/* * CDDL HEADER START * * The contents of this file are subject to the terms of the * Common Development and Distribution License, Version 1.0 only * (the "License"). You may not use this file except in compliance * with the License. * * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE * or http://www.opensolaris.org/os/licensing. * See the License for the specific language governing permissions * and limitations under the License. * * When distributing Covered Code, include this CDDL HEADER in each * file and include the License file at usr/src/OPENSOLARIS.LICENSE. * If applicable, add the following below this CDDL HEADER, with the * fields enclosed by brackets "[]" replaced with your own identifying * information: Portions Copyright [yyyy] [name of copyright owner] * * CDDL HEADER END */ /* * Copyright (c) 2000-2001 by Sun Microsystems, Inc. * All rights reserved. */ /* * libthread_db (tdb) cache * * In order to properly debug multi-threaded programs, the proc target must be * able to query and modify information such as a thread's register set using * either the native LWP services provided by libproc (if the process is not * linked with libthread), or using the services provided by libthread_db (if * the process is linked with libthread). Additionally, a process may begin * life as a single-threaded process and then later dlopen() libthread, so we * must be prepared to switch modes on-the-fly. There are also two possible * libthread implementations (one in /usr/lib and one in /usr/lib/lwp) so we * cannot link mdb against libthread_db directly; instead, we must dlopen the * appropriate libthread_db on-the-fly based on which libthread.so the victim * process has open. Finally, mdb is designed so that multiple targets can be * active simultaneously, so we could even have *both* libthread_db's open at * the same time. This might happen if you were looking at two multi-threaded * user processes inside of a crash dump, one using /usr/lib/libthread.so and * the other using /usr/lib/lwp/libthread.so. To meet these requirements, we * implement a libthread_db "cache" in this file. The proc target calls * mdb_tdb_load() with the pathname of a libthread_db to load, and if it is * not already open, we dlopen() it, look up the symbols we need to reference, * and fill in an ops vector which we return to the caller. Once an object is * loaded, we don't bother unloading it unless the entire cache is explicitly * flushed. This mechanism also has the nice property that we don't bother * loading libthread_db until we need it, so the debugger starts up faster. */ #include #include #include #include #include #include #include static mdb_tdb_lib_t *tdb_list; static td_err_e tdb_notsup() { return (TD_NOCAPAB); /* return thread_db code for not supported */ } const mdb_tdb_ops_t * mdb_tdb_load(const char *path) { td_err_e (*tdb_init)(void); mdb_tdb_lib_t *t; td_err_e err; void *hdl; /* * Search through the existing cache of thread_db libraries and see if * we have this one loaded already. If so, just return its ops vector. */ for (t = tdb_list; t != NULL; t = t->tdb_next) { if (strcmp(path, t->tdb_pathname) == 0) break; } if (t != NULL) return (&t->tdb_ops); /* * Otherwise dlmopen the new library, look up its td_init() function, * and call it. If any of this fails, we return NULL for failure. */ if (access(path, F_OK) == -1) return (NULL); if ((hdl = dlmopen(LM_ID_BASE, path, RTLD_LAZY | RTLD_LOCAL)) == NULL) { (void) set_errno(EMDB_RTLD); return (NULL); } if ((tdb_init = (td_err_e (*)(void))dlsym(hdl, "td_init")) == NULL) { (void) dlclose(hdl); (void) set_errno(tdb_to_errno(TD_NOCAPAB)); return (NULL); } if ((err = tdb_init()) != TD_OK) { (void) dlclose(hdl); (void) set_errno(tdb_to_errno(err)); return (NULL); } /* * If td_init() succeeds, we can't fail from here on. Allocate a new * library entry and add it to our linked list. */ t = mdb_alloc(sizeof (mdb_tdb_lib_t), UM_SLEEP); (void) strncpy(t->tdb_pathname, path, MAXPATHLEN); t->tdb_pathname[MAXPATHLEN - 1] = '\0'; t->tdb_handle = hdl; t->tdb_next = tdb_list; tdb_list = t; /* * For each function we need to call in the thread_db library, look it * up using dlsym(). If we find it, add it to the ops vector. If not, * put the address of our default function (see above) in that slot. */ t->tdb_ops.td_ta_new = (td_err_e (*)())dlsym(hdl, "td_ta_new"); if (t->tdb_ops.td_ta_new == NULL) t->tdb_ops.td_ta_new = (td_err_e (*)())tdb_notsup; t->tdb_ops.td_ta_delete = (td_err_e (*)())dlsym(hdl, "td_ta_delete"); if (t->tdb_ops.td_ta_delete == NULL) t->tdb_ops.td_ta_delete = (td_err_e (*)())tdb_notsup; t->tdb_ops.td_ta_thr_iter = (td_err_e (*)()) dlsym(hdl, "td_ta_thr_iter"); if (t->tdb_ops.td_ta_thr_iter == NULL) t->tdb_ops.td_ta_thr_iter = (td_err_e (*)())tdb_notsup; t->tdb_ops.td_ta_map_id2thr = (td_err_e (*)()) dlsym(hdl, "td_ta_map_id2thr"); if (t->tdb_ops.td_ta_map_id2thr == NULL) t->tdb_ops.td_ta_map_id2thr = (td_err_e (*)())tdb_notsup; t->tdb_ops.td_ta_map_lwp2thr = (td_err_e (*)()) dlsym(hdl, "td_ta_map_lwp2thr"); if (t->tdb_ops.td_ta_map_lwp2thr == NULL) t->tdb_ops.td_ta_map_lwp2thr = (td_err_e (*)())tdb_notsup; t->tdb_ops.td_thr_get_info = (td_err_e (*)()) dlsym(hdl, "td_thr_get_info"); if (t->tdb_ops.td_thr_get_info == NULL) t->tdb_ops.td_thr_get_info = (td_err_e (*)())tdb_notsup; t->tdb_ops.td_thr_getgregs = (td_err_e (*)()) dlsym(hdl, "td_thr_getgregs"); if (t->tdb_ops.td_thr_getgregs == NULL) t->tdb_ops.td_thr_getgregs = (td_err_e (*)())tdb_notsup; t->tdb_ops.td_thr_setgregs = (td_err_e (*)()) dlsym(hdl, "td_thr_setgregs"); if (t->tdb_ops.td_thr_setgregs == NULL) t->tdb_ops.td_thr_setgregs = (td_err_e (*)())tdb_notsup; t->tdb_ops.td_thr_getfpregs = (td_err_e (*)()) dlsym(hdl, "td_thr_getfpregs"); if (t->tdb_ops.td_thr_getfpregs == NULL) t->tdb_ops.td_thr_getfpregs = (td_err_e (*)())tdb_notsup; t->tdb_ops.td_thr_setfpregs = (td_err_e (*)()) dlsym(hdl, "td_thr_setfpregs"); if (t->tdb_ops.td_thr_setfpregs == NULL) t->tdb_ops.td_thr_setfpregs = (td_err_e (*)())tdb_notsup; t->tdb_ops.td_thr_tlsbase = (td_err_e (*)()) dlsym(hdl, "td_thr_tlsbase"); if (t->tdb_ops.td_thr_tlsbase == NULL) t->tdb_ops.td_thr_tlsbase = (td_err_e (*)())tdb_notsup; t->tdb_ops.td_thr_getxregsize = (td_err_e (*)()) dlsym(hdl, "td_thr_getxregsize"); if (t->tdb_ops.td_thr_getxregsize == NULL) t->tdb_ops.td_thr_getxregsize = (td_err_e (*)())tdb_notsup; t->tdb_ops.td_thr_getxregs = (td_err_e (*)()) dlsym(hdl, "td_thr_getxregs"); if (t->tdb_ops.td_thr_getxregs == NULL) t->tdb_ops.td_thr_getxregs = (td_err_e (*)())tdb_notsup; t->tdb_ops.td_thr_setxregs = (td_err_e (*)()) dlsym(hdl, "td_thr_setxregs"); if (t->tdb_ops.td_thr_setxregs == NULL) t->tdb_ops.td_thr_setxregs = (td_err_e (*)())tdb_notsup; return (&t->tdb_ops); } void mdb_tdb_flush(void) { mdb_tdb_lib_t *t, *u; for (t = tdb_list; t != NULL; t = u) { u = t->tdb_next; (void) dlclose(t->tdb_handle); mdb_free(t, sizeof (mdb_tdb_lib_t)); } tdb_list = NULL; }