Reject unreasonable values passed to CONS_HISTORY ioctl. It did not

check the value and caused kernel panic when a large value was given.

- Move the configuration option SC_HISTORY_SIZE from syscons.h to
syscons.c.
- Define the maximum total number of history lines of all consoles.
It is SC_HISTORY_SIZE*MAXCONS or 1000*MAXCONS; whichever is larger.
CONS_HISTORY will allow the user to set the history size up to
SC_HISTORY_SIZE unconditionally (or the current height of the console
if it is larger than SC_HISTORY_SIZE). If the user requests a larger
buffer, it will be granted only if the total number of all allocated
history lines and the requested number of lines won't exceed the maximum.
- Don't free the previous history buffer and leave the history buffer
pointer holding a invalid pointer. Set the pointer to NULL first, then
free the buffer.

PR: bin/4592

1 files changed, 1 insertions, 5 deletions

diff --git a/sys/isa/syscons.h b/sys/isa/syscons.h
index 0c74c32..ccddf83 100644
--- a/sys/isa/syscons.h
+++ b/sys/isa/syscons.h
@@ -25,7 +25,7 @@
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
- *	$Id: syscons.h,v 1.33 1997/09/04 23:01:06 yokota Exp $
+ *	$Id: syscons.h,v 1.34 1997/10/01 20:46:29 sos Exp $
  */
 
 #ifndef _I386_ISA_SYSCONS_H_
@@ -102,10 +102,6 @@
 #define FONT_8		2
 #define FONT_14		4
 #define FONT_16		8
-#if !defined(SC_HISTORY_SIZE)
-#define SC_HISTORY_SIZE	(ROW * 4)
-#endif /* SC_HISTORY_SIZE */
-#define HISTORY_SIZE	(COL * (SC_HISTORY_SIZE))
 
 /* defines related to hardware addresses */
 #define	MONO_BASE	0x3B4			/* crt controller base mono */