| /* Locate TLS data for a thread. |
| Copyright (C) 2003-2014 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, see |
| <http://www.gnu.org/licenses/>. */ |
| |
| #include "thread_dbP.h" |
| |
| td_err_e |
| td_thr_tlsbase (const td_thrhandle_t *th, |
| unsigned long int modid, |
| psaddr_t *base) |
| { |
| td_err_e err; |
| psaddr_t dtv, dtvslot, dtvptr; |
| |
| if (modid < 1) |
| return TD_NOTLS; |
| |
| psaddr_t pd = th->th_unique; |
| if (pd == 0) |
| { |
| /* This is the fake handle for the main thread before libpthread |
| initialization. We are using 0 for its th_unique because we can't |
| trust that its thread register has been initialized. But we need |
| a real pointer to have any TLS access work. In case of dlopen'd |
| libpthread, initialization might not be for quite some time. So |
| try looking up the thread register now. Worst case, it's nonzero |
| uninitialized garbage and we get bogus results for TLS access |
| attempted too early. Tough. */ |
| |
| td_thrhandle_t main_th; |
| err = __td_ta_lookup_th_unique (th->th_ta_p, ps_getpid (th->th_ta_p->ph), |
| &main_th); |
| if (err == 0) |
| pd = main_th.th_unique; |
| if (pd == 0) |
| return TD_TLSDEFER; |
| } |
| |
| /* Get the DTV pointer from the thread descriptor. */ |
| err = DB_GET_FIELD (dtv, th->th_ta_p, pd, pthread, dtvp, 0); |
| if (err != TD_OK) |
| return err; |
| |
| /* Find the corresponding entry in the DTV. */ |
| err = DB_GET_FIELD_ADDRESS (dtvslot, th->th_ta_p, dtv, dtv, dtv, modid); |
| if (err != TD_OK) |
| return err; |
| |
| /* Extract the TLS block address from that DTV slot. */ |
| err = DB_GET_FIELD (dtvptr, th->th_ta_p, dtvslot, dtv_t, pointer_val, 0); |
| if (err != TD_OK) |
| return err; |
| |
| /* It could be that the memory for this module is not allocated for |
| the given thread. */ |
| if ((uintptr_t) dtvptr & 1) |
| return TD_TLSDEFER; |
| |
| *base = dtvptr; |
| return TD_OK; |
| } |