/* Thread management interface, for the remote server for GDB.
- Copyright (C) 2002, 2004, 2005, 2006, 2007, 2008, 2009, 2010
- Free Software Foundation, Inc.
+ Copyright (C) 2002-2015 Free Software Foundation, Inc.
Contributed by MontaVista Software.
static int thread_db_use_events;
#include "gdb_proc_service.h"
-#include "../gdb_thread_db.h"
+#include "nat/gdb_thread_db.h"
+#include "gdb_vecs.h"
#ifndef USE_LIBTHREAD_DB_DIRECTLY
#include <dlfcn.h>
/* 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
+ /* Thread creation event breakpoint. The code at this location in
+ the child process will be called by the pthread library whenever
+ a new thread is created. By setting a special breakpoint at this
+ location, GDB can detect when a new thread is created. We obtain
+ this location via the td_ta_event_addr call. Note that if the
+ running kernel supports tracing clones, then we don't need to use
+ (and in fact don't use) this magic thread event breakpoint to
+ learn about threads. */
+ struct breakpoint *td_create_bp;
+
/* Addresses of libthread_db functions. */
td_err_e (*td_ta_new_p) (struct ps_prochandle * ps, td_thragent_t **ta);
td_err_e (*td_ta_event_getmsg_p) (const td_thragent_t *ta,
td_err_e (*td_thr_tls_get_addr_p) (const td_thrhandle_t *th,
psaddr_t map_address,
size_t offset, psaddr_t *address);
+ td_err_e (*td_thr_tlsbase_p) (const td_thrhandle_t *th,
+ unsigned long int modid,
+ psaddr_t *base);
const char ** (*td_symbol_list_p) (void);
};
return "version mismatch between libthread_db and libpthread";
#endif
default:
- snprintf (buf, sizeof (buf), "unknown thread_db error '%d'", err);
+ xsnprintf (buf, sizeof (buf), "unknown thread_db error '%d'", err);
return buf;
}
}
case TD_THR_STOPPED_ASLEEP:
return "stopped by debugger AND blocked";
default:
- snprintf (buf, sizeof (buf), "unknown thread_db state %d", state);
+ xsnprintf (buf, sizeof (buf), "unknown thread_db state %d", state);
return buf;
}
}
struct lwp_info *lwp;
struct thread_db *thread_db = current_process ()->private->thread_db;
- if (thread_db->td_ta_event_getmsg_p == NULL)
- fatal ("unexpected thread_db->td_ta_event_getmsg_p == NULL");
+ gdb_assert (thread_db->td_ta_event_getmsg_p != NULL);
if (debug_threads)
- fprintf (stderr, "Thread creation event.\n");
+ debug_printf ("Thread creation event.\n");
/* FIXME: This assumes we don't get another event.
In the LinuxThreads implementation, this is safe,
/* If we do not know about the main thread yet, this would be a good time to
find it. We need to do this to pick up the main thread before any newly
created threads. */
- lwp = get_thread_lwp (current_inferior);
+ lwp = get_thread_lwp (current_thread);
if (lwp->thread_known == 0)
- find_one_thread (lwp->head.id);
+ find_one_thread (current_thread->entry.id);
/* msg.event == TD_EVENT_CREATE */
}
static int
-thread_db_enable_reporting ()
+thread_db_enable_reporting (void)
{
td_thr_events_t events;
td_notify_t notify;
thread_db_err_str (err));
return 0;
}
- set_breakpoint_at ((CORE_ADDR) (unsigned long) notify.u.bptaddr,
- thread_db_create_event);
+ thread_db->td_create_bp
+ = set_breakpoint_at ((CORE_ADDR) (unsigned long) notify.u.bptaddr,
+ thread_db_create_event);
return 1;
}
lwpid, thread_db_err_str (err));
if (debug_threads)
- fprintf (stderr, "Found thread %ld (LWP %d)\n",
- ti.ti_tid, ti.ti_lid);
+ debug_printf ("Found thread %ld (LWP %d)\n",
+ ti.ti_tid, ti.ti_lid);
if (lwpid != ti.ti_lid)
{
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_build (pid, ti_p->ti_lid, 0);
struct lwp_info *lwp;
+ int err;
if (debug_threads)
- fprintf (stderr, "Attaching to thread %ld (LWP %d)\n",
- ti_p->ti_tid, ti_p->ti_lid);
- linux_attach_lwp (ti_p->ti_lid);
- lwp = find_lwp_pid (pid_to_ptid (ti_p->ti_lid));
- if (lwp == NULL)
+ debug_printf ("Attaching to thread %ld (LWP %d)\n",
+ ti_p->ti_tid, ti_p->ti_lid);
+ err = linux_attach_lwp (ptid);
+ if (err != 0)
{
- warning ("Could not attach to thread %ld (LWP %d)\n",
- ti_p->ti_tid, ti_p->ti_lid);
+ warning ("Could not attach to thread %ld (LWP %d): %s\n",
+ ti_p->ti_tid, ti_p->ti_lid,
+ linux_ptrace_attach_fail_reason_string (ptid, err));
return 0;
}
+ lwp = find_lwp_pid (ptid);
+ gdb_assert (lwp != NULL);
lwp->thread_known = 1;
lwp->th = *th_p;
if (thread_db_use_events)
{
td_err_e err;
- struct thread_db *thread_db = current_process ()->private->thread_db;
+ struct thread_db *thread_db = proc->private->thread_db;
err = thread_db->td_thr_event_enable_p (th_p, 1);
if (err != TD_OK)
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. */
+ if (debug_threads)
+ debug_printf ("thread_db: skipping exited and "
+ "joined thread (0x%lx)\n", ti.ti_tid);
+ return 0;
+ }
+
/* Check for zombies. */
if (ti.ti_state == TD_THR_UNKNOWN || ti.ti_state == TD_THR_ZOMBIE)
return 0;
thread_db_find_new_threads (void)
{
td_err_e err;
- ptid_t ptid = ((struct inferior_list_entry *) current_inferior)->id;
+ ptid_t ptid = current_ptid;
struct thread_db *thread_db = current_process ()->private->thread_db;
int loop, iteration;
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_THR_ANY_STATE,
+ TD_THR_LOWEST_PRIORITY,
TD_SIGNO_MASK, TD_THR_ANY_USER_FLAGS);
if (debug_threads)
- fprintf (stderr, "Found %d threads in iteration %d.\n",
- new_thread_count, iteration);
+ debug_printf ("Found %d threads in iteration %d.\n",
+ new_thread_count, iteration);
if (new_thread_count != 0)
{
CORE_ADDR unused;
for (sym_list = thread_db->td_symbol_list_p (); *sym_list; sym_list++)
- look_up_one_symbol (*sym_list, &unused);
+ 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 ()->private->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
psaddr_t addr;
td_err_e err;
struct lwp_info *lwp;
- struct thread_info *saved_inferior;
+ struct thread_info *saved_thread;
struct process_info *proc;
struct thread_db *thread_db;
thread_db = proc->private->thread_db;
/* If the thread layer is not (yet) initialized, fail. */
- if (!proc->all_symbols_looked_up)
+ if (thread_db == NULL || !thread_db->all_symbols_looked_up)
return TD_ERR;
- if (thread_db->td_thr_tls_get_addr_p == NULL)
+ /* 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 (lwp->head.id);
+ find_one_thread (thread->entry.id);
if (!lwp->thread_known)
return TD_NOTHR;
- saved_inferior = current_inferior;
- current_inferior = thread;
- /* 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);
- current_inferior = saved_inferior;
+ saved_thread = current_thread;
+ current_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;
+ }
+
+ current_thread = saved_thread;
if (err == TD_OK)
{
*address = (CORE_ADDR) (uintptr_t) addr;
thread_db_load_search (void)
{
td_err_e err;
- struct thread_db tdb;
+ struct thread_db *tdb;
struct process_info *proc = current_process ();
- if (proc->private->thread_db != NULL)
- fatal ("unexpected: proc->private->thread_db != NULL");
+ gdb_assert (proc->private->thread_db == NULL);
+
+ tdb = xcalloc (1, sizeof (*tdb));
+ proc->private->thread_db = tdb;
- tdb.td_ta_new_p = &td_ta_new;
+ 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);
+ err = tdb->td_ta_new_p (&tdb->proc_handle, &tdb->thread_agent);
if (err != TD_OK)
{
if (debug_threads)
- fprintf (stderr, "td_ta_new(): %s\n", thread_db_err_str (err));
+ debug_printf ("td_ta_new(): %s\n", thread_db_err_str (err));
+ free (tdb);
+ proc->private->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;
+ 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;
/* This is required only when thread_db_use_events is on. */
- tdb.td_thr_event_enable_p = &td_thr_event_enable;
+ tdb->td_thr_event_enable_p = &td_thr_event_enable;
/* These are not essential. */
- tdb.td_ta_event_addr_p = &td_ta_event_addr;
- tdb.td_ta_set_event_p = &td_ta_set_event;
- tdb.td_ta_event_getmsg_p = &td_ta_event_getmsg;
- tdb.td_thr_tls_get_addr_p = &td_thr_tls_get_addr;
-
- proc->private->thread_db = xmalloc (sizeof (tdb));
- memcpy (proc->private->thread_db, &tdb, sizeof (tdb));
+ tdb->td_ta_event_addr_p = &td_ta_event_addr;
+ tdb->td_ta_set_event_p = &td_ta_set_event;
+ tdb->td_ta_event_getmsg_p = &td_ta_event_getmsg;
+ tdb->td_thr_tls_get_addr_p = &td_thr_tls_get_addr;
+ tdb->td_thr_tlsbase_p = &td_thr_tlsbase;
return 1;
}
try_thread_db_load_1 (void *handle)
{
td_err_e err;
- struct thread_db tdb;
+ struct thread_db *tdb;
struct process_info *proc = current_process ();
- if (proc->private->thread_db != NULL)
- fatal ("unexpected: proc->private->thread_db != NULL");
+ gdb_assert (proc->private->thread_db == NULL);
- tdb.handle = handle;
+ tdb = xcalloc (1, sizeof (*tdb));
+ proc->private->thread_db = tdb;
+
+ tdb->handle = handle;
/* Initialize pointers to the dynamic library functions we will use.
Essential functions first. */
if ((a) == NULL) \
{ \
if (debug_threads) \
- fprintf (stderr, "dlsym: %s\n", dlerror ()); \
+ debug_printf ("dlsym: %s\n", dlerror ()); \
if (required) \
- return 0; \
+ { \
+ free (tdb); \
+ proc->private->thread_db = NULL; \
+ return 0; \
+ } \
} \
} \
while (0)
- CHK (1, tdb.td_ta_new_p = dlsym (handle, "td_ta_new"));
+ CHK (1, tdb->td_ta_new_p = dlsym (handle, "td_ta_new"));
/* Attempt to open a connection to the thread library. */
- err = tdb.td_ta_new_p (&tdb.proc_handle, &tdb.thread_agent);
+ err = tdb->td_ta_new_p (&tdb->proc_handle, &tdb->thread_agent);
if (err != TD_OK)
{
if (debug_threads)
- fprintf (stderr, "td_ta_new(): %s\n", thread_db_err_str (err));
+ debug_printf ("td_ta_new(): %s\n", thread_db_err_str (err));
+ free (tdb);
+ proc->private->thread_db = NULL;
return 0;
}
- CHK (1, tdb.td_ta_map_lwp2thr_p = dlsym (handle, "td_ta_map_lwp2thr"));
- CHK (1, tdb.td_thr_get_info_p = dlsym (handle, "td_thr_get_info"));
- CHK (1, tdb.td_ta_thr_iter_p = dlsym (handle, "td_ta_thr_iter"));
- CHK (1, tdb.td_symbol_list_p = dlsym (handle, "td_symbol_list"));
+ CHK (1, tdb->td_ta_map_lwp2thr_p = dlsym (handle, "td_ta_map_lwp2thr"));
+ CHK (1, tdb->td_thr_get_info_p = dlsym (handle, "td_thr_get_info"));
+ CHK (1, tdb->td_ta_thr_iter_p = dlsym (handle, "td_ta_thr_iter"));
+ CHK (1, tdb->td_symbol_list_p = dlsym (handle, "td_symbol_list"));
/* This is required only when thread_db_use_events is on. */
CHK (thread_db_use_events,
- tdb.td_thr_event_enable_p = dlsym (handle, "td_thr_event_enable"));
+ tdb->td_thr_event_enable_p = dlsym (handle, "td_thr_event_enable"));
/* These are not essential. */
- CHK (0, tdb.td_ta_event_addr_p = dlsym (handle, "td_ta_event_addr"));
- CHK (0, tdb.td_ta_set_event_p = dlsym (handle, "td_ta_set_event"));
- CHK (0, tdb.td_ta_event_getmsg_p = dlsym (handle, "td_ta_event_getmsg"));
- CHK (0, tdb.td_thr_tls_get_addr_p = dlsym (handle, "td_thr_tls_get_addr"));
+ CHK (0, tdb->td_ta_event_addr_p = dlsym (handle, "td_ta_event_addr"));
+ CHK (0, tdb->td_ta_set_event_p = dlsym (handle, "td_ta_set_event"));
+ CHK (0, tdb->td_ta_event_getmsg_p = dlsym (handle, "td_ta_event_getmsg"));
+ CHK (0, tdb->td_thr_tls_get_addr_p = dlsym (handle, "td_thr_tls_get_addr"));
+ CHK (0, tdb->td_thr_tlsbase_p = dlsym (handle, "td_thr_tlsbase"));
#undef CHK
- proc->private->thread_db = xmalloc (sizeof (tdb));
- memcpy (proc->private->thread_db, &tdb, sizeof (tdb));
-
return 1;
}
void *handle;
if (debug_threads)
- fprintf (stderr, "Trying host libthread_db library: %s.\n",
- library);
+ debug_printf ("Trying host libthread_db library: %s.\n",
+ library);
handle = dlopen (library, RTLD_NOW);
if (handle == NULL)
{
if (debug_threads)
- fprintf (stderr, "dlopen failed: %s.\n", dlerror ());
+ debug_printf ("dlopen failed: %s.\n", dlerror ());
return 0;
}
return 0;
}
+/* Handle $sdir in libthread-db-search-path.
+ Look for libthread_db in the system dirs, or wherever a plain
+ dlopen(file_without_path) will look.
+ The result is true for success. */
+
static int
-thread_db_load_search (void)
+try_thread_db_load_from_sdir (void)
+{
+ return try_thread_db_load (LIBTHREAD_DB_SO);
+}
+
+/* Try to load libthread_db from directory DIR of length DIR_LEN.
+ The result is true for success. */
+
+static int
+try_thread_db_load_from_dir (const char *dir, size_t dir_len)
{
char path[PATH_MAX];
- const char *search_path;
- int rc = 0;
+
+ if (dir_len + 1 + strlen (LIBTHREAD_DB_SO) + 1 > sizeof (path))
+ {
+ char *cp = xmalloc (dir_len + 1);
+
+ memcpy (cp, dir, dir_len);
+ cp[dir_len] = '\0';
+ warning (_("libthread-db-search-path component too long,"
+ " ignored: %s."), cp);
+ free (cp);
+ return 0;
+ }
+
+ memcpy (path, dir, dir_len);
+ path[dir_len] = '/';
+ strcpy (path + dir_len + 1, LIBTHREAD_DB_SO);
+ return try_thread_db_load (path);
+}
+
+/* Search libthread_db_search_path for libthread_db which "agrees"
+ to work on current inferior.
+ The result is true for success. */
+
+static int
+thread_db_load_search (void)
+{
+ VEC (char_ptr) *dir_vec;
+ char *this_dir;
+ int i, rc = 0;
if (libthread_db_search_path == NULL)
libthread_db_search_path = xstrdup (LIBTHREAD_DB_SEARCH_PATH);
- search_path = libthread_db_search_path;
- while (*search_path)
+ dir_vec = dirnames_to_char_ptr_vec (libthread_db_search_path);
+
+ for (i = 0; VEC_iterate (char_ptr, dir_vec, i, this_dir); ++i)
{
- const char *end = strchr (search_path, ':');
- if (end)
+ const int pdir_len = sizeof ("$pdir") - 1;
+ size_t this_dir_len;
+
+ this_dir_len = strlen (this_dir);
+
+ if (strncmp (this_dir, "$pdir", pdir_len) == 0
+ && (this_dir[pdir_len] == '\0'
+ || this_dir[pdir_len] == '/'))
{
- size_t len = end - search_path;
- if (len + 1 + strlen (LIBTHREAD_DB_SO) + 1 > sizeof (path))
+ /* We don't maintain a list of loaded libraries so we don't know
+ where libpthread lives. We *could* fetch the info, but we don't
+ do that yet. Ignore it. */
+ }
+ else if (strcmp (this_dir, "$sdir") == 0)
+ {
+ if (try_thread_db_load_from_sdir ())
{
- char *cp = xmalloc (len + 1);
- memcpy (cp, search_path, len);
- cp[len] = '\0';
- warning ("libthread_db_search_path component too long, "
- "ignored: %s.", cp);
- free (cp);
- search_path += len + 1;
- continue;
+ rc = 1;
+ break;
}
- memcpy (path, search_path, len);
- path[len] = '\0';
- search_path += len + 1;
}
else
{
- size_t len = strlen (search_path);
-
- if (len + 1 + strlen (LIBTHREAD_DB_SO) + 1 > sizeof (path))
+ if (try_thread_db_load_from_dir (this_dir, this_dir_len))
{
- warning ("libthread_db_search_path component too long,"
- " ignored: %s.", search_path);
+ rc = 1;
break;
}
- memcpy (path, search_path, len + 1);
- search_path += len;
- }
- strcat (path, "/");
- strcat (path, LIBTHREAD_DB_SO);
- if (debug_threads)
- fprintf (stderr, "thread_db_load_search trying %s\n", path);
- if (try_thread_db_load (path))
- {
- rc = 1;
- break;
}
}
- if (rc == 0)
- rc = try_thread_db_load (LIBTHREAD_DB_SO);
+ free_char_ptr_vec (dir_vec);
if (debug_threads)
- fprintf (stderr, "thread_db_load_search returning %d\n", rc);
+ debug_printf ("thread_db_load_search returning %d\n", rc);
return rc;
}
}
thread_db_find_new_threads ();
thread_db_look_up_symbols ();
- proc->all_symbols_looked_up = 1;
return 1;
}
return 0;
}
+static void
+switch_to_process (struct process_info *proc)
+{
+ int pid = pid_of (proc);
+
+ current_thread =
+ (struct thread_info *) find_inferior (&all_threads,
+ any_thread_of, &pid);
+}
+
/* Disconnect from libthread_db and free resources. */
static void
if (td_ta_clear_event_p != NULL)
{
- struct thread_info *saved_inferior;
+ struct thread_info *saved_thread = current_thread;
td_thr_events_t events;
- int pid;
- pid = pid_of (proc);
- saved_inferior = current_inferior;
- current_inferior =
- (struct thread_info *) find_inferior (&all_threads,
- any_thread_of, &pid);
+ 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);
- current_inferior = saved_inferior;
+ current_thread = saved_thread;
}
}
}
+static void
+remove_thread_event_breakpoints (struct process_info *proc)
+{
+ struct thread_db *thread_db = proc->private->thread_db;
+
+ if (thread_db->td_create_bp != NULL)
+ {
+ struct thread_info *saved_thread = current_thread;
+
+ switch_to_process (proc);
+
+ delete_breakpoint (thread_db->td_create_bp);
+ thread_db->td_create_bp = NULL;
+
+ current_thread = saved_thread;
+ }
+}
+
void
thread_db_detach (struct process_info *proc)
{
- disable_thread_event_reporting (proc);
+ struct thread_db *thread_db = proc->private->thread_db;
+
+ if (thread_db)
+ {
+ disable_thread_event_reporting (proc);
+ remove_thread_event_breakpoints (proc);
+ }
}
/* Disconnect from libthread_db and free resources. */
int
thread_db_handle_monitor_command (char *mon)
{
- if (strncmp (mon, "set libthread-db-search-path ", 29) == 0)
+ 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 + 29;
+ const char *cp = mon + cmd_len;
if (libthread_db_search_path != NULL)
free (libthread_db_search_path);
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 `");