRegisterContextLinux_arm (
109         NativeThreadProtocol &native_thread,
110         uint32_t concrete_frame_idx,
111         RegisterInfoInterface *reg_info_interface_p) :
112     NativeRegisterContextRegisterInfo (native_thread, concrete_frame_idx, reg_info_interface_p)
113 {
114     switch (reg_info_interface_p->m_target_arch.GetMachine())
115     {
116         case llvm::Triple::arm:
117             m_reg_info.num_registers     = k_num_registers_arm;
118             m_reg_info.num_gpr_registers = k_num_gpr_registers_arm;
119             m_reg_info.num_fpr_registers = k_num_fpr_registers_arm;
120             m_reg_info.last_gpr          = k_last_gpr_arm;
121             m_reg_info.first_fpr         = k_first_fpr_arm;
122             m_reg_info.last_fpr          = k_last_fpr_arm;
123             m_reg_info.first_fpr_v       = fpu_s0_arm;
124             m_reg_info.last_fpr_v        = fpu_s31_arm;
125             m_reg_info.gpr_flags         = gpr_cpsr_arm;
126             break;
127         default:
128             assert(false && "Unhandled target architecture.");
129             break;
130     }
131 
132     ::memset(&m_fpr, 0, sizeof (m_fpr));
133     ::memset(&m_gpr_arm, 0, sizeof (m_gpr_arm));
134 }
135 
136 uint32_t
137 NativeRegisterContextLinux_arm::GetRegisterSetCount () const
138 {
139     return k_num_register_sets;
140 }
141 
142 const RegisterSet *
143 NativeRegisterContextLinux_arm::GetRegisterSet (uint32_t set_index) const
144 {
145     if (set_index < k_num_register_sets)
146         return &g_reg_sets_arm[set_index];
147 
148     return nullptr;
149 }
150 
151 Error
152 NativeRegisterContextLinux_arm::ReadRegister (const RegisterInfo *reg_info, RegisterValue &reg_value)
153 {
154     Error error;
155 
156     if (!reg_info)
157     {
158         error.SetErrorString ("reg_info NULL");
159         return error;
160     }
161 
162     const uint32_t reg = reg_info->kinds[lldb::eRegisterKindLLDB];
163 
164     if (IsFPR(reg))
165     {
166         if (!ReadFPR())
167         {
168             error.SetErrorString ("failed to read floating point register");
169             return error;
170         }
171     }
172     else
173     {
174         uint32_t full_reg = reg;
175         bool is_subreg = reg_info->invalidate_regs && (reg_info->invalidate_regs[0] != LLDB_INVALID_REGNUM);
176 
177         if (is_subreg)
178         {
179             // Read the full aligned 64-bit register.
180             full_reg = reg_info->invalidate_regs[0];
181         }
182 
183         error = ReadRegisterRaw(full_reg, reg_value);
184 
185         if (error.Success ())
186         {
187             // If our read was not aligned (for ah,bh,ch,dh), shift our returned value one byte to the right.
188             if (is_subreg && (reg_info->byte_offset & 0x1))
189                 reg_value.SetUInt64(reg_value.GetAsUInt64() >> 8);
190 
191             // If our return byte size was greater than the return value reg size, then
192             // use the type specified by reg_info rather than the uint64_t default
193             if (reg_value.GetByteSize() > reg_info->byte_size)
194                 reg_value.SetType(reg_info);
195         }
196         return error;
197     }
198 
199     // Get pointer to m_fpr variable and set the data from it.
200     assert (reg_info->byte_offset < sizeof m_fpr);
201     uint8_t *src = (uint8_t *)&m_fpr + reg_info->byte_offset;
202     switch (reg_info->byte_size)
203     {
204         case 2:
205             reg_value.SetUInt16(*(uint16_t *)src);
206             break;
207         case 4:
208             reg_value.SetUInt32(*(uint32_t *)src);
209             break;
210         case 8:
211             reg_value.SetUInt64(*(uint64_t *)src);
212             break;
213         default:
214             assert(false && "Unhandled data size.");
215             error.SetErrorStringWithFormat ("unhandled byte size: %" PRIu32, reg_info->byte_size);
216             break;
217     }
218 
219     return error;
220 }
221 
222 Error
223 NativeRegisterContextLinux_arm::WriteRegister (const RegisterInfo *reg_info, const RegisterValue &reg_value)
224 {
225     if (!reg_info)
226         return Error ("reg_info NULL");
227 
228     const uint32_t reg_index = reg_info->kinds[lldb::eRegisterKindLLDB];
229     if (reg_index == LLDB_INVALID_REGNUM)
230         return Error ("no lldb regnum for %s", reg_info && reg_info->name ? reg_info->name : "<unknown register>");
231 
232     if (IsGPR(reg_index))
233         return WriteRegisterRaw(reg_index, reg_value);
234 
235     if (IsFPR(reg_index))
236     {
237         // Get pointer to m_fpr variable and set the data to it.
238         assert (reg_info->byte_offset < sizeof(m_fpr));
239         uint8_t *dst = (uint8_t *)&m_fpr + reg_info->byte_offset;
240         switch (reg_info->byte_size)
241         {
242             case 2:
243                 *(uint16_t *)dst = reg_value.GetAsUInt16();
244                 break;
245             case 4:
246                 *(uint32_t *)dst = reg_value.GetAsUInt32();
247                 break;
248             case 8:
249                 *(uint64_t *)dst = reg_value.GetAsUInt64();
250                 break;
251             default:
252                 assert(false && "Unhandled data size.");
253                 return Error ("unhandled register data size %" PRIu32, reg_info->byte_size);
254         }
255 
256         if (!WriteFPR())
257         {
258             return Error ("NativeRegisterContextLinux_arm::WriteRegister: WriteFPR failed");
259         }
260 
261         return Error ();
262     }
263 
264     return Error ("failed - register wasn't recognized to be a GPR or an FPR, write strategy unknown");
265 }
266 
267 Error
268 NativeRegisterContextLinux_arm::ReadAllRegisterValues (lldb::DataBufferSP &data_sp)
269 {
270     Error error;
271 
272     data_sp.reset (new DataBufferHeap (REG_CONTEXT_SIZE, 0));
273     if (!data_sp)
274         return Error ("failed to allocate DataBufferHeap instance of size %" PRIu64, (uint64_t)REG_CONTEXT_SIZE);
275 
276     if (!ReadGPR ())
277     {
278         error.SetErrorString ("ReadGPR() failed");
279         return error;
280     }
281 
282     if (!ReadFPR ())
283     {
284         error.SetErrorString ("ReadFPR() failed");
285         return error;
286     }
287 
288     uint8_t *dst = data_sp->GetBytes ();
289     if (dst == nullptr)
290     {
291         error.SetErrorStringWithFormat ("DataBufferHeap instance of size %" PRIu64 " returned a null pointer", (uint64_t)REG_CONTEXT_SIZE);
292         return error;
293     }
294 
295     ::memcpy (dst, &m_gpr_arm, GetGPRSize());
296     dst += GetGPRSize();
297     ::memcpy (dst, &m_fpr, sizeof(m_fpr));
298 
299     return error;
300 }
301 
302 Error
303 NativeRegisterContextLinux_arm::WriteAllRegisterValues (const lldb::DataBufferSP &data_sp)
304 {
305     Error error;
306 
307     if (!data_sp)
308     {
309         error.SetErrorStringWithFormat ("NativeRegisterContextLinux_x86_64::%s invalid data_sp provided", __FUNCTION__);
310         return error;
311     }
312 
313     if (data_sp->GetByteSize () != REG_CONTEXT_SIZE)
314     {
315         error.SetErrorStringWithFormat ("NativeRegisterContextLinux_x86_64::%s data_sp contained mismatched data size, expected %" PRIu64 ", actual %" PRIu64, __FUNCTION__, (uint64_t)REG_CONTEXT_SIZE, data_sp->GetByteSize ());
316         return error;
317     }
318 
319 
320     uint8_t *src = data_sp->GetBytes ();
321     if (src == nullptr)
322     {
323         error.SetErrorStringWithFormat ("NativeRegisterContextLinux_x86_64::%s DataBuffer::GetBytes() returned a null pointer", __FUNCTION__);
324         return error;
325     }
326     ::memcpy (&m_gpr_arm, src, GetRegisterInfoInterface ().GetGPRSize ());
327 
328     if (!WriteGPR ())
329     {
330         error.SetErrorStringWithFormat ("NativeRegisterContextLinux_x86_64::%s WriteGPR() failed", __FUNCTION__);
331         return error;
332     }
333 
334     src += GetRegisterInfoInterface ().GetGPRSize ();
335     ::memcpy (&m_fpr, src, sizeof(m_fpr));
336 
337     if (!WriteFPR ())
338     {
339         error.SetErrorStringWithFormat ("NativeRegisterContextLinux_x86_64::%s WriteFPR() failed", __FUNCTION__);
340         return error;
341     }
342 
343     return error;
344 }
345 
346 Error
347 NativeRegisterContextLinux_arm::WriteRegisterRaw (uint32_t reg_index, const RegisterValue &reg_value)
348 {
349     Error error;
350 
351     uint32_t reg_to_write = reg_index;
352     RegisterValue value_to_write = reg_value;
353 
354     // Check if this is a subregister of a full register.
355     const RegisterInfo *reg_info = GetRegisterInfoAtIndex(reg_index);
356     if (reg_info->invalidate_regs && (reg_info->invalidate_regs[0] != LLDB_INVALID_REGNUM))
357     {
358         RegisterValue full_value;
359         uint32_t full_reg = reg_info->invalidate_regs[0];
360         const RegisterInfo *full_reg_info = GetRegisterInfoAtIndex(full_reg);
361 
362         // Read the full register.
363         error = ReadRegister(full_reg_info, full_value);
364         if (error.Fail ())
365             return error;
366 
367         lldb::ByteOrder byte_order = GetByteOrder();
368         uint8_t dst[RegisterValue::kMaxRegisterByteSize];
369 
370         // Get the bytes for the full register.
371         const uint32_t dest_size = full_value.GetAsMemoryData (full_reg_info,
372                                                                dst,
373                                                                sizeof(dst),
374                                                                byte_order,
375                                                                error);
376         if (error.Success() && dest_size)
377         {
378             uint8_t src[RegisterValue::kMaxRegisterByteSize];
379 
380             // Get the bytes for the source data.
381             const uint32_t src_size = reg_value.GetAsMemoryData (reg_info, src, sizeof(src), byte_order, error);
382             if (error.Success() && src_size && (src_size < dest_size))
383             {
384                 // Copy the src bytes to the destination.
385                 memcpy (dst + (reg_info->byte_offset & 0x1), src, src_size);
386                 // Set this full register as the value to write.
387                 value_to_write.SetBytes(dst, full_value.GetByteSize(), byte_order);
388                 value_to_write.SetType(full_reg_info);
389                 reg_to_write = full_reg;
390             }
391         }
392     }
393 
394     NativeProcessProtocolSP process_sp (m_thread.GetProcess ());
395     if (!process_sp)
396     {
397         error.SetErrorString ("NativeProcessProtocol is NULL");
398         return error;
399     }
400 
401     const RegisterInfo *const register_to_write_info_p = GetRegisterInfoAtIndex (reg_to_write);
402     assert (register_to_write_info_p && "register to write does not have valid RegisterInfo");
403     if (!register_to_write_info_p)
404     {
405         error.SetErrorStringWithFormat ("NativeRegisterContextLinux_arm::%s failed to get RegisterInfo for write register index %" PRIu32, __FUNCTION__, reg_to_write);
406         return error;
407     }
408 
409     NativeProcessLinux *const process_p = reinterpret_cast<NativeProcessLinux*> (process_sp.get ());
410     return process_p->WriteRegisterValue(m_thread.GetID(),
411                                          register_to_write_info_p->byte_offset,
412                                          register_to_write_info_p->name,
413                                          value_to_write);
414 }
415 
416 Error
417 NativeRegisterContextLinux_arm::ReadRegisterRaw (uint32_t reg_index, RegisterValue &reg_value)
418 {
419     Error error;
420     const RegisterInfo *const reg_info = GetRegisterInfoAtIndex (reg_index);
421     if (!reg_info)
422     {
423         error.SetErrorStringWithFormat ("register %" PRIu32 " not found", reg_index);
424         return error;
425     }
426 
427     NativeProcessProtocolSP process_sp (m_thread.GetProcess ());
428     if (!process_sp)
429     {
430         error.SetErrorString ("NativeProcessProtocol is NULL");
431         return error;
432     }
433 
434     NativeProcessLinux *const process_p = reinterpret_cast<NativeProcessLinux*> (process_sp.get ());
435     return process_p->ReadRegisterValue(m_thread.GetID(),
436                                         reg_info->byte_offset,
437                                         reg_info->name,
438                                         reg_info->byte_size,
439                                         reg_value);
440 }
441 
442 bool
443 NativeRegisterContextLinux_arm::IsGPR(unsigned reg) const
444 {
445     return reg <= m_reg_info.last_gpr;   // GPR's come first.
446 }
447 
448 bool
449 NativeRegisterContextLinux_arm::ReadGPR()
450 {
451     NativeProcessProtocolSP process_sp (m_thread.GetProcess ());
452     if (!process_sp)
453         return false;
454     NativeProcessLinux *const process_p = reinterpret_cast<NativeProcessLinux*> (process_sp.get ());
455 
456     return process_p->ReadGPR (m_thread.GetID (), &m_gpr_arm, GetRegisterInfoInterface ().GetGPRSize ()).Success();
457 }
458 
459 bool
460 NativeRegisterContextLinux_arm::WriteGPR()
461 {
462     NativeProcessProtocolSP process_sp (m_thread.GetProcess ());
463     if (!process_sp)
464         return false;
465     NativeProcessLinux *const process_p = reinterpret_cast<NativeProcessLinux*> (process_sp.get ());
466 
467     return process_p->WriteGPR (m_thread.GetID (), &m_gpr_arm, GetRegisterInfoInterface ().GetGPRSize ()).Success();
468 }
469 
470 bool
471 NativeRegisterContextLinux_arm::IsFPR(unsigned reg) const
472 {
473     return (m_reg_info.first_fpr <= reg && reg <= m_reg_info.last_fpr);
474 }
475 
476 bool
477 NativeRegisterContextLinux_arm::ReadFPR ()
478 {
479     NativeProcessProtocolSP process_sp (m_thread.GetProcess ());
480     if (!process_sp)
481         return false;
482 
483     NativeProcessLinux *const process_p = reinterpret_cast<NativeProcessLinux*> (process_sp.get ());
484     return process_p->ReadFPR (m_thread.GetID (), &m_fpr, sizeof (m_fpr)).Success();
485 }
486 
487 bool
488 NativeRegisterContextLinux_arm::WriteFPR ()
489 {
490     NativeProcessProtocolSP process_sp (m_thread.GetProcess ());
491     if (!process_sp)
492         return false;
493 
494     NativeProcessLinux *const process_p = reinterpret_cast<NativeProcessLinux*> (process_sp.get ());
495     return process_p->WriteFPR (m_thread.GetID (), &m_fpr, sizeof (m_fpr)).Success();
496 }
497 
498 lldb::ByteOrder
499 NativeRegisterContextLinux_arm::GetByteOrder() const
500 {
501     // Get the target process whose privileged thread was used for the register read.
502     lldb::ByteOrder byte_order = lldb::eByteOrderInvalid;
503 
504     NativeProcessProtocolSP process_sp (m_thread.GetProcess ());
505     if (!process_sp)
506         return byte_order;
507 
508     if (!process_sp->GetByteOrder (byte_order))
509     {
510         // FIXME log here
511     }
512 
513     return byte_order;
514 }
515 
516 size_t
517 NativeRegisterContextLinux_arm::GetGPRSize() const
518 {
519     return GetRegisterInfoInterface().GetGPRSize();
520 }
521