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/RegisterValue.h"
15 #include "lldb/Host/HostInfo.h"
16 #include "lldb/Utility/DataBufferHeap.h"
17 #include "lldb/Utility/Log.h"
18 #include "lldb/Utility/Status.h"
19 
20 #include "Plugins/Process/Utility/RegisterContextLinux_i386.h"
21 #include "Plugins/Process/Utility/RegisterContextLinux_x86_64.h"
22 
23 #include <linux/elf.h>
24 
25 using namespace lldb_private;
26 using namespace lldb_private::process_linux;
27 
28 // ----------------------------------------------------------------------------
29 // Private namespace.
30 // ----------------------------------------------------------------------------
31 
32 namespace {
33 // x86 32-bit general purpose registers.
34 const uint32_t g_gpr_regnums_i386[] = {
35     lldb_eax_i386,      lldb_ebx_i386,    lldb_ecx_i386, lldb_edx_i386,
36     lldb_edi_i386,      lldb_esi_i386,    lldb_ebp_i386, lldb_esp_i386,
37     lldb_eip_i386,      lldb_eflags_i386, lldb_cs_i386,  lldb_fs_i386,
38     lldb_gs_i386,       lldb_ss_i386,     lldb_ds_i386,  lldb_es_i386,
39     lldb_ax_i386,       lldb_bx_i386,     lldb_cx_i386,  lldb_dx_i386,
40     lldb_di_i386,       lldb_si_i386,     lldb_bp_i386,  lldb_sp_i386,
41     lldb_ah_i386,       lldb_bh_i386,     lldb_ch_i386,  lldb_dh_i386,
42     lldb_al_i386,       lldb_bl_i386,     lldb_cl_i386,  lldb_dl_i386,
43     LLDB_INVALID_REGNUM // register sets need to end with this flag
44 };
45 static_assert((sizeof(g_gpr_regnums_i386) / sizeof(g_gpr_regnums_i386[0])) -
46                       1 ==
47                   k_num_gpr_registers_i386,
48               "g_gpr_regnums_i386 has wrong number of register infos");
49 
50 // x86 32-bit floating point registers.
51 const uint32_t g_fpu_regnums_i386[] = {
52     lldb_fctrl_i386,    lldb_fstat_i386,     lldb_ftag_i386,  lldb_fop_i386,
53     lldb_fiseg_i386,    lldb_fioff_i386,     lldb_foseg_i386, lldb_fooff_i386,
54     lldb_mxcsr_i386,    lldb_mxcsrmask_i386, lldb_st0_i386,   lldb_st1_i386,
55     lldb_st2_i386,      lldb_st3_i386,       lldb_st4_i386,   lldb_st5_i386,
56     lldb_st6_i386,      lldb_st7_i386,       lldb_mm0_i386,   lldb_mm1_i386,
57     lldb_mm2_i386,      lldb_mm3_i386,       lldb_mm4_i386,   lldb_mm5_i386,
58     lldb_mm6_i386,      lldb_mm7_i386,       lldb_xmm0_i386,  lldb_xmm1_i386,
59     lldb_xmm2_i386,     lldb_xmm3_i386,      lldb_xmm4_i386,  lldb_xmm5_i386,
60     lldb_xmm6_i386,     lldb_xmm7_i386,
61     LLDB_INVALID_REGNUM // register sets need to end with this flag
62 };
63 static_assert((sizeof(g_fpu_regnums_i386) / sizeof(g_fpu_regnums_i386[0])) -
64                       1 ==
65                   k_num_fpr_registers_i386,
66               "g_fpu_regnums_i386 has wrong number of register infos");
67 
68 // x86 32-bit AVX registers.
69 const uint32_t g_avx_regnums_i386[] = {
70     lldb_ymm0_i386,     lldb_ymm1_i386, lldb_ymm2_i386, lldb_ymm3_i386,
71     lldb_ymm4_i386,     lldb_ymm5_i386, lldb_ymm6_i386, lldb_ymm7_i386,
72     LLDB_INVALID_REGNUM // register sets need to end with this flag
73 };
74 static_assert((sizeof(g_avx_regnums_i386) / sizeof(g_avx_regnums_i386[0])) -
75                       1 ==
76                   k_num_avx_registers_i386,
77               " g_avx_regnums_i386 has wrong number of register infos");
78 
79 // x64 32-bit MPX registers.
80 static const uint32_t g_mpx_regnums_i386[] = {
81     lldb_bnd0_i386,     lldb_bnd1_i386, lldb_bnd2_i386, lldb_bnd3_i386,
82     lldb_bndcfgu_i386,  lldb_bndstatus_i386,
83     LLDB_INVALID_REGNUM // register sets need to end with this flag
84 };
85 static_assert((sizeof(g_mpx_regnums_i386) / sizeof(g_mpx_regnums_i386[0])) -
86                       1 ==
87                   k_num_mpx_registers_i386,
88               "g_mpx_regnums_x86_64 has wrong number of register infos");
89 
90 // x86 64-bit general purpose registers.
91 static const uint32_t g_gpr_regnums_x86_64[] = {
92     lldb_rax_x86_64,    lldb_rbx_x86_64,    lldb_rcx_x86_64, lldb_rdx_x86_64,
93     lldb_rdi_x86_64,    lldb_rsi_x86_64,    lldb_rbp_x86_64, lldb_rsp_x86_64,
94     lldb_r8_x86_64,     lldb_r9_x86_64,     lldb_r10_x86_64, lldb_r11_x86_64,
95     lldb_r12_x86_64,    lldb_r13_x86_64,    lldb_r14_x86_64, lldb_r15_x86_64,
96     lldb_rip_x86_64,    lldb_rflags_x86_64, lldb_cs_x86_64,  lldb_fs_x86_64,
97     lldb_gs_x86_64,     lldb_ss_x86_64,     lldb_ds_x86_64,  lldb_es_x86_64,
98     lldb_eax_x86_64,    lldb_ebx_x86_64,    lldb_ecx_x86_64, lldb_edx_x86_64,
99     lldb_edi_x86_64,    lldb_esi_x86_64,    lldb_ebp_x86_64, lldb_esp_x86_64,
100     lldb_r8d_x86_64,  // Low 32 bits or r8
101     lldb_r9d_x86_64,  // Low 32 bits or r9
102     lldb_r10d_x86_64, // Low 32 bits or r10
103     lldb_r11d_x86_64, // Low 32 bits or r11
104     lldb_r12d_x86_64, // Low 32 bits or r12
105     lldb_r13d_x86_64, // Low 32 bits or r13
106     lldb_r14d_x86_64, // Low 32 bits or r14
107     lldb_r15d_x86_64, // Low 32 bits or r15
108     lldb_ax_x86_64,     lldb_bx_x86_64,     lldb_cx_x86_64,  lldb_dx_x86_64,
109     lldb_di_x86_64,     lldb_si_x86_64,     lldb_bp_x86_64,  lldb_sp_x86_64,
110     lldb_r8w_x86_64,  // Low 16 bits or r8
111     lldb_r9w_x86_64,  // Low 16 bits or r9
112     lldb_r10w_x86_64, // Low 16 bits or r10
113     lldb_r11w_x86_64, // Low 16 bits or r11
114     lldb_r12w_x86_64, // Low 16 bits or r12
115     lldb_r13w_x86_64, // Low 16 bits or r13
116     lldb_r14w_x86_64, // Low 16 bits or r14
117     lldb_r15w_x86_64, // Low 16 bits or r15
118     lldb_ah_x86_64,     lldb_bh_x86_64,     lldb_ch_x86_64,  lldb_dh_x86_64,
119     lldb_al_x86_64,     lldb_bl_x86_64,     lldb_cl_x86_64,  lldb_dl_x86_64,
120     lldb_dil_x86_64,    lldb_sil_x86_64,    lldb_bpl_x86_64, lldb_spl_x86_64,
121     lldb_r8l_x86_64,    // Low 8 bits or r8
122     lldb_r9l_x86_64,    // Low 8 bits or r9
123     lldb_r10l_x86_64,   // Low 8 bits or r10
124     lldb_r11l_x86_64,   // Low 8 bits or r11
125     lldb_r12l_x86_64,   // Low 8 bits or r12
126     lldb_r13l_x86_64,   // Low 8 bits or r13
127     lldb_r14l_x86_64,   // Low 8 bits or r14
128     lldb_r15l_x86_64,   // Low 8 bits or r15
129     LLDB_INVALID_REGNUM // register sets need to end with this flag
130 };
131 static_assert((sizeof(g_gpr_regnums_x86_64) / sizeof(g_gpr_regnums_x86_64[0])) -
132                       1 ==
133                   k_num_gpr_registers_x86_64,
134               "g_gpr_regnums_x86_64 has wrong number of register infos");
135 
136 // x86 64-bit floating point registers.
137 static const uint32_t g_fpu_regnums_x86_64[] = {
138     lldb_fctrl_x86_64,     lldb_fstat_x86_64, lldb_ftag_x86_64,
139     lldb_fop_x86_64,       lldb_fiseg_x86_64, lldb_fioff_x86_64,
140     lldb_foseg_x86_64,     lldb_fooff_x86_64, lldb_mxcsr_x86_64,
141     lldb_mxcsrmask_x86_64, lldb_st0_x86_64,   lldb_st1_x86_64,
142     lldb_st2_x86_64,       lldb_st3_x86_64,   lldb_st4_x86_64,
143     lldb_st5_x86_64,       lldb_st6_x86_64,   lldb_st7_x86_64,
144     lldb_mm0_x86_64,       lldb_mm1_x86_64,   lldb_mm2_x86_64,
145     lldb_mm3_x86_64,       lldb_mm4_x86_64,   lldb_mm5_x86_64,
146     lldb_mm6_x86_64,       lldb_mm7_x86_64,   lldb_xmm0_x86_64,
147     lldb_xmm1_x86_64,      lldb_xmm2_x86_64,  lldb_xmm3_x86_64,
148     lldb_xmm4_x86_64,      lldb_xmm5_x86_64,  lldb_xmm6_x86_64,
149     lldb_xmm7_x86_64,      lldb_xmm8_x86_64,  lldb_xmm9_x86_64,
150     lldb_xmm10_x86_64,     lldb_xmm11_x86_64, lldb_xmm12_x86_64,
151     lldb_xmm13_x86_64,     lldb_xmm14_x86_64, lldb_xmm15_x86_64,
152     LLDB_INVALID_REGNUM // register sets need to end with this flag
153 };
154 static_assert((sizeof(g_fpu_regnums_x86_64) / sizeof(g_fpu_regnums_x86_64[0])) -
155                       1 ==
156                   k_num_fpr_registers_x86_64,
157               "g_fpu_regnums_x86_64 has wrong number of register infos");
158 
159 // x86 64-bit AVX registers.
160 static const uint32_t g_avx_regnums_x86_64[] = {
161     lldb_ymm0_x86_64,   lldb_ymm1_x86_64,  lldb_ymm2_x86_64,  lldb_ymm3_x86_64,
162     lldb_ymm4_x86_64,   lldb_ymm5_x86_64,  lldb_ymm6_x86_64,  lldb_ymm7_x86_64,
163     lldb_ymm8_x86_64,   lldb_ymm9_x86_64,  lldb_ymm10_x86_64, lldb_ymm11_x86_64,
164     lldb_ymm12_x86_64,  lldb_ymm13_x86_64, lldb_ymm14_x86_64, lldb_ymm15_x86_64,
165     LLDB_INVALID_REGNUM // register sets need to end with this flag
166 };
167 static_assert((sizeof(g_avx_regnums_x86_64) / sizeof(g_avx_regnums_x86_64[0])) -
168                       1 ==
169                   k_num_avx_registers_x86_64,
170               "g_avx_regnums_x86_64 has wrong number of register infos");
171 
172 // x86 64-bit MPX registers.
173 static const uint32_t g_mpx_regnums_x86_64[] = {
174     lldb_bnd0_x86_64,    lldb_bnd1_x86_64,    lldb_bnd2_x86_64,
175     lldb_bnd3_x86_64,    lldb_bndcfgu_x86_64, lldb_bndstatus_x86_64,
176     LLDB_INVALID_REGNUM // register sets need to end with this flag
177 };
178 static_assert((sizeof(g_mpx_regnums_x86_64) / sizeof(g_mpx_regnums_x86_64[0])) -
179                       1 ==
180                   k_num_mpx_registers_x86_64,
181               "g_mpx_regnums_x86_64 has wrong number of register infos");
182 
183 // Number of register sets provided by this context.
184 enum { k_num_extended_register_sets = 2, k_num_register_sets = 4 };
185 
186 // Register sets for x86 32-bit.
187 static const RegisterSet g_reg_sets_i386[k_num_register_sets] = {
188     {"General Purpose Registers", "gpr", k_num_gpr_registers_i386,
189      g_gpr_regnums_i386},
190     {"Floating Point Registers", "fpu", k_num_fpr_registers_i386,
191      g_fpu_regnums_i386},
192     {"Advanced Vector Extensions", "avx", k_num_avx_registers_i386,
193      g_avx_regnums_i386},
194     { "Memory Protection Extensions", "mpx", k_num_mpx_registers_i386,
195      g_mpx_regnums_i386}};
196 
197 // Register sets for x86 64-bit.
198 static const RegisterSet g_reg_sets_x86_64[k_num_register_sets] = {
199     {"General Purpose Registers", "gpr", k_num_gpr_registers_x86_64,
200      g_gpr_regnums_x86_64},
201     {"Floating Point Registers", "fpu", k_num_fpr_registers_x86_64,
202      g_fpu_regnums_x86_64},
203     {"Advanced Vector Extensions", "avx", k_num_avx_registers_x86_64,
204      g_avx_regnums_x86_64},
205     { "Memory Protection Extensions", "mpx", k_num_mpx_registers_x86_64,
206      g_mpx_regnums_x86_64}};
207 }
208 
209 #define REG_CONTEXT_SIZE (GetRegisterInfoInterface().GetGPRSize() + sizeof(FPR))
210 
211 // ----------------------------------------------------------------------------
212 // Required ptrace defines.
213 // ----------------------------------------------------------------------------
214 
215 // Support ptrace extensions even when compiled without required kernel support
216 #ifndef NT_X86_XSTATE
217 #define NT_X86_XSTATE 0x202
218 #endif
219 #ifndef NT_PRXFPREG
220 #define NT_PRXFPREG 0x46e62b7f
221 #endif
222 
223 // On x86_64 NT_PRFPREG is used to access the FXSAVE area. On i386, we need to
224 // use NT_PRXFPREG.
225 static inline unsigned int fxsr_regset(const ArchSpec &arch) {
226   return arch.GetAddressByteSize() == 8 ? NT_PRFPREG : NT_PRXFPREG;
227 }
228 
229 // ----------------------------------------------------------------------------
230 // Required MPX define.
231 // ----------------------------------------------------------------------------
232 
233 // Support MPX extensions also if compiled with compiler without MPX support.
234 #ifndef bit_MPX
235 #define bit_MPX 0x4000
236 #endif
237 
238 // ----------------------------------------------------------------------------
239 // XCR0 extended register sets masks.
240 // ----------------------------------------------------------------------------
241 #define mask_XSTATE_AVX (1ULL << 2)
242 #define mask_XSTATE_BNDREGS (1ULL << 3)
243 #define mask_XSTATE_BNDCFG (1ULL << 4)
244 #define mask_XSTATE_MPX (mask_XSTATE_BNDREGS | mask_XSTATE_BNDCFG)
245 
246 NativeRegisterContextLinux *
247 NativeRegisterContextLinux::CreateHostNativeRegisterContextLinux(
248     const ArchSpec &target_arch, NativeThreadProtocol &native_thread,
249     uint32_t concrete_frame_idx) {
250   return new NativeRegisterContextLinux_x86_64(target_arch, native_thread,
251                                                concrete_frame_idx);
252 }
253 
254 // ----------------------------------------------------------------------------
255 // NativeRegisterContextLinux_x86_64 members.
256 // ----------------------------------------------------------------------------
257 
258 static RegisterInfoInterface *
259 CreateRegisterInfoInterface(const ArchSpec &target_arch) {
260   if (HostInfo::GetArchitecture().GetAddressByteSize() == 4) {
261     // 32-bit hosts run with a RegisterContextLinux_i386 context.
262     return new RegisterContextLinux_i386(target_arch);
263   } else {
264     assert((HostInfo::GetArchitecture().GetAddressByteSize() == 8) &&
265            "Register setting path assumes this is a 64-bit host");
266     // X86_64 hosts know how to work with 64-bit and 32-bit EXEs using the
267     // x86_64 register context.
268     return new RegisterContextLinux_x86_64(target_arch);
269   }
270 }
271 
272 NativeRegisterContextLinux_x86_64::NativeRegisterContextLinux_x86_64(
273     const ArchSpec &target_arch, NativeThreadProtocol &native_thread,
274     uint32_t concrete_frame_idx)
275     : NativeRegisterContextLinux(native_thread, concrete_frame_idx,
276                                  CreateRegisterInfoInterface(target_arch)),
277       m_xstate_type(XStateType::Invalid), m_fpr(), m_iovec(), m_ymm_set(),
278       m_mpx_set(), m_reg_info(), m_gpr_x86_64() {
279   // Set up data about ranges of valid registers.
280   switch (target_arch.GetMachine()) {
281   case llvm::Triple::x86:
282     m_reg_info.num_registers = k_num_registers_i386;
283     m_reg_info.num_gpr_registers = k_num_gpr_registers_i386;
284     m_reg_info.num_fpr_registers = k_num_fpr_registers_i386;
285     m_reg_info.num_avx_registers = k_num_avx_registers_i386;
286     m_reg_info.num_mpx_registers = k_num_mpx_registers_i386;
287     m_reg_info.last_gpr = k_last_gpr_i386;
288     m_reg_info.first_fpr = k_first_fpr_i386;
289     m_reg_info.last_fpr = k_last_fpr_i386;
290     m_reg_info.first_st = lldb_st0_i386;
291     m_reg_info.last_st = lldb_st7_i386;
292     m_reg_info.first_mm = lldb_mm0_i386;
293     m_reg_info.last_mm = lldb_mm7_i386;
294     m_reg_info.first_xmm = lldb_xmm0_i386;
295     m_reg_info.last_xmm = lldb_xmm7_i386;
296     m_reg_info.first_ymm = lldb_ymm0_i386;
297     m_reg_info.last_ymm = lldb_ymm7_i386;
298     m_reg_info.first_mpxr = lldb_bnd0_i386;
299     m_reg_info.last_mpxr = lldb_bnd3_i386;
300     m_reg_info.first_mpxc = lldb_bndcfgu_i386;
301     m_reg_info.last_mpxc = lldb_bndstatus_i386;
302     m_reg_info.first_dr = lldb_dr0_i386;
303     m_reg_info.gpr_flags = lldb_eflags_i386;
304     break;
305   case llvm::Triple::x86_64:
306     m_reg_info.num_registers = k_num_registers_x86_64;
307     m_reg_info.num_gpr_registers = k_num_gpr_registers_x86_64;
308     m_reg_info.num_fpr_registers = k_num_fpr_registers_x86_64;
309     m_reg_info.num_avx_registers = k_num_avx_registers_x86_64;
310     m_reg_info.num_mpx_registers = k_num_mpx_registers_x86_64;
311     m_reg_info.last_gpr = k_last_gpr_x86_64;
312     m_reg_info.first_fpr = k_first_fpr_x86_64;
313     m_reg_info.last_fpr = k_last_fpr_x86_64;
314     m_reg_info.first_st = lldb_st0_x86_64;
315     m_reg_info.last_st = lldb_st7_x86_64;
316     m_reg_info.first_mm = lldb_mm0_x86_64;
317     m_reg_info.last_mm = lldb_mm7_x86_64;
318     m_reg_info.first_xmm = lldb_xmm0_x86_64;
319     m_reg_info.last_xmm = lldb_xmm15_x86_64;
320     m_reg_info.first_ymm = lldb_ymm0_x86_64;
321     m_reg_info.last_ymm = lldb_ymm15_x86_64;
322     m_reg_info.first_mpxr = lldb_bnd0_x86_64;
323     m_reg_info.last_mpxr = lldb_bnd3_x86_64;
324     m_reg_info.first_mpxc = lldb_bndcfgu_x86_64;
325     m_reg_info.last_mpxc = lldb_bndstatus_x86_64;
326     m_reg_info.first_dr = lldb_dr0_x86_64;
327     m_reg_info.gpr_flags = lldb_rflags_x86_64;
328     break;
329   default:
330     assert(false && "Unhandled target architecture.");
331     break;
332   }
333 
334   // Initialize m_iovec to point to the buffer and buffer size
335   // using the conventions of Berkeley style UIO structures, as required
336   // by PTRACE extensions.
337   m_iovec.iov_base = &m_fpr.xstate.xsave;
338   m_iovec.iov_len = sizeof(m_fpr.xstate.xsave);
339 
340   // Clear out the FPR state.
341   ::memset(&m_fpr, 0, sizeof(FPR));
342 
343   // Store byte offset of fctrl (i.e. first register of FPR)
344   const RegisterInfo *reg_info_fctrl = GetRegisterInfoByName("fctrl");
345   m_fctrl_offset_in_userarea = reg_info_fctrl->byte_offset;
346 }
347 
348 // CONSIDER after local and llgs debugging are merged, register set support can
349 // be moved into a base x86-64 class with IsRegisterSetAvailable made virtual.
350 uint32_t NativeRegisterContextLinux_x86_64::GetRegisterSetCount() const {
351   uint32_t sets = 0;
352   for (uint32_t set_index = 0; set_index < k_num_register_sets; ++set_index) {
353     if (IsRegisterSetAvailable(set_index))
354       ++sets;
355   }
356 
357   return sets;
358 }
359 
360 uint32_t NativeRegisterContextLinux_x86_64::GetUserRegisterCount() const {
361   uint32_t count = 0;
362   for (uint32_t set_index = 0; set_index < k_num_register_sets; ++set_index) {
363     const RegisterSet *set = GetRegisterSet(set_index);
364     if (set)
365       count += set->num_registers;
366   }
367   return count;
368 }
369 
370 const RegisterSet *
371 NativeRegisterContextLinux_x86_64::GetRegisterSet(uint32_t set_index) const {
372   if (!IsRegisterSetAvailable(set_index))
373     return nullptr;
374 
375   switch (GetRegisterInfoInterface().GetTargetArchitecture().GetMachine()) {
376   case llvm::Triple::x86:
377     return &g_reg_sets_i386[set_index];
378   case llvm::Triple::x86_64:
379     return &g_reg_sets_x86_64[set_index];
380   default:
381     assert(false && "Unhandled target architecture.");
382     return nullptr;
383   }
384 
385   return nullptr;
386 }
387 
388 Status
389 NativeRegisterContextLinux_x86_64::ReadRegister(const RegisterInfo *reg_info,
390                                                 RegisterValue &reg_value) {
391   Status error;
392 
393   if (!reg_info) {
394     error.SetErrorString("reg_info NULL");
395     return error;
396   }
397 
398   const uint32_t reg = reg_info->kinds[lldb::eRegisterKindLLDB];
399   if (reg == LLDB_INVALID_REGNUM) {
400     // This is likely an internal register for lldb use only and should not be
401     // directly queried.
402     error.SetErrorStringWithFormat("register \"%s\" is an internal-only lldb "
403                                    "register, cannot read directly",
404                                    reg_info->name);
405     return error;
406   }
407 
408   if (IsFPR(reg) || IsAVX(reg) || IsMPX(reg)) {
409     error = ReadFPR();
410     if (error.Fail())
411       return error;
412   } else {
413     uint32_t full_reg = reg;
414     bool is_subreg = reg_info->invalidate_regs &&
415                      (reg_info->invalidate_regs[0] != LLDB_INVALID_REGNUM);
416 
417     if (is_subreg) {
418       // Read the full aligned 64-bit register.
419       full_reg = reg_info->invalidate_regs[0];
420     }
421 
422     error = ReadRegisterRaw(full_reg, reg_value);
423 
424     if (error.Success()) {
425       // If our read was not aligned (for ah,bh,ch,dh), shift our returned value
426       // one byte to the right.
427       if (is_subreg && (reg_info->byte_offset & 0x1))
428         reg_value.SetUInt64(reg_value.GetAsUInt64() >> 8);
429 
430       // If our return byte size was greater than the return value reg size,
431       // then
432       // use the type specified by reg_info rather than the uint64_t default
433       if (reg_value.GetByteSize() > reg_info->byte_size)
434         reg_value.SetType(reg_info);
435     }
436     return error;
437   }
438 
439   if (reg_info->encoding == lldb::eEncodingVector) {
440     lldb::ByteOrder byte_order = GetByteOrder();
441 
442     if (byte_order != lldb::eByteOrderInvalid) {
443       if (reg >= m_reg_info.first_st && reg <= m_reg_info.last_st)
444         reg_value.SetBytes(
445             m_fpr.xstate.fxsave.stmm[reg - m_reg_info.first_st].bytes,
446             reg_info->byte_size, byte_order);
447       if (reg >= m_reg_info.first_mm && reg <= m_reg_info.last_mm)
448         reg_value.SetBytes(
449             m_fpr.xstate.fxsave.stmm[reg - m_reg_info.first_mm].bytes,
450             reg_info->byte_size, byte_order);
451       if (reg >= m_reg_info.first_xmm && reg <= m_reg_info.last_xmm)
452         reg_value.SetBytes(
453             m_fpr.xstate.fxsave.xmm[reg - m_reg_info.first_xmm].bytes,
454             reg_info->byte_size, byte_order);
455       if (reg >= m_reg_info.first_ymm && reg <= m_reg_info.last_ymm) {
456         // Concatenate ymm using the register halves in xmm.bytes and ymmh.bytes
457         if (CopyXSTATEtoYMM(reg, byte_order))
458           reg_value.SetBytes(m_ymm_set.ymm[reg - m_reg_info.first_ymm].bytes,
459                              reg_info->byte_size, byte_order);
460         else {
461           error.SetErrorString("failed to copy ymm register value");
462           return error;
463         }
464       }
465       if (reg >= m_reg_info.first_mpxr && reg <= m_reg_info.last_mpxr) {
466         if (CopyXSTATEtoMPX(reg))
467           reg_value.SetBytes(m_mpx_set.mpxr[reg - m_reg_info.first_mpxr].bytes,
468                              reg_info->byte_size, byte_order);
469         else {
470           error.SetErrorString("failed to copy mpx register value");
471           return error;
472         }
473       }
474       if (reg >= m_reg_info.first_mpxc && reg <= m_reg_info.last_mpxc) {
475         if (CopyXSTATEtoMPX(reg))
476           reg_value.SetBytes(m_mpx_set.mpxc[reg - m_reg_info.first_mpxc].bytes,
477                              reg_info->byte_size, byte_order);
478         else {
479           error.SetErrorString("failed to copy mpx register value");
480           return error;
481         }
482       }
483 
484       if (reg_value.GetType() != RegisterValue::eTypeBytes)
485         error.SetErrorString(
486             "write failed - type was expected to be RegisterValue::eTypeBytes");
487 
488       return error;
489     }
490 
491     error.SetErrorString("byte order is invalid");
492     return error;
493   }
494 
495   // Get pointer to m_fpr.xstate.fxsave variable and set the data from it.
496 
497   // Byte offsets of all registers are calculated wrt 'UserArea' structure.
498   // However, ReadFPR() reads fpu registers {using ptrace(PTRACE_GETFPREGS,..)}
499   // and stores them in 'm_fpr' (of type FPR structure). To extract values of
500   // fpu
501   // registers, m_fpr should be read at byte offsets calculated wrt to FPR
502   // structure.
503 
504   // Since, FPR structure is also one of the member of UserArea structure.
505   // byte_offset(fpu wrt FPR) = byte_offset(fpu wrt UserArea) -
506   // byte_offset(fctrl wrt UserArea)
507   assert((reg_info->byte_offset - m_fctrl_offset_in_userarea) < sizeof(m_fpr));
508   uint8_t *src =
509       (uint8_t *)&m_fpr + reg_info->byte_offset - m_fctrl_offset_in_userarea;
510   switch (reg_info->byte_size) {
511   case 1:
512     reg_value.SetUInt8(*(uint8_t *)src);
513     break;
514   case 2:
515     reg_value.SetUInt16(*(uint16_t *)src);
516     break;
517   case 4:
518     reg_value.SetUInt32(*(uint32_t *)src);
519     break;
520   case 8:
521     reg_value.SetUInt64(*(uint64_t *)src);
522     break;
523   default:
524     assert(false && "Unhandled data size.");
525     error.SetErrorStringWithFormat("unhandled byte size: %" PRIu32,
526                                    reg_info->byte_size);
527     break;
528   }
529 
530   return error;
531 }
532 
533 Status NativeRegisterContextLinux_x86_64::WriteRegister(
534     const RegisterInfo *reg_info, const RegisterValue &reg_value) {
535   assert(reg_info && "reg_info is null");
536 
537   const uint32_t reg_index = reg_info->kinds[lldb::eRegisterKindLLDB];
538   if (reg_index == LLDB_INVALID_REGNUM)
539     return Status("no lldb regnum for %s", reg_info && reg_info->name
540                                                ? reg_info->name
541                                                : "<unknown register>");
542 
543   if (IsGPR(reg_index))
544     return WriteRegisterRaw(reg_index, reg_value);
545 
546   if (IsFPR(reg_index) || IsAVX(reg_index) || IsMPX(reg_index)) {
547     if (reg_info->encoding == lldb::eEncodingVector) {
548       if (reg_index >= m_reg_info.first_st && reg_index <= m_reg_info.last_st)
549         ::memcpy(
550             m_fpr.xstate.fxsave.stmm[reg_index - m_reg_info.first_st].bytes,
551             reg_value.GetBytes(), reg_value.GetByteSize());
552 
553       if (reg_index >= m_reg_info.first_mm && reg_index <= m_reg_info.last_mm)
554         ::memcpy(
555             m_fpr.xstate.fxsave.stmm[reg_index - m_reg_info.first_mm].bytes,
556             reg_value.GetBytes(), reg_value.GetByteSize());
557 
558       if (reg_index >= m_reg_info.first_xmm && reg_index <= m_reg_info.last_xmm)
559         ::memcpy(
560             m_fpr.xstate.fxsave.xmm[reg_index - m_reg_info.first_xmm].bytes,
561             reg_value.GetBytes(), reg_value.GetByteSize());
562 
563       if (reg_index >= m_reg_info.first_ymm &&
564           reg_index <= m_reg_info.last_ymm) {
565         // Store ymm register content, and split into the register halves in
566         // xmm.bytes and ymmh.bytes
567         ::memcpy(m_ymm_set.ymm[reg_index - m_reg_info.first_ymm].bytes,
568                  reg_value.GetBytes(), reg_value.GetByteSize());
569         if (!CopyYMMtoXSTATE(reg_index, GetByteOrder()))
570           return Status("CopyYMMtoXSTATE() failed");
571       }
572 
573       if (reg_index >= m_reg_info.first_mpxr &&
574           reg_index <= m_reg_info.last_mpxr) {
575         ::memcpy(m_mpx_set.mpxr[reg_index - m_reg_info.first_mpxr].bytes,
576                  reg_value.GetBytes(), reg_value.GetByteSize());
577         if (!CopyMPXtoXSTATE(reg_index))
578           return Status("CopyMPXtoXSTATE() failed");
579       }
580 
581       if (reg_index >= m_reg_info.first_mpxc &&
582           reg_index <= m_reg_info.last_mpxc) {
583         ::memcpy(m_mpx_set.mpxc[reg_index - m_reg_info.first_mpxc].bytes,
584                  reg_value.GetBytes(), reg_value.GetByteSize());
585         if (!CopyMPXtoXSTATE(reg_index))
586           return Status("CopyMPXtoXSTATE() failed");
587       }
588     } else {
589       // Get pointer to m_fpr.xstate.fxsave variable and set the data to it.
590 
591       // Byte offsets of all registers are calculated wrt 'UserArea' structure.
592       // However, WriteFPR() takes m_fpr (of type FPR structure) and writes only
593       // fpu
594       // registers using ptrace(PTRACE_SETFPREGS,..) API. Hence fpu registers
595       // should
596       // be written in m_fpr at byte offsets calculated wrt FPR structure.
597 
598       // Since, FPR structure is also one of the member of UserArea structure.
599       // byte_offset(fpu wrt FPR) = byte_offset(fpu wrt UserArea) -
600       // byte_offset(fctrl wrt UserArea)
601       assert((reg_info->byte_offset - m_fctrl_offset_in_userarea) <
602              sizeof(m_fpr));
603       uint8_t *dst = (uint8_t *)&m_fpr + reg_info->byte_offset -
604                      m_fctrl_offset_in_userarea;
605       switch (reg_info->byte_size) {
606       case 1:
607         *(uint8_t *)dst = reg_value.GetAsUInt8();
608         break;
609       case 2:
610         *(uint16_t *)dst = reg_value.GetAsUInt16();
611         break;
612       case 4:
613         *(uint32_t *)dst = reg_value.GetAsUInt32();
614         break;
615       case 8:
616         *(uint64_t *)dst = reg_value.GetAsUInt64();
617         break;
618       default:
619         assert(false && "Unhandled data size.");
620         return Status("unhandled register data size %" PRIu32,
621                       reg_info->byte_size);
622       }
623     }
624 
625     Status error = WriteFPR();
626     if (error.Fail())
627       return error;
628 
629     if (IsAVX(reg_index)) {
630       if (!CopyYMMtoXSTATE(reg_index, GetByteOrder()))
631         return Status("CopyYMMtoXSTATE() failed");
632     }
633 
634     if (IsMPX(reg_index)) {
635       if (!CopyMPXtoXSTATE(reg_index))
636         return Status("CopyMPXtoXSTATE() failed");
637     }
638     return Status();
639   }
640   return Status("failed - register wasn't recognized to be a GPR or an FPR, "
641                 "write strategy unknown");
642 }
643 
644 Status NativeRegisterContextLinux_x86_64::ReadAllRegisterValues(
645     lldb::DataBufferSP &data_sp) {
646   Status error;
647 
648   data_sp.reset(new DataBufferHeap(REG_CONTEXT_SIZE, 0));
649   error = ReadGPR();
650   if (error.Fail())
651     return error;
652 
653   error = ReadFPR();
654   if (error.Fail())
655     return error;
656 
657   uint8_t *dst = data_sp->GetBytes();
658   ::memcpy(dst, &m_gpr_x86_64, GetRegisterInfoInterface().GetGPRSize());
659   dst += GetRegisterInfoInterface().GetGPRSize();
660   if (m_xstate_type == XStateType::FXSAVE)
661     ::memcpy(dst, &m_fpr.xstate.fxsave, sizeof(m_fpr.xstate.fxsave));
662   else if (m_xstate_type == XStateType::XSAVE) {
663     lldb::ByteOrder byte_order = GetByteOrder();
664 
665     if (IsCPUFeatureAvailable(RegSet::avx)) {
666       // Assemble the YMM register content from the register halves.
667       for (uint32_t reg = m_reg_info.first_ymm; reg <= m_reg_info.last_ymm;
668            ++reg) {
669         if (!CopyXSTATEtoYMM(reg, byte_order)) {
670           error.SetErrorStringWithFormat(
671               "NativeRegisterContextLinux_x86_64::%s "
672               "CopyXSTATEtoYMM() failed for reg num "
673               "%" PRIu32,
674               __FUNCTION__, reg);
675           return error;
676         }
677       }
678     }
679 
680     if (IsCPUFeatureAvailable(RegSet::mpx)) {
681       for (uint32_t reg = m_reg_info.first_mpxr; reg <= m_reg_info.last_mpxc;
682            ++reg) {
683         if (!CopyXSTATEtoMPX(reg)) {
684           error.SetErrorStringWithFormat(
685               "NativeRegisterContextLinux_x86_64::%s "
686               "CopyXSTATEtoMPX() failed for reg num "
687               "%" PRIu32,
688               __FUNCTION__, reg);
689           return error;
690         }
691       }
692     }
693     // Copy the extended register state including the assembled ymm registers.
694     ::memcpy(dst, &m_fpr, sizeof(m_fpr));
695   } else {
696     assert(false && "how do we save the floating point registers?");
697     error.SetErrorString("unsure how to save the floating point registers");
698   }
699   /** The following code is specific to Linux x86 based architectures,
700    *  where the register orig_eax (32 bit)/orig_rax (64 bit) is set to
701    *  -1 to solve the bug 23659, such a setting prevents the automatic
702    *  decrement of the instruction pointer which was causing the SIGILL
703    *  exception.
704    * **/
705 
706   RegisterValue value((uint64_t)-1);
707   const RegisterInfo *reg_info =
708       GetRegisterInfoInterface().GetDynamicRegisterInfo("orig_eax");
709   if (reg_info == nullptr)
710     reg_info = GetRegisterInfoInterface().GetDynamicRegisterInfo("orig_rax");
711 
712   if (reg_info != nullptr)
713     return DoWriteRegisterValue(reg_info->byte_offset, reg_info->name, value);
714 
715   return error;
716 }
717 
718 Status NativeRegisterContextLinux_x86_64::WriteAllRegisterValues(
719     const lldb::DataBufferSP &data_sp) {
720   Status error;
721 
722   if (!data_sp) {
723     error.SetErrorStringWithFormat(
724         "NativeRegisterContextLinux_x86_64::%s invalid data_sp provided",
725         __FUNCTION__);
726     return error;
727   }
728 
729   if (data_sp->GetByteSize() != REG_CONTEXT_SIZE) {
730     error.SetErrorStringWithFormatv(
731         "data_sp contained mismatched data size, expected {0}, actual {1}",
732         REG_CONTEXT_SIZE, data_sp->GetByteSize());
733     return error;
734   }
735 
736   uint8_t *src = data_sp->GetBytes();
737   if (src == nullptr) {
738     error.SetErrorStringWithFormat("NativeRegisterContextLinux_x86_64::%s "
739                                    "DataBuffer::GetBytes() returned a null "
740                                    "pointer",
741                                    __FUNCTION__);
742     return error;
743   }
744   ::memcpy(&m_gpr_x86_64, src, GetRegisterInfoInterface().GetGPRSize());
745 
746   error = WriteGPR();
747   if (error.Fail())
748     return error;
749 
750   src += GetRegisterInfoInterface().GetGPRSize();
751   if (m_xstate_type == XStateType::FXSAVE)
752     ::memcpy(&m_fpr.xstate.fxsave, src, sizeof(m_fpr.xstate.fxsave));
753   else if (m_xstate_type == XStateType::XSAVE)
754     ::memcpy(&m_fpr.xstate.xsave, src, sizeof(m_fpr.xstate.xsave));
755 
756   error = WriteFPR();
757   if (error.Fail())
758     return error;
759 
760   if (m_xstate_type == XStateType::XSAVE) {
761     lldb::ByteOrder byte_order = GetByteOrder();
762 
763     if (IsCPUFeatureAvailable(RegSet::avx)) {
764       // Parse the YMM register content from the register halves.
765       for (uint32_t reg = m_reg_info.first_ymm; reg <= m_reg_info.last_ymm;
766            ++reg) {
767         if (!CopyYMMtoXSTATE(reg, byte_order)) {
768           error.SetErrorStringWithFormat(
769               "NativeRegisterContextLinux_x86_64::%s "
770               "CopyYMMtoXSTATE() failed for reg num "
771               "%" PRIu32,
772               __FUNCTION__, reg);
773           return error;
774         }
775       }
776     }
777 
778     if (IsCPUFeatureAvailable(RegSet::mpx)) {
779       for (uint32_t reg = m_reg_info.first_mpxr; reg <= m_reg_info.last_mpxc;
780            ++reg) {
781         if (!CopyMPXtoXSTATE(reg)) {
782           error.SetErrorStringWithFormat(
783               "NativeRegisterContextLinux_x86_64::%s "
784               "CopyMPXtoXSTATE() failed for reg num "
785               "%" PRIu32,
786               __FUNCTION__, reg);
787           return error;
788         }
789       }
790     }
791   }
792 
793   return error;
794 }
795 
796 bool NativeRegisterContextLinux_x86_64::IsCPUFeatureAvailable(
797     RegSet feature_code) const {
798   if (m_xstate_type == XStateType::Invalid) {
799     if (const_cast<NativeRegisterContextLinux_x86_64 *>(this)->ReadFPR().Fail())
800       return false;
801   }
802   switch (feature_code) {
803   case RegSet::gpr:
804   case RegSet::fpu:
805     return true;
806   case RegSet::avx: // Check if CPU has AVX and if there is kernel support, by
807                     // reading in the XCR0 area of XSAVE.
808     if ((m_fpr.xstate.xsave.i387.xcr0 & mask_XSTATE_AVX) == mask_XSTATE_AVX)
809       return true;
810      break;
811   case RegSet::mpx: // Check if CPU has MPX and if there is kernel support, by
812                     // reading in the XCR0 area of XSAVE.
813     if ((m_fpr.xstate.xsave.i387.xcr0 & mask_XSTATE_MPX) == mask_XSTATE_MPX)
814       return true;
815     break;
816   }
817   return false;
818 }
819 
820 bool NativeRegisterContextLinux_x86_64::IsRegisterSetAvailable(
821     uint32_t set_index) const {
822   uint32_t num_sets = k_num_register_sets - k_num_extended_register_sets;
823 
824   switch (static_cast<RegSet>(set_index)) {
825   case RegSet::gpr:
826   case RegSet::fpu:
827     return (set_index < num_sets);
828   case RegSet::avx:
829     return IsCPUFeatureAvailable(RegSet::avx);
830   case RegSet::mpx:
831     return IsCPUFeatureAvailable(RegSet::mpx);
832   }
833   return false;
834 }
835 
836 bool NativeRegisterContextLinux_x86_64::IsGPR(uint32_t reg_index) const {
837   // GPRs come first.
838   return reg_index <= m_reg_info.last_gpr;
839 }
840 
841 bool NativeRegisterContextLinux_x86_64::IsFPR(uint32_t reg_index) const {
842   return (m_reg_info.first_fpr <= reg_index &&
843           reg_index <= m_reg_info.last_fpr);
844 }
845 
846 Status NativeRegisterContextLinux_x86_64::WriteFPR() {
847   switch (m_xstate_type) {
848   case XStateType::FXSAVE:
849     return WriteRegisterSet(
850         &m_iovec, sizeof(m_fpr.xstate.xsave),
851         fxsr_regset(GetRegisterInfoInterface().GetTargetArchitecture()));
852   case XStateType::XSAVE:
853     return WriteRegisterSet(&m_iovec, sizeof(m_fpr.xstate.xsave),
854                             NT_X86_XSTATE);
855   default:
856     return Status("Unrecognized FPR type.");
857   }
858 }
859 
860 bool NativeRegisterContextLinux_x86_64::IsAVX(uint32_t reg_index) const {
861   if (!IsCPUFeatureAvailable(RegSet::avx))
862     return false;
863   return (m_reg_info.first_ymm <= reg_index &&
864           reg_index <= m_reg_info.last_ymm);
865 }
866 
867 bool NativeRegisterContextLinux_x86_64::CopyXSTATEtoYMM(
868     uint32_t reg_index, lldb::ByteOrder byte_order) {
869   if (!IsAVX(reg_index))
870     return false;
871 
872   if (byte_order == lldb::eByteOrderLittle) {
873     ::memcpy(m_ymm_set.ymm[reg_index - m_reg_info.first_ymm].bytes,
874              m_fpr.xstate.fxsave.xmm[reg_index - m_reg_info.first_ymm].bytes,
875              sizeof(XMMReg));
876     ::memcpy(m_ymm_set.ymm[reg_index - m_reg_info.first_ymm].bytes +
877                  sizeof(XMMReg),
878              m_fpr.xstate.xsave.ymmh[reg_index - m_reg_info.first_ymm].bytes,
879              sizeof(YMMHReg));
880     return true;
881   }
882 
883   if (byte_order == lldb::eByteOrderBig) {
884     ::memcpy(m_ymm_set.ymm[reg_index - m_reg_info.first_ymm].bytes +
885                  sizeof(XMMReg),
886              m_fpr.xstate.fxsave.xmm[reg_index - m_reg_info.first_ymm].bytes,
887              sizeof(XMMReg));
888     ::memcpy(m_ymm_set.ymm[reg_index - m_reg_info.first_ymm].bytes,
889              m_fpr.xstate.xsave.ymmh[reg_index - m_reg_info.first_ymm].bytes,
890              sizeof(YMMHReg));
891     return true;
892   }
893   return false; // unsupported or invalid byte order
894 }
895 
896 bool NativeRegisterContextLinux_x86_64::CopyYMMtoXSTATE(
897     uint32_t reg, lldb::ByteOrder byte_order) {
898   if (!IsAVX(reg))
899     return false;
900 
901   if (byte_order == lldb::eByteOrderLittle) {
902     ::memcpy(m_fpr.xstate.fxsave.xmm[reg - m_reg_info.first_ymm].bytes,
903              m_ymm_set.ymm[reg - m_reg_info.first_ymm].bytes, sizeof(XMMReg));
904     ::memcpy(m_fpr.xstate.xsave.ymmh[reg - m_reg_info.first_ymm].bytes,
905              m_ymm_set.ymm[reg - m_reg_info.first_ymm].bytes + sizeof(XMMReg),
906              sizeof(YMMHReg));
907     return true;
908   }
909 
910   if (byte_order == lldb::eByteOrderBig) {
911     ::memcpy(m_fpr.xstate.fxsave.xmm[reg - m_reg_info.first_ymm].bytes,
912              m_ymm_set.ymm[reg - m_reg_info.first_ymm].bytes + sizeof(XMMReg),
913              sizeof(XMMReg));
914     ::memcpy(m_fpr.xstate.xsave.ymmh[reg - m_reg_info.first_ymm].bytes,
915              m_ymm_set.ymm[reg - m_reg_info.first_ymm].bytes, sizeof(YMMHReg));
916     return true;
917   }
918   return false; // unsupported or invalid byte order
919 }
920 
921 void *NativeRegisterContextLinux_x86_64::GetFPRBuffer() {
922   switch (m_xstate_type) {
923   case XStateType::FXSAVE:
924     return &m_fpr.xstate.fxsave;
925   case XStateType::XSAVE:
926     return &m_iovec;
927   default:
928     return nullptr;
929   }
930 }
931 
932 size_t NativeRegisterContextLinux_x86_64::GetFPRSize() {
933   switch (m_xstate_type) {
934   case XStateType::FXSAVE:
935     return sizeof(m_fpr.xstate.fxsave);
936   case XStateType::XSAVE:
937     return sizeof(m_iovec);
938   default:
939     return 0;
940   }
941 }
942 
943 Status NativeRegisterContextLinux_x86_64::ReadFPR() {
944   Status error;
945 
946   // Probe XSAVE and if it is not supported fall back to FXSAVE.
947   if (m_xstate_type != XStateType::FXSAVE) {
948     error =
949         ReadRegisterSet(&m_iovec, sizeof(m_fpr.xstate.xsave), NT_X86_XSTATE);
950     if (!error.Fail()) {
951       m_xstate_type = XStateType::XSAVE;
952       return error;
953     }
954   }
955   error = ReadRegisterSet(
956       &m_iovec, sizeof(m_fpr.xstate.xsave),
957       fxsr_regset(GetRegisterInfoInterface().GetTargetArchitecture()));
958   if (!error.Fail()) {
959     m_xstate_type = XStateType::FXSAVE;
960     return error;
961   }
962   return Status("Unrecognized FPR type.");
963 }
964 
965 bool NativeRegisterContextLinux_x86_64::IsMPX(uint32_t reg_index) const {
966   if (!IsCPUFeatureAvailable(RegSet::mpx))
967     return false;
968   return (m_reg_info.first_mpxr <= reg_index &&
969           reg_index <= m_reg_info.last_mpxc);
970 }
971 
972 bool NativeRegisterContextLinux_x86_64::CopyXSTATEtoMPX(uint32_t reg) {
973   if (!IsMPX(reg))
974     return false;
975 
976   if (reg >= m_reg_info.first_mpxr && reg <= m_reg_info.last_mpxr) {
977     ::memcpy(m_mpx_set.mpxr[reg - m_reg_info.first_mpxr].bytes,
978              m_fpr.xstate.xsave.mpxr[reg - m_reg_info.first_mpxr].bytes,
979              sizeof(MPXReg));
980   } else {
981     ::memcpy(m_mpx_set.mpxc[reg - m_reg_info.first_mpxc].bytes,
982              m_fpr.xstate.xsave.mpxc[reg - m_reg_info.first_mpxc].bytes,
983              sizeof(MPXCsr));
984   }
985   return true;
986 }
987 
988 bool NativeRegisterContextLinux_x86_64::CopyMPXtoXSTATE(uint32_t reg) {
989   if (!IsMPX(reg))
990     return false;
991 
992   if (reg >= m_reg_info.first_mpxr && reg <= m_reg_info.last_mpxr) {
993     ::memcpy(m_fpr.xstate.xsave.mpxr[reg - m_reg_info.first_mpxr].bytes,
994              m_mpx_set.mpxr[reg - m_reg_info.first_mpxr].bytes, sizeof(MPXReg));
995   } else {
996     ::memcpy(m_fpr.xstate.xsave.mpxc[reg - m_reg_info.first_mpxc].bytes,
997              m_mpx_set.mpxc[reg - m_reg_info.first_mpxc].bytes, sizeof(MPXCsr));
998   }
999   return true;
1000 }
1001 
1002 Status NativeRegisterContextLinux_x86_64::IsWatchpointHit(uint32_t wp_index,
1003                                                           bool &is_hit) {
1004   if (wp_index >= NumSupportedHardwareWatchpoints())
1005     return Status("Watchpoint index out of range");
1006 
1007   RegisterValue reg_value;
1008   Status error = ReadRegisterRaw(m_reg_info.first_dr + 6, reg_value);
1009   if (error.Fail()) {
1010     is_hit = false;
1011     return error;
1012   }
1013 
1014   uint64_t status_bits = reg_value.GetAsUInt64();
1015 
1016   is_hit = status_bits & (1 << wp_index);
1017 
1018   return error;
1019 }
1020 
1021 Status NativeRegisterContextLinux_x86_64::GetWatchpointHitIndex(
1022     uint32_t &wp_index, lldb::addr_t trap_addr) {
1023   uint32_t num_hw_wps = NumSupportedHardwareWatchpoints();
1024   for (wp_index = 0; wp_index < num_hw_wps; ++wp_index) {
1025     bool is_hit;
1026     Status error = IsWatchpointHit(wp_index, is_hit);
1027     if (error.Fail()) {
1028       wp_index = LLDB_INVALID_INDEX32;
1029       return error;
1030     } else if (is_hit) {
1031       return error;
1032     }
1033   }
1034   wp_index = LLDB_INVALID_INDEX32;
1035   return Status();
1036 }
1037 
1038 Status NativeRegisterContextLinux_x86_64::IsWatchpointVacant(uint32_t wp_index,
1039                                                              bool &is_vacant) {
1040   if (wp_index >= NumSupportedHardwareWatchpoints())
1041     return Status("Watchpoint index out of range");
1042 
1043   RegisterValue reg_value;
1044   Status error = ReadRegisterRaw(m_reg_info.first_dr + 7, reg_value);
1045   if (error.Fail()) {
1046     is_vacant = false;
1047     return error;
1048   }
1049 
1050   uint64_t control_bits = reg_value.GetAsUInt64();
1051 
1052   is_vacant = !(control_bits & (1 << (2 * wp_index)));
1053 
1054   return error;
1055 }
1056 
1057 Status NativeRegisterContextLinux_x86_64::SetHardwareWatchpointWithIndex(
1058     lldb::addr_t addr, size_t size, uint32_t watch_flags, uint32_t wp_index) {
1059 
1060   if (wp_index >= NumSupportedHardwareWatchpoints())
1061     return Status("Watchpoint index out of range");
1062 
1063   // Read only watchpoints aren't supported on x86_64. Fall back to read/write
1064   // waitchpoints instead.
1065   // TODO: Add logic to detect when a write happens and ignore that watchpoint
1066   // hit.
1067   if (watch_flags == 0x2)
1068     watch_flags = 0x3;
1069 
1070   if (watch_flags != 0x1 && watch_flags != 0x3)
1071     return Status("Invalid read/write bits for watchpoint");
1072 
1073   if (size != 1 && size != 2 && size != 4 && size != 8)
1074     return Status("Invalid size for watchpoint");
1075 
1076   bool is_vacant;
1077   Status error = IsWatchpointVacant(wp_index, is_vacant);
1078   if (error.Fail())
1079     return error;
1080   if (!is_vacant)
1081     return Status("Watchpoint index not vacant");
1082 
1083   RegisterValue reg_value;
1084   error = ReadRegisterRaw(m_reg_info.first_dr + 7, reg_value);
1085   if (error.Fail())
1086     return error;
1087 
1088   // for watchpoints 0, 1, 2, or 3, respectively,
1089   // set bits 1, 3, 5, or 7
1090   uint64_t enable_bit = 1 << (2 * wp_index);
1091 
1092   // set bits 16-17, 20-21, 24-25, or 28-29
1093   // with 0b01 for write, and 0b11 for read/write
1094   uint64_t rw_bits = watch_flags << (16 + 4 * wp_index);
1095 
1096   // set bits 18-19, 22-23, 26-27, or 30-31
1097   // with 0b00, 0b01, 0b10, or 0b11
1098   // for 1, 2, 8 (if supported), or 4 bytes, respectively
1099   uint64_t size_bits = (size == 8 ? 0x2 : size - 1) << (18 + 4 * wp_index);
1100 
1101   uint64_t bit_mask = (0x3 << (2 * wp_index)) | (0xF << (16 + 4 * wp_index));
1102 
1103   uint64_t control_bits = reg_value.GetAsUInt64() & ~bit_mask;
1104 
1105   control_bits |= enable_bit | rw_bits | size_bits;
1106 
1107   error = WriteRegisterRaw(m_reg_info.first_dr + wp_index, RegisterValue(addr));
1108   if (error.Fail())
1109     return error;
1110 
1111   error =
1112       WriteRegisterRaw(m_reg_info.first_dr + 7, RegisterValue(control_bits));
1113   if (error.Fail())
1114     return error;
1115 
1116   error.Clear();
1117   return error;
1118 }
1119 
1120 bool NativeRegisterContextLinux_x86_64::ClearHardwareWatchpoint(
1121     uint32_t wp_index) {
1122   if (wp_index >= NumSupportedHardwareWatchpoints())
1123     return false;
1124 
1125   RegisterValue reg_value;
1126 
1127   // for watchpoints 0, 1, 2, or 3, respectively,
1128   // clear bits 0, 1, 2, or 3 of the debug status register (DR6)
1129   Status error = ReadRegisterRaw(m_reg_info.first_dr + 6, reg_value);
1130   if (error.Fail())
1131     return false;
1132   uint64_t bit_mask = 1 << wp_index;
1133   uint64_t status_bits = reg_value.GetAsUInt64() & ~bit_mask;
1134   error = WriteRegisterRaw(m_reg_info.first_dr + 6, RegisterValue(status_bits));
1135   if (error.Fail())
1136     return false;
1137 
1138   // for watchpoints 0, 1, 2, or 3, respectively,
1139   // clear bits {0-1,16-19}, {2-3,20-23}, {4-5,24-27}, or {6-7,28-31}
1140   // of the debug control register (DR7)
1141   error = ReadRegisterRaw(m_reg_info.first_dr + 7, reg_value);
1142   if (error.Fail())
1143     return false;
1144   bit_mask = (0x3 << (2 * wp_index)) | (0xF << (16 + 4 * wp_index));
1145   uint64_t control_bits = reg_value.GetAsUInt64() & ~bit_mask;
1146   return WriteRegisterRaw(m_reg_info.first_dr + 7, RegisterValue(control_bits))
1147       .Success();
1148 }
1149 
1150 Status NativeRegisterContextLinux_x86_64::ClearAllHardwareWatchpoints() {
1151   RegisterValue reg_value;
1152 
1153   // clear bits {0-4} of the debug status register (DR6)
1154   Status error = ReadRegisterRaw(m_reg_info.first_dr + 6, reg_value);
1155   if (error.Fail())
1156     return error;
1157   uint64_t bit_mask = 0xF;
1158   uint64_t status_bits = reg_value.GetAsUInt64() & ~bit_mask;
1159   error = WriteRegisterRaw(m_reg_info.first_dr + 6, RegisterValue(status_bits));
1160   if (error.Fail())
1161     return error;
1162 
1163   // clear bits {0-7,16-31} of the debug control register (DR7)
1164   error = ReadRegisterRaw(m_reg_info.first_dr + 7, reg_value);
1165   if (error.Fail())
1166     return error;
1167   bit_mask = 0xFF | (0xFFFF << 16);
1168   uint64_t control_bits = reg_value.GetAsUInt64() & ~bit_mask;
1169   return WriteRegisterRaw(m_reg_info.first_dr + 7, RegisterValue(control_bits));
1170 }
1171 
1172 uint32_t NativeRegisterContextLinux_x86_64::SetHardwareWatchpoint(
1173     lldb::addr_t addr, size_t size, uint32_t watch_flags) {
1174   Log *log(GetLogIfAllCategoriesSet(LIBLLDB_LOG_WATCHPOINTS));
1175   const uint32_t num_hw_watchpoints = NumSupportedHardwareWatchpoints();
1176   for (uint32_t wp_index = 0; wp_index < num_hw_watchpoints; ++wp_index) {
1177     bool is_vacant;
1178     Status error = IsWatchpointVacant(wp_index, is_vacant);
1179     if (is_vacant) {
1180       error = SetHardwareWatchpointWithIndex(addr, size, watch_flags, wp_index);
1181       if (error.Success())
1182         return wp_index;
1183     }
1184     if (error.Fail() && log) {
1185       log->Printf("NativeRegisterContextLinux_x86_64::%s Error: %s",
1186                   __FUNCTION__, error.AsCString());
1187     }
1188   }
1189   return LLDB_INVALID_INDEX32;
1190 }
1191 
1192 lldb::addr_t
1193 NativeRegisterContextLinux_x86_64::GetWatchpointAddress(uint32_t wp_index) {
1194   if (wp_index >= NumSupportedHardwareWatchpoints())
1195     return LLDB_INVALID_ADDRESS;
1196   RegisterValue reg_value;
1197   if (ReadRegisterRaw(m_reg_info.first_dr + wp_index, reg_value).Fail())
1198     return LLDB_INVALID_ADDRESS;
1199   return reg_value.GetAsUInt64();
1200 }
1201 
1202 uint32_t NativeRegisterContextLinux_x86_64::NumSupportedHardwareWatchpoints() {
1203   // Available debug address registers: dr0, dr1, dr2, dr3
1204   return 4;
1205 }
1206 
1207 #endif // defined(__i386__) || defined(__x86_64__)
1208