--- /dev/null
+/* Low level interface for debugging UnixWare user-mode threads for
+ GDB, the GNU debugger.
+
+ Copyright 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. */
+
+
+/* Like many systems, UnixWare implements two classes of threads:
+ kernel-mode threads, which are scheduled by the kernel; and
+ user-mode threads, which are scheduled by a library. UnixWare
+ calls these two classes lightweight processes (LWPs) and threads,
+ respectively.
+
+ This module deals with user-mode threads. It calls procfs_ops
+ functions to deal with LWPs and processes and core_ops functions to
+ deal with core files.
+
+ As of this writing, the user-mode thread debugging interface is not
+ documented beyond the comments in <thread.h>. The following
+ description has been gleaned from experience and from information
+ provided by SCO.
+
+ libthread.so, against which all UnixWare user-mode thread programs
+ link, provides a global thread_debug structure named _thr_debug.
+ It has three fields:
+
+ (1) thr_map is a pointer to a pointer to an element of a
+ thread_map ring. A thread_map contains a single thread's id
+ number, state, LWP pointer, recent register state, and other
+ useful information.
+
+ (2) thr_brk is a pointer to a stub function that libthread.so
+ calls when it changes a thread's state, e.g. by creating it,
+ switching it to an LWP, or causing it to exit.
+
+ (3) thr_debug_on controls whether libthread.so calls thr_brk().
+
+ Debuggers are able to track thread activity by setting a private
+ breakpoint on thr_brk() and setting thr_debug_on to 1.
+
+ thr_brk() receives two arguments:
+
+ (1) a pointer to a thread_map describing the thread being
+ changed; and
+
+ (2) an enum thread_change specifying one of the following
+ changes:
+
+ invalid unknown
+ thread_create thread has just been created
+ thread_exit thread has just exited
+ switch_begin thread will be switched to an LWP
+ switch_complete thread has been switched to an LWP
+ cancel_complete thread wasn't switched to an LWP
+ thread_suspend thread has been thr_suspend()ed
+ thread_suspend_pending thread will be thr_suspend()ed
+ thread_continue thread has been thr_continue()d
+
+ The thread_map argument to thr_brk() is NULL under the following
+ circumstances:
+
+ - The main thread is being acted upon. The main thread always
+ has id 1, so its thread_map is easy to find by scanning through
+ _thr_debug.thr_map.
+
+ - A "switch_complete" change is occurring, which means that the
+ thread specified in the most recent "switch_begin" change has
+ moved to an LWP.
+
+ - A "cancel_complete" change is occurring, which means that the
+ thread specified in the most recent "switch_begin" change has
+ not moved to an LWP after all.
+
+ - A spurious "switch_begin" change is occurring after a
+ "thread_exit" change.
+
+ Between switch_begin and switch_complete or cancel_complete, the
+ affected thread's LWP pointer is not reliable. It is possible that
+ other parts of the thread's thread_map are also unreliable during
+ that time. */
+
+
+#include "defs.h"
+#include "gdbthread.h"
+#include "target.h"
+#include "inferior.h"
+#include <fcntl.h>
+
+/*
+ * <thread.h> includes <sys/priocntl.h>, which requires boolean_t from
+ * <sys/types.h>, which doesn't typedef boolean_t with gcc.
+ */
+#define boolean_t int
+#include <thread.h>
+#undef boolean_t
+
+#include <synch.h> /* for UnixWare 2.x */
+
+
+/*
+ * Whether to emit debugging output.
+ */
+#define DEBUG 0
+
+/*
+ * Default debugging output file, overridden by envvar UWTHR_DEBUG.
+ */
+#define DEBUG_FILE "/dev/tty"
+
+/*
+ * #if DEBUG, write string S to the debugging output channel.
+ */
+#if !DEBUG
+# define DBG(fmt_and_args)
+# define DBG2(fmt_and_args)
+#else
+# define DBG(fmt_and_args) dbg fmt_and_args
+# define DBG2(fmt_and_args)
+#endif
+
+/*
+ * Back end to CALL_BASE() and TRY_BASE(): evaluate CALL, then convert
+ * inferior_pid to a composite thread/process id.
+ */
+#define CALL_BASE_1(call) \
+do { \
+ DBG2(("CALL_BASE(" #call ")")); \
+ call; \
+ do_cleanups (infpid_cleanup); \
+} while (0)
+
+/*
+ * If inferior_pid can be converted to a composite lwp/process id, do so,
+ * evaluate base_ops function CALL, and then convert inferior_pid back to a
+ * composite thread/process id.
+ *
+ * Otherwise, issue an error message and return nonlocally.
+ */
+#define CALL_BASE(call) \
+do { \
+ if (!lwp_infpid ()) \
+ error ("uw-thread: "__FUNCTION__": no lwp"); \
+ CALL_BASE_1 (call); \
+} while (0)
+
+/*
+ * Like CALL_BASE(), but instead of returning nonlocally on error, set
+ * *CALLED to whether the inferior_pid conversion was successful.
+ */
+#define TRY_BASE(call, called) \
+do { \
+ if ((*(called) = lwp_infpid ())) \
+ CALL_BASE_1 (call); \
+} while (0)
+
+/*
+ * Information passed by thread_iter() to its callback parameter.
+ */
+typedef struct {
+ struct thread_map map;
+ __lwp_desc_t lwp;
+ CORE_ADDR mapp;
+} iter_t;
+
+/*
+ * Private thread data for the thread_info struct.
+ */
+struct private_thread_info {
+ int stable; /* 0 if libthread.so is modifying thread map */
+ int thrid; /* thread id assigned by libthread.so */
+ int lwpid; /* thread's lwp if .stable, 0 means no lwp */
+ CORE_ADDR mapp; /* address of thread's map structure */
+};
+
+
+/* procfs.c's target-specific operations. */
+extern struct target_ops procfs_ops;
+
+/* Flag to prevent procfs.c from starting inferior processes. */
+extern int procfs_suppress_run;
+
+/* This module's target-specific operations. */
+static struct target_ops uw_thread_ops;
+
+/* Copy of the target over which uw_thread_ops is pushed. This is
+ more convenient than a pointer to procfs_ops or core_ops, because
+ they lack current_target's default callbacks. */
+static struct target_ops base_ops;
+
+/* Saved pointer to previous owner of target_new_objfile_hook. */
+static void (*target_new_objfile_chain)(struct objfile *);
+
+/* Whether we are debugging a user-space thread program. This isn't
+ set until after libthread.so is loaded by the program being
+ debugged.
+
+ Except for module one-time intialization and where otherwise
+ documented, no functions in this module get called when
+ !uw_thread_active. */
+static int uw_thread_active;
+
+/* For efficiency, cache the addresses of libthread.so's _thr_debug
+ structure, its thr_brk stub function, and the main thread's map. */
+static CORE_ADDR thr_debug_addr;
+static CORE_ADDR thr_brk_addr;
+static CORE_ADDR thr_map_main;
+
+/* Remember the thread most recently marked as switching. Necessary because
+ libthread.so passes null map when calling stub with tc_*_complete. */
+static struct thread_info *switchto_thread;
+
+/* Cleanup chain for safely restoring inferior_pid after CALL_BASE. */
+static struct cleanup *infpid_cleanup;
+
+
+#if DEBUG
+/*
+ * Helper function for DBG() macro: if printf-style FMT is non-null, format it
+ * with args and display the result on the debugging output channel.
+ */
+static void
+dbg (char *fmt, ...)
+{
+ static int fd = -1, len;
+ va_list args;
+ char buf[1024];
+ char *path;
+
+ if (!fmt)
+ return;
+
+ if (fd < 0)
+ {
+ path = getenv ("UWTHR_DEBUG");
+ if (!path)
+ path = DEBUG_FILE;
+ if ((fd = open (path, O_WRONLY | O_CREAT | O_TRUNC, 0664)) < 0)
+ error ("can't open %s\n", path);
+ }
+
+ va_start (args, fmt);
+ vsprintf (buf, fmt, args);
+ va_end (args);
+
+ len = strlen (buf);
+ buf[len] = '\n';
+ (void)write (fd, buf, len + 1);
+}
+
+#if 0
+/*
+ * Return a string representing composite PID's components.
+ */
+static char *
+dbgpid (int pid)
+{
+ static char *buf, buf1[80], buf2[80];
+ if (!buf || buf == buf2)
+ buf = buf1;
+ else
+ buf = buf2;
+
+ if (pid <= 0)
+ sprintf (buf, "%d", pid);
+ else
+ sprintf (buf, "%s %d/%d", ISTID (pid) ? "thr" : "lwp",
+ TIDGET (pid), PIDGET (pid));
+
+ return buf;
+}
+
+/*
+ * Return a string representing thread state CHANGE.
+ */
+static char *
+dbgchange (enum thread_change change)
+{
+ switch (change) {
+ case tc_invalid: return "invalid";
+ case tc_thread_create: return "thread_create";
+ case tc_thread_exit: return "thread_exit";
+ case tc_switch_begin: return "switch_begin";
+ case tc_switch_complete: return "switch_complete";
+ case tc_cancel_complete: return "cancel_complete";
+ case tc_thread_suspend: return "thread_suspend";
+ case tc_thread_suspend_pending: return "thread_suspend_pending";
+ case tc_thread_continue: return "thread_continue";
+ default: return "unknown";
+ }
+}
+
+/*
+ * Return a string representing thread STATE.
+ */
+static char *
+dbgstate (int state)
+{
+ switch (state) {
+ case TS_ONPROC: return "running";
+ case TS_SLEEP: return "sleeping";
+ case TS_RUNNABLE: return "runnable";
+ case TS_ZOMBIE: return "zombie";
+ case TS_SUSPENDED: return "suspended";
+#ifdef TS_FORK
+ case TS_FORK: return "forking";
+#endif
+ default: return "confused";
+ }
+}
+#endif /* 0 */
+#endif /* DEBUG */
+
+
+/*
+ * Read the contents of _thr_debug into *DEBUGP. Return success.
+ */
+static int
+read_thr_debug (struct thread_debug *debugp)
+{
+ return base_ops.to_xfer_memory (thr_debug_addr, (char *)debugp,
+ sizeof (*debugp), 0, &base_ops);
+}
+
+/*
+ * Read into MAP the contents of the thread map at inferior process address
+ * MAPP. Return success.
+ */
+static int
+read_map (CORE_ADDR mapp, struct thread_map *map)
+{
+ return base_ops.to_xfer_memory ((CORE_ADDR)THR_MAP (mapp), (char *)map,
+ sizeof (*map), 0, &base_ops);
+}
+
+/*
+ * Read into LWP the contents of the lwp decriptor at inferior process address
+ * LWPP. Return success.
+ */
+static int
+read_lwp (CORE_ADDR lwpp, __lwp_desc_t *lwp)
+{
+ return base_ops.to_xfer_memory (lwpp, (char *)lwp,
+ sizeof (*lwp), 0, &base_ops);
+}
+
+/*
+ * Iterate through all user threads, applying FUNC(<map>, <lwp>, DATA) until
+ * (a) FUNC returns nonzero,
+ * (b) FUNC has been applied to all threads, or
+ * (c) an error occurs,
+ * where <map> is the thread's struct thread_map and <lwp> if non-null is the
+ * thread's current __lwp_desc_t.
+ *
+ * If a call to FUNC returns nonzero, return that value; otherwise, return 0.
+ */
+static int
+thread_iter (int (*func)(iter_t *, void *), void *data)
+{
+ struct thread_debug debug;
+ CORE_ADDR first, mapp;
+ iter_t iter;
+ int ret;
+
+ if (!read_thr_debug (&debug))
+ return 0;
+ if (!base_ops.to_xfer_memory ((CORE_ADDR)debug.thr_map, (char *)&mapp,
+ sizeof (mapp), 0, &base_ops))
+ return 0;
+ if (!mapp)
+ return 0;
+
+ for (first = mapp;;)
+ {
+ if (!read_map (mapp, &iter.map))
+ return 0;
+
+ if (iter.map.thr_lwpp)
+ if (!read_lwp ((CORE_ADDR)iter.map.thr_lwpp, &iter.lwp))
+ return 0;
+
+ iter.mapp = mapp;
+ if ((ret = func (&iter, data)))
+ return ret;
+
+ mapp = (CORE_ADDR)iter.map.thr_next;
+ if (mapp == first)
+ return 0;
+ }
+}
+
+/*
+ * Deactivate user-mode thread support.
+ */
+static void
+deactivate_uw_thread (void)
+{
+ uw_thread_active = 0;
+ unpush_target (&uw_thread_ops);
+}
+
+/*
+ * Return the composite lwp/process id corresponding to composite
+ * id PID. If PID is a thread with no lwp, return 0.
+ */
+static int
+thr_to_lwp (int pid)
+{
+ struct thread_info *info;
+ int lid;
+
+ if (!ISTID (pid))
+ lid = pid;
+ else if (!(info = find_thread_pid (pid)))
+ lid = 0;
+ else if (!info->private->lwpid)
+ lid = 0;
+ else
+ lid = MKLID (pid, info->private->lwpid);
+
+ DBG2((" thr_to_lwp(%s) = %s", dbgpid (pid), dbgpid (lid)));
+ return lid;
+}
+
+/*
+ * find_thread_lwp() callback: return whether TP describes a thread
+ * associated with lwp id DATA.
+ */
+static int
+find_thread_lwp_callback (struct thread_info *tp, void *data)
+{
+ int lwpid = (int)data;
+
+ if (!ISTID (tp->pid))
+ return 0;
+ if (!tp->private->stable)
+ return 0;
+ if (lwpid != tp->private->lwpid)
+ return 0;
+
+ /* match */
+ return 1;
+}
+
+/*
+ * If a thread is associated with lwp id LWPID, return the corresponding
+ * member of the global thread list; otherwise, return null.
+ */
+static struct thread_info *
+find_thread_lwp (int lwpid)
+{
+ return iterate_over_threads (find_thread_lwp_callback, (void *)lwpid);
+}
+
+/*
+ * Return the composite thread/process id corresponding to composite
+ * id PID. If PID is an lwp with no thread, return PID.
+ */
+static int
+lwp_to_thr (int pid)
+{
+ struct thread_info *info;
+ int tid = pid, lwpid;
+
+ if (ISTID (pid))
+ goto done;
+ if (!(lwpid = LIDGET (pid)))
+ goto done;
+ if (!(info = find_thread_lwp (lwpid)))
+ goto done;
+ tid = MKTID (pid, info->private->thrid);
+
+ done:
+ DBG2((ISTID (tid) ? NULL : "lwp_to_thr: no thr for %s", dbgpid (pid)));
+ return tid;
+}
+
+/*
+ * do_cleanups() callback: convert inferior_pid to a composite
+ * thread/process id after having made a procfs call.
+ */
+static void
+thr_infpid (void *unused)
+{
+ int pid = lwp_to_thr (inferior_pid);
+ DBG2((" inferior_pid from procfs: %s => %s",
+ dbgpid (inferior_pid), dbgpid (pid)));
+ inferior_pid = pid;
+}
+
+/*
+ * If possible, convert inferior_pid to a composite lwp/process id in
+ * preparation for making a procfs call. Return success.
+ */
+static int
+lwp_infpid (void)
+{
+ int pid = thr_to_lwp (inferior_pid);
+ DBG2((" inferior_pid to procfs: %s => %s",
+ dbgpid (inferior_pid), dbgpid (pid)));
+
+ if (!pid)
+ return 0;
+
+ inferior_pid = pid;
+ infpid_cleanup = make_cleanup (thr_infpid, NULL);
+ return 1;
+}
+
+/*
+ * Add to the global thread list a new user-mode thread with system id THRID,
+ * lwp id LWPID, map address MAPP, and composite thread/process PID.
+ */
+static void
+add_thread_uw (int thrid, int lwpid, CORE_ADDR mapp, int pid)
+{
+ struct thread_info *newthread;
+
+ if ((newthread = add_thread (pid)) == NULL)
+ error ("failed to create new thread structure");
+
+ newthread->private = xmalloc (sizeof (struct private_thread_info));
+ newthread->private->stable = 1;
+ newthread->private->thrid = thrid;
+ newthread->private->lwpid = lwpid;
+ newthread->private->mapp = mapp;
+
+ if (target_has_execution)
+ printf_unfiltered ("[New %s]\n", target_pid_to_str (pid));
+}
+
+/*
+ * notice_threads() and find_main() callback: if the thread list doesn't
+ * already contain the thread described by ITER, add it if it's the main
+ * thread or if !DATA.
+ */
+static int
+notice_thread (iter_t *iter, void *data)
+{
+ int thrid = iter->map.thr_tid;
+ int lwpid = !iter->map.thr_lwpp ? 0 : iter->lwp.lwp_id;
+ int pid = MKTID (inferior_pid, thrid);
+
+ if (!find_thread_pid (pid) && (!data || thrid == 1))
+ add_thread_uw (thrid, lwpid, iter->mapp, pid);
+
+ return 0;
+}
+
+/*
+ * Add to the thread list any threads it doesn't already contain.
+ */
+static void
+notice_threads (void)
+{
+ thread_iter (notice_thread, NULL);
+}
+
+/*
+ * Return the address of the main thread's map. On error, return 0.
+ */
+static CORE_ADDR
+find_main (void)
+{
+ if (!thr_map_main)
+ {
+ struct thread_info *info;
+ thread_iter (notice_thread, (void *)1);
+ if ((info = find_thread_pid (MKTID (inferior_pid, 1))))
+ thr_map_main = info->private->mapp;
+ }
+ return thr_map_main;
+}
+
+/*
+ * Attach to process specified by ARGS, then initialize for debugging it
+ * and wait for the trace-trap that results from attaching.
+ *
+ * This function only gets called with uw_thread_active == 0.
+ */
+static void
+uw_thread_attach (char *args, int from_tty)
+{
+ procfs_ops.to_attach (args, from_tty);
+ if (uw_thread_active)
+ thr_infpid (NULL);
+}
+
+/*
+ * Detach from the process attached to by uw_thread_attach().
+ */
+static void
+uw_thread_detach (char *args, int from_tty)
+{
+ deactivate_uw_thread ();
+ base_ops.to_detach (args, from_tty);
+}
+
+/*
+ * Tell the inferior process to continue running thread PID if >= 0
+ * and all threads otherwise.
+ */
+static void
+uw_thread_resume (int pid, int step, enum target_signal signo)
+{
+ if (pid > 0 && !(pid = thr_to_lwp (pid)))
+ pid = -1;
+
+ CALL_BASE (base_ops.to_resume (pid, step, signo));
+}
+
+/*
+ * If the trap we just received from lwp PID was due to a breakpoint
+ * on the libthread.so debugging stub, update this module's state
+ * accordingly.
+ */
+static void
+libthread_stub (int pid)
+{
+ CORE_ADDR sp, mapp, mapp_main;
+ enum thread_change change;
+ struct thread_map map;
+ __lwp_desc_t lwp;
+ int tid = 0, lwpid;
+ struct thread_info *info;
+
+ /* Check for stub breakpoint. */
+ if (read_pc_pid (pid) - DECR_PC_AFTER_BREAK != thr_brk_addr)
+ return;
+
+ /* Retrieve stub args. */
+ sp = read_register_pid (SP_REGNUM, pid);
+ if (!base_ops.to_xfer_memory (sp + SP_ARG0, (char *)&mapp,
+ sizeof (mapp), 0, &base_ops))
+ goto err;
+ if (!base_ops.to_xfer_memory (sp + SP_ARG0 + sizeof (mapp), (char *)&change,
+ sizeof (change), 0, &base_ops))
+ goto err;
+
+ /* create_inferior() may not have finished yet, so notice the main
+ thread to ensure that it's displayed first by add_thread(). */
+ mapp_main = find_main ();
+
+ /* Notice thread creation, deletion, or stability change. */
+ switch (change) {
+ case tc_switch_begin:
+ if (!mapp) /* usually means main thread */
+ mapp = mapp_main;
+ /* fall through */
+
+ case tc_thread_create:
+ case tc_thread_exit:
+ if (!mapp)
+ break;
+ if (!read_map (mapp, &map))
+ goto err;
+ tid = MKTID (pid, map.thr_tid);
+
+ switch (change) {
+ case tc_thread_create: /* new thread */
+ if (!map.thr_lwpp)
+ lwpid = 0;
+ else if (!read_lwp ((CORE_ADDR)map.thr_lwpp, &lwp))
+ goto err;
+ else
+ lwpid = lwp.lwp_id;
+ add_thread_uw (map.thr_tid, lwpid, mapp, tid);
+ break;
+
+ case tc_thread_exit: /* thread has exited */
+ printf_unfiltered ("[Exited %s]\n", target_pid_to_str (tid));
+ delete_thread (tid);
+ if (tid == inferior_pid)
+ inferior_pid = pid;
+ break;
+
+ case tc_switch_begin: /* lwp is switching threads */
+ if (switchto_thread)
+ goto err;
+ if (!(switchto_thread = find_thread_pid (tid)))
+ goto err;
+ switchto_thread->private->stable = 0;
+ break;
+
+ default:
+ break;
+ }
+ break;
+
+ case tc_switch_complete: /* lwp has switched threads */
+ case tc_cancel_complete: /* lwp didn't switch threads */
+ if (!switchto_thread)
+ goto err;
+
+ if (change == tc_switch_complete)
+ {
+ /*
+ * If switchto_thread is the main thread, then (a) the corresponding
+ * tc_switch_begin probably received a null map argument and therefore
+ * (b) it may have been a spurious switch following a tc_thread_exit.
+ *
+ * Therefore, explicitly query the thread's lwp before caching it in
+ * its thread list entry.
+ */
+ if (!read_map (switchto_thread->private->mapp, &map))
+ goto err;
+ if (map.thr_lwpp)
+ {
+ if (!read_lwp ((CORE_ADDR)map.thr_lwpp, &lwp))
+ goto err;
+ if ((info = find_thread_lwp (lwp.lwp_id)))
+ info->private->lwpid = 0;
+ switchto_thread->private->lwpid = lwp.lwp_id;
+ }
+ }
+
+ switchto_thread->private->stable = 1;
+ switchto_thread = NULL;
+ break;
+
+ case tc_invalid:
+ case tc_thread_suspend:
+ case tc_thread_suspend_pending:
+ case tc_thread_continue:
+ err:
+ DBG(("unexpected condition in libthread_stub()"));
+ break;
+ }
+
+ DBG2(("libthread_stub(%s): %s %s %s", dbgpid (pid), dbgpid (tid),
+ dbgchange (change), tid ? dbgstate (map.thr_state) : ""));
+}
+
+/*
+ * Wait for thread/lwp/process ID if >= 0 or for any thread otherwise.
+ */
+static int
+uw_thread_wait (int pid, struct target_waitstatus *status)
+{
+ if (pid > 0)
+ pid = thr_to_lwp (pid);
+ CALL_BASE (pid = base_ops.to_wait (pid > 0 ? pid : -1, status));
+
+ if (status->kind == TARGET_WAITKIND_STOPPED &&
+ status->value.sig == TARGET_SIGNAL_TRAP)
+ libthread_stub (pid);
+
+ return lwp_to_thr (pid);
+}
+
+/*
+ * Tell gdb about the registers in the thread/lwp/process specified by
+ * inferior_pid.
+ */
+static void
+uw_thread_fetch_registers (int regno)
+{
+ int called;
+ struct thread_info *info;
+ struct thread_map map;
+
+ TRY_BASE (base_ops.to_fetch_registers (regno), &called);
+ if (called)
+ return;
+
+ if (!(info = find_thread_pid (inferior_pid)))
+ return;
+ if (!read_map (info->private->mapp, &map))
+ return;
+
+ supply_gregset (&map.thr_ucontext.uc_mcontext.gregs);
+ supply_fpregset (&map.thr_ucontext.uc_mcontext.fpregs);
+}
+
+/*
+ * Store gdb's current view of the register set into the thread/lwp/process
+ * specified by inferior_pid.
+ */
+static void
+uw_thread_store_registers (int regno)
+{
+ CALL_BASE (base_ops.to_store_registers (regno));
+}
+
+/*
+ * Prepare to modify the registers array.
+ */
+static void
+uw_thread_prepare_to_store (void)
+{
+ CALL_BASE (base_ops.to_prepare_to_store ());
+}
+
+/*
+ * Fork an inferior process and start debugging it.
+ *
+ * This function only gets called with uw_thread_active == 0.
+ */
+static void
+uw_thread_create_inferior (char *exec_file, char *allargs, char **env)
+{
+ if (uw_thread_active)
+ deactivate_uw_thread ();
+
+ procfs_ops.to_create_inferior (exec_file, allargs, env);
+ if (uw_thread_active)
+ {
+ find_main ();
+ thr_infpid (NULL);
+ }
+}
+
+/*
+ * Kill and forget about the inferior process.
+ */
+static void
+uw_thread_kill (void)
+{
+ base_ops.to_kill ();
+}
+
+/*
+ * Clean up after the inferior exits.
+ */
+static void
+uw_thread_mourn_inferior (void)
+{
+ remove_thread_event_breakpoints ();
+ deactivate_uw_thread ();
+ base_ops.to_mourn_inferior ();
+}
+
+/*
+ * Return whether this module can attach to and run processes.
+ *
+ * This function only gets called with uw_thread_active == 0.
+ */
+static int
+uw_thread_can_run (void)
+{
+ return procfs_suppress_run;
+}
+
+/*
+ * Return whether thread PID is still valid.
+ */
+static int
+uw_thread_alive (int pid)
+{
+ if (!ISTID (pid))
+ return base_ops.to_thread_alive (pid);
+
+ /* If it's in the thread list, it's valid, because otherwise
+ libthread_stub() would have deleted it. */
+ return in_thread_list (pid);
+}
+
+/*
+ * Add to the thread list any threads and lwps it doesn't already contain.
+ */
+static void
+uw_thread_find_new_threads (void)
+{
+ CALL_BASE (if (base_ops.to_find_new_threads)
+ base_ops.to_find_new_threads ());
+ notice_threads ();
+}
+
+/*
+ * Return a string for pretty-printing PID in "info threads" output.
+ * This may be called by either procfs.c or by generic gdb.
+ */
+static char *
+uw_thread_pid_to_str (int pid)
+{
+#define FMT "Thread %d"
+ static char buf[sizeof (FMT) + 3 * sizeof (pid)];
+
+ if (!ISTID (pid))
+ /* core_ops says "process foo", so call procfs_ops explicitly. */
+ return procfs_ops.to_pid_to_str (pid);
+
+ sprintf (buf, FMT, TIDGET (pid));
+#undef FMT
+ return buf;
+}
+
+/*
+ * Return a string displaying INFO state information in "info threads"
+ * output.
+ */
+static char *
+uw_extra_thread_info (struct thread_info *info)
+{
+ static char buf[80];
+ struct thread_map map;
+ __lwp_desc_t lwp;
+ int lwpid;
+ char *name;
+
+ if (!ISTID (info->pid))
+ return NULL;
+
+ if (!info->private->stable)
+ return "switching";
+
+ if (!read_map (info->private->mapp, &map))
+ return NULL;
+
+ if (!map.thr_lwpp || !read_lwp ((CORE_ADDR)map.thr_lwpp, &lwp))
+ lwpid = 0;
+ else
+ lwpid = lwp.lwp_id;
+
+ switch (map.thr_state) {
+ case TS_ONPROC: name = "running"; break;
+ case TS_SLEEP: name = "sleeping"; break;
+ case TS_RUNNABLE: name = "runnable"; break;
+ case TS_ZOMBIE: name = "zombie"; break;
+ case TS_SUSPENDED: name = "suspended"; break;
+#ifdef TS_FORK
+ case TS_FORK: name = "forking"; break;
+#endif
+ default: name = "confused"; break;
+ }
+
+ if (!lwpid)
+ return name;
+
+ sprintf (buf, "%s, LWP %d", name, lwpid);
+ return buf;
+}
+
+/*
+ * Check whether libthread.so has just been loaded, and if so, try to
+ * initialize user-space thread debugging support.
+ *
+ * libthread.so loading happens while (a) an inferior process is being
+ * started by procfs and (b) a core image is being loaded.
+ *
+ * This function often gets called with uw_thread_active == 0.
+ */
+static void
+libthread_init (void)
+{
+ struct minimal_symbol *ms;
+ struct thread_debug debug;
+ CORE_ADDR onp;
+ struct breakpoint *b;
+ int one = 1;
+
+ /* Don't initialize twice. */
+ if (uw_thread_active)
+ return;
+
+ /* Check whether libthread.so has been loaded. */
+ if (!(ms = lookup_minimal_symbol ("_thr_debug", NULL, NULL)))
+ return;
+
+ /* Cache _thr_debug's address. */
+ if (!(thr_debug_addr = SYMBOL_VALUE_ADDRESS (ms)))
+ return;
+
+ /* Initialize base_ops.to_xfer_memory(). */
+ base_ops = current_target;
+
+ /* Load _thr_debug's current contents. */
+ if (!read_thr_debug (&debug))
+ return;
+
+ /* User code (e.g. my test programs) may dereference _thr_debug,
+ making it availble to GDB before shared libs are loaded. */
+ if (!debug.thr_map)
+ return;
+
+ /* libthread.so has been loaded, and the current_target should now
+ reflect core_ops or procfs_ops. */
+ push_target (&uw_thread_ops); /* must precede notice_threads() */
+ uw_thread_active = 1;
+
+ if (!target_has_execution)
+
+ /* Locate threads in core file. */
+ notice_threads ();
+
+ else
+ {
+ /* Set a breakpoint on the stub function provided by libthread.so. */
+ thr_brk_addr = (CORE_ADDR)debug.thr_brk;
+ if (!(b = create_thread_event_breakpoint (thr_brk_addr)))
+ goto err;
+
+ /* Activate the stub function. */
+ onp = (CORE_ADDR)&((struct thread_debug *)thr_debug_addr)->thr_debug_on;
+ if (!base_ops.to_xfer_memory ((CORE_ADDR)onp, (char *)&one,
+ sizeof (one), 1, &base_ops))
+ {
+ delete_breakpoint (b);
+ goto err;
+ }
+
+ /* Prepare for finding the main thread, which doesn't yet exist. */
+ thr_map_main = 0;
+ }
+
+ return;
+
+ err:
+ warning ("uw-thread: unable to initialize user-mode thread debugging\n");
+ deactivate_uw_thread ();
+}
+
+/*
+ * target_new_objfile_hook callback.
+ *
+ * If OBJFILE is non-null, check whether libthread.so was just loaded,
+ * and if so, prepare for user-mode thread debugging.
+ *
+ * If OBJFILE is null, libthread.so has gone away, so stop debugging
+ * user-mode threads.
+ *
+ * This function often gets called with uw_thread_active == 0.
+ */
+static void
+uw_thread_new_objfile (struct objfile *objfile)
+{
+ if (objfile)
+ libthread_init ();
+
+ else if (uw_thread_active)
+ deactivate_uw_thread ();
+
+ if (target_new_objfile_chain)
+ target_new_objfile_chain (objfile);
+}
+
+/*
+ * Initialize uw_thread_ops.
+ */
+static void
+init_uw_thread_ops (void)
+{
+ uw_thread_ops.to_shortname = "unixware-threads";
+ uw_thread_ops.to_longname = "UnixWare threads and pthread.";
+ uw_thread_ops.to_doc = "UnixWare threads and pthread support.";
+ uw_thread_ops.to_attach = uw_thread_attach;
+ uw_thread_ops.to_detach = uw_thread_detach;
+ uw_thread_ops.to_resume = uw_thread_resume;
+ uw_thread_ops.to_wait = uw_thread_wait;
+ uw_thread_ops.to_fetch_registers = uw_thread_fetch_registers;
+ uw_thread_ops.to_store_registers = uw_thread_store_registers;
+ uw_thread_ops.to_prepare_to_store = uw_thread_prepare_to_store;
+ uw_thread_ops.to_create_inferior = uw_thread_create_inferior;
+ uw_thread_ops.to_kill = uw_thread_kill;
+ uw_thread_ops.to_mourn_inferior = uw_thread_mourn_inferior;
+ uw_thread_ops.to_can_run = uw_thread_can_run;
+ uw_thread_ops.to_thread_alive = uw_thread_alive;
+ uw_thread_ops.to_find_new_threads = uw_thread_find_new_threads;
+ uw_thread_ops.to_pid_to_str = uw_thread_pid_to_str;
+ uw_thread_ops.to_extra_thread_info = uw_extra_thread_info;
+ uw_thread_ops.to_stratum = thread_stratum;
+ uw_thread_ops.to_magic = OPS_MAGIC;
+}
+
+/*
+ * Module startup initialization function, automagically called by
+ * init.c.
+ */
+void
+_initialize_uw_thread (void)
+{
+ init_uw_thread_ops ();
+ add_target (&uw_thread_ops);
+
+ procfs_suppress_run = 1;
+
+ /* Notice when libthread.so gets loaded. */
+ target_new_objfile_chain = target_new_objfile_hook;
+ target_new_objfile_hook = uw_thread_new_objfile;
+}
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