1 /* libunwind - a platform-independent unwind library 2 Copyright (C) 2001-2005 Hewlett-Packard Co 3 Contributed by David Mosberger-Tang <davidm (at) hpl.hp.com> 4 5 This file is part of libunwind. 6 7 Permission is hereby granted, free of charge, to any person obtaining 8 a copy of this software and associated documentation files (the 9 "Software"), to deal in the Software without restriction, including 10 without limitation the rights to use, copy, modify, merge, publish, 11 distribute, sublicense, and/or sell copies of the Software, and to 12 permit persons to whom the Software is furnished to do so, subject to 13 the following conditions: 14 15 The above copyright notice and this permission notice shall be 16 included in all copies or substantial portions of the Software. 17 18 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 19 EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 20 MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 21 NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE 22 LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION 23 OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION 24 WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */ 25 26 #include "offsets.h" 27 #include "unwind_i.h" 28 29 static inline int 30 linux_sigtramp (struct cursor *c, ia64_loc_t prev_cfm_loc, 31 unw_word_t *num_regsp) 32 { 33 #if defined(UNW_LOCAL_ONLY) && !defined(__linux) 34 return -UNW_EINVAL; 35 #else 36 unw_word_t sc_addr; 37 int ret; 38 39 if ((ret = ia64_get (c, IA64_LOC_ADDR (c->sp + 0x10 40 + LINUX_SIGFRAME_ARG2_OFF, 0), 41 &sc_addr)) < 0) 42 return ret; 43 44 c->sigcontext_addr = sc_addr; 45 46 if (!IA64_IS_REG_LOC (c->loc[IA64_REG_IP]) 47 && IA64_GET_ADDR (c->loc[IA64_REG_IP]) == sc_addr + LINUX_SC_BR_OFF + 8) 48 { 49 /* Linux kernels before 2.4.19 and 2.5.10 had buggy 50 unwind info for sigtramp. Fix it up here. */ 51 c->loc[IA64_REG_IP] = IA64_LOC_ADDR (sc_addr + LINUX_SC_IP_OFF, 0); 52 c->cfm_loc = IA64_LOC_ADDR (sc_addr + LINUX_SC_CFM_OFF, 0); 53 } 54 55 /* do what can't be described by unwind directives: */ 56 c->loc[IA64_REG_PFS] = IA64_LOC_ADDR (sc_addr + LINUX_SC_AR_PFS_OFF, 0); 57 c->ec_loc = prev_cfm_loc; 58 *num_regsp = c->cfm & 0x7f; /* size of frame */ 59 return 0; 60 #endif 61 } 62 63 static inline int 64 linux_interrupt (struct cursor *c, ia64_loc_t prev_cfm_loc, 65 unw_word_t *num_regsp, int marker) 66 { 67 #if defined(UNW_LOCAL_ONLY) && !(defined(__linux) && defined(__KERNEL__)) 68 return -UNW_EINVAL; 69 #else 70 unw_word_t sc_addr, num_regs; 71 ia64_loc_t pfs_loc; 72 73 sc_addr = c->sigcontext_addr = c->sp + 0x10; 74 75 if ((c->pr & (1UL << LINUX_PT_P_NONSYS)) != 0) 76 num_regs = c->cfm & 0x7f; 77 else 78 num_regs = 0; 79 80 /* do what can't be described by unwind directives: */ 81 if (marker == ABI_MARKER_OLD_LINUX_INTERRUPT) 82 pfs_loc = IA64_LOC_ADDR (sc_addr + LINUX_OLD_PT_PFS_OFF, 0); 83 else 84 pfs_loc = IA64_LOC_ADDR (sc_addr + LINUX_PT_PFS_OFF, 0); 85 c->loc[IA64_REG_PFS] = pfs_loc; 86 c->ec_loc = prev_cfm_loc; 87 *num_regsp = num_regs; /* size of frame */ 88 return 0; 89 #endif 90 } 91 92 static inline int 93 hpux_sigtramp (struct cursor *c, ia64_loc_t prev_cfm_loc, 94 unw_word_t *num_regsp) 95 { 96 #if defined(UNW_LOCAL_ONLY) && !defined(__hpux) 97 return -UNW_EINVAL; 98 #else 99 unw_word_t sc_addr, bsp, bspstore; 100 ia64_loc_t sc_loc; 101 int ret, i; 102 103 /* HP-UX passes the address of ucontext_t in r32: */ 104 if ((ret = ia64_get_stacked (c, 32, &sc_loc, NULL)) < 0) 105 return ret; 106 if ((ret = ia64_get (c, sc_loc, &sc_addr)) < 0) 107 return ret; 108 109 c->sigcontext_addr = sc_addr; 110 111 /* Now mark all (preserved) registers as coming from the 112 signal context: */ 113 c->cfm_loc = IA64_LOC_UC_REG (UNW_IA64_CFM, sc_addr); 114 c->loc[IA64_REG_PRI_UNAT_MEM] = IA64_NULL_LOC; 115 c->loc[IA64_REG_PSP] = IA64_LOC_UC_REG (UNW_IA64_GR + 12, sc_addr); 116 c->loc[IA64_REG_BSP] = IA64_LOC_UC_REG (UNW_IA64_AR_BSP, sc_addr); 117 c->loc[IA64_REG_BSPSTORE] = IA64_LOC_UC_REG (UNW_IA64_AR_BSPSTORE, sc_addr); 118 c->loc[IA64_REG_PFS] = IA64_LOC_UC_REG (UNW_IA64_AR_PFS, sc_addr); 119 c->loc[IA64_REG_RNAT] = IA64_LOC_UC_REG (UNW_IA64_AR_RNAT, sc_addr); 120 c->loc[IA64_REG_IP] = IA64_LOC_UC_REG (UNW_IA64_IP, sc_addr); 121 c->loc[IA64_REG_R4] = IA64_LOC_UC_REG (UNW_IA64_GR + 4, sc_addr); 122 c->loc[IA64_REG_R5] = IA64_LOC_UC_REG (UNW_IA64_GR + 5, sc_addr); 123 c->loc[IA64_REG_R6] = IA64_LOC_UC_REG (UNW_IA64_GR + 6, sc_addr); 124 c->loc[IA64_REG_R7] = IA64_LOC_UC_REG (UNW_IA64_GR + 7, sc_addr); 125 c->loc[IA64_REG_NAT4] = IA64_LOC_UC_REG (UNW_IA64_NAT + 4, sc_addr); 126 c->loc[IA64_REG_NAT5] = IA64_LOC_UC_REG (UNW_IA64_NAT + 5, sc_addr); 127 c->loc[IA64_REG_NAT6] = IA64_LOC_UC_REG (UNW_IA64_NAT + 6, sc_addr); 128 c->loc[IA64_REG_NAT7] = IA64_LOC_UC_REG (UNW_IA64_NAT + 7, sc_addr); 129 c->loc[IA64_REG_UNAT] = IA64_LOC_UC_REG (UNW_IA64_AR_UNAT, sc_addr); 130 c->loc[IA64_REG_PR] = IA64_LOC_UC_REG (UNW_IA64_PR, sc_addr); 131 c->loc[IA64_REG_LC] = IA64_LOC_UC_REG (UNW_IA64_AR_LC, sc_addr); 132 c->loc[IA64_REG_FPSR] = IA64_LOC_UC_REG (UNW_IA64_AR_FPSR, sc_addr); 133 c->loc[IA64_REG_B1] = IA64_LOC_UC_REG (UNW_IA64_BR + 1, sc_addr); 134 c->loc[IA64_REG_B2] = IA64_LOC_UC_REG (UNW_IA64_BR + 2, sc_addr); 135 c->loc[IA64_REG_B3] = IA64_LOC_UC_REG (UNW_IA64_BR + 3, sc_addr); 136 c->loc[IA64_REG_B4] = IA64_LOC_UC_REG (UNW_IA64_BR + 4, sc_addr); 137 c->loc[IA64_REG_B5] = IA64_LOC_UC_REG (UNW_IA64_BR + 5, sc_addr); 138 c->loc[IA64_REG_F2] = IA64_LOC_UC_REG (UNW_IA64_FR + 2, sc_addr); 139 c->loc[IA64_REG_F3] = IA64_LOC_UC_REG (UNW_IA64_FR + 3, sc_addr); 140 c->loc[IA64_REG_F4] = IA64_LOC_UC_REG (UNW_IA64_FR + 4, sc_addr); 141 c->loc[IA64_REG_F5] = IA64_LOC_UC_REG (UNW_IA64_FR + 5, sc_addr); 142 for (i = 0; i < 16; ++i) 143 c->loc[IA64_REG_F16 + i] = IA64_LOC_UC_REG (UNW_IA64_FR + 16 + i, sc_addr); 144 145 c->pi.flags |= UNW_PI_FLAG_IA64_RBS_SWITCH; 146 147 /* update the CFM cache: */ 148 if ((ret = ia64_get (c, c->cfm_loc, &c->cfm)) < 0) 149 return ret; 150 /* update the PSP cache: */ 151 if ((ret = ia64_get (c, c->loc[IA64_REG_PSP], &c->psp)) < 0) 152 return ret; 153 154 if ((ret = ia64_get (c, c->loc[IA64_REG_BSP], &bsp)) < 0 155 || (ret = ia64_get (c, c->loc[IA64_REG_BSPSTORE], &bspstore)) < 0) 156 return ret; 157 if (bspstore < bsp) 158 /* Dirty partition got spilled into the ucontext_t structure 159 itself. We'll need to access it via uc_access(3). */ 160 rbs_switch (c, bsp, bspstore, IA64_LOC_UC_ADDR (bsp | 0x1f8, 0)); 161 162 c->ec_loc = prev_cfm_loc; 163 164 *num_regsp = 0; 165 return 0; 166 #endif 167 } 168 169 170 static inline int 171 check_rbs_switch (struct cursor *c) 172 { 173 unw_word_t saved_bsp, saved_bspstore, loadrs, ndirty; 174 int ret = 0; 175 176 saved_bsp = c->bsp; 177 if (c->pi.flags & UNW_PI_FLAG_IA64_RBS_SWITCH) 178 { 179 /* Got ourselves a frame that has saved ar.bspstore, ar.bsp, 180 and ar.rnat, so we're all set for rbs-switching: */ 181 if ((ret = ia64_get (c, c->loc[IA64_REG_BSP], &saved_bsp)) < 0 182 || (ret = ia64_get (c, c->loc[IA64_REG_BSPSTORE], &saved_bspstore))) 183 return ret; 184 } 185 else if ((c->abi_marker == ABI_MARKER_LINUX_SIGTRAMP 186 || c->abi_marker == ABI_MARKER_OLD_LINUX_SIGTRAMP) 187 && !IA64_IS_REG_LOC (c->loc[IA64_REG_BSP]) 188 && (IA64_GET_ADDR (c->loc[IA64_REG_BSP]) 189 == c->sigcontext_addr + LINUX_SC_AR_BSP_OFF)) 190 { 191 /* When Linux delivers a signal on an alternate stack, it 192 does things a bit differently from what the unwind 193 conventions allow us to describe: instead of saving 194 ar.rnat, ar.bsp, and ar.bspstore, it saves the former two 195 plus the "loadrs" value. Because of this, we need to 196 detect & record a potential rbs-area switch 197 manually... */ 198 199 /* If ar.bsp has been saved already AND the current bsp is 200 not equal to the saved value, then we know for sure that 201 we're past the point where the backing store has been 202 switched (and before the point where it's restored). */ 203 if ((ret = ia64_get (c, IA64_LOC_ADDR (c->sigcontext_addr 204 + LINUX_SC_AR_BSP_OFF, 0), 205 &saved_bsp) < 0) 206 || (ret = ia64_get (c, IA64_LOC_ADDR (c->sigcontext_addr 207 + LINUX_SC_LOADRS_OFF, 0), 208 &loadrs) < 0)) 209 return ret; 210 loadrs >>= 16; 211 ndirty = rse_num_regs (c->bsp - loadrs, c->bsp); 212 saved_bspstore = rse_skip_regs (saved_bsp, -ndirty); 213 } 214 215 if (saved_bsp == c->bsp) 216 return 0; 217 218 return rbs_switch (c, saved_bsp, saved_bspstore, c->loc[IA64_REG_RNAT]); 219 } 220 221 static inline int 222 update_frame_state (struct cursor *c) 223 { 224 unw_word_t prev_ip, prev_sp, prev_bsp, ip, num_regs; 225 ia64_loc_t prev_cfm_loc; 226 int ret; 227 228 prev_cfm_loc = c->cfm_loc; 229 prev_ip = c->ip; 230 prev_sp = c->sp; 231 prev_bsp = c->bsp; 232 233 /* Update the IP cache (do this first: if we reach the end of the 234 frame-chain, the rest of the info may not be valid/useful 235 anymore. */ 236 ret = ia64_get (c, c->loc[IA64_REG_IP], &ip); 237 if (ret < 0) 238 return ret; 239 c->ip = ip; 240 241 if ((ip & 0xc) != 0) 242 { 243 /* don't let obviously bad addresses pollute the cache */ 244 Debug (1, "rejecting bad ip=0x%lx\n", (long) c->ip); 245 return -UNW_EINVALIDIP; 246 } 247 248 c->cfm_loc = c->loc[IA64_REG_PFS]; 249 /* update the CFM cache: */ 250 ret = ia64_get (c, c->cfm_loc, &c->cfm); 251 if (ret < 0) 252 return ret; 253 254 /* Normally, AR.EC is stored in the CFM save-location. That 255 save-location contains the full function-state as defined by 256 AR.PFS. However, interruptions only save the frame-marker, not 257 any other info in CFM. Instead, AR.EC gets saved on the first 258 call by the interruption-handler. Thus, interruption-related 259 frames need to track the _previous_ CFM save-location since 260 that's were AR.EC is saved. We support this by setting ec_loc to 261 cfm_loc by default and giving frames marked with an ABI-marker 262 the chance to override this value with prev_cfm_loc. */ 263 c->ec_loc = c->cfm_loc; 264 265 num_regs = 0; 266 if (unlikely (c->abi_marker)) 267 { 268 c->last_abi_marker = c->abi_marker; 269 switch (ia64_get_abi_marker (c)) 270 { 271 case ABI_MARKER_LINUX_SIGTRAMP: 272 case ABI_MARKER_OLD_LINUX_SIGTRAMP: 273 ia64_set_abi (c, ABI_LINUX); 274 if ((ret = linux_sigtramp (c, prev_cfm_loc, &num_regs)) < 0) 275 return ret; 276 break; 277 278 case ABI_MARKER_OLD_LINUX_INTERRUPT: 279 case ABI_MARKER_LINUX_INTERRUPT: 280 ia64_set_abi (c, ABI_LINUX); 281 if ((ret = linux_interrupt (c, prev_cfm_loc, &num_regs, 282 c->abi_marker)) < 0) 283 return ret; 284 break; 285 286 case ABI_MARKER_HP_UX_SIGTRAMP: 287 ia64_set_abi (c, ABI_HPUX); 288 if ((ret = hpux_sigtramp (c, prev_cfm_loc, &num_regs)) < 0) 289 return ret; 290 break; 291 292 default: 293 Debug (1, "unknown ABI marker: ABI=%u, context=%u\n", 294 c->abi_marker >> 8, c->abi_marker & 0xff); 295 return -UNW_EINVAL; 296 } 297 Debug (12, "sigcontext_addr=%lx (ret=%d)\n", 298 (unsigned long) c->sigcontext_addr, ret); 299 300 c->sigcontext_off = c->sigcontext_addr - c->sp; 301 302 /* update the IP cache: */ 303 if ((ret = ia64_get (c, c->loc[IA64_REG_IP], &ip)) < 0) 304 return ret; 305 c->ip = ip; 306 if (ip == 0) 307 /* end of frame-chain reached */ 308 return 0; 309 } 310 else 311 num_regs = (c->cfm >> 7) & 0x7f; /* size of locals */ 312 313 if (!IA64_IS_NULL_LOC (c->loc[IA64_REG_BSP])) 314 { 315 ret = check_rbs_switch (c); 316 if (ret < 0) 317 return ret; 318 } 319 320 c->bsp = rse_skip_regs (c->bsp, -num_regs); 321 322 c->sp = c->psp; 323 c->abi_marker = 0; 324 325 if (c->ip == prev_ip && c->sp == prev_sp && c->bsp == prev_bsp) 326 { 327 Dprintf ("%s: ip, sp, and bsp unchanged; stopping here (ip=0x%lx)\n", 328 __FUNCTION__, (long) ip); 329 return -UNW_EBADFRAME; 330 } 331 332 /* as we unwind, the saved ar.unat becomes the primary unat: */ 333 c->loc[IA64_REG_PRI_UNAT_MEM] = c->loc[IA64_REG_UNAT]; 334 335 /* restore the predicates: */ 336 ret = ia64_get (c, c->loc[IA64_REG_PR], &c->pr); 337 if (ret < 0) 338 return ret; 339 340 c->pi_valid = 0; 341 return 0; 342 } 343 344 345 PROTECTED int 346 unw_step (unw_cursor_t *cursor) 347 { 348 struct cursor *c = (struct cursor *) cursor; 349 int ret; 350 351 Debug (1, "(cursor=%p, ip=0x%016lx)\n", c, (unsigned long) c->ip); 352 353 if ((ret = ia64_find_save_locs (c)) >= 0 354 && (ret = update_frame_state (c)) >= 0) 355 ret = (c->ip == 0) ? 0 : 1; 356 357 Debug (2, "returning %d (ip=0x%016lx)\n", ret, (unsigned long) c->ip); 358 return ret; 359 } 360
