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)

1 files changed, 1 insertions, 38 deletions

diff --git a/sys/amd64/amd64/db_trace.c b/sys/amd64/amd64/db_trace.c
index 548c36c..c4e552d 100644
--- a/sys/amd64/amd64/db_trace.c
+++ b/sys/amd64/amd64/db_trace.c
@@ -38,6 +38,7 @@ __FBSDID("$FreeBSD$");
 #include <machine/md_var.h>
 #include <machine/pcb.h>
 #include <machine/reg.h>
+#include <machine/stack.h>
 
 #include <vm/vm.h>
 #include <vm/vm_param.h>
@@ -177,18 +178,6 @@ db_ss(struct db_variable *vp, db_expr_t *valuep, int op)
 	return (1);
 }
 
-/*
- * Stack trace.
- */
-#define	INKERNEL(va) (((va) >= DMAP_MIN_ADDRESS && (va) < DMAP_MAX_ADDRESS) \
-	    || ((va) >= KERNBASE && (va) < VM_MAX_KERNEL_ADDRESS))
-
-struct amd64_frame {
-	struct amd64_frame	*f_frame;
-	long			f_retaddr;
-	long			f_arg0;
-};
-
 #define NORMAL		0
 #define	TRAP		1
 #define	INTERRUPT	2
@@ -505,32 +494,6 @@ db_trace_thread(struct thread *thr, int count)
 		    ctx->pcb_rip, count));
 }
 
-void
-stack_save(struct stack *st)
-{
-	struct amd64_frame *frame;
-	vm_offset_t callpc;
-	register_t rbp;
-
-	stack_zero(st);
-	__asm __volatile("movq %%rbp,%0" : "=r" (rbp));
-	frame = (struct amd64_frame *)rbp;
-	while (1) {
-		if (!INKERNEL((long)frame))
-			break;
-		callpc = frame->f_retaddr;
-		if (!INKERNEL(callpc))
-			break;
-		if (stack_put(st, callpc) == -1)
-			break;
-		if (frame->f_frame <= frame ||
-		    (vm_offset_t)frame->f_frame >=
-		    (vm_offset_t)rbp + KSTACK_PAGES * PAGE_SIZE)
-			break;
-		frame = frame->f_frame;
-	}
-}
-
 int
 amd64_set_watch(watchnum, watchaddr, size, access, d)
 	int watchnum;