/* Which thread is running on an LWP? Copyright (C) 2003-2013 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" #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); }