1 //===--------------------------- libunwind.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 // Implements unw_* functions from <libunwind.h>
9 //
10 //===----------------------------------------------------------------------===//
11
12 #include <libunwind.h>
13
14 #include "libunwind_ext.h"
15 #include "config.h"
16
17 #include <stdlib.h>
18
19
20 #if !defined(__USING_SJLJ_EXCEPTIONS__)
21 #include "AddressSpace.hpp"
22 #include "UnwindCursor.hpp"
23
24 using namespace libunwind;
25
26 /// internal object to represent this processes address space
27 LocalAddressSpace LocalAddressSpace::sThisAddressSpace;
28
29 _LIBUNWIND_EXPORT unw_addr_space_t unw_local_addr_space =
30 (unw_addr_space_t)&LocalAddressSpace::sThisAddressSpace;
31
32 /// Create a cursor of a thread in this process given 'context' recorded by
33 /// __unw_getcontext().
__unw_init_local(unw_cursor_t * cursor,unw_context_t * context)34 _LIBUNWIND_HIDDEN int __unw_init_local(unw_cursor_t *cursor,
35 unw_context_t *context) {
36 _LIBUNWIND_TRACE_API("__unw_init_local(cursor=%p, context=%p)",
37 static_cast<void *>(cursor),
38 static_cast<void *>(context));
39 #if defined(__i386__)
40 # define REGISTER_KIND Registers_x86
41 #elif defined(__x86_64__)
42 # define REGISTER_KIND Registers_x86_64
43 #elif defined(__powerpc64__)
44 # define REGISTER_KIND Registers_ppc64
45 #elif defined(__ppc__)
46 # define REGISTER_KIND Registers_ppc
47 #elif defined(__aarch64__)
48 # define REGISTER_KIND Registers_arm64
49 #elif defined(__arm__)
50 # define REGISTER_KIND Registers_arm
51 #elif defined(__or1k__)
52 # define REGISTER_KIND Registers_or1k
53 #elif defined(__mips__) && defined(_ABIO32) && _MIPS_SIM == _ABIO32
54 # define REGISTER_KIND Registers_mips_o32
55 #elif defined(__mips64)
56 # define REGISTER_KIND Registers_mips_newabi
57 #elif defined(__mips__)
58 # warning The MIPS architecture is not supported with this ABI and environment!
59 #elif defined(__sparc__)
60 # define REGISTER_KIND Registers_sparc
61 #elif defined(__riscv) && __riscv_xlen == 64
62 # define REGISTER_KIND Registers_riscv
63 #else
64 # error Architecture not supported
65 #endif
66 // Use "placement new" to allocate UnwindCursor in the cursor buffer.
67 new (reinterpret_cast<UnwindCursor<LocalAddressSpace, REGISTER_KIND> *>(cursor))
68 UnwindCursor<LocalAddressSpace, REGISTER_KIND>(
69 context, LocalAddressSpace::sThisAddressSpace);
70 #undef REGISTER_KIND
71 AbstractUnwindCursor *co = (AbstractUnwindCursor *)cursor;
72 co->setInfoBasedOnIPRegister();
73
74 return UNW_ESUCCESS;
75 }
_LIBUNWIND_WEAK_ALIAS(__unw_init_local,unw_init_local)76 _LIBUNWIND_WEAK_ALIAS(__unw_init_local, unw_init_local)
77
78 /// Get value of specified register at cursor position in stack frame.
79 _LIBUNWIND_HIDDEN int __unw_get_reg(unw_cursor_t *cursor, unw_regnum_t regNum,
80 unw_word_t *value) {
81 _LIBUNWIND_TRACE_API("__unw_get_reg(cursor=%p, regNum=%d, &value=%p)",
82 static_cast<void *>(cursor), regNum,
83 static_cast<void *>(value));
84 AbstractUnwindCursor *co = (AbstractUnwindCursor *)cursor;
85 if (co->validReg(regNum)) {
86 *value = co->getReg(regNum);
87 return UNW_ESUCCESS;
88 }
89 return UNW_EBADREG;
90 }
_LIBUNWIND_WEAK_ALIAS(__unw_get_reg,unw_get_reg)91 _LIBUNWIND_WEAK_ALIAS(__unw_get_reg, unw_get_reg)
92
93 /// Set value of specified register at cursor position in stack frame.
94 _LIBUNWIND_HIDDEN int __unw_set_reg(unw_cursor_t *cursor, unw_regnum_t regNum,
95 unw_word_t value) {
96 _LIBUNWIND_TRACE_API("__unw_set_reg(cursor=%p, regNum=%d, value=0x%" PRIxPTR
97 ")",
98 static_cast<void *>(cursor), regNum, value);
99 typedef LocalAddressSpace::pint_t pint_t;
100 AbstractUnwindCursor *co = (AbstractUnwindCursor *)cursor;
101 if (co->validReg(regNum)) {
102 co->setReg(regNum, (pint_t)value);
103 // specical case altering IP to re-find info (being called by personality
104 // function)
105 if (regNum == UNW_REG_IP) {
106 unw_proc_info_t info;
107 // First, get the FDE for the old location and then update it.
108 co->getInfo(&info);
109 co->setInfoBasedOnIPRegister(false);
110 // If the original call expects stack adjustment, perform this now.
111 // Normal frame unwinding would have included the offset already in the
112 // CFA computation.
113 // Note: for PA-RISC and other platforms where the stack grows up,
114 // this should actually be - info.gp. LLVM doesn't currently support
115 // any such platforms and Clang doesn't export a macro for them.
116 if (info.gp)
117 co->setReg(UNW_REG_SP, co->getReg(UNW_REG_SP) + info.gp);
118 }
119 return UNW_ESUCCESS;
120 }
121 return UNW_EBADREG;
122 }
_LIBUNWIND_WEAK_ALIAS(__unw_set_reg,unw_set_reg)123 _LIBUNWIND_WEAK_ALIAS(__unw_set_reg, unw_set_reg)
124
125 /// Get value of specified float register at cursor position in stack frame.
126 _LIBUNWIND_HIDDEN int __unw_get_fpreg(unw_cursor_t *cursor, unw_regnum_t regNum,
127 unw_fpreg_t *value) {
128 _LIBUNWIND_TRACE_API("__unw_get_fpreg(cursor=%p, regNum=%d, &value=%p)",
129 static_cast<void *>(cursor), regNum,
130 static_cast<void *>(value));
131 AbstractUnwindCursor *co = (AbstractUnwindCursor *)cursor;
132 if (co->validFloatReg(regNum)) {
133 *value = co->getFloatReg(regNum);
134 return UNW_ESUCCESS;
135 }
136 return UNW_EBADREG;
137 }
_LIBUNWIND_WEAK_ALIAS(__unw_get_fpreg,unw_get_fpreg)138 _LIBUNWIND_WEAK_ALIAS(__unw_get_fpreg, unw_get_fpreg)
139
140 /// Set value of specified float register at cursor position in stack frame.
141 _LIBUNWIND_HIDDEN int __unw_set_fpreg(unw_cursor_t *cursor, unw_regnum_t regNum,
142 unw_fpreg_t value) {
143 #if defined(_LIBUNWIND_ARM_EHABI)
144 _LIBUNWIND_TRACE_API("__unw_set_fpreg(cursor=%p, regNum=%d, value=%llX)",
145 static_cast<void *>(cursor), regNum, value);
146 #else
147 _LIBUNWIND_TRACE_API("__unw_set_fpreg(cursor=%p, regNum=%d, value=%g)",
148 static_cast<void *>(cursor), regNum, value);
149 #endif
150 AbstractUnwindCursor *co = (AbstractUnwindCursor *)cursor;
151 if (co->validFloatReg(regNum)) {
152 co->setFloatReg(regNum, value);
153 return UNW_ESUCCESS;
154 }
155 return UNW_EBADREG;
156 }
_LIBUNWIND_WEAK_ALIAS(__unw_set_fpreg,unw_set_fpreg)157 _LIBUNWIND_WEAK_ALIAS(__unw_set_fpreg, unw_set_fpreg)
158
159 /// Move cursor to next frame.
160 _LIBUNWIND_HIDDEN int __unw_step(unw_cursor_t *cursor) {
161 _LIBUNWIND_TRACE_API("__unw_step(cursor=%p)", static_cast<void *>(cursor));
162 AbstractUnwindCursor *co = (AbstractUnwindCursor *)cursor;
163 return co->step();
164 }
_LIBUNWIND_WEAK_ALIAS(__unw_step,unw_step)165 _LIBUNWIND_WEAK_ALIAS(__unw_step, unw_step)
166
167 /// Get unwind info at cursor position in stack frame.
168 _LIBUNWIND_HIDDEN int __unw_get_proc_info(unw_cursor_t *cursor,
169 unw_proc_info_t *info) {
170 _LIBUNWIND_TRACE_API("__unw_get_proc_info(cursor=%p, &info=%p)",
171 static_cast<void *>(cursor), static_cast<void *>(info));
172 AbstractUnwindCursor *co = (AbstractUnwindCursor *)cursor;
173 co->getInfo(info);
174 if (info->end_ip == 0)
175 return UNW_ENOINFO;
176 return UNW_ESUCCESS;
177 }
_LIBUNWIND_WEAK_ALIAS(__unw_get_proc_info,unw_get_proc_info)178 _LIBUNWIND_WEAK_ALIAS(__unw_get_proc_info, unw_get_proc_info)
179
180 /// Resume execution at cursor position (aka longjump).
181 _LIBUNWIND_HIDDEN int __unw_resume(unw_cursor_t *cursor) {
182 _LIBUNWIND_TRACE_API("__unw_resume(cursor=%p)", static_cast<void *>(cursor));
183 AbstractUnwindCursor *co = (AbstractUnwindCursor *)cursor;
184 co->jumpto();
185 return UNW_EUNSPEC;
186 }
_LIBUNWIND_WEAK_ALIAS(__unw_resume,unw_resume)187 _LIBUNWIND_WEAK_ALIAS(__unw_resume, unw_resume)
188
189 /// Get name of function at cursor position in stack frame.
190 _LIBUNWIND_HIDDEN int __unw_get_proc_name(unw_cursor_t *cursor, char *buf,
191 size_t bufLen, unw_word_t *offset) {
192 _LIBUNWIND_TRACE_API("__unw_get_proc_name(cursor=%p, &buf=%p, bufLen=%lu)",
193 static_cast<void *>(cursor), static_cast<void *>(buf),
194 static_cast<unsigned long>(bufLen));
195 AbstractUnwindCursor *co = (AbstractUnwindCursor *)cursor;
196 if (co->getFunctionName(buf, bufLen, offset))
197 return UNW_ESUCCESS;
198 return UNW_EUNSPEC;
199 }
_LIBUNWIND_WEAK_ALIAS(__unw_get_proc_name,unw_get_proc_name)200 _LIBUNWIND_WEAK_ALIAS(__unw_get_proc_name, unw_get_proc_name)
201
202 /// Checks if a register is a floating-point register.
203 _LIBUNWIND_HIDDEN int __unw_is_fpreg(unw_cursor_t *cursor,
204 unw_regnum_t regNum) {
205 _LIBUNWIND_TRACE_API("__unw_is_fpreg(cursor=%p, regNum=%d)",
206 static_cast<void *>(cursor), regNum);
207 AbstractUnwindCursor *co = (AbstractUnwindCursor *)cursor;
208 return co->validFloatReg(regNum);
209 }
_LIBUNWIND_WEAK_ALIAS(__unw_is_fpreg,unw_is_fpreg)210 _LIBUNWIND_WEAK_ALIAS(__unw_is_fpreg, unw_is_fpreg)
211
212 /// Checks if a register is a floating-point register.
213 _LIBUNWIND_HIDDEN const char *__unw_regname(unw_cursor_t *cursor,
214 unw_regnum_t regNum) {
215 _LIBUNWIND_TRACE_API("__unw_regname(cursor=%p, regNum=%d)",
216 static_cast<void *>(cursor), regNum);
217 AbstractUnwindCursor *co = (AbstractUnwindCursor *)cursor;
218 return co->getRegisterName(regNum);
219 }
_LIBUNWIND_WEAK_ALIAS(__unw_regname,unw_regname)220 _LIBUNWIND_WEAK_ALIAS(__unw_regname, unw_regname)
221
222 /// Checks if current frame is signal trampoline.
223 _LIBUNWIND_HIDDEN int __unw_is_signal_frame(unw_cursor_t *cursor) {
224 _LIBUNWIND_TRACE_API("__unw_is_signal_frame(cursor=%p)",
225 static_cast<void *>(cursor));
226 AbstractUnwindCursor *co = (AbstractUnwindCursor *)cursor;
227 return co->isSignalFrame();
228 }
_LIBUNWIND_WEAK_ALIAS(__unw_is_signal_frame,unw_is_signal_frame)229 _LIBUNWIND_WEAK_ALIAS(__unw_is_signal_frame, unw_is_signal_frame)
230
231 #ifdef __arm__
232 // Save VFP registers d0-d15 using FSTMIADX instead of FSTMIADD
233 _LIBUNWIND_HIDDEN void __unw_save_vfp_as_X(unw_cursor_t *cursor) {
234 _LIBUNWIND_TRACE_API("__unw_get_fpreg_save_vfp_as_X(cursor=%p)",
235 static_cast<void *>(cursor));
236 AbstractUnwindCursor *co = (AbstractUnwindCursor *)cursor;
237 return co->saveVFPAsX();
238 }
_LIBUNWIND_WEAK_ALIAS(__unw_save_vfp_as_X,unw_save_vfp_as_X)239 _LIBUNWIND_WEAK_ALIAS(__unw_save_vfp_as_X, unw_save_vfp_as_X)
240 #endif
241
242
243 #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
244 /// SPI: walks cached DWARF entries
245 _LIBUNWIND_HIDDEN void __unw_iterate_dwarf_unwind_cache(void (*func)(
246 unw_word_t ip_start, unw_word_t ip_end, unw_word_t fde, unw_word_t mh)) {
247 _LIBUNWIND_TRACE_API("__unw_iterate_dwarf_unwind_cache(func=%p)",
248 reinterpret_cast<void *>(func));
249 DwarfFDECache<LocalAddressSpace>::iterateCacheEntries(func);
250 }
_LIBUNWIND_WEAK_ALIAS(__unw_iterate_dwarf_unwind_cache,unw_iterate_dwarf_unwind_cache)251 _LIBUNWIND_WEAK_ALIAS(__unw_iterate_dwarf_unwind_cache,
252 unw_iterate_dwarf_unwind_cache)
253
254 /// IPI: for __register_frame()
255 void __unw_add_dynamic_fde(unw_word_t fde) {
256 CFI_Parser<LocalAddressSpace>::FDE_Info fdeInfo;
257 CFI_Parser<LocalAddressSpace>::CIE_Info cieInfo;
258 const char *message = CFI_Parser<LocalAddressSpace>::decodeFDE(
259 LocalAddressSpace::sThisAddressSpace,
260 (LocalAddressSpace::pint_t) fde, &fdeInfo, &cieInfo);
261 if (message == NULL) {
262 // dynamically registered FDEs don't have a mach_header group they are in.
263 // Use fde as mh_group
264 unw_word_t mh_group = fdeInfo.fdeStart;
265 DwarfFDECache<LocalAddressSpace>::add((LocalAddressSpace::pint_t)mh_group,
266 fdeInfo.pcStart, fdeInfo.pcEnd,
267 fdeInfo.fdeStart);
268 } else {
269 _LIBUNWIND_DEBUG_LOG("__unw_add_dynamic_fde: bad fde: %s", message);
270 }
271 }
272
273 /// IPI: for __deregister_frame()
__unw_remove_dynamic_fde(unw_word_t fde)274 void __unw_remove_dynamic_fde(unw_word_t fde) {
275 // fde is own mh_group
276 DwarfFDECache<LocalAddressSpace>::removeAllIn((LocalAddressSpace::pint_t)fde);
277 }
278 #endif // defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
279 #endif // !defined(__USING_SJLJ_EXCEPTIONS__)
280
281
282
283 // Add logging hooks in Debug builds only
284 #ifndef NDEBUG
285 #include <stdlib.h>
286
287 _LIBUNWIND_HIDDEN
logAPIs()288 bool logAPIs() {
289 // do manual lock to avoid use of _cxa_guard_acquire or initializers
290 static bool checked = false;
291 static bool log = false;
292 if (!checked) {
293 log = (getenv("LIBUNWIND_PRINT_APIS") != NULL);
294 checked = true;
295 }
296 return log;
297 }
298
299 _LIBUNWIND_HIDDEN
logUnwinding()300 bool logUnwinding() {
301 // do manual lock to avoid use of _cxa_guard_acquire or initializers
302 static bool checked = false;
303 static bool log = false;
304 if (!checked) {
305 log = (getenv("LIBUNWIND_PRINT_UNWINDING") != NULL);
306 checked = true;
307 }
308 return log;
309 }
310
311 _LIBUNWIND_HIDDEN
logDWARF()312 bool logDWARF() {
313 // do manual lock to avoid use of _cxa_guard_acquire or initializers
314 static bool checked = false;
315 static bool log = false;
316 if (!checked) {
317 log = (getenv("LIBUNWIND_PRINT_DWARF") != NULL);
318 checked = true;
319 }
320 return log;
321 }
322
323 #endif // NDEBUG
324
325