src/libs/libunwind/os-freebsd.c

   1 /* libunwind - a platform-independent unwind library
   2    Copyright (C) 2010 Konstantin Belousov <kib@freebsd.org>
   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 <sys/param.h>
  26 #include <sys/types.h>
  27 #include <sys/mman.h>
  28 #include <sys/sysctl.h>
  29 #include <sys/user.h>
  30 #include <stdio.h>
  31 #include <errno.h>
  32
  33 #include "libunwind_i.h"
  34
  35 static void *
  36 get_mem(size_t sz)
  37 {
  38   void *res;
  39
  40   res = mmap(NULL, sz, PROT_READ | PROT_WRITE, MAP_ANON | MAP_PRIVATE, -1, 0);
  41   if (res == MAP_FAILED)
  42     return (NULL);
  43   return (res);
  44 }
  45
  46 static void
  47 free_mem(void *ptr, size_t sz)
  48 {
  49   munmap(ptr, sz);
  50 }
  51
  52 static int
  53 get_pid_by_tid(int tid)
  54 {
  55   int mib[3], error;
  56   size_t len, len1;
  57   char *buf;
  58   struct kinfo_proc *kv;
  59   int i, pid;
  60
  61   len = 0;
  62   mib[0] = CTL_KERN;
  63   mib[1] = KERN_PROC;
  64   mib[2] = KERN_PROC_ALL;
  65
  66   error = sysctl(mib, 3, NULL, &len, NULL, 0);
  67   if (error == -1)
  68     return (-1);
  69   len1 = len * 4 / 3;
  70   buf = get_mem(len1);
  71   if (buf == NULL)
  72     return (-1);
  73   len = len1;
  74   error = sysctl(mib, 3, buf, &len, NULL, 0);
  75   if (error == -1) {
  76     free_mem(buf, len1);
  77     return (-1);
  78   }
  79   pid = -1;
  80   for (i = 0, kv = (struct kinfo_proc *)buf; i < len / sizeof(*kv);
  81    i++, kv++) {
  82     if (kv->ki_tid == tid) {
  83       pid = kv->ki_pid;
  84       break;
  85     }
  86   }
  87   free_mem(buf, len1);
  88   return (pid);
  89 }
  90
  91 PROTECTED int
  92 tdep_get_elf_image (struct elf_image *ei, pid_t pid, unw_word_t ip,
  93                     unsigned long *segbase, unsigned long *mapoff, char *path, size_t pathlen)
  94 {
  95   int mib[4], error, ret;
  96   size_t len, len1;
  97   char *buf, *bp, *eb;
  98   struct kinfo_vmentry *kv;
  99
 100   len = 0;
 101   mib[0] = CTL_KERN;
 102   mib[1] = KERN_PROC;
 103   mib[2] = KERN_PROC_VMMAP;
 104   mib[3] = pid;
 105
 106   error = sysctl(mib, 4, NULL, &len, NULL, 0);
 107   if (error == -1) {
 108     if (errno == ESRCH) {
 109       mib[3] = get_pid_by_tid(pid);
 110       if (mib[3] != -1)
 111         error = sysctl(mib, 4, NULL, &len, NULL, 0);
 112       if (error == -1)
 113         return (-UNW_EUNSPEC);
 114     } else
 115       return (-UNW_EUNSPEC);
 116   }
 117   len1 = len * 4 / 3;
 118   buf = get_mem(len1);
 119   if (buf == NULL)
 120     return (-UNW_EUNSPEC);
 121   len = len1;
 122   error = sysctl(mib, 4, buf, &len, NULL, 0);
 123   if (error == -1) {
 124     free_mem(buf, len1);
 125     return (-UNW_EUNSPEC);
 126   }
 127   ret = -UNW_EUNSPEC;
 128   for (bp = buf, eb = buf + len; bp < eb; bp += kv->kve_structsize) {
 129      kv = (struct kinfo_vmentry *)(uintptr_t)bp;
 130      if (ip < kv->kve_start || ip >= kv->kve_end)
 131        continue;
 132      if (kv->kve_type != KVME_TYPE_VNODE)
 133        continue;
 134      *segbase = kv->kve_start;
 135      *mapoff = kv->kve_offset;
 136      if (path)
 137        {
 138          strncpy(path, kv->kve_path, pathlen);
 139        }
 140      ret = elf_map_image (ei, kv->kve_path);
 141      break;
 142   }
 143   free_mem(buf, len1);
 144   return (ret);
 145 }