Break out stack(9) from ddb(4):

- Introduce per-architecture stack_machdep.c to hold stack_save(9).
- Introduce per-architecture machine/stack.h to capture any common
  definitions required between db_trace.c and stack_machdep.c.
- Add new kernel option "options STACK"; we will build in stack(9) if it is
  defined, or also if "options DDB" is defined to provide compatibility
  with existing users of stack(9).

Add new stack_save_td(9) function, which allows the capture of a stacktrace
of another thread rather than the current thread, which the existing
stack_save(9) was limited to.  It requires that the thread be neither
swapped out nor running, which is the responsibility of the consumer to
enforce.

Update stack(9) man page.

Build tested:	amd64, arm, i386, ia64, powerpc, sparc64, sun4v
Runtime tested:	amd64 (rwatson), arm (cognet), i386 (rwatson)

3 files changed, 119 insertions, 25 deletions

diff --git a/sys/arm/arm/db_trace.c b/sys/arm/arm/db_trace.c
index e9ce328..6913df6 100644
--- a/sys/arm/arm/db_trace.c
+++ b/sys/arm/arm/db_trace.c
@@ -43,14 +43,13 @@ __FBSDID("$FreeBSD$");
 #include <machine/cpufunc.h>
 #include <machine/db_machdep.h>
 #include <machine/pcb.h>
+#include <machine/stack.h>
 #include <machine/vmparam.h>
 #include <ddb/ddb.h>
 #include <ddb/db_access.h>
 #include <ddb/db_sym.h>
 #include <ddb/db_output.h>
 
-#define INKERNEL(va)	(((vm_offset_t)(va)) >= VM_MIN_KERNEL_ADDRESS)
-
 /*
  * APCS stack frames are awkward beasts, so I don't think even trying to use
  * a structure to represent them is a good idea.
@@ -79,11 +78,6 @@ __FBSDID("$FreeBSD$");
  * fields are actually present.
  */
 
-#define FR_SCP	(0)
-#define FR_RLV	(-1)
-#define FR_RSP	(-2)
-#define FR_RFP	(-3)
-
 static void
 db_stack_trace_cmd(db_expr_t addr, db_expr_t count)
 {
@@ -215,21 +209,3 @@ db_trace_self(void)
 {
 	db_trace_thread(curthread, -1);
 }
-
-void
-stack_save(struct stack *st)
-{
-	vm_offset_t callpc;
-	u_int32_t *frame;
-
-	stack_zero(st);
-	frame = (u_int32_t *)__builtin_frame_address(0);
-	while (1) {
-		if (!INKERNEL(frame))
-			break;
-		callpc = frame[FR_SCP];
-		if (stack_put(st, callpc) == -1)
-			break;
-		frame = (u_int32_t *)(frame[FR_RFP]);
-	}
-}
diff --git a/sys/arm/arm/stack_machdep.c b/sys/arm/arm/stack_machdep.c
new file mode 100644
index 0000000..a6032bc
--- /dev/null
+++ b/sys/arm/arm/stack_machdep.c
@@ -0,0 +1,76 @@
+/*-
+ * Copyright (c) 2005 Antoine Brodin
+ * 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 <sys/systm.h>
+#include <sys/param.h>
+#include <sys/proc.h>
+#include <sys/stack.h>
+
+#include <machine/vmparam.h>
+#include <machine/pcb.h>
+#include <machine/stack.h>
+
+static void
+stack_capture(struct stack *st, u_int32_t *frame)
+{
+	vm_offset_t callpc;
+
+	stack_zero(st);
+	while (1) {
+		if (!INKERNEL(frame))
+			break;
+		callpc = frame[FR_SCP];
+		if (stack_put(st, callpc) == -1)
+			break;
+		frame = (u_int32_t *)(frame[FR_RFP]);
+	}
+}
+
+void
+stack_save_td(struct stack *st, struct thread *td)
+{
+	u_int32_t *frame;
+
+	if (TD_IS_SWAPPED(td))
+		panic("stack_save_td: swapped");
+	if (TD_IS_RUNNING(td))
+		panic("stack_save_td: running");
+
+	frame = (u_int32_t *)td->td_pcb->un_32.pcb32_r11;
+	stack_capture(st, frame);
+}
+
+void
+stack_save(struct stack *st)
+{
+	u_int32_t *frame;
+
+	frame = (u_int32_t *)__builtin_frame_address(0);
+	stack_capture(st, frame);
+}
diff --git a/sys/arm/include/stack.h b/sys/arm/include/stack.h
new file mode 100644
index 0000000..32ff5a9
--- /dev/null
+++ b/sys/arm/include/stack.h
@@ -0,0 +1,42 @@
+/*-
+ * Copyright (c) 2000, 2001 Ben Harris
+ * Copyright (c) 1996 Scott K. Stevens
+ *
+ * Mach Operating System
+ * Copyright (c) 1991,1990 Carnegie Mellon University
+ * All Rights Reserved.
+ * 
+ * Permission to use, copy, modify and distribute this software and its
+ * documentation is hereby granted, provided that both the copyright
+ * notice and this permission notice appear in all copies of the
+ * software, derivative works or modified versions, and any portions
+ * thereof, and that both notices appear in supporting documentation.
+ * 
+ * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
+ * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
+ * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
+ * 
+ * Carnegie Mellon requests users of this software to return to
+ * 
+ *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
+ *  School of Computer Science
+ *  Carnegie Mellon University
+ *  Pittsburgh PA 15213-3890
+ * 
+ * any improvements or extensions that they make and grant Carnegie the
+ * rights to redistribute these changes.
+ *
+ * $FreeBSD$
+ */
+
+#ifndef _MACHINE_STACK_H_
+#define	_MACHINE_STACK_H_
+
+#define INKERNEL(va)	(((vm_offset_t)(va)) >= VM_MIN_KERNEL_ADDRESS)
+
+#define FR_SCP	(0)
+#define FR_RLV	(-1)
+#define FR_RSP	(-2)
+#define FR_RFP	(-3)
+
+#endif /* !_MACHINE_STACK_H_ */