1 //===-- NativeRegisterContextLinux_x86_64.cpp -----------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #if defined(__i386__) || defined(__x86_64__)
10 
11 #include "NativeRegisterContextLinux_x86_64.h"
12 
13 #include "lldb/Host/HostInfo.h"
14 #include "lldb/Utility/DataBufferHeap.h"
15 #include "lldb/Utility/Log.h"
16 #include "lldb/Utility/RegisterValue.h"
17 #include "lldb/Utility/Status.h"
18 
19 #include "Plugins/Process/Utility/RegisterContextLinux_i386.h"
20 #include "Plugins/Process/Utility/RegisterContextLinux_x86_64.h"
21 #include <cpuid.h>
22 #include <linux/elf.h>
23 
24 // Newer toolchains define __get_cpuid_count in cpuid.h, but some
25 // older-but-still-supported ones (e.g. gcc 5.4.0) don't, so we
26 // define it locally here, following the definition in clang/lib/Headers.
get_cpuid_count(unsigned int __leaf,unsigned int __subleaf,unsigned int * __eax,unsigned int * __ebx,unsigned int * __ecx,unsigned int * __edx)27 static inline int get_cpuid_count(unsigned int __leaf,
28                                   unsigned int __subleaf,
29                                   unsigned int *__eax, unsigned int *__ebx,
30                                   unsigned int *__ecx, unsigned int *__edx)
31 {
32   unsigned int __max_leaf = __get_cpuid_max(__leaf & 0x80000000, nullptr);
33 
34   if (__max_leaf == 0 || __max_leaf < __leaf)
35     return 0;
36 
37   __cpuid_count(__leaf, __subleaf, *__eax, *__ebx, *__ecx, *__edx);
38   return 1;
39 }
40 
41 using namespace lldb_private;
42 using namespace lldb_private::process_linux;
43 
44 // x86 32-bit general purpose registers.
45 static const uint32_t g_gpr_regnums_i386[] = {
46     lldb_eax_i386,      lldb_ebx_i386,    lldb_ecx_i386, lldb_edx_i386,
47     lldb_edi_i386,      lldb_esi_i386,    lldb_ebp_i386, lldb_esp_i386,
48     lldb_eip_i386,      lldb_eflags_i386, lldb_cs_i386,  lldb_fs_i386,
49     lldb_gs_i386,       lldb_ss_i386,     lldb_ds_i386,  lldb_es_i386,
50     lldb_ax_i386,       lldb_bx_i386,     lldb_cx_i386,  lldb_dx_i386,
51     lldb_di_i386,       lldb_si_i386,     lldb_bp_i386,  lldb_sp_i386,
52     lldb_ah_i386,       lldb_bh_i386,     lldb_ch_i386,  lldb_dh_i386,
53     lldb_al_i386,       lldb_bl_i386,     lldb_cl_i386,  lldb_dl_i386,
54     LLDB_INVALID_REGNUM // register sets need to end with this flag
55 };
56 static_assert((sizeof(g_gpr_regnums_i386) / sizeof(g_gpr_regnums_i386[0])) -
57                       1 ==
58                   k_num_gpr_registers_i386,
59               "g_gpr_regnums_i386 has wrong number of register infos");
60 
61 // x86 32-bit floating point registers.
62 static const uint32_t g_fpu_regnums_i386[] = {
63     lldb_fctrl_i386,    lldb_fstat_i386,     lldb_ftag_i386,  lldb_fop_i386,
64     lldb_fiseg_i386,    lldb_fioff_i386,     lldb_foseg_i386, lldb_fooff_i386,
65     lldb_mxcsr_i386,    lldb_mxcsrmask_i386, lldb_st0_i386,   lldb_st1_i386,
66     lldb_st2_i386,      lldb_st3_i386,       lldb_st4_i386,   lldb_st5_i386,
67     lldb_st6_i386,      lldb_st7_i386,       lldb_mm0_i386,   lldb_mm1_i386,
68     lldb_mm2_i386,      lldb_mm3_i386,       lldb_mm4_i386,   lldb_mm5_i386,
69     lldb_mm6_i386,      lldb_mm7_i386,       lldb_xmm0_i386,  lldb_xmm1_i386,
70     lldb_xmm2_i386,     lldb_xmm3_i386,      lldb_xmm4_i386,  lldb_xmm5_i386,
71     lldb_xmm6_i386,     lldb_xmm7_i386,
72     LLDB_INVALID_REGNUM // register sets need to end with this flag
73 };
74 static_assert((sizeof(g_fpu_regnums_i386) / sizeof(g_fpu_regnums_i386[0])) -
75                       1 ==
76                   k_num_fpr_registers_i386,
77               "g_fpu_regnums_i386 has wrong number of register infos");
78 
79 // x86 32-bit AVX registers.
80 static const uint32_t g_avx_regnums_i386[] = {
81     lldb_ymm0_i386,     lldb_ymm1_i386, lldb_ymm2_i386, lldb_ymm3_i386,
82     lldb_ymm4_i386,     lldb_ymm5_i386, lldb_ymm6_i386, lldb_ymm7_i386,
83     LLDB_INVALID_REGNUM // register sets need to end with this flag
84 };
85 static_assert((sizeof(g_avx_regnums_i386) / sizeof(g_avx_regnums_i386[0])) -
86                       1 ==
87                   k_num_avx_registers_i386,
88               " g_avx_regnums_i386 has wrong number of register infos");
89 
90 // x64 32-bit MPX registers.
91 static const uint32_t g_mpx_regnums_i386[] = {
92     lldb_bnd0_i386,     lldb_bnd1_i386, lldb_bnd2_i386, lldb_bnd3_i386,
93     lldb_bndcfgu_i386,  lldb_bndstatus_i386,
94     LLDB_INVALID_REGNUM // register sets need to end with this flag
95 };
96 static_assert((sizeof(g_mpx_regnums_i386) / sizeof(g_mpx_regnums_i386[0])) -
97                       1 ==
98                   k_num_mpx_registers_i386,
99               "g_mpx_regnums_x86_64 has wrong number of register infos");
100 
101 // x86 64-bit general purpose registers.
102 static const uint32_t g_gpr_regnums_x86_64[] = {
103     lldb_rax_x86_64,    lldb_rbx_x86_64,    lldb_rcx_x86_64, lldb_rdx_x86_64,
104     lldb_rdi_x86_64,    lldb_rsi_x86_64,    lldb_rbp_x86_64, lldb_rsp_x86_64,
105     lldb_r8_x86_64,     lldb_r9_x86_64,     lldb_r10_x86_64, lldb_r11_x86_64,
106     lldb_r12_x86_64,    lldb_r13_x86_64,    lldb_r14_x86_64, lldb_r15_x86_64,
107     lldb_rip_x86_64,    lldb_rflags_x86_64, lldb_cs_x86_64,  lldb_fs_x86_64,
108     lldb_gs_x86_64,     lldb_ss_x86_64,     lldb_ds_x86_64,  lldb_es_x86_64,
109     lldb_eax_x86_64,    lldb_ebx_x86_64,    lldb_ecx_x86_64, lldb_edx_x86_64,
110     lldb_edi_x86_64,    lldb_esi_x86_64,    lldb_ebp_x86_64, lldb_esp_x86_64,
111     lldb_r8d_x86_64,  // Low 32 bits or r8
112     lldb_r9d_x86_64,  // Low 32 bits or r9
113     lldb_r10d_x86_64, // Low 32 bits or r10
114     lldb_r11d_x86_64, // Low 32 bits or r11
115     lldb_r12d_x86_64, // Low 32 bits or r12
116     lldb_r13d_x86_64, // Low 32 bits or r13
117     lldb_r14d_x86_64, // Low 32 bits or r14
118     lldb_r15d_x86_64, // Low 32 bits or r15
119     lldb_ax_x86_64,     lldb_bx_x86_64,     lldb_cx_x86_64,  lldb_dx_x86_64,
120     lldb_di_x86_64,     lldb_si_x86_64,     lldb_bp_x86_64,  lldb_sp_x86_64,
121     lldb_r8w_x86_64,  // Low 16 bits or r8
122     lldb_r9w_x86_64,  // Low 16 bits or r9
123     lldb_r10w_x86_64, // Low 16 bits or r10
124     lldb_r11w_x86_64, // Low 16 bits or r11
125     lldb_r12w_x86_64, // Low 16 bits or r12
126     lldb_r13w_x86_64, // Low 16 bits or r13
127     lldb_r14w_x86_64, // Low 16 bits or r14
128     lldb_r15w_x86_64, // Low 16 bits or r15
129     lldb_ah_x86_64,     lldb_bh_x86_64,     lldb_ch_x86_64,  lldb_dh_x86_64,
130     lldb_al_x86_64,     lldb_bl_x86_64,     lldb_cl_x86_64,  lldb_dl_x86_64,
131     lldb_dil_x86_64,    lldb_sil_x86_64,    lldb_bpl_x86_64, lldb_spl_x86_64,
132     lldb_r8l_x86_64,    // Low 8 bits or r8
133     lldb_r9l_x86_64,    // Low 8 bits or r9
134     lldb_r10l_x86_64,   // Low 8 bits or r10
135     lldb_r11l_x86_64,   // Low 8 bits or r11
136     lldb_r12l_x86_64,   // Low 8 bits or r12
137     lldb_r13l_x86_64,   // Low 8 bits or r13
138     lldb_r14l_x86_64,   // Low 8 bits or r14
139     lldb_r15l_x86_64,   // Low 8 bits or r15
140     LLDB_INVALID_REGNUM // register sets need to end with this flag
141 };
142 static_assert((sizeof(g_gpr_regnums_x86_64) / sizeof(g_gpr_regnums_x86_64[0])) -
143                       1 ==
144                   k_num_gpr_registers_x86_64,
145               "g_gpr_regnums_x86_64 has wrong number of register infos");
146 
147 // x86 64-bit floating point registers.
148 static const uint32_t g_fpu_regnums_x86_64[] = {
149     lldb_fctrl_x86_64,  lldb_fstat_x86_64, lldb_ftag_x86_64,
150     lldb_fop_x86_64,    lldb_fiseg_x86_64, lldb_fioff_x86_64,
151     lldb_fip_x86_64,    lldb_foseg_x86_64, lldb_fooff_x86_64,
152     lldb_fdp_x86_64,    lldb_mxcsr_x86_64, lldb_mxcsrmask_x86_64,
153     lldb_st0_x86_64,    lldb_st1_x86_64,   lldb_st2_x86_64,
154     lldb_st3_x86_64,    lldb_st4_x86_64,   lldb_st5_x86_64,
155     lldb_st6_x86_64,    lldb_st7_x86_64,   lldb_mm0_x86_64,
156     lldb_mm1_x86_64,    lldb_mm2_x86_64,   lldb_mm3_x86_64,
157     lldb_mm4_x86_64,    lldb_mm5_x86_64,   lldb_mm6_x86_64,
158     lldb_mm7_x86_64,    lldb_xmm0_x86_64,  lldb_xmm1_x86_64,
159     lldb_xmm2_x86_64,   lldb_xmm3_x86_64,  lldb_xmm4_x86_64,
160     lldb_xmm5_x86_64,   lldb_xmm6_x86_64,  lldb_xmm7_x86_64,
161     lldb_xmm8_x86_64,   lldb_xmm9_x86_64,  lldb_xmm10_x86_64,
162     lldb_xmm11_x86_64,  lldb_xmm12_x86_64, lldb_xmm13_x86_64,
163     lldb_xmm14_x86_64,  lldb_xmm15_x86_64,
164     LLDB_INVALID_REGNUM // register sets need to end with this flag
165 };
166 static_assert((sizeof(g_fpu_regnums_x86_64) / sizeof(g_fpu_regnums_x86_64[0])) -
167                       1 ==
168                   k_num_fpr_registers_x86_64,
169               "g_fpu_regnums_x86_64 has wrong number of register infos");
170 
171 // x86 64-bit AVX registers.
172 static const uint32_t g_avx_regnums_x86_64[] = {
173     lldb_ymm0_x86_64,   lldb_ymm1_x86_64,  lldb_ymm2_x86_64,  lldb_ymm3_x86_64,
174     lldb_ymm4_x86_64,   lldb_ymm5_x86_64,  lldb_ymm6_x86_64,  lldb_ymm7_x86_64,
175     lldb_ymm8_x86_64,   lldb_ymm9_x86_64,  lldb_ymm10_x86_64, lldb_ymm11_x86_64,
176     lldb_ymm12_x86_64,  lldb_ymm13_x86_64, lldb_ymm14_x86_64, lldb_ymm15_x86_64,
177     LLDB_INVALID_REGNUM // register sets need to end with this flag
178 };
179 static_assert((sizeof(g_avx_regnums_x86_64) / sizeof(g_avx_regnums_x86_64[0])) -
180                       1 ==
181                   k_num_avx_registers_x86_64,
182               "g_avx_regnums_x86_64 has wrong number of register infos");
183 
184 // x86 64-bit MPX registers.
185 static const uint32_t g_mpx_regnums_x86_64[] = {
186     lldb_bnd0_x86_64,    lldb_bnd1_x86_64,    lldb_bnd2_x86_64,
187     lldb_bnd3_x86_64,    lldb_bndcfgu_x86_64, lldb_bndstatus_x86_64,
188     LLDB_INVALID_REGNUM // register sets need to end with this flag
189 };
190 static_assert((sizeof(g_mpx_regnums_x86_64) / sizeof(g_mpx_regnums_x86_64[0])) -
191                       1 ==
192                   k_num_mpx_registers_x86_64,
193               "g_mpx_regnums_x86_64 has wrong number of register infos");
194 
195 // Number of register sets provided by this context.
196 constexpr unsigned k_num_extended_register_sets = 2, k_num_register_sets = 4;
197 
198 // Register sets for x86 32-bit.
199 static const RegisterSet g_reg_sets_i386[k_num_register_sets] = {
200     {"General Purpose Registers", "gpr", k_num_gpr_registers_i386,
201      g_gpr_regnums_i386},
202     {"Floating Point Registers", "fpu", k_num_fpr_registers_i386,
203      g_fpu_regnums_i386},
204     {"Advanced Vector Extensions", "avx", k_num_avx_registers_i386,
205      g_avx_regnums_i386},
206     { "Memory Protection Extensions", "mpx", k_num_mpx_registers_i386,
207      g_mpx_regnums_i386}};
208 
209 // Register sets for x86 64-bit.
210 static const RegisterSet g_reg_sets_x86_64[k_num_register_sets] = {
211     {"General Purpose Registers", "gpr", k_num_gpr_registers_x86_64,
212      g_gpr_regnums_x86_64},
213     {"Floating Point Registers", "fpu", k_num_fpr_registers_x86_64,
214      g_fpu_regnums_x86_64},
215     {"Advanced Vector Extensions", "avx", k_num_avx_registers_x86_64,
216      g_avx_regnums_x86_64},
217     { "Memory Protection Extensions", "mpx", k_num_mpx_registers_x86_64,
218      g_mpx_regnums_x86_64}};
219 
220 #define REG_CONTEXT_SIZE (GetRegisterInfoInterface().GetGPRSize() + sizeof(FPR))
221 
222 // Required ptrace defines.
223 
224 // Support ptrace extensions even when compiled without required kernel support
225 #ifndef NT_X86_XSTATE
226 #define NT_X86_XSTATE 0x202
227 #endif
228 #ifndef NT_PRXFPREG
229 #define NT_PRXFPREG 0x46e62b7f
230 #endif
231 
232 // On x86_64 NT_PRFPREG is used to access the FXSAVE area. On i386, we need to
233 // use NT_PRXFPREG.
fxsr_regset(const ArchSpec & arch)234 static inline unsigned int fxsr_regset(const ArchSpec &arch) {
235   return arch.GetAddressByteSize() == 8 ? NT_PRFPREG : NT_PRXFPREG;
236 }
237 
238 // Required MPX define.
239 
240 // Support MPX extensions also if compiled with compiler without MPX support.
241 #ifndef bit_MPX
242 #define bit_MPX 0x4000
243 #endif
244 
245 // XCR0 extended register sets masks.
246 #define mask_XSTATE_AVX (1ULL << 2)
247 #define mask_XSTATE_BNDREGS (1ULL << 3)
248 #define mask_XSTATE_BNDCFG (1ULL << 4)
249 #define mask_XSTATE_MPX (mask_XSTATE_BNDREGS | mask_XSTATE_BNDCFG)
250 
251 std::unique_ptr<NativeRegisterContextLinux>
CreateHostNativeRegisterContextLinux(const ArchSpec & target_arch,NativeThreadProtocol & native_thread)252 NativeRegisterContextLinux::CreateHostNativeRegisterContextLinux(
253     const ArchSpec &target_arch, NativeThreadProtocol &native_thread) {
254   return std::unique_ptr<NativeRegisterContextLinux>(
255       new NativeRegisterContextLinux_x86_64(target_arch, native_thread));
256 }
257 
258 // NativeRegisterContextLinux_x86_64 members.
259 
260 static RegisterInfoInterface *
CreateRegisterInfoInterface(const ArchSpec & target_arch)261 CreateRegisterInfoInterface(const ArchSpec &target_arch) {
262   if (HostInfo::GetArchitecture().GetAddressByteSize() == 4) {
263     // 32-bit hosts run with a RegisterContextLinux_i386 context.
264     return new RegisterContextLinux_i386(target_arch);
265   } else {
266     assert((HostInfo::GetArchitecture().GetAddressByteSize() == 8) &&
267            "Register setting path assumes this is a 64-bit host");
268     // X86_64 hosts know how to work with 64-bit and 32-bit EXEs using the
269     // x86_64 register context.
270     return new RegisterContextLinux_x86_64(target_arch);
271   }
272 }
273 
274 // Return the size of the XSTATE area supported on this cpu. It is necessary to
275 // allocate the full size of the area even if we do not use/recognise all of it
276 // because ptrace(PTRACE_SETREGSET, NT_X86_XSTATE) will refuse to write to it if
277 // we do not pass it a buffer of sufficient size. The size is always at least
278 // sizeof(FPR) so that the allocated buffer can be safely cast to FPR*.
GetXSTATESize()279 static std::size_t GetXSTATESize() {
280   unsigned int eax, ebx, ecx, edx;
281   // First check whether the XSTATE are is supported at all.
282   if (!__get_cpuid(1, &eax, &ebx, &ecx, &edx) || !(ecx & bit_XSAVE))
283     return sizeof(FPR);
284 
285   // Then fetch the maximum size of the area.
286   if (!get_cpuid_count(0x0d, 0, &eax, &ebx, &ecx, &edx))
287     return sizeof(FPR);
288   return std::max<std::size_t>(ecx, sizeof(FPR));
289 }
290 
NativeRegisterContextLinux_x86_64(const ArchSpec & target_arch,NativeThreadProtocol & native_thread)291 NativeRegisterContextLinux_x86_64::NativeRegisterContextLinux_x86_64(
292     const ArchSpec &target_arch, NativeThreadProtocol &native_thread)
293     : NativeRegisterContextRegisterInfo(
294           native_thread, CreateRegisterInfoInterface(target_arch)),
295       m_xstate_type(XStateType::Invalid), m_ymm_set(), m_mpx_set(),
296       m_reg_info(), m_gpr_x86_64() {
297   // Set up data about ranges of valid registers.
298   switch (target_arch.GetMachine()) {
299   case llvm::Triple::x86:
300     m_reg_info.num_registers = k_num_registers_i386;
301     m_reg_info.num_gpr_registers = k_num_gpr_registers_i386;
302     m_reg_info.num_fpr_registers = k_num_fpr_registers_i386;
303     m_reg_info.num_avx_registers = k_num_avx_registers_i386;
304     m_reg_info.num_mpx_registers = k_num_mpx_registers_i386;
305     m_reg_info.last_gpr = k_last_gpr_i386;
306     m_reg_info.first_fpr = k_first_fpr_i386;
307     m_reg_info.last_fpr = k_last_fpr_i386;
308     m_reg_info.first_st = lldb_st0_i386;
309     m_reg_info.last_st = lldb_st7_i386;
310     m_reg_info.first_mm = lldb_mm0_i386;
311     m_reg_info.last_mm = lldb_mm7_i386;
312     m_reg_info.first_xmm = lldb_xmm0_i386;
313     m_reg_info.last_xmm = lldb_xmm7_i386;
314     m_reg_info.first_ymm = lldb_ymm0_i386;
315     m_reg_info.last_ymm = lldb_ymm7_i386;
316     m_reg_info.first_mpxr = lldb_bnd0_i386;
317     m_reg_info.last_mpxr = lldb_bnd3_i386;
318     m_reg_info.first_mpxc = lldb_bndcfgu_i386;
319     m_reg_info.last_mpxc = lldb_bndstatus_i386;
320     m_reg_info.first_dr = lldb_dr0_i386;
321     m_reg_info.last_dr = lldb_dr7_i386;
322     m_reg_info.gpr_flags = lldb_eflags_i386;
323     break;
324   case llvm::Triple::x86_64:
325     m_reg_info.num_registers = k_num_registers_x86_64;
326     m_reg_info.num_gpr_registers = k_num_gpr_registers_x86_64;
327     m_reg_info.num_fpr_registers = k_num_fpr_registers_x86_64;
328     m_reg_info.num_avx_registers = k_num_avx_registers_x86_64;
329     m_reg_info.num_mpx_registers = k_num_mpx_registers_x86_64;
330     m_reg_info.last_gpr = k_last_gpr_x86_64;
331     m_reg_info.first_fpr = k_first_fpr_x86_64;
332     m_reg_info.last_fpr = k_last_fpr_x86_64;
333     m_reg_info.first_st = lldb_st0_x86_64;
334     m_reg_info.last_st = lldb_st7_x86_64;
335     m_reg_info.first_mm = lldb_mm0_x86_64;
336     m_reg_info.last_mm = lldb_mm7_x86_64;
337     m_reg_info.first_xmm = lldb_xmm0_x86_64;
338     m_reg_info.last_xmm = lldb_xmm15_x86_64;
339     m_reg_info.first_ymm = lldb_ymm0_x86_64;
340     m_reg_info.last_ymm = lldb_ymm15_x86_64;
341     m_reg_info.first_mpxr = lldb_bnd0_x86_64;
342     m_reg_info.last_mpxr = lldb_bnd3_x86_64;
343     m_reg_info.first_mpxc = lldb_bndcfgu_x86_64;
344     m_reg_info.last_mpxc = lldb_bndstatus_x86_64;
345     m_reg_info.first_dr = lldb_dr0_x86_64;
346     m_reg_info.last_dr = lldb_dr7_x86_64;
347     m_reg_info.gpr_flags = lldb_rflags_x86_64;
348     break;
349   default:
350     assert(false && "Unhandled target architecture.");
351     break;
352   }
353 
354   std::size_t xstate_size = GetXSTATESize();
355   m_xstate.reset(static_cast<FPR *>(std::malloc(xstate_size)));
356   m_iovec.iov_base = m_xstate.get();
357   m_iovec.iov_len = xstate_size;
358 
359   // Clear out the FPR state.
360   ::memset(m_xstate.get(), 0, xstate_size);
361 
362   // Store byte offset of fctrl (i.e. first register of FPR)
363   const RegisterInfo *reg_info_fctrl = GetRegisterInfoByName("fctrl");
364   m_fctrl_offset_in_userarea = reg_info_fctrl->byte_offset;
365 }
366 
367 // CONSIDER after local and llgs debugging are merged, register set support can
368 // be moved into a base x86-64 class with IsRegisterSetAvailable made virtual.
GetRegisterSetCount() const369 uint32_t NativeRegisterContextLinux_x86_64::GetRegisterSetCount() const {
370   uint32_t sets = 0;
371   for (uint32_t set_index = 0; set_index < k_num_register_sets; ++set_index) {
372     if (IsRegisterSetAvailable(set_index))
373       ++sets;
374   }
375 
376   return sets;
377 }
378 
GetUserRegisterCount() const379 uint32_t NativeRegisterContextLinux_x86_64::GetUserRegisterCount() const {
380   uint32_t count = 0;
381   for (uint32_t set_index = 0; set_index < k_num_register_sets; ++set_index) {
382     const RegisterSet *set = GetRegisterSet(set_index);
383     if (set)
384       count += set->num_registers;
385   }
386   return count;
387 }
388 
389 const RegisterSet *
GetRegisterSet(uint32_t set_index) const390 NativeRegisterContextLinux_x86_64::GetRegisterSet(uint32_t set_index) const {
391   if (!IsRegisterSetAvailable(set_index))
392     return nullptr;
393 
394   switch (GetRegisterInfoInterface().GetTargetArchitecture().GetMachine()) {
395   case llvm::Triple::x86:
396     return &g_reg_sets_i386[set_index];
397   case llvm::Triple::x86_64:
398     return &g_reg_sets_x86_64[set_index];
399   default:
400     assert(false && "Unhandled target architecture.");
401     return nullptr;
402   }
403 
404   return nullptr;
405 }
406 
407 Status
ReadRegister(const RegisterInfo * reg_info,RegisterValue & reg_value)408 NativeRegisterContextLinux_x86_64::ReadRegister(const RegisterInfo *reg_info,
409                                                 RegisterValue &reg_value) {
410   Status error;
411 
412   if (!reg_info) {
413     error.SetErrorString("reg_info NULL");
414     return error;
415   }
416 
417   const uint32_t reg = reg_info->kinds[lldb::eRegisterKindLLDB];
418   if (reg == LLDB_INVALID_REGNUM) {
419     // This is likely an internal register for lldb use only and should not be
420     // directly queried.
421     error.SetErrorStringWithFormat("register \"%s\" is an internal-only lldb "
422                                    "register, cannot read directly",
423                                    reg_info->name);
424     return error;
425   }
426 
427   if (IsFPR(reg) || IsAVX(reg) || IsMPX(reg)) {
428     error = ReadFPR();
429     if (error.Fail())
430       return error;
431   } else {
432     uint32_t full_reg = reg;
433     bool is_subreg = reg_info->invalidate_regs &&
434                      (reg_info->invalidate_regs[0] != LLDB_INVALID_REGNUM);
435 
436     if (is_subreg) {
437       // Read the full aligned 64-bit register.
438       full_reg = reg_info->invalidate_regs[0];
439     }
440 
441     error = ReadRegisterRaw(full_reg, reg_value);
442 
443     if (error.Success()) {
444       // If our read was not aligned (for ah,bh,ch,dh), shift our returned
445       // value one byte to the right.
446       if (is_subreg && (reg_info->byte_offset & 0x1))
447         reg_value.SetUInt64(reg_value.GetAsUInt64() >> 8);
448 
449       // If our return byte size was greater than the return value reg size,
450       // then use the type specified by reg_info rather than the uint64_t
451       // default
452       if (reg_value.GetByteSize() > reg_info->byte_size)
453         reg_value.SetType(reg_info);
454     }
455     return error;
456   }
457 
458   if (reg_info->encoding == lldb::eEncodingVector) {
459     lldb::ByteOrder byte_order = GetByteOrder();
460 
461     if (byte_order != lldb::eByteOrderInvalid) {
462       if (reg >= m_reg_info.first_st && reg <= m_reg_info.last_st)
463         reg_value.SetBytes(
464             m_xstate->fxsave.stmm[reg - m_reg_info.first_st].bytes,
465             reg_info->byte_size, byte_order);
466       if (reg >= m_reg_info.first_mm && reg <= m_reg_info.last_mm)
467         reg_value.SetBytes(
468             m_xstate->fxsave.stmm[reg - m_reg_info.first_mm].bytes,
469             reg_info->byte_size, byte_order);
470       if (reg >= m_reg_info.first_xmm && reg <= m_reg_info.last_xmm)
471         reg_value.SetBytes(
472             m_xstate->fxsave.xmm[reg - m_reg_info.first_xmm].bytes,
473             reg_info->byte_size, byte_order);
474       if (reg >= m_reg_info.first_ymm && reg <= m_reg_info.last_ymm) {
475         // Concatenate ymm using the register halves in xmm.bytes and
476         // ymmh.bytes
477         if (CopyXSTATEtoYMM(reg, byte_order))
478           reg_value.SetBytes(m_ymm_set.ymm[reg - m_reg_info.first_ymm].bytes,
479                              reg_info->byte_size, byte_order);
480         else {
481           error.SetErrorString("failed to copy ymm register value");
482           return error;
483         }
484       }
485       if (reg >= m_reg_info.first_mpxr && reg <= m_reg_info.last_mpxr) {
486         if (CopyXSTATEtoMPX(reg))
487           reg_value.SetBytes(m_mpx_set.mpxr[reg - m_reg_info.first_mpxr].bytes,
488                              reg_info->byte_size, byte_order);
489         else {
490           error.SetErrorString("failed to copy mpx register value");
491           return error;
492         }
493       }
494       if (reg >= m_reg_info.first_mpxc && reg <= m_reg_info.last_mpxc) {
495         if (CopyXSTATEtoMPX(reg))
496           reg_value.SetBytes(m_mpx_set.mpxc[reg - m_reg_info.first_mpxc].bytes,
497                              reg_info->byte_size, byte_order);
498         else {
499           error.SetErrorString("failed to copy mpx register value");
500           return error;
501         }
502       }
503 
504       if (reg_value.GetType() != RegisterValue::eTypeBytes)
505         error.SetErrorString(
506             "write failed - type was expected to be RegisterValue::eTypeBytes");
507 
508       return error;
509     }
510 
511     error.SetErrorString("byte order is invalid");
512     return error;
513   }
514 
515   // Get pointer to m_xstate->fxsave variable and set the data from it.
516 
517   // Byte offsets of all registers are calculated wrt 'UserArea' structure.
518   // However, ReadFPR() reads fpu registers {using ptrace(PTRACE_GETFPREGS,..)}
519   // and stores them in 'm_fpr' (of type FPR structure). To extract values of
520   // fpu registers, m_fpr should be read at byte offsets calculated wrt to FPR
521   // structure.
522 
523   // Since, FPR structure is also one of the member of UserArea structure.
524   // byte_offset(fpu wrt FPR) = byte_offset(fpu wrt UserArea) -
525   // byte_offset(fctrl wrt UserArea)
526   assert((reg_info->byte_offset - m_fctrl_offset_in_userarea) < sizeof(FPR));
527   uint8_t *src = (uint8_t *)m_xstate.get() + reg_info->byte_offset -
528                  m_fctrl_offset_in_userarea;
529 
530   if (src == reinterpret_cast<uint8_t *>(&m_xstate->fxsave.ftag)) {
531     reg_value.SetUInt16(AbridgedToFullTagWord(
532         m_xstate->fxsave.ftag, m_xstate->fxsave.fstat, m_xstate->fxsave.stmm));
533     return error;
534   }
535 
536   switch (reg_info->byte_size) {
537   case 1:
538     reg_value.SetUInt8(*(uint8_t *)src);
539     break;
540   case 2:
541     reg_value.SetUInt16(*(uint16_t *)src);
542     break;
543   case 4:
544     reg_value.SetUInt32(*(uint32_t *)src);
545     break;
546   case 8:
547     reg_value.SetUInt64(*(uint64_t *)src);
548     break;
549   default:
550     assert(false && "Unhandled data size.");
551     error.SetErrorStringWithFormat("unhandled byte size: %" PRIu32,
552                                    reg_info->byte_size);
553     break;
554   }
555 
556   return error;
557 }
558 
UpdateXSTATEforWrite(uint32_t reg_index)559 void NativeRegisterContextLinux_x86_64::UpdateXSTATEforWrite(
560     uint32_t reg_index) {
561   XSAVE_HDR::XFeature &xstate_bv = m_xstate->xsave.header.xstate_bv;
562   if (IsFPR(reg_index)) {
563     // IsFPR considers both %st and %xmm registers as floating point, but these
564     // map to two features. Set both flags, just in case.
565     xstate_bv |= XSAVE_HDR::XFeature::FP | XSAVE_HDR::XFeature::SSE;
566   } else if (IsAVX(reg_index)) {
567     // Lower bytes of some %ymm registers are shared with %xmm registers.
568     xstate_bv |= XSAVE_HDR::XFeature::YMM | XSAVE_HDR::XFeature::SSE;
569   } else if (IsMPX(reg_index)) {
570     // MPX registers map to two XSAVE features.
571     xstate_bv |= XSAVE_HDR::XFeature::BNDREGS | XSAVE_HDR::XFeature::BNDCSR;
572   }
573 }
574 
WriteRegister(const RegisterInfo * reg_info,const RegisterValue & reg_value)575 Status NativeRegisterContextLinux_x86_64::WriteRegister(
576     const RegisterInfo *reg_info, const RegisterValue &reg_value) {
577   assert(reg_info && "reg_info is null");
578 
579   const uint32_t reg_index = reg_info->kinds[lldb::eRegisterKindLLDB];
580   if (reg_index == LLDB_INVALID_REGNUM)
581     return Status("no lldb regnum for %s", reg_info && reg_info->name
582                                                ? reg_info->name
583                                                : "<unknown register>");
584 
585   UpdateXSTATEforWrite(reg_index);
586 
587   if (IsGPR(reg_index) || IsDR(reg_index))
588     return WriteRegisterRaw(reg_index, reg_value);
589 
590   if (IsFPR(reg_index) || IsAVX(reg_index) || IsMPX(reg_index)) {
591     if (reg_info->encoding == lldb::eEncodingVector) {
592       if (reg_index >= m_reg_info.first_st && reg_index <= m_reg_info.last_st)
593         ::memcpy(m_xstate->fxsave.stmm[reg_index - m_reg_info.first_st].bytes,
594                  reg_value.GetBytes(), reg_value.GetByteSize());
595 
596       if (reg_index >= m_reg_info.first_mm && reg_index <= m_reg_info.last_mm)
597         ::memcpy(m_xstate->fxsave.stmm[reg_index - m_reg_info.first_mm].bytes,
598                  reg_value.GetBytes(), reg_value.GetByteSize());
599 
600       if (reg_index >= m_reg_info.first_xmm && reg_index <= m_reg_info.last_xmm)
601         ::memcpy(m_xstate->fxsave.xmm[reg_index - m_reg_info.first_xmm].bytes,
602                  reg_value.GetBytes(), reg_value.GetByteSize());
603 
604       if (reg_index >= m_reg_info.first_ymm &&
605           reg_index <= m_reg_info.last_ymm) {
606         // Store ymm register content, and split into the register halves in
607         // xmm.bytes and ymmh.bytes
608         ::memcpy(m_ymm_set.ymm[reg_index - m_reg_info.first_ymm].bytes,
609                  reg_value.GetBytes(), reg_value.GetByteSize());
610         if (!CopyYMMtoXSTATE(reg_index, GetByteOrder()))
611           return Status("CopyYMMtoXSTATE() failed");
612       }
613 
614       if (reg_index >= m_reg_info.first_mpxr &&
615           reg_index <= m_reg_info.last_mpxr) {
616         ::memcpy(m_mpx_set.mpxr[reg_index - m_reg_info.first_mpxr].bytes,
617                  reg_value.GetBytes(), reg_value.GetByteSize());
618         if (!CopyMPXtoXSTATE(reg_index))
619           return Status("CopyMPXtoXSTATE() failed");
620       }
621 
622       if (reg_index >= m_reg_info.first_mpxc &&
623           reg_index <= m_reg_info.last_mpxc) {
624         ::memcpy(m_mpx_set.mpxc[reg_index - m_reg_info.first_mpxc].bytes,
625                  reg_value.GetBytes(), reg_value.GetByteSize());
626         if (!CopyMPXtoXSTATE(reg_index))
627           return Status("CopyMPXtoXSTATE() failed");
628       }
629     } else {
630       // Get pointer to m_xstate->fxsave variable and set the data to it.
631 
632       // Byte offsets of all registers are calculated wrt 'UserArea' structure.
633       // However, WriteFPR() takes m_fpr (of type FPR structure) and writes
634       // only fpu registers using ptrace(PTRACE_SETFPREGS,..) API. Hence fpu
635       // registers should be written in m_fpr at byte offsets calculated wrt
636       // FPR structure.
637 
638       // Since, FPR structure is also one of the member of UserArea structure.
639       // byte_offset(fpu wrt FPR) = byte_offset(fpu wrt UserArea) -
640       // byte_offset(fctrl wrt UserArea)
641       assert((reg_info->byte_offset - m_fctrl_offset_in_userarea) <
642              sizeof(FPR));
643       uint8_t *dst = (uint8_t *)m_xstate.get() + reg_info->byte_offset -
644                      m_fctrl_offset_in_userarea;
645 
646       if (dst == reinterpret_cast<uint8_t *>(&m_xstate->fxsave.ftag))
647         m_xstate->fxsave.ftag = FullToAbridgedTagWord(reg_value.GetAsUInt16());
648       else {
649         switch (reg_info->byte_size) {
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 Status("unhandled register data size %" PRIu32,
665                         reg_info->byte_size);
666         }
667       }
668     }
669 
670     Status error = WriteFPR();
671     if (error.Fail())
672       return error;
673 
674     if (IsAVX(reg_index)) {
675       if (!CopyYMMtoXSTATE(reg_index, GetByteOrder()))
676         return Status("CopyYMMtoXSTATE() failed");
677     }
678 
679     if (IsMPX(reg_index)) {
680       if (!CopyMPXtoXSTATE(reg_index))
681         return Status("CopyMPXtoXSTATE() failed");
682     }
683     return Status();
684   }
685   return Status("failed - register wasn't recognized to be a GPR or an FPR, "
686                 "write strategy unknown");
687 }
688 
ReadAllRegisterValues(lldb::DataBufferSP & data_sp)689 Status NativeRegisterContextLinux_x86_64::ReadAllRegisterValues(
690     lldb::DataBufferSP &data_sp) {
691   Status error;
692 
693   data_sp.reset(new DataBufferHeap(REG_CONTEXT_SIZE, 0));
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   ::memcpy(dst, &m_gpr_x86_64, GetRegisterInfoInterface().GetGPRSize());
704   dst += GetRegisterInfoInterface().GetGPRSize();
705   if (m_xstate_type == XStateType::FXSAVE)
706     ::memcpy(dst, &m_xstate->fxsave, sizeof(m_xstate->fxsave));
707   else if (m_xstate_type == XStateType::XSAVE) {
708     lldb::ByteOrder byte_order = GetByteOrder();
709 
710     if (IsCPUFeatureAvailable(RegSet::avx)) {
711       // Assemble the YMM register content from the register halves.
712       for (uint32_t reg = m_reg_info.first_ymm; reg <= m_reg_info.last_ymm;
713            ++reg) {
714         if (!CopyXSTATEtoYMM(reg, byte_order)) {
715           error.SetErrorStringWithFormat(
716               "NativeRegisterContextLinux_x86_64::%s "
717               "CopyXSTATEtoYMM() failed for reg num "
718               "%" PRIu32,
719               __FUNCTION__, reg);
720           return error;
721         }
722       }
723     }
724 
725     if (IsCPUFeatureAvailable(RegSet::mpx)) {
726       for (uint32_t reg = m_reg_info.first_mpxr; reg <= m_reg_info.last_mpxc;
727            ++reg) {
728         if (!CopyXSTATEtoMPX(reg)) {
729           error.SetErrorStringWithFormat(
730               "NativeRegisterContextLinux_x86_64::%s "
731               "CopyXSTATEtoMPX() failed for reg num "
732               "%" PRIu32,
733               __FUNCTION__, reg);
734           return error;
735         }
736       }
737     }
738     // Copy the extended register state including the assembled ymm registers.
739     ::memcpy(dst, m_xstate.get(), sizeof(FPR));
740   } else {
741     assert(false && "how do we save the floating point registers?");
742     error.SetErrorString("unsure how to save the floating point registers");
743   }
744   /** The following code is specific to Linux x86 based architectures,
745    *  where the register orig_eax (32 bit)/orig_rax (64 bit) is set to
746    *  -1 to solve the bug 23659, such a setting prevents the automatic
747    *  decrement of the instruction pointer which was causing the SIGILL
748    *  exception.
749    * **/
750 
751   RegisterValue value((uint64_t)-1);
752   const RegisterInfo *reg_info =
753       GetRegisterInfoInterface().GetDynamicRegisterInfo("orig_eax");
754   if (reg_info == nullptr)
755     reg_info = GetRegisterInfoInterface().GetDynamicRegisterInfo("orig_rax");
756 
757   if (reg_info != nullptr)
758     return DoWriteRegisterValue(reg_info->byte_offset, reg_info->name, value);
759 
760   return error;
761 }
762 
WriteAllRegisterValues(const lldb::DataBufferSP & data_sp)763 Status NativeRegisterContextLinux_x86_64::WriteAllRegisterValues(
764     const lldb::DataBufferSP &data_sp) {
765   Status error;
766 
767   if (!data_sp) {
768     error.SetErrorStringWithFormat(
769         "NativeRegisterContextLinux_x86_64::%s invalid data_sp provided",
770         __FUNCTION__);
771     return error;
772   }
773 
774   if (data_sp->GetByteSize() != REG_CONTEXT_SIZE) {
775     error.SetErrorStringWithFormatv(
776         "data_sp contained mismatched data size, expected {0}, actual {1}",
777         REG_CONTEXT_SIZE, data_sp->GetByteSize());
778     return error;
779   }
780 
781   uint8_t *src = data_sp->GetBytes();
782   if (src == nullptr) {
783     error.SetErrorStringWithFormat("NativeRegisterContextLinux_x86_64::%s "
784                                    "DataBuffer::GetBytes() returned a null "
785                                    "pointer",
786                                    __FUNCTION__);
787     return error;
788   }
789   ::memcpy(&m_gpr_x86_64, src, GetRegisterInfoInterface().GetGPRSize());
790 
791   error = WriteGPR();
792   if (error.Fail())
793     return error;
794 
795   src += GetRegisterInfoInterface().GetGPRSize();
796   if (m_xstate_type == XStateType::FXSAVE)
797     ::memcpy(&m_xstate->fxsave, src, sizeof(m_xstate->fxsave));
798   else if (m_xstate_type == XStateType::XSAVE)
799     ::memcpy(&m_xstate->xsave, src, sizeof(m_xstate->xsave));
800 
801   error = WriteFPR();
802   if (error.Fail())
803     return error;
804 
805   if (m_xstate_type == XStateType::XSAVE) {
806     lldb::ByteOrder byte_order = GetByteOrder();
807 
808     if (IsCPUFeatureAvailable(RegSet::avx)) {
809       // Parse the YMM register content from the register halves.
810       for (uint32_t reg = m_reg_info.first_ymm; reg <= m_reg_info.last_ymm;
811            ++reg) {
812         if (!CopyYMMtoXSTATE(reg, byte_order)) {
813           error.SetErrorStringWithFormat(
814               "NativeRegisterContextLinux_x86_64::%s "
815               "CopyYMMtoXSTATE() failed for reg num "
816               "%" PRIu32,
817               __FUNCTION__, reg);
818           return error;
819         }
820       }
821     }
822 
823     if (IsCPUFeatureAvailable(RegSet::mpx)) {
824       for (uint32_t reg = m_reg_info.first_mpxr; reg <= m_reg_info.last_mpxc;
825            ++reg) {
826         if (!CopyMPXtoXSTATE(reg)) {
827           error.SetErrorStringWithFormat(
828               "NativeRegisterContextLinux_x86_64::%s "
829               "CopyMPXtoXSTATE() failed for reg num "
830               "%" PRIu32,
831               __FUNCTION__, reg);
832           return error;
833         }
834       }
835     }
836   }
837 
838   return error;
839 }
840 
IsCPUFeatureAvailable(RegSet feature_code) const841 bool NativeRegisterContextLinux_x86_64::IsCPUFeatureAvailable(
842     RegSet feature_code) const {
843   if (m_xstate_type == XStateType::Invalid) {
844     if (const_cast<NativeRegisterContextLinux_x86_64 *>(this)->ReadFPR().Fail())
845       return false;
846   }
847   switch (feature_code) {
848   case RegSet::gpr:
849   case RegSet::fpu:
850     return true;
851   case RegSet::avx: // Check if CPU has AVX and if there is kernel support, by
852                     // reading in the XCR0 area of XSAVE.
853     if ((m_xstate->xsave.i387.xcr0 & mask_XSTATE_AVX) == mask_XSTATE_AVX)
854       return true;
855      break;
856   case RegSet::mpx: // Check if CPU has MPX and if there is kernel support, by
857                     // reading in the XCR0 area of XSAVE.
858     if ((m_xstate->xsave.i387.xcr0 & mask_XSTATE_MPX) == mask_XSTATE_MPX)
859       return true;
860     break;
861   }
862   return false;
863 }
864 
IsRegisterSetAvailable(uint32_t set_index) const865 bool NativeRegisterContextLinux_x86_64::IsRegisterSetAvailable(
866     uint32_t set_index) const {
867   uint32_t num_sets = k_num_register_sets - k_num_extended_register_sets;
868 
869   switch (static_cast<RegSet>(set_index)) {
870   case RegSet::gpr:
871   case RegSet::fpu:
872     return (set_index < num_sets);
873   case RegSet::avx:
874     return IsCPUFeatureAvailable(RegSet::avx);
875   case RegSet::mpx:
876     return IsCPUFeatureAvailable(RegSet::mpx);
877   }
878   return false;
879 }
880 
IsGPR(uint32_t reg_index) const881 bool NativeRegisterContextLinux_x86_64::IsGPR(uint32_t reg_index) const {
882   // GPRs come first.
883   return reg_index <= m_reg_info.last_gpr;
884 }
885 
IsFPR(uint32_t reg_index) const886 bool NativeRegisterContextLinux_x86_64::IsFPR(uint32_t reg_index) const {
887   return (m_reg_info.first_fpr <= reg_index &&
888           reg_index <= m_reg_info.last_fpr);
889 }
890 
IsDR(uint32_t reg_index) const891 bool NativeRegisterContextLinux_x86_64::IsDR(uint32_t reg_index) const {
892   return (m_reg_info.first_dr <= reg_index &&
893           reg_index <= m_reg_info.last_dr);
894 }
895 
WriteFPR()896 Status NativeRegisterContextLinux_x86_64::WriteFPR() {
897   switch (m_xstate_type) {
898   case XStateType::FXSAVE:
899     return WriteRegisterSet(
900         &m_iovec, sizeof(m_xstate->fxsave),
901         fxsr_regset(GetRegisterInfoInterface().GetTargetArchitecture()));
902   case XStateType::XSAVE:
903     return WriteRegisterSet(&m_iovec, sizeof(m_xstate->xsave), NT_X86_XSTATE);
904   default:
905     return Status("Unrecognized FPR type.");
906   }
907 }
908 
IsAVX(uint32_t reg_index) const909 bool NativeRegisterContextLinux_x86_64::IsAVX(uint32_t reg_index) const {
910   if (!IsCPUFeatureAvailable(RegSet::avx))
911     return false;
912   return (m_reg_info.first_ymm <= reg_index &&
913           reg_index <= m_reg_info.last_ymm);
914 }
915 
CopyXSTATEtoYMM(uint32_t reg_index,lldb::ByteOrder byte_order)916 bool NativeRegisterContextLinux_x86_64::CopyXSTATEtoYMM(
917     uint32_t reg_index, lldb::ByteOrder byte_order) {
918   if (!IsAVX(reg_index))
919     return false;
920 
921   if (byte_order == lldb::eByteOrderLittle) {
922     uint32_t reg_no = reg_index - m_reg_info.first_ymm;
923     m_ymm_set.ymm[reg_no] = XStateToYMM(
924         m_xstate->fxsave.xmm[reg_no].bytes,
925         m_xstate->xsave.ymmh[reg_no].bytes);
926     return true;
927   }
928 
929   return false; // unsupported or invalid byte order
930 }
931 
CopyYMMtoXSTATE(uint32_t reg,lldb::ByteOrder byte_order)932 bool NativeRegisterContextLinux_x86_64::CopyYMMtoXSTATE(
933     uint32_t reg, lldb::ByteOrder byte_order) {
934   if (!IsAVX(reg))
935     return false;
936 
937   if (byte_order == lldb::eByteOrderLittle) {
938     uint32_t reg_no = reg - m_reg_info.first_ymm;
939     YMMToXState(m_ymm_set.ymm[reg_no],
940         m_xstate->fxsave.xmm[reg_no].bytes,
941         m_xstate->xsave.ymmh[reg_no].bytes);
942     return true;
943   }
944 
945   return false; // unsupported or invalid byte order
946 }
947 
GetFPRBuffer()948 void *NativeRegisterContextLinux_x86_64::GetFPRBuffer() {
949   switch (m_xstate_type) {
950   case XStateType::FXSAVE:
951     return &m_xstate->fxsave;
952   case XStateType::XSAVE:
953     return &m_iovec;
954   default:
955     return nullptr;
956   }
957 }
958 
GetFPRSize()959 size_t NativeRegisterContextLinux_x86_64::GetFPRSize() {
960   switch (m_xstate_type) {
961   case XStateType::FXSAVE:
962     return sizeof(m_xstate->fxsave);
963   case XStateType::XSAVE:
964     return sizeof(m_iovec);
965   default:
966     return 0;
967   }
968 }
969 
ReadFPR()970 Status NativeRegisterContextLinux_x86_64::ReadFPR() {
971   Status error;
972 
973   // Probe XSAVE and if it is not supported fall back to FXSAVE.
974   if (m_xstate_type != XStateType::FXSAVE) {
975     error = ReadRegisterSet(&m_iovec, sizeof(m_xstate->xsave), NT_X86_XSTATE);
976     if (!error.Fail()) {
977       m_xstate_type = XStateType::XSAVE;
978       return error;
979     }
980   }
981   error = ReadRegisterSet(
982       &m_iovec, sizeof(m_xstate->xsave),
983       fxsr_regset(GetRegisterInfoInterface().GetTargetArchitecture()));
984   if (!error.Fail()) {
985     m_xstate_type = XStateType::FXSAVE;
986     return error;
987   }
988   return Status("Unrecognized FPR type.");
989 }
990 
IsMPX(uint32_t reg_index) const991 bool NativeRegisterContextLinux_x86_64::IsMPX(uint32_t reg_index) const {
992   if (!IsCPUFeatureAvailable(RegSet::mpx))
993     return false;
994   return (m_reg_info.first_mpxr <= reg_index &&
995           reg_index <= m_reg_info.last_mpxc);
996 }
997 
CopyXSTATEtoMPX(uint32_t reg)998 bool NativeRegisterContextLinux_x86_64::CopyXSTATEtoMPX(uint32_t reg) {
999   if (!IsMPX(reg))
1000     return false;
1001 
1002   if (reg >= m_reg_info.first_mpxr && reg <= m_reg_info.last_mpxr) {
1003     ::memcpy(m_mpx_set.mpxr[reg - m_reg_info.first_mpxr].bytes,
1004              m_xstate->xsave.mpxr[reg - m_reg_info.first_mpxr].bytes,
1005              sizeof(MPXReg));
1006   } else {
1007     ::memcpy(m_mpx_set.mpxc[reg - m_reg_info.first_mpxc].bytes,
1008              m_xstate->xsave.mpxc[reg - m_reg_info.first_mpxc].bytes,
1009              sizeof(MPXCsr));
1010   }
1011   return true;
1012 }
1013 
CopyMPXtoXSTATE(uint32_t reg)1014 bool NativeRegisterContextLinux_x86_64::CopyMPXtoXSTATE(uint32_t reg) {
1015   if (!IsMPX(reg))
1016     return false;
1017 
1018   if (reg >= m_reg_info.first_mpxr && reg <= m_reg_info.last_mpxr) {
1019     ::memcpy(m_xstate->xsave.mpxr[reg - m_reg_info.first_mpxr].bytes,
1020              m_mpx_set.mpxr[reg - m_reg_info.first_mpxr].bytes, sizeof(MPXReg));
1021   } else {
1022     ::memcpy(m_xstate->xsave.mpxc[reg - m_reg_info.first_mpxc].bytes,
1023              m_mpx_set.mpxc[reg - m_reg_info.first_mpxc].bytes, sizeof(MPXCsr));
1024   }
1025   return true;
1026 }
1027 
1028 uint32_t
GetPtraceOffset(uint32_t reg_index)1029 NativeRegisterContextLinux_x86_64::GetPtraceOffset(uint32_t reg_index) {
1030   // If register is MPX, remove extra factor from gdb offset
1031   return GetRegisterInfoAtIndex(reg_index)->byte_offset -
1032          (IsMPX(reg_index) ? 128 : 0);
1033 }
1034 
1035 llvm::Optional<NativeRegisterContextLinux::SyscallData>
GetSyscallData()1036 NativeRegisterContextLinux_x86_64::GetSyscallData() {
1037   switch (GetRegisterInfoInterface().GetTargetArchitecture().GetMachine()) {
1038   case llvm::Triple::x86: {
1039     static const uint8_t Int80[] = {0xcd, 0x80};
1040     static const uint32_t Args[] = {lldb_eax_i386, lldb_ebx_i386, lldb_ecx_i386,
1041                                     lldb_edx_i386, lldb_esi_i386, lldb_edi_i386,
1042                                     lldb_ebp_i386};
1043     return SyscallData{Int80, Args, lldb_eax_i386};
1044   }
1045   case llvm::Triple::x86_64: {
1046     static const uint8_t Syscall[] = {0x0f, 0x05};
1047     static const uint32_t Args[] = {
1048         lldb_rax_x86_64, lldb_rdi_x86_64, lldb_rsi_x86_64, lldb_rdx_x86_64,
1049         lldb_r10_x86_64, lldb_r8_x86_64,  lldb_r9_x86_64};
1050     return SyscallData{Syscall, Args, lldb_rax_x86_64};
1051   }
1052   default:
1053     llvm_unreachable("Unhandled architecture!");
1054   }
1055 }
1056 
1057 llvm::Optional<NativeRegisterContextLinux::MmapData>
GetMmapData()1058 NativeRegisterContextLinux_x86_64::GetMmapData() {
1059   switch (GetRegisterInfoInterface().GetTargetArchitecture().GetMachine()) {
1060   case llvm::Triple::x86:
1061     return MmapData{192, 91};
1062   case llvm::Triple::x86_64:
1063     return MmapData{9, 11};
1064   default:
1065     llvm_unreachable("Unhandled architecture!");
1066   }
1067 }
1068 
1069 #endif // defined(__i386__) || defined(__x86_64__)
1070