src/libs/libunwind/arm/Ginit.c

   1 /* libunwind - a platform-independent unwind library
   2    Copyright (C) 2008 CodeSourcery
   3
   4 This file is part of libunwind.
   5
   6 Permission is hereby granted, free of charge, to any person obtaining
   7 a copy of this software and associated documentation files (the
   8 "Software"), to deal in the Software without restriction, including
   9 without limitation the rights to use, copy, modify, merge, publish,
  10 distribute, sublicense, and/or sell copies of the Software, and to
  11 permit persons to whom the Software is furnished to do so, subject to
  12 the following conditions:
  13
  14 The above copyright notice and this permission notice shall be
  15 included in all copies or substantial portions of the Software.
  16
  17 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  18 EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  19 MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  20 NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  21 LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  22 OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  23 WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.  */
  24
  25 #include <stdlib.h>
  26 #include <string.h>
  27
  28 #include "unwind_i.h"
  29
  30 #ifdef UNW_REMOTE_ONLY
  31
  32 /* unw_local_addr_space is a NULL pointer in this case.  */
  33 PROTECTED unw_addr_space_t unw_local_addr_space;
  34
  35 #else /* !UNW_REMOTE_ONLY */
  36
  37 static struct unw_addr_space local_addr_space;
  38
  39 PROTECTED unw_addr_space_t unw_local_addr_space = &local_addr_space;
  40
  41 static inline void *
  42 uc_addr (unw_tdep_context_t *uc, int reg)
  43 {
  44   if (reg >= UNW_ARM_R0 && reg < UNW_ARM_R0 + 16)
  45     return &uc->regs[reg - UNW_ARM_R0];
  46   else
  47     return NULL;
  48 }
  49
  50 # ifdef UNW_LOCAL_ONLY
  51
  52 HIDDEN void *
  53 tdep_uc_addr (unw_tdep_context_t *uc, int reg)
  54 {
  55   return uc_addr (uc, reg);
  56 }
  57
  58 # endif /* UNW_LOCAL_ONLY */
  59
  60 HIDDEN unw_dyn_info_list_t _U_dyn_info_list;
  61
  62 /* XXX fix me: there is currently no way to locate the dyn-info list
  63        by a remote unwinder.  On ia64, this is done via a special
  64        unwind-table entry.  Perhaps something similar can be done with
  65        DWARF2 unwind info.  */
  66
  67 static int
  68 get_dyn_info_list_addr (unw_addr_space_t as, unw_word_t *dyn_info_list_addr,
  69                         void *arg)
  70 {
  71   *dyn_info_list_addr = (unw_word_t) &_U_dyn_info_list;
  72   return 0;
  73 }
  74
  75 #define PAGE_SIZE 4096
  76 #define PAGE_START(a)   ((a) & ~(PAGE_SIZE-1))
  77
  78 /* Cache of already validated addresses */
  79 #define NLGA 4
  80 static unw_word_t last_good_addr[NLGA];
  81 static int lga_victim;
  82
  83 static int
  84 validate_mem (unw_word_t addr)
  85 {
  86   int i, victim;
  87   size_t len;
  88
  89   if (PAGE_START(addr + sizeof (unw_word_t) - 1) == PAGE_START(addr))
  90     len = PAGE_SIZE;
  91   else
  92     len = PAGE_SIZE * 2;
  93
  94   addr = PAGE_START(addr);
  95
  96   if (addr == 0)
  97     return -1;
  98
  99   for (i = 0; i < NLGA; i++)
 100     {
 101       if (last_good_addr[i] && (addr == last_good_addr[i]))
 102       return 0;
 103     }
 104
 105   if (msync ((void *) addr, len, MS_ASYNC) == -1)
 106     return -1;
 107
 108   victim = lga_victim;
 109   for (i = 0; i < NLGA; i++) {
 110     if (!last_good_addr[victim]) {
 111       last_good_addr[victim++] = addr;
 112       return 0;
 113     }
 114     victim = (victim + 1) % NLGA;
 115   }
 116
 117   /* All slots full. Evict the victim. */
 118   last_good_addr[victim] = addr;
 119   victim = (victim + 1) % NLGA;
 120   lga_victim = victim;
 121
 122   return 0;
 123 }
 124
 125 static int
 126 access_mem (unw_addr_space_t as, unw_word_t addr, unw_word_t *val, int write,
 127             void *arg)
 128 {
 129   if (write)
 130     {
 131       Debug (16, "mem[%x] <- %x\n", addr, *val);
 132       *(unw_word_t *) addr = *val;
 133     }
 134   else
 135     {
 136       /* validate address */
 137       const struct cursor *c = (const struct cursor *) arg;
 138       if (c && validate_mem(addr))
 139         return -1;
 140
 141       *val = *(unw_word_t *) addr;
 142       Debug (16, "mem[%x] -> %x\n", addr, *val);
 143     }
 144   return 0;
 145 }
 146
 147 static int
 148 access_reg (unw_addr_space_t as, unw_regnum_t reg, unw_word_t *val, int write,
 149             void *arg)
 150 {
 151   unw_word_t *addr;
 152   unw_tdep_context_t *uc = arg;
 153
 154   if (unw_is_fpreg (reg))
 155     goto badreg;
 156
 157 Debug (16, "reg = %s\n", unw_regname (reg));
 158   if (!(addr = uc_addr (uc, reg)))
 159     goto badreg;
 160
 161   if (write)
 162     {
 163       *(unw_word_t *) addr = *val;
 164       Debug (12, "%s <- %x\n", unw_regname (reg), *val);
 165     }
 166   else
 167     {
 168       *val = *(unw_word_t *) addr;
 169       Debug (12, "%s -> %x\n", unw_regname (reg), *val);
 170     }
 171   return 0;
 172
 173  badreg:
 174   Debug (1, "bad register number %u\n", reg);
 175   return -UNW_EBADREG;
 176 }
 177
 178 static int
 179 access_fpreg (unw_addr_space_t as, unw_regnum_t reg, unw_fpreg_t *val,
 180               int write, void *arg)
 181 {
 182   unw_tdep_context_t *uc = arg;
 183   unw_fpreg_t *addr;
 184
 185   if (!unw_is_fpreg (reg))
 186     goto badreg;
 187
 188   if (!(addr = uc_addr (uc, reg)))
 189     goto badreg;
 190
 191   if (write)
 192     {
 193       Debug (12, "%s <- %08lx.%08lx.%08lx\n", unw_regname (reg),
 194              ((long *)val)[0], ((long *)val)[1], ((long *)val)[2]);
 195       *(unw_fpreg_t *) addr = *val;
 196     }
 197   else
 198     {
 199       *val = *(unw_fpreg_t *) addr;
 200       Debug (12, "%s -> %08lx.%08lx.%08lx\n", unw_regname (reg),
 201              ((long *)val)[0], ((long *)val)[1], ((long *)val)[2]);
 202     }
 203   return 0;
 204
 205  badreg:
 206   Debug (1, "bad register number %u\n", reg);
 207   /* attempt to access a non-preserved register */
 208   return -UNW_EBADREG;
 209 }
 210
 211 static int
 212 get_static_proc_name (unw_addr_space_t as, unw_word_t ip,
 213                       char *buf, size_t buf_len, unw_word_t *offp,
 214                       void *arg)
 215 {
 216   return _Uelf32_get_proc_name (as, getpid (), ip, buf, buf_len, offp);
 217 }
 218
 219 HIDDEN void
 220 arm_local_addr_space_init (void)
 221 {
 222   memset (&local_addr_space, 0, sizeof (local_addr_space));
 223   local_addr_space.caching_policy = UNW_CACHE_GLOBAL;
 224   local_addr_space.acc.find_proc_info = arm_find_proc_info;
 225   local_addr_space.acc.put_unwind_info = arm_put_unwind_info;
 226   local_addr_space.acc.get_dyn_info_list_addr = get_dyn_info_list_addr;
 227   local_addr_space.acc.access_mem = access_mem;
 228   local_addr_space.acc.access_reg = access_reg;
 229   local_addr_space.acc.access_fpreg = access_fpreg;
 230   local_addr_space.acc.resume = arm_local_resume;
 231   local_addr_space.acc.get_proc_name = get_static_proc_name;
 232   unw_flush_cache (&local_addr_space, 0, 0);
 233 }
 234
 235 #endif /* !UNW_REMOTE_ONLY */