123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367368369370371372373374375376377378379380381382383384385386387388389390391392393394395396397398399400401402403404405406407408409410411412413414415416417418419420421422423424425426427428429430431432433434435436437438439440441442443444445446447448449450451452453454455456457458459460461462463464465466467468469470471472473474475476477478479480481482483484485486487488489490491492493494495496497498499500501502503504505506507508509510511512513514515516517518519520521522523524525526527528529530531532533534535536537538539540541542543544545546547548549550551552553554555556557558559560561562563564565566567568569570571572573574575576577578579580581582583584585586587588589590591592593594595596597598599600601602603604605606607608609610611612613614615616617618619620621622623624625626627628629630631632633634635636637638639640641642643644645646647648649650651652653654655656657658659660661662663664665666667668669670671672673674675676677678679680681682683684685686687688689690691692693694695696697698699700701702703704705706707708709710711712713714715716717718719720721722723724725726727728729730731732733734735736737738739740741742743744745746747748749750751752753754755756757758759760761762763764765766767768769770771772773774775776777778779780781782783784785786787788789790791792793794795796797798799800801802803804805806807808809810811812813814815816817818819820821822823824825826827828829830831832833834835836837838839840841842843844845846847848849850851852853854855856857858859860861862863864865866867868869870871872873874875876877878879880881882883884885886887888 |
- /* Thread management interface, for the remote server for GDB.
- Copyright (C) 2002-2022 Free Software Foundation, Inc.
- Contributed by MontaVista Software.
- This file is part of GDB.
- This program is free software; you can redistribute it and/or modify
- it under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 3 of the License, or
- (at your option) any later version.
- This program 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 General Public License for more details.
- You should have received a copy of the GNU General Public License
- along with this program. If not, see <http://www.gnu.org/licenses/>. */
- #include "server.h"
- #include "linux-low.h"
- #include "debug.h"
- #include "gdb_proc_service.h"
- #include "nat/gdb_thread_db.h"
- #include "gdbsupport/gdb_vecs.h"
- #include "nat/linux-procfs.h"
- #include "gdbsupport/scoped_restore.h"
- #ifndef USE_LIBTHREAD_DB_DIRECTLY
- #include <dlfcn.h>
- #endif
- #include <limits.h>
- #include <ctype.h>
- struct thread_db
- {
- /* Structure that identifies the child process for the
- <proc_service.h> interface. */
- struct ps_prochandle proc_handle;
- /* Connection to the libthread_db library. */
- td_thragent_t *thread_agent;
- /* If this flag has been set, we've already asked GDB for all
- symbols we might need; assume symbol cache misses are
- failures. */
- int all_symbols_looked_up;
- #ifndef USE_LIBTHREAD_DB_DIRECTLY
- /* Handle of the libthread_db from dlopen. */
- void *handle;
- #endif
- /* Addresses of libthread_db functions. */
- td_ta_new_ftype *td_ta_new_p;
- td_ta_map_lwp2thr_ftype *td_ta_map_lwp2thr_p;
- td_thr_get_info_ftype *td_thr_get_info_p;
- td_ta_thr_iter_ftype *td_ta_thr_iter_p;
- td_thr_tls_get_addr_ftype *td_thr_tls_get_addr_p;
- td_thr_tlsbase_ftype *td_thr_tlsbase_p;
- td_symbol_list_ftype *td_symbol_list_p;
- };
- static char *libthread_db_search_path;
- static int find_one_thread (ptid_t);
- static int find_new_threads_callback (const td_thrhandle_t *th_p, void *data);
- static const char *
- thread_db_err_str (td_err_e err)
- {
- static char buf[64];
- switch (err)
- {
- case TD_OK:
- return "generic 'call succeeded'";
- case TD_ERR:
- return "generic error";
- case TD_NOTHR:
- return "no thread to satisfy query";
- case TD_NOSV:
- return "no sync handle to satisfy query";
- case TD_NOLWP:
- return "no LWP to satisfy query";
- case TD_BADPH:
- return "invalid process handle";
- case TD_BADTH:
- return "invalid thread handle";
- case TD_BADSH:
- return "invalid synchronization handle";
- case TD_BADTA:
- return "invalid thread agent";
- case TD_BADKEY:
- return "invalid key";
- case TD_NOMSG:
- return "no event message for getmsg";
- case TD_NOFPREGS:
- return "FPU register set not available";
- case TD_NOLIBTHREAD:
- return "application not linked with libthread";
- case TD_NOEVENT:
- return "requested event is not supported";
- case TD_NOCAPAB:
- return "capability not available";
- case TD_DBERR:
- return "debugger service failed";
- case TD_NOAPLIC:
- return "operation not applicable to";
- case TD_NOTSD:
- return "no thread-specific data for this thread";
- case TD_MALLOC:
- return "malloc failed";
- case TD_PARTIALREG:
- return "only part of register set was written/read";
- case TD_NOXREGS:
- return "X register set not available for this thread";
- #ifdef HAVE_TD_VERSION
- case TD_VERSION:
- return "version mismatch between libthread_db and libpthread";
- #endif
- default:
- xsnprintf (buf, sizeof (buf), "unknown thread_db error '%d'", err);
- return buf;
- }
- }
- #if 0
- static char *
- thread_db_state_str (td_thr_state_e state)
- {
- static char buf[64];
- switch (state)
- {
- case TD_THR_STOPPED:
- return "stopped by debugger";
- case TD_THR_RUN:
- return "runnable";
- case TD_THR_ACTIVE:
- return "active";
- case TD_THR_ZOMBIE:
- return "zombie";
- case TD_THR_SLEEP:
- return "sleeping";
- case TD_THR_STOPPED_ASLEEP:
- return "stopped by debugger AND blocked";
- default:
- xsnprintf (buf, sizeof (buf), "unknown thread_db state %d", state);
- return buf;
- }
- }
- #endif
- /* Get thread info about PTID, accessing memory via the current
- thread. */
- static int
- find_one_thread (ptid_t ptid)
- {
- td_thrhandle_t th;
- td_thrinfo_t ti;
- td_err_e err;
- struct lwp_info *lwp;
- struct thread_db *thread_db = current_process ()->priv->thread_db;
- int lwpid = ptid.lwp ();
- thread_info *thread = find_thread_ptid (ptid);
- lwp = get_thread_lwp (thread);
- if (lwp->thread_known)
- return 1;
- /* Get information about this thread. */
- err = thread_db->td_ta_map_lwp2thr_p (thread_db->thread_agent, lwpid, &th);
- if (err != TD_OK)
- error ("Cannot get thread handle for LWP %d: %s",
- lwpid, thread_db_err_str (err));
- err = thread_db->td_thr_get_info_p (&th, &ti);
- if (err != TD_OK)
- error ("Cannot get thread info for LWP %d: %s",
- lwpid, thread_db_err_str (err));
- threads_debug_printf ("Found thread %ld (LWP %d)",
- (unsigned long) ti.ti_tid, ti.ti_lid);
- if (lwpid != ti.ti_lid)
- {
- warning ("PID mismatch! Expected %ld, got %ld",
- (long) lwpid, (long) ti.ti_lid);
- return 0;
- }
- /* If the new thread ID is zero, a final thread ID will be available
- later. Do not enable thread debugging yet. */
- if (ti.ti_tid == 0)
- return 0;
- lwp->thread_known = 1;
- lwp->th = th;
- lwp->thread_handle = ti.ti_tid;
- return 1;
- }
- /* Attach a thread. Return true on success. */
- static int
- attach_thread (const td_thrhandle_t *th_p, td_thrinfo_t *ti_p)
- {
- struct process_info *proc = current_process ();
- int pid = pid_of (proc);
- ptid_t ptid = ptid_t (pid, ti_p->ti_lid);
- struct lwp_info *lwp;
- int err;
- threads_debug_printf ("Attaching to thread %ld (LWP %d)",
- (unsigned long) ti_p->ti_tid, ti_p->ti_lid);
- err = the_linux_target->attach_lwp (ptid);
- if (err != 0)
- {
- std::string reason = linux_ptrace_attach_fail_reason_string (ptid, err);
- warning ("Could not attach to thread %ld (LWP %d): %s",
- (unsigned long) ti_p->ti_tid, ti_p->ti_lid, reason.c_str ());
- return 0;
- }
- lwp = find_lwp_pid (ptid);
- gdb_assert (lwp != NULL);
- lwp->thread_known = 1;
- lwp->th = *th_p;
- lwp->thread_handle = ti_p->ti_tid;
- return 1;
- }
- /* Attach thread if we haven't seen it yet.
- Increment *COUNTER if we have attached a new thread.
- Return false on failure. */
- static int
- maybe_attach_thread (const td_thrhandle_t *th_p, td_thrinfo_t *ti_p,
- int *counter)
- {
- struct lwp_info *lwp;
- lwp = find_lwp_pid (ptid_t (ti_p->ti_lid));
- if (lwp != NULL)
- return 1;
- if (!attach_thread (th_p, ti_p))
- return 0;
- if (counter != NULL)
- *counter += 1;
- return 1;
- }
- static int
- find_new_threads_callback (const td_thrhandle_t *th_p, void *data)
- {
- td_thrinfo_t ti;
- td_err_e err;
- struct thread_db *thread_db = current_process ()->priv->thread_db;
- err = thread_db->td_thr_get_info_p (th_p, &ti);
- if (err != TD_OK)
- error ("Cannot get thread info: %s", thread_db_err_str (err));
- if (ti.ti_lid == -1)
- {
- /* A thread with kernel thread ID -1 is either a thread that
- exited and was joined, or a thread that is being created but
- hasn't started yet, and that is reusing the tcb/stack of a
- thread that previously exited and was joined. (glibc marks
- terminated and joined threads with kernel thread ID -1. See
- glibc PR17707. */
- threads_debug_printf ("thread_db: skipping exited and "
- "joined thread (0x%lx)",
- (unsigned long) ti.ti_tid);
- return 0;
- }
- /* Check for zombies. */
- if (ti.ti_state == TD_THR_UNKNOWN || ti.ti_state == TD_THR_ZOMBIE)
- return 0;
- if (!maybe_attach_thread (th_p, &ti, (int *) data))
- {
- /* Terminate iteration early: we might be looking at stale data in
- the inferior. The thread_db_find_new_threads will retry. */
- return 1;
- }
- return 0;
- }
- static void
- thread_db_find_new_threads (void)
- {
- td_err_e err;
- ptid_t ptid = current_ptid;
- struct thread_db *thread_db = current_process ()->priv->thread_db;
- int loop, iteration;
- /* This function is only called when we first initialize thread_db.
- First locate the initial thread. If it is not ready for
- debugging yet, then stop. */
- if (find_one_thread (ptid) == 0)
- return;
- /* Require 4 successive iterations which do not find any new threads.
- The 4 is a heuristic: there is an inherent race here, and I have
- seen that 2 iterations in a row are not always sufficient to
- "capture" all threads. */
- for (loop = 0, iteration = 0; loop < 4; ++loop, ++iteration)
- {
- int new_thread_count = 0;
- /* Iterate over all user-space threads to discover new threads. */
- err = thread_db->td_ta_thr_iter_p (thread_db->thread_agent,
- find_new_threads_callback,
- &new_thread_count,
- TD_THR_ANY_STATE,
- TD_THR_LOWEST_PRIORITY,
- TD_SIGNO_MASK, TD_THR_ANY_USER_FLAGS);
- threads_debug_printf ("Found %d threads in iteration %d.",
- new_thread_count, iteration);
- if (new_thread_count != 0)
- {
- /* Found new threads. Restart iteration from beginning. */
- loop = -1;
- }
- }
- if (err != TD_OK)
- error ("Cannot find new threads: %s", thread_db_err_str (err));
- }
- /* Cache all future symbols that thread_db might request. We can not
- request symbols at arbitrary states in the remote protocol, only
- when the client tells us that new symbols are available. So when
- we load the thread library, make sure to check the entire list. */
- static void
- thread_db_look_up_symbols (void)
- {
- struct thread_db *thread_db = current_process ()->priv->thread_db;
- const char **sym_list;
- CORE_ADDR unused;
- for (sym_list = thread_db->td_symbol_list_p (); *sym_list; sym_list++)
- look_up_one_symbol (*sym_list, &unused, 1);
- /* We're not interested in any other libraries loaded after this
- point, only in symbols in libpthread.so. */
- thread_db->all_symbols_looked_up = 1;
- }
- int
- thread_db_look_up_one_symbol (const char *name, CORE_ADDR *addrp)
- {
- struct thread_db *thread_db = current_process ()->priv->thread_db;
- int may_ask_gdb = !thread_db->all_symbols_looked_up;
- /* If we've passed the call to thread_db_look_up_symbols, then
- anything not in the cache must not exist; we're not interested
- in any libraries loaded after that point, only in symbols in
- libpthread.so. It might not be an appropriate time to look
- up a symbol, e.g. while we're trying to fetch registers. */
- return look_up_one_symbol (name, addrp, may_ask_gdb);
- }
- int
- thread_db_get_tls_address (struct thread_info *thread, CORE_ADDR offset,
- CORE_ADDR load_module, CORE_ADDR *address)
- {
- psaddr_t addr;
- td_err_e err;
- struct lwp_info *lwp;
- struct process_info *proc;
- struct thread_db *thread_db;
- proc = get_thread_process (thread);
- thread_db = proc->priv->thread_db;
- /* If the thread layer is not (yet) initialized, fail. */
- if (thread_db == NULL || !thread_db->all_symbols_looked_up)
- return TD_ERR;
- /* If td_thr_tls_get_addr is missing rather do not expect td_thr_tlsbase
- could work. */
- if (thread_db->td_thr_tls_get_addr_p == NULL
- || (load_module == 0 && thread_db->td_thr_tlsbase_p == NULL))
- return -1;
- lwp = get_thread_lwp (thread);
- if (!lwp->thread_known)
- find_one_thread (thread->id);
- if (!lwp->thread_known)
- return TD_NOTHR;
- scoped_restore_current_thread restore_thread;
- switch_to_thread (thread);
- if (load_module != 0)
- {
- /* Note the cast through uintptr_t: this interface only works if
- a target address fits in a psaddr_t, which is a host pointer.
- So a 32-bit debugger can not access 64-bit TLS through this. */
- err = thread_db->td_thr_tls_get_addr_p (&lwp->th,
- (psaddr_t) (uintptr_t) load_module,
- offset, &addr);
- }
- else
- {
- /* This code path handles the case of -static -pthread executables:
- https://sourceware.org/ml/libc-help/2014-03/msg00024.html
- For older GNU libc r_debug.r_map is NULL. For GNU libc after
- PR libc/16831 due to GDB PR threads/16954 LOAD_MODULE is also NULL.
- The constant number 1 depends on GNU __libc_setup_tls
- initialization of l_tls_modid to 1. */
- err = thread_db->td_thr_tlsbase_p (&lwp->th, 1, &addr);
- addr = (char *) addr + offset;
- }
- if (err == TD_OK)
- {
- *address = (CORE_ADDR) (uintptr_t) addr;
- return 0;
- }
- else
- return err;
- }
- /* See linux-low.h. */
- bool
- thread_db_thread_handle (ptid_t ptid, gdb_byte **handle, int *handle_len)
- {
- struct thread_db *thread_db;
- struct lwp_info *lwp;
- thread_info *thread = find_thread_ptid (ptid);
- if (thread == NULL)
- return false;
- thread_db = get_thread_process (thread)->priv->thread_db;
- if (thread_db == NULL)
- return false;
- lwp = get_thread_lwp (thread);
- if (!lwp->thread_known && !find_one_thread (thread->id))
- return false;
- gdb_assert (lwp->thread_known);
- *handle = (gdb_byte *) &lwp->thread_handle;
- *handle_len = sizeof (lwp->thread_handle);
- return true;
- }
- #ifdef USE_LIBTHREAD_DB_DIRECTLY
- static int
- thread_db_load_search (void)
- {
- td_err_e err;
- struct thread_db *tdb;
- struct process_info *proc = current_process ();
- gdb_assert (proc->priv->thread_db == NULL);
- tdb = XCNEW (struct thread_db);
- proc->priv->thread_db = tdb;
- tdb->td_ta_new_p = &td_ta_new;
- /* Attempt to open a connection to the thread library. */
- err = tdb->td_ta_new_p (&tdb->proc_handle, &tdb->thread_agent);
- if (err != TD_OK)
- {
- threads_debug_printf ("td_ta_new(): %s", thread_db_err_str (err));
- free (tdb);
- proc->priv->thread_db = NULL;
- return 0;
- }
- tdb->td_ta_map_lwp2thr_p = &td_ta_map_lwp2thr;
- tdb->td_thr_get_info_p = &td_thr_get_info;
- tdb->td_ta_thr_iter_p = &td_ta_thr_iter;
- tdb->td_symbol_list_p = &td_symbol_list;
- /* These are not essential. */
- tdb->td_thr_tls_get_addr_p = &td_thr_tls_get_addr;
- tdb->td_thr_tlsbase_p = &td_thr_tlsbase;
- return 1;
- }
- #else
- static int
- try_thread_db_load_1 (void *handle)
- {
- td_err_e err;
- struct thread_db *tdb;
- struct process_info *proc = current_process ();
- gdb_assert (proc->priv->thread_db == NULL);
- tdb = XCNEW (struct thread_db);
- proc->priv->thread_db = tdb;
- tdb->handle = handle;
- /* Initialize pointers to the dynamic library functions we will use.
- Essential functions first. */
- #define CHK(required, a) \
- do \
- { \
- if ((a) == NULL) \
- { \
- threads_debug_printf ("dlsym: %s", dlerror ()); \
- if (required) \
- { \
- free (tdb); \
- proc->priv->thread_db = NULL; \
- return 0; \
- } \
- } \
- } \
- while (0)
- #define TDB_DLSYM(tdb, func) \
- tdb->func ## _p = (func ## _ftype *) dlsym (tdb->handle, #func)
- CHK (1, TDB_DLSYM (tdb, td_ta_new));
- /* Attempt to open a connection to the thread library. */
- err = tdb->td_ta_new_p (&tdb->proc_handle, &tdb->thread_agent);
- if (err != TD_OK)
- {
- threads_debug_printf ("td_ta_new(): %s", thread_db_err_str (err));
- free (tdb);
- proc->priv->thread_db = NULL;
- return 0;
- }
- CHK (1, TDB_DLSYM (tdb, td_ta_map_lwp2thr));
- CHK (1, TDB_DLSYM (tdb, td_thr_get_info));
- CHK (1, TDB_DLSYM (tdb, td_ta_thr_iter));
- CHK (1, TDB_DLSYM (tdb, td_symbol_list));
- /* These are not essential. */
- CHK (0, TDB_DLSYM (tdb, td_thr_tls_get_addr));
- CHK (0, TDB_DLSYM (tdb, td_thr_tlsbase));
- #undef CHK
- #undef TDB_DLSYM
- return 1;
- }
- #ifdef HAVE_DLADDR
- /* Lookup a library in which given symbol resides.
- Note: this is looking in the GDBSERVER process, not in the inferior.
- Returns library name, or NULL. */
- static const char *
- dladdr_to_soname (const void *addr)
- {
- Dl_info info;
- if (dladdr (addr, &info) != 0)
- return info.dli_fname;
- return NULL;
- }
- #endif
- static int
- try_thread_db_load (const char *library)
- {
- void *handle;
- threads_debug_printf ("Trying host libthread_db library: %s.",
- library);
- handle = dlopen (library, RTLD_NOW);
- if (handle == NULL)
- {
- threads_debug_printf ("dlopen failed: %s.", dlerror ());
- return 0;
- }
- #ifdef HAVE_DLADDR
- if (debug_threads && strchr (library, '/') == NULL)
- {
- void *td_init;
- td_init = dlsym (handle, "td_init");
- if (td_init != NULL)
- {
- const char *const libpath = dladdr_to_soname (td_init);
- if (libpath != NULL)
- threads_debug_printf ("Host %s resolved to: %s.", library, libpath);
- }
- }
- #endif
- if (try_thread_db_load_1 (handle))
- return 1;
- /* This library "refused" to work on current inferior. */
- dlclose (handle);
- return 0;
- }
- /* Handle $sdir in libthread-db-search-path.
- Look for libthread_db in the system dirs, or wherever a plain
- dlopen(file_without_path) will look.
- The result is true for success. */
- static int
- try_thread_db_load_from_sdir (void)
- {
- return try_thread_db_load (LIBTHREAD_DB_SO);
- }
- /* Try to load libthread_db from directory DIR of length DIR_LEN.
- The result is true for success. */
- static int
- try_thread_db_load_from_dir (const char *dir, size_t dir_len)
- {
- char path[PATH_MAX];
- if (dir_len + 1 + strlen (LIBTHREAD_DB_SO) + 1 > sizeof (path))
- {
- char *cp = (char *) xmalloc (dir_len + 1);
- memcpy (cp, dir, dir_len);
- cp[dir_len] = '\0';
- warning (_("libthread-db-search-path component too long,"
- " ignored: %s."), cp);
- free (cp);
- return 0;
- }
- memcpy (path, dir, dir_len);
- path[dir_len] = '/';
- strcpy (path + dir_len + 1, LIBTHREAD_DB_SO);
- return try_thread_db_load (path);
- }
- /* Search libthread_db_search_path for libthread_db which "agrees"
- to work on current inferior.
- The result is true for success. */
- static int
- thread_db_load_search (void)
- {
- int rc = 0;
- if (libthread_db_search_path == NULL)
- libthread_db_search_path = xstrdup (LIBTHREAD_DB_SEARCH_PATH);
- std::vector<gdb::unique_xmalloc_ptr<char>> dir_vec
- = dirnames_to_char_ptr_vec (libthread_db_search_path);
- for (const gdb::unique_xmalloc_ptr<char> &this_dir_up : dir_vec)
- {
- char *this_dir = this_dir_up.get ();
- const int pdir_len = sizeof ("$pdir") - 1;
- size_t this_dir_len;
- this_dir_len = strlen (this_dir);
- if (strncmp (this_dir, "$pdir", pdir_len) == 0
- && (this_dir[pdir_len] == '\0'
- || this_dir[pdir_len] == '/'))
- {
- /* We don't maintain a list of loaded libraries so we don't know
- where libpthread lives. We *could* fetch the info, but we don't
- do that yet. Ignore it. */
- }
- else if (strcmp (this_dir, "$sdir") == 0)
- {
- if (try_thread_db_load_from_sdir ())
- {
- rc = 1;
- break;
- }
- }
- else
- {
- if (try_thread_db_load_from_dir (this_dir, this_dir_len))
- {
- rc = 1;
- break;
- }
- }
- }
- threads_debug_printf ("thread_db_load_search returning %d", rc);
- return rc;
- }
- #endif /* USE_LIBTHREAD_DB_DIRECTLY */
- int
- thread_db_init (void)
- {
- struct process_info *proc = current_process ();
- /* FIXME drow/2004-10-16: This is the "overall process ID", which
- GNU/Linux calls tgid, "thread group ID". When we support
- attaching to threads, the original thread may not be the correct
- thread. We would have to get the process ID from /proc for NPTL.
- This isn't the only place in gdbserver that assumes that the first
- process in the list is the thread group leader. */
- if (thread_db_load_search ())
- {
- /* It's best to avoid td_ta_thr_iter if possible. That walks
- data structures in the inferior's address space that may be
- corrupted, or, if the target is running, the list may change
- while we walk it. In the latter case, it's possible that a
- thread exits just at the exact time that causes GDBserver to
- get stuck in an infinite loop. As the kernel supports clone
- events and /proc/PID/task/ exists, then we already know about
- all threads in the process. When we need info out of
- thread_db on a given thread (e.g., for TLS), we'll use
- find_one_thread then. That uses thread_db entry points that
- do not walk libpthread's thread list, so should be safe, as
- well as more efficient. */
- if (!linux_proc_task_list_dir_exists (pid_of (proc)))
- thread_db_find_new_threads ();
- thread_db_look_up_symbols ();
- return 1;
- }
- return 0;
- }
- /* Disconnect from libthread_db and free resources. */
- static void
- disable_thread_event_reporting (struct process_info *proc)
- {
- struct thread_db *thread_db = proc->priv->thread_db;
- if (thread_db)
- {
- td_err_e (*td_ta_clear_event_p) (const td_thragent_t *ta,
- td_thr_events_t *event);
- #ifndef USE_LIBTHREAD_DB_DIRECTLY
- td_ta_clear_event_p
- = (td_ta_clear_event_ftype *) dlsym (thread_db->handle,
- "td_ta_clear_event");
- #else
- td_ta_clear_event_p = &td_ta_clear_event;
- #endif
- if (td_ta_clear_event_p != NULL)
- {
- scoped_restore_current_thread restore_thread;
- td_thr_events_t events;
- switch_to_process (proc);
- /* Set the process wide mask saying we aren't interested
- in any events anymore. */
- td_event_fillset (&events);
- (*td_ta_clear_event_p) (thread_db->thread_agent, &events);
- }
- }
- }
- void
- thread_db_detach (struct process_info *proc)
- {
- struct thread_db *thread_db = proc->priv->thread_db;
- if (thread_db)
- {
- disable_thread_event_reporting (proc);
- }
- }
- /* Disconnect from libthread_db and free resources. */
- void
- thread_db_mourn (struct process_info *proc)
- {
- struct thread_db *thread_db = proc->priv->thread_db;
- if (thread_db)
- {
- td_ta_delete_ftype *td_ta_delete_p;
- #ifndef USE_LIBTHREAD_DB_DIRECTLY
- td_ta_delete_p = (td_ta_delete_ftype *) dlsym (thread_db->handle, "td_ta_delete");
- #else
- td_ta_delete_p = &td_ta_delete;
- #endif
- if (td_ta_delete_p != NULL)
- (*td_ta_delete_p) (thread_db->thread_agent);
- #ifndef USE_LIBTHREAD_DB_DIRECTLY
- dlclose (thread_db->handle);
- #endif /* USE_LIBTHREAD_DB_DIRECTLY */
- free (thread_db);
- proc->priv->thread_db = NULL;
- }
- }
- /* Handle "set libthread-db-search-path" monitor command and return 1.
- For any other command, return 0. */
- int
- thread_db_handle_monitor_command (char *mon)
- {
- const char *cmd = "set libthread-db-search-path";
- size_t cmd_len = strlen (cmd);
- if (strncmp (mon, cmd, cmd_len) == 0
- && (mon[cmd_len] == '\0'
- || mon[cmd_len] == ' '))
- {
- const char *cp = mon + cmd_len;
- if (libthread_db_search_path != NULL)
- free (libthread_db_search_path);
- /* Skip leading space (if any). */
- while (isspace (*cp))
- ++cp;
- if (*cp == '\0')
- cp = LIBTHREAD_DB_SEARCH_PATH;
- libthread_db_search_path = xstrdup (cp);
- monitor_output ("libthread-db-search-path set to `");
- monitor_output (libthread_db_search_path);
- monitor_output ("'\n");
- return 1;
- }
- /* Tell server.c to perform default processing. */
- return 0;
- }
- /* See linux-low.h. */
- void
- thread_db_notice_clone (struct thread_info *parent_thr, ptid_t child_ptid)
- {
- process_info *parent_proc = get_thread_process (parent_thr);
- struct thread_db *thread_db = parent_proc->priv->thread_db;
- /* If the thread layer isn't initialized, return. It may just
- be that the program uses clone, but does not use libthread_db. */
- if (thread_db == NULL || !thread_db->all_symbols_looked_up)
- return;
- /* find_one_thread calls into libthread_db which accesses memory via
- the current thread. Temporarily switch to a thread we know is
- stopped. */
- scoped_restore_current_thread restore_thread;
- switch_to_thread (parent_thr);
- if (!find_one_thread (child_ptid))
- warning ("Cannot find thread after clone.");
- }
|