unwind-dw2-xtensa.c revision 1.2.8.2
1 1.2.8.2 tls /* DWARF2 exception handling and frame unwinding for Xtensa. 2 1.2.8.2 tls Copyright (C) 1997-2013 Free Software Foundation, Inc. 3 1.2.8.2 tls 4 1.2.8.2 tls This file is part of GCC. 5 1.2.8.2 tls 6 1.2.8.2 tls GCC is free software; you can redistribute it and/or modify it 7 1.2.8.2 tls under the terms of the GNU General Public License as published by 8 1.2.8.2 tls the Free Software Foundation; either version 3, or (at your option) 9 1.2.8.2 tls any later version. 10 1.2.8.2 tls 11 1.2.8.2 tls GCC is distributed in the hope that it will be useful, but WITHOUT 12 1.2.8.2 tls ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 13 1.2.8.2 tls or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public 14 1.2.8.2 tls License for more details. 15 1.2.8.2 tls 16 1.2.8.2 tls Under Section 7 of GPL version 3, you are granted additional 17 1.2.8.2 tls permissions described in the GCC Runtime Library Exception, version 18 1.2.8.2 tls 3.1, as published by the Free Software Foundation. 19 1.2.8.2 tls 20 1.2.8.2 tls You should have received a copy of the GNU General Public License and 21 1.2.8.2 tls a copy of the GCC Runtime Library Exception along with this program; 22 1.2.8.2 tls see the files COPYING3 and COPYING.RUNTIME respectively. If not, see 23 1.2.8.2 tls <http://www.gnu.org/licenses/>. */ 24 1.2.8.2 tls 25 1.2.8.2 tls #include "tconfig.h" 26 1.2.8.2 tls #include "tsystem.h" 27 1.2.8.2 tls #include "coretypes.h" 28 1.2.8.2 tls #include "tm.h" 29 1.2.8.2 tls #include "libgcc_tm.h" 30 1.2.8.2 tls #include "dwarf2.h" 31 1.2.8.2 tls #include "unwind.h" 32 1.2.8.2 tls #ifdef __USING_SJLJ_EXCEPTIONS__ 33 1.2.8.2 tls # define NO_SIZE_OF_ENCODED_VALUE 34 1.2.8.2 tls #endif 35 1.2.8.2 tls #include "unwind-pe.h" 36 1.2.8.2 tls #include "unwind-dw2-fde.h" 37 1.2.8.2 tls #include "unwind-dw2-xtensa.h" 38 1.2.8.2 tls 39 1.2.8.2 tls #ifndef __USING_SJLJ_EXCEPTIONS__ 40 1.2.8.2 tls 41 1.2.8.2 tls /* The standard CIE and FDE structures work fine for Xtensa but the 42 1.2.8.2 tls variable-size register window save areas are not a good fit for the rest 43 1.2.8.2 tls of the standard DWARF unwinding mechanism. Nor is that mechanism 44 1.2.8.2 tls necessary, since the register save areas are always in fixed locations 45 1.2.8.2 tls in each stack frame. This file is a stripped down and customized version 46 1.2.8.2 tls of the standard DWARF unwinding code. It needs to be customized to have 47 1.2.8.2 tls builtin logic for finding the save areas and also to track the stack 48 1.2.8.2 tls pointer value (besides the CFA) while unwinding since the primary save 49 1.2.8.2 tls area is located below the stack pointer. It is stripped down to reduce 50 1.2.8.2 tls code size and ease the maintenance burden of tracking changes in the 51 1.2.8.2 tls standard version of the code. */ 52 1.2.8.2 tls 53 1.2.8.2 tls #ifndef DWARF_REG_TO_UNWIND_COLUMN 54 1.2.8.2 tls #define DWARF_REG_TO_UNWIND_COLUMN(REGNO) (REGNO) 55 1.2.8.2 tls #endif 56 1.2.8.2 tls 57 1.2.8.2 tls #define XTENSA_RA_FIELD_MASK 0x3FFFFFFF 58 1.2.8.2 tls 59 1.2.8.2 tls /* This is the register and unwind state for a particular frame. This 60 1.2.8.2 tls provides the information necessary to unwind up past a frame and return 61 1.2.8.2 tls to its caller. */ 62 1.2.8.2 tls struct _Unwind_Context 63 1.2.8.2 tls { 64 1.2.8.2 tls /* Track register window save areas of 4 registers each, instead of 65 1.2.8.2 tls keeping separate addresses for the individual registers. */ 66 1.2.8.2 tls _Unwind_Word *reg[4]; 67 1.2.8.2 tls 68 1.2.8.2 tls void *cfa; 69 1.2.8.2 tls void *sp; 70 1.2.8.2 tls void *ra; 71 1.2.8.2 tls 72 1.2.8.2 tls /* Cache the 2 high bits to replace the window size in return addresses. */ 73 1.2.8.2 tls _Unwind_Word ra_high_bits; 74 1.2.8.2 tls 75 1.2.8.2 tls void *lsda; 76 1.2.8.2 tls struct dwarf_eh_bases bases; 77 1.2.8.2 tls /* Signal frame context. */ 78 1.2.8.2 tls #define SIGNAL_FRAME_BIT ((~(_Unwind_Word) 0 >> 1) + 1) 79 1.2.8.2 tls _Unwind_Word flags; 80 1.2.8.2 tls /* 0 for now, can be increased when further fields are added to 81 1.2.8.2 tls struct _Unwind_Context. */ 82 1.2.8.2 tls _Unwind_Word version; 83 1.2.8.2 tls }; 84 1.2.8.2 tls 85 1.2.8.2 tls 86 1.2.8.2 tls /* Read unaligned data from the instruction buffer. */ 88 1.2.8.2 tls 89 1.2.8.2 tls union unaligned 90 1.2.8.2 tls { 91 1.2.8.2 tls void *p; 92 1.2.8.2 tls } __attribute__ ((packed)); 93 1.2.8.2 tls 94 1.2.8.2 tls static void uw_update_context (struct _Unwind_Context *, _Unwind_FrameState *); 95 1.2.8.2 tls static _Unwind_Reason_Code uw_frame_state_for (struct _Unwind_Context *, 96 1.2.8.2 tls _Unwind_FrameState *); 97 1.2.8.2 tls 98 1.2.8.2 tls static inline void * 99 1.2.8.2 tls read_pointer (const void *p) { const union unaligned *up = p; return up->p; } 100 1.2.8.2 tls 101 1.2.8.2 tls static inline _Unwind_Word 103 1.2.8.2 tls _Unwind_IsSignalFrame (struct _Unwind_Context *context) 104 1.2.8.2 tls { 105 1.2.8.2 tls return (context->flags & SIGNAL_FRAME_BIT) ? 1 : 0; 106 1.2.8.2 tls } 107 1.2.8.2 tls 108 1.2.8.2 tls static inline void 109 1.2.8.2 tls _Unwind_SetSignalFrame (struct _Unwind_Context *context, int val) 110 1.2.8.2 tls { 111 1.2.8.2 tls if (val) 112 1.2.8.2 tls context->flags |= SIGNAL_FRAME_BIT; 113 1.2.8.2 tls else 114 1.2.8.2 tls context->flags &= ~SIGNAL_FRAME_BIT; 115 1.2.8.2 tls } 116 1.2.8.2 tls 117 1.2.8.2 tls /* Get the value of register INDEX as saved in CONTEXT. */ 119 1.2.8.2 tls 120 1.2.8.2 tls inline _Unwind_Word 121 1.2.8.2 tls _Unwind_GetGR (struct _Unwind_Context *context, int index) 122 1.2.8.2 tls { 123 1.2.8.2 tls _Unwind_Word *ptr; 124 1.2.8.2 tls 125 1.2.8.2 tls index = DWARF_REG_TO_UNWIND_COLUMN (index); 126 1.2.8.2 tls ptr = context->reg[index >> 2] + (index & 3); 127 1.2.8.2 tls 128 1.2.8.2 tls return *ptr; 129 1.2.8.2 tls } 130 1.2.8.2 tls 131 1.2.8.2 tls /* Get the value of the CFA as saved in CONTEXT. */ 132 1.2.8.2 tls 133 1.2.8.2 tls _Unwind_Word 134 1.2.8.2 tls _Unwind_GetCFA (struct _Unwind_Context *context) 135 1.2.8.2 tls { 136 1.2.8.2 tls return (_Unwind_Ptr) context->cfa; 137 1.2.8.2 tls } 138 1.2.8.2 tls 139 1.2.8.2 tls /* Overwrite the saved value for register INDEX in CONTEXT with VAL. */ 140 1.2.8.2 tls 141 1.2.8.2 tls inline void 142 1.2.8.2 tls _Unwind_SetGR (struct _Unwind_Context *context, int index, _Unwind_Word val) 143 1.2.8.2 tls { 144 1.2.8.2 tls _Unwind_Word *ptr; 145 1.2.8.2 tls 146 1.2.8.2 tls index = DWARF_REG_TO_UNWIND_COLUMN (index); 147 1.2.8.2 tls ptr = context->reg[index >> 2] + (index & 3); 148 1.2.8.2 tls 149 1.2.8.2 tls *ptr = val; 150 1.2.8.2 tls } 151 1.2.8.2 tls 152 1.2.8.2 tls /* Retrieve the return address for CONTEXT. */ 153 1.2.8.2 tls 154 1.2.8.2 tls inline _Unwind_Ptr 155 1.2.8.2 tls _Unwind_GetIP (struct _Unwind_Context *context) 156 1.2.8.2 tls { 157 1.2.8.2 tls return (_Unwind_Ptr) context->ra; 158 1.2.8.2 tls } 159 1.2.8.2 tls 160 1.2.8.2 tls /* Retrieve the return address and flag whether that IP is before 161 1.2.8.2 tls or after first not yet fully executed instruction. */ 162 1.2.8.2 tls 163 1.2.8.2 tls inline _Unwind_Ptr 164 1.2.8.2 tls _Unwind_GetIPInfo (struct _Unwind_Context *context, int *ip_before_insn) 165 1.2.8.2 tls { 166 1.2.8.2 tls *ip_before_insn = _Unwind_IsSignalFrame (context); 167 1.2.8.2 tls return (_Unwind_Ptr) context->ra; 168 1.2.8.2 tls } 169 1.2.8.2 tls 170 1.2.8.2 tls /* Overwrite the return address for CONTEXT with VAL. */ 171 1.2.8.2 tls 172 1.2.8.2 tls inline void 173 1.2.8.2 tls _Unwind_SetIP (struct _Unwind_Context *context, _Unwind_Ptr val) 174 1.2.8.2 tls { 175 1.2.8.2 tls context->ra = (void *) val; 176 1.2.8.2 tls } 177 1.2.8.2 tls 178 1.2.8.2 tls _Unwind_Ptr 179 1.2.8.2 tls _Unwind_GetLanguageSpecificData (struct _Unwind_Context *context) 180 1.2.8.2 tls { 181 1.2.8.2 tls return context->lsda; 182 1.2.8.2 tls } 183 1.2.8.2 tls 184 1.2.8.2 tls _Unwind_Ptr 185 1.2.8.2 tls _Unwind_GetRegionStart (struct _Unwind_Context *context) 186 1.2.8.2 tls { 187 1.2.8.2 tls return (_Unwind_Ptr) context->bases.func; 188 1.2.8.2 tls } 189 1.2.8.2 tls 190 1.2.8.2 tls void * 191 1.2.8.2 tls _Unwind_FindEnclosingFunction (void *pc) 192 1.2.8.2 tls { 193 1.2.8.2 tls struct dwarf_eh_bases bases; 194 1.2.8.2 tls const struct dwarf_fde *fde = _Unwind_Find_FDE (pc-1, &bases); 195 1.2.8.2 tls if (fde) 196 1.2.8.2 tls return bases.func; 197 1.2.8.2 tls else 198 1.2.8.2 tls return NULL; 199 1.2.8.2 tls } 200 1.2.8.2 tls 201 1.2.8.2 tls _Unwind_Ptr 202 1.2.8.2 tls _Unwind_GetDataRelBase (struct _Unwind_Context *context) 203 1.2.8.2 tls { 204 1.2.8.2 tls return (_Unwind_Ptr) context->bases.dbase; 205 1.2.8.2 tls } 206 1.2.8.2 tls 207 1.2.8.2 tls _Unwind_Ptr 208 1.2.8.2 tls _Unwind_GetTextRelBase (struct _Unwind_Context *context) 209 1.2.8.2 tls { 210 1.2.8.2 tls return (_Unwind_Ptr) context->bases.tbase; 211 1.2.8.2 tls } 212 1.2.8.2 tls 213 1.2.8.2 tls #include "md-unwind-support.h" 214 1.2.8.2 tls 215 1.2.8.2 tls /* Extract any interesting information from the CIE for the translation 217 1.2.8.2 tls unit F belongs to. Return a pointer to the byte after the augmentation, 218 1.2.8.2 tls or NULL if we encountered an undecipherable augmentation. */ 219 1.2.8.2 tls 220 1.2.8.2 tls static const unsigned char * 221 1.2.8.2 tls extract_cie_info (const struct dwarf_cie *cie, struct _Unwind_Context *context, 222 1.2.8.2 tls _Unwind_FrameState *fs) 223 1.2.8.2 tls { 224 1.2.8.2 tls const unsigned char *aug = cie->augmentation; 225 1.2.8.2 tls const unsigned char *p = aug + strlen ((const char *)aug) + 1; 226 1.2.8.2 tls const unsigned char *ret = NULL; 227 1.2.8.2 tls _uleb128_t utmp; 228 1.2.8.2 tls _sleb128_t stmp; 229 1.2.8.2 tls 230 1.2.8.2 tls /* g++ v2 "eh" has pointer immediately following augmentation string, 231 1.2.8.2 tls so it must be handled first. */ 232 1.2.8.2 tls if (aug[0] == 'e' && aug[1] == 'h') 233 1.2.8.2 tls { 234 1.2.8.2 tls fs->eh_ptr = read_pointer (p); 235 1.2.8.2 tls p += sizeof (void *); 236 1.2.8.2 tls aug += 2; 237 1.2.8.2 tls } 238 1.2.8.2 tls 239 1.2.8.2 tls /* Immediately following the augmentation are the code and 240 1.2.8.2 tls data alignment and return address column. */ 241 1.2.8.2 tls p = read_uleb128 (p, &utmp); 242 1.2.8.2 tls p = read_sleb128 (p, &stmp); 243 1.2.8.2 tls if (cie->version == 1) 244 1.2.8.2 tls fs->retaddr_column = *p++; 245 1.2.8.2 tls else 246 1.2.8.2 tls { 247 1.2.8.2 tls p = read_uleb128 (p, &utmp); 248 1.2.8.2 tls fs->retaddr_column = (_Unwind_Word)utmp; 249 1.2.8.2 tls } 250 1.2.8.2 tls fs->lsda_encoding = DW_EH_PE_omit; 251 1.2.8.2 tls 252 1.2.8.2 tls /* If the augmentation starts with 'z', then a uleb128 immediately 253 1.2.8.2 tls follows containing the length of the augmentation field following 254 1.2.8.2 tls the size. */ 255 1.2.8.2 tls if (*aug == 'z') 256 1.2.8.2 tls { 257 1.2.8.2 tls p = read_uleb128 (p, &utmp); 258 1.2.8.2 tls ret = p + utmp; 259 1.2.8.2 tls 260 1.2.8.2 tls fs->saw_z = 1; 261 1.2.8.2 tls ++aug; 262 1.2.8.2 tls } 263 1.2.8.2 tls 264 1.2.8.2 tls /* Iterate over recognized augmentation subsequences. */ 265 1.2.8.2 tls while (*aug != '\0') 266 1.2.8.2 tls { 267 1.2.8.2 tls /* "L" indicates a byte showing how the LSDA pointer is encoded. */ 268 1.2.8.2 tls if (aug[0] == 'L') 269 1.2.8.2 tls { 270 1.2.8.2 tls fs->lsda_encoding = *p++; 271 1.2.8.2 tls aug += 1; 272 1.2.8.2 tls } 273 1.2.8.2 tls 274 1.2.8.2 tls /* "R" indicates a byte indicating how FDE addresses are encoded. */ 275 1.2.8.2 tls else if (aug[0] == 'R') 276 1.2.8.2 tls { 277 1.2.8.2 tls fs->fde_encoding = *p++; 278 1.2.8.2 tls aug += 1; 279 1.2.8.2 tls } 280 1.2.8.2 tls 281 1.2.8.2 tls /* "P" indicates a personality routine in the CIE augmentation. */ 282 1.2.8.2 tls else if (aug[0] == 'P') 283 1.2.8.2 tls { 284 1.2.8.2 tls _Unwind_Ptr personality; 285 1.2.8.2 tls 286 1.2.8.2 tls p = read_encoded_value (context, *p, p + 1, &personality); 287 1.2.8.2 tls fs->personality = (_Unwind_Personality_Fn) personality; 288 1.2.8.2 tls aug += 1; 289 1.2.8.2 tls } 290 1.2.8.2 tls 291 1.2.8.2 tls /* "S" indicates a signal frame. */ 292 1.2.8.2 tls else if (aug[0] == 'S') 293 1.2.8.2 tls { 294 1.2.8.2 tls fs->signal_frame = 1; 295 1.2.8.2 tls aug += 1; 296 1.2.8.2 tls } 297 1.2.8.2 tls 298 1.2.8.2 tls /* Otherwise we have an unknown augmentation string. 299 1.2.8.2 tls Bail unless we saw a 'z' prefix. */ 300 1.2.8.2 tls else 301 1.2.8.2 tls return ret; 302 1.2.8.2 tls } 303 1.2.8.2 tls 304 1.2.8.2 tls return ret ? ret : p; 305 1.2.8.2 tls } 306 1.2.8.2 tls 307 1.2.8.2 tls /* Given the _Unwind_Context CONTEXT for a stack frame, look up the FDE for 309 1.2.8.2 tls its caller and decode it into FS. This function also sets the 310 1.2.8.2 tls lsda member of CONTEXT, as it is really information 311 1.2.8.2 tls about the caller's frame. */ 312 1.2.8.2 tls 313 1.2.8.2 tls static _Unwind_Reason_Code 314 1.2.8.2 tls uw_frame_state_for (struct _Unwind_Context *context, _Unwind_FrameState *fs) 315 1.2.8.2 tls { 316 1.2.8.2 tls const struct dwarf_fde *fde; 317 1.2.8.2 tls const struct dwarf_cie *cie; 318 1.2.8.2 tls const unsigned char *aug; 319 1.2.8.2 tls int window_size; 320 1.2.8.2 tls _Unwind_Word *ra_ptr; 321 1.2.8.2 tls 322 1.2.8.2 tls memset (fs, 0, sizeof (*fs)); 323 1.2.8.2 tls context->lsda = 0; 324 1.2.8.2 tls 325 1.2.8.2 tls fde = _Unwind_Find_FDE (context->ra + _Unwind_IsSignalFrame (context) - 1, 326 1.2.8.2 tls &context->bases); 327 1.2.8.2 tls if (fde == NULL) 328 1.2.8.2 tls { 329 1.2.8.2 tls #ifdef MD_FALLBACK_FRAME_STATE_FOR 330 1.2.8.2 tls _Unwind_Reason_Code reason; 331 1.2.8.2 tls /* Couldn't find frame unwind info for this function. Try a 332 1.2.8.2 tls target-specific fallback mechanism. This will necessarily 333 1.2.8.2 tls not provide a personality routine or LSDA. */ 334 1.2.8.2 tls reason = MD_FALLBACK_FRAME_STATE_FOR (context, fs); 335 1.2.8.2 tls if (reason != _URC_END_OF_STACK) 336 1.2.8.2 tls return reason; 337 1.2.8.2 tls #endif 338 1.2.8.2 tls /* The frame was not recognized and handled by the fallback function, 339 1.2.8.2 tls but it is not really the end of the stack. Fall through here and 340 1.2.8.2 tls unwind it anyway. */ 341 1.2.8.2 tls } 342 1.2.8.2 tls else 343 1.2.8.2 tls { 344 1.2.8.2 tls cie = get_cie (fde); 345 1.2.8.2 tls if (extract_cie_info (cie, context, fs) == NULL) 346 1.2.8.2 tls /* CIE contained unknown augmentation. */ 347 1.2.8.2 tls return _URC_FATAL_PHASE1_ERROR; 348 1.2.8.2 tls 349 1.2.8.2 tls /* Locate augmentation for the fde. */ 350 1.2.8.2 tls aug = (const unsigned char *) fde + sizeof (*fde); 351 1.2.8.2 tls aug += 2 * size_of_encoded_value (fs->fde_encoding); 352 1.2.8.2 tls if (fs->saw_z) 353 1.2.8.2 tls { 354 1.2.8.2 tls _uleb128_t i; 355 1.2.8.2 tls aug = read_uleb128 (aug, &i); 356 1.2.8.2 tls } 357 1.2.8.2 tls if (fs->lsda_encoding != DW_EH_PE_omit) 358 1.2.8.2 tls { 359 1.2.8.2 tls _Unwind_Ptr lsda; 360 1.2.8.2 tls 361 1.2.8.2 tls aug = read_encoded_value (context, fs->lsda_encoding, aug, &lsda); 362 1.2.8.2 tls context->lsda = (void *) lsda; 363 1.2.8.2 tls } 364 1.2.8.2 tls } 365 1.2.8.2 tls 366 1.2.8.2 tls /* Check for the end of the stack. This needs to be checked after 367 1.2.8.2 tls the MD_FALLBACK_FRAME_STATE_FOR check for signal frames because 368 1.2.8.2 tls the contents of context->reg[0] are undefined at a signal frame, 369 1.2.8.2 tls and register a0 may appear to be zero. (The return address in 370 1.2.8.2 tls context->ra comes from register a4 or a8). */ 371 1.2.8.2 tls ra_ptr = context->reg[0]; 372 1.2.8.2 tls if (ra_ptr && *ra_ptr == 0) 373 1.2.8.2 tls return _URC_END_OF_STACK; 374 1.2.8.2 tls 375 1.2.8.2 tls /* Find the window size from the high bits of the return address. */ 376 1.2.8.2 tls if (ra_ptr) 377 1.2.8.2 tls window_size = (*ra_ptr >> 30) * 4; 378 1.2.8.2 tls else 379 1.2.8.2 tls window_size = 8; 380 1.2.8.2 tls 381 1.2.8.2 tls fs->retaddr_column = window_size; 382 1.2.8.2 tls 383 1.2.8.2 tls return _URC_NO_REASON; 384 1.2.8.2 tls } 385 1.2.8.2 tls 386 1.2.8.2 tls static void 388 1.2.8.2 tls uw_update_context_1 (struct _Unwind_Context *context, _Unwind_FrameState *fs) 389 1.2.8.2 tls { 390 1.2.8.2 tls struct _Unwind_Context orig_context = *context; 391 1.2.8.2 tls _Unwind_Word *sp, *cfa, *next_cfa; 392 1.2.8.2 tls int i; 393 1.2.8.2 tls 394 1.2.8.2 tls if (fs->signal_regs) 395 1.2.8.2 tls { 396 1.2.8.2 tls cfa = (_Unwind_Word *) fs->signal_regs[1]; 397 1.2.8.2 tls next_cfa = (_Unwind_Word *) cfa[-3]; 398 1.2.8.2 tls 399 1.2.8.2 tls for (i = 0; i < 4; i++) 400 1.2.8.2 tls context->reg[i] = fs->signal_regs + (i << 2); 401 1.2.8.2 tls } 402 1.2.8.2 tls else 403 1.2.8.2 tls { 404 1.2.8.2 tls int window_size = fs->retaddr_column >> 2; 405 1.2.8.2 tls 406 1.2.8.2 tls sp = (_Unwind_Word *) orig_context.sp; 407 1.2.8.2 tls cfa = (_Unwind_Word *) orig_context.cfa; 408 1.2.8.2 tls next_cfa = (_Unwind_Word *) cfa[-3]; 409 1.2.8.2 tls 410 1.2.8.2 tls /* Registers a0-a3 are in the save area below sp. */ 411 1.2.8.2 tls context->reg[0] = sp - 4; 412 1.2.8.2 tls 413 1.2.8.2 tls /* Find the extra save area below next_cfa. */ 414 1.2.8.2 tls for (i = 1; i < window_size; i++) 415 1.2.8.2 tls context->reg[i] = next_cfa - 4 * (1 + window_size - i); 416 1.2.8.2 tls 417 1.2.8.2 tls /* Remaining registers rotate from previous save areas. */ 418 1.2.8.2 tls for (i = window_size; i < 4; i++) 419 1.2.8.2 tls context->reg[i] = orig_context.reg[i - window_size]; 420 1.2.8.2 tls } 421 1.2.8.2 tls 422 1.2.8.2 tls context->sp = cfa; 423 1.2.8.2 tls context->cfa = next_cfa; 424 1.2.8.2 tls 425 1.2.8.2 tls _Unwind_SetSignalFrame (context, fs->signal_frame); 426 1.2.8.2 tls } 427 1.2.8.2 tls 428 1.2.8.2 tls /* CONTEXT describes the unwind state for a frame, and FS describes the FDE 429 1.2.8.2 tls of its caller. Update CONTEXT to refer to the caller as well. Note 430 1.2.8.2 tls that the lsda member is not updated here, but later in 431 1.2.8.2 tls uw_frame_state_for. */ 432 1.2.8.2 tls 433 1.2.8.2 tls static void 434 1.2.8.2 tls uw_update_context (struct _Unwind_Context *context, _Unwind_FrameState *fs) 435 1.2.8.2 tls { 436 1.2.8.2 tls uw_update_context_1 (context, fs); 437 1.2.8.2 tls 438 1.2.8.2 tls /* Compute the return address now, since the return address column 439 1.2.8.2 tls can change from frame to frame. */ 440 1.2.8.2 tls if (fs->signal_ra != 0) 441 1.2.8.2 tls context->ra = (void *) fs->signal_ra; 442 1.2.8.2 tls else 443 1.2.8.2 tls context->ra = (void *) ((_Unwind_GetGR (context, fs->retaddr_column) 444 1.2.8.2 tls & XTENSA_RA_FIELD_MASK) | context->ra_high_bits); 445 1.2.8.2 tls } 446 1.2.8.2 tls 447 1.2.8.2 tls static void 448 1.2.8.2 tls uw_advance_context (struct _Unwind_Context *context, _Unwind_FrameState *fs) 449 1.2.8.2 tls { 450 1.2.8.2 tls uw_update_context (context, fs); 451 1.2.8.2 tls } 452 1.2.8.2 tls 453 1.2.8.2 tls /* Fill in CONTEXT for top-of-stack. The only valid registers at this 455 1.2.8.2 tls level will be the return address and the CFA. */ 456 1.2.8.2 tls 457 1.2.8.2 tls #define uw_init_context(CONTEXT) \ 458 1.2.8.2 tls do \ 459 1.2.8.2 tls { \ 460 1.2.8.2 tls __builtin_unwind_init (); \ 461 1.2.8.2 tls uw_init_context_1 (CONTEXT, __builtin_dwarf_cfa (), \ 462 1.2.8.2 tls __builtin_return_address (0)); \ 463 1.2.8.2 tls } \ 464 1.2.8.2 tls while (0) 465 1.2.8.2 tls 466 1.2.8.2 tls static void __attribute__((noinline)) 467 1.2.8.2 tls uw_init_context_1 (struct _Unwind_Context *context, void *outer_cfa, 468 1.2.8.2 tls void *outer_ra) 469 1.2.8.2 tls { 470 1.2.8.2 tls void *ra = __builtin_return_address (0); 471 1.2.8.2 tls void *cfa = __builtin_dwarf_cfa (); 472 1.2.8.2 tls _Unwind_FrameState fs; 473 1.2.8.2 tls 474 1.2.8.2 tls memset (context, 0, sizeof (struct _Unwind_Context)); 475 1.2.8.2 tls context->ra = ra; 476 1.2.8.2 tls 477 1.2.8.2 tls memset (&fs, 0, sizeof (fs)); 478 1.2.8.2 tls fs.retaddr_column = 8; 479 1.2.8.2 tls context->sp = cfa; 480 1.2.8.2 tls context->cfa = outer_cfa; 481 1.2.8.2 tls context->ra_high_bits = 482 1.2.8.2 tls ((_Unwind_Word) uw_init_context_1) & ~XTENSA_RA_FIELD_MASK; 483 1.2.8.2 tls uw_update_context_1 (context, &fs); 484 1.2.8.2 tls 485 1.2.8.2 tls context->ra = outer_ra; 486 1.2.8.2 tls } 487 1.2.8.2 tls 488 1.2.8.2 tls 489 1.2.8.2 tls /* Install TARGET into CURRENT so that we can return to it. This is a 490 1.2.8.2 tls macro because __builtin_eh_return must be invoked in the context of 491 1.2.8.2 tls our caller. */ 492 1.2.8.2 tls 493 1.2.8.2 tls #define uw_install_context(CURRENT, TARGET) \ 494 1.2.8.2 tls do \ 495 1.2.8.2 tls { \ 496 1.2.8.2 tls long offset = uw_install_context_1 ((CURRENT), (TARGET)); \ 497 1.2.8.2 tls void *handler = __builtin_frob_return_addr ((TARGET)->ra); \ 498 1.2.8.2 tls __builtin_eh_return (offset, handler); \ 499 1.2.8.2 tls } \ 500 1.2.8.2 tls while (0) 501 1.2.8.2 tls 502 1.2.8.2 tls static long 503 1.2.8.2 tls uw_install_context_1 (struct _Unwind_Context *current, 504 1.2.8.2 tls struct _Unwind_Context *target) 505 1.2.8.2 tls { 506 1.2.8.2 tls long i; 507 1.2.8.2 tls 508 1.2.8.2 tls /* The eh_return insn assumes a window size of 8, so don't bother copying 509 1.2.8.2 tls the save areas for registers a8-a15 since they won't be reloaded. */ 510 1.2.8.2 tls for (i = 0; i < 2; ++i) 511 1.2.8.2 tls { 512 1.2.8.2 tls void *c = current->reg[i]; 513 1.2.8.2 tls void *t = target->reg[i]; 514 1.2.8.2 tls 515 1.2.8.2 tls if (t && c && t != c) 516 1.2.8.2 tls memcpy (c, t, 4 * sizeof (_Unwind_Word)); 517 1.2.8.2 tls } 518 1.2.8.2 tls 519 1.2.8.2 tls return 0; 520 1.2.8.2 tls } 521 1.2.8.2 tls 522 1.2.8.2 tls static inline _Unwind_Ptr 523 1.2.8.2 tls uw_identify_context (struct _Unwind_Context *context) 524 1.2.8.2 tls { 525 1.2.8.2 tls return _Unwind_GetCFA (context); 526 1.2.8.2 tls } 527 1.2.8.2 tls 528 1.2.8.2 tls 529 1.2.8.2 tls #include "unwind.inc" 530 1.2.8.2 tls 531 1.2.8.2 tls #if defined (USE_GAS_SYMVER) && defined (SHARED) && defined (USE_LIBUNWIND_EXCEPTIONS) 532 1.2.8.2 tls alias (_Unwind_Backtrace); 533 1.2.8.2 tls alias (_Unwind_DeleteException); 534 1.2.8.2 tls alias (_Unwind_FindEnclosingFunction); 535 1.2.8.2 tls alias (_Unwind_ForcedUnwind); 536 1.2.8.2 tls alias (_Unwind_GetDataRelBase); 537 1.2.8.2 tls alias (_Unwind_GetTextRelBase); 538 1.2.8.2 tls alias (_Unwind_GetCFA); 539 1.2.8.2 tls alias (_Unwind_GetGR); 540 1.2.8.2 tls alias (_Unwind_GetIP); 541 1.2.8.2 tls alias (_Unwind_GetLanguageSpecificData); 542 1.2.8.2 tls alias (_Unwind_GetRegionStart); 543 1.2.8.2 tls alias (_Unwind_RaiseException); 544 alias (_Unwind_Resume); 545 alias (_Unwind_Resume_or_Rethrow); 546 alias (_Unwind_SetGR); 547 alias (_Unwind_SetIP); 548 #endif 549 550 #endif /* !USING_SJLJ_EXCEPTIONS */ 551
Indexes created Wed Apr 29 00:23:26 UTC 2026