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Diffstat (limited to 'gdb/uw-thread.c')
| -rw-r--r-- | gdb/uw-thread.c | 1095 |
1 files changed, 1095 insertions, 0 deletions
diff --git a/gdb/uw-thread.c b/gdb/uw-thread.c new file mode 100644 index 00000000000..91d6638b7b8 --- /dev/null +++ b/gdb/uw-thread.c @@ -0,0 +1,1095 @@ +/* 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; +} |