e02bc4cc30
* arch-utils.c (default_prepare_to_proceed) (generic_prepare_to_proceed): Added new functions. * arch-utils.h: New function declarations for default_prepare_to_proceed() and generic_prepare_to_proceed(). * gdbarch.sh: Added PREPARE_TO_PROCEED. * gdbarch.c: Regenerated. * gdbarch.h: Regenerated. * inferior.h: Added get_last_target_status() declaration. * infrun.c (get_last_target_status): Added new function. (handle_inferior_event): Saves last pid and waitstatus, which will get returned by get_last_target_status(). * hppa-tdep.c (prepare_to_proceed): Added comment stating that prepare_to_proceed() is potentially redundant since default_prepare_to_proceed() has been added. * linux-thread.c (prepare_to_proceed): Ditto. * lin-lwp.c (prepare_to_proceed): Ditto. * m3-nat.c (prepare_to_proceed): Ditto.
1762 lines
49 KiB
C
1762 lines
49 KiB
C
/* Low level interface for debugging GNU/Linux threads for GDB,
|
||
the GNU debugger.
|
||
Copyright 1998, 1999, 2000 Free Software Foundation, Inc.
|
||
|
||
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 2 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, write to the Free Software
|
||
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
|
||
|
||
/* This module implements the debugging interface of the linuxthreads package
|
||
of the glibc. This package implements a simple clone()-based implementation
|
||
of Posix threads for Linux. To use this module, be sure that you have at
|
||
least the version of the linuxthreads package that holds the support of
|
||
GDB (currently 0.8 included in the glibc-2.0.7).
|
||
|
||
Right now, the linuxthreads package does not care of priority scheduling,
|
||
so, neither this module does; In particular, the threads are resumed
|
||
in any order, which could lead to different scheduling than the one
|
||
happening when GDB does not control the execution.
|
||
|
||
The latest point is that ptrace(PT_ATTACH, ...) is intrusive in Linux:
|
||
When a process is attached, then the attaching process becomes the current
|
||
parent of the attached process, and the old parent has lost this child.
|
||
If the old parent does a wait[...](), then this child is no longer
|
||
considered by the kernel as a child of the old parent, thus leading to
|
||
results of the call different when the child is attached and when it's not.
|
||
|
||
A fix has been submitted to the Linux community to solve this problem,
|
||
which consequences are not visible to the application itself, but on the
|
||
process which may wait() for the completion of the application (mostly,
|
||
it may consider that the application no longer exists (errno == ECHILD),
|
||
although it does, and thus being unable to get the exit status and resource
|
||
usage of the child. If by chance, it is able to wait() for the application
|
||
after it has died (by receiving first a SIGCHILD, and then doing a wait(),
|
||
then the exit status and resource usage may be wrong, because the
|
||
linuxthreads package heavily relies on wait() synchronization to keep
|
||
them correct. */
|
||
|
||
#include "defs.h"
|
||
#include <sys/types.h> /* for pid_t */
|
||
#include <sys/ptrace.h> /* for PT_* flags */
|
||
#include "gdb_wait.h" /* for WUNTRACED and __WCLONE flags */
|
||
#include <signal.h> /* for struct sigaction and NSIG */
|
||
#include <sys/utsname.h>
|
||
|
||
#include "target.h"
|
||
#include "inferior.h"
|
||
#include "gdbcore.h"
|
||
#include "gdbthread.h"
|
||
#include "gdbcmd.h"
|
||
#include "breakpoint.h"
|
||
|
||
#ifndef PT_ATTACH
|
||
#define PT_ATTACH PTRACE_ATTACH
|
||
#endif
|
||
#ifndef PT_KILL
|
||
#define PT_KILL PTRACE_KILL
|
||
#endif
|
||
#ifndef PT_READ_U
|
||
#define PT_READ_U PTRACE_PEEKUSR
|
||
#endif
|
||
|
||
#ifdef NSIG
|
||
#define LINUXTHREAD_NSIG NSIG
|
||
#else
|
||
#ifdef _NSIG
|
||
#define LINUXTHREAD_NSIG _NSIG
|
||
#endif
|
||
#endif
|
||
|
||
extern int child_suppress_run; /* make inftarg.c non-runnable */
|
||
struct target_ops linuxthreads_ops; /* Forward declaration */
|
||
extern struct target_ops child_ops; /* target vector for inftarg.c */
|
||
|
||
static CORE_ADDR linuxthreads_handles; /* array of linuxthreads handles */
|
||
static CORE_ADDR linuxthreads_manager; /* pid of linuxthreads manager thread */
|
||
static CORE_ADDR linuxthreads_initial; /* pid of linuxthreads initial thread */
|
||
static CORE_ADDR linuxthreads_debug; /* linuxthreads internal debug flag */
|
||
static CORE_ADDR linuxthreads_num; /* number of valid handle entries */
|
||
|
||
static int linuxthreads_max; /* Maximum number of linuxthreads.
|
||
Zero if this executable doesn't use
|
||
threads, or wasn't linked with a
|
||
debugger-friendly version of the
|
||
linuxthreads library. */
|
||
|
||
static int linuxthreads_sizeof_handle; /* size of a linuxthreads handle */
|
||
static int linuxthreads_offset_descr; /* h_descr offset of the linuxthreads
|
||
handle */
|
||
static int linuxthreads_offset_pid; /* p_pid offset of the linuxthreads
|
||
descr */
|
||
|
||
static int linuxthreads_manager_pid; /* manager pid */
|
||
static int linuxthreads_initial_pid; /* initial pid */
|
||
|
||
/* These variables form a bag of threads with interesting status. If
|
||
wait_thread (PID) finds that PID stopped for some interesting
|
||
reason (i.e. anything other than stopped with SIGSTOP), then it
|
||
records its status in this queue. linuxthreads_wait and
|
||
linuxthreads_find_trap extract processes from here. */
|
||
static int *linuxthreads_wait_pid; /* wait array of pid */
|
||
static int *linuxthreads_wait_status; /* wait array of status */
|
||
static int linuxthreads_wait_last; /* index of last valid elt in
|
||
linuxthreads_wait_{pid,status} */
|
||
|
||
static sigset_t linuxthreads_block_mask; /* sigset without SIGCHLD */
|
||
|
||
static int linuxthreads_step_pid; /* current stepped pid */
|
||
static int linuxthreads_step_signo; /* current stepped target signal */
|
||
static int linuxthreads_exit_status; /* exit status of initial thread */
|
||
|
||
static int linuxthreads_inferior_pid; /* temporary internal inferior pid */
|
||
static int linuxthreads_breakpoint_pid; /* last pid that hit a breakpoint */
|
||
static int linuxthreads_attach_pending; /* attach command without wait */
|
||
|
||
static int linuxthreads_breakpoints_inserted; /* any breakpoints inserted */
|
||
|
||
/* LinuxThreads uses certain signals for communication between
|
||
processes; we need to tell GDB to pass them through silently to the
|
||
inferior. The LinuxThreads library has global variables we can
|
||
read containing the relevant signal numbers, but since the signal
|
||
numbers are chosen at run-time, those variables aren't initialized
|
||
until the shared library's constructors have had a chance to run. */
|
||
|
||
struct linuxthreads_signal {
|
||
|
||
/* The name of the LinuxThreads library variable that contains
|
||
the signal number. */
|
||
char *var;
|
||
|
||
/* True if this variable must exist for us to debug properly. */
|
||
int required;
|
||
|
||
/* The variable's address in the inferior, or zero if the
|
||
LinuxThreads library hasn't been loaded into this inferior yet. */
|
||
CORE_ADDR addr;
|
||
|
||
/* The signal number, or zero if we don't know yet (either because
|
||
we haven't found the variable, or it hasn't been initialized).
|
||
This is an actual target signal number that you could pass to
|
||
`kill', not a GDB signal number. */
|
||
int signal;
|
||
|
||
/* GDB's original settings for `stop' and `print' for this signal.
|
||
We restore them when the user selects a different executable.
|
||
Invariant: if sig->signal != 0, then sig->{stop,print} contain
|
||
the original settings. */
|
||
int stop, print;
|
||
};
|
||
|
||
struct linuxthreads_signal linuxthreads_sig_restart = {
|
||
"__pthread_sig_restart", 1, 0, 0, 0, 0
|
||
};
|
||
struct linuxthreads_signal linuxthreads_sig_cancel = {
|
||
"__pthread_sig_cancel", 1, 0, 0, 0, 0
|
||
};
|
||
struct linuxthreads_signal linuxthreads_sig_debug = {
|
||
"__pthread_sig_debug", 0, 0, 0, 0, 0
|
||
};
|
||
|
||
/* Set by thread_db module when it takes over the thread_stratum.
|
||
In that case we must:
|
||
a) refrain from turning on the debug signal, and
|
||
b) refrain from calling add_thread. */
|
||
|
||
int using_thread_db = 0;
|
||
|
||
/* A table of breakpoint locations, one per PID. */
|
||
static struct linuxthreads_breakpoint {
|
||
CORE_ADDR pc; /* PC of breakpoint */
|
||
int pid; /* pid of breakpoint */
|
||
int step; /* whether the pc has been reached after sstep */
|
||
} *linuxthreads_breakpoint_zombie; /* Zombie breakpoints array */
|
||
static int linuxthreads_breakpoint_last; /* Last zombie breakpoint */
|
||
|
||
/* linuxthreads_{insert,remove}_breakpoint pass the breakpoint address
|
||
to {insert,remove}_breakpoint via this variable, since
|
||
iterate_active_threads doesn't provide any way to pass values
|
||
through to the worker function. */
|
||
static CORE_ADDR linuxthreads_breakpoint_addr;
|
||
|
||
#define REMOVE_BREAKPOINT_ZOMBIE(_i) \
|
||
{ \
|
||
if ((_i) < linuxthreads_breakpoint_last) \
|
||
linuxthreads_breakpoint_zombie[(_i)] = \
|
||
linuxthreads_breakpoint_zombie[linuxthreads_breakpoint_last]; \
|
||
linuxthreads_breakpoint_last--; \
|
||
}
|
||
|
||
|
||
|
||
#ifndef PTRACE_XFER_TYPE
|
||
#define PTRACE_XFER_TYPE int
|
||
#endif
|
||
/* Check to see if the given thread is alive. */
|
||
static int
|
||
linuxthreads_thread_alive (int pid)
|
||
{
|
||
errno = 0;
|
||
return ptrace (PT_READ_U, pid, (PTRACE_ARG3_TYPE)0, 0) >= 0 || errno == 0;
|
||
}
|
||
|
||
/* On detach(), find a SIGTRAP status. If stop is non-zero, find a
|
||
SIGSTOP one, too.
|
||
|
||
Make sure PID is ready to run, and free of interference from our
|
||
efforts to debug it (e.g., pending SIGSTOP or SIGTRAP signals). If
|
||
STOP is zero, just look for a SIGTRAP. If STOP is non-zero, look
|
||
for a SIGSTOP, too. Return non-zero if PID is alive and ready to
|
||
run; return zero if PID is dead.
|
||
|
||
PID may or may not be stopped at the moment, and we may or may not
|
||
have waited for it already. We check the linuxthreads_wait bag in
|
||
case we've already got a status for it. We may possibly wait for
|
||
it ourselves.
|
||
|
||
PID may have signals waiting to be delivered. If they're caused by
|
||
our efforts to debug it, accept them with wait, but don't pass them
|
||
through to PID. Do pass all other signals through. */
|
||
static int
|
||
linuxthreads_find_trap (int pid, int stop)
|
||
{
|
||
int i;
|
||
int rpid;
|
||
int status;
|
||
int found_stop = 0;
|
||
int found_trap = 0;
|
||
|
||
/* PID may have any number of signals pending. The kernel will
|
||
report each of them to us via wait, and then it's up to us to
|
||
pass them along to the process via ptrace, if we so choose.
|
||
|
||
We need to paw through the whole set until we've found a SIGTRAP
|
||
(or a SIGSTOP, if `stop' is set). We don't pass the SIGTRAP (or
|
||
SIGSTOP) through, but we do re-send all the others, so PID will
|
||
receive them when we resume it. */
|
||
int *wstatus = alloca (LINUXTHREAD_NSIG * sizeof (int));
|
||
int last = 0;
|
||
|
||
/* Look at the pending status */
|
||
for (i = linuxthreads_wait_last; i >= 0; i--)
|
||
if (linuxthreads_wait_pid[i] == pid)
|
||
{
|
||
status = linuxthreads_wait_status[i];
|
||
|
||
/* Delete the i'th member of the table. Since the table is
|
||
unordered, we can do this simply by copying the table's
|
||
last element to the i'th position, and shrinking the table
|
||
by one element. */
|
||
if (i < linuxthreads_wait_last)
|
||
{
|
||
linuxthreads_wait_status[i] =
|
||
linuxthreads_wait_status[linuxthreads_wait_last];
|
||
linuxthreads_wait_pid[i] =
|
||
linuxthreads_wait_pid[linuxthreads_wait_last];
|
||
}
|
||
linuxthreads_wait_last--;
|
||
|
||
if (!WIFSTOPPED(status)) /* Thread has died */
|
||
return 0;
|
||
|
||
if (WSTOPSIG(status) == SIGTRAP)
|
||
{
|
||
if (stop)
|
||
found_trap = 1;
|
||
else
|
||
return 1;
|
||
}
|
||
else if (WSTOPSIG(status) == SIGSTOP)
|
||
{
|
||
if (stop)
|
||
found_stop = 1;
|
||
}
|
||
else
|
||
{
|
||
wstatus[0] = status;
|
||
last = 1;
|
||
}
|
||
|
||
break;
|
||
}
|
||
|
||
if (stop)
|
||
{
|
||
/* Make sure that we'll find what we're looking for. */
|
||
if (!found_trap)
|
||
{
|
||
kill (pid, SIGTRAP);
|
||
}
|
||
if (!found_stop)
|
||
{
|
||
kill (pid, SIGSTOP);
|
||
}
|
||
}
|
||
|
||
/* Catch all status until SIGTRAP and optionally SIGSTOP show up. */
|
||
for (;;)
|
||
{
|
||
/* resume the child every time... */
|
||
child_resume (pid, 1, TARGET_SIGNAL_0);
|
||
|
||
/* loop as long as errno == EINTR:
|
||
waitpid syscall may be aborted due to GDB receiving a signal.
|
||
FIXME: EINTR handling should no longer be necessary here, since
|
||
we now block SIGCHLD except in an explicit sigsuspend call. */
|
||
|
||
for (;;)
|
||
{
|
||
rpid = waitpid (pid, &status, __WCLONE);
|
||
if (rpid > 0)
|
||
{
|
||
break;
|
||
}
|
||
if (errno == EINTR)
|
||
{
|
||
continue;
|
||
}
|
||
|
||
/* There are a few reasons the wait call above may have
|
||
failed. If the thread manager dies, its children get
|
||
reparented, and this interferes with GDB waiting for
|
||
them, in some cases. Another possibility is that the
|
||
initial thread was not cloned, so calling wait with
|
||
__WCLONE won't find it. I think neither of these should
|
||
occur in modern Linux kernels --- they don't seem to in
|
||
2.0.36. */
|
||
rpid = waitpid (pid, &status, 0);
|
||
if (rpid > 0)
|
||
{
|
||
break;
|
||
}
|
||
if (errno != EINTR)
|
||
perror_with_name ("find_trap/waitpid");
|
||
}
|
||
|
||
if (!WIFSTOPPED(status)) /* Thread has died */
|
||
return 0;
|
||
|
||
if (WSTOPSIG(status) == SIGTRAP)
|
||
if (!stop || found_stop)
|
||
break;
|
||
else
|
||
found_trap = 1;
|
||
else if (WSTOPSIG(status) != SIGSTOP)
|
||
wstatus[last++] = status;
|
||
else if (stop)
|
||
{
|
||
if (found_trap)
|
||
break;
|
||
else
|
||
found_stop = 1;
|
||
}
|
||
}
|
||
|
||
/* Resend any other signals we noticed to the thread, to be received
|
||
when we continue it. */
|
||
while (--last >= 0)
|
||
{
|
||
kill (pid, WSTOPSIG(wstatus[last]));
|
||
}
|
||
|
||
return 1;
|
||
}
|
||
|
||
/* Cleanup stub for save_inferior_pid. */
|
||
static void
|
||
restore_inferior_pid (void *arg)
|
||
{
|
||
int *saved_pid_ptr = arg;
|
||
inferior_pid = *saved_pid_ptr;
|
||
xfree (arg);
|
||
}
|
||
|
||
/* Register a cleanup to restore the value of inferior_pid. */
|
||
static struct cleanup *
|
||
save_inferior_pid (void)
|
||
{
|
||
int *saved_pid_ptr;
|
||
|
||
saved_pid_ptr = xmalloc (sizeof (int));
|
||
*saved_pid_ptr = inferior_pid;
|
||
return make_cleanup (restore_inferior_pid, saved_pid_ptr);
|
||
}
|
||
|
||
static void
|
||
sigchld_handler (int signo)
|
||
{
|
||
/* This handler is used to get an EINTR while doing waitpid()
|
||
when an event is received */
|
||
}
|
||
|
||
/* Have we already collected a wait status for PID in the
|
||
linuxthreads_wait bag? */
|
||
static int
|
||
linuxthreads_pending_status (int pid)
|
||
{
|
||
int i;
|
||
for (i = linuxthreads_wait_last; i >= 0; i--)
|
||
if (linuxthreads_wait_pid[i] == pid)
|
||
return 1;
|
||
return 0;
|
||
}
|
||
|
||
|
||
/* Internal linuxthreads signal management */
|
||
|
||
/* Check in OBJFILE for the variable that holds the number for signal SIG.
|
||
We assume that we've already found other LinuxThreads-ish variables
|
||
in OBJFILE, so we complain if it's required, but not there.
|
||
Return true iff things are okay. */
|
||
static int
|
||
find_signal_var (struct linuxthreads_signal *sig, struct objfile *objfile)
|
||
{
|
||
struct minimal_symbol *ms = lookup_minimal_symbol (sig->var, NULL, objfile);
|
||
|
||
if (! ms)
|
||
{
|
||
if (sig->required)
|
||
{
|
||
fprintf_unfiltered (gdb_stderr,
|
||
"Unable to find linuxthreads symbol \"%s\"\n",
|
||
sig->var);
|
||
return 0;
|
||
}
|
||
else
|
||
{
|
||
sig->addr = 0;
|
||
return 1;
|
||
}
|
||
}
|
||
|
||
sig->addr = SYMBOL_VALUE_ADDRESS (ms);
|
||
|
||
return 1;
|
||
}
|
||
|
||
static int
|
||
find_all_signal_vars (struct objfile *objfile)
|
||
{
|
||
return ( find_signal_var (&linuxthreads_sig_restart, objfile)
|
||
&& find_signal_var (&linuxthreads_sig_cancel, objfile)
|
||
&& find_signal_var (&linuxthreads_sig_debug, objfile));
|
||
}
|
||
|
||
/* A struct complaint isn't appropriate here. */
|
||
static int complained_cannot_determine_thread_signal_number = 0;
|
||
|
||
/* Check to see if the variable holding the signal number for SIG has
|
||
been initialized yet. If it has, tell GDB to pass that signal
|
||
through to the inferior silently. */
|
||
static void
|
||
check_signal_number (struct linuxthreads_signal *sig)
|
||
{
|
||
int num;
|
||
|
||
if (sig->signal)
|
||
/* We already know this signal number. */
|
||
return;
|
||
|
||
if (! sig->addr)
|
||
/* We don't know the variable's address yet. */
|
||
return;
|
||
|
||
if (target_read_memory (sig->addr, (char *)&num, sizeof (num))
|
||
!= 0)
|
||
{
|
||
/* If this happens once, it'll probably happen for all the
|
||
signals, so only complain once. */
|
||
if (! complained_cannot_determine_thread_signal_number)
|
||
warning ("Cannot determine thread signal number; "
|
||
"GDB may report spurious signals.");
|
||
complained_cannot_determine_thread_signal_number = 1;
|
||
return;
|
||
}
|
||
|
||
if (num == 0)
|
||
/* It hasn't been initialized yet. */
|
||
return;
|
||
|
||
/* We know sig->signal was zero, and is becoming non-zero, so it's
|
||
okay to sample GDB's original settings. */
|
||
sig->signal = num;
|
||
sig->stop = signal_stop_update (target_signal_from_host (num), 0);
|
||
sig->print = signal_print_update (target_signal_from_host (num), 0);
|
||
}
|
||
|
||
void
|
||
check_all_signal_numbers (void)
|
||
{
|
||
/* If this isn't a LinuxThreads program, quit early. */
|
||
if (! linuxthreads_max)
|
||
return;
|
||
|
||
check_signal_number (&linuxthreads_sig_restart);
|
||
check_signal_number (&linuxthreads_sig_cancel);
|
||
check_signal_number (&linuxthreads_sig_debug);
|
||
|
||
/* handle linuxthread exit */
|
||
if (linuxthreads_sig_debug.signal
|
||
|| linuxthreads_sig_restart.signal)
|
||
{
|
||
struct sigaction sact;
|
||
|
||
sact.sa_handler = sigchld_handler;
|
||
sigemptyset(&sact.sa_mask);
|
||
sact.sa_flags = 0;
|
||
|
||
if (linuxthreads_sig_debug.signal > 0)
|
||
sigaction(linuxthreads_sig_cancel.signal, &sact, NULL);
|
||
else
|
||
sigaction(linuxthreads_sig_restart.signal, &sact, NULL);
|
||
}
|
||
}
|
||
|
||
|
||
/* Restore GDB's original settings for SIG.
|
||
This should only be called when we're no longer sure if we're
|
||
talking to an executable that uses LinuxThreads, so we clear the
|
||
signal number and variable address too. */
|
||
static void
|
||
restore_signal (struct linuxthreads_signal *sig)
|
||
{
|
||
if (! sig->signal)
|
||
return;
|
||
|
||
/* We know sig->signal was non-zero, and is becoming zero, so it's
|
||
okay to restore GDB's original settings. */
|
||
signal_stop_update (target_signal_from_host (sig->signal), sig->stop);
|
||
signal_print_update (target_signal_from_host (sig->signal), sig->print);
|
||
|
||
sig->signal = 0;
|
||
sig->addr = 0;
|
||
}
|
||
|
||
|
||
/* Restore GDB's original settings for all LinuxThreads signals.
|
||
This should only be called when we're no longer sure if we're
|
||
talking to an executable that uses LinuxThreads, so we clear the
|
||
signal number and variable address too. */
|
||
static void
|
||
restore_all_signals (void)
|
||
{
|
||
restore_signal (&linuxthreads_sig_restart);
|
||
restore_signal (&linuxthreads_sig_cancel);
|
||
restore_signal (&linuxthreads_sig_debug);
|
||
|
||
/* If it happens again, we should complain again. */
|
||
complained_cannot_determine_thread_signal_number = 0;
|
||
}
|
||
|
||
|
||
|
||
|
||
/* Apply FUNC to the pid of each active thread. This consults the
|
||
inferior's handle table to find active threads.
|
||
|
||
If ALL is non-zero, process all threads.
|
||
If ALL is zero, skip threads with pending status. */
|
||
static void
|
||
iterate_active_threads (void (*func) (int), int all)
|
||
{
|
||
CORE_ADDR descr;
|
||
int pid;
|
||
int i;
|
||
int num;
|
||
|
||
read_memory (linuxthreads_num, (char *)&num, sizeof (int));
|
||
|
||
for (i = 0; i < linuxthreads_max && num > 0; i++)
|
||
{
|
||
read_memory (linuxthreads_handles +
|
||
linuxthreads_sizeof_handle * i + linuxthreads_offset_descr,
|
||
(char *)&descr, sizeof (void *));
|
||
if (descr)
|
||
{
|
||
num--;
|
||
read_memory (descr + linuxthreads_offset_pid,
|
||
(char *)&pid, sizeof (pid_t));
|
||
if (pid > 0 && pid != linuxthreads_manager_pid
|
||
&& (all || (!linuxthreads_pending_status (pid))))
|
||
(*func)(pid);
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Insert a thread breakpoint at linuxthreads_breakpoint_addr.
|
||
This is the worker function for linuxthreads_insert_breakpoint,
|
||
which passes it to iterate_active_threads. */
|
||
static void
|
||
insert_breakpoint (int pid)
|
||
{
|
||
int j;
|
||
|
||
/* Remove (if any) the positive zombie breakpoint. */
|
||
for (j = linuxthreads_breakpoint_last; j >= 0; j--)
|
||
if (linuxthreads_breakpoint_zombie[j].pid == pid)
|
||
{
|
||
if ((linuxthreads_breakpoint_zombie[j].pc - DECR_PC_AFTER_BREAK
|
||
== linuxthreads_breakpoint_addr)
|
||
&& !linuxthreads_breakpoint_zombie[j].step)
|
||
REMOVE_BREAKPOINT_ZOMBIE(j);
|
||
break;
|
||
}
|
||
}
|
||
|
||
/* Note that we're about to remove a thread breakpoint at
|
||
linuxthreads_breakpoint_addr.
|
||
|
||
This is the worker function for linuxthreads_remove_breakpoint,
|
||
which passes it to iterate_active_threads. The actual work of
|
||
overwriting the breakpoint instruction is done by
|
||
child_ops.to_remove_breakpoint; here, we simply create a zombie
|
||
breakpoint if the thread's PC is pointing at the breakpoint being
|
||
removed. */
|
||
static void
|
||
remove_breakpoint (int pid)
|
||
{
|
||
int j;
|
||
|
||
/* Insert a positive zombie breakpoint (if needed). */
|
||
for (j = 0; j <= linuxthreads_breakpoint_last; j++)
|
||
if (linuxthreads_breakpoint_zombie[j].pid == pid)
|
||
break;
|
||
|
||
if (in_thread_list (pid) && linuxthreads_thread_alive (pid))
|
||
{
|
||
CORE_ADDR pc = read_pc_pid (pid);
|
||
if (linuxthreads_breakpoint_addr == pc - DECR_PC_AFTER_BREAK
|
||
&& j > linuxthreads_breakpoint_last)
|
||
{
|
||
linuxthreads_breakpoint_zombie[j].pid = pid;
|
||
linuxthreads_breakpoint_zombie[j].pc = pc;
|
||
linuxthreads_breakpoint_zombie[j].step = 0;
|
||
linuxthreads_breakpoint_last++;
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Kill a thread */
|
||
static void
|
||
kill_thread (int pid)
|
||
{
|
||
if (in_thread_list (pid))
|
||
{
|
||
ptrace (PT_KILL, pid, (PTRACE_ARG3_TYPE) 0, 0);
|
||
}
|
||
else
|
||
{
|
||
kill (pid, SIGKILL);
|
||
}
|
||
}
|
||
|
||
/* Resume a thread */
|
||
static void
|
||
resume_thread (int pid)
|
||
{
|
||
if (pid != inferior_pid
|
||
&& in_thread_list (pid)
|
||
&& linuxthreads_thread_alive (pid))
|
||
{
|
||
if (pid == linuxthreads_step_pid)
|
||
{
|
||
child_resume (pid, 1, linuxthreads_step_signo);
|
||
}
|
||
else
|
||
{
|
||
child_resume (pid, 0, TARGET_SIGNAL_0);
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Detach a thread */
|
||
static void
|
||
detach_thread (int pid)
|
||
{
|
||
if (in_thread_list (pid) && linuxthreads_thread_alive (pid))
|
||
{
|
||
/* Remove pending SIGTRAP and SIGSTOP */
|
||
linuxthreads_find_trap (pid, 1);
|
||
|
||
inferior_pid = pid;
|
||
detach (TARGET_SIGNAL_0);
|
||
inferior_pid = linuxthreads_manager_pid;
|
||
}
|
||
}
|
||
|
||
/* Attach a thread */
|
||
void
|
||
attach_thread (int pid)
|
||
{
|
||
if (ptrace (PT_ATTACH, pid, (PTRACE_ARG3_TYPE) 0, 0) != 0)
|
||
perror_with_name ("attach_thread");
|
||
}
|
||
|
||
/* Stop a thread */
|
||
static void
|
||
stop_thread (int pid)
|
||
{
|
||
if (pid != inferior_pid)
|
||
{
|
||
if (in_thread_list (pid))
|
||
{
|
||
kill (pid, SIGSTOP);
|
||
}
|
||
else if (ptrace (PT_ATTACH, pid, (PTRACE_ARG3_TYPE) 0, 0) == 0)
|
||
{
|
||
if (!linuxthreads_attach_pending)
|
||
printf_filtered ("[New %s]\n", target_pid_to_str (pid));
|
||
add_thread (pid);
|
||
if (linuxthreads_sig_debug.signal)
|
||
{
|
||
/* After a new thread in glibc 2.1 signals gdb its existence,
|
||
it suspends itself and wait for linuxthreads_sig_restart,
|
||
now we can wake it up. */
|
||
kill (pid, linuxthreads_sig_restart.signal);
|
||
}
|
||
}
|
||
else
|
||
perror_with_name ("ptrace in stop_thread");
|
||
}
|
||
}
|
||
|
||
/* Wait for a thread */
|
||
static void
|
||
wait_thread (int pid)
|
||
{
|
||
int status;
|
||
int rpid;
|
||
|
||
if (pid != inferior_pid && in_thread_list (pid))
|
||
{
|
||
/* loop as long as errno == EINTR:
|
||
waitpid syscall may be aborted if GDB receives a signal.
|
||
FIXME: EINTR handling should no longer be necessary here, since
|
||
we now block SIGCHLD except during an explicit sigsuspend call. */
|
||
for (;;)
|
||
{
|
||
/* Get first pid status. */
|
||
rpid = waitpid(pid, &status, __WCLONE);
|
||
if (rpid > 0)
|
||
{
|
||
break;
|
||
}
|
||
if (errno == EINTR)
|
||
{
|
||
continue;
|
||
}
|
||
|
||
/* There are two reasons this might have failed:
|
||
|
||
1) PID is the initial thread, which wasn't cloned, so
|
||
passing the __WCLONE flag to waitpid prevented us from
|
||
finding it.
|
||
|
||
2) The manager thread is the parent of all but the
|
||
initial thread; if it dies, the children will all be
|
||
reparented to init, which will wait for them. This means
|
||
our call to waitpid won't find them.
|
||
|
||
Actually, based on a casual look at the 2.0.36 kernel
|
||
code, I don't think either of these cases happen. But I
|
||
don't have things set up for remotely debugging the
|
||
kernel, so I'm not sure. And perhaps older kernels
|
||
didn't work. */
|
||
rpid = waitpid(pid, &status, 0);
|
||
if (rpid > 0)
|
||
{
|
||
break;
|
||
}
|
||
if (errno != EINTR && linuxthreads_thread_alive (pid))
|
||
perror_with_name ("wait_thread/waitpid");
|
||
|
||
/* the thread is dead. */
|
||
return;
|
||
}
|
||
if (!WIFSTOPPED(status) || WSTOPSIG(status) != SIGSTOP)
|
||
{
|
||
linuxthreads_wait_pid[++linuxthreads_wait_last] = pid;
|
||
linuxthreads_wait_status[linuxthreads_wait_last] = status;
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Walk through the linuxthreads handles in order to detect all
|
||
threads and stop them */
|
||
static void
|
||
update_stop_threads (int test_pid)
|
||
{
|
||
struct cleanup *old_chain = NULL;
|
||
|
||
check_all_signal_numbers ();
|
||
|
||
if (linuxthreads_manager_pid == 0)
|
||
{
|
||
if (linuxthreads_manager)
|
||
{
|
||
if (test_pid > 0 && test_pid != inferior_pid)
|
||
{
|
||
old_chain = save_inferior_pid ();
|
||
inferior_pid = test_pid;
|
||
}
|
||
read_memory (linuxthreads_manager,
|
||
(char *)&linuxthreads_manager_pid, sizeof (pid_t));
|
||
}
|
||
if (linuxthreads_initial)
|
||
{
|
||
if (test_pid > 0 && test_pid != inferior_pid)
|
||
{
|
||
old_chain = save_inferior_pid ();
|
||
inferior_pid = test_pid;
|
||
}
|
||
read_memory(linuxthreads_initial,
|
||
(char *)&linuxthreads_initial_pid, sizeof (pid_t));
|
||
}
|
||
}
|
||
|
||
if (linuxthreads_manager_pid != 0)
|
||
{
|
||
if (old_chain == NULL && test_pid > 0 &&
|
||
test_pid != inferior_pid && linuxthreads_thread_alive (test_pid))
|
||
{
|
||
old_chain = save_inferior_pid ();
|
||
inferior_pid = test_pid;
|
||
}
|
||
|
||
if (linuxthreads_thread_alive (inferior_pid))
|
||
{
|
||
if (test_pid > 0)
|
||
{
|
||
if (test_pid != linuxthreads_manager_pid
|
||
&& !linuxthreads_pending_status (linuxthreads_manager_pid))
|
||
{
|
||
stop_thread (linuxthreads_manager_pid);
|
||
wait_thread (linuxthreads_manager_pid);
|
||
}
|
||
if (!in_thread_list (test_pid))
|
||
{
|
||
if (!linuxthreads_attach_pending)
|
||
printf_filtered ("[New %s]\n",
|
||
target_pid_to_str (test_pid));
|
||
add_thread (test_pid);
|
||
if (linuxthreads_sig_debug.signal
|
||
&& inferior_pid == test_pid)
|
||
{
|
||
/* After a new thread in glibc 2.1 signals gdb its
|
||
existence, it suspends itself and wait for
|
||
linuxthreads_sig_restart, now we can wake it up. */
|
||
kill (test_pid, linuxthreads_sig_restart.signal);
|
||
}
|
||
}
|
||
}
|
||
iterate_active_threads (stop_thread, 0);
|
||
iterate_active_threads (wait_thread, 0);
|
||
}
|
||
}
|
||
|
||
if (old_chain != NULL)
|
||
do_cleanups (old_chain);
|
||
}
|
||
|
||
/* This routine is called whenever a new symbol table is read in, or
|
||
when all symbol tables are removed. linux-thread event handling
|
||
can only be initialized when we find the right variables in
|
||
libpthread.so. Since it's a shared library, those variables don't
|
||
show up until the library gets mapped and the symbol table is read
|
||
in. */
|
||
|
||
/* This new_objfile event is now managed by a chained function pointer.
|
||
* It is the callee's responsability to call the next client on the chain.
|
||
*/
|
||
|
||
/* Saved pointer to previous owner of the new_objfile event. */
|
||
static void (*target_new_objfile_chain) (struct objfile *);
|
||
|
||
void
|
||
linuxthreads_new_objfile (struct objfile *objfile)
|
||
{
|
||
struct minimal_symbol *ms;
|
||
|
||
/* Call predecessor on chain, if any.
|
||
Calling the new module first allows it to dominate,
|
||
if it finds its compatible libraries. */
|
||
|
||
if (target_new_objfile_chain)
|
||
target_new_objfile_chain (objfile);
|
||
|
||
if (!objfile)
|
||
{
|
||
/* We're starting an entirely new executable, so we can no
|
||
longer be sure that it uses LinuxThreads. Restore the signal
|
||
flags to their original states. */
|
||
restore_all_signals ();
|
||
|
||
/* Indicate that we don't know anything's address any more. */
|
||
linuxthreads_max = 0;
|
||
|
||
goto quit;
|
||
}
|
||
|
||
/* If we've already found our variables in another objfile, don't
|
||
bother looking for them again. */
|
||
if (linuxthreads_max)
|
||
goto quit;
|
||
|
||
if (! lookup_minimal_symbol ("__pthread_initial_thread", NULL, objfile))
|
||
/* This object file isn't the pthreads library. */
|
||
goto quit;
|
||
|
||
if ((ms = lookup_minimal_symbol ("__pthread_threads_debug",
|
||
NULL, objfile)) == NULL)
|
||
{
|
||
/* The debugging-aware libpthreads is not present in this objfile */
|
||
warning ("\
|
||
This program seems to use POSIX threads, but the thread library used\n\
|
||
does not support debugging. This may make using GDB difficult. Don't\n\
|
||
set breakpoints or single-step through code that might be executed by\n\
|
||
any thread other than the main thread.");
|
||
goto quit;
|
||
}
|
||
linuxthreads_debug = SYMBOL_VALUE_ADDRESS (ms);
|
||
|
||
/* Read internal structures configuration */
|
||
if ((ms = lookup_minimal_symbol ("__pthread_sizeof_handle",
|
||
NULL, objfile)) == NULL
|
||
|| target_read_memory (SYMBOL_VALUE_ADDRESS (ms),
|
||
(char *)&linuxthreads_sizeof_handle,
|
||
sizeof (linuxthreads_sizeof_handle)) != 0)
|
||
{
|
||
fprintf_unfiltered (gdb_stderr,
|
||
"Unable to find linuxthreads symbol \"%s\"\n",
|
||
"__pthread_sizeof_handle");
|
||
goto quit;
|
||
}
|
||
|
||
if ((ms = lookup_minimal_symbol ("__pthread_offsetof_descr",
|
||
NULL, objfile)) == NULL
|
||
|| target_read_memory (SYMBOL_VALUE_ADDRESS (ms),
|
||
(char *)&linuxthreads_offset_descr,
|
||
sizeof (linuxthreads_offset_descr)) != 0)
|
||
{
|
||
fprintf_unfiltered (gdb_stderr,
|
||
"Unable to find linuxthreads symbol \"%s\"\n",
|
||
"__pthread_offsetof_descr");
|
||
goto quit;
|
||
}
|
||
|
||
if ((ms = lookup_minimal_symbol ("__pthread_offsetof_pid",
|
||
NULL, objfile)) == NULL
|
||
|| target_read_memory (SYMBOL_VALUE_ADDRESS (ms),
|
||
(char *)&linuxthreads_offset_pid,
|
||
sizeof (linuxthreads_offset_pid)) != 0)
|
||
{
|
||
fprintf_unfiltered (gdb_stderr,
|
||
"Unable to find linuxthreads symbol \"%s\"\n",
|
||
"__pthread_offsetof_pid");
|
||
goto quit;
|
||
}
|
||
|
||
if (! find_all_signal_vars (objfile))
|
||
goto quit;
|
||
|
||
/* Read adresses of internal structures to access */
|
||
if ((ms = lookup_minimal_symbol ("__pthread_handles",
|
||
NULL, objfile)) == NULL)
|
||
{
|
||
fprintf_unfiltered (gdb_stderr,
|
||
"Unable to find linuxthreads symbol \"%s\"\n",
|
||
"__pthread_handles");
|
||
goto quit;
|
||
}
|
||
linuxthreads_handles = SYMBOL_VALUE_ADDRESS (ms);
|
||
|
||
if ((ms = lookup_minimal_symbol ("__pthread_handles_num",
|
||
NULL, objfile)) == NULL)
|
||
{
|
||
fprintf_unfiltered (gdb_stderr,
|
||
"Unable to find linuxthreads symbol \"%s\"\n",
|
||
"__pthread_handles_num");
|
||
goto quit;
|
||
}
|
||
linuxthreads_num = SYMBOL_VALUE_ADDRESS (ms);
|
||
|
||
if ((ms = lookup_minimal_symbol ("__pthread_manager_thread",
|
||
NULL, objfile)) == NULL)
|
||
{
|
||
fprintf_unfiltered (gdb_stderr,
|
||
"Unable to find linuxthreads symbol \"%s\"\n",
|
||
"__pthread_manager_thread");
|
||
goto quit;
|
||
}
|
||
linuxthreads_manager = SYMBOL_VALUE_ADDRESS (ms) + linuxthreads_offset_pid;
|
||
|
||
if ((ms = lookup_minimal_symbol ("__pthread_initial_thread",
|
||
NULL, objfile)) == NULL)
|
||
{
|
||
fprintf_unfiltered (gdb_stderr,
|
||
"Unable to find linuxthreads symbol \"%s\"\n",
|
||
"__pthread_initial_thread");
|
||
goto quit;
|
||
}
|
||
linuxthreads_initial = SYMBOL_VALUE_ADDRESS (ms) + linuxthreads_offset_pid;
|
||
|
||
/* Search for this last, so it won't be set to a non-zero value unless
|
||
we successfully found all the symbols above. */
|
||
if ((ms = lookup_minimal_symbol ("__pthread_threads_max",
|
||
NULL, objfile)) == NULL
|
||
|| target_read_memory (SYMBOL_VALUE_ADDRESS (ms),
|
||
(char *)&linuxthreads_max,
|
||
sizeof (linuxthreads_max)) != 0)
|
||
{
|
||
fprintf_unfiltered (gdb_stderr,
|
||
"Unable to find linuxthreads symbol \"%s\"\n",
|
||
"__pthread_threads_max");
|
||
goto quit;
|
||
}
|
||
|
||
/* Allocate gdb internal structures */
|
||
linuxthreads_wait_pid =
|
||
(int *) xmalloc (sizeof (int) * (linuxthreads_max + 1));
|
||
linuxthreads_wait_status =
|
||
(int *) xmalloc (sizeof (int) * (linuxthreads_max + 1));
|
||
linuxthreads_breakpoint_zombie = (struct linuxthreads_breakpoint *)
|
||
xmalloc (sizeof (struct linuxthreads_breakpoint) * (linuxthreads_max + 1));
|
||
|
||
if (inferior_pid &&
|
||
!linuxthreads_attach_pending &&
|
||
!using_thread_db) /* suppressed by thread_db module */
|
||
{
|
||
int on = 1;
|
||
|
||
target_write_memory (linuxthreads_debug, (char *)&on, sizeof (on));
|
||
linuxthreads_attach_pending = 1;
|
||
update_stop_threads (inferior_pid);
|
||
linuxthreads_attach_pending = 0;
|
||
}
|
||
|
||
check_all_signal_numbers ();
|
||
|
||
quit:
|
||
}
|
||
|
||
/* If we have switched threads from a one that stopped at breakpoint,
|
||
return 1 otherwise 0.
|
||
|
||
Note that this implementation is potentially redundant now that
|
||
default_prepare_to_proceed() has been added. */
|
||
|
||
int
|
||
linuxthreads_prepare_to_proceed (int step)
|
||
{
|
||
if (!linuxthreads_max
|
||
|| !linuxthreads_manager_pid
|
||
|| !linuxthreads_breakpoint_pid
|
||
|| !breakpoint_here_p (read_pc_pid (linuxthreads_breakpoint_pid)))
|
||
return 0;
|
||
|
||
if (step)
|
||
{
|
||
/* Mark the current inferior as single stepping process. */
|
||
linuxthreads_step_pid = inferior_pid;
|
||
}
|
||
|
||
linuxthreads_inferior_pid = linuxthreads_breakpoint_pid;
|
||
return linuxthreads_breakpoint_pid;
|
||
}
|
||
|
||
/* Convert a pid to printable form. */
|
||
|
||
char *
|
||
linuxthreads_pid_to_str (int pid)
|
||
{
|
||
static char buf[100];
|
||
|
||
sprintf (buf, "%s %d%s", linuxthreads_max ? "Thread" : "Pid", pid,
|
||
(pid == linuxthreads_manager_pid) ? " (manager thread)"
|
||
: (pid == linuxthreads_initial_pid) ? " (initial thread)"
|
||
: "");
|
||
|
||
return buf;
|
||
}
|
||
|
||
/* Attach to process PID, then initialize for debugging it
|
||
and wait for the trace-trap that results from attaching. */
|
||
|
||
static void
|
||
linuxthreads_attach (char *args, int from_tty)
|
||
{
|
||
if (!args)
|
||
error_no_arg ("process-id to attach");
|
||
|
||
push_target (&linuxthreads_ops);
|
||
linuxthreads_breakpoints_inserted = 1;
|
||
linuxthreads_breakpoint_last = -1;
|
||
linuxthreads_wait_last = -1;
|
||
WSETSTOP (linuxthreads_exit_status, 0);
|
||
|
||
child_ops.to_attach (args, from_tty);
|
||
|
||
if (linuxthreads_max)
|
||
linuxthreads_attach_pending = 1;
|
||
}
|
||
|
||
/* Take a program previously attached to and detaches it.
|
||
The program resumes execution and will no longer stop
|
||
on signals, etc. We'd better not have left any breakpoints
|
||
in the program or it'll die when it hits one. For this
|
||
to work, it may be necessary for the process to have been
|
||
previously attached. It *might* work if the program was
|
||
started via the normal ptrace (PTRACE_TRACEME). */
|
||
|
||
static void
|
||
linuxthreads_detach (char *args, int from_tty)
|
||
{
|
||
if (linuxthreads_max)
|
||
{
|
||
int i;
|
||
int pid;
|
||
int off = 0;
|
||
target_write_memory (linuxthreads_debug, (char *)&off, sizeof (off));
|
||
|
||
/* Walk through linuxthreads array in order to detach known threads. */
|
||
if (linuxthreads_manager_pid != 0)
|
||
{
|
||
/* Get rid of all positive zombie breakpoints. */
|
||
for (i = 0; i <= linuxthreads_breakpoint_last; i++)
|
||
{
|
||
if (linuxthreads_breakpoint_zombie[i].step)
|
||
continue;
|
||
|
||
pid = linuxthreads_breakpoint_zombie[i].pid;
|
||
if (!linuxthreads_thread_alive (pid))
|
||
continue;
|
||
|
||
if (linuxthreads_breakpoint_zombie[i].pc != read_pc_pid (pid))
|
||
continue;
|
||
|
||
/* Continue in STEP mode until the thread pc has moved or
|
||
until SIGTRAP is found on the same PC. */
|
||
if (linuxthreads_find_trap (pid, 0)
|
||
&& linuxthreads_breakpoint_zombie[i].pc == read_pc_pid (pid))
|
||
write_pc_pid (linuxthreads_breakpoint_zombie[i].pc
|
||
- DECR_PC_AFTER_BREAK, pid);
|
||
}
|
||
|
||
/* Detach thread after thread. */
|
||
inferior_pid = linuxthreads_manager_pid;
|
||
iterate_active_threads (detach_thread, 1);
|
||
|
||
/* Remove pending SIGTRAP and SIGSTOP */
|
||
linuxthreads_find_trap (inferior_pid, 1);
|
||
|
||
linuxthreads_wait_last = -1;
|
||
WSETSTOP (linuxthreads_exit_status, 0);
|
||
}
|
||
|
||
linuxthreads_inferior_pid = 0;
|
||
linuxthreads_breakpoint_pid = 0;
|
||
linuxthreads_step_pid = 0;
|
||
linuxthreads_step_signo = TARGET_SIGNAL_0;
|
||
linuxthreads_manager_pid = 0;
|
||
linuxthreads_initial_pid = 0;
|
||
linuxthreads_attach_pending = 0;
|
||
init_thread_list (); /* Destroy thread info */
|
||
}
|
||
|
||
child_ops.to_detach (args, from_tty);
|
||
|
||
unpush_target (&linuxthreads_ops);
|
||
}
|
||
|
||
/* Resume execution of process PID. If STEP is nozero, then
|
||
just single step it. If SIGNAL is nonzero, restart it with that
|
||
signal activated. */
|
||
|
||
static void
|
||
linuxthreads_resume (int pid, int step, enum target_signal signo)
|
||
{
|
||
if (!linuxthreads_max || stop_soon_quietly || linuxthreads_manager_pid == 0)
|
||
{
|
||
child_ops.to_resume (pid, step, signo);
|
||
}
|
||
else
|
||
{
|
||
int rpid;
|
||
if (linuxthreads_inferior_pid)
|
||
{
|
||
/* Prepare resume of the last thread that hit a breakpoint */
|
||
linuxthreads_breakpoints_inserted = 0;
|
||
rpid = linuxthreads_inferior_pid;
|
||
linuxthreads_step_signo = signo;
|
||
}
|
||
else
|
||
{
|
||
struct cleanup *old_chain = NULL;
|
||
int i;
|
||
|
||
if (pid < 0)
|
||
{
|
||
linuxthreads_step_pid = step ? inferior_pid : 0;
|
||
linuxthreads_step_signo = signo;
|
||
rpid = inferior_pid;
|
||
}
|
||
else
|
||
rpid = pid;
|
||
|
||
if (pid < 0 || !step)
|
||
{
|
||
linuxthreads_breakpoints_inserted = 1;
|
||
|
||
/* Walk through linuxthreads array in order to resume threads */
|
||
if (pid >= 0 && inferior_pid != pid)
|
||
{
|
||
old_chain = save_inferior_pid ();
|
||
inferior_pid = pid;
|
||
}
|
||
|
||
iterate_active_threads (resume_thread, 0);
|
||
if (linuxthreads_manager_pid != inferior_pid
|
||
&& !linuxthreads_pending_status (linuxthreads_manager_pid))
|
||
resume_thread (linuxthreads_manager_pid);
|
||
}
|
||
else
|
||
linuxthreads_breakpoints_inserted = 0;
|
||
|
||
/* Deal with zombie breakpoint */
|
||
for (i = 0; i <= linuxthreads_breakpoint_last; i++)
|
||
if (linuxthreads_breakpoint_zombie[i].pid == rpid)
|
||
{
|
||
if (linuxthreads_breakpoint_zombie[i].pc != read_pc_pid (rpid))
|
||
{
|
||
/* The current pc is out of zombie breakpoint. */
|
||
REMOVE_BREAKPOINT_ZOMBIE(i);
|
||
}
|
||
break;
|
||
}
|
||
|
||
if (old_chain != NULL)
|
||
do_cleanups (old_chain);
|
||
}
|
||
|
||
/* Resume initial thread. */
|
||
/* [unles it has a wait event pending] */
|
||
if (!linuxthreads_pending_status (rpid))
|
||
{
|
||
child_ops.to_resume (rpid, step, signo);
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Abstract out the child_wait functionality. */
|
||
int
|
||
linux_child_wait (int pid, int *rpid, int *status)
|
||
{
|
||
int save_errno;
|
||
|
||
/* Note: inftarg has these inside the loop. */
|
||
set_sigint_trap (); /* Causes SIGINT to be passed on to the
|
||
attached process. */
|
||
set_sigio_trap ();
|
||
|
||
errno = save_errno = 0;
|
||
for (;;)
|
||
{
|
||
errno = 0;
|
||
*rpid = waitpid (pid, status, __WCLONE | WNOHANG);
|
||
save_errno = errno;
|
||
|
||
if (*rpid > 0)
|
||
{
|
||
/* Got an event -- break out */
|
||
break;
|
||
}
|
||
if (errno == EINTR) /* interrupted by signal, try again */
|
||
{
|
||
continue;
|
||
}
|
||
|
||
errno = 0;
|
||
*rpid = waitpid (pid, status, WNOHANG);
|
||
if (*rpid > 0)
|
||
{
|
||
/* Got an event -- break out */
|
||
break;
|
||
}
|
||
if (errno == EINTR)
|
||
{
|
||
continue;
|
||
}
|
||
if (errno != 0 && save_errno != 0)
|
||
{
|
||
break;
|
||
}
|
||
sigsuspend(&linuxthreads_block_mask);
|
||
}
|
||
clear_sigio_trap ();
|
||
clear_sigint_trap ();
|
||
|
||
return errno ? errno : save_errno;
|
||
}
|
||
|
||
|
||
/* Wait for any threads to stop. We may have to convert PID from a thread id
|
||
to a LWP id, and vice versa on the way out. */
|
||
|
||
static int
|
||
linuxthreads_wait (int pid, struct target_waitstatus *ourstatus)
|
||
{
|
||
int status;
|
||
int rpid;
|
||
int i;
|
||
int last;
|
||
int *wstatus;
|
||
|
||
if (linuxthreads_max && !linuxthreads_breakpoints_inserted)
|
||
wstatus = alloca (LINUXTHREAD_NSIG * sizeof (int));
|
||
|
||
/* See if the inferior has chosen values for its signals yet. By
|
||
checking for them here, we can be sure we've updated GDB's signal
|
||
handling table before the inferior ever gets one of them. (Well,
|
||
before we notice, anyway.) */
|
||
check_all_signal_numbers ();
|
||
|
||
for (;;)
|
||
{
|
||
if (!linuxthreads_max)
|
||
rpid = 0;
|
||
else if (!linuxthreads_breakpoints_inserted)
|
||
{
|
||
if (linuxthreads_inferior_pid)
|
||
pid = linuxthreads_inferior_pid;
|
||
else if (pid < 0)
|
||
pid = inferior_pid;
|
||
last = rpid = 0;
|
||
}
|
||
else if (pid < 0 && linuxthreads_wait_last >= 0)
|
||
{
|
||
status = linuxthreads_wait_status[linuxthreads_wait_last];
|
||
rpid = linuxthreads_wait_pid[linuxthreads_wait_last--];
|
||
}
|
||
else if (pid > 0 && linuxthreads_pending_status (pid))
|
||
{
|
||
for (i = linuxthreads_wait_last; i >= 0; i--)
|
||
if (linuxthreads_wait_pid[i] == pid)
|
||
break;
|
||
if (i < 0)
|
||
rpid = 0;
|
||
else
|
||
{
|
||
status = linuxthreads_wait_status[i];
|
||
rpid = pid;
|
||
if (i < linuxthreads_wait_last)
|
||
{
|
||
linuxthreads_wait_status[i] =
|
||
linuxthreads_wait_status[linuxthreads_wait_last];
|
||
linuxthreads_wait_pid[i] =
|
||
linuxthreads_wait_pid[linuxthreads_wait_last];
|
||
}
|
||
linuxthreads_wait_last--;
|
||
}
|
||
}
|
||
else
|
||
rpid = 0;
|
||
|
||
if (rpid == 0)
|
||
{
|
||
int save_errno;
|
||
|
||
save_errno = linux_child_wait (pid, &rpid, &status);
|
||
|
||
if (rpid == -1)
|
||
{
|
||
if (WIFEXITED(linuxthreads_exit_status))
|
||
{
|
||
store_waitstatus (ourstatus, linuxthreads_exit_status);
|
||
return inferior_pid;
|
||
}
|
||
else
|
||
{
|
||
fprintf_unfiltered
|
||
(gdb_stderr, "Child process unexpectedly missing: %s.\n",
|
||
safe_strerror (save_errno));
|
||
/* Claim it exited with unknown signal. */
|
||
ourstatus->kind = TARGET_WAITKIND_SIGNALLED;
|
||
ourstatus->value.sig = TARGET_SIGNAL_UNKNOWN;
|
||
return -1;
|
||
}
|
||
}
|
||
|
||
/* We have now gotten a new event from waitpid above. */
|
||
|
||
/* Signals arrive in any order. So get all signals until
|
||
SIGTRAP and resend previous ones to be held after. */
|
||
if (linuxthreads_max
|
||
&& !linuxthreads_breakpoints_inserted
|
||
&& WIFSTOPPED(status))
|
||
if (WSTOPSIG(status) == SIGTRAP)
|
||
{
|
||
while (--last >= 0)
|
||
{
|
||
kill (rpid, WSTOPSIG(wstatus[last]));
|
||
}
|
||
|
||
/* insert negative zombie breakpoint */
|
||
for (i = 0; i <= linuxthreads_breakpoint_last; i++)
|
||
if (linuxthreads_breakpoint_zombie[i].pid == rpid)
|
||
break;
|
||
if (i > linuxthreads_breakpoint_last)
|
||
{
|
||
linuxthreads_breakpoint_zombie[i].pid = rpid;
|
||
linuxthreads_breakpoint_last++;
|
||
}
|
||
linuxthreads_breakpoint_zombie[i].pc = read_pc_pid (rpid);
|
||
linuxthreads_breakpoint_zombie[i].step = 1;
|
||
}
|
||
else
|
||
{
|
||
if (WSTOPSIG(status) != SIGSTOP)
|
||
{
|
||
for (i = 0; i < last; i++)
|
||
if (wstatus[i] == status)
|
||
break;
|
||
if (i >= last)
|
||
{
|
||
wstatus[last++] = status;
|
||
}
|
||
}
|
||
child_resume (rpid, 1, TARGET_SIGNAL_0);
|
||
continue;
|
||
}
|
||
if (linuxthreads_inferior_pid)
|
||
linuxthreads_inferior_pid = 0;
|
||
}
|
||
|
||
if (linuxthreads_max && !stop_soon_quietly)
|
||
{
|
||
if (linuxthreads_max
|
||
&& WIFSTOPPED(status)
|
||
&& WSTOPSIG(status) == SIGSTOP)
|
||
{
|
||
/* Skip SIGSTOP signals. */
|
||
if (!linuxthreads_pending_status (rpid))
|
||
{
|
||
if (linuxthreads_step_pid == rpid)
|
||
{
|
||
child_resume (rpid, 1, linuxthreads_step_signo);
|
||
}
|
||
else
|
||
{
|
||
child_resume (rpid, 0, TARGET_SIGNAL_0);
|
||
}
|
||
}
|
||
continue;
|
||
}
|
||
|
||
/* Do no report exit status of cloned threads. */
|
||
if (WIFEXITED(status))
|
||
{
|
||
if (rpid == linuxthreads_initial_pid)
|
||
linuxthreads_exit_status = status;
|
||
|
||
/* Remove any zombie breakpoint. */
|
||
for (i = 0; i <= linuxthreads_breakpoint_last; i++)
|
||
if (linuxthreads_breakpoint_zombie[i].pid == rpid)
|
||
{
|
||
REMOVE_BREAKPOINT_ZOMBIE(i);
|
||
break;
|
||
}
|
||
if (pid > 0)
|
||
pid = -1;
|
||
continue;
|
||
}
|
||
|
||
/* Deal with zombie breakpoint */
|
||
for (i = 0; i <= linuxthreads_breakpoint_last; i++)
|
||
if (linuxthreads_breakpoint_zombie[i].pid == rpid)
|
||
break;
|
||
|
||
if (i <= linuxthreads_breakpoint_last)
|
||
{
|
||
/* There is a potential zombie breakpoint */
|
||
if (WIFEXITED(status)
|
||
|| linuxthreads_breakpoint_zombie[i].pc != read_pc_pid (rpid))
|
||
{
|
||
/* The current pc is out of zombie breakpoint. */
|
||
REMOVE_BREAKPOINT_ZOMBIE(i);
|
||
}
|
||
else if (!linuxthreads_breakpoint_zombie[i].step
|
||
&& WIFSTOPPED(status) && WSTOPSIG(status) == SIGTRAP)
|
||
{
|
||
/* This is a real one ==> decrement PC and restart. */
|
||
write_pc_pid (linuxthreads_breakpoint_zombie[i].pc
|
||
- DECR_PC_AFTER_BREAK, rpid);
|
||
if (linuxthreads_step_pid == rpid)
|
||
{
|
||
child_resume (rpid, 1, linuxthreads_step_signo);
|
||
}
|
||
else
|
||
{
|
||
child_resume (rpid, 0, TARGET_SIGNAL_0);
|
||
}
|
||
continue;
|
||
}
|
||
}
|
||
|
||
/* Walk through linuxthreads array in order to stop them */
|
||
if (linuxthreads_breakpoints_inserted)
|
||
update_stop_threads (rpid);
|
||
|
||
}
|
||
else if (rpid != inferior_pid)
|
||
continue;
|
||
|
||
store_waitstatus (ourstatus, status);
|
||
|
||
if (linuxthreads_attach_pending && !stop_soon_quietly)
|
||
{
|
||
int on = 1;
|
||
if (!using_thread_db)
|
||
{
|
||
target_write_memory (linuxthreads_debug,
|
||
(char *) &on, sizeof (on));
|
||
update_stop_threads (rpid);
|
||
}
|
||
linuxthreads_attach_pending = 0;
|
||
}
|
||
|
||
if (linuxthreads_breakpoints_inserted
|
||
&& WIFSTOPPED(status)
|
||
&& WSTOPSIG(status) == SIGTRAP)
|
||
linuxthreads_breakpoint_pid = rpid;
|
||
else if (linuxthreads_breakpoint_pid)
|
||
linuxthreads_breakpoint_pid = 0;
|
||
|
||
return rpid;
|
||
}
|
||
}
|
||
|
||
/* Fork an inferior process, and start debugging it with ptrace. */
|
||
|
||
static void
|
||
linuxthreads_create_inferior (char *exec_file, char *allargs, char **env)
|
||
{
|
||
if (!exec_file && !exec_bfd)
|
||
{
|
||
error ("No executable file specified.\n\
|
||
Use the \"file\" or \"exec-file\" command.");
|
||
return;
|
||
}
|
||
|
||
push_target (&linuxthreads_ops);
|
||
linuxthreads_breakpoints_inserted = 1;
|
||
linuxthreads_breakpoint_last = -1;
|
||
linuxthreads_wait_last = -1;
|
||
WSETSTOP (linuxthreads_exit_status, 0);
|
||
|
||
if (linuxthreads_max)
|
||
linuxthreads_attach_pending = 1;
|
||
|
||
child_ops.to_create_inferior (exec_file, allargs, env);
|
||
}
|
||
|
||
void
|
||
linuxthreads_discard_global_state (void)
|
||
{
|
||
linuxthreads_inferior_pid = 0;
|
||
linuxthreads_breakpoint_pid = 0;
|
||
linuxthreads_step_pid = 0;
|
||
linuxthreads_step_signo = TARGET_SIGNAL_0;
|
||
linuxthreads_manager_pid = 0;
|
||
linuxthreads_initial_pid = 0;
|
||
linuxthreads_attach_pending = 0;
|
||
linuxthreads_max = 0;
|
||
}
|
||
|
||
/* Clean up after the inferior dies. */
|
||
|
||
static void
|
||
linuxthreads_mourn_inferior (void)
|
||
{
|
||
if (linuxthreads_max)
|
||
{
|
||
int off = 0;
|
||
target_write_memory (linuxthreads_debug, (char *)&off, sizeof (off));
|
||
|
||
linuxthreads_discard_global_state ();
|
||
init_thread_list(); /* Destroy thread info */
|
||
}
|
||
|
||
child_ops.to_mourn_inferior ();
|
||
|
||
unpush_target (&linuxthreads_ops);
|
||
}
|
||
|
||
/* Kill the inferior process */
|
||
|
||
static void
|
||
linuxthreads_kill (void)
|
||
{
|
||
int rpid;
|
||
int status;
|
||
|
||
if (inferior_pid == 0)
|
||
return;
|
||
|
||
if (linuxthreads_max && linuxthreads_manager_pid != 0)
|
||
{
|
||
/* Remove all threads status. */
|
||
inferior_pid = linuxthreads_manager_pid;
|
||
iterate_active_threads (kill_thread, 1);
|
||
}
|
||
|
||
kill_thread (inferior_pid);
|
||
|
||
#if 0
|
||
/* doing_quit_force solves a real problem, but I think a properly
|
||
placed call to catch_errors would do the trick much more cleanly. */
|
||
if (doing_quit_force >= 0)
|
||
{
|
||
if (linuxthreads_max && linuxthreads_manager_pid != 0)
|
||
{
|
||
/* Wait for thread to complete */
|
||
while ((rpid = waitpid (-1, &status, __WCLONE)) > 0)
|
||
if (!WIFEXITED(status))
|
||
kill_thread (rpid);
|
||
|
||
while ((rpid = waitpid (-1, &status, 0)) > 0)
|
||
if (!WIFEXITED(status))
|
||
kill_thread (rpid);
|
||
}
|
||
else
|
||
while ((rpid = waitpid (inferior_pid, &status, 0)) > 0)
|
||
if (!WIFEXITED(status))
|
||
ptrace (PT_KILL, inferior_pid, (PTRACE_ARG3_TYPE) 0, 0);
|
||
}
|
||
#endif
|
||
|
||
/* Wait for all threads. */
|
||
do
|
||
{
|
||
rpid = waitpid (-1, &status, __WCLONE | WNOHANG);
|
||
}
|
||
while (rpid > 0 || errno == EINTR);
|
||
/* FIXME: should no longer need to handle EINTR here. */
|
||
|
||
do
|
||
{
|
||
rpid = waitpid (-1, &status, WNOHANG);
|
||
}
|
||
while (rpid > 0 || errno == EINTR);
|
||
/* FIXME: should no longer need to handle EINTR here. */
|
||
|
||
linuxthreads_mourn_inferior ();
|
||
}
|
||
|
||
/* Insert a breakpoint */
|
||
|
||
static int
|
||
linuxthreads_insert_breakpoint (CORE_ADDR addr, char *contents_cache)
|
||
{
|
||
if (linuxthreads_max && linuxthreads_manager_pid != 0)
|
||
{
|
||
linuxthreads_breakpoint_addr = addr;
|
||
iterate_active_threads (insert_breakpoint, 1);
|
||
insert_breakpoint (linuxthreads_manager_pid);
|
||
}
|
||
|
||
return child_ops.to_insert_breakpoint (addr, contents_cache);
|
||
}
|
||
|
||
/* Remove a breakpoint */
|
||
|
||
static int
|
||
linuxthreads_remove_breakpoint (CORE_ADDR addr, char *contents_cache)
|
||
{
|
||
if (linuxthreads_max && linuxthreads_manager_pid != 0)
|
||
{
|
||
linuxthreads_breakpoint_addr = addr;
|
||
iterate_active_threads (remove_breakpoint, 1);
|
||
remove_breakpoint (linuxthreads_manager_pid);
|
||
}
|
||
|
||
return child_ops.to_remove_breakpoint (addr, contents_cache);
|
||
}
|
||
|
||
/* Mark our target-struct as eligible for stray "run" and "attach" commands. */
|
||
|
||
static int
|
||
linuxthreads_can_run (void)
|
||
{
|
||
return child_suppress_run;
|
||
}
|
||
|
||
|
||
static void
|
||
init_linuxthreads_ops (void)
|
||
{
|
||
linuxthreads_ops.to_shortname = "linuxthreads";
|
||
linuxthreads_ops.to_longname = "LINUX threads and pthread.";
|
||
linuxthreads_ops.to_doc = "LINUX threads and pthread support.";
|
||
linuxthreads_ops.to_attach = linuxthreads_attach;
|
||
linuxthreads_ops.to_detach = linuxthreads_detach;
|
||
linuxthreads_ops.to_resume = linuxthreads_resume;
|
||
linuxthreads_ops.to_wait = linuxthreads_wait;
|
||
linuxthreads_ops.to_kill = linuxthreads_kill;
|
||
linuxthreads_ops.to_can_run = linuxthreads_can_run;
|
||
linuxthreads_ops.to_stratum = thread_stratum;
|
||
linuxthreads_ops.to_insert_breakpoint = linuxthreads_insert_breakpoint;
|
||
linuxthreads_ops.to_remove_breakpoint = linuxthreads_remove_breakpoint;
|
||
linuxthreads_ops.to_create_inferior = linuxthreads_create_inferior;
|
||
linuxthreads_ops.to_mourn_inferior = linuxthreads_mourn_inferior;
|
||
linuxthreads_ops.to_thread_alive = linuxthreads_thread_alive;
|
||
linuxthreads_ops.to_pid_to_str = linuxthreads_pid_to_str;
|
||
linuxthreads_ops.to_magic = OPS_MAGIC;
|
||
}
|
||
|
||
void
|
||
_initialize_linuxthreads (void)
|
||
{
|
||
struct sigaction sact;
|
||
sigset_t linuxthreads_wait_mask; /* sigset with SIGCHLD */
|
||
|
||
init_linuxthreads_ops ();
|
||
add_target (&linuxthreads_ops);
|
||
child_suppress_run = 1;
|
||
|
||
/* Hook onto the "new_objfile" event.
|
||
* If someone else is already hooked onto the event,
|
||
* then make sure he will be called after we are.
|
||
*/
|
||
target_new_objfile_chain = target_new_objfile_hook;
|
||
target_new_objfile_hook = linuxthreads_new_objfile;
|
||
|
||
/* Attach SIGCHLD handler */
|
||
sact.sa_handler = sigchld_handler;
|
||
sigemptyset (&sact.sa_mask);
|
||
sact.sa_flags = 0;
|
||
sigaction (SIGCHLD, &sact, NULL);
|
||
|
||
/* initialize SIGCHLD mask */
|
||
sigemptyset (&linuxthreads_wait_mask);
|
||
sigaddset (&linuxthreads_wait_mask, SIGCHLD);
|
||
|
||
/* Use SIG_BLOCK to block receipt of SIGCHLD.
|
||
The block_mask will allow us to wait for this signal explicitly. */
|
||
sigprocmask(SIG_BLOCK,
|
||
&linuxthreads_wait_mask,
|
||
&linuxthreads_block_mask);
|
||
/* Make sure that linuxthreads_block_mask is not blocking SIGCHLD */
|
||
sigdelset (&linuxthreads_block_mask, SIGCHLD);
|
||
}
|