From 2e520bb87bfd6803f44a840ec87e099b1785e364 Mon Sep 17 00:00:00 2001
From: "laudney@eclipse.(none)" <laudney@eclipse.(none)>
Date: Thu, 13 Nov 2003 12:25:31 +0000
Subject: [PATCH] bitkeeper revision 1.599 (3fb3783bCzU2OI0iS1r2i_GVLKRG0Q)

Fixes. Xen console buffer ring can be cleared at request.
---
 tools/internal/xi_read_console_ring.c | 29 +++++++++++++++++++--------
 xen/common/console.c                  | 13 ++++++------
 xen/common/dom0_ops.c                 |  5 +++--
 xen/include/hypervisor-ifs/dom0_ops.h |  1 +
 xen/include/xeno/console.h            | 11 +++++++---
 5 files changed, 39 insertions(+), 20 deletions(-)

diff --git a/tools/internal/xi_read_console_ring.c b/tools/internal/xi_read_console_ring.c
index eaa73aed92..b8ddf0695f 100644
--- a/tools/internal/xi_read_console_ring.c
+++ b/tools/internal/xi_read_console_ring.c
@@ -4,10 +4,12 @@
 
 #include "dom0_defs.h"
 
-#define CONSOLE_RING_SIZE 16392
+#define CONSOLE_RING_SIZE	16392
+#define CONSOLE_RING_CLEAR	1
+
 static char *argv0 = "read_console_ring";
 
-static long read_console_ring(unsigned long str, unsigned count)
+static long read_console_ring(unsigned long str, unsigned count, unsigned int cmd)
 {
     int ret;
     dom0_op_t op;
@@ -15,6 +17,7 @@ static long read_console_ring(unsigned long str, unsigned count)
     op.cmd = DOM0_READCONSOLE;
     op.u.readconsole.str = str;
     op.u.readconsole.count = count;
+    op.u.readconsole.cmd = cmd;
 
     ret = do_dom0_op(&op);
     if (ret > 0) {
@@ -26,22 +29,32 @@ static long read_console_ring(unsigned long str, unsigned count)
 
 int main(int argc, char **argv)
 {
-    char str[CONSOLE_RING_SIZE];
-
+    char str[CONSOLE_RING_SIZE+1];
+    unsigned int cmd = 0;
+    
     if ( argv[0] != NULL ) 
         argv0 = argv[0];
     
-    if ( argc > 2) {
-        fprintf(stderr, "Usage: %s [-r]\n", argv0);
+    if ( argc > 2 || (argc == 2 && strcmp(argv[1], "-c")) ) {
+        fprintf(stderr, "Usage: %s [-c]\n", argv0);
+        return 1;
+    }
+
+    if ( argc == 2) {
+	cmd |= CONSOLE_RING_CLEAR;
+    }
+    
+    if ( mlock(str, CONSOLE_RING_SIZE+1) != 0) {
+        PERROR("Could not lock memory for user space read console ring buffer");
         return 1;
     }
     
-    if ( read_console_ring((unsigned long)str, CONSOLE_RING_SIZE) < 0 ) {
+    if ( read_console_ring((unsigned long)str, CONSOLE_RING_SIZE, cmd) < 0 ) {
 	printf("Read console ring error.\n");
-	printf("%s", str);
         return 1;
     }
 
     printf("%s", str);
+	
     return 0;
 }
diff --git a/xen/common/console.c b/xen/common/console.c
index f6e3f250bb..d52a8cf3be 100644
--- a/xen/common/console.c
+++ b/xen/common/console.c
@@ -12,19 +12,18 @@ console_ring_t console_ring = {
     .len = 0
 };
 
-void init_console_ring()
-{
-    console_ring.len = 0;
-}
-
-long read_console_ring(unsigned long str, unsigned int count)
+long read_console_ring(unsigned long str, unsigned int count, unsigned cmd)
 {
     unsigned int len;
     
-    len = (console_ring.len < count)? console_ring.len : count;
+    len = (console_ring.len < count) ? console_ring.len : count;
     
     if ( copy_to_user((char *)str, console_ring.buf, len) )
         return -EFAULT;
 
+    if ( cmd & CONSOLE_RING_CLEAR ) {
+	console_ring.len = 0;
+    }
+    
     return len;
 }
diff --git a/xen/common/dom0_ops.c b/xen/common/dom0_ops.c
index 0558a1e40b..8db4b5fedb 100644
--- a/xen/common/dom0_ops.c
+++ b/xen/common/dom0_ops.c
@@ -415,9 +415,10 @@ long do_dom0_op(dom0_op_t *u_dom0_op)
     
     case DOM0_READCONSOLE:
     {
-    	extern long read_console_ring(unsigned long, unsigned int);
+    	extern long read_console_ring(unsigned long, unsigned int, unsigned int);
         ret = read_console_ring(op.u.readconsole.str, 
-                         	op.u.readconsole.count); 
+                         	op.u.readconsole.count,
+				op.u.readconsole.cmd); 
     }
     break;    
 
diff --git a/xen/include/hypervisor-ifs/dom0_ops.h b/xen/include/hypervisor-ifs/dom0_ops.h
index 770305f6ac..2c3d12ab78 100644
--- a/xen/include/hypervisor-ifs/dom0_ops.h
+++ b/xen/include/hypervisor-ifs/dom0_ops.h
@@ -194,6 +194,7 @@ typedef struct dom0_readconsole_st
 {
     unsigned long str;
     unsigned int count;
+    unsigned int cmd;
 } dom0_readconsole_t;
 
 typedef struct dom0_op_st
diff --git a/xen/include/xeno/console.h b/xen/include/xeno/console.h
index 589754d08a..375c4b2215 100644
--- a/xen/include/xeno/console.h
+++ b/xen/include/xeno/console.h
@@ -6,6 +6,9 @@
  * Copyright (c) 2003 James Scott, Intel Research Cambridge
  */
 
+#ifndef __CONSOLE_H__
+#define __CONSOLE_H__
+
 /*
  * Ownership of console --- currently hardwired to dom0. This is used to see 
  * who gets the PS/2 keyboard/mouse events
@@ -43,7 +46,8 @@
 
 extern int opt_console;
 
-#define CONSOLE_RING_SIZE     16392
+#define CONSOLE_RING_SIZE	16392
+#define CONSOLE_RING_CLEAR	1
 
 typedef struct console_ring_st
 {
@@ -53,5 +57,6 @@ typedef struct console_ring_st
 
 extern console_ring_t console_ring;
 
-void init_console_ring();
-long read_console_ring(unsigned long, unsigned int);
+long read_console_ring(unsigned long, unsigned int, unsigned int);
+
+#endif
-- 
2.30.2