6 files changed, 47 insertions, 59 deletions

diff --git a/sys/ddb/db_command.c b/sys/ddb/db_command.c
index c15edaa97148..c92d52fa2aff 100644
--- a/sys/ddb/db_command.c
+++ b/sys/ddb/db_command.c
@@ -392,8 +392,9 @@ db_command(last_cmdp, cmd_table)
 	    /*
 	     * Execute the command.
 	     */
+	    db_enable_pager();
 	    (*cmd->fcn)(addr, have_addr, count, modif);
-	    db_setup_paging(NULL, NULL, -1);
+	    db_disable_pager();
 
 	    if (cmd->flag & CS_SET_DOT) {
 		/*
@@ -675,16 +676,13 @@ db_stack_trace_all(db_expr_t dummy, boolean_t dummy2, db_expr_t dummy3,
 {
 	struct proc *p;
 	struct thread *td;
-	int quit;
 
-	quit = 0;
-	db_setup_paging(db_simple_pager, &quit, db_lines_per_page);
 	LIST_FOREACH(p, &allproc, p_list) {
 		FOREACH_THREAD_IN_PROC(p, td) {
 			db_printf("\nTracing command %s pid %d tid %ld td %p\n",
 			    p->p_comm, p->p_pid, (long)td->td_tid, td);
 			db_trace_thread(td, -1);
-			if (quit)
+			if (db_pager_quit)
 				return;
 		}
 	}
diff --git a/sys/ddb/db_output.c b/sys/ddb/db_output.c
index fccae29db765..e9f0c824c9de 100644
--- a/sys/ddb/db_output.c
+++ b/sys/ddb/db_output.c
@@ -66,15 +66,15 @@ db_expr_t	db_tab_stop_width = 8;		/* how wide are tab stops? */
 	((((i) + db_tab_stop_width) / db_tab_stop_width) * db_tab_stop_width)
 db_expr_t	db_max_width = 79;		/* output line width */
 db_expr_t	db_lines_per_page = 20;		/* lines per page */
+volatile int	db_pager_quit;			/* user requested quit */
 static int	db_newlines;			/* # lines this page */
-static int	db_maxlines = -1;		/* max lines/page when paging */
-static db_page_calloutfcn_t *db_page_callout = NULL;
-static void	*db_page_callout_arg = NULL;
+static int	db_maxlines;			/* max lines/page when paging */
 static int	ddb_use_printf = 0;
 SYSCTL_INT(_debug, OID_AUTO, ddb_use_printf, CTLFLAG_RW, &ddb_use_printf, 0,
     "use printf for all ddb output");
 
 static void	db_putchar(int c, void *arg);
+static void	db_pager(void);
 
 /*
  * Force pending whitespace.
@@ -120,12 +120,10 @@ db_putchar(c, arg)
 			return;
 		if (c == '\r' || c == '\n')
 			db_check_interrupt();
-		if (c == '\n' && db_maxlines > 0 && db_page_callout != NULL) {
+		if (c == '\n' && db_maxlines > 0) {
 			db_newlines++;
-			if (db_newlines >= db_maxlines) {
-				db_maxlines = -1;
-				db_page_callout(db_page_callout_arg);
-			}
+			if (db_newlines >= db_maxlines)
+				db_pager();
 		}
 		return;
 	}
@@ -149,12 +147,10 @@ db_putchar(c, arg)
 	    db_output_position = 0;
 	    db_last_non_space = 0;
 	    db_check_interrupt();
-	    if (db_maxlines > 0 && db_page_callout != NULL) {
+	    if (db_maxlines > 0) {
 		    db_newlines++;
-		    if (db_newlines >= db_maxlines) {
-			    db_maxlines = -1;
-			    db_page_callout(db_page_callout_arg);
-		    }
+		    if (db_newlines >= db_maxlines)
+			    db_pager();
 	    }
 	}
 	else if (c == '\r') {
@@ -181,27 +177,34 @@ db_putchar(c, arg)
 }
 
 /*
- * Register callout for providing a pager for output.
+ * Turn on the pager.
  */
 void
-db_setup_paging(db_page_calloutfcn_t *callout, void *arg, int maxlines)
+db_enable_pager(void)
 {
-	
-	if (db_page_callout == NULL || callout == NULL || arg ==
-	    db_page_callout_arg) {
-		db_page_callout = callout;
-		db_page_callout_arg = arg;
-		db_maxlines = maxlines;
+	if (db_maxlines == 0) {
+		db_maxlines = db_lines_per_page;
 		db_newlines = 0;
+		db_pager_quit = 0;
 	}
 }
 
 /*
- * A simple paging callout function.  If the argument is not null, it
- * points to an integer that will be set to 1 if the user asks to quit.
+ * Turn off the pager.
  */
 void
-db_simple_pager(void *arg)
+db_disable_pager(void)
+{
+	db_maxlines = 0;
+}
+
+/*
+ * A simple paging callout function.  It supports several simple more(1)-like
+ * commands as well as a quit command that sets db_pager_quit which db
+ * commands can poll to see if they should terminate early.
+ */
+void
+db_pager(void)
 {
 	int c, done;
 
@@ -214,20 +217,18 @@ db_simple_pager(void *arg)
 		case 'j':
 		case '\n':
 			/* Just one more line. */
-			db_setup_paging(db_simple_pager, arg, 1);
+			db_maxlines = 1;
 			done++;
 			break;
 		case 'd':
 			/* Half a page. */
-			db_setup_paging(db_simple_pager, arg,
-			    db_lines_per_page / 2);
+			db_maxlines = db_lines_per_page / 2;
 			done++;
 			break;
 		case 'f':
 		case ' ':
 			/* Another page. */
-			db_setup_paging(db_simple_pager, arg,
-			    db_lines_per_page);
+			db_maxlines = db_lines_per_page;
 			done++;
 			break;
 		case 'q':
@@ -235,11 +236,10 @@ db_simple_pager(void *arg)
 		case 'x':
 		case 'X':
 			/* Quit */
-			if (arg != NULL) {
-				*(int *)arg = 1;
-				done++;
-				break;
-			}
+			db_maxlines = 0;
+			db_pager_quit = 1;
+			done++;
+			break;
 #if 0
 			/* FALLTHROUGH */
 		default:
@@ -248,6 +248,7 @@ db_simple_pager(void *arg)
 		}
 	}
 	db_printf("        \r");
+	db_newlines = 0;
 }
 
 /*
diff --git a/sys/ddb/db_output.h b/sys/ddb/db_output.h
index 7615ea67f6cd..480c40d73af8 100644
--- a/sys/ddb/db_output.h
+++ b/sys/ddb/db_output.h
@@ -38,6 +38,8 @@
  * Printing routines for kernel debugger.
  */
 
+void	db_disable_pager(void);
+void	db_enable_pager(void);
 void	db_end_line(void);
 void	db_force_whitespace(void);
 int	db_print_position(void);
diff --git a/sys/ddb/db_ps.c b/sys/ddb/db_ps.c
index 39dff4c41135..f220de0ec056 100644
--- a/sys/ddb/db_ps.c
+++ b/sys/ddb/db_ps.c
@@ -73,23 +73,21 @@ db_ps(db_expr_t addr, boolean_t hasaddr, db_expr_t count, char *modif)
 	struct ucred *cred;
 	struct pgrp *pgrp;
 	char state[9];
-	int np, quit, rflag, sflag, dflag, lflag, wflag;
+	int np, rflag, sflag, dflag, lflag, wflag;
 
 	np = nprocs;
-	quit = 0;
 
 	if (!LIST_EMPTY(&allproc))
 		p = LIST_FIRST(&allproc);
 	else
 		p = &proc0;
 
-	db_setup_paging(db_simple_pager, &quit, db_lines_per_page);
 #ifdef __LP64__
 	db_printf(" pid   uid  ppid  pgrp  state   wmesg          wchan        cmd\n");
 #else
 	db_printf(" pid   uid  ppid  pgrp  state   wmesg      wchan    cmd\n");
 #endif
-	while (--np >= 0 && !quit) {
+	while (--np >= 0 && !db_pager_quit) {
 		if (p == NULL) {
 			db_printf("oops, ran out of processes early!\n");
 			break;
@@ -191,7 +189,7 @@ db_ps(db_expr_t addr, boolean_t hasaddr, db_expr_t count, char *modif)
 #endif
 		FOREACH_THREAD_IN_PROC(p, td) {
 			dumpthread(p, td, p->p_flag & P_HADTHREADS);
-			if (quit)
+			if (db_pager_quit)
 				break;
 		}
 
@@ -363,7 +361,7 @@ DB_SHOW_COMMAND(proc, db_show_proc)
 {
 	struct thread *td;
 	struct proc *p;
-	int i, quit;
+	int i;
 
 	/* Determine which process to examine. */
 	if (have_addr)
@@ -371,8 +369,6 @@ DB_SHOW_COMMAND(proc, db_show_proc)
 	else
 		p = kdb_thread->td_proc;
 
-	quit = 0;
-	db_setup_paging(db_simple_pager, &quit, db_lines_per_page);
 	db_printf("Process %d (%s) at %p:\n", p->p_pid, p->p_comm, p);
 	db_printf(" state: ");
 	switch (p->p_state) {
@@ -411,7 +407,7 @@ DB_SHOW_COMMAND(proc, db_show_proc)
 	db_printf(" threads: %d\n", p->p_numthreads);
 	FOREACH_THREAD_IN_PROC(p, td) {
 		dumpthread(p, td, 1);
-		if (quit)
+		if (db_pager_quit)
 			break;
 	}
 }
diff --git a/sys/ddb/db_thread.c b/sys/ddb/db_thread.c
index a946dd81f3df..13c3878f8ab2 100644
--- a/sys/ddb/db_thread.c
+++ b/sys/ddb/db_thread.c
@@ -93,13 +93,9 @@ db_show_threads(db_expr_t addr, boolean_t hasaddr, db_expr_t cnt, char *mod)
 	jmp_buf jb;
 	void *prev_jb;
 	struct thread *thr;
-	int pager_quit;
 
-	db_setup_paging(db_simple_pager, &pager_quit, db_lines_per_page);
-
-	pager_quit = 0;
 	thr = kdb_thr_first();
-	while (!pager_quit && thr != NULL) {
+	while (!db_pager_quit && thr != NULL) {
 		db_printf("  %6ld (%p)  ", (long)thr->td_tid, thr);
 		prev_jb = kdb_jmpbuf(jb);
 		if (setjmp(jb) == 0) {
diff --git a/sys/ddb/ddb.h b/sys/ddb/ddb.h
index 549e24e0b727..716740bfec40 100644
--- a/sys/ddb/ddb.h
+++ b/sys/ddb/ddb.h
@@ -52,8 +52,6 @@ int	DB_CALL(db_expr_t, db_expr_t *, int, db_expr_t[]);
 typedef void db_cmdfcn_t(db_expr_t addr, boolean_t have_addr, db_expr_t count,
 	    char *modif);
 
-typedef void db_page_calloutfcn_t(void *arg);
-
 #define DB_COMMAND(cmd_name, func_name) \
 	DB_FUNC(cmd_name, func_name, db_cmd_set, 0, NULL)
 #define DB_SHOW_COMMAND(cmd_name, func_name) \
@@ -85,6 +83,7 @@ extern int db_indent;
 extern int db_inst_count;
 extern int db_load_count;
 extern int db_store_count;
+extern volatile int db_pager_quit;
 extern db_expr_t db_radix;
 extern db_expr_t db_max_width;
 extern db_expr_t db_tab_stop_width;
@@ -118,8 +117,6 @@ int		db_readline(char *lstart, int lsize);
 void		db_restart_at_pc(boolean_t watchpt);
 int		db_set_variable(db_expr_t value);
 void		db_set_watchpoints(void);
-void		db_setup_paging(db_page_calloutfcn_t *callout, void *arg,
-				int maxlines);
 void		db_skip_to_eol(void);
 boolean_t	db_stop_at_pc(boolean_t *is_breakpoint);
 #define		db_strcpy	strcpy
@@ -149,8 +146,6 @@ db_cmdfcn_t	db_trace_until_matching_cmd;
 db_cmdfcn_t	db_watchpoint_cmd;
 db_cmdfcn_t	db_write_cmd;
 
-db_page_calloutfcn_t db_simple_pager;
-
 /*
  * Command table.
  */