src/libs/libunwind/ia64/Gstep.c

   1 /* libunwind - a platform-independent unwind library
   2    Copyright (C) 2001-2005 Hewlett-Packard Co
   3         Contributed by David Mosberger-Tang <davidm@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 }