Import initial work of libpthread debugging. This is a debugger independent

friend library for libpthread, the library will be used by debugger to
read/write libpthread's internal data structures.

6 files changed, 900 insertions, 0 deletions

diff --git a/lib/libpthread_dbg/Makefile b/lib/libpthread_dbg/Makefile
new file mode 100644
index 0000000..6114eb9
--- /dev/null
+++ b/lib/libpthread_dbg/Makefile
@@ -0,0 +1,20 @@
+# $FreeBSD$
+
+LIB=pthread_dbg
+SHLIB_MAJOR=1
+CFLAGS+=-DPTHREAD_KERNEL
+CFLAGS+=-I${.CURDIR}/../libc/include -I${.CURDIR}/../libpthread/thread \
+	-I${.CURDIR}/../../include
+CFLAGS+=-I${.CURDIR}/../libpthread/arch/${MACHINE_ARCH}/include
+CFLAGS+=-I${.CURDIR}/../libpthread/sys
+CFLAGS+=-I${.CURDIR} -I${.CURDIR}/arch/${MACHINE_ARCH}/include
+CFLAGS+=-Wall
+
+PRECIOUSLIB=yes
+
+.PATH: ${.CURDIR}
+
+SRCS+=pthread_dbg.c
+
+.include "${.CURDIR}/arch/${MACHINE_ARCH}/Makefile.inc"
+.include <bsd.lib.mk>
diff --git a/lib/libpthread_dbg/arch/i386/Makefile.inc b/lib/libpthread_dbg/arch/i386/Makefile.inc
new file mode 100644
index 0000000..794a4b0
--- /dev/null
+++ b/lib/libpthread_dbg/arch/i386/Makefile.inc
@@ -0,0 +1,5 @@
+# $FreeBSD$
+
+.PATH:	${.CURDIR}/arch/${MACHINE_ARCH}/${MACHINE_ARCH}
+
+SRCS+=	pthread_dbg_md.c
diff --git a/lib/libpthread_dbg/arch/i386/i386/pthread_dbg_md.c b/lib/libpthread_dbg/arch/i386/i386/pthread_dbg_md.c
new file mode 100644
index 0000000..593a784
--- /dev/null
+++ b/lib/libpthread_dbg/arch/i386/i386/pthread_dbg_md.c
@@ -0,0 +1,106 @@
+/*
+ * Copyright (c) 2004 David Xu <davidxu@freebsd.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <string.h>
+#include <sys/types.h>
+#include <machine/npx.h>
+#include <machine/reg.h>
+
+#include "pthread_dbg.h"
+#include "pthread_dbg_int.h"
+#include "pthread_dbg_md.h"
+
+static int has_xmm_regs;
+
+void
+td_reg_to_ucontext(struct reg *r, ucontext_t *uc)
+{
+	memcpy(&uc->uc_mcontext.mc_fs, &r->r_fs, 18*4);
+	uc->uc_mcontext.mc_gs = r->r_gs;
+}
+
+void
+td_ucontext_to_reg(ucontext_t *uc, struct reg *r)
+{
+	memcpy(&r->r_fs, &uc->uc_mcontext.mc_fs, 18*4);
+	r->r_gs = uc->uc_mcontext.mc_gs;
+}
+
+void
+td_fpreg_to_ucontext(struct fpreg* r, ucontext_t *uc)
+{
+	if (!has_xmm_regs)
+		memcpy(&uc->uc_mcontext.mc_fpstate, r,
+			sizeof(struct save87));
+	else {
+		int i;
+		struct savexmm *sx = (struct savexmm *)&uc->uc_mcontext.mc_fpstate;
+		memcpy(&sx->sv_env, &r->fpr_env, sizeof(r->fpr_env));
+		for (i = 0; i < 8; ++i)
+			memcpy(&sx->sv_fp[i].fp_acc, &r->fpr_acc[i], 10);
+	}
+}
+
+void
+td_ucontext_to_fpreg(ucontext_t *uc, struct fpreg *r)
+{
+	if (!has_xmm_regs)
+		memcpy(r, &uc->uc_mcontext.mc_fpstate, sizeof(struct save87));
+	else {
+		int i;
+		struct savexmm *sx = (struct savexmm *)&uc->uc_mcontext.mc_fpstate;
+		memcpy(&r->fpr_env, &sx->sv_env, sizeof(r->fpr_env));
+		for (i = 0; i < 8; ++i)
+			memcpy(&r->fpr_acc[i], &sx->sv_fp[i].fp_acc, 10);
+	}
+}
+
+void
+td_md_init(void)
+{
+	ucontext_t uc;
+
+	getcontext(&uc);
+	if (uc.uc_mcontext.mc_fpformat == _MC_FPFMT_XMM)
+	    has_xmm_regs = 1;
+}
+
+int
+td_reg_sstep(struct reg *reg, int step)
+{
+	unsigned int old;
+	
+	old = reg->r_eflags;
+	if (step)
+		reg->r_eflags |= 0x0100;
+	else
+		reg->r_eflags &= ~0x0100;
+	return (old != reg->r_eflags); /* changed ? */
+}
+
diff --git a/lib/libpthread_dbg/pthread_dbg.c b/lib/libpthread_dbg/pthread_dbg.c
new file mode 100644
index 0000000..426a381
--- /dev/null
+++ b/lib/libpthread_dbg/pthread_dbg.c
@@ -0,0 +1,562 @@
+/*-
+ * Copyright (c) 2004 David Xu <davidxu@freebsd.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <stddef.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <pthread.h>
+#include <thr_private.h>
+#include <sys/types.h>
+#include <sys/kse.h>
+
+#include "pthread_dbg_md.h"
+#include "pthread_dbg.h"
+#include "pthread_dbg_int.h"
+
+static void td_empty_thread_list(td_proc_t *proc);
+static int td_refresh_thread_list(td_proc_t *proc);
+static int td_get_thread(td_proc_t *proc, caddr_t addr, int type, 
+	td_thread_t **threadp);
+static void td_remove_map(td_proc_t *proc, int type);
+
+int
+td_open(td_proc_callbacks_t *cb, void *arg, td_proc_t **procp)
+{
+#define LOOKUP_SYM(proc, sym, addr) 			\
+	ret = LOOKUP(proc, sym, addr);			\
+	if (ret != 0) {					\
+		if (ret == TD_ERR_NOSYM)		\
+			ret = TD_ERR_NOLIB;		\
+		goto error;				\
+	}
+
+	td_proc_t *proc;
+	int dbg;
+	int ret;
+
+	td_md_init();
+	proc = malloc(sizeof(*proc));
+	if (proc == NULL)
+		return (TD_ERR_NOMEM);
+
+	proc->cb = cb;
+	proc->arg = arg;
+	proc->thread_activated = 0;
+	proc->thread_listgen = -1;
+	TAILQ_INIT(&proc->threads);
+
+	LOOKUP_SYM(proc, "_libkse_debug",	&proc->libkse_debug_addr);
+	LOOKUP_SYM(proc, "_thread_list",	&proc->thread_list_addr);
+	LOOKUP_SYM(proc, "_thread_listgen",	&proc->thread_listgen_addr);
+	LOOKUP_SYM(proc, "_thread_activated",	&proc->thread_activated_addr);
+/*	LOOKUP_SYM(proc, "_thread_active_kseq",	&proc->thread_active_kseq_addr);*/
+	dbg = getpid();
+	/*
+	 * If this fails it probably means we're debugging a core file and
+	 * can't write to it.
+	 * If it's something else we'll lose the next time we hit WRITE,
+	 * but not before, and that's OK.
+	 */
+	WRITE(proc, proc->libkse_debug_addr, &dbg, sizeof(int));
+
+	*procp = proc;
+	return (0);
+
+error:
+	free(proc);
+	return (ret);
+}
+
+int
+td_close(td_proc_t *proc)
+{
+	int dbg;
+
+	td_empty_thread_list(proc);
+
+	dbg = 0;
+        /*
+         * Error returns from this write are not really a problem;
+         * the process doesn't exist any more.
+         */
+	WRITE(proc, proc->libkse_debug_addr, &dbg, sizeof(int));
+
+	free(proc);
+	return 0;
+}
+
+int
+td_thr_iter(td_proc_t *proc, int (*call)(td_thread_t *, void *),
+	    void *callarg)
+{
+	int ret;
+	td_thread_t *thread;
+
+	td_refresh_thread_list(proc);
+
+	TAILQ_FOREACH(thread, &proc->threads, tle) {
+		ret = (*call)(thread, callarg);
+		if (ret != 0)
+			return (ret);
+	}
+	return (0);
+}
+
+int
+td_thr_info(td_thread_t *thread, td_thread_info_t *info)
+{
+	int ret = 0;
+	struct pthread pt;
+
+	memset(info, 0, sizeof(*info));
+	if (thread->type == TD_TYPE_UPCALL) {
+		info->thread_id = (long)thread->kthread;
+		info->thread_state = TD_STATE_RUNNING;
+		info->thread_type = TD_TYPE_UPCALL;
+		return (ret);
+	}
+
+	/* Handle normal thread */
+	ret = READ(thread->proc, thread->addr, &pt, sizeof(pt));
+	if (ret != 0)
+		return (ret);
+
+	if (pt.magic != THR_MAGIC)
+		return (TD_ERR_BADTHREAD);
+
+	info->thread_id = (long)thread->addr;
+	info->thread_addr = thread->addr;
+	info->thread_type = TD_TYPE_NORMAL;
+	switch (pt.state) {
+	case PS_RUNNING:
+		info->thread_state = TD_STATE_RUNNING;
+		break;
+	case PS_LOCKWAIT:
+		info->thread_state = TD_STATE_LOCKWAIT;
+		break;
+	case PS_MUTEX_WAIT:
+		info->thread_state = TD_STATE_MUTEXWAIT;
+		break;
+	case PS_COND_WAIT:
+		info->thread_state = TD_STATE_SLEEPING;
+		break;
+	case PS_SIGSUSPEND:
+		info->thread_state = TD_STATE_SIGSUSPEND;
+		break;
+	case PS_SIGWAIT:
+		info->thread_state = TD_STATE_SIGWAIT;
+		break;
+	case PS_JOIN:
+		info->thread_state = TD_STATE_JOIN;
+		break;
+	case PS_SUSPENDED:
+		info->thread_state = TD_STATE_SUSPENDED;
+		break;
+	case PS_DEAD:
+		info->thread_state = TD_STATE_DEAD;
+		break;
+	case PS_DEADLOCK:
+		info->thread_state = TD_STATE_DEADLOCK;
+		break;
+	default:
+		info->thread_state = TD_STATE_UNKNOWN;
+		break;
+	}
+	
+	info->thread_scope = (pt.attr.flags & PTHREAD_SCOPE_SYSTEM) ?
+		TD_SCOPE_SYSTEM : TD_SCOPE_PROCESS;
+	info->thread_stack.ss_sp = pt.attr.stackaddr_attr;
+	info->thread_stack.ss_size = pt.attr.stacksize_attr;
+	info->thread_joiner = (caddr_t)pt.joiner;
+	info->thread_errno = pt.error;
+	info->thread_sigmask = pt.sigmask;
+	info->thread_sigpend = pt.sigpend;
+	info->thread_sigstk = pt.sigstk;
+	info->thread_base_priority = pt.base_priority;
+	info->thread_inherited_priority = pt.inherited_priority;
+	info->thread_active_priority = pt.active_priority;
+	info->thread_cancelflags = pt.cancelflags;
+	info->thread_retval = pt.join_status.ret;
+	info->thread_tls = (caddr_t)pt.specific;
+	info->thread_tlscount = pt.specific_data_count;
+	return (0);
+}
+
+int
+td_thr_getregs(td_thread_t *thread, int regset, void *buf)
+{
+	td_proc_t *proc = thread->proc;
+	caddr_t tmbx_addr, ptr;
+	struct kse_thr_mailbox tmbx;
+	int ret;
+
+	if (regset != 0 && regset != 1)
+		return (TD_ERR_INVAL);
+
+	if (thread->kthread != NULL)
+		return GETREGS(proc, regset, thread->kthread, buf);
+
+	tmbx_addr = thread->tcb_addr + offsetof(struct tcb, tcb_tmbx);
+	ptr = tmbx_addr + offsetof(struct kse_thr_mailbox, tm_kthread);
+	ret = READ(proc, ptr, &ptr, sizeof(ptr));
+	if (ret != 0)
+		return (ret);
+	if (ptr != NULL)
+		return GETREGS(proc, regset, ptr, buf);
+	ret = READ(proc, tmbx_addr, &tmbx, sizeof(tmbx));
+	if (ret != 0)
+		return (ret);
+	if (regset == 0)
+		td_ucontext_to_reg(&tmbx.tm_context, (struct reg *)buf);
+	else
+		td_ucontext_to_fpreg(&tmbx.tm_context, (struct fpreg *)buf);
+	return (0);
+}
+
+int
+td_thr_setregs(td_thread_t *thread, int regset, void *buf)
+{
+	td_proc_t *proc = thread->proc;
+	caddr_t tmbx_addr, ptr;
+	struct kse_thr_mailbox tmbx;
+	int ret;
+	
+	if (regset != 0 && regset != 1)
+		return (TD_ERR_INVAL);
+
+	if (thread->kthread != NULL)
+		return SETREGS(proc, regset, thread->kthread, buf);
+
+	tmbx_addr = thread->tcb_addr + offsetof(struct tcb, tcb_tmbx);
+	ptr = tmbx_addr + offsetof(struct kse_thr_mailbox, tm_kthread);
+	ret = READ(proc, ptr, &ptr, sizeof(ptr));
+	if (ret != 0)
+		return (ret);
+	if (ptr != NULL)
+		return SETREGS(proc, regset, ptr, buf);
+
+	/*
+	 * Read a copy of context, this makes sure that registers
+	 * not covered by structure reg won't be clobbered
+	 */
+	ret = READ(proc, tmbx_addr, &tmbx, sizeof(tmbx));
+	if (ret != 0)
+		return (ret);
+	if (regset == 0)
+		td_reg_to_ucontext((struct reg *)buf, &tmbx.tm_context);
+	else
+		td_fpreg_to_ucontext((struct fpreg *)buf, &tmbx.tm_context);
+	return (WRITE(proc, tmbx_addr, &tmbx, sizeof(tmbx)));
+}
+
+int
+td_thr_getname(td_thread_t *thread, char *name, int len)
+{
+	int ret;
+	caddr_t nameaddr;
+	
+	if ((ret = READ(thread->proc,
+			thread->addr + offsetof(struct pthread, name),
+			&nameaddr, sizeof(nameaddr))) != 0)
+		return (ret);
+
+	if (nameaddr == 0)
+		name[0] = '\0';
+	else if ((ret = READ_STRING(thread->proc, nameaddr,
+				    name, len)) != 0)
+		return (ret);
+
+	return (0);
+}
+
+int
+td_activated(td_proc_t *proc)
+{
+	if (proc->thread_activated)
+		return (1);
+	READ(proc, proc->thread_activated_addr, &proc->thread_activated,
+	     sizeof(proc->thread_activated));
+	return (proc->thread_activated != 0);
+}
+
+int
+td_map_lwp2thr(td_proc_t *proc, void *lwp, td_thread_t **threadp)
+{
+	int ret;
+	caddr_t next, ptr;
+	td_thread_t *thread;
+	TAILQ_HEAD(, pthread) thread_list;
+	
+	ret = READ(proc, proc->thread_list_addr, &thread_list,
+		   sizeof(thread_list));
+	if (ret != 0)
+		return (ret);
+	/*
+	 * We have to iterate through thread list to find which
+	 * userland thread is running on the kernel thread.
+	 */
+	next = (caddr_t)thread_list.tqh_first;
+	while (next != NULL) {
+		ret = READ(proc, next + offsetof(struct pthread, tcb),
+			   &ptr, sizeof(ptr));
+		if (ret != 0)
+			return (ret);
+		ptr += offsetof(struct tcb, tcb_tmbx.tm_kthread);
+		ret = READ(proc, ptr, &ptr, sizeof(ptr));
+		if (ret != 0)
+			return (ret);
+		if (ptr == lwp) {
+			ret = td_get_thread(proc, next, TD_TYPE_NORMAL,
+				 &thread);
+			if (ret != 0)
+				return (ret);
+			*threadp = thread;
+			return (0);
+		}
+
+		/* get next thread */
+		ret = READ(proc,
+			   next + offsetof(struct pthread, tle.tqe_next), 
+			   &next, sizeof(next));
+		if (ret != 0)
+			return (ret);
+	}
+	return (TD_ERR_NOOBJ);
+}
+
+int
+td_map_id2thr(td_proc_t *proc, long threadid, td_thread_t **threadp)
+{
+	td_thread_t *thread;
+
+	td_refresh_thread_list(proc);
+	
+	TAILQ_FOREACH(thread, &proc->threads, tle) {
+		if (thread->type == TD_TYPE_UPCALL) {
+			if ((long)thread->kthread == threadid)
+				break;
+		} else if ((long)thread->addr == threadid)
+			break;
+	}
+	if (thread) {
+		*threadp = thread;
+		return (0);
+	}
+	return (TD_ERR_NOOBJ);
+}
+
+int
+td_thr_sstep(td_thread_t *thread, int step)
+{
+	int ret;
+	uint32_t tmp;
+	struct reg reg;
+	td_proc_t *proc;
+	caddr_t kthread;
+
+	proc = thread->proc;
+	if ((kthread=thread->kthread) != NULL)
+		return SSTEP(proc, kthread, step);
+
+	if (thread->step == step)
+		return (0);
+
+	/* Clear or set single step flag in thread mailbox */
+	tmp = step ? TMDF_SSTEP : 0;
+	ret = WRITE(proc, thread->tcb_addr + offsetof(struct tcb,
+		   tcb_tmbx.tm_dflags), &tmp, sizeof(tmp));
+
+	/* Get kthread */
+	ret = READ(proc, thread->tcb_addr + offsetof(struct tcb,
+	           tcb_tmbx.tm_kthread), &kthread, sizeof(kthread));
+	if (ret != 0)
+		return (ret);
+	thread->step = step;
+	if (kthread != NULL)
+		return SSTEP(proc, kthread, step);
+
+	/*
+	 * context is in userland, some architectures store
+	 * single step status in registers, we should change
+	 * these registers.
+	 */
+	ret = td_thr_getregs(thread, 0, &reg);
+	if (ret == 0) {
+		/* only write out if it is really changed. */
+		if (td_reg_sstep(&reg, step) != 0)
+			ret = td_thr_setregs(thread, 0, &reg);
+	}
+	return (ret);
+}
+
+void
+td_remove_lwp_map(td_proc_t *proc)
+{
+	td_remove_map(proc, TD_TYPE_UPCALL);
+}
+
+static void
+td_remove_map(td_proc_t *proc, int type)
+{
+	td_thread_t *thread, *next;
+
+	for (thread = TAILQ_FIRST(&proc->threads); thread; thread = next) {
+		next = TAILQ_NEXT(thread, tle);
+		if (type == type)
+			TAILQ_REMOVE(&proc->threads, thread, tle);
+	}
+}
+
+static int
+td_refresh_thread_list(td_proc_t *proc)
+{
+	int ret, gen;
+	caddr_t next;
+	td_thread_t *thread;
+	TAILQ_HEAD(, pthread) thread_list;
+	
+	ret = READ(proc, proc->thread_listgen_addr, &gen, sizeof(gen));
+	if (ret != 0)
+		return (ret);
+	if (gen == proc->thread_listgen)
+		return (TD_ERR_OK);
+	proc->thread_listgen = gen;
+
+	td_remove_map(proc, TD_TYPE_NORMAL);
+
+	ret = READ(proc, proc->thread_list_addr, &thread_list,
+		 sizeof(thread_list));
+	if (ret != 0)
+		return (ret);
+	next = (caddr_t)thread_list.tqh_first;
+	while (next != NULL) {
+		ret = td_get_thread(proc, next, TD_TYPE_NORMAL, &thread);
+		if (ret != 0)
+			return (ret);
+		ret = READ(proc,
+			   next + offsetof(struct pthread, tle.tqe_next), 
+			   &next, sizeof(next));
+		if (ret != 0)
+			return (ret);
+	}
+	return (0);
+}
+
+static void
+td_empty_thread_list(td_proc_t *proc)
+{
+	td_thread_t *thread;
+
+	while ((thread = TAILQ_FIRST(&proc->threads)) != NULL) {
+		TAILQ_REMOVE(&proc->threads, thread, tle);
+		free(thread);
+	}
+}
+
+static int
+td_get_thread(td_proc_t *proc, caddr_t addr, int type, td_thread_t **threadp)
+{
+	td_thread_t *thread;
+	caddr_t tcb_addr;
+	int ret;
+
+	TAILQ_FOREACH(thread, &proc->threads, tle) {
+		if (type == TD_TYPE_UPCALL) {
+			/* match upcall thread */
+			if (thread->kthread == addr)
+				break;
+		} else {
+			/* match normal thread */
+			if (thread->addr == addr)
+				break;
+		}
+	}
+
+	if (thread == NULL) {
+		tcb_addr = NULL;
+		if (type != TD_TYPE_UPCALL) {
+			ret = READ(proc, addr + offsetof(struct pthread, tcb),
+			     &tcb_addr,	sizeof(tcb_addr));
+			if (ret)
+				return (ret);
+		}
+		thread = malloc(sizeof(*thread));
+		if (thread == NULL)
+			return (TD_ERR_NOMEM);
+		thread->proc = proc;
+		thread->step = -1;
+		thread->tcb_addr = tcb_addr;
+		if (type == TD_TYPE_NORMAL) {
+			thread->addr = addr;
+			thread->kthread = NULL;
+		} else {
+			thread->addr = NULL;
+			thread->kthread = addr;
+		}
+		thread->type = type;
+		TAILQ_INSERT_TAIL(&proc->threads, thread, tle);
+	}
+	*threadp = thread;
+	return (0);
+}
+
+struct string_map {
+	int num;
+	char *str;
+};
+
+char *
+td_err_string (int errcode)
+{
+	static struct string_map err_table[] = {
+	 {TD_ERR_OK, "generic \"call succeeded\""},
+	 {TD_ERR_ERR, "generic error."},
+	 {TD_ERR_NOSYM, "symbol not found"},
+	 {TD_ERR_NOOBJ, "no object can be found to satisfy query"},
+	 {TD_ERR_BADTHREAD, "thread can not answer request"},
+	 {TD_ERR_INUSE, "debugging interface already in use for this process"},
+	 {TD_ERR_NOLIB, "process is not using libpthread"},
+	 {TD_ERR_NOMEM, "out of memory"},
+	 {TD_ERR_IO, "process callback error"},
+	 {TD_ERR_INVAL, "invalid argument"},
+	};
+
+	const int err_size = sizeof(err_table) / sizeof (struct string_map);
+	int i;
+	static char buf[90];
+
+	for (i = 0; i < err_size; i++)
+		if (err_table[i].num == errcode)
+			return err_table[i].str;
+
+	sprintf (buf, "Unknown thread library debug error code: %d", errcode);
+
+	return buf;
+}
diff --git a/lib/libpthread_dbg/pthread_dbg.h b/lib/libpthread_dbg/pthread_dbg.h
new file mode 100644
index 0000000..0f807fc
--- /dev/null
+++ b/lib/libpthread_dbg/pthread_dbg.h
@@ -0,0 +1,139 @@
+/*
+ * Copyright (c) 2004 David Xu <davidxu@freebsd.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+
+#ifndef _PTHREAD_DBG_H
+#define _PTHREAD_DBG_H
+
+#include <sys/types.h>
+#include <signal.h>
+
+typedef struct td_proc		td_proc_t;
+typedef struct td_thread	td_thread_t;
+
+typedef struct td_proc_callbacks {
+	int (*proc_read)(void *arg, caddr_t addr, void *buf, size_t size);
+	int (*proc_readstring)(void *arg, caddr_t addr, void *buf, size_t size);
+	int (*proc_write)(void *arg, caddr_t addr, void *buf, size_t size);
+	int (*proc_lookup)(void *arg, char *sym, caddr_t *addr);
+	int (*proc_regsize)(void *arg, int regset, size_t *size);
+	int (*proc_getregs)(void *arg, int regset, void *lwp, void *buf);
+	int (*proc_setregs)(void *arg, int regset, void *lwp, void *buf);
+	int (*proc_sstep)(void *arg, void *lwp, int onoff);
+} td_proc_callbacks_t;
+
+typedef struct td_thread_info {
+	caddr_t	thread_addr;		/* Address of data structure */
+	int	thread_state;		/* TD_STATE_*; see below */
+	int	thread_type;		/* TD_TYPE_*; see below */
+	int	thread_scope;		/* TD_SCOPE_*; see below */
+	long	thread_id;
+	stack_t	thread_stack;
+	caddr_t	thread_joiner;
+	caddr_t	thread_tls;
+	int	thread_tlscount;
+	int	thread_errno;
+	sigset_t thread_sigmask;
+	sigset_t thread_sigpend;
+	stack_t	thread_sigstk;
+	char	thread_base_priority;
+	char	thread_inherited_priority;
+	char	thread_active_priority;
+	int	thread_cancelflags;	/* TD_CANCEL_*; see below */
+	caddr_t	thread_retval;
+	long	pad[32];
+} td_thread_info_t;
+
+#define TD_STATE_UNKNOWN	0
+#define TD_STATE_RUNNING	1
+#define TD_STATE_LOCKWAIT	2
+#define TD_STATE_MUTEXWAIT	3
+#define TD_STATE_CONDWAIT	4
+#define TD_STATE_SLEEPING	5
+#define TD_STATE_SIGSUSPEND	6
+#define TD_STATE_SIGWAIT	7
+#define TD_STATE_JOIN		8
+#define TD_STATE_SUSPENDED	9
+#define TD_STATE_DEAD		10
+#define TD_STATE_DEADLOCK	11
+
+#define TD_TYPE_NORMAL		0
+#define TD_TYPE_UPCALL		1
+
+#define TD_SCOPE_PROCESS	0
+#define TD_SCOPE_SYSTEM		1
+
+#define TD_CANCEL_DISABLED	1
+#define TD_CANCEL_ASYNCHRONOUS	2
+#define TD_CANCEL_AT_POINT	4
+#define TD_CANCEL_CANCELLING	8
+#define TD_CANCEL_NEEDED	10
+
+/* Error return codes */
+#define TD_ERR_OK		0
+#define TD_ERR_ERR		1  /* Generic error */
+#define TD_ERR_NOSYM		2  /* Symbol not found (proc_lookup) */
+#define TD_ERR_NOOBJ		3  /* No object matched the request */
+#define TD_ERR_BADTHREAD        4  /* Thread structure damaged */
+#define TD_ERR_INUSE		5  /* The process is already being debugged */
+#define TD_ERR_NOLIB		6  /* The process is not using libpthread */
+#define TD_ERR_NOMEM		7  /* malloc() failed */
+#define TD_ERR_IO		8  /* A callback failed to read or write */
+#define TD_ERR_INVAL		9  /* Invalid parameter */
+
+/* Make a connection to a threaded process */
+int td_open(td_proc_callbacks_t *, void *arg, td_proc_t **);
+
+/* Release proc object */
+int td_close(td_proc_t *);
+
+/* Iterate over the threads in the process */
+int td_thr_iter(td_proc_t *, int (*)(td_thread_t *, void *), void *);
+
+/* Check if threaded mode is activated */
+int td_activated(td_proc_t *);
+
+/* Get information on a thread */
+int td_thr_info(td_thread_t *, td_thread_info_t *);
+
+/* Get name of a thread */
+int td_thr_getname(td_thread_t *, char *, int);
+
+/* Get registers set of a thread */
+int td_thr_getregs(td_thread_t *, int, void *);
+
+/* Set registers set of a thread */
+int td_thr_setregs(td_thread_t *, int, void *);
+
+/* Set/clear single step status */
+int td_thr_sstep(td_thread_t *, int step);
+
+/* Map error code to error message */
+char *td_err_string (int errcode);
+
+#endif
+
diff --git a/lib/libpthread_dbg/pthread_dbg_int.h b/lib/libpthread_dbg/pthread_dbg_int.h
new file mode 100644
index 0000000..b6c4e3d
--- /dev/null
+++ b/lib/libpthread_dbg/pthread_dbg_int.h
@@ -0,0 +1,68 @@
+/*
+ * Copyright (c) 2004 David Xu <davidxu@freebsd.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+
+#ifndef _PTHREAD_DBG_INT_H
+#define _PTHREAD_DBG_INT_H
+
+#include <sys/queue.h>
+#include <sys/ucontext.h>
+
+struct td_proc {
+	td_proc_callbacks_t		*cb;
+	void				*arg;
+	pid_t				pid;
+	caddr_t				libkse_debug_addr;
+	caddr_t				thread_list_addr;
+	caddr_t				thread_listgen_addr;
+	caddr_t				thread_activated_addr;
+	caddr_t				thread_active_kseq_addr;
+	int				thread_activated;
+	int				thread_listgen;
+	TAILQ_HEAD(, td_thread)		threads;
+};
+
+struct td_thread {
+        td_proc_t	*proc;
+        caddr_t		addr;
+	caddr_t		tcb_addr;
+        void		*kthread;
+	int		type;
+	int		step;
+        TAILQ_ENTRY(td_thread) tle;
+};
+
+#define READ(proc, addr, buf, size) ((proc)->cb->proc_read((proc)->arg, (addr), (buf), (size)))
+#define READ_STRING(proc, addr, buf, size) ((proc)->cb->proc_read((proc)->arg, (addr), (buf), (size)))
+#define WRITE(proc, addr, buf, size) ((proc)->cb->proc_write((proc)->arg, (addr), (buf), (size)))
+#define LOOKUP(proc, sym, addr) ((proc)->cb->proc_lookup((proc)->arg, (sym), (addr)))
+#define GETREGS(proc, regset, lwp, buf) ((proc)->cb->proc_getregs((proc)->arg, (regset), (lwp), (buf)))
+#define SETREGS(proc, regset, lwp, buf) ((proc)->cb->proc_setregs((proc)->arg, (regset), (lwp), (buf)))
+#define SSTEP(proc, lwp, on) ((proc)->cb->proc_sstep((proc)->arg, (lwp), (on)))
+
+#endif
+