Add a process library with some stubs that the DTrace client needs.

These will be fleshed out as part of the DTrace userland tracing
development.

For now, the kernel tracing part of DTrace requires minimal functionality
for this library.

The API for this library is deliberately different from the libproc in
OpenSolaris due to licensing restrictions.

5 files changed, 473 insertions, 0 deletions

diff --git a/lib/libproc/_libproc.h b/lib/libproc/_libproc.h
new file mode 100644
index 0000000..536227e
--- /dev/null
+++ b/lib/libproc/_libproc.h
@@ -0,0 +1,43 @@
+/*-
+ * Copyright (c) 2008 John Birrell (jb@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.
+ *
+ * $FreeBSD$
+ */
+
+#include <sys/cdefs.h>
+#include <sys/param.h>
+#include <sys/types.h>
+#include <sys/event.h>
+#include <sys/ptrace.h>
+
+#include "libproc.h"
+
+struct proc_handle {
+	pid_t	pid;			/* Process ID. */
+	int	kq;			/* Kernel event queue ID. */
+	int	flags;			/* Process flags. */
+	int	status;			/* Process status (PS_*). */
+};
+
diff --git a/lib/libproc/libproc.h b/lib/libproc/libproc.h
new file mode 100644
index 0000000..c67cfe6
--- /dev/null
+++ b/lib/libproc/libproc.h
@@ -0,0 +1,70 @@
+/*-
+ * Copyright (c) 2008 John Birrell (jb@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	_LIBPROC_H_
+#define	_LIBPROC_H_
+
+#include <gelf.h>
+
+struct proc_handle;
+
+/* Values returned by proc_state(). */
+#define PS_IDLE		1
+#define PS_STOP		2
+#define PS_RUN		3
+#define PS_UNDEAD	4
+#define PS_DEAD		5
+#define PS_LOST		6
+
+typedef struct prmap {
+	uintptr_t	pr_vaddr;	/* Virtual address. */
+} prmap_t;
+
+/* Function prototype definitions. */
+__BEGIN_DECLS
+
+const prmap_t *proc_addr2map(struct proc_handle *, uintptr_t);
+const prmap_t *proc_name2map(struct proc_handle *, const char *);
+char	*proc_objname(struct proc_handle *, uintptr_t, char *, size_t);
+int	proc_addr2sym(struct proc_handle *, uintptr_t, char *, size_t, GElf_Sym *);
+int	proc_attach(pid_t pid, int flags, struct proc_handle **pphdl);
+int	proc_continue(struct proc_handle *);
+int	proc_clearflags(struct proc_handle *, int);
+int	proc_create(const char *, char * const *, struct proc_handle **);
+int	proc_detach(struct proc_handle *);
+int	proc_getflags(struct proc_handle *);
+int	proc_name2sym(struct proc_handle *, const char *, const char *, GElf_Sym *);
+int	proc_setflags(struct proc_handle *, int);
+int	proc_state(struct proc_handle *);
+int	proc_wait(struct proc_handle *);
+pid_t	proc_getpid(struct proc_handle *);
+void	proc_free(struct proc_handle *);
+
+__END_DECLS
+
+#endif /* !_LIBPROC_H_ */
diff --git a/lib/libproc/proc_create.c b/lib/libproc/proc_create.c
new file mode 100644
index 0000000..8648999
--- /dev/null
+++ b/lib/libproc/proc_create.c
@@ -0,0 +1,159 @@
+/*-
+ * Copyright (c) 2008 John Birrell (jb@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.
+ *
+ * $FreeBSD$
+ */
+
+#include "_libproc.h"
+#include <err.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/wait.h>
+
+int
+proc_attach(pid_t pid, int flags, struct proc_handle **pphdl)
+{
+	struct proc_handle *phdl;
+	struct kevent kev;
+	int error = 0;
+	int status;
+
+	if (pid == 0 || pphdl == NULL)
+		return (EINVAL);
+
+	/*
+	 * Allocate memory for the process handle, a structure containing
+	 * all things related to the process.
+	 */
+	if ((phdl = malloc(sizeof(struct proc_handle))) == NULL)
+		return (ENOMEM);
+
+	memset(phdl, 0, sizeof(struct proc_handle));
+	phdl->pid = pid;
+	phdl->flags = flags;
+	phdl->status = PS_RUN;
+
+	EV_SET(&kev, pid, EVFILT_PROC, EV_ADD | EV_ONESHOT, NOTE_EXIT,
+	    0, NULL);
+
+	if ((phdl->kq = kqueue()) == -1)
+		err(1, "ERROR: cannot create kernel evet queue");
+
+	if (kevent(phdl->kq, &kev, 1, NULL, 0, NULL) < 0)
+		err(2, "ERROR: cannot monitor child process %d", pid);
+
+	if (ptrace(PT_ATTACH, phdl->pid, NULL, 0) != 0)
+		error = errno;
+
+	/* Wait for the child process to stop. */
+	else if (waitpid(pid, &status, WUNTRACED) == -1)
+		err(3, "ERROR: child process %d didn't stop as expected", pid);
+
+	/* Check for an unexpected status. */
+	else if (WIFSTOPPED(status) == 0)
+		err(4, "ERROR: child process %d status 0x%x", pid, status);
+	else
+		phdl->status = PS_STOP;
+
+	if (error)
+		proc_free(phdl);
+	else
+		*pphdl = phdl;
+
+	return (error);
+}
+
+int
+proc_create(const char *file, char * const *argv, struct proc_handle **pphdl)
+{
+	struct proc_handle *phdl;
+	struct kevent kev;
+	int error = 0;
+	int status;
+	pid_t pid;
+
+	/*
+	 * Allocate memory for the process handle, a structure containing
+	 * all things related to the process.
+	 */
+	if ((phdl = malloc(sizeof(struct proc_handle))) == NULL)
+		return (ENOMEM);
+
+	/* Fork a new process. */
+	if ((pid = fork()) == -1)
+		error = errno;
+	else if (pid == 0) {
+		/* The child expects to be traced. */
+		if (ptrace(PT_TRACE_ME, 0, 0, 0) != 0)
+			_exit(1);
+
+		/* Execute the specified file: */
+		execvp(file, argv);
+
+		/* Couldn't execute the file. */
+		_exit(2);
+	} else {
+		/* The parent owns the process handle. */
+		memset(phdl, 0, sizeof(struct proc_handle));
+		phdl->pid = pid;
+		phdl->status = PS_IDLE;
+
+		EV_SET(&kev, pid, EVFILT_PROC, EV_ADD | EV_ONESHOT, NOTE_EXIT,
+		    0, NULL);
+
+		if ((phdl->kq = kqueue()) == -1)
+                	err(1, "ERROR: cannot create kernel evet queue");
+
+        	if (kevent(phdl->kq, &kev, 1, NULL, 0, NULL) < 0)
+                	err(2, "ERROR: cannot monitor child process %d", pid);
+
+		/* Wait for the child process to stop. */
+		if (waitpid(pid, &status, WUNTRACED) == -1)
+                	err(3, "ERROR: child process %d didn't stop as expected", pid);
+
+		/* Check for an unexpected status. */
+		if (WIFSTOPPED(status) == 0)
+                	err(4, "ERROR: child process %d status 0x%x", pid, status);
+		else
+			phdl->status = PS_STOP;
+	}
+
+	if (error)
+		proc_free(phdl);
+	else
+		*pphdl = phdl;
+
+	return (error);
+}
+
+void
+proc_free(struct proc_handle *phdl)
+{
+	free(phdl);
+}
diff --git a/lib/libproc/proc_sym.c b/lib/libproc/proc_sym.c
new file mode 100644
index 0000000..c17c515
--- /dev/null
+++ b/lib/libproc/proc_sym.c
@@ -0,0 +1,68 @@
+/*-
+ * Copyright (c) 2008 John Birrell (jb@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.
+ *
+ * $FreeBSD$
+ */
+
+#include "_libproc.h"
+#include <stdio.h>
+
+char *
+proc_objname(struct proc_handle *p, uintptr_t addr, char *objname,
+    size_t objnamesz)
+{
+printf("%s(%d): Not implemented. p %p addr 0x%lx objname %p objnamesz %zd\n",__func__,__LINE__,p,(u_long) addr,objname,objnamesz);
+	return (NULL);
+}
+
+const prmap_t *
+proc_addr2map(struct proc_handle *p, uintptr_t addr)
+{
+printf("%s(%d): Not implemented. p %p addr 0x%lx\n",__func__,__LINE__,p,(u_long) addr);
+	return (NULL);
+}
+
+int
+proc_addr2sym(struct proc_handle *p, uintptr_t addr, char *name,
+    size_t namesz, GElf_Sym *sym)
+{
+printf("%s(%d): Not implemented. p %p addr 0x%lx name %p namesz %zd sym %p\n",__func__,__LINE__,p,(u_long) addr,name,namesz,sym);
+	return (0);
+}
+
+const prmap_t *
+proc_name2map(struct proc_handle *p, const char *name)
+{
+printf("%s(%d): Not implemented. p %p name %p\n",__func__,__LINE__,p,name);
+	return (NULL);
+}
+
+int
+proc_name2sym(struct proc_handle *p, const char *object, const char *symbol,
+    GElf_Sym *sym)
+{
+printf("%s(%d): Not implemented. p %p object %p symbol %p sym %p\n",__func__,__LINE__,p,object,symbol,sym);
+	return (0);
+}
diff --git a/lib/libproc/proc_util.c b/lib/libproc/proc_util.c
new file mode 100644
index 0000000..0e7020e
--- /dev/null
+++ b/lib/libproc/proc_util.c
@@ -0,0 +1,133 @@
+/*-
+ * Copyright (c) 2008 John Birrell (jb@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.
+ *
+ * $FreeBSD$
+ */
+
+#include "_libproc.h"
+#include <errno.h>
+#include <unistd.h>
+#include <sys/ptrace.h>
+#include <sys/wait.h>
+#include <stdio.h>
+
+int
+proc_clearflags(struct proc_handle *phdl, int mask)
+{
+	if (phdl == NULL)
+		return (EINVAL);
+
+	phdl->flags &= ~mask;
+
+	return (0);
+}
+
+int
+proc_continue(struct proc_handle *phdl)
+{
+	if (phdl == NULL)
+		return (EINVAL);
+
+	if (ptrace(PT_CONTINUE, phdl->pid, (caddr_t)(uintptr_t) 1, 0) != 0)
+		return (errno);
+
+	phdl->status = PS_RUN;
+
+	return (0);
+}
+
+int
+proc_detach(struct proc_handle *phdl)
+{
+	if (phdl == NULL)
+		return (EINVAL);
+
+	if (ptrace(PT_DETACH, phdl->pid, 0, 0) != 0)
+		return (errno);
+
+	return (0);
+}
+
+int
+proc_getflags(struct proc_handle *phdl)
+{
+	if (phdl == NULL)
+		return (-1);
+
+	return(phdl->flags);
+}
+
+int
+proc_setflags(struct proc_handle *phdl, int mask)
+{
+	if (phdl == NULL)
+		return (EINVAL);
+
+	phdl->flags |= mask;
+
+	return (0);
+}
+
+int
+proc_state(struct proc_handle *phdl)
+{
+	if (phdl == NULL)
+		return (-1);
+
+	return (phdl->status);
+}
+
+int
+proc_wait(struct proc_handle *phdl)
+{
+	int status = 0;
+	struct kevent kev;
+
+	if (phdl == NULL)
+		return (EINVAL);
+
+	if (kevent(phdl->kq, NULL, 0, &kev, 1, NULL) <= 0)
+		return (0);
+
+	switch (kev.filter) {
+	/* Child has exited */
+	case EVFILT_PROC:  /* target has exited */
+		phdl->status = PS_UNDEAD;
+		break;
+	default:
+		break;
+	}
+
+	return (status);
+}
+
+pid_t
+proc_getpid(struct proc_handle *phdl)
+{
+	if (phdl == NULL)
+		return (-1);
+
+	return (phdl->pid);
+}