about summary refs log tree commit diff
path: root/nptl_db/td_ta_map_lwp2thr.c
blob: 4835f31f948048856425db659bfa04b96552e623 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
/* Which thread is running on an LWP?
   Copyright (C) 2003,2004,2007,2009 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, write to the Free
   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   02111-1307 USA.  */

#include "thread_dbP.h"
#include <stdlib.h>
#include <byteswap.h>
#include <sys/procfs.h>


td_err_e
__td_ta_lookup_th_unique (const td_thragent_t *ta_arg,
			  lwpid_t lwpid, td_thrhandle_t *th)
{
  td_thragent_t *const ta = (td_thragent_t *) ta_arg;
  ps_err_e err;
  td_err_e terr;
  prgregset_t regs;
  psaddr_t addr;

  if (ta->ta_howto == ta_howto_unknown)
    {
      /* We need to read in from the inferior the instructions what to do.  */
      psaddr_t howto;

      err = td_lookup (ta->ph, SYM_TH_UNIQUE_CONST_THREAD_AREA, &howto);
      if (err == PS_OK)
	{
	  err = ps_pdread (ta->ph, howto,
			   &ta->ta_howto_data.const_thread_area,
 			   sizeof ta->ta_howto_data.const_thread_area);
	  if (err != PS_OK)
	    return TD_ERR;
	  ta->ta_howto = ta_howto_const_thread_area;
	  if (ta->ta_howto_data.const_thread_area & 0xff000000U)
	    ta->ta_howto_data.const_thread_area
	      = bswap_32 (ta->ta_howto_data.const_thread_area);
	}
      else
	{
	  switch (sizeof (regs[0]))
	    {
	    case 8:
	      err = td_lookup (ta->ph, SYM_TH_UNIQUE_REGISTER64, &howto);
	      if (err == PS_OK)
		ta->ta_howto = ta_howto_reg;
	      else if (err == PS_NOSYM)
		{
		  err = td_lookup (ta->ph,
				   SYM_TH_UNIQUE_REGISTER64_THREAD_AREA,
				   &howto);
		  if (err == PS_OK)
		    ta->ta_howto = ta_howto_reg_thread_area;
		}
	      break;

	    case 4:
	      err = td_lookup (ta->ph, SYM_TH_UNIQUE_REGISTER32, &howto);
	      if (err == PS_OK)
		ta->ta_howto = ta_howto_reg;
	      else if (err == PS_NOSYM)
		{
		  err = td_lookup (ta->ph,
				   SYM_TH_UNIQUE_REGISTER32_THREAD_AREA,
				   &howto);
		  if (err == PS_OK)
		    ta->ta_howto = ta_howto_reg_thread_area;
		}
	      break;

	    default:
	      abort ();
	      return TD_DBERR;
	    }

	  if (err != PS_OK)
	    return TD_DBERR;

	  /* For either of these methods we read in the same descriptor.  */
	  err = ps_pdread (ta->ph, howto,
			   ta->ta_howto_data.reg, DB_SIZEOF_DESC);
	  if (err != PS_OK)
	    return TD_ERR;
	  if (DB_DESC_SIZE (ta->ta_howto_data.reg) == 0)
	    return TD_DBERR;
	  if (DB_DESC_SIZE (ta->ta_howto_data.reg) & 0xff000000U)
	    {
	      /* Byte-swap these words, though we leave the size word
		 in native order as the handy way to distinguish.  */
	      DB_DESC_OFFSET (ta->ta_howto_data.reg)
		= bswap_32 (DB_DESC_OFFSET (ta->ta_howto_data.reg));
	      DB_DESC_NELEM (ta->ta_howto_data.reg)
		= bswap_32 (DB_DESC_NELEM (ta->ta_howto_data.reg));
	    }
	}
    }

  switch (ta->ta_howto)
    {
    default:
      return TD_DBERR;

    case ta_howto_reg:
      /* On most machines, we are just looking at a register.  */
      if (ps_lgetregs (ta->ph, lwpid, regs) != PS_OK)
	return TD_ERR;
      terr = _td_fetch_value_local (ta, ta->ta_howto_data.reg, -1,
				    0, regs, &addr);
      if (terr != TD_OK)
	return terr;

      /* In this descriptor the nelem word is overloaded as the bias.  */
      addr += (int32_t) DB_DESC_NELEM (ta->ta_howto_data.reg);
      th->th_unique = addr;
      break;

    case ta_howto_const_thread_area:
      /* Some hosts don't have this call and this case won't be used.  */
# pragma weak ps_get_thread_area
      if (&ps_get_thread_area == NULL)
	return TD_NOCAPAB;

      /* A la x86-64, there is a magic index for get_thread_area.  */
      if (ps_get_thread_area (ta->ph, lwpid,
			      ta->ta_howto_data.const_thread_area,
			      &th->th_unique) != PS_OK)
	return TD_ERR;	/* XXX Other error value?  */
      break;

    case ta_howto_reg_thread_area:
      if (&ps_get_thread_area == NULL)
	return TD_NOCAPAB;

      /* A la i386, a register holds the index for get_thread_area.  */
      if (ps_lgetregs (ta->ph, lwpid, regs) != PS_OK)
	return TD_ERR;
      terr = _td_fetch_value_local (ta, ta->ta_howto_data.reg_thread_area,
				    -1, 0, regs, &addr);
      if (terr != TD_OK)
	return terr;
      /* In this descriptor the nelem word is overloaded as scale factor.  */
      if (ps_get_thread_area
	  (ta->ph, lwpid,
	   ((addr - (psaddr_t) 0)
	    >> DB_DESC_NELEM (ta->ta_howto_data.reg_thread_area)),
	   &th->th_unique) != PS_OK)
	return TD_ERR;	/* XXX Other error value?  */
      break;
    }

  /* Found it.  Now complete the `td_thrhandle_t' object.  */
  th->th_ta_p = ta;

  return TD_OK;
}

td_err_e
td_ta_map_lwp2thr (const td_thragent_t *ta_arg,
		   lwpid_t lwpid, td_thrhandle_t *th)
{
  td_thragent_t *const ta = (td_thragent_t *) ta_arg;

  LOG ("td_ta_map_lwp2thr");

  /* Test whether the TA parameter is ok.  */
  if (! ta_ok (ta))
    return TD_BADTA;

  /* We cannot rely on thread registers and such information at all
     before __pthread_initialize_minimal has gotten far enough.  They
     sometimes contain garbage that would confuse us, left by the kernel
     at exec.  So if it looks like initialization is incomplete, we only
     fake a special descriptor for the initial thread.  */

  psaddr_t list;
  td_err_e err = DB_GET_SYMBOL (list, ta, __stack_user);
  if (err != TD_OK)
    return err;

  err = DB_GET_FIELD (list, ta, list, list_t, next, 0);
  if (err != TD_OK)
    return err;

  if (list == 0)
    {
      if (ps_getpid (ta->ph) != lwpid)
	return TD_ERR;
      th->th_ta_p = ta;
      th->th_unique = 0;
      return TD_OK;
    }

  return __td_ta_lookup_th_unique (ta_arg, lwpid, th);
}