/* libthread_db assisted debugging support, generic parts.
- Copyright (C) 1999, 2000, 2001, 2003, 2004, 2005, 2006, 2007, 2008, 2009,
- 2010, 2011 Free Software Foundation, Inc.
+ Copyright (C) 1999-2001, 2003-2012 Free Software Foundation, Inc.
This file is part of GDB.
#include "gdbcore.h"
#include "observer.h"
#include "linux-nat.h"
+#include "linux-procfs.h"
#include <signal.h>
static char *libthread_db_search_path;
+static void
+set_libthread_db_search_path (char *ignored, int from_tty,
+ struct cmd_list_element *c)
+{
+ if (*libthread_db_search_path == '\0')
+ {
+ xfree (libthread_db_search_path);
+ libthread_db_search_path = xstrdup (LIBTHREAD_DB_SEARCH_PATH);
+ }
+}
+
/* If non-zero, print details of libthread_db processing. */
static int libthread_db_debug;
fprintf_filtered (file, _("libthread-db debugging is %s.\n"), value);
}
-
/* If we're running on GNU/Linux, we must explicitly attach to any new
threads. */
struct thread_db_info *info;
struct thread_get_info_inout io = {0};
+ /* Just in case td_ta_map_lwp2thr doesn't initialize it completely. */
+ th.th_unique = 0;
+
/* This ptid comes from linux-nat.c, which should always fill in the
LWP. */
gdb_assert (GET_LWP (ptid) != 0);
return NULL;
}
-/* Attempt to initialize dlopen()ed libthread_db, described by HANDLE.
+/* Attempt to initialize dlopen()ed libthread_db, described by INFO.
Return 1 on success.
Failure could happen if libthread_db does not have symbols we expect,
or when it refuses to work with the current inferior (e.g. due to
return 0;
}
+/* Subroutine of try_thread_db_load_from_pdir to simplify it.
+ Try loading libthread_db from the same directory as OBJ.
+ The result is true for success. */
+
+static int
+try_thread_db_load_from_pdir_1 (struct objfile *obj)
+{
+ struct cleanup *cleanup;
+ char *path, *cp;
+ int result;
+
+ if (obj->name[0] != '/')
+ {
+ warning (_("Expected absolute pathname for libpthread in the"
+ " inferior, but got %s."), obj->name);
+ return 0;
+ }
+
+ path = xmalloc (strlen (obj->name) + 1 + strlen (LIBTHREAD_DB_SO) + 1);
+ cleanup = make_cleanup (xfree, path);
+
+ strcpy (path, obj->name);
+ cp = strrchr (path, '/');
+ /* This should at minimum hit the first character. */
+ gdb_assert (cp != NULL);
+ strcpy (cp + 1, LIBTHREAD_DB_SO);
+ result = try_thread_db_load (path);
+
+ do_cleanups (cleanup);
+ return result;
+}
+
+/* Handle $pdir in libthread-db-search-path.
+ Look for libthread_db in the directory of libpthread.
+ The result is true for success. */
+
+static int
+try_thread_db_load_from_pdir (void)
+{
+ struct objfile *obj;
+
+ ALL_OBJFILES (obj)
+ if (libpthread_name_p (obj->name))
+ {
+ if (try_thread_db_load_from_pdir_1 (obj))
+ return 1;
+
+ /* We may have found the separate-debug-info version of
+ libpthread, and it may live in a directory without a matching
+ libthread_db. */
+ if (obj->separate_debug_objfile_backlink != NULL)
+ return try_thread_db_load_from_pdir_1 (obj->separate_debug_objfile_backlink);
+
+ 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
+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)
+{
+ struct cleanup *cleanup;
+ char *path;
+ int result;
+
+ path = xmalloc (dir_len + 1 + strlen (LIBTHREAD_DB_SO) + 1);
+ cleanup = make_cleanup (xfree, path);
+
+ memcpy (path, dir, dir_len);
+ path[dir_len] = '/';
+ strcpy (path + dir_len + 1, LIBTHREAD_DB_SO);
+ result = try_thread_db_load (path);
+
+ do_cleanups (cleanup);
+ return result;
+}
/* Search libthread_db_search_path for libthread_db which "agrees"
- to work on current inferior. */
+ to work on current inferior.
+ The result is true for success. */
static int
thread_db_load_search (void)
{
- char path[PATH_MAX];
const char *search_path = libthread_db_search_path;
int rc = 0;
while (*search_path)
{
const char *end = strchr (search_path, ':');
+ const char *this_dir = search_path;
+ size_t this_dir_len;
if (end)
{
- size_t len = end - search_path;
-
- if (len + 1 + strlen (LIBTHREAD_DB_SO) + 1 > sizeof (path))
- {
- char *cp = xmalloc (len + 1);
-
- memcpy (cp, search_path, len);
- cp[len] = '\0';
- warning (_("libthread_db_search_path component too long,"
- " ignored: %s."), cp);
- xfree (cp);
- search_path += len + 1;
- continue;
- }
- memcpy (path, search_path, len);
- path[len] = '\0';
- search_path += len + 1;
+ this_dir_len = end - search_path;
+ search_path += this_dir_len + 1;
}
else
{
- size_t len = strlen (search_path);
+ this_dir_len = strlen (this_dir);
+ search_path += this_dir_len;
+ }
- if (len + 1 + strlen (LIBTHREAD_DB_SO) + 1 > sizeof (path))
- {
- warning (_("libthread_db_search_path component too long,"
- " ignored: %s."), search_path);
- break;
- }
- memcpy (path, search_path, len + 1);
- search_path += len;
+ if (this_dir_len == sizeof ("$pdir") - 1
+ && strncmp (this_dir, "$pdir", this_dir_len) == 0)
+ {
+ if (try_thread_db_load_from_pdir ())
+ {
+ rc = 1;
+ break;
+ }
}
- strcat (path, "/");
- strcat (path, LIBTHREAD_DB_SO);
- if (try_thread_db_load (path))
+ else if (this_dir_len == sizeof ("$sdir") - 1
+ && strncmp (this_dir, "$sdir", this_dir_len) == 0)
{
- rc = 1;
- break;
+ 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;
+ }
}
}
- if (rc == 0)
- rc = try_thread_db_load (LIBTHREAD_DB_SO);
+
+ if (libthread_db_debug)
+ printf_unfiltered (_("thread_db_load_search returning %d\n"), rc);
return rc;
}
+/* Return non-zero if the inferior has a libpthread. */
+
+static int
+has_libpthread (void)
+{
+ struct objfile *obj;
+
+ ALL_OBJFILES (obj)
+ if (libpthread_name_p (obj->name))
+ return 1;
+
+ return 0;
+}
+
/* Attempt to load and initialize libthread_db.
- Return 1 on success.
- */
+ Return 1 on success. */
static int
thread_db_load (void)
{
- struct objfile *obj;
struct thread_db_info *info;
info = get_thread_db_info (GET_PID (inferior_ptid));
if (thread_db_load_search ())
return 1;
- /* None of the libthread_db's on our search path, not the system default
- ones worked. If the executable is dynamically linked against
- libpthread, try loading libthread_db from the same directory. */
-
- ALL_OBJFILES (obj)
- if (libpthread_name_p (obj->name))
- {
- char path[PATH_MAX], *cp;
-
- gdb_assert (strlen (obj->name) < sizeof (path));
- strcpy (path, obj->name);
- cp = strrchr (path, '/');
-
- if (cp == NULL)
- {
- warning (_("Expected absolute pathname for libpthread in the"
- " inferior, but got %s."), path);
- }
- else if (cp + 1 + strlen (LIBTHREAD_DB_SO) + 1 > path + sizeof (path))
- {
- warning (_("Unexpected: path to libpthread in the inferior is"
- " too long: %s"), path);
- }
- else
- {
- strcpy (cp + 1, LIBTHREAD_DB_SO);
- if (try_thread_db_load (path))
- return 1;
- }
- warning (_("Unable to find libthread_db matching inferior's thread"
- " library, thread debugging will not be available."));
- return 0;
+ /* We couldn't find a libthread_db.
+ If the inferior has a libpthread warn the user. */
+ if (has_libpthread ())
+ {
+ warning (_("Unable to find libthread_db matching inferior's thread"
+ " library, thread debugging will not be available."));
+ return 0;
}
+
/* Either this executable isn't using libpthread at all, or it is
statically linked. Since we can't easily distinguish these two cases,
no warning is issued. */
return;
}
+/* This function is called via the new_objfile observer. */
+
static void
thread_db_new_objfile (struct objfile *objfile)
{
/* This observer must always be called with inferior_ptid set
correctly. */
- if (objfile != NULL)
+ if (objfile != NULL
+ /* Only check for thread_db if we loaded libpthread,
+ or if this is the main symbol file.
+ We need to check OBJF_MAINLINE to handle the case of debugging
+ a statically linked executable AND the symbol file is specified AFTER
+ the exec file is loaded (e.g., gdb -c core ; file foo).
+ For dynamically linked executables, libpthread can be near the end
+ of the list of shared libraries to load, and in an app of several
+ thousand shared libraries, this can otherwise be painful. */
+ && ((objfile->flags & OBJF_MAINLINE) != 0
+ || libpthread_name_p (objfile->name)))
check_for_thread_db ();
}
+/* This function is called via the inferior_created observer.
+ This handles the case of debugging statically linked executables. */
+
+static void
+thread_db_inferior_created (struct target_ops *target, int from_tty)
+{
+ check_for_thread_db ();
+}
+
/* Attach to a new thread. This function is called when we receive a
TD_CREATE event or when we iterate over all threads and find one
that wasn't already in our list. Returns true on success. */
/* Under GNU/Linux, we have to attach to each and every thread. */
if (target_has_execution
- && tp == NULL
- && lin_lwp_attach_lwp (BUILD_LWP (ti_p->ti_lid, GET_PID (ptid))) < 0)
- return 0;
+ && tp == NULL)
+ {
+ int res;
+
+ res = lin_lwp_attach_lwp (BUILD_LWP (ti_p->ti_lid, GET_PID (ptid)));
+ if (res < 0)
+ {
+ /* Error, stop iterating. */
+ return 0;
+ }
+ else if (res > 0)
+ {
+ /* Pretend this thread doesn't exist yet, and keep
+ iterating. */
+ return 1;
+ }
+
+ /* Otherwise, we sucessfully attached to the thread. */
+ }
/* Construct the thread's private data. */
private = xmalloc (sizeof (struct private_thread_info));
/* Add the thread to GDB's thread list. */
if (tp == NULL)
- tp = add_thread_with_info (ptid, private);
+ add_thread_with_info (ptid, private);
else
tp->private = private;
if (ti.ti_state == TD_THR_UNKNOWN || ti.ti_state == TD_THR_ZOMBIE)
return 0; /* A zombie -- ignore. */
- if (ti.ti_tid == 0 && target_has_execution)
+ if (ti.ti_tid == 0)
{
/* A thread ID of zero means that this is the main thread, but
glibc has not yet initialized thread-local storage and the
need this glibc bug workaround. */
info->need_stale_parent_threads_check = 0;
- err = info->td_thr_event_enable_p (th_p, 1);
- if (err != TD_OK)
- error (_("Cannot enable thread event reporting for LWP %d: %s"),
- (int) ti.ti_lid, thread_db_err_str (err));
+ if (target_has_execution)
+ {
+ err = info->td_thr_event_enable_p (th_p, 1);
+ if (err != TD_OK)
+ error (_("Cannot enable thread event reporting for LWP %d: %s"),
+ (int) ti.ti_lid, thread_db_err_str (err));
+ }
return 0;
}
int pid = ptid_get_pid (ptid);
int i, loop;
- if (target_has_execution)
- {
- struct lwp_info *lp;
-
- /* In linux, we can only read memory through a stopped lwp. */
- ALL_LWPS (lp, ptid)
- if (lp->stopped && ptid_get_pid (lp->ptid) == pid)
- break;
-
- if (!lp)
- /* There is no stopped thread. Bail out. */
- return;
- }
-
info = get_thread_db_info (GET_PID (ptid));
/* Access an lwp we know is stopped. */
thread_db_find_new_threads (struct target_ops *ops)
{
struct thread_db_info *info;
+ struct inferior *inf;
- info = get_thread_db_info (GET_PID (inferior_ptid));
+ ALL_INFERIORS (inf)
+ {
+ struct thread_info *thread;
- if (info == NULL)
- return;
+ if (inf->pid == 0)
+ continue;
- thread_db_find_new_threads_1 (inferior_ptid);
+ info = get_thread_db_info (inf->pid);
+ if (info == NULL)
+ continue;
+
+ thread = any_live_thread_of_process (inf->pid);
+ if (thread == NULL || thread->executing)
+ continue;
+
+ thread_db_find_new_threads_1 (thread->ptid);
+ }
if (target_has_execution)
iterate_over_lwps (minus_one_ptid /* iterate over all */,
executable -- there could be mutiple versions of glibc,
compiled with LinuxThreads or NPTL, and until there is
a running inferior, we can't tell which libthread_db is
- the correct one to load. */
+ the correct one to load. */
libthread_db_search_path = xstrdup (LIBTHREAD_DB_SEARCH_PATH);
Set search path for libthread_db."), _("\
Show the current search path or libthread_db."), _("\
This path is used to search for libthread_db to be loaded into \
-gdb itself."),
- NULL,
+gdb itself.\n\
+Its value is a colon (':') separate list of directories to search.\n\
+Setting the search path to an empty list resets it to its default value."),
+ set_libthread_db_search_path,
NULL,
&setlist, &showlist);
/* Add ourselves to objfile event chain. */
observer_attach_new_objfile (thread_db_new_objfile);
+
+ /* Add ourselves to inferior_created event chain.
+ This is needed to handle debugging statically linked programs where
+ the new_objfile observer won't get called for libpthread. */
+ observer_attach_inferior_created (thread_db_inferior_created);
}
projects / deliverable / binutils-gdb.git / blobdiff