1 //===-- NativeRegisterContextLinux_x86_64.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 #if defined(__i386__) || defined(__x86_64__)
11 
12 #include "NativeRegisterContextLinux_x86_64.h"
13 
14 #include "lldb/Core/Log.h"
15 #include "lldb/Core/DataBufferHeap.h"
16 #include "lldb/Core/Error.h"
17 #include "lldb/Core/RegisterValue.h"
18 #include "lldb/Host/HostInfo.h"
19 
20 #include "Plugins/Process/Utility/RegisterContextLinux_i386.h"
21 #include "Plugins/Process/Utility/RegisterContextLinux_x86_64.h"
22 
23 using namespace lldb_private;
24 using namespace lldb_private::process_linux;
25 
26 // ----------------------------------------------------------------------------
27 // Private namespace.
28 // ----------------------------------------------------------------------------
29 
30 namespace
31 {
32     // x86 32-bit general purpose registers.
33     const uint32_t
34     g_gpr_regnums_i386[] =
35     {
36         lldb_eax_i386,
37         lldb_ebx_i386,
38         lldb_ecx_i386,
39         lldb_edx_i386,
40         lldb_edi_i386,
41         lldb_esi_i386,
42         lldb_ebp_i386,
43         lldb_esp_i386,
44         lldb_eip_i386,
45         lldb_eflags_i386,
46         lldb_cs_i386,
47         lldb_fs_i386,
48         lldb_gs_i386,
49         lldb_ss_i386,
50         lldb_ds_i386,
51         lldb_es_i386,
52         lldb_ax_i386,
53         lldb_bx_i386,
54         lldb_cx_i386,
55         lldb_dx_i386,
56         lldb_di_i386,
57         lldb_si_i386,
58         lldb_bp_i386,
59         lldb_sp_i386,
60         lldb_ah_i386,
61         lldb_bh_i386,
62         lldb_ch_i386,
63         lldb_dh_i386,
64         lldb_al_i386,
65         lldb_bl_i386,
66         lldb_cl_i386,
67         lldb_dl_i386,
68         LLDB_INVALID_REGNUM // register sets need to end with this flag
69     };
70     static_assert((sizeof(g_gpr_regnums_i386) / sizeof(g_gpr_regnums_i386[0])) - 1 == k_num_gpr_registers_i386,
71                   "g_gpr_regnums_i386 has wrong number of register infos");
72 
73     // x86 32-bit floating point registers.
74     const uint32_t
75     g_fpu_regnums_i386[] =
76     {
77         lldb_fctrl_i386,
78         lldb_fstat_i386,
79         lldb_ftag_i386,
80         lldb_fop_i386,
81         lldb_fiseg_i386,
82         lldb_fioff_i386,
83         lldb_foseg_i386,
84         lldb_fooff_i386,
85         lldb_mxcsr_i386,
86         lldb_mxcsrmask_i386,
87         lldb_st0_i386,
88         lldb_st1_i386,
89         lldb_st2_i386,
90         lldb_st3_i386,
91         lldb_st4_i386,
92         lldb_st5_i386,
93         lldb_st6_i386,
94         lldb_st7_i386,
95         lldb_mm0_i386,
96         lldb_mm1_i386,
97         lldb_mm2_i386,
98         lldb_mm3_i386,
99         lldb_mm4_i386,
100         lldb_mm5_i386,
101         lldb_mm6_i386,
102         lldb_mm7_i386,
103         lldb_xmm0_i386,
104         lldb_xmm1_i386,
105         lldb_xmm2_i386,
106         lldb_xmm3_i386,
107         lldb_xmm4_i386,
108         lldb_xmm5_i386,
109         lldb_xmm6_i386,
110         lldb_xmm7_i386,
111         LLDB_INVALID_REGNUM // register sets need to end with this flag
112     };
113     static_assert((sizeof(g_fpu_regnums_i386) / sizeof(g_fpu_regnums_i386[0])) - 1 == k_num_fpr_registers_i386,
114                   "g_fpu_regnums_i386 has wrong number of register infos");
115 
116     // x86 32-bit AVX registers.
117     const uint32_t
118     g_avx_regnums_i386[] =
119     {
120         lldb_ymm0_i386,
121         lldb_ymm1_i386,
122         lldb_ymm2_i386,
123         lldb_ymm3_i386,
124         lldb_ymm4_i386,
125         lldb_ymm5_i386,
126         lldb_ymm6_i386,
127         lldb_ymm7_i386,
128         LLDB_INVALID_REGNUM // register sets need to end with this flag
129     };
130     static_assert((sizeof(g_avx_regnums_i386) / sizeof(g_avx_regnums_i386[0])) - 1 == k_num_avx_registers_i386,
131                   " g_avx_regnums_i386 has wrong number of register infos");
132 
133     // x86 64-bit general purpose registers.
134     static const
135     uint32_t g_gpr_regnums_x86_64[] =
136     {
137         lldb_rax_x86_64,
138         lldb_rbx_x86_64,
139         lldb_rcx_x86_64,
140         lldb_rdx_x86_64,
141         lldb_rdi_x86_64,
142         lldb_rsi_x86_64,
143         lldb_rbp_x86_64,
144         lldb_rsp_x86_64,
145         lldb_r8_x86_64,
146         lldb_r9_x86_64,
147         lldb_r10_x86_64,
148         lldb_r11_x86_64,
149         lldb_r12_x86_64,
150         lldb_r13_x86_64,
151         lldb_r14_x86_64,
152         lldb_r15_x86_64,
153         lldb_rip_x86_64,
154         lldb_rflags_x86_64,
155         lldb_cs_x86_64,
156         lldb_fs_x86_64,
157         lldb_gs_x86_64,
158         lldb_ss_x86_64,
159         lldb_ds_x86_64,
160         lldb_es_x86_64,
161         lldb_eax_x86_64,
162         lldb_ebx_x86_64,
163         lldb_ecx_x86_64,
164         lldb_edx_x86_64,
165         lldb_edi_x86_64,
166         lldb_esi_x86_64,
167         lldb_ebp_x86_64,
168         lldb_esp_x86_64,
169         lldb_r8d_x86_64,    // Low 32 bits or r8
170         lldb_r9d_x86_64,    // Low 32 bits or r9
171         lldb_r10d_x86_64,   // Low 32 bits or r10
172         lldb_r11d_x86_64,   // Low 32 bits or r11
173         lldb_r12d_x86_64,   // Low 32 bits or r12
174         lldb_r13d_x86_64,   // Low 32 bits or r13
175         lldb_r14d_x86_64,   // Low 32 bits or r14
176         lldb_r15d_x86_64,   // Low 32 bits or r15
177         lldb_ax_x86_64,
178         lldb_bx_x86_64,
179         lldb_cx_x86_64,
180         lldb_dx_x86_64,
181         lldb_di_x86_64,
182         lldb_si_x86_64,
183         lldb_bp_x86_64,
184         lldb_sp_x86_64,
185         lldb_r8w_x86_64,    // Low 16 bits or r8
186         lldb_r9w_x86_64,    // Low 16 bits or r9
187         lldb_r10w_x86_64,   // Low 16 bits or r10
188         lldb_r11w_x86_64,   // Low 16 bits or r11
189         lldb_r12w_x86_64,   // Low 16 bits or r12
190         lldb_r13w_x86_64,   // Low 16 bits or r13
191         lldb_r14w_x86_64,   // Low 16 bits or r14
192         lldb_r15w_x86_64,   // Low 16 bits or r15
193         lldb_ah_x86_64,
194         lldb_bh_x86_64,
195         lldb_ch_x86_64,
196         lldb_dh_x86_64,
197         lldb_al_x86_64,
198         lldb_bl_x86_64,
199         lldb_cl_x86_64,
200         lldb_dl_x86_64,
201         lldb_dil_x86_64,
202         lldb_sil_x86_64,
203         lldb_bpl_x86_64,
204         lldb_spl_x86_64,
205         lldb_r8l_x86_64,    // Low 8 bits or r8
206         lldb_r9l_x86_64,    // Low 8 bits or r9
207         lldb_r10l_x86_64,   // Low 8 bits or r10
208         lldb_r11l_x86_64,   // Low 8 bits or r11
209         lldb_r12l_x86_64,   // Low 8 bits or r12
210         lldb_r13l_x86_64,   // Low 8 bits or r13
211         lldb_r14l_x86_64,   // Low 8 bits or r14
212         lldb_r15l_x86_64,   // Low 8 bits or r15
213         LLDB_INVALID_REGNUM // register sets need to end with this flag
214     };
215     static_assert((sizeof(g_gpr_regnums_x86_64) / sizeof(g_gpr_regnums_x86_64[0])) - 1 == k_num_gpr_registers_x86_64,
216                   "g_gpr_regnums_x86_64 has wrong number of register infos");
217 
218     // x86 64-bit floating point registers.
219     static const uint32_t
220     g_fpu_regnums_x86_64[] =
221     {
222         lldb_fctrl_x86_64,
223         lldb_fstat_x86_64,
224         lldb_ftag_x86_64,
225         lldb_fop_x86_64,
226         lldb_fiseg_x86_64,
227         lldb_fioff_x86_64,
228         lldb_foseg_x86_64,
229         lldb_fooff_x86_64,
230         lldb_mxcsr_x86_64,
231         lldb_mxcsrmask_x86_64,
232         lldb_st0_x86_64,
233         lldb_st1_x86_64,
234         lldb_st2_x86_64,
235         lldb_st3_x86_64,
236         lldb_st4_x86_64,
237         lldb_st5_x86_64,
238         lldb_st6_x86_64,
239         lldb_st7_x86_64,
240         lldb_mm0_x86_64,
241         lldb_mm1_x86_64,
242         lldb_mm2_x86_64,
243         lldb_mm3_x86_64,
244         lldb_mm4_x86_64,
245         lldb_mm5_x86_64,
246         lldb_mm6_x86_64,
247         lldb_mm7_x86_64,
248         lldb_xmm0_x86_64,
249         lldb_xmm1_x86_64,
250         lldb_xmm2_x86_64,
251         lldb_xmm3_x86_64,
252         lldb_xmm4_x86_64,
253         lldb_xmm5_x86_64,
254         lldb_xmm6_x86_64,
255         lldb_xmm7_x86_64,
256         lldb_xmm8_x86_64,
257         lldb_xmm9_x86_64,
258         lldb_xmm10_x86_64,
259         lldb_xmm11_x86_64,
260         lldb_xmm12_x86_64,
261         lldb_xmm13_x86_64,
262         lldb_xmm14_x86_64,
263         lldb_xmm15_x86_64,
264         LLDB_INVALID_REGNUM // register sets need to end with this flag
265     };
266     static_assert((sizeof(g_fpu_regnums_x86_64) / sizeof(g_fpu_regnums_x86_64[0])) - 1 == k_num_fpr_registers_x86_64,
267                   "g_fpu_regnums_x86_64 has wrong number of register infos");
268 
269     // x86 64-bit AVX registers.
270     static const uint32_t
271     g_avx_regnums_x86_64[] =
272     {
273         lldb_ymm0_x86_64,
274         lldb_ymm1_x86_64,
275         lldb_ymm2_x86_64,
276         lldb_ymm3_x86_64,
277         lldb_ymm4_x86_64,
278         lldb_ymm5_x86_64,
279         lldb_ymm6_x86_64,
280         lldb_ymm7_x86_64,
281         lldb_ymm8_x86_64,
282         lldb_ymm9_x86_64,
283         lldb_ymm10_x86_64,
284         lldb_ymm11_x86_64,
285         lldb_ymm12_x86_64,
286         lldb_ymm13_x86_64,
287         lldb_ymm14_x86_64,
288         lldb_ymm15_x86_64,
289         LLDB_INVALID_REGNUM // register sets need to end with this flag
290     };
291     static_assert((sizeof(g_avx_regnums_x86_64) / sizeof(g_avx_regnums_x86_64[0])) - 1 == k_num_avx_registers_x86_64,
292                   "g_avx_regnums_x86_64 has wrong number of register infos");
293 
294     // Number of register sets provided by this context.
295     enum
296     {
297         k_num_extended_register_sets = 1,
298         k_num_register_sets = 3
299     };
300 
301     // Register sets for x86 32-bit.
302     static const RegisterSet
303     g_reg_sets_i386[k_num_register_sets] =
304     {
305         { "General Purpose Registers",  "gpr", k_num_gpr_registers_i386, g_gpr_regnums_i386 },
306         { "Floating Point Registers",   "fpu", k_num_fpr_registers_i386, g_fpu_regnums_i386 },
307         { "Advanced Vector Extensions", "avx", k_num_avx_registers_i386, g_avx_regnums_i386 }
308     };
309 
310     // Register sets for x86 64-bit.
311     static const RegisterSet
312     g_reg_sets_x86_64[k_num_register_sets] =
313     {
314         { "General Purpose Registers",  "gpr", k_num_gpr_registers_x86_64, g_gpr_regnums_x86_64 },
315         { "Floating Point Registers",   "fpu", k_num_fpr_registers_x86_64, g_fpu_regnums_x86_64 },
316         { "Advanced Vector Extensions", "avx", k_num_avx_registers_x86_64, g_avx_regnums_x86_64 }
317     };
318 }
319 
320 #define REG_CONTEXT_SIZE (GetRegisterInfoInterface ().GetGPRSize () + sizeof(FPR))
321 
322 // ----------------------------------------------------------------------------
323 // Required ptrace defines.
324 // ----------------------------------------------------------------------------
325 
326 // Support ptrace extensions even when compiled without required kernel support
327 #ifndef NT_X86_XSTATE
328 #define NT_X86_XSTATE 0x202
329 #endif
330 
331 NativeRegisterContextLinux*
332 NativeRegisterContextLinux::CreateHostNativeRegisterContextLinux(const ArchSpec& target_arch,
333                                                                  NativeThreadProtocol &native_thread,
334                                                                  uint32_t concrete_frame_idx)
335 {
336     return new NativeRegisterContextLinux_x86_64(target_arch, native_thread, concrete_frame_idx);
337 }
338 
339 // ----------------------------------------------------------------------------
340 // NativeRegisterContextLinux_x86_64 members.
341 // ----------------------------------------------------------------------------
342 
343 static RegisterInfoInterface*
344 CreateRegisterInfoInterface(const ArchSpec& target_arch)
345 {
346     if (HostInfo::GetArchitecture().GetAddressByteSize() == 4)
347     {
348         // 32-bit hosts run with a RegisterContextLinux_i386 context.
349         return new RegisterContextLinux_i386(target_arch);
350     }
351     else
352     {
353         assert((HostInfo::GetArchitecture().GetAddressByteSize() == 8) &&
354                "Register setting path assumes this is a 64-bit host");
355         // X86_64 hosts know how to work with 64-bit and 32-bit EXEs using the x86_64 register context.
356         return new RegisterContextLinux_x86_64 (target_arch);
357     }
358 }
359 
360 NativeRegisterContextLinux_x86_64::NativeRegisterContextLinux_x86_64 (const ArchSpec& target_arch,
361                                                                       NativeThreadProtocol &native_thread,
362                                                                       uint32_t concrete_frame_idx) :
363     NativeRegisterContextLinux (native_thread, concrete_frame_idx, CreateRegisterInfoInterface(target_arch)),
364     m_fpr_type (eFPRTypeNotValid),
365     m_fpr (),
366     m_iovec (),
367     m_ymm_set (),
368     m_reg_info (),
369     m_gpr_x86_64 ()
370 {
371     // Set up data about ranges of valid registers.
372     switch (target_arch.GetMachine ())
373     {
374         case llvm::Triple::x86:
375             m_reg_info.num_registers        = k_num_registers_i386;
376             m_reg_info.num_gpr_registers    = k_num_gpr_registers_i386;
377             m_reg_info.num_fpr_registers    = k_num_fpr_registers_i386;
378             m_reg_info.num_avx_registers    = k_num_avx_registers_i386;
379             m_reg_info.last_gpr             = k_last_gpr_i386;
380             m_reg_info.first_fpr            = k_first_fpr_i386;
381             m_reg_info.last_fpr             = k_last_fpr_i386;
382             m_reg_info.first_st             = lldb_st0_i386;
383             m_reg_info.last_st              = lldb_st7_i386;
384             m_reg_info.first_mm             = lldb_mm0_i386;
385             m_reg_info.last_mm              = lldb_mm7_i386;
386             m_reg_info.first_xmm            = lldb_xmm0_i386;
387             m_reg_info.last_xmm             = lldb_xmm7_i386;
388             m_reg_info.first_ymm            = lldb_ymm0_i386;
389             m_reg_info.last_ymm             = lldb_ymm7_i386;
390             m_reg_info.first_dr             = lldb_dr0_i386;
391             m_reg_info.gpr_flags            = lldb_eflags_i386;
392             break;
393         case llvm::Triple::x86_64:
394             m_reg_info.num_registers        = k_num_registers_x86_64;
395             m_reg_info.num_gpr_registers    = k_num_gpr_registers_x86_64;
396             m_reg_info.num_fpr_registers    = k_num_fpr_registers_x86_64;
397             m_reg_info.num_avx_registers    = k_num_avx_registers_x86_64;
398             m_reg_info.last_gpr             = k_last_gpr_x86_64;
399             m_reg_info.first_fpr            = k_first_fpr_x86_64;
400             m_reg_info.last_fpr             = k_last_fpr_x86_64;
401             m_reg_info.first_st             = lldb_st0_x86_64;
402             m_reg_info.last_st              = lldb_st7_x86_64;
403             m_reg_info.first_mm             = lldb_mm0_x86_64;
404             m_reg_info.last_mm              = lldb_mm7_x86_64;
405             m_reg_info.first_xmm            = lldb_xmm0_x86_64;
406             m_reg_info.last_xmm             = lldb_xmm15_x86_64;
407             m_reg_info.first_ymm            = lldb_ymm0_x86_64;
408             m_reg_info.last_ymm             = lldb_ymm15_x86_64;
409             m_reg_info.first_dr             = lldb_dr0_x86_64;
410             m_reg_info.gpr_flags            = lldb_rflags_x86_64;
411             break;
412         default:
413             assert(false && "Unhandled target architecture.");
414             break;
415     }
416 
417     // Initialize m_iovec to point to the buffer and buffer size
418     // using the conventions of Berkeley style UIO structures, as required
419     // by PTRACE extensions.
420     m_iovec.iov_base = &m_fpr.xstate.xsave;
421     m_iovec.iov_len = sizeof(m_fpr.xstate.xsave);
422 
423     // Clear out the FPR state.
424     ::memset(&m_fpr, 0, sizeof(FPR));
425 
426     // Store byte offset of fctrl (i.e. first register of FPR)
427     const RegisterInfo *reg_info_fctrl = GetRegisterInfoByName("fctrl");
428     m_fctrl_offset_in_userarea = reg_info_fctrl->byte_offset;
429 }
430 
431 // CONSIDER after local and llgs debugging are merged, register set support can
432 // be moved into a base x86-64 class with IsRegisterSetAvailable made virtual.
433 uint32_t
434 NativeRegisterContextLinux_x86_64::GetRegisterSetCount () const
435 {
436     uint32_t sets = 0;
437     for (uint32_t set_index = 0; set_index < k_num_register_sets; ++set_index)
438     {
439         if (IsRegisterSetAvailable (set_index))
440             ++sets;
441     }
442 
443     return sets;
444 }
445 
446 uint32_t
447 NativeRegisterContextLinux_x86_64::GetUserRegisterCount() const
448 {
449     uint32_t count = 0;
450     for (uint32_t set_index = 0; set_index < k_num_register_sets; ++set_index)
451     {
452         const RegisterSet* set = GetRegisterSet(set_index);
453         if (set)
454             count += set->num_registers;
455     }
456     return count;
457 }
458 
459 const RegisterSet *
460 NativeRegisterContextLinux_x86_64::GetRegisterSet (uint32_t set_index) const
461 {
462     if (!IsRegisterSetAvailable (set_index))
463         return nullptr;
464 
465     switch (GetRegisterInfoInterface ().GetTargetArchitecture ().GetMachine ())
466     {
467         case llvm::Triple::x86:
468             return &g_reg_sets_i386[set_index];
469         case llvm::Triple::x86_64:
470             return &g_reg_sets_x86_64[set_index];
471         default:
472             assert (false && "Unhandled target architecture.");
473             return nullptr;
474     }
475 
476     return nullptr;
477 }
478 
479 Error
480 NativeRegisterContextLinux_x86_64::ReadRegister (const RegisterInfo *reg_info, RegisterValue &reg_value)
481 {
482     Error error;
483 
484     if (!reg_info)
485     {
486         error.SetErrorString ("reg_info NULL");
487         return error;
488     }
489 
490     const uint32_t reg = reg_info->kinds[lldb::eRegisterKindLLDB];
491     if (reg == LLDB_INVALID_REGNUM)
492     {
493         // This is likely an internal register for lldb use only and should not be directly queried.
494         error.SetErrorStringWithFormat ("register \"%s\" is an internal-only lldb register, cannot read directly", reg_info->name);
495         return error;
496     }
497 
498     if (IsFPR(reg, GetFPRType()))
499     {
500         error = ReadFPR();
501         if (error.Fail())
502             return error;
503     }
504     else
505     {
506         uint32_t full_reg = reg;
507         bool is_subreg = reg_info->invalidate_regs && (reg_info->invalidate_regs[0] != LLDB_INVALID_REGNUM);
508 
509         if (is_subreg)
510         {
511             // Read the full aligned 64-bit register.
512             full_reg = reg_info->invalidate_regs[0];
513         }
514 
515         error = ReadRegisterRaw(full_reg, reg_value);
516 
517         if (error.Success ())
518         {
519             // If our read was not aligned (for ah,bh,ch,dh), shift our returned value one byte to the right.
520             if (is_subreg && (reg_info->byte_offset & 0x1))
521                 reg_value.SetUInt64(reg_value.GetAsUInt64() >> 8);
522 
523             // If our return byte size was greater than the return value reg size, then
524             // use the type specified by reg_info rather than the uint64_t default
525             if (reg_value.GetByteSize() > reg_info->byte_size)
526                 reg_value.SetType(reg_info);
527         }
528         return error;
529     }
530 
531     if (reg_info->encoding == lldb::eEncodingVector)
532     {
533         lldb::ByteOrder byte_order = GetByteOrder();
534 
535         if (byte_order != lldb::eByteOrderInvalid)
536         {
537             if (reg >= m_reg_info.first_st && reg <= m_reg_info.last_st)
538                 reg_value.SetBytes(m_fpr.xstate.fxsave.stmm[reg - m_reg_info.first_st].bytes, reg_info->byte_size, byte_order);
539             if (reg >= m_reg_info.first_mm && reg <= m_reg_info.last_mm)
540                 reg_value.SetBytes(m_fpr.xstate.fxsave.stmm[reg - m_reg_info.first_mm].bytes, reg_info->byte_size, byte_order);
541             if (reg >= m_reg_info.first_xmm && reg <= m_reg_info.last_xmm)
542                 reg_value.SetBytes(m_fpr.xstate.fxsave.xmm[reg - m_reg_info.first_xmm].bytes, reg_info->byte_size, byte_order);
543             if (reg >= m_reg_info.first_ymm && reg <= m_reg_info.last_ymm)
544             {
545                 // Concatenate ymm using the register halves in xmm.bytes and ymmh.bytes
546                 if (GetFPRType() == eFPRTypeXSAVE && CopyXSTATEtoYMM(reg, byte_order))
547                     reg_value.SetBytes(m_ymm_set.ymm[reg - m_reg_info.first_ymm].bytes, reg_info->byte_size, byte_order);
548                 else
549                 {
550                     error.SetErrorString ("failed to copy ymm register value");
551                     return error;
552                 }
553             }
554 
555             if (reg_value.GetType() != RegisterValue::eTypeBytes)
556                 error.SetErrorString ("write failed - type was expected to be RegisterValue::eTypeBytes");
557 
558             return error;
559         }
560 
561         error.SetErrorString ("byte order is invalid");
562         return error;
563     }
564 
565     // Get pointer to m_fpr.xstate.fxsave variable and set the data from it.
566 
567     // Byte offsets of all registers are calculated wrt 'UserArea' structure.
568     // However, ReadFPR() reads fpu registers {using ptrace(PTRACE_GETFPREGS,..)}
569     // and stores them in 'm_fpr' (of type FPR structure). To extract values of fpu
570     // registers, m_fpr should be read at byte offsets calculated wrt to FPR structure.
571 
572     // Since, FPR structure is also one of the member of UserArea structure.
573     // byte_offset(fpu wrt FPR) = byte_offset(fpu wrt UserArea) - byte_offset(fctrl wrt UserArea)
574     assert ( (reg_info->byte_offset - m_fctrl_offset_in_userarea) < sizeof(m_fpr));
575     uint8_t *src = (uint8_t *)&m_fpr + reg_info->byte_offset - m_fctrl_offset_in_userarea;
576     switch (reg_info->byte_size)
577     {
578         case 1:
579             reg_value.SetUInt8(*(uint8_t *)src);
580             break;
581         case 2:
582             reg_value.SetUInt16(*(uint16_t *)src);
583             break;
584         case 4:
585             reg_value.SetUInt32(*(uint32_t *)src);
586             break;
587         case 8:
588             reg_value.SetUInt64(*(uint64_t *)src);
589             break;
590         default:
591             assert(false && "Unhandled data size.");
592             error.SetErrorStringWithFormat ("unhandled byte size: %" PRIu32, reg_info->byte_size);
593             break;
594     }
595 
596     return error;
597 }
598 
599 Error
600 NativeRegisterContextLinux_x86_64::WriteRegister (const RegisterInfo *reg_info, const RegisterValue &reg_value)
601 {
602     assert (reg_info && "reg_info is null");
603 
604     const uint32_t reg_index = reg_info->kinds[lldb::eRegisterKindLLDB];
605     if (reg_index == LLDB_INVALID_REGNUM)
606         return Error ("no lldb regnum for %s", reg_info && reg_info->name ? reg_info->name : "<unknown register>");
607 
608     if (IsGPR(reg_index))
609         return WriteRegisterRaw(reg_index, reg_value);
610 
611     if (IsFPR(reg_index, GetFPRType()))
612     {
613         if (reg_info->encoding == lldb::eEncodingVector)
614         {
615             if (reg_index >= m_reg_info.first_st && reg_index <= m_reg_info.last_st)
616                 ::memcpy (m_fpr.xstate.fxsave.stmm[reg_index - m_reg_info.first_st].bytes, reg_value.GetBytes(), reg_value.GetByteSize());
617 
618             if (reg_index >= m_reg_info.first_mm && reg_index <= m_reg_info.last_mm)
619                 ::memcpy (m_fpr.xstate.fxsave.stmm[reg_index - m_reg_info.first_mm].bytes, reg_value.GetBytes(), reg_value.GetByteSize());
620 
621             if (reg_index >= m_reg_info.first_xmm && reg_index <= m_reg_info.last_xmm)
622                 ::memcpy (m_fpr.xstate.fxsave.xmm[reg_index - m_reg_info.first_xmm].bytes, reg_value.GetBytes(), reg_value.GetByteSize());
623 
624             if (reg_index >= m_reg_info.first_ymm && reg_index <= m_reg_info.last_ymm)
625             {
626                 if (GetFPRType() != eFPRTypeXSAVE)
627                     return Error ("target processor does not support AVX");
628 
629                 // Store ymm register content, and split into the register halves in xmm.bytes and ymmh.bytes
630                 ::memcpy (m_ymm_set.ymm[reg_index - m_reg_info.first_ymm].bytes, reg_value.GetBytes(), reg_value.GetByteSize());
631                 if (!CopyYMMtoXSTATE(reg_index, GetByteOrder()))
632                     return Error ("CopyYMMtoXSTATE() failed");
633             }
634         }
635         else
636         {
637             // Get pointer to m_fpr.xstate.fxsave variable and set the data to it.
638 
639             // Byte offsets of all registers are calculated wrt 'UserArea' structure.
640             // However, WriteFPR() takes m_fpr (of type FPR structure) and writes only fpu
641             // registers using ptrace(PTRACE_SETFPREGS,..) API. Hence fpu registers should
642             // be written in m_fpr at byte offsets calculated wrt FPR structure.
643 
644             // Since, FPR structure is also one of the member of UserArea structure.
645             // byte_offset(fpu wrt FPR) = byte_offset(fpu wrt UserArea) - byte_offset(fctrl wrt UserArea)
646             assert ( (reg_info->byte_offset - m_fctrl_offset_in_userarea) < sizeof(m_fpr));
647             uint8_t *dst = (uint8_t *)&m_fpr + reg_info->byte_offset - m_fctrl_offset_in_userarea;
648             switch (reg_info->byte_size)
649             {
650                 case 1:
651                     *(uint8_t *)dst = reg_value.GetAsUInt8();
652                     break;
653                 case 2:
654                     *(uint16_t *)dst = reg_value.GetAsUInt16();
655                     break;
656                 case 4:
657                     *(uint32_t *)dst = reg_value.GetAsUInt32();
658                     break;
659                 case 8:
660                     *(uint64_t *)dst = reg_value.GetAsUInt64();
661                     break;
662                 default:
663                     assert(false && "Unhandled data size.");
664                     return Error ("unhandled register data size %" PRIu32, reg_info->byte_size);
665             }
666         }
667 
668         Error error = WriteFPR();
669         if (error.Fail())
670             return error;
671 
672         if (IsAVX(reg_index))
673         {
674             if (!CopyYMMtoXSTATE(reg_index, GetByteOrder()))
675                 return Error ("CopyYMMtoXSTATE() failed");
676         }
677         return Error ();
678     }
679     return Error ("failed - register wasn't recognized to be a GPR or an FPR, write strategy unknown");
680 }
681 
682 Error
683 NativeRegisterContextLinux_x86_64::ReadAllRegisterValues (lldb::DataBufferSP &data_sp)
684 {
685     Error error;
686 
687     data_sp.reset (new DataBufferHeap (REG_CONTEXT_SIZE, 0));
688     if (!data_sp)
689     {
690         error.SetErrorStringWithFormat ("failed to allocate DataBufferHeap instance of size %" PRIu64, REG_CONTEXT_SIZE);
691         return error;
692     }
693 
694     error = ReadGPR();
695     if (error.Fail())
696         return error;
697 
698     error = ReadFPR();
699     if (error.Fail())
700         return error;
701 
702     uint8_t *dst = data_sp->GetBytes ();
703     if (dst == nullptr)
704     {
705         error.SetErrorStringWithFormat ("DataBufferHeap instance of size %" PRIu64 " returned a null pointer", REG_CONTEXT_SIZE);
706         return error;
707     }
708 
709     ::memcpy (dst, &m_gpr_x86_64, GetRegisterInfoInterface ().GetGPRSize ());
710     dst += GetRegisterInfoInterface ().GetGPRSize ();
711     if (GetFPRType () == eFPRTypeFXSAVE)
712         ::memcpy (dst, &m_fpr.xstate.fxsave, sizeof(m_fpr.xstate.fxsave));
713     else if (GetFPRType () == eFPRTypeXSAVE)
714     {
715         lldb::ByteOrder byte_order = GetByteOrder ();
716 
717         // Assemble the YMM register content from the register halves.
718         for (uint32_t reg = m_reg_info.first_ymm; reg <= m_reg_info.last_ymm; ++reg)
719         {
720             if (!CopyXSTATEtoYMM (reg, byte_order))
721             {
722                 error.SetErrorStringWithFormat ("NativeRegisterContextLinux_x86_64::%s CopyXSTATEtoYMM() failed for reg num %" PRIu32, __FUNCTION__, reg);
723                 return error;
724             }
725         }
726 
727         // Copy the extended register state including the assembled ymm registers.
728         ::memcpy (dst, &m_fpr, sizeof (m_fpr));
729     }
730     else
731     {
732         assert (false && "how do we save the floating point registers?");
733         error.SetErrorString ("unsure how to save the floating point registers");
734     }
735     /** The following code is specific to Linux x86 based architectures,
736      *  where the register orig_eax (32 bit)/orig_rax (64 bit) is set to
737      *  -1 to solve the bug 23659, such a setting prevents the automatic
738      *  decrement of the instruction pointer which was causing the SIGILL
739      *  exception.
740      * **/
741 
742     RegisterValue value((uint64_t) -1);
743     const RegisterInfo *reg_info = GetRegisterInfoInterface().GetDynamicRegisterInfo("orig_eax");
744     if (reg_info == nullptr)
745         reg_info = GetRegisterInfoInterface().GetDynamicRegisterInfo("orig_rax");
746 
747     if (reg_info != nullptr)
748         return DoWriteRegisterValue(reg_info->byte_offset,reg_info->name,value);
749 
750     return error;
751 }
752 
753 Error
754 NativeRegisterContextLinux_x86_64::WriteAllRegisterValues (const lldb::DataBufferSP &data_sp)
755 {
756     Error error;
757 
758     if (!data_sp)
759     {
760         error.SetErrorStringWithFormat ("NativeRegisterContextLinux_x86_64::%s invalid data_sp provided", __FUNCTION__);
761         return error;
762     }
763 
764     if (data_sp->GetByteSize () != REG_CONTEXT_SIZE)
765     {
766         error.SetErrorStringWithFormat ("NativeRegisterContextLinux_x86_64::%s data_sp contained mismatched data size, expected %" PRIu64 ", actual %" PRIu64, __FUNCTION__, REG_CONTEXT_SIZE, data_sp->GetByteSize ());
767         return error;
768     }
769 
770 
771     uint8_t *src = data_sp->GetBytes ();
772     if (src == nullptr)
773     {
774         error.SetErrorStringWithFormat ("NativeRegisterContextLinux_x86_64::%s DataBuffer::GetBytes() returned a null pointer", __FUNCTION__);
775         return error;
776     }
777     ::memcpy (&m_gpr_x86_64, src, GetRegisterInfoInterface ().GetGPRSize ());
778 
779     error = WriteGPR();
780     if (error.Fail())
781         return error;
782 
783     src += GetRegisterInfoInterface ().GetGPRSize ();
784     if (GetFPRType () == eFPRTypeFXSAVE)
785         ::memcpy (&m_fpr.xstate.fxsave, src, sizeof(m_fpr.xstate.fxsave));
786     else if (GetFPRType () == eFPRTypeXSAVE)
787         ::memcpy (&m_fpr.xstate.xsave, src, sizeof(m_fpr.xstate.xsave));
788 
789     error = WriteFPR();
790     if (error.Fail())
791         return error;
792 
793     if (GetFPRType() == eFPRTypeXSAVE)
794     {
795         lldb::ByteOrder byte_order = GetByteOrder();
796 
797         // Parse the YMM register content from the register halves.
798         for (uint32_t reg = m_reg_info.first_ymm; reg <= m_reg_info.last_ymm; ++reg)
799         {
800             if (!CopyYMMtoXSTATE (reg, byte_order))
801             {
802                 error.SetErrorStringWithFormat ("NativeRegisterContextLinux_x86_64::%s CopyYMMtoXSTATE() failed for reg num %" PRIu32, __FUNCTION__, reg);
803                 return error;
804             }
805         }
806     }
807 
808     return error;
809 }
810 
811 bool
812 NativeRegisterContextLinux_x86_64::IsRegisterSetAvailable (uint32_t set_index) const
813 {
814     // Note: Extended register sets are assumed to be at the end of g_reg_sets.
815     uint32_t num_sets = k_num_register_sets - k_num_extended_register_sets;
816 
817     if (GetFPRType () == eFPRTypeXSAVE)
818     {
819         // AVX is the first extended register set.
820         ++num_sets;
821     }
822     return (set_index < num_sets);
823 }
824 
825 bool
826 NativeRegisterContextLinux_x86_64::IsGPR(uint32_t reg_index) const
827 {
828     // GPRs come first.
829     return reg_index <= m_reg_info.last_gpr;
830 }
831 
832 NativeRegisterContextLinux_x86_64::FPRType
833 NativeRegisterContextLinux_x86_64::GetFPRType () const
834 {
835     if (m_fpr_type == eFPRTypeNotValid)
836     {
837         // TODO: Use assembly to call cpuid on the inferior and query ebx or ecx.
838 
839         // Try and see if AVX register retrieval works.
840         m_fpr_type = eFPRTypeXSAVE;
841         if (const_cast<NativeRegisterContextLinux_x86_64*>(this)->ReadFPR().Fail())
842         {
843             // Fall back to general floating point with no AVX support.
844             m_fpr_type = eFPRTypeFXSAVE;
845         }
846     }
847 
848     return m_fpr_type;
849 }
850 
851 bool
852 NativeRegisterContextLinux_x86_64::IsFPR(uint32_t reg_index) const
853 {
854     return (m_reg_info.first_fpr <= reg_index && reg_index <= m_reg_info.last_fpr);
855 }
856 
857 bool
858 NativeRegisterContextLinux_x86_64::IsFPR(uint32_t reg_index, FPRType fpr_type) const
859 {
860     bool generic_fpr = IsFPR(reg_index);
861 
862     if (fpr_type == eFPRTypeXSAVE)
863         return generic_fpr || IsAVX(reg_index);
864     return generic_fpr;
865 }
866 
867 Error
868 NativeRegisterContextLinux_x86_64::WriteFPR()
869 {
870     const FPRType fpr_type = GetFPRType ();
871     switch (fpr_type)
872     {
873     case FPRType::eFPRTypeFXSAVE:
874         return NativeRegisterContextLinux::WriteFPR();
875     case FPRType::eFPRTypeXSAVE:
876         return WriteRegisterSet(&m_iovec, sizeof(m_fpr.xstate.xsave), NT_X86_XSTATE);
877     default:
878         return Error("Unrecognized FPR type");
879     }
880 }
881 
882 bool
883 NativeRegisterContextLinux_x86_64::IsAVX(uint32_t reg_index) const
884 {
885     return (m_reg_info.first_ymm <= reg_index && reg_index <= m_reg_info.last_ymm);
886 }
887 
888 bool
889 NativeRegisterContextLinux_x86_64::CopyXSTATEtoYMM (uint32_t reg_index, lldb::ByteOrder byte_order)
890 {
891     if (!IsAVX (reg_index))
892         return false;
893 
894     if (byte_order == lldb::eByteOrderLittle)
895     {
896         ::memcpy (m_ymm_set.ymm[reg_index - m_reg_info.first_ymm].bytes,
897                  m_fpr.xstate.fxsave.xmm[reg_index - m_reg_info.first_ymm].bytes,
898                  sizeof (XMMReg));
899         ::memcpy (m_ymm_set.ymm[reg_index - m_reg_info.first_ymm].bytes + sizeof (XMMReg),
900                  m_fpr.xstate.xsave.ymmh[reg_index - m_reg_info.first_ymm].bytes,
901                  sizeof (YMMHReg));
902         return true;
903     }
904 
905     if (byte_order == lldb::eByteOrderBig)
906     {
907         ::memcpy(m_ymm_set.ymm[reg_index - m_reg_info.first_ymm].bytes + sizeof (XMMReg),
908                  m_fpr.xstate.fxsave.xmm[reg_index - m_reg_info.first_ymm].bytes,
909                  sizeof (XMMReg));
910         ::memcpy(m_ymm_set.ymm[reg_index - m_reg_info.first_ymm].bytes,
911                  m_fpr.xstate.xsave.ymmh[reg_index - m_reg_info.first_ymm].bytes,
912                  sizeof (YMMHReg));
913         return true;
914     }
915     return false; // unsupported or invalid byte order
916 
917 }
918 
919 bool
920 NativeRegisterContextLinux_x86_64::CopyYMMtoXSTATE(uint32_t reg, lldb::ByteOrder byte_order)
921 {
922     if (!IsAVX(reg))
923         return false;
924 
925     if (byte_order == lldb::eByteOrderLittle)
926     {
927         ::memcpy(m_fpr.xstate.fxsave.xmm[reg - m_reg_info.first_ymm].bytes,
928                  m_ymm_set.ymm[reg - m_reg_info.first_ymm].bytes,
929                  sizeof(XMMReg));
930         ::memcpy(m_fpr.xstate.xsave.ymmh[reg - m_reg_info.first_ymm].bytes,
931                  m_ymm_set.ymm[reg - m_reg_info.first_ymm].bytes + sizeof(XMMReg),
932                  sizeof(YMMHReg));
933         return true;
934     }
935 
936     if (byte_order == lldb::eByteOrderBig)
937     {
938         ::memcpy(m_fpr.xstate.fxsave.xmm[reg - m_reg_info.first_ymm].bytes,
939                  m_ymm_set.ymm[reg - m_reg_info.first_ymm].bytes + sizeof(XMMReg),
940                  sizeof(XMMReg));
941         ::memcpy(m_fpr.xstate.xsave.ymmh[reg - m_reg_info.first_ymm].bytes,
942                  m_ymm_set.ymm[reg - m_reg_info.first_ymm].bytes,
943                  sizeof(YMMHReg));
944         return true;
945     }
946     return false; // unsupported or invalid byte order
947 }
948 
949 void*
950 NativeRegisterContextLinux_x86_64::GetFPRBuffer()
951 {
952     const FPRType fpr_type = GetFPRType ();
953     switch (fpr_type)
954     {
955     case FPRType::eFPRTypeFXSAVE:
956         return &m_fpr.xstate.fxsave;
957     case FPRType::eFPRTypeXSAVE:
958         return &m_iovec;
959     default:
960         return nullptr;
961     }
962 }
963 
964 size_t
965 NativeRegisterContextLinux_x86_64::GetFPRSize()
966 {
967     const FPRType fpr_type = GetFPRType ();
968     switch (fpr_type)
969     {
970     case FPRType::eFPRTypeFXSAVE:
971         return sizeof(m_fpr.xstate.fxsave);
972     case FPRType::eFPRTypeXSAVE:
973         return sizeof(m_iovec);
974     default:
975         return 0;
976     }
977 }
978 
979 Error
980 NativeRegisterContextLinux_x86_64::ReadFPR ()
981 {
982     const FPRType fpr_type = GetFPRType ();
983     switch (fpr_type)
984     {
985     case FPRType::eFPRTypeFXSAVE:
986         return NativeRegisterContextLinux::ReadFPR();
987     case FPRType::eFPRTypeXSAVE:
988         return ReadRegisterSet(&m_iovec, sizeof(m_fpr.xstate.xsave), NT_X86_XSTATE);
989     default:
990         return Error("Unrecognized FPR type");
991     }
992 }
993 
994 Error
995 NativeRegisterContextLinux_x86_64::IsWatchpointHit(uint32_t wp_index, bool &is_hit)
996 {
997     if (wp_index >= NumSupportedHardwareWatchpoints())
998         return Error("Watchpoint index out of range");
999 
1000     RegisterValue reg_value;
1001     Error error = ReadRegisterRaw(m_reg_info.first_dr + 6, reg_value);
1002     if (error.Fail())
1003     {
1004         is_hit = false;
1005         return error;
1006     }
1007 
1008     uint64_t status_bits = reg_value.GetAsUInt64();
1009 
1010     is_hit = status_bits & (1 << wp_index);
1011 
1012     return error;
1013 }
1014 
1015 Error
1016 NativeRegisterContextLinux_x86_64::GetWatchpointHitIndex(uint32_t &wp_index, lldb::addr_t trap_addr) {
1017     uint32_t num_hw_wps = NumSupportedHardwareWatchpoints();
1018     for (wp_index = 0; wp_index < num_hw_wps; ++wp_index)
1019     {
1020         bool is_hit;
1021         Error error = IsWatchpointHit(wp_index, is_hit);
1022         if (error.Fail()) {
1023             wp_index = LLDB_INVALID_INDEX32;
1024             return error;
1025         } else if (is_hit) {
1026             return error;
1027         }
1028     }
1029     wp_index = LLDB_INVALID_INDEX32;
1030     return Error();
1031 }
1032 
1033 Error
1034 NativeRegisterContextLinux_x86_64::IsWatchpointVacant(uint32_t wp_index, bool &is_vacant)
1035 {
1036     if (wp_index >= NumSupportedHardwareWatchpoints())
1037         return Error ("Watchpoint index out of range");
1038 
1039     RegisterValue reg_value;
1040     Error error = ReadRegisterRaw(m_reg_info.first_dr + 7, reg_value);
1041     if (error.Fail())
1042     {
1043         is_vacant = false;
1044         return error;
1045     }
1046 
1047     uint64_t control_bits = reg_value.GetAsUInt64();
1048 
1049     is_vacant = !(control_bits & (1 << (2 * wp_index)));
1050 
1051     return error;
1052 }
1053 
1054 Error
1055 NativeRegisterContextLinux_x86_64::SetHardwareWatchpointWithIndex(
1056         lldb::addr_t addr, size_t size, uint32_t watch_flags, uint32_t wp_index) {
1057 
1058     if (wp_index >= NumSupportedHardwareWatchpoints())
1059         return Error ("Watchpoint index out of range");
1060 
1061     // Read only watchpoints aren't supported on x86_64. Fall back to read/write waitchpoints instead.
1062     // TODO: Add logic to detect when a write happens and ignore that watchpoint hit.
1063     if (watch_flags == 0x2)
1064         watch_flags = 0x3;
1065 
1066     if (watch_flags != 0x1 && watch_flags != 0x3)
1067         return Error ("Invalid read/write bits for watchpoint");
1068 
1069     if (size != 1 && size != 2 && size != 4 && size != 8)
1070         return Error ("Invalid size for watchpoint");
1071 
1072     bool is_vacant;
1073     Error error = IsWatchpointVacant (wp_index, is_vacant);
1074     if (error.Fail()) return error;
1075     if (!is_vacant) return Error("Watchpoint index not vacant");
1076 
1077     RegisterValue reg_value;
1078     error = ReadRegisterRaw(m_reg_info.first_dr + 7, reg_value);
1079     if (error.Fail()) return error;
1080 
1081     // for watchpoints 0, 1, 2, or 3, respectively,
1082     // set bits 1, 3, 5, or 7
1083     uint64_t enable_bit = 1 << (2 * wp_index);
1084 
1085     // set bits 16-17, 20-21, 24-25, or 28-29
1086     // with 0b01 for write, and 0b11 for read/write
1087     uint64_t rw_bits = watch_flags << (16 + 4 * wp_index);
1088 
1089     // set bits 18-19, 22-23, 26-27, or 30-31
1090     // with 0b00, 0b01, 0b10, or 0b11
1091     // for 1, 2, 8 (if supported), or 4 bytes, respectively
1092     uint64_t size_bits = (size == 8 ? 0x2 : size - 1) << (18 + 4 * wp_index);
1093 
1094     uint64_t bit_mask = (0x3 << (2 * wp_index)) | (0xF << (16 + 4 * wp_index));
1095 
1096     uint64_t control_bits = reg_value.GetAsUInt64() & ~bit_mask;
1097 
1098     control_bits |= enable_bit | rw_bits | size_bits;
1099 
1100     error = WriteRegisterRaw(m_reg_info.first_dr + wp_index, RegisterValue(addr));
1101     if (error.Fail()) return error;
1102 
1103     error = WriteRegisterRaw(m_reg_info.first_dr + 7, RegisterValue(control_bits));
1104     if (error.Fail()) return error;
1105 
1106     error.Clear();
1107     return error;
1108 }
1109 
1110 bool
1111 NativeRegisterContextLinux_x86_64::ClearHardwareWatchpoint(uint32_t wp_index)
1112 {
1113     if (wp_index >= NumSupportedHardwareWatchpoints())
1114         return false;
1115 
1116     RegisterValue reg_value;
1117 
1118     // for watchpoints 0, 1, 2, or 3, respectively,
1119     // clear bits 0, 1, 2, or 3 of the debug status register (DR6)
1120     Error error = ReadRegisterRaw(m_reg_info.first_dr + 6, reg_value);
1121     if (error.Fail()) return false;
1122     uint64_t bit_mask = 1 << wp_index;
1123     uint64_t status_bits = reg_value.GetAsUInt64() & ~bit_mask;
1124     error = WriteRegisterRaw(m_reg_info.first_dr + 6, RegisterValue(status_bits));
1125     if (error.Fail()) return false;
1126 
1127     // for watchpoints 0, 1, 2, or 3, respectively,
1128     // clear bits {0-1,16-19}, {2-3,20-23}, {4-5,24-27}, or {6-7,28-31}
1129     // of the debug control register (DR7)
1130     error = ReadRegisterRaw(m_reg_info.first_dr + 7, reg_value);
1131     if (error.Fail()) return false;
1132     bit_mask = (0x3 << (2 * wp_index)) | (0xF << (16 + 4 * wp_index));
1133     uint64_t control_bits = reg_value.GetAsUInt64() & ~bit_mask;
1134     return WriteRegisterRaw(m_reg_info.first_dr + 7, RegisterValue(control_bits)).Success();
1135 }
1136 
1137 Error
1138 NativeRegisterContextLinux_x86_64::ClearAllHardwareWatchpoints()
1139 {
1140     RegisterValue reg_value;
1141 
1142     // clear bits {0-4} of the debug status register (DR6)
1143     Error error = ReadRegisterRaw(m_reg_info.first_dr + 6, reg_value);
1144     if (error.Fail()) return error;
1145     uint64_t bit_mask = 0xF;
1146     uint64_t status_bits = reg_value.GetAsUInt64() & ~bit_mask;
1147     error = WriteRegisterRaw(m_reg_info.first_dr + 6, RegisterValue(status_bits));
1148     if (error.Fail()) return error;
1149 
1150     // clear bits {0-7,16-31} of the debug control register (DR7)
1151     error = ReadRegisterRaw(m_reg_info.first_dr + 7, reg_value);
1152     if (error.Fail()) return error;
1153     bit_mask = 0xFF | (0xFFFF << 16);
1154     uint64_t control_bits = reg_value.GetAsUInt64() & ~bit_mask;
1155     return WriteRegisterRaw(m_reg_info.first_dr + 7, RegisterValue(control_bits));
1156 }
1157 
1158 uint32_t
1159 NativeRegisterContextLinux_x86_64::SetHardwareWatchpoint(
1160         lldb::addr_t addr, size_t size, uint32_t watch_flags)
1161 {
1162     Log *log(GetLogIfAllCategoriesSet(LIBLLDB_LOG_WATCHPOINTS));
1163     const uint32_t num_hw_watchpoints = NumSupportedHardwareWatchpoints();
1164     for (uint32_t wp_index = 0; wp_index < num_hw_watchpoints; ++wp_index)
1165     {
1166         bool is_vacant;
1167         Error error = IsWatchpointVacant(wp_index, is_vacant);
1168         if (is_vacant)
1169         {
1170             error = SetHardwareWatchpointWithIndex(addr, size, watch_flags, wp_index);
1171             if (error.Success())
1172                 return wp_index;
1173         }
1174         if (error.Fail() && log)
1175         {
1176             log->Printf("NativeRegisterContextLinux_x86_64::%s Error: %s",
1177                     __FUNCTION__, error.AsCString());
1178         }
1179     }
1180     return LLDB_INVALID_INDEX32;
1181 }
1182 
1183 lldb::addr_t
1184 NativeRegisterContextLinux_x86_64::GetWatchpointAddress(uint32_t wp_index)
1185 {
1186     if (wp_index >= NumSupportedHardwareWatchpoints())
1187         return LLDB_INVALID_ADDRESS;
1188     RegisterValue reg_value;
1189     if (ReadRegisterRaw(m_reg_info.first_dr + wp_index, reg_value).Fail())
1190         return LLDB_INVALID_ADDRESS;
1191     return reg_value.GetAsUInt64();
1192 }
1193 
1194 uint32_t
1195 NativeRegisterContextLinux_x86_64::NumSupportedHardwareWatchpoints ()
1196 {
1197     // Available debug address registers: dr0, dr1, dr2, dr3
1198     return 4;
1199 }
1200 
1201 #endif // defined(__i386__) || defined(__x86_64__)
1202